Search results for: phase formation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7157

Search results for: phase formation

287 Development and Experimental Evaluation of a Semiactive Friction Damper

Authors: Juan S. Mantilla, Peter Thomson

Abstract:

Seismic events may result in discomfort on occupants of the buildings, structural damage or even buildings collapse. Traditional design aims to reduce dynamic response of structures by increasing stiffness, thus increasing the construction costs and the design forces. Structural control systems arise as an alternative to reduce these dynamic responses. A commonly used control systems in buildings are the passive friction dampers, which adds energy dissipation through damping mechanisms induced by sliding friction between their surfaces. Passive friction dampers are usually implemented on the diagonal of braced buildings, but such devices have the disadvantage that are optimal for a range of sliding force and out of that range its efficiency decreases. The above implies that each passive friction damper is designed, built and commercialized for a specific sliding/clamping force, in which the damper shift from a locked state to a slip state, where dissipates energy through friction. The risk of having a variation in the efficiency of the device according to the sliding force is that the dynamic properties of the building can change as result of many factor, even damage caused by a seismic event. In this case the expected forces in the building can change and thus considerably reduce the efficiency of the damper (that is designed for a specific sliding force). It is also evident than when a seismic event occurs the forces in each floor varies in the time what means that the damper's efficiency is not the best at all times. Semi-Active Friction devices adapt its sliding force trying to maintain its motion in the slipping phase as much as possible, because of this, the effectiveness of the device depends on the control strategy used. This paper deals with the development and performance evaluation of a low cost Semiactive Variable Friction Damper (SAVFD) in reduced scale to reduce vibrations of structures subject to earthquakes. The SAVFD consist in a (1) hydraulic brake adapted to (2) a servomotor which is controlled with an (3) Arduino board and acquires accelerations or displacement from (4) sensors in the immediately upper and lower floors and a (5) power supply that can be a pair of common batteries. A test structure, based on a Benchmark structure for structural control, was design and constructed. The SAVFD and the structure are experimentally characterized. A numerical model of the structure and the SAVFD is developed based on the dynamic characterization. Decentralized control algorithms were modeled and later tested experimentally using shaking table test using earthquake and frequency chirp signals. The controlled structure with the SAVFD achieved reductions greater than 80% in relative displacements and accelerations in comparison to the uncontrolled structure.

Keywords: earthquake response, friction damper, semiactive control, shaking table

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286 Inhibition of Mild Steel Corrosion in Hydrochloric Acid Medium Using an Aromatic Hydrazide Derivative

Authors: Preethi Kumari P., Shetty Prakasha, Rao Suma A.

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Mild steel has been widely employed as construction materials for pipe work in the oil and gas production such as down hole tubular, flow lines and transmission pipelines, in chemical and allied industries for handling acids, alkalis and salt solutions due to its excellent mechanical property and low cost. Acid solutions are widely used for removal of undesirable scale and rust in many industrial processes. Among the commercially available acids hydrochloric acid is widely used for pickling, cleaning, de-scaling and acidization of oil process. Mild steel exhibits poor corrosion resistance in presence of hydrochloric acid. The high reactivity of mild steel in presence of hydrochloric acid is due to the soluble nature of ferrous chloride formed and the cementite phase (Fe3C) normally present in the steel is also readily soluble in hydrochloric acid. Pitting attack is also reported to be a major form of corrosion in mild steel in the presence of high concentrations of acids and thereby causing the complete destruction of metal. Hydrogen from acid reacts with the metal surface and makes it brittle and causes cracks, which leads to pitting type of corrosion. The use of chemical inhibitor to minimize the rate of corrosion has been considered to be the first line of defense against corrosion. In spite of long history of corrosion inhibition, a highly efficient and durable inhibitor that can completely protect mild steel in aggressive environment is yet to be realized. It is clear from the literature review that there is ample scope for the development of new organic inhibitors, which can be conveniently synthesized from relatively cheap raw materials and provide good inhibition efficiency with least risk of environmental pollution. The aim of the present work is to evaluate the electrochemical parameters for the corrosion inhibition behavior of an aromatic hydrazide derivative, 4-hydroxy- N '-[(E)-1H-indole-2-ylmethylidene)] benzohydrazide (HIBH) on mild steel in 2M hydrochloric acid using Tafel polarization and electrochemical impedance spectroscopy (EIS) techniques at 30-60 °C. The results showed that inhibition efficiency increased with increase in inhibitor concentration and decreased marginally with increase in temperature. HIBH showed a maximum inhibition efficiency of 95 % at 8×10-4 M concentration at 30 °C. Polarization curves showed that HIBH act as a mixed-type inhibitor. The adsorption of HIBH on mild steel surface obeys the Langmuir adsorption isotherm. The adsorption process of HIBH at the mild steel/hydrochloric acid solution interface followed mixed adsorption with predominantly physisorption at lower temperature and chemisorption at higher temperature. Thermodynamic parameters for the adsorption process and kinetic parameters for the metal dissolution reaction were determined.

Keywords: electrochemical parameters, EIS, mild steel, tafel polarization

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285 Establishing Correlation between Urban Heat Island and Urban Greenery Distribution by Means of Remote Sensing and Statistics Data to Prioritize Revegetation in Yerevan

Authors: Linara Salikhova, Elmira Nizamova, Aleksandra Katasonova, Gleb Vitkov, Olga Sarapulova.

Abstract:

While most European cities conduct research on heat-related risks, there is a research gap in the Caucasus region, particularly in Yerevan, Armenia. This study aims to test the method of establishing a correlation between urban heat islands (UHI) and urban greenery distribution for prioritization of heat-vulnerable areas for revegetation. Armenia has failed to consider measures to mitigate UHI in urban development strategies despite a 2.1°C increase in average annual temperature over the past 32 years. However, planting vegetation in the city is commonly used to deal with air pollution and can be effective in reducing UHI if it prioritizes heat-vulnerable areas. The research focuses on establishing such priorities while considering the distribution of urban greenery across the city. The lack of spatially explicit air temperature data necessitated the use of satellite images to achieve the following objectives: (1) identification of land surface temperatures (LST) and quantification of temperature variations across districts; (2) classification of massifs of land surface types using normalized difference vegetation index (NDVI); (3) correlation of land surface classes with LST. Examination of the heat-vulnerable city areas (in this study, the proportion of individuals aged 75 years and above) is based on demographic data (Census 2011). Based on satellite images (Sentinel-2) captured on June 5, 2021, NDVI calculations were conducted. The massifs of the land surface were divided into five surface classes. Due to capacity limitations, the average LST for each district was identified using one satellite image from Landsat-8 on August 15, 2021. In this research, local relief is not considered, as the study mainly focuses on the interconnection between temperatures and green massifs. The average temperature in the city is 3.8°C higher than in the surrounding non-urban areas. The temperature excess ranges from a low in Norq Marash to a high in Nubarashen. Norq Marash and Avan have the highest tree and grass coverage proportions, with 56.2% and 54.5%, respectively. In other districts, the balance of wastelands and buildings is three times higher than the grass and trees, ranging from 49.8% in Quanaqer-Zeytun to 76.6% in Nubarashen. Studies have shown that decreased tree and grass coverage within a district correlates with a higher temperature increase. The temperature excess is highest in Erebuni, Ajapnyak, and Nubarashen districts. These districts have less than 25% of their area covered with grass and trees. On the other hand, Avan and Norq Marash districts have a lower temperature difference, as more than 50% of their areas are covered with trees and grass. According to the findings, a significant proportion of the elderly population (35%) aged 75 years and above reside in the Erebuni, Ajapnyak, and Shengavit neighborhoods, which are more susceptible to heat stress with an LST higher than in other city districts. The findings suggest that the method of comparing the distribution of green massifs and LST can contribute to the prioritization of heat-vulnerable city areas for revegetation. The method can become a rationale for the formation of an urban greening program.

Keywords: heat-vulnerability, land surface temperature, urban greenery, urban heat island, vegetation

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284 An Analysis of Teacher Knowledge of Recognizing and Addressing the Needs of Traumatized Students

Authors: Tiffany Hollis

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Childhood trauma is well documented in mental health research, yet has received little attention in urban schools. Child trauma affects brain development and impacts cognitive, emotional, and behavioral functioning. When educators understand that some of the behaviors that appear to be aggressive in nature might be the result of a hidden diagnosis of trauma, learning can take place, and the child can thrive in the classroom setting. Traumatized children, however, do not fit neatly into any single ‘box.’ Although many children enter school each day carrying with them the experience of exposure to violence in the home, the symptoms of their trauma can be multifaceted and complex, requiring individualized therapeutic attention. The purpose of this study was to examine how prepared educators are to address the unique challenges facing children who experience trauma. Given the vast number of traumatized children in our society, it is evident that our education system must investigate ways to create an optimal learning environment that accounts for trauma, addresses its impact on cognitive and behavioral development, and facilitates mental and emotional health and well-being. The researcher describes the knowledge, attitudes, dispositions, and skills relating to trauma-informed knowledge of induction level teachers in a diverse middle school. The data for this study were collected through interviews with teachers, who are in the induction phase (the first three years of their teaching career). The study findings paint a clear picture of how ill-prepared educators are to address the needs of students who have experienced trauma and the implications for the development of a professional development workshop or series of workshops that train teachers how to recognize and address and respond to the needs of students. The study shows how teachers often lack skills to meet the needs of students who have experienced trauma. Traumatized children regularly carry a heavy weight on their shoulders. Children who have experienced trauma may feel that the world is filled with unresponsive, threatening adults, and peers. Despite this, supportive interventions can provide traumatized children with places to go that are safe, stimulating, and even fun. Schools offer an environment that potentially meets these requirements by creating safe spaces where students can feel at ease and have fun while also learning via stimulating educational activities. This study highlights the lack of preparedness of educators to address the academic, behavioral, and cognitive needs of students who have experienced trauma. These findings provide implications for the creation of a professional development workshop that addresses how to recognize and address the needs of students who have experienced some type of trauma. They also provide implications for future research with a focus on specific interventions that enable the creation of optimal learning environments where students who have experienced trauma and all students can succeed, regardless of their life experiences.

