Search results for: exponential time differencing method

Authors: A. Dudek, P. Tylec, G. Torbicz, P. Duda, K. Proniewska, P. Major, M. Pedziwiatr

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Background: Conservative treatments of obesity, based only on a proper diet and physical activity, without the support of an interdisciplinary team of specialist does not bring satisfactory bariatric results. Long-term maintenance of a proper metabolic results after rapid weight loss due to bariatric surgery requires engagement from patients. Mobile health tool may offer alternative model that enhance participant engagement in keeping the therapy. Objective: We aimed to assess the influence of constant monitoring and subsequent motivational alerts in perioperative period and on post-operative effects in the bariatric patients. As well as the study was designed to identify factors conductive urge to change lifestyle after surgery. Methods: This prospective clinical control study was based on a usage of a designed prototype of bariatric mHealth system. The prepared application comprises central data management with a comprehensible interface dedicated for patients and data transfer module as a physician’s platform. Motivation system of a platform consist of motivational alerts, graphic outcome presentation, and patient communication center. Generated list of patients requiring urgent consultation and possibility of a constant contact with a specialist provide safety zone. 31 patients were enrolled in continuous monitoring program during a 6-month period along with typical follow-up visits. After one year follow-up, all patients were examined. Results: There were 20 active users of the proposed monitoring system during the entire duration of the study. After six months, 24 patients took a part in a control by telephone questionnaires. Among them, 75% confirmed that the application concept was an important element in the treatment. Active users of the application indicated as the most valuable features: motivation to continue treatment (11 users), graphical presentation of weight loss, and other parameters (7 users), the ability to contact a doctor (3 users). The three main drawbacks are technical errors (9 users), tedious questionnaires inside the application (5 users), and time-consuming tasks inside the system (2 users). Conclusions: Constant monitoring and successive motivational alerts to continue treatment is an appropriate tool in the treatment after bariatric surgery, mainly in the early post-operative period. Graphic presentation of data and continuous connection with a clinical staff seemed to be an element of motivation to continue treatment and a sense of security.

Keywords: bariatric surgery, mHealth, mobile health tool, obesity

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Authors: Antonina A. Shumakova, Sergey A. Khotimchenko

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The relevance of research is associated, on the one hand, with an ever-increasing volume of production and the expansion of the scope of application of engineered nanomaterials (ENMs), and on the other hand, with the lack of sufficient scientific information on the nature of the interactions of nanoparticles (NPs) with components of biogenic and abiogenic origin. In particular, studying the effect of ENMs (TiO2 NPs, SiO2 NPs, Al2O3 NPs, fullerenol) on the toxicometric characteristics of common contaminants such as lead and cadmium is an important hygienic task, given the high probability of their joint presence in food products. Data were obtained characterizing a multidirectional change in the toxicity of model toxicants when they are co-administered with various types of ENMs. One explanation for this fact is the difference in the adsorption capacity of ENMs, which was further studied in in vitro studies. For this, a method was proposed based on in vitro modeling of conditions simulating the environment of the small intestine. It should be noted that the obtained data are in good agreement with the results of in vivo experiments: - with the combined administration of lead and TiO2 NPs, there were no significant changes in the accumulation of lead in rat liver; in other organs (kidneys, spleen, testes and brain), the lead content was lower than in animals of the control group; - studying the combined effect of lead and Al2O3 NPs, a multiple and significant increase in the accumulation of lead in rat liver was observed with an increase in the dose of Al2O3 NPs. For other organs, the introduction of various doses of Al2O3 NPs did not significantly affect the bioaccumulation of lead; - with the combined administration of lead and SiO2 NPs in different doses, there was no increase in lead accumulation in all studied organs. Based on the data obtained, it can be assumed that at least three scenarios of the combined effects of ENMs and chemical contaminants on the body: - ENMs quite firmly bind contaminants in the gastrointestinal tract and such a complex becomes inaccessible (or inaccessible) for absorption; in this case, it can be expected that the toxicity of both ENMs and contaminants will decrease; - the complex formed in the gastrointestinal tract has partial solubility and can penetrate biological membranes and / or physiological barriers of the body; in this case, ENMs can play the role of a kind of conductor for contaminants and, thus, their penetration into the internal environment of the body increases, thereby increasing the toxicity of contaminants; - ENMs and contaminants do not interact with each other in any way, therefore the toxicity of each of them is determined only by its quantity and does not depend on the quantity of another component. Authors hypothesized that the degree of adsorption of various elements on the surface of ENMs may be a unique characteristic of their action, allowing a more accurate understanding of the processes occurring in a living organism.

Keywords: absorption, cadmium, engineered nanomaterials, lead

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Authors: Simon Grossemy, Peggy P. Y. Chan, Pauline M. Doran

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Nerve tissue engineering is the main field of research aimed at finding an alternative to autografts as a treatment for nerve injuries. Scaffolds are used as a support to enhance nerve regeneration. In order to successfully design novel scaffolds and in vitro cell culture systems, a deep understanding of the factors affecting nerve regeneration processes is needed. Physical and biological parameters associated with the culture environment have been identified as potentially influential in nerve cell differentiation, including electrical stimulation, exposure to extracellular-matrix (ECM) proteins, dynamic medium conditions and co-culture with glial cells. The mechanisms involved in driving the cell to differentiation in the presence of these factors are poorly understood; the complexity of each of them raises the possibility that they may strongly influence each other. Some questions that arise in investigating nerve regeneration include: What are the best protein coatings to promote neural cell attachment? Is the scaffold design suitable for providing all the required factors combined? What is the influence of dynamic stimulation on cell viability and differentiation? In order to study these effects, scaffolds adaptable to bioreactor culture conditions were designed to allow electrical stimulation of cells exposed to ECM proteins, all within a dynamic medium environment. Gold coatings were used to make the surface of viscose rayon microfiber scaffolds (VRMS) conductive, and poly-L-lysine (PLL) and laminin (LN) surface coatings were used to mimic the ECM environment and allow the attachment of rat PC12 neural cells. The robustness of the coatings was analyzed by surface resistivity measurements, scanning electron microscope (SEM) observation and immunocytochemistry. Cell attachment to protein coatings of PLL, LN and PLL+LN was studied using DNA quantification with Hoechst. The double coating of PLL+LN was selected based on high levels of PC12 cell attachment and the reported advantages of laminin for neural differentiation. The underlying gold coatings were shown to be biocompatible using cell proliferation and live/dead staining assays. Coatings exhibiting stable properties over time under dynamic fluid conditions were developed; indeed, cell attachment and the conductive power of the scaffolds were maintained over 2 weeks of bioreactor operation. These scaffolds are promising research tools for understanding complex neural cell behavior. They have been used to investigate major factors in the physical culture environment that affect nerve cell viability and differentiation, including electrical stimulation, bioreactor hydrodynamic conditions, and combinations of these parameters. The cell and tissue differentiation response was evaluated using DNA quantification, immunocytochemistry, RT-qPCR and functional analyses.

Keywords: bioreactor, electrical stimulation, nerve differentiation, PC12 cells, scaffold

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Authors: Ponghyung Lee

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This study seeks to investigate the variations occurring to Korean consonantal variations center around laryngeal features of the concerned sounds, to the exclusion of others. Our fundamental premise is that the weak contrast associated with concerned segments might be held accountable for the oscillation of the status quo of the concerned consonants. What is more, we assume that an array of notions as a measure of communicative efficiency of linguistic units would be significantly influential on triggering those variations. To this end, we have tried to compute the surprisal, entropic contribution, and relative contrastiveness associated with Korean obstruent consonants. What we found therein is that the Information-theoretic perspective is compelling enough to lend support our approach to a considerable extent. That is, the variant realizations, chronologically and stylistically, prove to be profoundly affected by a set of Information-theoretic factors enumerated above. When it comes to the biblical proper names, we use Georgetown University CQP Web-Bible corpora. From the 8 texts (4 from Old Testament and 4 from New Testament) among the total 64 texts, we extracted 199 samples. We address the issue of laryngeal feature variations associated with Korean obstruent consonants under the presumption that the variations stem from the weak contrast among the triad manifestations of laryngeal features. The variants emerge from diverse sources in chronological and stylistic senses: Christianity biblical texts, ordinary casual speech, the shift of loanword adaptation over time, and ideophones. For the purpose of discussing what they are really like from the perspective of Information Theory, it is necessary to closely look at the data. Among them, the massive changes occurring to loanword adaptation of proper nouns during the centennial history of Korean Christianity draw our special attention. We searched 199 types of initially capitalized words among 45,528-word tokens, which account for around 5% of total 901,701-word tokens (12,786-word types) from Georgetown University CQP Web-Bible corpora. We focus on the shift of the laryngeal features incorporated into word-initial consonants, which are available through the two distinct versions of Korean Bible: one came out in the 1960s for the Protestants, and the other was published in the 1990s for the Catholic Church. Of these proper names, we have closely traced the adaptation of plain obstruents, e. g. /b, d, g, s, ʤ/ in the sources. The results show that as much as 41% of the extracted proper names show variations; 37% in terms of aspiration, and 4% in terms of tensing. This study set out in an effort to shed light on the question: to what extent can we attribute the variations occurring to the laryngeal features associated with Korean obstruent consonants to the communicative aspects of linguistic activities? In this vein, the concerted effects of the triad, of surprisal, entropic contribution, and relative contrastiveness can be credited with the ups and downs in the feature specification, despite being contentiousness on the role of surprisal to some extent.

