Search results for: green construction material

Authors: Helena Maragou

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Introducing Toni Morrison’s fiction to a classroom overseas entails a significant pedagogical investment, from monitoring students’ uncertain journey through Morrison’s shifty semantics to filling in the gaps of cultural knowledge and understanding for the students to be able to relate text to context. A rewarding process, as Morrison’s works present a tremendous opportunity for transnational dialogue, an opportunity that hinges upon Toni Morrison’s bringing to the fore the untold and unspeakable lives of racial ‘Others’, but also, crucially, upon her broader critique of Western ideological hegemony. This critique is a fundamental aspect of Toni Morrison’s politics and one that appeals to young readers of Toni Morrison in Greece at a time when the questioning of institutions and ideological traditions is precipitated by regional and global change. It is more or less self-evident that to help a class of international students get aboard a Morrison novel, an instructor should begin by providing them with cultural context. These days, students’ exposure to Hollywood representations of the African American past and present, as well as the use of documentaries, photography, music videos, etc., as supplementary class material, provide a starting point, a workable historical and cultural framework for textual comprehension. The true challenge, however, lies ahead: it is one thing for students to intellectually grasp the historical hardships and traumas of Morrison’s characters and to even engage in aesthetic appreciation of Morrison’s writing; quite another to relate to her works as articulations of experiences akin to their own. The great challenge, then, is in facilitating students’ discovery of the universal Morrison, the author who speaks across cultures while voicing the untold tales of her own people; this process of discovery entails, on a pedagogical level, that students be guided through the works’ historical context, to plunge into the intricacies of Morrison’s discourse, itself an elaborate linguistic booby trap, so as to be finally brought to reconsider their own historical experiences using the lens of Morrison’s fiction. The paper will be based on experience of teaching a Toni Morrison seminar to a class of Greek students at the American College of Greece and will draw from students’ exposure and responses to Toni Morrison’s “Nobel Prize Lecture,” as well as her novels Song of Solomon and Home.

Keywords: toni morrison, international classroom, pedagogy, African American literature

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Authors: Saidur R. Chowdhury, Mamme K. Addai, Ernest K. Yanful

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The research was performed to assess the potential of nickel smelter slag, an industrial waste, as an adsorbent in the removal of metals from aqueous solution. An investigation was carried out for Arsenic (As), Copper (Cu), lead (Pb) and Cadmium (Cd) adsorption from aqueous solution. Smelter slag was obtain from Ni ore at the Vale Inco Ni smelter in Sudbury, Ontario, Canada. The batch experimental studies were conducted to evaluate the removal efficiencies of smelter slag. The slag was characterized by surface analytical techniques. The slag contained different iron oxides and iron silicate bearing compounds. In this study, the effect of pH, contact time, particle size, competition by other ions, slag dose and distribution coefficient were evaluated to measure the optimum adsorption conditions of the slag as an adsorbent for As, Cu, Pb and Cd. The results showed 95-99% removal of As, Cu, Pb, and almost 50-60% removal of Cd, while batch experimental studies were conducted at 5-10 mg/L of initial concentration of metals, 10 g/L of slag doses, 10 hours of contact time and 170 rpm of shaking speed and 25oC condition. The maximum removal of Arsenic (As), Copper (Cu), lead (Pb) was achieved at pH 5 while the maximum removal of Cd was found after pH 7. The column experiment was also conducted to evaluate adsorption depth and service time for metal removal. This study also determined adsorption capacity, adsorption rate and mass transfer rate. The maximum adsorption capacity was found to be 3.84 mg/g for As, 4 mg/g for Pb, and 3.86 mg/g for Cu. The adsorption capacity of nickel slag for the four test metals were in decreasing order of Pb > Cu > As > Cd. Modelling of experimental data with Visual MINTEQ revealed that saturation indices of < 0 were recorded in all cases suggesting that the metals at this pH were under- saturated and thus in their aqueous forms. This confirms the absence of precipitation in the removal of these metals at the pHs. The experimental results also showed that Fe and Ni leaching from the slag during the adsorption process was found to be very minimal, ranging from 0.01 to 0.022 mg/L indicating the potential adsorbent in the treatment industry. The study also revealed that waste product (Ni smelter slag) can be used about five times more before disposal in a landfill or as a stabilization material. It also highlighted the recycled slags as a potential reactive adsorbent in the field of remediation engineering. It also explored the benefits of using renewable waste products for the water treatment industry.

Keywords: adsorption, industrial waste, recycling, slag, treatment

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Authors: Rajkumar Ghosh, Ananya Mukhopadhyay

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India has seen enormous urbanization in recent years, resulting in increased energy consumption and water demand in its metropolitan regions. Adoption of grid-connected solar rooftop systems and rainwater collection has gained significant popularity in urban areas to address these challenges while also boosting sustainability and environmental consciousness. Grid-connected solar rooftop systems offer a long-term solution to India's growing energy needs. Solar panels are erected on the rooftops of residential and commercial buildings to generate power by utilizing the abundant solar energy available across the country. Solar rooftop systems generate clean, renewable electricity, reducing reliance on fossil fuels and lowering greenhouse gas emissions. This is compatible with India's goal of reducing its carbon footprint. Urban residents and companies can save money on electricity by generating their own and possibly selling excess power back to the grid through net metering arrangements. India gives several financial incentives (subsidies 40% for system capacity 1 kW to 3 kW) to stimulate the building of solar rooftop systems, making them an economically viable option for city dwellers. India provides subsidies up to 70% to special states such as Uttarakhand, Sikkim, Himachal Pradesh, Jammu & Kashmir, and Lakshadweep. Incorporating solar rooftops into urban infrastructure contributes to sustainable urban expansion by alleviating pressure on traditional energy sources and improving air quality. Incorporating solar rooftops into urban infrastructure contributes to sustainable urban expansion by alleviating demand on existing energy sources and improving power supply reliability. Rainwater harvesting is another key component of India's sustainable urban development. It comprises collecting and storing rainwater for use in non-potable water applications such as irrigation, toilet flushing, and groundwater recharge. Rainwater gathering 2 helps to conserve water resources by lowering the demand for freshwater sources. This technology is crucial in water-stressed areas to ensure a sustainable water supply. Excessive rainwater runoff in metropolitan areas can lead to Urban flooding. Solar PV system with Rooftop Rainwater harvesting systems absorb and channel excess rainwater, which helps to reduce flooding and waterlogging in Smart cities. Rainwater harvesting systems are inexpensive and quick to set up, making them a tempting option for city dwellers and businesses looking to save money on water. Rainwater harvesting systems are now compulsory in several Indian states for specified types of buildings (bye law, Rooftop space ≥ 300 sq. m.), ensuring widespread adoption. Finally, grid-connected solar rooftop systems and rainwater collection are important to India's long-term urban development. They not only reduce the environmental impact of urbanization, but also empower individuals and businesses to control their energy and water requirements. The G20 summit will focus on green financing, fossil fuel phaseout, and renewable energy transition. The G20 Summit in New Delhi reaffirmed India's commitment to battle climate change by doubling renewable energy capacity. To address climate change and mitigate global warming, India intends to attain 280 GW of solar renewable energy by 2030 and Net Zero carbon emissions by 2070. With continued government support and increased awareness, these strategies will help India develop a more resilient and sustainable urban future.