Keywords: educator preparation, induction educators, professional development, trauma-informed

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283 Leuco Dye-Based Thermochromic Systems for Application in Temperature Sensing

Authors: Magdalena Wilk-Kozubek, Magdalena Rowińska, Krzysztof Rola, Joanna Cybińska

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Leuco dye-based thermochromic systems are classified as intelligent materials because they exhibit thermally induced color changes. Thanks to this feature, they are mainly used as temperature sensors in many industrial sectors. For example, placing a thermochromic material on a chemical reactor may warn about exceeding the maximum permitted temperature for a chemical process. Usually two components, a color former and a developer are needed to produce a system with irreversible color change. The color former is an electron donating (proton accepting) compound such as fluoran leuco dye. The developer is an electron accepting (proton donating) compound such as organic carboxylic acid. When the developer melts, the color former - developer complex is created and the termochromic system becomes colored. Typically, the melting point of the applied developer determines the temperature at which the color change occurs. When the lactone ring of the color former is closed, then the dye is in its colorless state. The ring opening, induced by the addition of a proton, causes the dye to turn into its colored state. Since the color former and the developer are often solid, they can be incorporated into polymer films to facilitate their practical use in industry. The objective of this research was to fabricate a leuco dye-based termochromic system that will irreversibly change color after reaching the temperature of 100°C. For this purpose, benzofluoran leuco dye (as color former) and phenoxyacetic acid (as developer with a melting point of 100°C) were introduced into the polymer films during the drop casting process. The film preparation process was optimized in order to obtain thin films with appropriate properties such as transparency, flexibility and homogeneity. Among the optimized factors were the concentration of benzofluoran leuco dye and phenoxyacetic acid, the type, average molecular weight and concentration of the polymer, and the type and concentration of the surfactant. The selected films, containing benzofluoran leuco dye and phenoxyacetic acid, were combined by mild heat treatment. Structural characterization of single and combined films was carried out by FTIR spectroscopy, morphological analysis was performed by optical microscopy and SEM, phase transitions were examined by DSC, color changes were investigated by digital photography and UV-Vis spectroscopy, while emission changes were studied by photoluminescence spectroscopy. The resulting thermochromic system is colorless at room temperature, but after reaching 100°C the developer melts and it turns irreversibly pink. Therefore, it could be used as an additional sensor to warn against boiling of water in power plants using water cooling. Currently used electronic temperature indicators are prone to faults and unwanted third-party actions. The sensor constructed in this work is transparent, thanks to which it can be unnoticed by an outsider and constitute a reliable reference for the person responsible for the apparatus.

Keywords: color developer, leuco dye, thin film, thermochromism

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282 Quantum Dots Incorporated in Biomembrane Models for Cancer Marker

Authors: Thiago E. Goto, Carla C. Lopes, Helena B. Nader, Anielle C. A. Silva, Noelio O. Dantas, José R. Siqueira Jr., Luciano Caseli

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Quantum dots (QD) are semiconductor nanocrystals that can be employed in biological research as a tool for fluorescence imagings, having the potential to expand in vivo and in vitro analysis as cancerous cell biomarkers. Particularly, cadmium selenide (CdSe) magic-sized quantum dots (MSQDs) exhibit stable luminescence that is feasible for biological applications, especially for imaging of tumor cells. For these facts, it is interesting to know the mechanisms of action of how such QDs mark biological cells. For that, simplified models are a suitable strategy. Among these models, Langmuir films of lipids formed at the air-water interface seem to be adequate since they can mimic half a membrane. They are monomolecular films formed at liquid-gas interfaces that can spontaneously form when organic solutions of amphiphilic compounds are spread on the liquid-gas interface. After solvent evaporation, the monomolecular film is formed, and a variety of techniques, including tensiometric, spectroscopic and optic can be applied. When the monolayer is formed by membrane lipids at the air-water interface, a model for half a membrane can be inferred where the aqueous subphase serve as a model for external or internal compartment of the cell. These films can be transferred to solid supports forming the so-called Langmuir-Blodgett (LB) films, and an ampler variety of techniques can be additionally used to characterize the film, allowing for the formation of devices and sensors. With these ideas in mind, the objective of this work was to investigate the specific interactions of CdSe MSQDs with tumorigenic and non-tumorigenic cells using Langmuir monolayers and LB films of lipids and specific cell extracts as membrane models for diagnosis of cancerous cells. Surface pressure-area isotherms and polarization modulation reflection-absorption spectroscopy (PM-IRRAS) showed an intrinsic interaction between the quantum dots, inserted in the aqueous subphase, and Langmuir monolayers, constructed either of selected lipids or of non-tumorigenic and tumorigenic cells extracts. The quantum dots expanded the monolayers and changed the PM-IRRAS spectra for the lipid monolayers. The mixed films were then compressed to high surface pressures and transferred from the floating monolayer to solid supports by using the LB technique. Images of the films were then obtained with atomic force microscopy (AFM) and confocal microscopy, which provided information about the morphology of the films. Similarities and differences between films with different composition representing cell membranes, with or without CdSe MSQDs, was analyzed. The results indicated that the interaction of quantum dots with the bioinspired films is modulated by the lipid composition. The properties of the normal cell monolayer were not significantly altered, whereas for the tumorigenic cell monolayer models, the films presented significant alteration. The images therefore exhibited a stronger effect of CdSe MSQDs on the models representing cancerous cells. As important implication of these findings, one may envisage for new bioinspired surfaces based on molecular recognition for biomedical applications.

Keywords: biomembrane, langmuir monolayers, quantum dots, surfaces

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281 Fashion Utopias: The Role of Fashion Exhibitions and Fashion Archives to Defining (and Stimulating) Possible Future Fashion Landscapes

Authors: Vittorio Linfante

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Utopìa is a term that, since its first appearance in 1516, in Tommaso Moro’s work, has taken on different meanings and forms in various fields: social studies, politics, art, creativity, and design. The utopias, although of short duration and in their apparent impossibility, have been able to give a shape to the future, laying the foundations for our present and the future of the next generations. The Twentieth century was the historical period crossed by many changes, and it saw the most significant number of utopias not only social, political, and scientific but also artistic, architectural, in design, communication, and, last but not least, in fashion. Over the years, fashion has been able to interpret various utopistic impulses giving form to the most futuristic visions. From the Manifesto del Vestito by Giacomo Balla, through the functional experiments that led to the Tuta by Thayath and the Varst by Aleksandr Rodčenko and Varvara Stepanova, through the Space Age visions of Rudi Gernreich, Paco Rabanne and Pierre Cardin, and the Archizoom’s political actions and their fashion project Vestirsi è facile. Experiments that have continued to the present days through the (sometimes) excessive visions of Hussein Chalayan, Alexander McQueen, and Gareth Pugh or those that are more anchored to the market (but no fewer innovative and visionaries) by Prada, Chanel, and Raf Simmons. If, as Bauman states, it is true that we have entered in a phase of Retrotopia characterized by the inability to think about new forms of the future; it is necessary, more than ever, to redefine the role of history, of its narration and its mise en scène, within the contemporary creative process. A process that increasingly requires an in-depth knowledge of the past for the definition of a renewed discourse about design processes. A discourse in which words like archive, exhibition, curating, revival, vintage, and costume take on new meanings. The paper aims to investigate–through case studies, research, and professional projects–the renewed role of curating and preserving fashion artefacts. A renewed role that–in an era of Retrotopia–museums, exhibitions, and archives can (and must) assume, to contribute to the definition of new design paradigms, capable of overcoming the traditional categories of revival or costume in favour of a more contemporary “mash-up” approach. Mash-up in which past and present, craftsmanship and new technologies, revival and experimentation merge seamlessly. In this perspective, dresses (as well as fashion accessories) should be considered not only as finished products but as artefacts capable of talking about the past and of producing unpublished new stories at the same time. Archives, exhibitions (academic and not), and museums thus become powerful sources of inspiration for fashion: places and projects capable of generating innovation, becoming active protagonists of the contemporary fashion design processes.

Keywords: heritage, history, costume and fashion interface, performance, language, design research

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280 Pentosan Polysulfate Sodium: A Potential Treatment to Improve Bone and Joint Manifestations of Mucopolysaccharidosis I

Authors: Drago Bratkovic, Curtis Gravance, David Ketteridge, Ravi Krishnan, Michael Imperiale

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The mucopolysaccharidoses (MPSs) are a group of lysosomal storage diseases that have a common defect in the catabolism of glycosaminoglycans (GAGs). MPS I is the most common of the MPS diseases. Manifestations of MPS I include coarsening of facial features, corneal clouding, developmental delay, short stature, skeletal manifestations, hearing loss, cardiac valve disease, hepatosplenomegaly, and umbilical and inguinal hernias. Treatments for MPS I restore or activate the missing or deficient enzyme in the case of enzyme replacement therapy (ERT) and haematopoietic stem cell transplantation (HSCT). Pentosan polysulfate sodium (PPS) is a potential treatment to improve bone and joint manifestations of MPS I. The mechanisms of action of PPS that are relevant to the treatment of MPS I are the ability to: (i) Reduce systemic and accumulated GAG, (ii) Reduce inflammatory effects via the inhibition of NF-kB, resulting in the reduction in pro-inflammatory mediators. (iii) Reduce the expression of the pain mediator nerve growth factor in osteocytes from degenerating joints. (iv) Inhibit the cartilage degrading enzymes related to joint dysfunction in MPS I. PPS is being evaluated as an adjunctive therapy to ERT and/or HSCT in an open-label, single-centre, phase 2 study. Patients are ≥ 5 years of age with a diagnosis of MPS I and previously received HSCT and/or ERT. Three white, female, patients with MPS I-Hurler, ages 14, 15, and 19 years, and one, white male patient aged 15 years are enrolled. All were diagnosed at ≤2 years of age. All patients received HSCT ≤ 6 months after diagnosis. Two of the patients were treated with ERT prior to HSCT, and 1 patient received ERT commencing 3 months prior to HSCT. Two patients received 0.75mg/kg and 2 patients received 1.5mg/kg of PPS. PPS was well tolerated at doses of 0.75 and 1.5 mg/kg to 47 weeks of continuous dosing. Of the 19 adverse events (AEs), 2 were related to PPS. One AE was moderate (pre-syncope) and 1 was mild (injection site bruising), experienced in the same patient. All AEs were reported as mild or moderate. There have been no SAEs. One subject experienced a COVID-19 infection and PPS was interrupted. The MPS I signature GAG fragments, sulfated disaccharide and UA-HNAc S, tended to decrease in 3 patients from baseline through Week 25. Week 25 GAG data are pending for the 4th patient. Overall, most biomarkers (inflammatory, cartilage degeneration, and bone turnover) evaluated in the 3 patients with 25-week assessments have indicated either no change or a reduction in levels compared to baseline. In 3 patients, there was a trend toward improvement in the 2MWT from baseline to Week 48 with > 100% increase in 1 patient (01-201). In the 3 patients that had Week 48 assessments, patients and proxies reported improvement in PGIC, including “worthwhile difference” (n=1), or “made all the difference” (n=2).