Keywords: entropic contribution, laryngeal feature variation, relative contrastiveness, surprisal

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Authors: George Hanna Abdelmelek Henien

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Quality and safety issues are common in Ethiopia's food processing industry, which can negatively impact consumers' health and livelihoods. The country is known for its various agricultural products that are important to the economy. However, food quality and safety policies and management practices in the food processing industry have led to many health problems, foodborne illnesses and economic losses. This article aims to show the causes and consequences of food safety and quality problems in the food processing industry in Ethiopia and discuss possible solutions to solve them. One of the main reasons for food quality and safety in Ethiopia's food processing industry is the lack of adequate regulation and enforcement mechanisms. Inadequate food safety and quality policies have led to inefficiencies in food production. Additionally, the failure to monitor and enforce existing regulations has created a good opportunity for unscrupulous companies to engage in harmful practices that endanger the lives of citizens. The impact on food quality and safety is significant due to loss of life, high medical costs, and loss of consumer confidence in the food processing industry. Foodborne diseases such as diarrhoea, typhoid and cholera are common in Ethiopia, and food quality and safety play an important role in . Additionally, food recalls due to contamination or contamination often cause significant economic losses in the food processing industry. To solve these problems, the Ethiopian government began taking measures to improve food quality and safety in the food processing industry. One of the most prominent initiatives is the Ethiopian Food and Drug Administration (EFDA), which was established in 2010 to monitor and control the quality and safety of food and beverage products in the country. EFDA has implemented many measures to improve food safety, such as carrying out routine inspections, monitoring the import of food products and implementing labeling requirements. Another solution that can improve food quality and safety in the food processing industry in Ethiopia is the implementation of food safety management system (FSMS). FSMS is a set of procedures and policies designed to identify, assess and control food safety risks during food processing. Implementing a FSMS can help companies in the food processing industry identify and address potential risks before they harm consumers. Additionally, implementing an FSMS can help companies comply with current safety and security regulations. Consequently, improving food safety policy and management system in Ethiopia's food processing industry is important to protect people's health and improve the country's economy. . Addressing the root causes of food quality and safety and implementing practical solutions that can help improve the overall food safety and quality in the country, such as establishing regulatory bodies and implementing food management systems.

Keywords: food quality, food safety, policy, management system, food processing industry food traceability, industry 4.0, internet of things, block chain, best worst method, marcos

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Authors: Birgit Rasmussen, Thomas Maribo, Bente S. Toft

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BACKGROUND: Cardiac rehabilitation is the standard treatment for ischemic heart disease. Cardiac rehabilitation improves quality of life, reduces mortality and the risk of readmission, and provides patients with valuable knowledge and encouragement from peers and staff. Still, less than half of eligible patients enroll. Face-to-face interventions have the potential to support patients' decision-making and increase enrolment in cardiac rehabilitation. However, we lack knowledge of the content and characteristics of interventions. AIM: The aim was to outline and evaluate the content and characteristics of studies that have reported on face-to-face interventions to encourage enrolment in cardiac rehabilitation in patients with ischemic heart disease. METHOD: This scoping review followed the Joanne Briggs Institute methodology. Based on an a-priori protocol that defined the systematic search criteria, six databases were searched for studies published between 2001 and 2023. Two reviewers independently screened and selected studies. All authors discussed the summarized data prior to the narrative presentation. RESULTS: After screening and full text review of 5583 records, 20 studies of heterogeneous design and content were included. Four studies described the key contents in face-to-face interventions to be education, support of autonomy, addressing reasons for change, and emotional and cognitive support while showing understanding. Two studies used motivational interviewing to target patients' experiences and address worries and anticipated difficulties. Four quantitative studies found associations between enrolment and intention to attend, cardiac rehabilitation barriers, exercise self-efficacy, and perceived control. When patients asked questions, enrolment rates were higher, while providing reassurance and optimism could lead to non-attendance if patients had a high degree of worry. In qualitative studies, support to overcome barriers and knowledge about health benefits from participation in cardiac rehabilitation facilitated enrolment. Feeling reassured that the cardiac condition was good could lead to non-attendance. DISCUSSION AND CONCLUSION: To support patients' enrolment in cardiac rehabilitation, it is recommended that interventions integrate a person-centered dialogue. Individual worries and barriers to cardiac rehabilitation should be jointly explored. When talking with patients for whom worries predominate, the recommendation is to focus on the patients' perspectives and avoid too much focus on reassurance and problem-solving. The patients' perspectives, the mechanisms of change, and the process evaluation of the intervention including person-centeredness are relevant to include in future studies.

Keywords: ischemic heart disease, cardiac rehabilitation, enrolment, person-centered, in-hospital interventions

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Authors: Sadao Araki, Daisuke Gondo, Satoshi Imasaka, Hideki Yamamoto

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The separation of organic compounds from aqueous solutions is a key technology for recycling valuable organic compounds and for the treatment of wastewater. The wastewater from chemical plants often contains organic compounds such as ethyl acetate (EA), methylethyl ketone (MEK) and isopropyl alcohol (IPA). In this study, we prepared hydrophobic silica membranes by a sol-gel method. We used phenyltrimethoxysilane (PhTMS), ethyltrimethoxysilan (ETMS), Propyltrimethoxysilane (PrTMS), N-butyltrimethoxysilane (BTMS), N-Hexyltrimethoxysilane (HTMS) as silica sources to introduce each functional groups on the membrane surface. Cetyltrimethyl ammonium bromide (CTAB) was used as a molecular template to create suitable pore that enable the permeation of organic compounds. These membranes with five different functional groups were characterized by SEM, FT-IR, and permporometry. Thicknesses and pore diameters of silica layer for all membrane were about 1.0 μm and about 1 nm, respectively. In other words, functional groups had an insignificant effect on the membrane thicknesses and the formation of the pore by CTAB. We confirmed the effect of functional groups on the flux and separation factor for ethyl acetate (EA), methyl ethyl ketone, acetone and 1-butanol (1-BtOH) /water mixtures. All membranes showed a high flux for ethyl acetate compared with other compounds. In particular, the hydrophobic silica membrane prepared by using BTMS showed 0.75 kg m-2 h-1 of flux for EA. For all membranes, the fluxes of organic compounds showed the large values in the order corresponding to EA > MEK > acetone > 1-BtOH. On the other hand, carbon chain length of functional groups among ETMS, PrTMS, BTMS, PrTMS and HTMS did not have a major effect on the organic flux. Although we confirmed the relationship between organic fluxes and organic molecular diameters or fugacity of organic compounds, these factors had a low correlation with organic fluxes. It is considered that these factors affect the diffusivity. Generally, permeation through membranes is based on the diffusivity and solubility. Therefore, it is deemed that organic fluxes through these hydrophobic membranes are strongly influenced by solubility. We tried to estimate the organic fluxes by Hansen solubility parameter (HSP). HSP, which is based on the cohesion energy per molar volume and is composed of dispersion forces (δd), intermolecular dipole interactions (δp), and hydrogen-bonding interactions (δh), has recently attracted attention as a means for evaluating the resolution and aggregation behavior. Evaluation of solubility for two substances can be represented by using the Ra [(MPa)1/2] value, meaning the distance of HSPs for both of substances. A smaller Ra value means a higher solubility for each substance. On the other hand, it can be estimated that the substances with large Ra value show low solubility. We established the correlation equation, which was based on Ra, of organic flux at low concentrations of organic compounds and at 295-325 K.

Keywords: hydrophobic, membrane, Hansen solubility parameter, functional group

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Authors: Thor Alexis Sazon, Alexander Guzman-Urbina, Yasuhiro Fukushima

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This study outlines the method of how to develop a surrogate life cycle model based on fuzzy logic using three fuzzy inference methods: (1) the conventional Fuzzy Inference System (FIS), (2) the hybrid system of Data Analytics and Fuzzy Inference (DAFIS), which uses data clustering for defining the membership functions, and (3) the Adaptive-Neuro Fuzzy Inference System (ANFIS), a combination of fuzzy inference and artificial neural network. These methods were demonstrated with a case study where the Global Warming Potential (GWP) and the Levelized Cost of Energy (LCOE) of solar photovoltaic (PV) were estimated using Solar Irradiation, Module Efficiency, and Performance Ratio as inputs. The effects of using different fuzzy inference types, either Sugeno- or Mamdani-type, and of changing the number of input membership functions to the error between the calibration data and the model-generated outputs were also illustrated. The solution spaces of the three methods were consequently examined with a sensitivity analysis. ANFIS exhibited the lowest error while DAFIS gave slightly lower errors compared to FIS. Increasing the number of input membership functions helped with error reduction in some cases but, at times, resulted in the opposite. Sugeno-type models gave errors that are slightly lower than those of the Mamdani-type. While ANFIS is superior in terms of error minimization, it could generate solutions that are questionable, i.e. the negative GWP values of the Solar PV system when the inputs were all at the upper end of their range. This shows that the applicability of the ANFIS models highly depends on the range of cases at which it was calibrated. FIS and DAFIS generated more intuitive trends in the sensitivity runs. DAFIS demonstrated an optimal design point wherein increasing the input values does not improve the GWP and LCOE anymore. In the absence of data that could be used for calibration, conventional FIS presents a knowledge-based model that could be used for prediction. In the PV case study, conventional FIS generated errors that are just slightly higher than those of DAFIS. The inherent complexity of a Life Cycle study often hinders its widespread use in the industry and policy-making sectors. While the methodology does not guarantee a more accurate result compared to those generated by the Life Cycle Methodology, it does provide a relatively simpler way of generating knowledge- and data-based estimates that could be used during the initial design of a system.