Keywords: grid-connected solar PV system, rooftop rainwater harvesting, urban flood, groundwater, urban flooding, net zero carbon emission

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Authors: Ilma Robo, Saimir Heta, Rialda Xhizdari, Kers Kapaj

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Background: The ideal disinfectant for surfaces, instruments, air, skin, both in dentistry and in the fields of medicine, does not exist.This is for the sole reason that all the characteristics of the ideal disinfectant cannot be contained in one; these are the characteristics that if one of them is emphasized, it will conflict with the other. A disinfectant must be stable, not be affected by changes in the environmental conditions where it stands, which means that it should not be affected by an increase in temperature or an increase in the humidity of the environment. Both of these elements contradict the other element of the idea of an ideal disinfectant, as they disrupt the solubility ratios of the base substance of the disinfectant versus the diluent. Material and methods: The study aims to extract the constant of each disinfectant/antiseptic used during dental disinfection protocols, accompanied by the side effects of the surface of the skin or mucosa where it is applied in the role of antiseptic. In the end, attempts were made to draw conclusions about the best possible combination for disinfectants after a dental procedure, based on the data extracted from the basic literature required during the development of the pharmacology module, as a module in the formation of a dentist, against data published in the literature. Results: The sensitivity of the disinfectant to changes in the atmospheric conditions of the environment where it is kept is a known fact. The care against this element is always accompanied by the advice on the application of the specific disinfectant, in order to have the desired clinical result. The constants of disinfectants according to the classification based on the data collected and presented are for alcohols 70-120, glycols 0.2, aldehydes 30-200, phenols 15-60, acids 100, povidone iodine halogens 5-75, hypochlorous acid halogens 150, sodium hypochlorite halogens 30-35, oxidants 18-60, metals 0.2-10. The part of halogens should be singled out, where specific results were obtained according to the representatives of this class, since it is these representatives that find scope for clinical application in dentistry. Conclusions: The search for the "ideal", in the conditions where its defining criteria are also established, not only for disinfectants but also for any medication or pharmaceutical product, is an ongoing search, without any definitive results. In this mine of data in the published literature if there is something fixed, calculable, such as the specific constant for disinfectants, the search for the ideal is more concrete. During the disinfection protocols, different disinfectants are applied since the field of action is different, including water, air, aspiration devices, tools, disinfectants used in full accordance with the production indications.

Keywords: disinfectant, constant, ideal, side effects

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Authors: Vinay Kumar Vanjakula, Frank Adam, Nils Goseberg

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Wind power is one of the leading renewable energy generation methods. Due to abundant higher wind speeds far away from shore, the construction of offshore wind turbines began in the last decades. However, installation of offshore foundation-based (monopiles) wind turbines in deep waters are often associated with technical and financial challenges. To overcome such challenges, the concept of floating wind turbines is expanded as the basis from the oil and gas industry. The unfolding of Universal heavyweight gravity anchor (UGA) for floating based foundation for floating Tension Leg Platform (TLP) sub-structures is developed in this research work. It is funded by the German Federal Ministry of Education and Research) for a three-year (2019-2022) research program called “Offshore Wind Solutions Plus (OWSplus) - Floating Offshore Wind Solutions Mecklenburg-Vorpommern.” It’s a group consists of German institutions (Universities, laboratories, and consulting companies). The part of the project is focused on the numerical modeling of gravity anchor that involves to analyze and solve fluid flow problems. Compared to gravity-based torpedo anchors, these UGA will be towed and lowered via controlled machines (tug boats) at lower speeds. This kind of installation of UGA are new to the offshore wind industry, particularly for TLP, and very few research works have been carried out in recent years. Conventional methods for transporting the anchor requires a large transportation crane vessel which involves a greater cost. This conceptual UGA anchors consists of ballasting chambers which utilizes the concept of buoyancy forces; the inside chambers are filled with the required amount of water in a way that they can float on the water for towing. After reaching the installation site, those chambers are ballasted with water for lowering. After it’s lifetime, these UGA can be unballasted (for erection or replacement) results in self-rising to the sea surface; buoyancy chambers give an advantage for using an UGA without the need of heavy machinery. However, while lowering/rising the UGA towards/away from the seabed, it experiences difficult, harsh marine environments due to the interaction of waves and currents. This leads to drifting of the anchor from the desired installation position and damage to the lowering machines. To overcome such harsh environments problems, a numerical model is built to investigate the influences of different outer contours and other fluid governing shapes that can be installed on the UGA to overcome the turbulence and drifting. The presentation will highlight the importance of the Computational Fluid Dynamics (CFD) numerical model in OpenFOAM, which is open-source programming software.

Keywords: anchor lowering, towing, waves, currrents, computational fluid dynamics

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Authors: Ivelise M. Strozberg, Lucas O. Vale, Maria V. V. Morais

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Expansive soils are characterized by their significant volumetric variations, tending to suffer an increase of this volume when added water in their voids and a decrease of volume when this water is removed. The parameters of resistance (especially the angle of friction, cohesion and specific weight) of expansive or non-expansive soils of the same field present differences, as found in laboratory tests. What is expected is that, through this research, demonstrate that this variation directly affects the results of the calculation of factors of safety for slope stability. The expansibility due to specific clay minerals such as montmorillonites and vermiculites is the most common form of expansion of soils or rocks, causing expansion pressures. These pressures can become an aggravating problem in regions across the globe that, when not previously studied, may present high risks to the enterprise, such as cracks, fissures, movements in structures, breaking of retaining walls, drilling of wells, among others. The study provides results based on analyzes carried out in the Slide 2018 software belonging to the Rocsience group, where the software is a two-dimensional equilibrium slope stability program that calculates the factor of safety or probability of failure of certain surfaces composed of soils or rocks (or both, depending on the situation), - through the methods of: Bishop simplified, Fellenius and Janbu corrected. This research compares the factors of safety of a homogeneous earthfill dam geometry, analysed for operation and end-of-construction situations, having a height of approximately 35 meters, with a slope of 1.5: 1 in the slope downstream and 2: 1 on the upstream slope. As the water level is 32.73m high and the water table is drawn automatically by the Slide program using the finite element method for the operating situation, considering two hypotheses for the use of materials - the first with soils with characteristics of expansion and the second with soils without expansibility. For this purpose, soil samples were collected from the region of São Bento do Una - Pernambuco, Brazil and taken to the soil mechanics laboratory to characterize and determine the percentage of expansibility. There were found 2 types of soils in that area: 1 site of expansive soils (8%) and another with non- expansive ones. Based on the results found, the analysis of the values of factors of safety indicated, both upstream and downstream slopes, the highest values were obtained in the case where there is no presence of materials with expansibility resulting, for one of the situations, values of 1.353 (Fellenius), 1,295 (Janbu corrected) and 1,409 (Bishop simplified). There is a considerable drop in safety factors in cases where soils are potentially expansive, resulting in values for the same situation of 0.859 (Fellenius), 0.809 (Janbu corrected) and 0.842 (Bishop simplified), in the case of higher expansibility (8 %). This shows that the expansibility is a determinant factor in the fall of resistance of soil, determined by the factors of cohesion and angle of friction.

Keywords: dam. slope. software. swelling soil

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Authors: Aaron Herve Mbwe Mbissik, Lotfi Khiari, Otmane Raji, Abdellatif Elghali, Abdelkarim Lajili, Muhammad Ouabid, Martin Jemo, Jean-Louis Bodinier

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Potassium (K) is an essential macronutrient for plant growth, helping to regulate several physiological and metabolic processes. Evaporite-related potash salts, mainly sylvite minerals (K chloride or KCl), are the principal source of K for the fertilizer industry. However, due to the high potash-supply risk associated with its considerable price fluctuations and uneven geographic distribution for most agriculture-based developing countries, the development of alternative sources of fertilizer K is imperative to maintain adequate crop yield, reduce yield gaps, and food security. Alkaline Igneous rocks containing significant K-rich silicate minerals such as K feldspar are increasingly seen as the best alternative available. However, these rocks may require to be hydrothermally treatment to enhance the release of potassium. In this study, we evaluate the fertilizing capacity of raw and hydrothermally treated K-bearing silicate rocks from different areas in Morocco. The effectiveness of rock powders was tested in a greenhouse experiment using ryegrass (Lolium multiflorum) by comparing them to a control (no K added) and to a conventional fertilizer (muriate of potash: MOP or KCl). The trial was conducted in a randomized complete block design with three replications, and plants were grown on K-depleted soils for three growing cycles. To achieve our objective, in addition to the analysis of the muriate response curve and the different biomasses, we also examined three necessary coefficients, namely: the K uptake, then apparent K recovery (AKR), and the relative K efficiency (RKE). The results showed that based on the optimum economic rate of MOP (230 kg.K.ha⁻¹) and the optimum yield (44 000 kg.K.ha⁻¹), the efficiency of K silicate rocks was as high as that of MOP. Although the plants took up only half of the K supplied by the powdered rock, the hydrothermal material was found to be satisfactory, with a biomass value reaching the optimum economic limit until the second crop cycle. In comparison, the AKR of the MOP (98.6%) and its RKE in the 1st cycle were higher than our materials: 39% and 38%, respectively. Therefore, the raw and hydrothermal materials mixture could be an appropriate solution for long-term agronomic use based on the obtained results.