Keywords: MPS I, pentosan polysulfate sodium, clinical study, 2MWT, QoL

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279 Mental Health on Three Continents: A Comparison of Mental Health Disorders in the Usa, India and Brazil

Authors: Henry Venter, Murali Thyloth, Alceu Casseb

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Historically, mental and substance use disorders were not a global health priority. Since the 1993 World Development Report, the importance of the contribution of mental health and substance abuse on the relative global burden associated with disease morbidity has been recognized with 300 million people worldwide suffering from depression alone. This led to an international effort to improve the mental health of populations around the world. Despite these efforts some countries remain at the top of the list of countries with the highest rate of mental illness. Important research questions were asked: Would there be commonalities regarding mental health between these countries; would there be common factors leading to the high prevalence of mental illness; and how prepared are these countries with mental health delivery? Findings from this research can aid organizations and institutions preparing mental health service providers to focus training and preparation to address specific needs revealed by the study. Methods: Researchers decided to compare three distinctly different countries at the top of the list of countries with the highest rate of mental illness, the USA, India and Brazil, situated on three different continents with different economies and lifestyles. Data were collected using archival research methodology, reviewing records and findings of international and national health and mental health studies to subtract and compare data and findings. Results: The findings indicated that India is the most depressed country in the world, followed by the USA (and China) with Brazil in Latin America with the greatest number of depressed individuals. By 2020 roughly 20% of India, acountry of over one billion citizens, will suffer from some form of mental illnees, yet there are less than 4,000 experts available. In the USA 164.8 million people were substance abusers and an estimate of 47.6 million adults, 18 or older, had any mental illness in 2018. That means that about one in five adults in the USA experiences some form of mental illness each year, but only 41% of those affected received mental health care or services in the past year. Brazil has the greatest number of depressed individuals, in Latin America. Adults living in Sao Paulo megacity has prevalence of mental disorders at greater levels than similar surveys conducted in other areas of the world with more than one million adults with serious impairment levels. Discussion: The results show that, despite the vast socioeconomic differences between the three countries, there are correlations regarding mental health prevalence and difficulty to provide adequate services including a lack of awareness of how serious mental illness is, stigma for seeking mental illness, with comorbidity a common phenomenon, and a lack of partnership between different levels of service providers, which weakens mental health service delivery. The findings also indicate that mental health training institutions have a monumental task to prepare personnel to address the future mental health needs in each of the countries compared, which will constitute the next phase of the research.

Keywords: mental health epidemiology, mental health disorder, mental health prevalence, mental health treatment

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278 Studies of the Reaction Products Resulted from Glycerol Electrochemical Conversion under Galvanostatic Mode

Authors: Ching Shya Lee, Mohamed Kheireddine Aroua, Wan Mohd Ashri Wan Daud, Patrick Cognet, Yolande Peres, Mohammed Ajeel

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In recent years, with the decreasing supply of fossil fuel, renewable energy has received a significant demand. Biodiesel which is well known as vegetable oil based fatty acid methyl ester is an alternative fuel for diesel. It can be produced from transesterification of vegetable oils, such as palm oil, sunflower oil, rapeseed oil, etc., with methanol. During the transesterification process, crude glycerol is formed as a by-product, resulting in 10% wt of the total biodiesel production. To date, due to the fast growing of biodiesel production in worldwide, the crude glycerol supply has also increased rapidly and resulted in a significant price drop for glycerol. Therefore, extensive research has been developed to use glycerol as feedstock to produce various added-value chemicals, such as tartronic acid, mesoxalic acid, glycolic acid, glyceric acid, propanediol, acrolein etc. The industrial processes that usually involved are selective oxidation, biofermentation, esterification, and hydrolysis. However, the conversion of glycerol into added-value compounds by electrochemical approach is rarely discussed. Currently, the approach is mainly focused on the electro-oxidation study of glycerol under potentiostatic mode for cogenerating energy with other chemicals. The electro-organic synthesis study from glycerol under galvanostatic mode is seldom reviewed. In this study, the glycerol was converted into various added-value compounds by electrochemical method under galvanostatic mode. This work aimed to study the possible compounds produced from glycerol by electrochemical technique in a one-pot electrolysis cell. The electro-organic synthesis study from glycerol was carried out in a single compartment reactor for 8 hours, over the platinum cathode and anode electrodes under acidic condition. Various parameters such as electric current (1.0 A to 3.0 A) and reaction temperature (27 °C to 80 °C) were evaluated. The products obtained were characterized by using gas chromatography-mass spectroscopy equipped with an aqueous-stable polyethylene glycol stationary phase column. Under the optimized reaction condition, the glycerol conversion achieved as high as 95%. The glycerol was successfully converted into various added-value chemicals such as ethylene glycol, glycolic acid, glyceric acid, acetaldehyde, formic acid, and glyceraldehyde; given the yield of 1%, 45%, 27%, 4%, 0.7% and 5%, respectively. Based on the products obtained from this study, the reaction mechanism of this process is proposed. In conclusion, this study has successfully converted glycerol into a wide variety of added-value compounds. These chemicals are found to have high market value; they can be used in the pharmaceutical, food and cosmetic industries. This study effectively opens a new approach for the electrochemical conversion of glycerol. For further enhancement on the product selectivity, electrode material is an important parameter to be considered.

Keywords: biodiesel, glycerol, electrochemical conversion, galvanostatic mode

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277 A Textile-Based Scaffold for Skin Replacements

Authors: Tim Bolle, Franziska Kreimendahl, Thomas Gries, Stefan Jockenhoevel

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The therapeutic treatment of extensive, deep wounds is limited. Autologous split-skin grafts are used as a so-called ‘gold standard’. Most common deficits are the defects at the donor site, the risk of scarring as well as the limited availability and quality of the autologous grafts. The aim of this project is a tissue engineered dermal-epidermal skin replacement to overcome the limitations of the gold standard. A key requirement for the development of such a three-dimensional implant is the formation of a functional capillary-like network inside the implant to ensure a sufficient nutrient and gas supply. Tailored three-dimensional warp knitted spacer fabrics are used to reinforce the mechanically week fibrin gel-based scaffold and further to create a directed in vitro pre-vascularization along the parallel-oriented pile yarns within a co-culture. In this study various three-dimensional warp knitted spacer fabrics were developed in a factorial design to analyze the influence of the machine parameters such as the stitch density and the pattern of the fabric on the scaffold performance and further to determine suitable parameters for a successful fibrin gel-incorporation and a physiological performance of the scaffold. The fabrics were manufactured on a Karl Mayer double-bar raschel machine DR 16 EEC/EAC. A fine machine gauge of E30 was used to ensure a high pile yarn density for sufficient nutrient, gas and waste exchange. In order to ensure a high mechanical stability of the graft, the fabrics were made of biocompatible PVDF yarns. Key parameters such as the pore size, porosity and stress/strain behavior were investigated under standardized, controlled climate conditions. The influence of the input parameters on the mechanical and morphological properties as well as the ability of fibrin gel incorporation into the spacer fabric was analyzed. Subsequently, the pile yarns of the spacer fabrics were colonized with Human Umbilical Vein Endothelial Cells (HUVEC) to analyze the ability of the fabric to further function as a guiding structure for a directed vascularization. The cells were stained with DAPI and investigated using fluorescence microscopy. The analysis revealed that the stitch density and the binding pattern have a strong influence on both the mechanical and morphological properties of the fabric. As expected, the incorporation of the fibrin gel was significantly improved with higher pore sizes and porosities, whereas the mechanical strength decreases. Furthermore, the colonization trials revealed a high cell distribution and density on the pile yarns of the spacer fabrics. For a tailored reinforcing structure, the minimum porosity and pore size needs to be evaluated which still ensures a complete incorporation of the reinforcing structure into the fibrin gel matrix. That will enable a mechanically stable dermal graft with a dense vascular network for a sufficient nutrient and oxygen supply of the cells. The results are promising for subsequent research in the field of reinforcing mechanically weak biological scaffolds and develop functional three-dimensional scaffolds with an oriented pre-vascularization.

Keywords: fibrin-gel, skin replacement, spacer fabric, pre-vascularization

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276 Applications of Digital Tools, Satellite Images and Geographic Information Systems in Data Collection of Greenhouses in Guatemala

Authors: Maria A. Castillo H., Andres R. Leandro, Jose F. Bienvenido B.

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During the last 20 years, the globalization of economies, population growth, and the increase in the consumption of fresh agricultural products have generated greater demand for ornamentals, flowers, fresh fruits, and vegetables, mainly from tropical areas. This market situation has demanded greater competitiveness and control over production, with more efficient protected agriculture technologies, which provide greater productivity and allow us to guarantee the quality and quantity that is required in a constant and sustainable way. Guatemala, located in the north of Central America, is one of the largest exporters of agricultural products in the region and exports fresh vegetables, flowers, fruits, ornamental plants, and foliage, most of which were grown in greenhouses. Although there are no official agricultural statistics on greenhouse production, several thesis works, and congress reports have presented consistent estimates. A wide range of protection structures and roofing materials are used, from the most basic and simple ones for rain control to highly technical and automated structures connected with remote sensors for monitoring and control of crops. With this breadth of technological models, it is necessary to analyze georeferenced data related to the cultivated area, to the different existing models, and to the covering materials, integrated with altitude, climate, and soil data. The georeferenced registration of the production units, the data collection with digital tools, the use of satellite images, and geographic information systems (GIS) provide reliable tools to elaborate more complete, agile, and dynamic information maps. This study details a methodology proposed for gathering georeferenced data of high protection structures (greenhouses) in Guatemala, structured in four phases: diagnosis of available information, the definition of the geographic frame, selection of satellite images, and integration with an information system geographic (GIS). It especially takes account of the actual lack of complete data in order to obtain a reliable decision-making system; this gap is solved through the proposed methodology. A summary of the results is presented in each phase, and finally, an evaluation with some improvements and tentative recommendations for further research is added. The main contribution of this study is to propose a methodology that allows to reduce the gap of georeferenced data in protected agriculture in this specific area where data is not generally available and to provide data of better quality, traceability, accuracy, and certainty for the strategic agricultural decision öaking, applicable to other crops, production models and similar/neighboring geographic areas.