Keywords: solar photovoltaic, fuzzy logic, inference system, artificial neural networks

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Authors: Eyosiyas Aga

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The development of information communication technology has transformed the paper-based mapping and land registration processes to a computerized and networked system. The computerization and networking of real property information system play a vital role in good governance and sustainable development of emerging countries through cost effective, easy and accessible service delivery for the customer. The efficient, transparent and sustainable real property system is becoming the basic infrastructure for the urban development thus improve the data management system and service delivery in the organizations. In Ethiopia, the real property administration is paper based as a result, it confronted problems of data management, illegal transactions, corruptions, and poor service delivery. In order to solve this problem and to facilitate real property market, the implementation of web-based real property updating system is crucial. A web-based real property updating is one of the automation (computerizations) methods to facilitate data sharing, reduce time and cost of the service delivery in real property administration system. In additions, it is useful for the integration of data onto different information systems and organizations. This system is designed by combining open source software which supported by open Geo-spatial consortium. The web-based system is mainly designed by using open source software with the help of open Geo-spatial Consortium. The Open Geo-spatial Consortium standards such as the Web Feature Service and Web Map Services are the most widely used standards to support and improves web-based real property updating. These features allow the integration of data from different sources, and it can be used to maintain consistency of data throughout transactions. The PostgreSQL and Geoserver are used to manage and connect a real property data to the flex viewer and user interface. The system is designed for both internal updating system (municipality); which is mainly updating of spatial and textual information, and the external system (customer) which focus on providing and interacting with the customer. This research assessed the potential of open source web applications and adopted this technology for real property updating system in Ethiopia through simple, cost effective and secured way. The system is designed by combining and customizing open source software to enhance the efficiency of the system in cost effective way. The existing workflow for real property updating is analyzed to identify the bottlenecks, and the new workflow is designed for the system. The requirement is identified through questionnaire and literature review, and the system is prototype for the study area. The research mainly aimed to integrate human resource with technology in designing of the system to reduce data inconsistency and security problems. In additions, the research reflects on the current situation of real property administration and contributions of effective data management system for efficient, transparent and sustainable urban development in Ethiopia.

Keywords: cadaster, real property, sustainable, transparency, web feature service, web map service

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Authors: Yesim Tumsek, Erkan Celebi

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In order to simulate the infinite soil medium for soil-foundation interaction problem, the essential geotechnical parameter on which the foundation stiffness depends, is the value of soil shear modulus. This parameter directly affects the site and structural response of the considered model under earthquake ground motions. Strain-dependent shear modulus under cycling loads makes difficult to estimate the accurate value in computation of foundation stiffness for the successful dynamic soil-structure interaction analysis. The aim of this study is to discuss in detail how to use the appropriate value of soil shear modulus in the computational analyses and to evaluate the effect of the variation in shear modulus with strain on the impedance functions used in the sub-structure method for idealizing the soil-foundation interaction problem. Herein, the impedance functions compose of springs and dashpots to represent the frequency-dependent stiffness and damping characteristics at the soil-foundation interface. Earthquake-induced vibration energy is dissipated into soil by both radiation and hysteretic damping. Therefore, flexible-base system damping, as well as the variability in shear strengths, should be considered in the calculation of impedance functions for achievement a more realistic dynamic soil-foundation interaction model. In this study, it has been written a Matlab code for addressing these purposes. The case-study example chosen for the analysis is considered as a 4-story reinforced concrete building structure located in Istanbul consisting of shear walls and moment resisting frames with a total height of 12m from the basement level. The foundation system composes of two different sized strip footings on clayey soil with different plasticity (Herein, PI=13 and 16). In the first stage of this study, the shear modulus reduction factor was not considered in the MATLAB algorithm. The static stiffness, dynamic stiffness modifiers and embedment correction factors of two rigid rectangular foundations measuring 2m wide by 17m long below the moment frames and 7m wide by 17m long below the shear walls are obtained for translation and rocking vibrational modes. Afterwards, the dynamic impedance functions of those have been calculated for reduced shear modulus through the developed Matlab code. The embedment effect of the foundation is also considered in these analyses. It can easy to see from the analysis results that the strain induced in soil will depend on the extent of the earthquake demand. It is clearly observed that when the strain range increases, the dynamic stiffness of the foundation medium decreases dramatically. The overall response of the structure can be affected considerably because of the degradation in soil stiffness even for a moderate earthquake. Therefore, it is very important to arrive at the corrected dynamic shear modulus for earthquake analysis including soil-structure interaction.

Keywords: clay soil, impedance functions, soil-foundation interaction, sub-structure approach, reduced shear modulus

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Authors: Christine P. Gibson, Ramona Alex, Michael Farney, Johana Vallejo-Elias, Mitra Esfandiarei

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Aortic aneurysm is the leading cause of death in Marfan syndrome (MFS), a connective tissue disorder caused by mutations in fibrillin-1 gene (FBN1). MFS aneurysm is characterized by weakening of the aortic wall due to elastin fibers fragmentation and disorganization. The above-average height and distinct physical features make young adults with MFS desirable candidates for competitive sports; but little is known about the exercise limit at which they will be at risk for aortic rupture. On the other hand, aerobic cardiovascular exercise has been shown to have protective effects on the heart and aorta. We have previously reported that mild aerobic exercise can delay the formation of aortic aneurysm in a mouse model of MFS. In this study, we aimed to investigate the effects of various levels of exercise intensity on the progression of aortic aneurysm in the mouse model. Starting at 4 weeks of age, we subjected control and MFS mice to different levels of exercise intensity (8m/min, 10m/min, 15m/min, and 20m/min, corresponding to 55%, 65%, 75%, and 85% of VO2 max, respectively) on a treadmill for 30 minutes per day, five days a week for the duration of the study. At 24 weeks of age, aortic tissue were isolated and subjected to structural and functional studies using histology and wire myography in order to evaluate the effects of different exercise routines on elastin fragmentation and organization and aortic wall elasticity/stiffness. Our data shows that exercise training at the intensity levels between 55%-75% significantly reduces elastin fragmentation and disorganization, with less recovery observed in 85% MFS group. The reversibility of elasticity was also significantly restored in MFS mice subjected to 55%-75% intensity; however, the recovery was less pronounced in MFS mice subjected to 85% intensity. Furthermore, our data shows that smooth muscle cells (SMCs) contractilion in response to vasoconstrictor agent phenylephrine (100nM) is significantly reduced in MFS aorta (54.84 ± 1.63 mN/mm2) as compared to control (95.85 ± 3.04 mN/mm2). At 55% of intensity, exercise did not rescue SMCs contraction (63.45 ± 1.70 mN/mm2), while at higher intensity levels, SMCs contraction in response to phenylephrine was restored to levels similar to control aorta [65% (81.88 ± 4.57 mN/mm2), 75% (86.22 ± 3.84 mN/mm2), and 85% (83.91 ± 5.42 mN/mm2)]. This study provides the first time evidence that high intensity exercise (e.g. 85%) may not provide the most beneficial effects on aortic function (vasoconstriction) and structure (elastin fragmentation, aortic wall elasticity) during the progression of aortic aneurysm in MFS mice. On the other hand, based on our observations, medium intensity exercise (e.g. 65%) seems to provide the utmost protective effects on aortic structure and function in MFS mice. These findings provide new insights into the potential capacity, in which MFS patients could participate in various aerobic exercise routines, especially in young adults affected by cardiovascular complications particularly aortic aneurysm. This work was funded by Midwestern University Research Fund.