Keywords: K-uptake, AKR, RKE, K-bearing silicate rock, MOP

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Authors: Zdzisław Kobos, Robert Jędrys, Zbigniew Wochyński

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Motor activity and good health are sine qua non determinants of a proper practice of the profession, especially aviation. Therefore, candidates to the aviation are selected according their psychomotor ability by both specialist medical commissions. Moreover, they must past an examination of the physical fitness. During the studies in the air force academy, eye-hand coordination is formed in two stages. The future aircraft pilots besides all-purpose physical education must practice specialist training on SAGI. Training includes: looping, aerowheel, and gyroscope. Aim of the training on the above listed apparatuses is to form eye-hand coordination during the tasks in the air. Such coordination is necessary to perform various figures in the real flight. Therefore, during the education of the future pilots, determinants of the effective ways of this important parameter of the human body functioning are sought for. Several studies of the sport psychology indicate an important role of the temperament as a factor determining human behavior during the task performance and acquiring operating skills> Polish psychologist Jan Strelau refers to the basic, relatively constant personality features which manifest themselves in the formal characteristics of the human behavior. Temperament, being initially determined by the inborn physiological mechanisms, changes in the course of maturation and some environmental factors and concentrates on the energetic level and reaction characteristics in time. Objectives. This study aimed at seeking a relationship between temperamental features and eye-hand coordination formation during training on SAGI. Material and Methods: Group of 30 students of pilotage was examined in two situations. The first assessment of the eye-hand coordination level was carried out before the beginning of a 30-hour training on SAGI. The second assessment was carried out after training completion. Training lasted for 2 hours once a week. Temperament was evaluated with The Formal Characteristics of Behavior − Temperament Inventory (FCB-TI) developed by Bogdan Zawadzki and Jan Strelau. Eye-hand coordination was assessed with a computer version of the Warsaw System of Psychological Tests. Results: It was found that the training on SAGI increased the level of eye-hand coordination in the examined students. Conclusions: Higher level of the eye-hand coordination was obtained after completion of the training. Moreover, a relationship between eye-hand coordination level and selected temperamental features was statistically significant.

Keywords: temperament, eye-hand coordination, pilot, SAGI

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Authors: Ariadne C. Catto, Luis F. da Silva, Khalifa Aguir, Valmor Roberto Mastelaro

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Zinc oxide (ZnO) pure or doped are one of the most promising metal oxide semiconductors for gas sensing applications due to the well-known high surface-to-volume area and surface conductivity. It was shown that ZnO is an excellent gas-sensing material for different gases such as CO, O2, NO2 and ethanol. In this context, pure and doped ZnO exhibiting different morphologies and a high surface/volume ratio can be a good option regarding the limitations of the current commercial sensors. Different studies showed that the sensitivity of metal-doped ZnO (e.g. Co, Fe, Mn,) enhanced its gas sensing properties. Motivated by these considerations, the aim of this study consisted on the investigation of the role of Co ions on structural, morphological and the gas sensing properties of nanostructured ZnO samples. ZnO and Zn1-xCoxO (0 < x < 5 wt%) thin films were obtained via the polymeric precursor method. The sensitivity, selectivity, response time and long-term stability gas sensing properties were investigated when the sample was exposed to a different concentration range of ozone (O3) at different working temperatures. The gas sensing property was probed by electrical resistance measurements. The long and short-range order structure around Zn and Co atoms were investigated by X-ray diffraction and X-ray absorption spectroscopy. X-ray photoelectron spectroscopy measurement was performed in order to identify the elements present on the film surface as well as to determine the sample composition. Microstructural characteristics of the films were analyzed by a field-emission scanning electron microscope (FE-SEM). Zn1-xCoxO XRD patterns were indexed to the wurtzite ZnO structure and any second phase was observed even at a higher cobalt content. Co-K edge XANES spectra revealed the predominance of Co2+ ions. XPS characterization revealed that Co-doped ZnO samples possessed a higher percentage of oxygen vacancies than the ZnO samples, which also contributed to their excellent gas sensing performance. Gas sensor measurements pointed out that ZnO and Co-doped ZnO samples exhibit a good gas sensing performance concerning the reproducibility and a fast response time (around 10 s). Furthermore, the Co addition contributed to reduce the working temperature for ozone detection and improve the selective sensing properties.

Keywords: cobalt-doped ZnO, nanostructured, ozone gas sensor, polymeric precursor method

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Authors: Gayathri Devi V, Aravamudan Kannan, Amit Sircar

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In the inner fuel cycle system of a nuclear fusion reactor, the Hydrogen Isotopes Removal System (HIRS) plays a pivoted role. It enables the effective extraction of the hydrogen isotopes from the breeder purge gas which helps to maintain the tritium breeding ratio and sustain the fusion reaction. One of the components of HIRS, Cryogenic Molecular Sieve Bed (CMSB) columns with zeolites adsorbents are considered for the physisorption of hydrogen isotopes at 1 bar and 77 K. Even though zeolites have good thermal stability and reduced activation properties making them ideal for use in nuclear reactor applications, their modest capacity for hydrogen isotopes adsorption is a cause of concern. In order to enhance the adsorbent capacity in an informed manner, it is helpful to understand the adsorption phenomena at the quantum electronic structure level. Physicochemical modifications of the adsorbent material enhances the adsorption capacity through the incorporation of active sites. This may be accomplished through the incorporation of suitable metal ions in the zeolite framework. In this work, molecular hydrogen isotopes adsorption on the active sites of functionalized zeolites are investigated in detail using Density Functional Theory (DFT) study. This involves the utilization of hybrid Generalized Gradient Approximation (GGA) with dispersion correction to account for the exchange and correlation functional of DFT. The electronic energies, adsorption enthalpy, adsorption free energy, Highest Occupied Molecular Orbital (HOMO), Lowest Unoccupied Molecular Orbital (LUMO) energies are computed on the stable 8T zeolite clusters as well as the periodic structure functionalized with different active sites. The characteristics of the dihydrogen bond with the active metal sites and the isotopic effects are also studied in detail. Validation studies with DFT will also be presented for adsorption of hydrogen on metal ion functionalized zeolites. The ab-inito screening analysis gave insights regarding the mechanism of hydrogen interaction with the zeolites under study and also the effect of the metal ion on adsorption. This detailed study provides guidelines for selection of the appropriate metal ions that may be incorporated in the zeolites framework for effective adsorption of hydrogen isotopes in the HIRS.

Keywords: adsorption enthalpy, functionalized zeolites, hydrogen isotopes, nuclear fusion, physisorption

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Authors: Elaine Lima Da Fonseca, Eliomar Pereira Da Silva Filho

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The modeling of areas susceptible to soil loss by hydro erosive processes consists of a simplified instrument of reality with the purpose of predicting future behaviors from the observation and interaction of a set of geoenvironmental factors. The models of potential areas for soil loss will be obtained through binary logistic regression, artificial neural networks, and support vector machines. The choice of the municipality of Colorado do Oeste in the south of the western Amazon is due to soil degradation due to anthropogenic activities, such as agriculture, road construction, overgrazing, deforestation, and environmental and socioeconomic configurations. Initially, a soil erosion inventory map constructed through various field investigations will be designed, including the use of remotely piloted aircraft, orbital imagery, and the PLANAFLORO/RO database. 100 sampling units with the presence of erosion will be selected based on the assumptions indicated in the literature, and, to complement the dichotomous analysis, 100 units with no erosion will be randomly designated. The next step will be the selection of the predictive parameters that exert, jointly, directly, or indirectly, some influence on the mechanism of occurrence of soil erosion events. The chosen predictors are altitude, declivity, aspect or orientation of the slope, curvature of the slope, composite topographic index, flow power index, lineament density, normalized difference vegetation index, drainage density, lithology, soil type, erosivity, and ground surface temperature. After evaluating the relative contribution of each predictor variable, the erosion susceptibility model will be applied to the municipality of Colorado do Oeste - Rondônia through the SPSS Statistic 26 software. Evaluation of the model will occur through the determination of the values of the R² of Cox & Snell and the R² of Nagelkerke, Hosmer and Lemeshow Test, Log Likelihood Value, and Wald Test, in addition to analysis of the Confounding Matrix, ROC Curve and Accumulated Gain according to the model specification. The validation of the synthesis map resulting from both models of the potential risk of soil erosion will occur by means of Kappa indices, accuracy, and sensitivity, as well as by field verification of the classes of susceptibility to erosion using drone photogrammetry. Thus, it is expected to obtain the mapping of the following classes of susceptibility to erosion very low, low, moderate, very high, and high, which may constitute a screening tool to identify areas where more detailed investigations need to be carried out, applying more efficient social resources.