Keywords: greenhouses, protected agriculture, GIS, Guatemala, satellite image, digital tools, precision agriculture

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275 Urban Heat Islands Analysis of Matera, Italy Based on the Change of Land Cover Using Satellite Landsat Images from 2000 to 2017

Authors: Giuseppina Anna Giorgio, Angela Lorusso, Maria Ragosta, Vito Telesca

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Climate change is a major public health threat due to the effects of extreme weather events on human health and on quality of life in general. In this context, mean temperatures are increasing, in particular, extreme temperatures, with heat waves becoming more frequent, more intense, and longer lasting. In many cities, extreme heat waves have drastically increased, giving rise to so-called Urban Heat Island (UHI) phenomenon. In an urban centre, maximum temperatures may be up to 10° C warmer, due to different local atmospheric conditions. UHI occurs in the metropolitan areas as function of the population size and density of a city. It consists of a significant difference in temperature compared to the rural/suburban areas. Increasing industrialization and urbanization have increased this phenomenon and it has recently also been detected in small cities. Weather conditions and land use are one of the key parameters in the formation of UHI. In particular surface urban heat island is directly related to temperatures, to land surface types and surface modifications. The present study concern a UHI analysis of Matera city (Italy) based on the analysis of temperature, change in land use and land cover, using Corine Land Cover maps and satellite Landsat images. Matera, located in Southern Italy, has a typical Mediterranean climate with mild winters and hot and humid summers. Moreover, Matera has been awarded the international title of the 2019 European Capital of Culture. Matera represents a significant example of vernacular architecture. The structure of the city is articulated by a vertical succession of dug layers sometimes excavated or partly excavated and partly built, according to the original shape and height of the calcarenitic slope. In this study, two meteorological stations were selected: MTA (MaTera Alsia, in industrial zone) and MTCP (MaTera Civil Protection, suburban area located in a green zone). In order to evaluate the increase in temperatures (in terms of UHI occurrences) over time, and evaluating the effect of land use on weather conditions, the climate variability of temperatures for both stations was explored. Results show that UHI phenomena is growing in Matera city, with an increase of maximum temperature values at a local scale. Subsequently, spatial analysis was conducted by Landsat satellite images. Four years was selected in the summer period (27/08/2000, 27/07/2006, 11/07/2012, 02/08/2017). In Particular, Landsat 7 ETM+ for 2000, 2006 and 2012 years; Landsat 8 OLI/TIRS for 2017. In order to estimate the LST, Mono Window Algorithm was applied. Therefore, the increase of LST values spatial scale trend has been verified, in according to results obtained at local scale. Finally, the analysis of land use maps over the years by the LST and/or the maximum temperatures measured, show that the development of industrialized area produces a corresponding increase in temperatures and consequently a growth in UHI.

Keywords: climate variability, land surface temperature, LANDSAT images, urban heat island

Procedia PDF Downloads 98
274 Primary-Color Emitting Photon Energy Storage Nanophosphors for Developing High Contrast Latent Fingerprints

Authors: G. Swati, D. Haranath

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Commercially available long afterglow /persistent phosphors are proprietary materials and hence the exact composition and phase responsible for their luminescent characteristics such as initial intensity and afterglow luminescence time are not known. Further to generate various emission colors, commercially available persistence phosphors are physically blended with fluorescent organic dyes such as rodhamine, kiton and methylene blue etc. Blending phosphors with organic dyes results into complete color coverage in visible spectra, however with time, such phosphors undergo thermal and photo-bleaching. This results in the loss of their true emission color. Hence, the current work is dedicated studies on inorganic based thermally and chemically stable primary color emitting nanophosphors namely SrAl2O4:Eu2+, Dy3+, (CaZn)TiO3:Pr3+, and Sr2MgSi2O7:Eu2+, Dy3+. SrAl2O4: Eu2+, Dy3+ phosphor exhibits a strong excitation in UV and visible region (280-470 nm) with a broad emission peak centered at 514 nm is the characteristic emission of parity allowed 4f65d1→4f7 transitions of Eu2+ (8S7/2→2D5/2). Sunlight excitable Sr2MgSi2O7:Eu2+,Dy3+ nanophosphors emits blue color (464 nm) with Commercial international de I’Eclairage (CIE) coordinates to be (0.15, 0.13) with a color purity of 74 % with afterglow time of > 5 hours for dark adapted human eyes. (CaZn)TiO3:Pr3+ phosphor system possess high color purity (98%) which emits intense, stable and narrow red emission at 612 nm due intra 4f transitions (1D2 → 3H4) with afterglow time of 0.5 hour. Unusual property of persistence luminescence of these nanophoshphors supersedes background effects without losing sensitive information these nanophosphors offer several advantages of visible light excitation, negligible substrate interference, high contrast bifurcation of ridge pattern, non-toxic nature revealing finger ridge details of the fingerprints. Both level 1 and level 2 features from a fingerprint can be studied which are useful for used classification, indexing, comparison and personal identification. facile methodology to extract high contrast fingerprints on non-porous and porous substrates using a chemically inert, visible light excitable, and nanosized phosphorescent label in the dark has been presented. The chemistry of non-covalent physisorption interaction between the long afterglow phosphor powder and sweat residue in fingerprints has been discussed in detail. Real-time fingerprint development on porous and non-porous substrates has also been performed. To conclude, apart from conventional dark vision applications, as prepared primary color emitting afterglow phosphors are potentional candidate for developing high contrast latent fingerprints.

Keywords: fingerprints, luminescence, persistent phosphors, rare earth

Procedia PDF Downloads 182
273 Virulence Factors and Drug Resistance of Enterococci Species Isolated from the Intensive Care Units of Assiut University Hospitals, Egypt

Authors: Nahla Elsherbiny, Ahmed Ahmed, Hamada Mohammed, Mohamed Ali

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Background: The enterococci may be considered as opportunistic agents particularly in immunocompromised patients. It is one of the top three pathogens causing many healthcare associated infections (HAIs). Resistance to several commonly used antimicrobial agents is a remarkable characteristic of most species which may carry various genes contributing to virulence. Objectives: to determine the prevalence of enterococci species in different intensive care units (ICUs) causing health care-associated infections (HAIs), intestinal carriage and environmental contamination. Also, to study the antimicrobial susceptibility pattern of the isolates with special reference to vancomycin resistance. In addition to phenotypic and genotypic detection of gelatinase, cytolysin and biofilm formation among isolates. Patients and Methods: This study was carried out in the infection control laboratory at Assiut University Hospitals over a period of one year. Clinical samples were collected from 285 patients with various (HAIs) acquired after admission to different ICUs. Rectal swabs were taken from 14 cases for detection of enterococci carriage. In addition, 1377 environmental samples were collected from the surroundings of the patients. Identification was done by conventional bacteriological methods and confirmed by analytical profile index (API). Antimicrobial sensitivity testing was performed by Kirby Bauer disc diffusion method and detection of vancomycin resistance was done by agar screen method. For the isolates, phenotypic detection of cytolysin, gelatinase production and detection of biofilm by tube method, Congo red method and microtiter plate. We performed polymerase chain reaction (PCR) for detection of some virulence genes (gelE, cylA, vanA, vanB and esp). Results: Enterococci caused 10.5% of the HAIs. Respiratory tract infection was the predominant type (86.7%). The commonest species were E.gallinarum (36.7%), E.casseliflavus (30%), E.faecalis (30%), and E.durans (3.4 %). Vancomycin resistance was detected in a total of 40% (12/30) of those isolates. The risk factors associated with acquiring vancomycin resistant enterococci (VRE) were immune suppression (P= 0.031) and artificial feeding (P= 0.008). For the rectal swabs, enterococci species were detected in 71.4% of samples with the predominance of E. casseliflavus (50%). Most of the isolates were vancomycin resistant (70%). Out of a total 1377 environmental samples, 577 (42%) samples were contaminated with different microorganisms. Enterococci were detected in 1.7% (10/577) of total contaminated samples, 50% of which were vancomycin resistant. All isolates were resistant to penicillin, ampicillin, oxacillin, ciprofloxacin, amikacin, erythromycin, clindamycin and trimethoprim-sulfamethaxazole. For the remaining antibiotics, variable percentages of resistance were reported. Cytolysin and gelatinase were detected phenotypically in 16% and 48 % of the isolates respectively. The microtiter plate method showed the highest percentages of detection of biofilm among all isolated species (100%). The studied virulence genes gelE, esp, vanA and vanB were detected in 62%, 12%, 2% and 12% respectively, while cylA gene was not detected in any isolates. Conclusions: A significant percentage of enterococci was isolated from patients and environments in the ICUs. Many virulence factors were detected phenotypically and genotypically among isolates. The high percentage of resistance, coupled with the risk of cross transmission to other patients make enterococci infections a significant infection control issue in hospitals.