Keywords: aerobic exercise, aortic aneurysm, aortic wall elasticity, elastin fragmentation, Marfan syndrome

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Authors: Mariam Mtunguja, Henry Laswai, Yasinta Muzanilla, Joseph Ndunguru

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Starchy tuberous roots of cassava provide food for people but also find application in various industries. Recently there has been the focus of concentrated research efforts to fully exploit its potential as a sustainable multipurpose crop. High starch yield is the important trait for commercial cassava production for the starch industries. Furthermore, cyanide present in cassava root poses a health challenge in the use of cassava for food. Farming communities where cassava is a staple food, prefer bitter (high cyanogenic) varieties as protection from predators and thieves. As a result, food insecure farmers prefer growing bitter cassava. This has led to cyanide intoxication to this farming communities. Cassava farmers can benefit from marketing cassava to starch producers thereby improving their income and food security. This will decrease dependency on cassava as staple food as a result of increased income and be able to afford other food sources. To achieve this, adequate information is required on the right cassava cultivars and appropriate harvesting period so as to maximize cassava production and profitability. This study aimed at identifying suitable cassava cultivars and optimum time of harvest to maximize starch production. Six commonly grown cultivars were identified and planted in a complete random block design and further analysis was done to assess variation in physicochemical characteristics, starch yield and cyanogenic potentials across three environments. The analysis showed that there is a difference in physicochemical characteristics between landraces (p ≤ 0.05), and can be targeted to different industrial applications. Among landraces, dry matter (30-39%), amylose (11-19%), starch (74-80%) and reducing sugars content (1-3%) varied when expressed on a dry weight basis (p ≤ 0.05); however, only one of the six genotypes differed in crystallinity and mean starch granule particle size, while glucan chain distribution and granule morphology were the same. In contrast, the starch functionality features measured: swelling power, solubility, syneresis, and digestibility differed (p ≤ 0.05). This was supported by Partial least square discriminant analysis (PLS-DA), which highlighted the divergence among the cassavas based on starch functionality, permitting suggestions for the targeted uses of these starches in diverse industries. The study also illustrated genotypic difference in starch yield and cyanogenic potential. Among landraces, Kiroba showed potential for maximum starch yield (12.8 t ha-1) followed by Msenene (12.3 t ha-1) and third was Kilusungu (10.2 t ha-1). The cyanide content of cassava landraces was between 15 and 800 ppm across all trial sites. GGE biplot analysis further confirmed that Kiroba was a superior cultivar in terms of starch yield. Kilusungu had the highest cyanide content and average starch yield, therefore it can also be suitable for use in starch production.

Keywords: cyanogen, cassava starch, food security, starch yield

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Authors: Nkechi V. Osuji

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The use of blockchain to address the issue of climate change is increasingly a discourse among countries, industries, and stakeholders. For a long time, the European Union (EU) has been combating the issue of climate action in industries through sustainability programs. One of such programs is the EU monitoring reporting and verification (MRV) program of the EU ETS. However, the system has some key challenges and areas for improvement, which makes it inefficient. The main objective of the research is to look at how blockchain can be used to improve the inefficiency of the EU ETS program for the Danish energy industry with a focus on its monitoring and reporting framework. Applying empirical data from 13 semi-structured expert interviews, three case studies, and literature reviews, three outcomes are presented in the study. The first is on the current conditions and challenges of monitoring and reporting CO₂ emission trading. The second is putting into consideration if blockchain is the right fit to solve these challenges and how. The third stage looks at the factors that might affect the implementation of such a system and provides recommendations to mitigate these challenges. The first stage of the findings reveals that the monitoring and reporting of CO₂ emissions is a mandatory requirement by law for all energy operators under the EU ETS program. However, most energy operators are non-compliant with the program in reality, which creates a gap and causes challenges in the monitoring and reporting of CO₂ emission trading. Other challenges the study found out are the lack of transparency, lack of standardization in CO₂ accounting, and the issue of double-counting in the current system. The second stage of the research was guided by three case studies and requirement engineering (RE) to explore these identified challenges and if blockchain is the right fit to address them. This stage of the research addressed the main research question: how can blockchain be used for monitoring and reporting CO₂ emission trading in the energy industry. Through analysis of the study data, the researcher developed a conceptual private permissioned Hyperledger blockchain and elucidated on how it can address the identified challenges. Particularly, the smart contract of blockchain was highlighted as a key feature. This is because of its ability to automate, be immutable, and digitally enforce negotiations without a middleman. These characteristics are unique in solving the issue of compliance, transparency, standardization, and double counting identified. The third stage of the research presents technological constraints and a high level of stakeholder collaboration as major factors that might affect the implementation of the proposed system. The proposed conceptual model requires high-level integration with other technologies such as the Internet of Things (IoT) and machine learning. Therefore, the study encourages future research in these areas. This is because blockchain is continually evolving its technology capabilities. As such, it remains a topic of interest in research and development for addressing climate change. Such a study is a good contribution to creating sustainable practices to solve the global climate issue.

Keywords: blockchain, carbon emission trading, European Union emission trading system, monitoring and reporting

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Authors: Julio Jesus Salazar, Manuel Andres Jesus De Lama

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There are very few models that serve to analyze the use of water in the socio-economic process. On the supply side, the joint use of groundwater has been considered in addition to the simple limits on the availability of surface water. In addition, we have worked on waterlogging and the effects on water quality (mainly salinity). In this paper, a 'complex' water economy is examined; one in which demands grow differentially not only within but also between sectors, and one in which there are limited opportunities to increase consumptive use. In particular, high-value growth, the growth of the production of irrigated crops of high value within the basins of the case study, together with the rapidly growing urban areas, provides a rich context to examine the general problem of water management at the basin level. At the same time, the long-term aridity of nature has made the eco-environment in the basins located on the coast of Peru very vulnerable, and the exploitation and immediate use of water resources have further deteriorated the situation. The presented methodology is the optimization with embedded simulation. The wide basin simulation of flow and water balances and crop growth are embedded with the optimization of water allocation, reservoir operation, and irrigation scheduling. The modeling framework is developed from a network of river basins that includes multiple nodes of origin (reservoirs, aquifers, water courses, etc.) and multiple demand sites along the river, including places of consumptive use for agricultural, municipal and industrial, and uses of running water on the coast of Peru. The economic benefits associated with water use are evaluated for different demand management instruments, including water rights, based on the production and benefit functions of water use in the urban agricultural and industrial sectors. This work represents a new effort to analyze the use of water at the regional level and to evaluate the modernization of the integrated management of water resources and socio-economic territorial development in Peru. It will also allow the establishment of policies to improve the process of implementation of the integrated management and development of water resources. The input-output analysis is essential to present a theory about the production process, which is based on a particular type of production function. Also, this work presents the Computable General Equilibrium (CGE) version of the economic model for water resource policy analysis, which was specifically designed for analyzing large-scale water management. As to the platform for CGE simulation, GEMPACK, a flexible system for solving CGE models, is used for formulating and solving CGE model through the percentage-change approach. GEMPACK automates the process of translating the model specification into a model solution program.

Keywords: water economy, simulation, modeling, integration

Procedia PDF Downloads 133

Authors: Xu Wang

Abstract:

This research builds linear regressions of U.S. macroeconomic condition and volatility measures in the investment grade and high yield Credit Default Swap index spreads using monthly data from March 2009 to July 2016, to study the relationship between different dimensions of macroeconomy and overall credit risk quality. The most significant contribution of this research is systematically examining individual and joint effects of macroeconomic condition and volatility on CDX spreads by including macroeconomic time series that captures different dimensions of the U.S. economy. The industrial production index growth, non-farm payroll growth, consumer price index growth, 3-month treasury rate and consumer sentiment are introduced to capture the condition of real economic activity, employment, inflation, monetary policy and risk aversion respectively. The conditional variance of the macroeconomic series is constructed using ARMA-GARCH model and is used to measure macroeconomic volatility. The linear regression model is conducted to capture relationships between monthly average CDX spreads and macroeconomic variables. The Newey–West estimator is used to control for autocorrelation and heteroskedasticity in error terms. Furthermore, the sensitivity factor analysis and standardized coefficients analysis are conducted to compare the sensitivity of CDX spreads to different macroeconomic variables and to compare relative effects of macroeconomic condition versus macroeconomic uncertainty respectively. This research shows that macroeconomic condition can have a negative effect on CDX spread while macroeconomic volatility has a positive effect on determining CDX spread. Macroeconomic condition and volatility variables can jointly explain more than 70% of the whole variation of the CDX spread. In addition, sensitivity factor analysis shows that the CDX spread is the most sensitive to Consumer Sentiment index. Finally, the standardized coefficients analysis shows that both macroeconomic condition and volatility variables are important in determining CDX spread but macroeconomic condition category of variables have more relative importance in determining CDX spread than macroeconomic volatility category of variables. This research shows that the CDX spread can reflect the individual and joint effects of macroeconomic condition and volatility, which suggests that individual investors or government should carefully regard CDX spread as a measure of overall credit risk because the CDX spread is influenced by macroeconomy. In addition, the significance of macroeconomic condition and volatility variables, such as Non-farm Payroll growth rate and Industrial Production Index growth volatility suggests that the government, should pay more attention to the overall credit quality in the market when macroecnomy is low or volatile.