Keywords: modeling, susceptibility to erosion, artificial intelligence, Amazon

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Authors: Samuele Abagnato, Lucia Rigamonti

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Life-Cycle-Assessment (LCA) is an effective tool to quantify the environmental impacts of reuse models and recycling technologies for textiles. In this work, publications in the last ten years about LCA on textile waste are classified according to location, goal and scope, functional unit, waste composition, impact assessment method, impact categories, and sensitivity analysis. Twenty papers have been selected: 50% are focused only on recycling, 30% only on reuse, the 15% on both, while only one paper considers only the final disposal of the waste. It is found that reuse is generally the best way to decrease the environmental impacts of textiles waste management because of the avoided impacts of manufacturing a new item. In the comparison between a product made with recycled yarns and a product from virgin materials, in general, the first option is less impact, especially for the categories of climate change, water depletion, and land occupation, while for other categories, such as eutrophication or ecotoxicity, under certain conditions the impacts of the recycled fibres can be higher. Cultivation seems to have quite high impacts when natural fibres are involved, especially in the land use and water depletion categories, while manufacturing requires a remarkable amount of electricity, with its associated impact on climate change. In the analysis of the reuse processes, relevant importance is covered by the laundry phase, with water consumption and impacts related to the use of detergents. About the sensitivity analysis, it can be stated that one of the main variables that influence the LCA results and that needs to be further investigated in the modeling of the LCA system about this topic is the substitution rate between recycled and virgin fibres, that is the amount of recycled material that can be used in place of virgin one. Related to this, also the yield of the recycling processes has a strong influence on the results of the impact. The substitution rate is also important in the modeling of the reuse processes because it represents the number of avoided new items bought in place of the reused ones. Another aspect that appears to have a large influence on the impacts is consumer behaviour during the use phase (for example, the number of uses between two laundry cycles). In conclusion, to have a deeper knowledge of the impacts of a life-cycle approach of textile waste, further data and research are needed in the modeling of the substitution rate and of the use phase habits of the consumers.

Keywords: environmental impacts, life-cycle-assessment, textiles recycling, textiles reuse, textiles waste management

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Authors: Yuri Laevsky, Tatyana Nosova

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The phenomenon of filtration gas combustion (FGC) had been discovered experimentally at the beginning of 80’s of the previous century. It has a number of important applications in such areas as chemical technologies, fire-explosion safety, energy-saving technologies, oil production. From the physical point of view, FGC may be defined as the propagation of region of gaseous exothermic reaction in chemically inert porous medium, as the gaseous reactants seep into the region of chemical transformation. The movement of the combustion front has different modes, and this investigation is focused on the low-velocity regime. The main characteristic of the process is the velocity of the combustion front propagation. Computation of this characteristic encounters substantial difficulties because of the strong heterogeneity of the process. The mathematical model of FGC is formed by the energy conservation laws for the temperature of the porous medium and the temperature of gas and the mass conservation law for the relative concentration of the reacting component of the gas mixture. In this case the homogenization of the model is performed with the use of the two-temperature approach when at each point of the continuous medium we specify the solid and gas phases with a Newtonian heat exchange between them. The construction of a computational scheme is based on the principles of mixed finite element method with the usage of a regular mesh. The approximation in time is performed by an explicit–implicit difference scheme. Special attention was given to determination of the combustion front propagation velocity. Straight computation of the velocity as grid derivative leads to extremely unstable algorithm. It is worth to note that the term ‘front propagation velocity’ makes sense for settled motion when some analytical formulae linking velocity and equilibrium temperature are correct. The numerical implementation of one of such formulae leading to the stable computation of instantaneous front velocity has been proposed. The algorithm obtained has been applied in subsequent numerical investigation of the FGC process. This way the dependence of the main characteristics of the process on various physical parameters has been studied. In particular, the influence of the combustible gas mixture consumption on the front propagation velocity has been investigated. It also has been reaffirmed numerically that there is an interval of critical values of the interfacial heat transfer coefficient at which a sort of a breakdown occurs from a slow combustion front propagation to a rapid one. Approximate boundaries of such an interval have been calculated for some specific parameters. All the results obtained are in full agreement with both experimental and theoretical data, confirming the adequacy of the model and the algorithm constructed. The presence of stable techniques to calculate the instantaneous velocity of the combustion wave allows considering the semi-Lagrangian approach to the solution of the problem.

Keywords: filtration gas combustion, low-velocity regime, mixed finite element method, numerical simulation

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Authors: Hyuk-Jin Lee

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Even though 23 years have passed in the 21st century, nation-state and nationality-centered cultural identities are still the sentiments and ideologies that dominate the world. Nevertheless, as seen in many cases in Europe, a new perspective is needed to recognize mutual exchanges and influences and to view them as natural cultural exchanges between countries. The situation in East Asia is completely different from Europe. This is presumed to be from the long tradition of having an ethnocentric state concept for at least hundreds of years, quite different from Europe, where the concept of a nation-state was established relatively recently. In other words, unlike Europe, where active exchanges took place, the problem stems from the unique characteristics of East Asia, which has a strong tradition of finding its identity in 'difference'. Thus, it would not be hard to find cultural studies or news of the three East Asian countries emphasizing differences among one another. This applies to all cultural areas, including traditional architecture. For example, in the Korean traditional architecture field, buildings with effects from neighboring countries tend to be ignored, even if they are traditional Korean architecture. In addition to this, in the case of Korea, there seems to be one more cultural harmful aftereffect caused by the 36 years of Japanese colonial rule in the early 20th century; the obsessive filtering concept of 'it must be different from Japan'. In other words, the implicit ideological coercion that the definition of 'Korean cultural heritage' should not be influenced by exchanges with Japan may be found throughout Korean studies. The architectural and cultural aspects of the vast period of time, from the Three Kingdoms era to the beginning of Joseon, which was a period in which cultural influence exchanges with neighboring countries were relatively strong compared to the late Joseon Dynasty, also reflect the 'distorted filtering' caused by finding a repulsive identity against the Japanese colonial period. It is important to look the cultural heritage and traditions as they are inductively, not deductively. If not, we may often ignore or limit our own precious cultural heritage. Conversely, If Baekje, the ancient Korean Kingdom, helped Japan in construction and craftsmen played a big role in building the ancient temple, it would be a healthier perspective to view it as a cultural exchange rather than proudly seeing it as a cultural owner's perspective because this point of view is a proper reconstruction of our ancient and medieval Asian culture (strictly speaking, the color common to East Asia at the time). In particular, this study will examine this topic by giving specific examples from each field of Korean cultural studies. In the search for cultural identity, it would be more helpful for healthy relations between countries and collaborative research in the sensitive part of the interpretation of historical facts as well as cultural circles to minimize excessive meanings on originality and difference.

Keywords: cultural heritage identity, cultural ideology, East Asia, Korea

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Authors: Danilo A. F. Fontes, Magaly A. M.Lyra, Maria L. C. Moura, Leslie R. M. Ferraz, Salvana P. M. Costa, Amanda C. Q. M. Vieira, Larissa A. Rolim, Giovanna C. R. M. Schver, Ping I. Lee, Severino Alves-Júnior, José L. Soares-Sobrinho, Pedro J. Rolim-Neto

Abstract:

Efavirenz (EFV) is a first-choice drug in antiretroviral therapy with high efficacy in the treatment of infection by Human Immunodeficiency Virus, which causes Acquired Immune Deficiency Syndrome (AIDS). EFV has low solubility in water resulting in a decrease in the dissolution rate and, consequently, in its bioavailability. Among the technological alternatives to increase solubility, the Lamellar Double Hydroxides (LDH) have been applied in the development of systems with poorly water-soluble drugs. The use of analytical techniques such as X-Ray Diffraction (XRD), Infrared Spectroscopy (IR) and Differential Scanning Calorimetry (DSC) allowed the elucidation of drug interaction with the lamellar compounds. The objective of this work was to characterize and develop the binary systems with EFV and LDH in order to increase the solubility of the drug. The LDH-CaAl was synthesized by the method of co-precipitation from salt solutions of calcium nitrate and aluminum nitrate in basic medium. The systems EFV-LDH and their physical mixtures (PM) were obtained at different concentrations (5-60% of EFV) using the solvent technique described by Takahashi & Yamaguchi (1991). The characterization of the systems and the PM’s was performed by XRD techniques, IR, DSC and dissolution test under non-sink conditions. The results showed improvements in the solubility of EFV when associated with LDH, due to a possible change in its crystal structure and formation of an amorphous material. From the DSC results, one could see that the endothermic peak at 173°C, temperature that correspond to the melting process of EFZ in the crystal form, was present in the PM results. For the EFZ-LDH systems (with 5, 10 and 30% of drug loading), this peak was not observed. XRD profiles of the PM showed well-defined peaks for EFV. Analyzing the XRD patterns of the systems, it was found that the XRD profiles of all the systems showed complete attenuation of the characteristic peaks of the crystalline form of EFZ. The IR technique showed that, in the results of the PM, there was the appearance of one band and overlap of other bands, while the IR results of the systems with 5, 10 and 30% drug loading showed the disappearance of bands and a few others with reduced intensity. The dissolution test under non-sink conditions showed that systems with 5, 10 and 30% drug loading promoted a great increase in the solubility of EFV, but the system with 10% of drug loading was the only one that could keep substantial amount of drug in solution at different pHs.