Keywords: antimicrobial resistance, enterococci, ICUs, virulence factors

Procedia PDF Downloads 260
272 Phage Therapy of Staphylococcal Pyoderma in Dogs

Authors: Jiri Nepereny, Vladimir Vrzal

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Staphylococcus intermedius/pseudintermedius bacteria are commonly found on the skin of healthy dogs and can cause pruritic skin diseases under certain circumstances (trauma, allergy, immunodeficiency, ectoparasitosis, endocrinological diseases, glucocorticoid therapy, etc.). These can develop into complicated superficial or deep pyoderma, which represent a large group of problematic skin diseases in dogs. These are predominantly inflammations of a secondary nature, associated with the occurrence of coagulase-positive Staphylococcus spp. A major problem is increased itching, which greatly complicates the healing process. The aim of this work is to verify the efficacy of the developed preparation Bacteriophage SI (Staphylococcus intermedius). The tested preparation contains a lysate of bacterial cells of S. intermedius host culture including culture medium and live virions of specific phage. Sodium Merthiolate is added as a preservative in a safe concentration. Validation of the efficacy of the product was demonstrated by monitoring the therapeutic effect after application to indicated cases from clinical practice. The indication for inclusion of the patient into the trial was an adequate history and clinical examination accompanied by sample collection for bacteriological examination and isolation of the specific causative agent. Isolate identification was performed by API BioMérieux identification system (API ID 32 STAPH) and rep-PCR typing. The suitability of therapy for a specific case was confirmed by in vitro testing of the lytic ability of the bacteriophage to lyse the specific isolate = formation of specific plaques on the culture isolate on the surface of the solid culture medium. So far, a total of 32 dogs of different sexes, ages and breed affiliations with different symptoms of staphylococcal dermatitis have been included in the testing. Their previous therapy consisted of more or less successful systemic or local application of broad-spectrum antibiotics. The presence of S. intermedius/pseudintermedius has been demonstrated in 26 cases. The isolates were identified as a S. pseudintermedius, in all cases. Contaminant bacterial microflora was always present in the examined samples. The test product was applied subcutaneously in gradually increasing doses over a period of 1 month. After improvement in health status, maintenance therapy was followed by application of the product once a week for 3 months. Adverse effects associated with the administration of the product (swelling at the site of application) occurred in only 2 cases. In all cases, there was a significant reduction in clinical signs (healing of skin lesions and reduction of inflammation) after therapy and an improvement in the well-being of the treated animals. A major problem in the treatment of pyoderma is the frequent resistance of the causative agents to antibiotics, especially the increasing frequency of multidrug-resistant and methicillin-resistant S. pseudintermedius (MRSP) strains. Specific phagolysate using for the therapy of these diseases could solve this problem and to some extent replace or reduce the use of antibiotics, whose frequent and widespread application often leads to the emergence of resistance. The advantage of the therapeutic use of bacteriophages is their bactericidal effect, high specificity and safety. This work was supported by Project FV40213 from Ministry of Industry and Trade, Czech Republic.

Keywords: bacteriophage, pyoderma, staphylococcus spp, therapy

Procedia PDF Downloads 152
271 Identifying the Effects of the Rural Demographic Changes in the Northern Netherlands: A Holistic Approach to Create Healthier Environment

Authors: A. R. Shokoohi, E. A. M. Bulder, C. Th. van Alphen, D. F. den Hertog, E. J. Hin

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The Northern region of the Netherlands has beautiful landscapes, a nice diversity of green and blue areas, and dispersed settlements. However, some recent population changes can become threats to health and wellbeing in these areas. The rural areas in the three northern provinces -Groningen, Friesland, and Drenthe, see youngsters leave the region for which reason they are aging faster than other regions in the Netherlands. As a result, some villages have faced major population decline that is leading to loss of facilities/amenities and a decrease in accessibility and social cohesion. Those who still live in these villages are relatively old, low educated and have low-income. To develop a deeper understanding of the health status of the people living in these areas, and help them to improve their living environment, the GO!-Method is being applied in this study. This method has been developed by the National Institute for Public Health and the Environment (RIVM) of the Netherlands and is inspired by the broad definition of health by Machteld Huber: the ability to adapt and direct control, in terms of the physical, emotional and social challenges of life, while paying extra attention to vulnerable groups. A healthy living environment is defined as an environment that residents find it pleasant and encourages and supports healthy behavior. The GO!-method integrates six domains that constitute a healthy living environment: health and lifestyle, facilities and development, safety and hygiene, social cohesion and active citizens, green areas, and air and noise pollution. First of all, this method will identify opportunities for a healthier living environment using existing information and perceptions of residents and other local stakeholders in order to strengthen social participation and quality of life in these rural areas. Second, this approach will connect identified opportunities with available and effective evidence-based interventions in order to develop an action plan from the residents and local authorities perspective which will help them to design their municipalities healthier and more resilient. This method is being used for the first time in rural areas to our best knowledge, in close collaboration with the residents and local authorities of the three provinces to create a sustainable process and stimulate social participation. Our paper will present the outcomes of the first phase of this project in collaboration with the municipality of Westerkwartier, located in the northwest of the province of Groningen. And will describe the current situation, and identify local assets, opportunities, and policies relating to healthier environment; as well as needs and challenges to achieve goals. The preliminary results show that rural demographic changes in the northern Netherlands have negative impacts on service provisions and social cohesion, and there is a need to understand this complicated situation and improve the quality of life in those areas.

Keywords: population decline, rural areas, healthy environment, Netherlands

Procedia PDF Downloads 74
270 Effect of Ti, Nb, and Zr Additives on Biocompatibility of Injection Molded 316L Stainless Steel for Biomedical Applications

Authors: Busra Gundede, Ozal Mutlu, Nagihan Gulsoy

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Background: Over the years, material research has led to the development of numerous metals and alloys for using in biomedical applications. One of the major tasks of biomaterial research is the functionalization of the material surface to improve the biocompatibility according to a specific application. 316L and 316L alloys are excellent for various bio-applications. This research was investigated the effect of titanium (Ti), niobium (Nb), and zirconium (Zr) additives on injection molded austenitic grade 316L stainless steels in vitro biocompatibility. For this purpose, cytotoxic tests were performed to evaluate the potential biocompatibility of the specimens. Materials and Methods: 3T3 fibroblast were cultivated in DMEM supplemented with 10% fetal bovine serum and %1 penicillin-streptomycin at 37°C with 5% CO2 and 95%humidity. Trypsin/EDTA solution was used to remove cells from the culture flask. Cells were reseeded at a density of 1×105cell in 25T flasks. The medium change took place every 3 days. The trypan blue assay was used to determine cell viability. Cell viability is calculated as the number of viable cells divided by the total number of cells within the grids on the cell counter machine counted the number of blue staining cells and the number of total cells. Cell viability should be at least 95% for healthy log-phase cultures. MTT assay was assessed for 96-hours. Cells were cultivated in 6-well flask within 5 ml DMEM and incubated as same conditions. 0,5mg/ml MTT was added for 4-hours and then acid-isoprohanol was added for solubilize to formazan crystals. Cell morphology after 96h was investigated by SEM. The medium was removed, samples were washed with 0.15 M PBS buffer and fixed for 12h at 4- 8°C with %2,5 gluteraldehyte. Samples were treated with 1% osmium tetroxide. Samples were then dehydrated and dried, mounted on appropriate stubs with colloidal silver and sputter-coated with gold. Images were collected using a scanning electron microscope. ROS assay is a cell viability test for in vitro studies. Cells were grown for 96h, ROS solution added on cells in 6 well plate flask and incubated for 1h. Fluorescence signal indicates ROS generation by cells. Results: Trypan Blue exclusion assay results were 96%, 92%, 95%, 90%, 91% for negative control group, 316L, 316L-Ti, 316L-Nb and 316L-Zr, respectively. Results were found nearly similar to each other when compared with control group. Cell viability from MTT analysis was found to be 100%, 108%, 103%, 107%, and 105% for the control group, 316L, 316L-Ti, 316L-Nb and 316L-Zr, respectively. Fluorescence microscopy analysis indicated that all test groups were same as the control group in ROS assay. SEM images demonstrated that the attachment of 3T3 cells on biomaterials. Conclusion: We, therefore, concluded that Ti, Nb and Zr additives improved physical properties of 316L stainless. In our in vitro experiments showed that these new additives did not modify the cytocompatibility of stainless steel and these additives on 316L might be useful for biomedical applications.

Keywords: 316L stainles steel, biocompatibility, cell culture, Ti, Nb, Zr

Procedia PDF Downloads 490
269 An Integrated Approach to the Carbonate Reservoir Modeling: Case Study of the Eastern Siberia Field

Authors: Yana Snegireva

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Carbonate reservoirs are known for their heterogeneity, resulting from various geological processes such as diagenesis and fracturing. These complexities may cause great challenges in understanding fluid flow behavior and predicting the production performance of naturally fractured reservoirs. The investigation of carbonate reservoirs is crucial, as many petroleum reservoirs are naturally fractured, which can be difficult due to the complexity of their fracture networks. This can lead to geological uncertainties, which are important for global petroleum reserves. The problem outlines the key challenges in carbonate reservoir modeling, including the accurate representation of fractures and their connectivity, as well as capturing the impact of fractures on fluid flow and production. Traditional reservoir modeling techniques often oversimplify fracture networks, leading to inaccurate predictions. Therefore, there is a need for a modern approach that can capture the complexities of carbonate reservoirs and provide reliable predictions for effective reservoir management and production optimization. The modern approach to carbonate reservoir modeling involves the utilization of the hybrid fracture modeling approach, including the discrete fracture network (DFN) method and implicit fracture network, which offer enhanced accuracy and reliability in characterizing complex fracture systems within these reservoirs. This study focuses on the application of the hybrid method in the Nepsko-Botuobinskaya anticline of the Eastern Siberia field, aiming to prove the appropriateness of this method in these geological conditions. The DFN method is adopted to model the fracture network within the carbonate reservoir. This method considers fractures as discrete entities, capturing their geometry, orientation, and connectivity. But the method has significant disadvantages since the number of fractures in the field can be very high. Due to limitations in the amount of main memory, it is very difficult to represent these fractures explicitly. By integrating data from image logs (formation micro imager), core data, and fracture density logs, a discrete fracture network (DFN) model can be constructed to represent fracture characteristics for hydraulically relevant fractures. The results obtained from the DFN modeling approaches provide valuable insights into the East Siberia field's carbonate reservoir behavior. The DFN model accurately captures the fracture system, allowing for a better understanding of fluid flow pathways, connectivity, and potential production zones. The analysis of simulation results enables the identification of zones of increased fracturing and optimization opportunities for reservoir development with the potential application of enhanced oil recovery techniques, which were considered in further simulations on the dual porosity and dual permeability models. This approach considers fractures as separate, interconnected flow paths within the reservoir matrix, allowing for the characterization of dual-porosity media. The case study of the East Siberia field demonstrates the effectiveness of the hybrid model method in accurately representing fracture systems and predicting reservoir behavior. The findings from this study contribute to improved reservoir management and production optimization in carbonate reservoirs with the use of enhanced and improved oil recovery methods.