Keywords: autoregressive moving average model, credit spread puzzle, credit default swap spread, generalized autoregressive conditional heteroskedasticity model, macroeconomic conditions, macroeconomic uncertainty

Procedia PDF Downloads 148

Authors: Yang Yang, Luciana Magalhães Rebelo Alencar, Martha Sahylí Ortega Pijeira, Beatriz da Silva Batista, Alefe Roger Silva França, Erick Rafael Dias Rates, Ruana Cardoso Lima, Sara Gemini-Piperni, Ralph Santos-Oliveira

Abstract:

Radium-²²³ dichloride ([²²³Rₐ]RₐCl₂) is an alpha particle-emitting radiopharmaceutical currently approved for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases, and no known visceral metastatic disease. [²²³Rₐ]RₐCl₂ is bone-seeking calcium mimetic that bonds into the newly formed bone stroma, especially osteoblastic or sclerotic metastases, killing the tumor cells by inducing DNA breaks in a potent and localized manner. Nonetheless, the successful therapy of osteosarcoma as primary bone tumors is still a challenge. Nanomicelles are colloidal nanosystems widely used in drug development to improve blood circulation time, bioavailability, and specificity of therapeutic agents, among other applications. In addition, the enhanced permeability and retention effect of the nanosystems, and the renal excretion of the nanomicelles reported in most cases so far, are very attractive to achieve selective and increased accumulation in tumor site as well as to increase the safety of [²²³Rₐ]RₐCl₂ in the clinical routine. In the present work, [²²³Rₐ]RₐCl₂ nanomicelles were produced, characterized, in vitro evaluated, and compared with pure [²²³Rₐ]RₐCl2 solution using SAOS2 osteosarcoma cells. The [²²³Rₐ]RₐCl₂ nanomicelles were prepared using the amphiphilic copolymer Pluronic F127. The dynamic light scattering analysis of freshly produced [²²³Rₐ]RₐCl₂ nanomicelles demonstrated a mean size of 129.4 nm with a polydispersity index (PDI) of 0.303. After one week stored in the refrigerator, the mean size of the [²²³Rₐ]RₐCl₂ nanomicelles increased to 169.4 with a PDI of 0.381. Atomic force microscopy analysis of [223Rₐ]RₐCl₂ nanomicelles exhibited spherical structures whose heights reach 1 µm, suggesting the filling of 127-Pluronic nanomicelles with [²²³Rₐ]RₐCl₂. The viability assay with [²²³Rₐ]RₐCl₂ nanomicelles displayed a dose-dependent response as it was observed using pure [²²³Rₐ]RₐCl2. However, at the same dose, [²²³Rₐ]RₐCl₂ nanomicelles were 20% higher efficient in killing SAOS2 cells when compared with pure [²²³Rₐ]RₐCl₂. These findings demonstrated the effectiveness of the nanosystem validating the application of nanotechnology in targeted alpha therapy with [²²³Ra]RₐCl₂. In addition, the [²²³Rₐ]RaCl₂nanomicelles may be decorated and incorporated with a great variety of agents and compounds (e.g., monoclonal antibodies, aptamers, peptides) to overcome the limited use of [²²³Ra]RₐCl₂.

Keywords: nanomicelles, osteosarcoma, radium dichloride, targeted alpha therapy

Procedia PDF Downloads 99

Authors: Renée M. Ripken, Johannes G. E. Gardeniers, Séverine Le Gac

Abstract:

Controlling the multiphase behavior of aqueous biomass mixtures is essential when working in the biomass conversion industry. Here, the vapor/liquid equilibria (VLE) of ethylene glycol, glycerol, and xylitol were studied for temperatures between 25 and 200 °C and pressures of 1 to 10 bar. These experiments were performed in a microfluidic platform, which exhibits excellent heat transfer properties so that equilibrium is reached fast. Firstly, the saturated vapor pressure as a function of the temperature and the substrate mole fraction of the substrate was calculated using AspenPlus with a Redlich-Kwong-Soave Boston-Mathias (RKS-BM) model. Secondly, we developed a high-pressure and high-temperature microfluidic set-up for experimental validation. Furthermore, we have studied the multiphase flow pattern that occurs after the saturation temperature was achieved. A glass-silicon microfluidic device containing a 0.4 or 0.2 m long meandering channel with a depth of 250 μm and a width of 250 or 500 μm was fabricated using standard microfabrication techniques. This device was placed in a dedicated chip-holder, which includes a ceramic heater on the silicon side. The temperature was controlled and monitored by three K-type thermocouples: two were located between the heater and the silicon substrate, one to set the temperature and one to measure it, and the third one was placed in a 300 μm wide and 450 μm deep groove on the glass side to determine the heat loss over the silicon. An adjustable back pressure regulator and a pressure meter were added to control and evaluate the pressure during the experiment. Aqueous biomass solutions (10 wt%) were pumped at a flow rate of 10 μL/min using a syringe pump, and the temperature was slowly increased until the theoretical saturation temperature for the pre-set pressure was reached. First and surprisingly, a significant difference was observed between our theoretical saturation temperature and the experimental results. The experimental values were 10’s of degrees higher than the calculated ones and, in some cases, saturation could not be achieved. This discrepancy can be explained in different ways. Firstly, the pressure in the microchannel is locally higher due to both the thermal expansion of the liquid and the Laplace pressure that has to be overcome before a gas bubble can be formed. Secondly, superheating effects are likely to be present. Next, once saturation was reached, the flow pattern of the gas/liquid multiphase system was recorded. In our device, the point of nucleation can be controlled by taking advantage of the pressure drop across the channel and the accurate control of the temperature. Specifically, a higher temperature resulted in nucleation further upstream in the channel. As the void fraction increases downstream, the flow regime changes along the channel from bubbly flow to Taylor flow and later to annular flow. All three flow regimes were observed simultaneously. The findings of this study are key for the development and optimization of a microreactor for hydrogen production from biomass.

Keywords: biomass conversion, high pressure and high temperature microfluidics, multiphase, phase diagrams, superheating

Procedia PDF Downloads 203

Authors: P. D. Pedrosa, J. M. A. Rebello, M. P. Cindra Fonseca

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Duplex stainless steels (DSS) exhibit a biphasic microstructure consisting of austenite and delta ferrite. Their high resistance to oxidation, and corrosion, even in H2S containing environments, allied to low cost when compared to conventional stainless steel, are some properties which make this material very attractive for several industrial applications. However, several of these industrial applications imposes cyclic loading to the equipments and in consequence fatigue damage needs to be a concern. A well-known way of improving the fatigue life of a component is by introducing compressive residual stress in its surface. Shot peening is an industrial working process which brings the material directly beneath component surface in a high mechanical compressive state, so inhibiting fatigue crack initiation. However, one must take into account the fact that the cyclic loading itself can reduce and even suppress these residual stresses, thus having undesirable consequences in the process of improving fatigue life by the introduction of compressive residual stresses. In the present work, shot peening was used to introduce residual stresses in several DSS samples. These were thereafter submitted to three different fatigue regimes: low, medium and high cycle fatigue. The evolution of the residual stress during loading were then examined on both surface and subsurface of the samples. It was used the DSS UNS S31803, with microstructure composed of 49% austenite and 51% ferrite. The treatment of shot peening was accomplished by the application of blasting in two Almen intensities of 0.25 and 0.39A. The residual stresses were measured by X-ray diffraction using the double exposure method and a portable equipment with CrK radiation and the (211) diffracting plane for the austenite phase and the (220) plane for the ferrite phase. It is known that residual stresses may arise when two regions of the same material experienced different degrees of plastic deformation. When these regions are separated in respect to each other on a scale that is large compared to the material's microstructure they are called macro stresses. In contrast, microstresses can largely vary over distances which are small comparable to the scale of the material's microstructure and must balance zero between the phases present. In the present work, special attention will be paid to the measurement of residual microstresses. Residual stress measurements were carried out in test pieces submitted to low, medium and high-cycle fatigue, in both longitudinal and transverse direction of the test pieces. It was found that after shot peening, the residual microstress is tensile in the austenite and compressive in the ferrite phases. It was hypothesized that the hardening behavior of the austenite after shot peening was probably due to its higher nitrogen content. Fatigue cycling can effectively change this stress state but this effect was found to be dependent of the shot peening intensity was well as the fatigue range.

Keywords: residual stresses, fatigue, duplex steel, shot peening

Procedia PDF Downloads 203

Authors: Eman Hegazy, Stefan Anderberg, Joakim Krook

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Urban water infrastructure is crucial for efficient and reliable water supply in growing cities. With the growth of cities, the need for maintenance and renewal of these systems increases but often goes unfulfilled due to a variety of reasons, such as limited funding, political priorities, or lack of public awareness. Neglecting the renewal needs of these systems can lead to frequent malfunctions and reduced quality and reliability of water supply, as well as increased costs and health and environmental hazards. It is important for cities to prioritize investment in water infrastructure and develop long-term plans to address renewal needs. Drawing general conclusions about the rate of renewal of urban water infrastructure systems at an international or national level can be challenging due to the influence of local management decisions. In many countries, the responsibility for water infrastructure management lies with the municipal authorities, who are responsible for making decisions about the allocation of resources for repair, maintenance, and renewal. These decisions can vary widely based on factors such as local finances, political priorities, and public perception of the importance of water infrastructure. As a result, it is difficult to make generalizations about the rate of renewal across different countries or regions. In Sweden, the situation is not different, and the information from Svenskt Vatten indicates that the rate of renewal varies across municipalities and can be insufficient, leading to a buildup of maintenance and renewal needs. This study aims to examine the adequacy of the rate of renewal of urban water infrastructure in Linköping case city in Sweden. Using a case study framework, the study will assess the current status of the urban water system and the need for renewal. The study will also consider the role of factors such as proper identification processes, limited funding, competing for political priorities, and local management decisions in contributing to insufficient renewal. The study investigates the following questions: (1) What is the current status of water and sewerage networks in terms of length, age distribution, and material composition, estimated total water leakage in the network per year, damages, leaks, and outages occur per year, both overall and by district? (2) What are the main causes of these damages, leaks, and interruptions, and how are they related to lack of maintenance and renewal? (3) What is the current status of renewal work for the water and sewerage networks, including the renewal rate and changes over time, recent renewal material composition, and the budget allocation for renewal and emergency repairs? (4) What factors influence the need for renewal and what conditions should be considered in the assessment? The findings of the study provide insights into the challenges facing urban water infrastructure and identify strategies for improving the rate of renewal to ensure a reliable and sustainable water supply.