Keywords: Efavirenz, Lamellar Double Hydroxides, Pharmaceutical Techonology, Solubility

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Authors: Tayyaba Bari, Muhammad Hamza Anjum, Samra Kanwal, Fakhera Ikram

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Osteoarthritis, a degenerative condition, affects more than 213 million individuals globally. Since articular cartilage has no or limited vessels, therefore, after deteriorating, it is unable to rejuvenate. Traditional approaches for cartilage repair, like autologous chondrocyte implantation, microfracture and cartilage transplantation are often associated with postoperative complications and lead to further degradation. Decellularized human umbilical cord has gained interest as a viable treatment for cartilage repair. Decellularization removes all cellular contents as well as debris, leaving a biologically active 3D network known as extracellular matrix (ECM). This matrix is biodegradable, non-immunogenic and provides a microenvironment for homeostasis, growth and repair. UC derived bioink function as 3D scaffolding material, not only mediates cell-matrix interactions but also adherence, proliferation and propagation of cells for 3D organoids. This study comprises different physical, chemical and biological approaches to optimize the decellularization of human umbilical cord (UC) tissues followed by the solubilization of these tissues to bioink formation. The decellularization process consisted of two cycles of freeze thaw where the umbilical cord at -20˚C was thawed at room temperature followed by dissection in small sections from 0.5 to 1cm. Similarly decellularization with ionic and non-ionic detergents Sodium dodecyl sulfate (SDS) and Triton-X 100 revealed that both concentrations of SDS i.e 0.1% and 1% were effective in complete removal of cells from the small UC tissues. The results of decellularization was further confirmed by running them on 1% agarose gel. Histological analysis revealed the efficacy of decellularization, which involves paraffin embedded samples of 4μm processed for Hematoxylin-eosin-safran and 4,6-diamidino-2-phenylindole (DAPI). ECM preservation was confirmed by Alcian Blue, and Masson’s trichrome staining on consecutive sections and images were obtained. Sulfated GAG’s content were determined by 1,9-dimethyl-methylene blue (DMMB) assay, similarly collagen quantification was done by hydroxy proline assay. This 3D bioengineered scaffold will provide a typical atmosphere as in the extracellular matrix of the tissue, which would be seeded with the mesenchymal cells to generate the desired 3D ink for in vitro and in vivo cartilage regeneration applications.

Keywords: umbilical cord, 3d printing, bioink, tissue engineering, cartilage regeneration

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Authors: Maryam Firouzmandi, Moosa Miri

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Aim and background: esthetic and structural reconstruction of anterior teeth may require the application of different restoration material. In this regard combination of direct composite veneer and ceramic crown is a common treatment option. Despite the initial matching, their long term harmony in term of optical and surface characteristics is a matter of concern. The purpose of this study is to evaluate and compare optical and surface characteristic of direct composite polished and glazed ceramic materials after exposure to tooth brush abrasion and staining solution. Materials and Methods: ten 2 mm thick disk shape specimens were prepared from IPS empress direct composite and twenty specimens from IPS e.max CAD blocks. Composite specimens and ten ceramic specimens were polished by using D&Z composite and ceramic polishing kit. The other ten specimens of ceramic were glazed with glazing liquid. Baseline measurement of roughness, CIElab coordinate, and luminance were recorded. Then the specimens underwent thermocycling, tooth brushing, and coffee staining. Afterword, the final measurements were recorded. Color coordinate were used to calculate ΔE76, ΔE00, translucency parameter, and contrast ratio. Data were analyzed by One-way ANOVA and post hoc LSD test. Results: baseline and final roughness of the study group were not different. At baseline, the order of roughness for the study group were as follows: composite < glazed ceramic < polished ceramic, but after aging, no difference. Between ceramic groups was not detected. The comparison of baseline and final luminance was similar to roughness but in reverse order. Unlike differential roughness which was comparable between the groups, changes in luminance of the glazed ceramic group was higher than other groups. ΔE76 and ΔE00 in the composite group were 18.35 and 12.84, in the glazed ceramic group were 1.3 and 0.79, and in polished ceramic were 1.26 and 0.85. These values for the composite group were significantly different from ceramic groups. Translucency of composite at baseline was significantly higher than final, but there was no significant difference between these values in ceramic groups. Composite was more translucency than ceramic at baseline and final measurement. Conclusion: Glazed ceramic surface was smoother than polished ceramic. Aging did not change the roughness. Optical properties (color and translucency) of the composite were influenced by aging. Luminance of composite, glazed ceramic, and polished ceramic decreased after aging, but the reduction in glazed ceramic was more pronounced.

Keywords: ceramic, tooth-brush abrasion, staining solution, composite resin

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Authors: Magdalena Barbara Kaziuk

Abstract:

Introduction: In December 2019, the first case of an acute infectious disease of the respiratory system caused by the SARS-CoV-2 virus was recorded in Wuhan in Central China. On March 11, 2020, the World Health Organization restrictions, among others, in the travel industry. Aim: The aim of the study was the assessment of the preparedness of European cultural institutions and catering establishments within the sanitary and epidemiological dimension during the COVID-19 pandemic by Polish tourists and their sense of safety in selected destinations. Material and methods: The study involved 300 Polish tourists (125 females, 175 males, age 46.5+/-12.9 years) who traveled during the COVID-19 pandemic to Southern European countries. 5 most popular travel destinations were selected: Italy, Austria, Greece, Croatia, and Mediterranean islands. The tourists assessed cultural institutions and catering establishments with the use of a proprietary questionnaire which concerned the preparedness regarding the sanitary and epidemiological requirements and the tourists' sense of safety. The number of respondents was deliberate - 60 persons per each country. Results: The more stringent sanitary regimes, the higher the sense of safety in the study group of females aged 45-50 (p<0.005), while the more stringent sanitary and epidemiological issues are implemented, the shorter the stay (p<0.001). Less stringent restrictions resulted in increased sense of freedom and mental rest in the group of studied males (p<0.005). Conclusions: The respondents' opinions revealed that the highest level of safety with regard to sanitary and epidemiological requirements (masks covering mouth and nose worn by both personnel and society, the necessity to present the COVID passport, the possibility to disinfect hands) was observed in Austria and Italy, while shorter length of the stay in these countries resulted from high prices, particularly in catering establishments. According to the respondents, less stringent restrictions, among others lack of the necessity to own the COVID passport, were linked to Croatia and Mediterranean islands. The sense of safety was satisfying, while the sense of freedom and mental rest was high. declared a string of COVID-19 cases a pandemic. Most countries implemented numerous sanitary and epidemiological

Keywords: sanitary and epidemiological regimes, tourist facilities, COVID-19 pandemic, sense of safety

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Authors: Hiba Naccache, Rima Hleiss

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Additive manufacturing AM or 3D printing is one of the pillars of Industry 4.0. Compared to traditional manufacturing, AM provides a prototype before production in order to optimize the design and avoid the stock market and uses strictly necessary material which can be recyclable, for the benefit of leaning towards local production, saving money, time and resources. Different types of AM exist and it has a broad range of applications across several industries like aerospace, automotive, medicine, education and else. The Laser Powder Bed Fusion (LPBF) is a metal AM technique that uses a laser to liquefy metal powder, layer by layer, to build a three-dimensional (3D) object. In industry 4.0 and aligned with the numbers 9 (Industry, Innovation and Infrastructure) and 12 (Responsible Production and Consumption) of the Sustainable Development Goals of the UNESCO 2030 Agenda, the AM’s manufacturers committed to minimizing the environmental impact by being sustainable in every production. The LPBF has several environmental advantages, like reduced waste production, lower energy consumption, and greater flexibility in creating components with lightweight and complex geometries. However, LPBF also have environmental drawbacks, like energy consumption, gas consumption and emissions. It is critical to recognize the environmental impacts of LPBF in order to mitigate them. To increase awareness and promote sustainable practices regarding LPBF, the researchers use the Elaboration Likelihood Model (ELM) theory where people from multiple universities in France and Qatar process information in two ways: peripherally and centrally. The peripheral campaigns use superficial cues to get attention, and the central campaigns provide clear and concise information. The authors created a seminar including a video showing LPBF production and a website with educational resources. The data is collected using questionnaire to test attitude about the public awareness before and after the seminar. The results reflected a great shift on the awareness toward LPBF and its impact on the environment. With no presence of similar research, to our best knowledge, this study will add to the literature on the sustainability of the LPBF production technique.