Keywords: carbonate reservoir, discrete fracture network, fracture modeling, dual porosity, enhanced oil recovery, implicit fracture model, hybrid fracture model

Procedia PDF Downloads 54
268 Assessing the Structure of Non-Verbal Semantic Knowledge: The Evaluation and First Results of the Hungarian Semantic Association Test

Authors: Alinka Molnár-Tóth, Tímea Tánczos, Regina Barna, Katalin Jakab, Péter Klivényi

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Supported by neuroscientific findings, the so-called Hub-and-Spoke model of the human semantic system is based on two subcomponents of semantic cognition, namely the semantic control process and semantic representation. Our semantic knowledge is multimodal in nature, as the knowledge system stored in relation to a conception is extensive and broad, while different aspects of the conception may be relevant depending on the purpose. The motivation of our research is to develop a new diagnostic measurement procedure based on the preservation of semantic representation, which is appropriate to the specificities of the Hungarian language and which can be used to compare the non-verbal semantic knowledge of healthy and aphasic persons. The development of the test will broaden the Hungarian clinical diagnostic toolkit, which will allow for more specific therapy planning. The sample of healthy persons (n=480) was determined by the last census data for the representativeness of the sample. Based on the concept of the Pyramids and Palm Tree Test, and according to the characteristics of the Hungarian language, we have elaborated a test based on different types of semantic information, in which the subjects are presented with three pictures: they have to choose the one that best fits the target word above from the two lower options, based on the semantic relation defined. We have measured 5 types of semantic knowledge representations: associative relations, taxonomy, motional representations, concrete as well as abstract verbs. As the first step in our data analysis, we examined the normal distribution of our results, and since it was not normally distributed (p < 0.05), we used nonparametric statistics further into the analysis. Using descriptive statistics, we could determine the frequency of the correct and incorrect responses, and with this knowledge, we could later adjust and remove the items of questionable reliability. The reliability was tested using Cronbach’s α, and it can be safely said that all the results were in an acceptable range of reliability (α = 0.6-0.8). We then tested for the potential gender differences using the Mann Whitney-U test, however, we found no difference between the two (p < 0.05). Likewise, we didn’t see that the age had any effect on the results using one-way ANOVA (p < 0.05), however, the level of education did influence the results (p > 0.05). The relationships between the subtests were observed by the nonparametric Spearman’s rho correlation matrix, showing statistically significant correlation between the subtests (p > 0.05), signifying a linear relationship between the measured semantic functions. A margin of error of 5% was used in all cases. The research will contribute to the expansion of the clinical diagnostic toolkit and will be relevant for the individualised therapeutic design of treatment procedures. The use of a non-verbal test procedure will allow an early assessment of the most severe language conditions, which is a priority in the differential diagnosis. The measurement of reaction time is expected to advance prodrome research, as the tests can be easily conducted in the subclinical phase.

Keywords: communication disorders, diagnostic toolkit, neurorehabilitation, semantic knowlegde

Procedia PDF Downloads 75
267 Rotterdam in Transition: A Design Case for a Low-Carbon Transport Node in Lombardijen

Authors: Halina Veloso e Zarate, Manuela Triggianese

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The urban challenges posed by rapid population growth, climate adaptation, and sustainable living have compelled Dutch cities to reimagine their built environment and transportation systems. As a pivotal contributor to CO₂ emissions, the transportation sector in the Netherlands demands innovative solutions for transitioning to low-carbon mobility. This study investigates the potential of transit oriented development (TOD) as a strategy for achieving carbon reduction and sustainable urban transformation. Focusing on the Lombardijen station area in Rotterdam, which is targeted for significant densification, this paper presents a design-oriented exploration of a low-carbon transport node. By employing a research-by-design methodology, this study delves into multifaceted factors and scales, aiming to propose future scenarios for Lombardijen. Drawing from a synthesis of existing literature, applied research, and practical insights, a robust design framework emerges. To inform this framework, governmental data concerning the built environment and material embodied carbon are harnessed. However, the restricted access to crucial datasets, such as property ownership information from the cadastre and embodied carbon data from De Nationale Milieudatabase, underscores the need for improved data accessibility, especially during the concept design phase. The findings of this research contribute fundamental insights not only to the Lombardijen case but also to TOD studies across Rotterdam's 13 nodes and similar global contexts. Spatial data related to property ownership facilitated the identification of potential densification sites, underscoring its importance for informed urban design decisions. Additionally, the paper highlights the disparity between the essential role of embodied carbon data in environmental assessments for building permits and its limited accessibility due to proprietary barriers. Although this study lays the groundwork for sustainable urbanization through TOD-based design, it acknowledges an area of future research worthy of exploration: the socio-economic dimension. Given the complex socio-economic challenges inherent in the Lombardijen area, extending beyond spatial constraints, a comprehensive approach demands integration of mobility infrastructure expansion, land-use diversification, programmatic enhancements, and climate adaptation. While the paper adopts a TOD lens, it refrains from an in-depth examination of issues concerning equity and inclusivity, opening doors for subsequent research to address these aspects crucial for holistic urban development.

Keywords: Rotterdam zuid, transport oriented development, carbon emissions, low-carbon design, cross-scale design, data-supported design

Procedia PDF Downloads 51
266 The Effect of the Precursor Powder Size on the Electrical and Sensor Characteristics of Fully Stabilized Zirconia-Based Solid Electrolytes

Authors: Olga Yu Kurapova, Alexander V. Shorokhov, Vladimir G. Konakov

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Nowadays, due to their exceptional anion conductivity at high temperatures cubic zirconia solid solutions, stabilized by rare-earth and alkaline-earth metal oxides, are widely used as a solid electrolyte (SE) materials in different electrochemical devices such as gas sensors, oxygen pumps, solid oxide fuel cells (SOFC), etc. Nowadays the intensive studies are carried out in a field of novel fully stabilized zirconia based SE development. The use of precursor powders for SE manufacturing allows predetermining the microstructure, electrical and sensor characteristics of zirconia based ceramics used as SE. Thus the goal of the present work was the investigation of the effect of precursor powder size on the electrical and sensor characteristics of fully stabilized zirconia-based solid electrolytes with compositions of 0,08Y2O3∙0,92ZrO2 (YSZ), 0,06Ce2O3∙ 0,06Y2O3∙0,88ZrO2 and 0,09Ce2O3∙0,06Y2O3-0,85ZrO2. The synthesis of precursors powders with different mean particle size was performed by sol-gel synthesis in the form of reversed co-precipitation from aqueous solutions. The cakes were washed until the neutral pH and pan-dried at 110 °С. Also, YSZ ceramics was obtained by conventional solid state synthesis including milling into a planetary mill. Then the powder was cold pressed into the pellets with a diameter of 7.2 and ~4 mm thickness at P ~16 kg/cm2 and then hydrostatically pressed. The pellets were annealed at 1600 °С for 2 hours. The phase composition of as-synthesized SE was investigated by X-Ray photoelectron spectroscopy ESCA (spectrometer ESCA-5400, PHI) X-ray diffraction analysis - XRD (Shimadzu XRD-6000). Following galvanic cell О2 (РО2(1)), Pt | SE | Pt, (РО2(2) = 0.21 atm) was used for SE sensor properties investigation. The value of РО2(1) was set by mixing of O2 and N2 in the defined proportions with the accuracy of  5%. The temperature was measured by Pt/Pt-10% Rh thermocouple, The cell electromotive force (EMF) measurement was carried out with ± 0.1 mV accuracy. During the operation at the constant temperature, reproducibility was better than 5 mV. Asymmetric potential measured for all SE appeared to be negligible. It was shown that the resistivity of YSZ ceramics decreases in about two times upon the mean agglomerates decrease from 200-250 to 40 nm. It is likely due to the both surface and bulk resistivity decrease in grains. So the overall decrease of grain size in ceramic SE results in the significant decrease of the total ceramics resistivity allowing sensor operation at lower temperatures. For the SE manufactured the estimation of oxygen ion transfer number tion was carried out in the range 600-800 °С. YSZ ceramics manufactured from powders with the mean particle size 40-140 nm, shows the highest values i.e. 0.97-0.98. SE manufactured from precursors with the mean particle size 40-140 nm shows higher sensor characteristic i.e. temperature and oxygen concentration EMF dependencies, EMF (ENernst - Ereal), tion, response time, then ceramics, manufactured by conventional solid state synthesis.