Keywords: case study, infrastructure, management, renewal need, Sweden

Procedia PDF Downloads 81

Authors: Fatima Bouazza, Khadija Khedid, Lamiae Amallah, Aziz Mouhaddach, Basma Boukour, Jihane Ennadir, Rachida Hassikou

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In order to combine milk and its derived products conservation and flavoring, Moroccans often used aromatic and medicinal plants. These plant extracts are endowed with several nutritive and therapeutic properties. This study constitutes a first national assessment of physico-chemical quality of sheep’s milk from moroccan Sardi breed and the evaluation of the antibacterial effect of three medicinal plants extracts: Aloe barbadensis Miller, Thymus satureioides and Mentha pulegium on flora isolated from this sheep's milk. 100 milk samples were collected in four regions of Morocco. The bacteria isolated were identified by classical and molecular methods (16S rRNA sequencing) and tested, according to the disk method, for their sensitivity to several antibiotics. The physico-chemical analyzes of sheep’s milk concerned the pH, titratable acidity, density, dry extract, freezing point and contents of: fat, proteins, lactose and calcium. The essential oils (EOs) of T. satureioides and M .pulegium were extracted by hydrodistillation and analyzed by GC / MS, while the Aloe vera leaf pulp was analyzed by the methods of Harborne and HPLC. A total number of 125 bacteria have been identified. Significant resistance to chemical antibiotics has been noted in LABs. The average temperature value of milk is around 57.15 °C, the pH is 6.56, the titratable acidity is around 3.4 ° D, the density is 1.035g / cm³ , the total dry extract is around 169.5g / l, the ash (9.8g / l), the freezing point (- 0.556 °C) while the average fat content is 67.85g / l . The samples richest in fat belong to the region of Settat, cradle of the Sardi breed, with a maximum average value of 74.4g / l. The average protein is 56g / l, lactose (39.92g / l), and calcium (1.855g / l). Analysis of the major components of EOs revealed the dominance of borneol in the case of T. satureioides and of pulegone in M. pulegium. Aloe vera gel contains alkaloids, flavonoids, catechic tannins, saponins and 1.60 µg / ml of aloin. The plant extracts have a bactericidal effect on E. coli, Klebsiellaoxytoca and Staphylococci and bacteriostatic effect on LABs of technological interest (Lactobacillus). As a result of this study, it is believed that the consumption of sardi sheep’s milk would be of nutritional benefit. Its richness in fat and proteins predisposes it for biotechnological development in the manufacture of cheese and yogurt. Also, the use of aromatic and medicinal plants, as natural additives would be of great benefit to flavor and maintain its quality.

Keywords: sheep’s milk, lactic flora, antimicrobial power, aloe barbadensis miller, thymus satureioides, mentha pulegium

Procedia PDF Downloads 105

Authors: Xiaoling Ren, Guidong Yang

Abstract:

Ammonia, as one of the largest-volume industrial chemicals, is mostly produced by century-old Haber-Bosch process with extreme conditionsand high-cost. Under the circumstance, researchersarededicated in finding new ways to replace the Haber-Bosch process. Photocatalytic nitrogen fixation is a promising sustainable, clear and green strategy for ammonia synthesis, butit is still a big challenge due to the high activation energy for nitrogen. It is essential to develop an efficient photocatalyst for making this approach industrial application. Constructing chemisorption active sites through defect engineering can be defined as an effective and reliable means to improve nitrogen activation by forming the extraordinary coordination environment and electronic structure. Besides, the construction of three-dimensionally orderdmacroporous (3DOM) structured photocatalyst is considered to be one of effectivestrategiesto improve the activity due to it canincrease the diffusion rate of reactants in the interior, which isbeneficial to the mass transfer process of nitrogen molecules in photocatalytic nitrogen reduction. Herein, Fe doped 3DOM WO₃(Fe-3DOM WO₃) without noble metal cocatalysts is synthesized by a polystyrene-template strategy, which is firstly used for photocatalytic nitrogen fixation. To elucidate the chemical nature of the dopant, the X-ray diffraction (XRD) analysiswas conducted. The pure 3DOM WO₃ has a monoclinic type crystal structure. And no additional peak is observed in Fe doped 3DOM WO₃, indicating that the incorporation of Fe atoms did not result in a secondary phase formation. In order to confirm the morphologies of Fe-3DOM WO₃and 3DOM WO₃, scanning electron microscopy (SEM) was employed. The synthesized Fe-3DOM WO₃and 3DOM WO₃ both exhibit a highly ordered three dimensional inverse opal structure with interconnected pores. From high-resolution TEM image of Fe-3DOM WO₃, the ordered lattice fringes with a spacing of 3.84 Å can be assigned to the (001) plane of WO₃, which is consistent with the XRD results. Finally, the photocatalytic nitrogen reduction performance of 3DOM WO₃ and Fe doped 3DOM WO₃with various Fe contents were examined. As a result, both Fe-3DOM WO₃ samples achieve higher ammonia production rate than that of pure 3DOM WO₃, indicating that the doped Fe plays a critical role in the photocatalytic nitrogen fixation performance. To verify the reaction process upon N2 reduction on the Fe-3DOM WO₃, in-situ diffuse reflectance infrared Fourier-transform spectroscopy was employed to monitor the intermediates. The in-situ DRIFTS spectra of Fe-3DOM WO₃ exhibit the increased signals with the irradiation time from 0–60min in the N2 atmosphere. The above results prove that nitrogen is gradually hydrogenated to produce ammonia over Fe-3DOM WO₃. Thiswork would enrich our knowledge in designing efficient photocatalystsfor photocatalytic nitrogen reduction.

Keywords: ammonia, photocatalytic, nitrogen fixation, Fe doped 3DOM WO₃

Procedia PDF Downloads 148

Authors: Secil Kaya Gulen

Abstract:

Face to face and virtual classrooms that came up with different conditions and environments, but similar purposes have different characteristics. Although virtual classrooms have some similar facilities with face-to-face classes such as program, students, and administrators, they have no walls and corridors. Therefore, students can attend the courses from a distance and can control their own learning spaces. Virtual classrooms defined as simultaneous online environments where students in different places come together at the same time with the guidance of a teacher. Distance education and virtual classes require different intellectual and managerial skills and models. Therefore, for effective use of virtual classrooms, the virtual property should be taken into consideration. One of the most important factors that affect the spread and effective use of the virtual classrooms is the perceptions and opinions of students -as one the main participants-. Student opinions and recommendations are important in terms of providing information about the fulfillment of expectation. This will help to improve the applications and contribute to the more efficient implementations. In this context, ideas and perceptions of the students related to the virtual classrooms, in general, were determined in this study. Advantages and disadvantages of virtual classrooms expected contributions to the educational system and expected characteristics of virtual classrooms have examined in this study. Students of an online distance education graduate program in which all the courses offered by virtual classrooms have asked for their opinions. Online Distance Education Graduate Program has totally 19 students. The questionnaire that consists of open-ended and multiple choice questions sent to these 19 students and finally 12 of them answered the questionnaire. Analysis of the data presented as frequencies and percentages for each item. SPSS for multiple-choice questions and Nvivo for open-ended questions were used for analyses. According to the results obtained by the analysis, participants stated that they did not get any training on virtual classes before the courses; but they emphasize that newly enrolled students should be educated about the virtual classrooms. In addition, all participants mentioned that virtual classroom contribute their personal development and they want to improve their skills by gaining more experience. The participants, who mainly emphasize the advantages of virtual classrooms, express that the dissemination of virtual classrooms will contribute to the Turkish Education System. Within the advantages of virtual classrooms, ‘recordable and repeatable lessons’ and ‘eliminating the access and transportation costs’ are most common advantages according to the participants. On the other hand, they mentioned ‘technological features and keyboard usage skills affect the attendance’ is the most common disadvantage. Participants' most obvious problem during virtual lectures is ‘lack of technical support’. Finally ‘easy to use’, ‘support possibilities’, ‘communication level’ and ‘flexibility’ come to the forefront in the scope of expected features of virtual classrooms. Last of all, students' opinions about the virtual classrooms seems to be generally positive. Designing and managing virtual classrooms according to the prioritized features will increase the students’ satisfaction and will contribute to improve applications that are more effective.