Keywords: additive manufacturing, laser powder bed fusion, elaboration likelihood model theory, sustainable development goals, education-awareness, France, Qatar, specific energy consumption, environmental impact, lightweight components

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Authors: Pavel Prochazka

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The study deals with transducers for measuring vibration displacements of rotating blade tips in turbomachines. In order to prevent major accidents with extensive economic consequences, it shows an urgent need for every low-pressure steam turbine stage being equipped with modern non-contact measuring system providing information on blade loading, damage and residual lifetime under operation. The requirement of measuring vibration and static characteristics of steam turbine blades, therefore, calls for the development and operational verification of both new types of sensors and measuring principles and methods. The task is really demanding: to measure displacements of blade tips with a resolution of the order of 10 μm by speeds up to 750 m/s, humidity 100% and temperatures up to 200 °C. While in gas turbines are used primarily capacitive and optical transducers, these transducers cannot be used in steam turbines. The reason is moisture vapor, droplets of condensing water and dirt, which disable the function of sensors. Therefore, the most feasible approach was to focus on research of electromagnetic sensors featuring promising characteristics for given blade materials in a steam environment. Following types of sensors have been developed and both experimentally and theoretically studied in the Institute of Thermodynamics, Academy of Sciences of the Czech Republic: eddy-current, Hall effect, inductive and magnetoresistive. Eddy-current transducers demand a small distance of 1 to 2 mm and change properties in the harsh environment of steam turbines. Hall effect sensors have relatively low sensitivity, high values of offset, drift, and especially noise. Induction sensors do not require any supply current and have a simple construction. The magnitude of the sensors output voltage is dependent on the velocity of the measured body and concurrently on the varying magnetic induction, and they cannot be used statically. Magnetoresistive sensors are formed by magnetoresistors arranged into a Wheatstone bridge. Supplying the sensor from a current source provides better linearity. The MR sensors can be used permanently for temperatures up to 200 °C at lower values of the supply current of about 1 mA. The frequency range of 0 to 300 kHz is by an order higher comparing to the Hall effect and induction sensors. The frequency band starts at zero frequency, which is very important because the sensors can be calibrated statically. The MR sensors feature high sensitivity and low noise. The symmetry of the bridge arrangement leads to a high common mode rejection ratio and suppressing disturbances, which is important, especially in industrial applications. The MR sensors feature high sensitivity, high common mode rejection ratio, and low noise, which is important, especially in industrial applications. Magnetoresistive transducers provide a range of excellent properties indicating their priority for displacement measurements of rotating blades in turbomachines.

Keywords: turbines, blade vibration, blade tip timing, non-contact sensors, magnetoresistive sensors

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Authors: H. Akhloufi, M. Hulscher, J. M. Prins, I. H. Van Der Sijs, D. Melles, A. Verbon

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Background: A timely switch from intravenous to oral antibiotic therapy has many advantages, such as reduced incidence of IV-line related infections, a decreased hospital length of stay and less workload for healthcare professionals with equivalent patient safety. Additionally, numerous studies have demonstrated significant decreases in costs of a timely intravenous to oral antibiotic therapy switch, while maintaining efficacy and safety. However, a considerable variation in iv to oral antibiotic switch therapy criteria has been described in literature. Here, we report the development of a set of iv to oral switch criteria that are generally applicable in all hospitals. Material/methods: A RAND-modified Delphi procedure, which was composed of 3 rounds, was used. This Delphi procedure is a widely used structured process to develop consensus using multiple rounds of questionnaires within a qualified panel of selected experts. The international expert panel was multidisciplinary and composed out of clinical microbiologists, infectious disease consultants and clinical pharmacists. This panel of 19 experts appraised 6 major intravenous to oral antibiotic switch therapy criteria and operationalized these criteria using 41 measurable conditions extracted from the literature. The procedure to select a concise set of iv to oral switch criteria included 2 questionnaire rounds and a face-to-face meeting. Results: The procedure resulted in the selection of 16 measurable conditions, which operationalize 6 major intravenous to oral antibiotic switch therapy criteria. The following 6 major switch therapy criteria were selected: (1) Vital signs should be good or improving when bad. (2) Signs and symptoms related to the infection have to be resolved or improved. (3) The gastrointestinal tract has to be intact and functioning. (4) The oral route should not be compromised. (5) Absence of contra-indicated infections. (6) An oral variant of the antibiotic with good bioavailability has to exist. Conclusions: This systematic stepwise method which combined evidence and expert opinion resulted in a feasible set of 6 major intravenous to oral antibiotic switch therapy criteria operationalized by 16 measurable conditions. This set of early antibiotic iv to oral switch criteria can be used in daily practice in all adult hospital patients. Future use in audits and as rules in computer assisted decision support systems will lead to improvement of antimicrobial steward ship programs.

Keywords: antibiotic resistance, antibiotic stewardship, intravenous to oral, switch therapy

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Authors: Heather Warfield, Brad Genereux

Abstract:

Military personnel encounter a number of challenges when separating from military service to include career uncertainty, relational/family dynamics, trauma as a result of military experiences, reconceptualization of identity, and existential issues related to purpose, meaning making and framing of the military experience(s). Embedded within military culture are well-defined rites of passage and a significant sense of belonging. Consequently, transition out of the military can result in the loss of such rites of passage and belongingness. However, a pilgrimage journey can provide the time and space to engage in a new rite of passage, to construct a new pilgrim identity, and a to develop deep social relationships that lead to a sense of belongingness to a particular pilgrim community as well as to the global community of pilgrims across numerous types of pilgrimage journeys. The aims of the current paper are to demonstrate the rationale for why pilgrimage journeys are particularly significant for military veterans, provide an overview of an innovative program that facilitates the Camino de Santiago pilgrimage for military veterans, and discusses the lessons learned from the initial pilot project of a recently established program. Veterans on the Camino (VOC) is an emerging nongovernmental organization in the USA. Founded by a military veteran, after leaving his military career, the primary objective of the organization is to facilitate healing for veterans via the Camino de Santiago pilgrimage journey. As part of the program, participants complete a semi-structured interview at three time points – pre, during, and post journey. The interview items are based on ongoing research by the principal investigator and address such constructs as meaning-making, wellbeing, therapeutic benefits and transformation. In addition, program participants complete The Sources of Meaning and Meaning in Life Questionnaire (SoMe). The pilot program occurred in the spring of 2017. Five participants were selected after an extensive application process and review by a three-person selection board. The selection criteria included demonstrated compatibility with the program objectives (i.e., prior military experience, availability for a 40 day journey, and awareness of the need for a transformational intervention). The participants were connected as a group through a private Facebook site and interacted with one another for several months prior to the pilgrimage. Additionally, the participants were interviewed prior to beginning the pilgrimage, at one point during the pilgrimage and immediately following the conclusion of the pilgrimage journey. The interviews yielded themes related to loss, meaning construction, renewed hope in humanity, and a commitment to future goals. The lessons learned from this pilot project included a confirmation of the need for such a program, a need for greater focus on logistical details, and the recognition that the pilgrimage experience needs to continue in some manner once the veterans return home.