Keywords: oxygen sensors, precursor powders, sol-gel synthesis, stabilized zirconia ceramics

Procedia PDF Downloads 255
265 Study on Electromagnetic Plasma Acceleration Using Rotating Magnetic Field Scheme

Authors: Takeru Furuawa, Kohei Takizawa, Daisuke Kuwahara, Shunjiro Shinohara

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In the field of a space propulsion, an electric propulsion system has been developed because its fuel efficiency is much higher than a conventional chemical one. However, the practical electric propulsion systems, e.g., an ion engine, have a problem of short lifetime due to a damage of generation and acceleration electrodes of the plasma. A helicon plasma thruster is proposed as a long-lifetime electric thruster which has non-direct contact electrodes. In this system, both generation and acceleration methods of a dense plasma are executed by antennas from the outside of a discharge tube. Development of the helicon plasma thruster has been conducting under the Helicon Electrodeless Advanced Thruster (HEAT) project. Our helicon plasma thruster has two important processes. First, we generate a dense source plasma using a helicon wave with an excitation frequency between an ion and an electron cyclotron frequencies, fci and fce, respectively, applied from the outside of a discharge using a radio frequency (RF) antenna. The helicon plasma source can provide a high-density (~1019 m-3), a high-ionization ratio (up to several tens of percent), and a high particle generation efficiency. Second, in order to achieve high thrust and specific impulse, we accelerate the dense plasma by the axial Lorentz force fz using the product of the induced azimuthal current jθ and the static radial magnetic field Br, shown as fz = jθ × Br. The HEAT project has proposed several kinds of electrodeless acceleration schemes, and in our particular case, a Rotating Magnetic Field (RMF) method has been extensively studied. The RMF scheme was originally developed as a concept to maintain the Field Reversed Configuration (FRC) in a magnetically confined fusion research. Here, RMF coils are expected to generate jθ due to a nonlinear effect shown below. First, the rotating magnetic field Bω is generated by two pairs of RMF coils with AC currents, which have a phase difference of 90 degrees between the pairs. Due to the Faraday’s law, an axial electric field is induced. Second, an axial current is generated by the effects of an electron-ion and an electron-neutral collisions through the Ohm’s law. Third, the azimuthal electric field is generated by the nonlinear term, and the retarding torque generated by the collision effects again. Then, azimuthal current jθ is generated as jθ = - nₑ er ∙ 2π fRMF. Finally, the axial Lorentz force fz for plasma acceleration is generated. Here, jθ is proportional to nₑ and frequency of RMF coil current fRMF, when Bω is fully penetrated into the plasma. Our previous study has achieved 19 % increase of ion velocity using the 5 MHz and 50 A of the RMF coil power supply. In this presentation, we will show the improvement of the ion velocity using the lower frequency and higher current supplied by RMF power supply. In conclusion, helicon high-density plasma production and electromagnetic acceleration by the RMF scheme with a concept of electrodeless condition have been successfully executed.

Keywords: electric propulsion, electrodeless thruster, helicon plasma, rotating magnetic field

Procedia PDF Downloads 238
264 Processing of Flexible Dielectric Nanocomposites Using Nanocellulose and Recycled Alum Sludge for Wearable Technology Applications

Authors: D. Sun, L. Saw, A. Onyianta, D. O’Rourke, Z. Lu, C. See, C. Wilson, C. Popescu, M. Dorris

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With the rapid development of wearable technology (e.g., smartwatch, activity trackers and health monitor devices), flexible dielectric materials with environmental-friendly, low-cost and high-energy efficiency characteristics are in increasing demand. In this work, a flexible dielectric nanocomposite was processed by incorporating two components: cellulose nanofibrils and alum sludge in a polymer matrix. The two components were used in the reinforcement phase as well as for enhancing the dielectric properties; they were processed using waste materials that would otherwise be disposed to landfills. Alum sludge is a by-product of the water treatment process in which aluminum sulfate is prevalently used as the primary coagulant. According to the data from a project partner-Scottish Water: there are approximately 10k tons of alum sludge generated as a waste from the water treatment work to be landfilled every year in Scotland. The industry has been facing escalating financial and environmental pressure to develop more sustainable strategies to deal with alum sludge wastes. In the available literature, some work on reusing alum sludge has been reported (e.g., aluminum recovery or agriculture and land reclamation). However, little work can be found in applying it to processing energy materials (e.g., dielectrics) for enhanced energy density and efficiency. The alum sludge was collected directly from a water treatment plant of Scottish Water and heat-treated and refined before being used in preparing composites. Cellulose nanofibrils were derived from water hyacinth, an invasive aquatic weed that causes significant ecological issues in tropical regions. The harvested water hyacinth was dried and processed using a cost-effective method, including a chemical extraction followed by a homogenization process in order to extract cellulose nanofibrils. Biodegradable elastomer polydimethylsiloxane (PDMS) was used as the polymer matrix and the nanocomposites were processed by casting raw materials in Petri dishes. The processed composites were characterized using various methods, including scanning electron microscopy (SEM), rheological analysis, thermogravimetric and X-ray diffraction analysis. The SEM result showed that cellulose nanofibrils of approximately 20nm in diameter and 100nm in length were obtained and the alum sludge particles were of approximately 200um in diameters. The TGA/DSC analysis result showed that a weight loss of up to 48% can be seen in the raw material of alum sludge and its crystallization process has been started at approximately 800°C. This observation coincides with the XRD result. Other experiments also showed that the composites exhibit comprehensive mechanical and dielectric performances. This work depicts that it is a sustainable practice of reusing such waste materials in preparing flexible, lightweight and miniature dielectric materials for wearable technology applications.

Keywords: cellulose, biodegradable, sustainable, alum sludge, nanocomposite, wearable technology, dielectric

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263 Influence of Kneading Conditions on the Textural Properties of Alumina Catalysts Supports for Hydrotreating

Authors: Lucie Speyer, Vincent Lecocq, Séverine Humbert, Antoine Hugon

Abstract:

Mesoporous alumina is commonly used as a catalyst support for the hydrotreating of heavy petroleum cuts. The process of fabrication usually involves: the synthesis of the boehmite AlOOH precursor, a kneading-extrusion step, and a calcination in order to obtain the final alumina extrudates. Alumina is described as a complex porous medium, generally agglomerates constituted of aggregated nanocrystallites. Its porous texture directly influences the active phase deposition and mass transfer, and the catalytic properties. Then, it is easy to figure out that each step of the fabrication of the supports has a role on the building of their porous network, and has to be well understood to optimize the process. The synthesis of boehmite by precipitation of aluminum salts was extensively studied in the literature and the effect of various parameters, such as temperature or pH, are known to influence the size and shape of the crystallites and the specific surface area of the support. The calcination step, through the topotactic transition from boehmite to alumina, determines the final properties of the support and can tune the surface area, pore volume and pore diameters from those of boehmite. However, the kneading extrusion step has been subject to a very few studies. It generally consists in two steps: an acid, then a basic kneading, where the boehmite powder is introduced in a mixer and successively added with an acid and a base solution to form an extrudable paste. During the acid kneading, the induced positive charges on the hydroxyl surface groups of boehmite create an electrostatic repulsion which tends to separate the aggregates and even, following the conditions, the crystallites. The basic kneading, by reducing the surface charges, leads to a flocculation phenomenon and can control the reforming of the overall structure. The separation and reassembling of the particles constituting the boehmite paste have a quite obvious influence on the textural properties of the material. In this work, we are focused on the influence of the kneading step on the alumina catalysts supports. Starting from an industrial boehmite, extrudates are prepared using various kneading conditions. The samples are studied by nitrogen physisorption in order to analyze the evolution of the textural properties, and by synchrotron small-angle X-ray scattering (SAXS), a more original method which brings information about agglomeration and aggregation of the samples. The coupling of physisorption and SAXS enables a precise description of the samples, as same as an accurate monitoring of their evolution as a function of the kneading conditions. These ones are found to have a strong influence of the pore volume and pore size distribution of the supports. A mechanism of evolution of the texture during the kneading step is proposed and could be attractive in order to optimize the texture of the supports and then, their catalytic performances.

Keywords: alumina catalyst support, kneading, nitrogen physisorption, small-angle X-ray scattering

Procedia PDF Downloads 233
262 'Utsadhara': Rejuvenating the Dead River Edge into an Urban Activity Space along the Banks of River Hooghly

Authors: Aparna Saha, Tuhin Ahmed

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West Bengal has a number of important rivers, each with its distinctive character and a story. Traditionally, cities have ‘divulged’ to rivers at the river edges and rivers have been an inseparable part of the urban experience. Considering the research aspect, the area is taken in Barrackpore, a small but important outgrowth of Kolkata Municipal Association, West Bengal. Barrackpore, at present, has ample inadequate public open spaces at the neighborhood level where people of different socio-cultural, economic, and religious backgrounds can come together and engage in various leisure activities, but there is no opportunity either, where people can learn about and explore the rich history of the settlement. Pertaining to these issues forms the backdrop of this research paper which has been conceptualized as a place from space that will bring people back to the river and increase community interactions and will also celebrate and commemorate towards the historical importance of the river and its edges. The entire precinct bordering the river represents the transition from pre-independence (Raj era) to Sepoy phase (Swaraj era), finally culminating into the Gandhian philosophy which is being projected into the already existing Gandhi Ghat. The ultimate aim of the paper entitled ‘Utsadhara- Rejuvenating the dead river edge into an urban activity space along the banks of river Hooghly’ is to create a socio-cultural space keeping the heritage identity intact through judicious use of the water body. Also, a balance is kept between the natural ecosystem and the cosmetic development of the surrounding open spaces. It can be duly achieved by the aforementioned methodology provided in the document, but mainly it would focus into preserving the historic ethnicity of the place by holding its character through various facts and figures as well as features. Most importantly the natural topography of the place is left intact. The second priority is given in terms of hierarchy of well connected public plazas, podiums where people from different socio-economic backgrounds irrespective of age and sex could socialize and reach towards venturing into a cordial relationship with one another. The third priority is to provide a platform for the common mass for showcasing their skills and talent through different art and craft forms which in turn would enhance their individual self and also the community as a whole through economic rise. Apart from this here some spaces are created in accordance to different age groups or class of people. The paper intends to see the river as a major multifunctional public space to attract people for different activities and re-establish the relationship of the river with the settlement. Hence, it is apprehended that the paper is not only intended to a simple riverfront conservation project but unlike others it is a place which is created for the people, by the people and of the people towards a holistic community development through a sustainable approach.