Keywords: distance education, virtual classrooms, higher education, e-learning

Procedia PDF Downloads 252

Authors: Leto Leandra, Guaitini Caterina, Agosti Anna, Del Vecchio Lorenzo, Guarrasi Valeria, Cirlini Martina, Chiancone Benedetta

Abstract:

To the best of our knowledge, this study represents the first attempt to investigate the in vitro germination response of Rhus coriaria L., and its sprout chemical characterization. Rhus coriaria L., a species belonging to the Anacardiaceae family, is commonly called "sumac" and is cultivated, in different countries of the Mediterranean and the Middle East regions, to produce a spice with a sour taste, obtained from its dried and ground fruits. Moreover, since ancient times, many beneficial properties have been attributed to this plant that has been used, in the traditional medicine of several Asian countries, against various diseases, including liver and intestinal pathologies, ulcers and various inflammatory states. In the recent past, sumac was cultivated in the Southern regions of Italy to treat leather, but its cultivation was abandoned, and currently, sumac plants grow spontaneously in marginal areas. Recently, in Italy, the interest in this species has been growing again, thanks to its numerous properties; thus, it becomes imperative to deepen the knowledge of this plant. In this study, in order to set up an efficient in vitro seed germination protocol, sumac seeds collected from spontaneous plants grown in Sicily, an island in the South of Italy, were, firstly, subjected to different treatments, scarification (mechanical, physical and chemical), cold stratification and imbibition, to break their physical and physiological dormancy, then, treated seeds were in vitro cultured on media with different gibberellic acid (GA3) concentrations. Results showed that, without any treatment, only 5% of in vitro sown seeds germinated, while the germination percentage increased up to 19% after the mechanical scarification. A further significative improvement of germination percentages was recorded after the physical scarification, with (40.5%) or without (36.5%) 8 weeks of cold stratification, especially when seeds were sown on gibberellin enriched cultured media. Vitro-derived sumac sprouts, at different developmental stages, were chemically characterized, in terms of polyphenol and tannin content, as well as for their antioxidant activity, to evaluate this matrix as a potential novel food or as a source of bioactive compounds. Results evidenced how more developed sumac sprouts and, above all, their leaves are a wealthy source of polyphenols (78.4 GAE/g SS) and tannins (21.9 mg GAE/g SS), with marked antioxidant activity. The outcomes of this study will be of support the nursery sector and sumac growers in obtaining a higher number of plants in a shorter time; moreover, the sprout chemical characterization will contribute to the process of considering this matrix as a new source of bioactive compounds and tannins to be used in food and non-food sectors.

Keywords: bioactive compounds, germination pre-treatments, rhus coriaria l., tissue culture

Procedia PDF Downloads 75

Authors: Leto Leandra, Guaitini Caterina, Agosti Anna, Del Vecchio Lorenzo, Guarrasi Valeria, Cirlini Martina, Chiancone Benedetta

Abstract:

To the best of our knowledge, this study represents the first attempt to investigate the in vitro germination response of Rhus coriaria L. and its sprout chemical characterization. Rhus coriaria L., a species belonging to the Anacardiaceae family, is commonly called "sumac” and is cultivated, in different countries of the Mediterranean and the Middle East regions, to produce a spice with a sour taste, obtained from its dried and ground fruits. Moreover, since ancient times, many beneficial properties have been attributed to this plant that has been used, in the traditional medicine of several Asian countries, against various diseases, including liver and intestinal pathologies, ulcers, and various inflammatory states. In the recent past, sumac was cultivated in the Southern regions of Italy to treat leather, but its cultivation was abandoned, and currently, sumac plants grow spontaneously in marginal areas. Recently, in Italy, the interest in this species has been growing again, thanks to its numerous properties; thus, it becomes imperative to deepen the knowledge of this plant. In this study, in order to set up an efficient in vitro seed germination protocol, sumac seeds collected from spontaneous plants grown in Sicily, an island in the South of Italy, were, firstly, subjected to different treatments, scarification (mechanical, physical and chemical), cold stratification and imbibition, to break their physical and physiological dormancy, then, treated seeds were in vitro cultured on media with different gibberellic acid (GA3) concentrations. Results showed that, without any treatment, only 5% of in vitro sown seeds germinated, while the germination percentage increased up to 19% after the mechanical scarification. A further significative improvement of germination percentages was recorded after the physical scarification, with (40.5%) or without (36.5%) 8 weeks of cold stratification, especially when seeds were sown on gibberellin enriched cultured media. Vitro-derived sumac sprouts, at different developmental stages, were chemically characterized, in terms of polyphenol and tannin content, as well as for their antioxidant activity, to evaluate this matrix as a potential novel food or as a source of bioactive compounds. Results evidenced how more developed sumac sprouts and, above all, their leaves are a wealthy source of polyphenols (78.4 GAE/g SS) and tannins (21.9 mg GAE/g SS), with marked antioxidant activity. The outcomes of this study will be of support the nursery sector and sumac growers in obtaining a higher number of plants in a shorter time; moreover, the sprout chemical characterization will contribute to the process of considering this matrix as a new source of bioactive compounds and tannins to be used in food and non-food sectors.

Keywords: bioactive compounds, germination pre-treatments, rhus coriaria l., tissue culture

Procedia PDF Downloads 77

Authors: Catariny C. Aleman, Flavio B. Campos, Matheus A. Caliman, Everardo C. Mantovani

Abstract:

The seedling production stage is a critical point in the vegetable production system. Obtaining high-quality seedlings is a prerequisite for subsequent cropping to occur well and productivity optimization is required. The water management is an important step in agriculture production. The adequate water requirement in horticulture seedlings can provide higher quality and increase field production. The practice of irrigation is indispensable and requires a duly adjusted quality irrigation system, together with a specific water management plan to meet the water demand of the crop. Irrigation management in seedling management requires a great deal of specific information, especially when it involves the use of inputs such as hydrorentering polymers and automation technologies of the data acquisition and irrigation system. The experiment was conducted in a greenhouse at the Federal University of Viçosa, Viçosa - MG. Tomato seedlings (Lycopersicon esculentum Mill) were produced in plastic trays of 128 cells, suspended at 1.25 m from the ground. The seedlings were irrigated by 4 micro sprinklers of fixed jet 360º per tray, duly isolated by sideboards, following the methodology developed for this work. During Phase 1, in January / February 2017 (duration of 24 days), the cultivation coefficient (Kc) of seedlings cultured in the presence and absence of hydrogel was evaluated by weighing lysimeter. In Phase 2, September 2017 (duration of 25 days), the seedlings were submitted to 4 irrigation managements (Kc, timer, 0.50 ETo, and 1.00 ETo), in the presence and absence of hydrogel and then evaluated in relation to quality parameters. The microclimate inside the greenhouse was monitored with the use of air temperature, relative humidity and global radiation sensors connected to a microcontroller that performed hourly calculations of reference evapotranspiration by Penman-Monteith standard method FAO56 modified for the balance of long waves according to Walker, Aldrich, Short (1983), and conducted water balance and irrigation decision making for each experimental treatment. Kc of seedlings cultured on a substrate with hydrogel (1.55) was higher than Kc on a pure substrate (1.39). The use of the hydrogel was a differential for the production of earlier tomato seedlings, with higher final height, the larger diameter of the colon, greater accumulation of a dry mass of shoot, a larger area of crown projection and greater the rate of relative growth. The handling 1.00 ETo promoted higher relative growth rate.

Keywords: automatic system; efficiency of water use; precision irrigation, micro sprinkler.

Procedia PDF Downloads 97

Authors: Taro Komori, Toshiki Gushi, Akihito Anzai, Taku Hirose, Kaoru Toko, Shinji Isogami, Takashi Suemasu

Abstract:

Ferrimagnetic antiperovskite Mn₄₋ₓNiₓN thin film exhibits both small saturation magnetization and rather large perpendicular magnetic anisotropy (PMA) when x is small. Both of them are suitable features for application to current induced domain wall motion devices using spin transfer torque (STT). In this work, we successfully grew antiperovskite 30-nm-thick Mn₄₋ₓNiₓN epitaxial thin films on MgO(001) and STO(001) substrates by MBE in order to investigate their crystalline qualities and magnetic and magneto-transport properties. Crystalline qualities were investigated by X-ray diffraction (XRD). The magnetic properties were measured by vibrating sample magnetometer (VSM) at room temperature. Anomalous Hall effect was measured by physical properties measurement system. Both measurements were performed at room temperature. Temperature dependence of magnetization was measured by VSM-Superconducting quantum interference device. XRD patterns indicate epitaxial growth of Mn₄₋ₓNiₓN thin films on both substrates, ones on STO(001) especially have higher c-axis orientation thanks to greater lattice matching. According to VSM measurement, PMA was observed in Mn₄₋ₓNiₓN on MgO(001) when x ≤ 0.25 and on STO(001) when x ≤ 0.5, and MS decreased drastically with x. For example, MS of Mn₃.₉Ni₀.₁N on STO(001) was 47.4 emu/cm³. From the anomalous Hall resistivity (ρAH) of Mn₄₋ₓNiₓN thin films on STO(001) with the magnetic field perpendicular to the plane, we found out Mr/MS was about 1 when x ≤ 0.25, which suggests large magnetic domains in samples and suitable features for DW motion device application. In contrast, such square curves were not observed for Mn₄₋ₓNiₓN on MgO(001), which we attribute to difference in lattice matching. Furthermore, it’s notable that although the sign of ρAH was negative when x = 0 and 0.1, it reversed positive when x = 0.25 and 0.5. The similar reversal occurred for temperature dependence of magnetization. The magnetization of Mn₄₋ₓNiₓN on STO(001) increases with decreasing temperature when x = 0 and 0.1, while it decreases when x = 0.25. We considered that these reversals were caused by magnetic compensation which occurred in Mn₄₋ₓNiₓN between x = 0.1 and 0.25. We expect Mn atoms of Mn₄₋ₓNiₓN crystal have larger magnetic moments than Ni atoms do. The temperature dependence stated above can be explained if we assume that Ni atoms preferentially occupy the corner sites, and their magnetic moments have different temperature dependence from Mn atoms at the face-centered sites. At the compensation point, Mn₄₋ₓNiₓN is expected to show very efficient STT and ultrafast DW motion with small current density. What’s more, if angular momentum compensation is found, the efficiency will be best optimized. In order to prove the magnetic compensation, X-ray magnetic circular dichroism will be performed. Energy dispersive X-ray spectrometry is a candidate method to analyze the accurate composition ratio of samples.

Keywords: compensation, ferrimagnetism, Mn₄N, PMA

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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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Authors: Min Koo Choi

Abstract:

The paper will examine Im Sun-dŭk’s two short stories, 'Iryoil' (Sunday, 1937) and 'Nazuoya' (A Godmother, 1942), which illuminate the subjects of Korean intellectuals going through the later period of a harsh and oppressive Japanese colonial rule. When Japan went to war against China in 1937, Korea, a colony of Japan since 1910, became an outpost for Japanese expansionism into China, and the Korean people were mobilized into the war effort. Nationalist movements and radical ideas that posed a threat and opposition to Japanese colonial rule in Korea and its colonial expansionism were ruthlessly suppressed, and Koreans were forcibly assimilated into becoming Japanese citizens without political rights. Racial discrimination between Koreans and Japanese was prevalent. Im Sun-dŭk, who participated in the Socialist movement in the 1930s, had his debut as a literary writer and a critic in the late 1930s, when Korean literary society was reincorporated in order to collaborate with the Japanese war effort through writing and public speech. Sun-duk's writing illuminates the unique internal landscape of a female subject who strives to live on while preserving her commitment and dignity under the circumstances that force Korean intellectuals either to collaborate with or acquiesce to Japanese colonial rule. 'Iryoil' (Sunday, 1937) foregrounds an educated intellectual, Hyeyŏng, who supplies her fiancé in prison for political involvement in resistance against Japan. On Sundays, she turns down her friends’ suggestion for enjoying holidays outside, due to her indebtedness to her fiancé. Her fiancé's imprisonment indicates the social conscience that still remains, and she seeks to share the commitment and suffering with her fiancé. The short story 'Nazuoya' (A Godmother, 1942), written in Japanese due to the suppression of Korean language publications at the time, also problematizes Japanese policy that forces Koreans to change their names into Japanese. Through the narrator I, who struggles to find a meaningful name for her cousin brother’s baby, she highlights how meaningful one’s name is for one’s life and identity. What makes her two stories unique is that her writing draws other people’s confessions into its own narrative through fragmentary forms, such as part of letter or reflection. The voices of others are intersected with the main character in 'Iryoil' (Sunday, 1937) and a narrator in 'Nazuoya' (A Godmother, 1942). In many ways, the narrator and main character provide the confessional voices who display the characters' gloomy interiorities. Even though these confessional voices do not share the commitment and values, both the main character and I in the stories reveal a more open set of viewpoints to them. In this way, they seek to form bonds and encouragement and acquire a more resilient sensibility that embraces those who strive to survive and endure in the gloomy days of the later period of Japanese colonial rule.

Keywords: Im Sun-dŭk, Japanese colonial rule, Korean literature, socialist movement

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Authors: Meryam Labyad, Karima Fakiri, Widad Lahmini, Ghizlane Draiss, Mohamed Bouskraoui, Nadia Ouzennou

Abstract:

Background: Asthma is the most common chronic disease in children, affecting nearly 235 million people worldwide (OMS). In Morocco, asthma is much more common in children than in adults; the prevalence rate in children between 13 and 14 years of age is 20%.1 This pathology is marked by high morbidity, a significant impact on the quality of life and development of children 2 This requires a rigorous management strategy in order to achieve clinical control and reduce any risk to the patient 3 A search for aggravating factors is mandatory if a child has difficulty maintaining good asthma control. The objective of the present study is to describe asthma control during this confinement period in children aged 4 to 11 years followed by a pneumo-paediatric consultation. For children whose asthma is not controlled, a search for associations with promoting factors and adherence to treatment is also among the objectives of the study. Knowing the level of asthma control and influencing factors is a therapeutic priority in order to reduce hospitalizations and emergency care use. Objective: To assess asthma control and determine the factors influencing asthma levels in children with asthma during confinement following the COVID 19 pandemic. Method: Prospective cross-sectional study by questionnaire and structured interview among 66 asthmatic children followed in pediatric pneumology consultation at the CHU MED VI of Marrakech from 13/06/2020 to 13/07/2020, asthma control was assessed by the Childhood Asthma Control Test (C-ACT). Results: 66 children and their parents were included (mean age is 7.5 years), asthma was associated with allergic rhinitis (13.5% of cases), conjunctivitis (9% of cases), eczema (12% of cases), occurrence of infection (10.5% of cases). The period of confinement was marked by a decrease in the number of asthma attacks translated by a decrease in the number of emergency room visits (7.5%) of these asthmatic children, control was well controlled in 71% of the children, this control was significantly associated with good adherence to treatment (p<0.001), no infection (p<0.001) and no conjunctivitis (p=002) or rhinitis (p<0.001). This improvement in asthma control during confinement can be explained by the measures taken in the Kingdom to prevent the spread of COVID 19 (school closures, reduction in industrial activity, fewer means of transport, etc.), leading to a decrease in children's exposure to triggers, which justifies the decrease in the number of children having had an infection, allergic rhinitis or conjunctivitis during this period. In addition, the close monitoring of parents resulted in better therapeutic adherence (42.4% were fully observant). Confinement was positively perceived by 68% of the parents; this perception is significantly associated with the level of asthma control (p<0.001). Conclusion: Maintaining good control can be achieved through improved therapeutic adherence and avoidance of triggers, both of which were achieved during the containment period following the VIDOC pandemic 19.

Keywords: Asthma, control , COVID-19 , children

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Authors: Geumchan Hwang

Abstract:

Professional sport leagues in Europe and North America are shut down due to novel coronavirus disease (COVID-19) outbreak. Football leagues in Europe (e.g., La Liga, English Premier League, Bundesliga, Serie A, and Ligue 1) and big four professional sport leagues in North America (e.g., National Football League, Major League Baseball, National Basketball Association, and National Hockey League) are indefinitely suspended or delayed. COVID-19 outbreak has a growing negative impact on economics of sport leagues. For example, loss of revenue in Europe’s top five leagues due to the COVID-19 pandemic was estimated at € 4 billion and loss of revenue in the NBA was estimated at $650 million as of March 2020. In the unprecedented difficult situation, sport teams and leagues try to communicate with sport fans through diverse media platforms. In sport, however, very few studies have been done regarding how sport organizations effectively communicate with sport fans during pandemics, such as COVID-19 outbreak. Understanding sport organizations’ crisis communication is important to develop effective crisis management strategies for sport organizations. Therefore, the purpose of the study is to examine how sport organizations communicate with sport fans via online platforms in COVID-19 outbreak and how sport fans evaluate their communication strategies. 9 official sport league sites (i.e., five major football leagues in Europe and four major sport leagues in North America) and COVID-19 news articles published between January and June in 2020 will be analyzed in terms of coronavirus information, teams and players’ live update, fan interaction, fan support, and community engagement. In addition, comments posted on social media sites (i.e., Facebook and Twitter) of major sport leagues will be also analyzed to examine how sport fans perceive online messages provided by sport leagues as an effective communication strategy. To measure the effectiveness of crisis communication performance, five components (i.e., prompt, compassionate, honest, informative, and interactive) of crisis communication will be collected from leagues’ official websites information and social media posts. Upon completing data collection, content analysis method will be used to evaluate effectiveness of crisis communication among 9 professional sport leagues. The results of the study will provide athletic directors, administrators, and public relations managers in sport organizations with practical information regarding how athlete celebrities and sport organizations should interact with their fans in pandemic situations. In particular, this study will contribute to developing specific crisis management plan for sport organizations. For instance, football teams and leagues in Europe will be able to create standard manuals to minimize damages caused by disease outbreak, such as COVID-19 outbreak.

Keywords: COVID-19, communication, sport leagues, fans

Procedia PDF Downloads 123