Keywords: pilgrimage, healing, military veterans, Camino de Santiago

Procedia PDF Downloads 275

Authors: A. Díaz-Roa, P. I. Silva Junior, F. J. Bello

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Sarconesiopsis magellanica (Diptera: Calliphoridae) is a medically important necrophagous fly which is used for establishing the post-mortem interval. Dipterous maggots release diverse proteins and peptides contained in larval excretion and secretion (ES) products playing a key role in digestion. The most important mechanism for combating infection using larval therapy depends on larval ES. These larvae are protected against infection by a diverse spectrum of antimicrobial peptides (AMPs), one already known like lucifensin. Special interest in these peptides has also been aroused regarding understanding their role in wound healing since they degrade necrotic tissue and kill different bacteria during larval therapy. The action of larvae on wounds occurs through 3 mechanisms of action: removal of necrotic tissue, stimulation of granulation tissue, and antibacterial action of larval ES. Some components of the ES include calcium, urea, allantoin ammonium bicarbonate and reducing the viability of Gram positive and Gram negative bacteria. The Lucilia sericata fly larvae have been the most used, however, we need to evaluate new species that could potentially be similar or more effective than fly above. This study was thus aimed at identifying and characterizing S. magellanica AMPs contained in ES products for the first time and compared them with the common fly used L. sericata. These products were obtained from third-instar larvae taken from a previously established colony. For the first analysis, ES fractions were separate by Sep-Pak C18 disposable columns (first step). The material obtained was fractionated by RP-HPLC by using Júpiter C18 semi-preparative column. The products were then lyophilized and their antimicrobial activity was characterized by incubation with different bacterial strains. The first chromatographic analysis of ES from L. sericata gives 6 fractions with antimicrobial activity against Gram-positive bacteria Micrococus luteus, and 3 fractions with activity against Gram-negative bacteria Pseudomonae aeruginosa while the one from S. magellanica gaves 1 fraction against M. luteus and 4 against P. aeruginosa. Maybe one of these fractions could correspond to the peptide already known from L. sericata. These results show the first work for supporting further experiments aimed at validating S. magellanica use in larval therapy. We still need to search if we find some new molecules, by making mass spectrometry and ‘de novo sequencing’. Further studies are necessary to identify and characterize them to better understand their functioning.

Keywords: antimicrobial peptides, larval therapy, Lucilia sericata, Sarconesiopsis magellanica

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Authors: Yeo Kyeong Lee, Hae Won Min, Ji Yeon Kang, Hee Sun Kim, Yeong Soo Shin

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Fire incidents have been steadily increased over the last year according to national emergency management agency of South Korea. Even though most of the fire incidents with property damage have been occurred in building, rehabilitation has not been properly done with consideration of structure safety. Therefore, this study aims at evaluating rehabilitation effects on fire damaged normal strength concrete beams through experiments and finite element analyses. For the experiments, reinforced concrete beams were fabricated having designed concrete strength of 21 MPa. Two different cover thicknesses were used as 40 mm and 50 mm. After cured, the fabricated beams were heated for 1hour or 2hours according to ISO-834 standard time-temperature curve. Rehabilitation was done by removing the damaged part of cover thickness and filling polymeric mortar into the removed part. Both fire damaged beams and rehabilitated beams were tested with four point loading system to observe structural behaviors and the rehabilitation effect. To verify the experiment, finite element (FE) models for structural analysis were generated using commercial software ABAQUS 6.10-3. For the rehabilitated beam models, integrated temperature-structural analyses were performed in advance to obtain geometries of the fire damaged beams. In addition to the fire damaged beam models, rehabilitated part was added with material properties of polymeric mortar. Three dimensional continuum brick elements were used for both temperature and structural analyses. The same loading and boundary conditions as experiments were implemented to the rehabilitated beam models and non-linear geometrical analyses were performed. Test results showed that maximum loads of the rehabilitated beams were 8~10% higher than those of the non-rehabilitated beams and even 1~6 % higher than those of the non-fire damaged beam. Stiffness of the rehabilitated beams were also larger than that of non-rehabilitated beams but smaller than that of the non-fire damaged beams. In addition, predicted structural behaviors from the analyses also showed good rehabilitation effect and the predicted load-deflection curves were similar to the experimental results. From this study, both experiments and analytical results demonstrated good rehabilitation effect on the fire damaged normal strength concrete beams. For the further, the proposed analytical method can be used to predict structural behaviors of rehabilitated and fire damaged concrete beams accurately without suffering from time and cost consuming experimental process.

Keywords: fire, normal strength concrete, rehabilitation, reinforced concrete beam

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Authors: Omaima A. Sharaf, Tarek A. Moussa, Said M. Badr El-Din, H. Moawad

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Background: Polycyclic aromatic hydrocarbons (PAHs) pose great environmental and human health concerns for their widespread occurrence, persistence, and carcinogenic properties. PAHs releases due to anthropogenic activities to the wider environment have led to higher concentrations of these contaminants than would be expected from natural processes alone. This may result in a wide range of environmental problems that can accumulate in agricultural ecosystems, which threatened to become a negative impact on sustainable agricultural development. Thus, this study aimed to evaluate the physico-chemical, and microbial properties of the compost leachate (CL) to assess its role as nutrient and microbial source (biostimulation/bioaugmentation) for developing a cost-effective bioremediation technology for PAHs contaminated sites. Material and Methods: PAHs-degrading bacteria were isolated from CL that was collected from a composting site located in central Scotland, UK. Isolation was carried out by enrichment using phenanthrene (PHR), pyrene (PYR) and benzo(a)pyrene (BaP) as the sole source of carbon and energy. The isolates were characterized using a variety of phenotypic and molecular properties. Six different isolates were identified based on the difference in morphological and biochemical tests. The efficiency of these isolates in PAHs utilization was assessed. Further analysis was performed to define taxonomical status and phylogenic relation between the most potent PAHs-utilizing bacterial strains and other standard strains, using molecular approach by partial 16S rDNA gene sequence analysis. Results indicated that the 16S rDNA sequence analysis confirmed the results of biochemical identification, as both of biochemical and molecular identification of the isolates assigned them to Bacillus licheniformis, Pseudomonas aeruginosa, Alcaligenes faecalis, Serratia marcescens, Enterobacter cloacae and Providenicia which were identified as the prominent PAHs-utilizers isolated from CL. Conclusion: This study indicates that the CL samples contain a diverse population of PAHs-degrading bacteria and the use of CL may have a potential for bioremediation of PAHs contaminated sites.

Keywords: polycyclic aromatic hydrocarbons, physico-chemical analyses, compost leachate, microbial and biochemical analyses, phylogenic relations, 16S rDNA sequence analysis

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Authors: Deborah Eric, Abbas Ahmad Khan

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Lead halide perovskites quantum dots have attracted immense scientific and technological interest for successful photovoltaic applications because of their remarkable optoelectronic properties. In this paper, we have simulated CsMAPbI3-xBrx based quantum dots to implement their use in intermediate band solar cells (IBSC). These types of materials exhibit optical and electrical properties distinct from their bulk counterparts due to quantum confinement. The conceptual framework provides a route to analyze the electronic properties of quantum dots. This layer of quantum dots optimizes the position and bandwidth of IB that lies in the forbidden region of the conventional bandgap. A three-dimensional MAPbI3 quantum dot (QD) with geometries including spherical, cubic, and conical has been embedded in the CsPbBr3 matrix. Bound energy wavefunction gives rise to miniband, which results in the formation of IB. If there is more than one miniband, then there is a possibility of having more than one IB. The optimization of QD size results in more IBs in the forbidden region. One band time-independent Schrödinger equation using the effective mass approximation with step potential barrier is solved to compute the electronic states. Envelope function approximation with BenDaniel-Duke boundary condition is used in combination with the Schrödinger equation for the calculation of eigen energies and Eigen energies are solved for the quasi-bound states using an eigenvalue study. The transfer matrix method is used to study the quantum tunneling of MAPbI3 QD through neighbor barriers of CsPbI3. Electronic states are computed using Schrödinger equation with effective mass approximation by considering quantum dot and wetting layer assembly. Results have shown the varying the quantum dot size affects the energy pinning of QD. Changes in the ground, first, second state energies have been observed. The QD is non-zero at the center and decays exponentially to zero at boundaries. Quasi-bound states are characterized by envelope functions. It has been observed that conical quantum dots have maximum ground state energy at a small radius. Increasing the wetting layer thickness exhibits energy signatures similar to bulk material for each QD size.