Keywords: holistic community development, public activity space, river-urban precinct, urban dead space

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261 Design Approach to Incorporate Unique Performance Characteristics of Special Concrete

Authors: Devendra Kumar Pandey, Debabrata Chakraborty

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The advancement in various concrete ingredients like plasticizers, additives and fibers, etc. has enabled concrete technologists to develop many viable varieties of special concretes in recent decades. Such various varieties of concrete have significant enhancement in green as well as hardened properties of concrete. A prudent selection of appropriate type of concrete can resolve many design and application issues in construction projects. This paper focuses on usage of self-compacting concrete, high early strength concrete, structural lightweight concrete, fiber reinforced concrete, high performance concrete and ultra-high strength concrete in the structures. The modified properties of strength at various ages, flowability, porosity, equilibrium density, flexural strength, elasticity, permeability etc. need to be carefully studied and incorporated into the design of the structures. The paper demonstrates various mixture combinations and the concrete properties that can be leveraged. The selection of such products based on the end use of structures has been proposed in order to efficiently utilize the modified characteristics of these concrete varieties. The study involves mapping the characteristics with benefits and savings for the structure from design perspective. Self-compacting concrete in the structure is characterized by high shuttering loads, better finish, and feasibility of closer reinforcement spacing. The structural design procedures can be modified to specify higher formwork strength, height of vertical members, cover reduction and increased ductility. The transverse reinforcement can be spaced at closer intervals compared to regular structural concrete. It allows structural lightweight concrete structures to be designed for reduced dead load, increased insulation properties. Member dimensions and steel requirement can be reduced proportionate to about 25 to 35 percent reduction in the dead load due to self-weight of concrete. Steel fiber reinforced concrete can be used to design grade slabs without primary reinforcement because of 70 to 100 percent higher tensile strength. The design procedures incorporate reduction in thickness and joint spacing. High performance concrete employs increase in the life of the structures by improvement in paste characteristics and durability by incorporating supplementary cementitious materials. Often, these are also designed for slower heat generation in the initial phase of hydration. The structural designer can incorporate the slow development of strength in the design and specify 56 or 90 days strength requirement. For designing high rise building structures, creep and elasticity properties of such concrete also need to be considered. Lastly, certain structures require a performance under loading conditions much earlier than final maturity of concrete. High early strength concrete has been designed to cater to a variety of usages at various ages as early as 8 to 12 hours. Therefore, an understanding of concrete performance specifications for special concrete is a definite door towards a superior structural design approach.

Keywords: high performance concrete, special concrete, structural design, structural lightweight concrete

Procedia PDF Downloads 284
260 Influence of Cryo-Grinding on Antioxidant Activity and Amount of Free Phenolic Acids, Rutin and Tyrosol in Whole Grain Buckwheat and Pumpkin Seed Cake

Authors: B. Voucko, M. Benkovic, N. Cukelj, S. Drakula, D. Novotni, S. Balbino, D. Curic

Abstract:

Oxidative stress is considered as one of the causes leading to metabolic disorders in humans. Therefore, the ability of antioxidants to inhibit free radical production is their primary role in the human organism. Antioxidants originating from cereals, especially flavonoids and polyphenols, are mostly bound and indigestible. Micronization damages the cell wall which consecutively results in bioactive material to be more accessible in vivo. In order to ensure complete fragmentation, micronization is often combined with high temperatures (e.g., for bran 200°C) which can lead to degradation of bioactive compounds. The innovative non-thermal technology of cryo-milling is an ultra-fine micronization method that uses liquid nitrogen (LN2) at a temperature of 195°C to freeze and cool the sample during milling. Freezing at such low temperatures causes the material to become brittle which ensures the generation of fine particles while preserving the bioactive content of the material. The aim of this research was to determine if production of ultra-fine material with cryo-milling will result in the augmentation of available bioactive compounds of buckwheat and pumpkin seed cake. For that reason, buckwheat and pumpkin seed cake were ground in a ball mill (CryoMill, Retch, Germany) with and without the use of LN2 for 8 minutes, in a 50 mL stainless steel jar containing one grinding ball (Ø 25 mm) at an oscillation frequency of 30 Hz. The cryo-milled samples were cooled with LN2 for 2 minutes prior to milling, followed by the first cycle of milling (4 minutes), intermediary cooling (2 minutes), and finally the second cycle of milling (further 4 minutes). A continuous process of milling was applied to the samples ground without freezing with LN2. Particle size distribution was determined using the Scirocco 2000 dry dispersion unit (Malvern Instruments, UK). Antioxidant activity was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) test and ferric reducing antioxidant power (FRAP) assay, while the total phenol content was determined using the Folin Ciocalteu method, using the ultraviolet-visible spectrophotometer (Specord 50 Plus, Germany). The content of the free phenolic acids, rutin in buckwheat, tyrosol in pumpkin seed cake, was determined with an HPLC-PDA method (Agilent 1200 series, Germany). Cryo-milling resulted in 11 times smaller size of buckwheat particles, and 3 times smaller size of pumpkin seed particles than milling without the use of LN2, but also, a lower uniformity of the particle size distribution. Lack of freezing during milling of pumpkin seed cake caused a formation of agglomerates due to its high-fat content (21 %). Cryo-milling caused augmentation of buckwheat flour antioxidant activity measured by DPPH test (23,9%) and an increase in available rutin content (14,5%). Also, it resulted in an augmentation of the total phenol content (36,9%) and available tyrosol content (12,5%) of pumpkin seed cake. Antioxidant activity measured with the FRAP test, as well as the content of phenolic acids remained unchanged independent of the milling process. The results of this study showed the potential of cryo-milling for complete raw material utilization in the food industry, as well as a tool for extraction of aimed bioactive components.

Keywords: bioactive, ball-mill, buckwheat, cryo-milling, pumpkin seed cake

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259 Training for Safe Tree Felling in the Forest with Symmetrical Collaborative Virtual Reality

Authors: Irene Capecchi, Tommaso Borghini, Iacopo Bernetti

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One of the most common pieces of equipment still used today for pruning, felling, and processing trees is the chainsaw in forestry. However, chainsaw use highlights dangers and one of the highest rates of accidents in both professional and non-professional work. Felling is proportionally the most dangerous phase, both in severity and frequency, because of the risk of being hit by the plant the operator wants to cut down. To avoid this, a correct sequence of chainsaw cuts must be taught concerning the different conditions of the tree. Virtual reality (VR) makes it possible to virtually simulate chainsaw use without danger of injury. The limitations of the existing applications are as follow. The existing platforms are not symmetrical collaborative because the trainee is only in virtual reality, and the trainer can only see the virtual environment on a laptop or PC, and this results in an inefficient teacher-learner relationship. Therefore, most applications only involve the use of a virtual chainsaw, and the trainee thus cannot feel the real weight and inertia of a real chainsaw. Finally, existing applications simulate only a few cases of tree felling. The objectives of this research were to implement and test a symmetrical collaborative training application based on VR and mixed reality (MR) with the overlap between real and virtual chainsaws in MR. The research and training platform was developed for the Meta quest 2 head-mounted display. The research and training platform application is based on the Unity 3D engine, and Present Platform Interaction SDK (PPI-SDK) developed by Meta. PPI-SDK avoids the use of controllers and enables hand tracking and MR. With the combination of these two technologies, it was possible to overlay a virtual chainsaw with a real chainsaw in MR and synchronize their movements in VR. This ensures that the user feels the weight of the actual chainsaw, tightens the muscles, and performs the appropriate movements during the test allowing the user to learn the correct body posture. The chainsaw works only if the right sequence of cuts is made to felling the tree. Contact detection is done by Unity's physics system, which allows the interaction of objects that simulate real-world behavior. Each cut of the chainsaw is defined by a so-called collider, and the felling of the tree can only occur if the colliders are activated in the right order simulating a safe technique felling. In this way, the user can learn how to use the chainsaw safely. The system is also multiplayer, so the student and the instructor can experience VR together in a symmetrical and collaborative way. The platform simulates the following tree-felling situations with safe techniques: cutting the tree tilted forward, cutting the medium-sized tree tilted backward, cutting the large tree tilted backward, sectioning the trunk on the ground, and cutting branches. The application is being evaluated on a sample of university students through a special questionnaire. The results are expected to test both the increase in learning compared to a theoretical lecture and the immersive and telepresence of the platform.

Keywords: chainsaw, collaborative symmetric virtual reality, mixed reality, operator training

Procedia PDF Downloads 87
258 Children’s Experience of the Built Environment in the Initial Stages of a Settlement Formation: Case Study of Shahid-Keshvari New Settlement, Isfahan, Iran

Authors: Hassan Sheikh, Mehdi Nilipour, Amiraslan Fila

Abstract:

Many conventional town planning processes do little to give children and young people a voice on what is important about the urban environment. As a result of paying little attention to the children, their physical, social and mental needs are hardly met in urban environments. Therefore, urban spaces are impotent to attract children, while their recreational space has been confined to home or virtual spaces. Since children are just taking the first steps to learn the world beyond house borders, their living environment will profoundly influence almost all aspects of their lives. This puts a great deal of responsibility on the shoulders of planners, who need to balance a number of different issues in urban design to make places more child-friendly. The main purpose of present research is to analyze and plan a child-friendly environment in an on-going urban settlement development for the benefit of all residents. Assessing children’s needs and regard them in development strategies and policies will help to “plan for children”. Following this purpose, based on child-friendly environment studies, indicators of child-friendly environments were collected. Then three distinct characteristics of case study, which are being under-construction, lack of social ties between dwellers and high-rise building, determined seven indicators included basic services, Urban and environmental qualities, Family, kin, peers and community, Sense of belonging and continuity, participation, Safety, security and freedom of movement and human scale. With the survey, Informal observation and participation in small communities, essential data has been collected and analyzed by SPSS software. The field study is Shahid-Keshvari town in Isfahan, Iran. Eighty-six middle childhood, children (ages 8-13) participated. The results show Children's satisfaction is correlated with basic services and the quality of the environment, social environment and the safety and security. The considerable number of children and youth (55%) like to live somewhere other than the town. Satisfaction and sense of belonging and continuity have a strong inverse correlation with age. In other words, as age increases, satisfaction and consequently a sense of belonging will be reduced; thus children and youth consider their future somewhere out of the town. The main reason for dissatisfaction was the basic services and social environment. More than half of children (55%) expressed their wish to develop basic services in terms of availability, hierarchy, and quality. Among all recreational places, children showed more interest to the parks. About three-quarters (76%) considered building a park as a crucial item for residents. The significant number of children (54%) want to have a relationship with more friends. This could be due to the serious shortage of the leisure spaces such as parks or playgrounds. Also, the space around the house or space between the apartments has not been designed for play or children’s activities. Moreover, the presence of strangers and construction workers have a negative impact on children's sense of peace and security; 60% of children are afraid of theft and 36% of children found strangers as a menace. The analysis of children’s issues and suggestions provides an insight to plan and design of child-friendly environment in new towns.

Keywords: child-friendly city (CFC), child-friendly environment, child participation, under-construction environment, Isfahan Shahid-Keshvari Town

Procedia PDF Downloads 353