Keywords: perovskite, intermediate bandgap, quantum dots, miniband formation

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Authors: Ekta, G. K. Darbha

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Nanotechnology offers the potential of simultaneously increasing efficiency as compared to their bulk material as well as reducing harmful environmental impacts of pesticides in field of agriculture. The term nanopesticide covers different pesticides that are cumulative of several surfactants, polymers, metal ions, etc. of nanometer size ranges from 1-1000 nm and exhibit abnormal behavior (high efficacy and high specific surface area) of nanomaterials. Commercial formulations of pesticides used by farmers nowadays cannot be used effectively due to a number of problems associated with them. For example, more than 90% of applied formulations are either lost in the environment or unable to reach the target area required for effective pest control. Around 20−30% of pesticides are lost through emissions. A number of factors (application methods, physicochemical properties of the formulations, and environmental conditions) can influence the extent of loss during application. It is known that among various formulations, polymer-based formulations show the greatest potential due to their greater efficacy, slow release and protection against premature degradation of active ingredient as compared to other commercial formulations. However, the nanoformulations can have a significant effect on the fate of active ingredient as well as may release some new ingredients by reacting with existing soil contaminants. Environmental fate of these newly generated species is still not explored very well which is essential to field scale experiments and hence a lot to be explored in the field of environmental fate, nanotoxicology, transport properties and stability of such formulations. In our preliminary work, we have synthesized polymer based nanoformulation of commercially used weedicide atrazine. Atrazine belongs to triazine class of herbicide, which is used in the effective control of seed germinated dicot weeds and grasses. It functions by binding to the plastoquinone-binding protein in PS-II. Plant death results from starvation and oxidative damage caused by breakdown in electron transport system. The stability of the suspension of nanoformulation containing herbicide has been evaluated by considering different parameters like polydispersity index, particle diameter, zeta-potential under different environmental relevance condition such as pH range 4-10, temperature range from 25°C to 65°C and stability of encapsulation also have been studied for different amount of added polymer. Morphological characterization has been done by using SEM.

Keywords: atrazine, nanoformulation, nanopesticide, nanotoxicology

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Authors: Anderson Rocha-Buelvas, Jaqueline Mena Huertas, Edith Burbano Rosero, Arsenio Hidalgo Troya, Mauricio Casas Cruz

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COVID-19 is a disruptive pandemic for the public health and economic system of whole countries, including Colombia. Nariño Department is the southwest of the country and draws attention to being on the border with Ecuador, constantly facing demographic transition affecting infections between countries. In Nariño, the early routine diagnosis of SARS-CoV-2, which can be handled at BSL-2, has affected the transmission dynamics of COVID-19. However, new emerging and re-emerging viruses with biological flexibility classified as a Risk Group 3 agent can take advantage of epidemiological opportunities, generating the need to increase clinical diagnosis, mainly in border regions between countries. The overall objective of this project was to assure the quality of the analytical process in the diagnosis of high biological risk pathogens in Nariño by building a laboratory that includes biosafety level (BSL)-2 and (BSL)-3 containment zones. The delimitation of zones was carried out according to the Verification Tool of the National Health Institute of Colombia and following the standard requirements for the competence of testing and calibration laboratories of the International Organization for Standardization. This is achieved by harmonization of methods and equipment for effective and durable diagnostics of the large-scale spread of highly pathogenic microorganisms, employing negative-pressure containment systems and UV Systems in accordance with a finely controlled electrical system and PCR systems as new diagnostic tools. That increases laboratory capacity. Protection in BSL-3 zones will separate the handling of potentially infectious aerosols within the laboratory from the community and the environment. It will also allow the handling and inactivation of samples with suspected pathogens and the extraction of molecular material from them, allowing research with pathogens with high risks, such as SARS-CoV-2, Influenza, and syncytial virus, and malaria, among others. The diagnosis of these pathogens will be articulated across the spectrum of basic, applied, and translational research that could receive about 60 daily samples. It is expected that this project will be articulated with the health policies of neighboring countries to increase research capacity.

Keywords: medical laboratory science, SARS-CoV-2, public health surveillance, Colombia

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Authors: Wujian Han

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In the process of human interaction and communication, speech act verbs are considered to be the most active component and the main means for information transmission, and are also taken as an indication of the structure of linguistic behavior. The theoretical value and practical significance of such everyday built-in metalanguage have long been recognized. This paper, which is part of a bigger study, is aimed to provide useful insights for a more precise and systematic application to speech act verbs translation between English and Chinese, especially with regard to the degree to which generic integrity is maintained in the practice of translation of legal documents. In this study, the corpus, i.e. Chinese legal texts and their English translations, English legal texts, ordinary Chinese texts, and ordinary English texts, serve as a testing ground for examining contrastively the usage of English and Chinese directive speech act verbs in legal genre. The scope of this paper is relatively wide and essentially covers all directive speech act verbs which are used in ordinary English and Chinese, such as order, command, request, prohibit, threat, advice, warn and permit. The researcher, by combining the corpus methodology with a contrastive perspective, explored a range of characteristics of English and Chinese directive speech act verbs including their semantic, syntactic and pragmatic features, and then contrasted them in a structured way. It has been found that there are similarities between English and Chinese directive speech act verbs in legal genre, such as similar semantic components between English speech act verbs and their translation equivalents in Chinese, formal and accurate usage of English and Chinese directive speech act verbs in legal contexts. But notable differences have been identified in areas of difference between their usage in the original Chinese and English legal texts such as valency patterns and frequency of occurrences. For example, the subjects of some directive speech act verbs are very frequently omitted in Chinese legal texts, but this is not the case in English legal texts. One of the practicable methods to achieve adequacy and conciseness in speech act verb translation from Chinese into English in legal genre is to repeat the subjects or the message with discrepancy, and vice versa. In addition, translation effects such as overuse and underuse of certain directive speech act verbs are also found in the translated English texts compared to the original English texts. Legal texts constitute a particularly valuable material for speech act verb study. Building up such a contrastive picture of the Chinese and English speech act verbs in legal language would yield results of value and interest to legal translators and students of language for legal purposes and have practical application to legal translation between English and Chinese.

Keywords: contrastive analysis, corpus-based, directive speech act verbs, legal texts, translation between English and Chinese

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Authors: Majid Eslami

Abstract:

Functionally graded materials (FGMs) exhibit heterogeneous microstructures in which the composition and properties gently change in specified directions. The common type of FGMs consist of a metal in which ceramic particles are distributed with a graded concentration. There are many processing routes for FGMs. An important group of these methods is casting techniques (gravity or centrifugal). However, the main problem of casting molten metal slurry with dispersed ceramic particles is a destructive chemical reaction between these two phases which deteriorates the properties of the materials. In order to overcome this problem, in the present investigation a suspension of 6061 aluminum and alumina powders in a liquid polymer was used as the starting material and subjected to centrifugal force for making FGMs. The size rang of these powders was 45-63 and 106-125 μm. The volume percent of alumina in the Al/Al2O3 powder mixture was in the range of 5 to 20%. PMMA (Plexiglas) in different concentrations (20-50 g/lit) was dissolved in toluene and used as the suspension liquid. The glass mold contaning the suspension of Al/Al2O3 powders in the mentioned liquid was rotated at 1700 rpm for different times (4-40 min) while the arm length was kept constant (10 cm) for all the experiments. After curing the polymer, burning out the binder, cold pressing and sintering , cylindrical samples (φ=22 mm h=20 mm) were produced. The density of samples before and after sintering was quantified by Archimedes method. The results indicated that by using the same sized alumina and aluminum powders particles, FGM sample can be produced by rotation times exceeding 7 min. However, by using coarse alumina and fine alumina powders the sample exhibits step concentration. On the other hand, using fine alumina and coarse alumina results in a relatively uniform concentration of Al2O3 along the sample height. These results are attributed to the effects of size and density of different powders on the centrifugal force induced on the powders during rotation. The PMMA concentration and the vol.% of alumina in the suspension did not have any considerable effect on the distribution of alumina particles in the samples. The hardness profiles along the height of samples were affected by both the alumina vol.% and porosity content. The presence of alumina particles increased the hardness while increased porosity reduced the hardness. Therefore, the hardness values did not show the expected gradient in same sample. The sintering resulted in decreased porosity for all the samples investigated.

Keywords: FGM, powder metallurgy, centrifugal method, polymeric suspension

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