Search results for: contact resistance

Authors: Ankita Jadon, Sidi Souvi, Nathalie Girault, Denis Petitprez

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Safety requirements for Generation IV nuclear reactor designs, especially the new generation sodium-cooled fast reactors (SFR) require a risk-informed approach to model severe accidents (SA) and their consequences in case of outside release. In SFRs, aerosols are produced during a core disruptive accident when primary system sodium is ejected into the containment and burn in contact with the air; producing sodium aerosols. One of the key aspects of safety evaluation is the in-containment sodium aerosol behavior and their interaction with fission products. The study of the effects of sodium fires is essential for safety evaluation as the fire can both thermally damage the containment vessel and cause an overpressurization risk. Besides, during the fire, airborne fission product first dissolved in the primary sodium can be aerosolized or, as it can be the case for fission products, released under the gaseous form. The objective of this work is to study the interactions between sodium aerosols and fission products (Iodine, toxic and volatile, being the primary concern). Sodium fires resulting from an SA would produce aerosols consisting of sodium peroxides, hydroxides, carbonates, and bicarbonates. In addition to being toxic (in oxide form), this aerosol will then become radioactive. If such aerosols are leaked into the environment, they can pose a danger to the ecosystem. Depending on the chemical affinity of these chemical forms with fission products, the radiological consequences of an SA leading to containment leak tightness loss will also be affected. This work is split into two phases. Firstly, a method to theoretically understand the kinetics and thermodynamics of the heterogeneous reaction between sodium aerosols and fission products: I2 and HI are proposed. Ab-initio, density functional theory (DFT) calculations using Vienna ab-initio simulation package are carried out to develop an understanding of the surfaces of sodium carbonate (Na2CO3) aerosols and hence provide insight on its affinity towards iodine species. A comprehensive study of I2 and HI adsorption, as well as bicarbonate formation on the calculated lowest energy surface of Na2CO3, was performed which provided adsorption energies and description of the optimized configuration of adsorbate on the stable surface. Secondly, the heterogeneous reaction between (I2)g and Na2CO3 aerosols were investigated experimentally. To study this, (I2)g was generated by heating a permeation tube containing solid I2, and, passing it through a reaction chamber containing Na2CO3 aerosol deposit. The concentration of iodine was then measured at the exit of the reaction chamber. Preliminary observations indicate that there is an effective uptake of (I2)g on Na2CO3 surface, as suggested by our theoretical chemistry calculations. This work is the first step in addressing the gaps in knowledge of in-containment and atmospheric source term which are essential aspects of safety evaluation of SFR SA. In particular, this study is aimed to determine and characterize the radiological and chemical source term. These results will then provide useful insights for the developments of new models to be implemented in integrated computer simulation tool to analyze and evaluate SFR safety designs.

Keywords: iodine adsorption, sodium aerosols, sodium cooled reactor, DFT calculations, sodium carbonate

Procedia PDF Downloads 195

Authors: Ashleigh Dawn Moeller

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This is a comparative case study which examines the language attitudes and behaviors of descendants of Volga German immigrants in North America and how these attitudes combined with surrounding social conditions have caused their heritage language to develop differently within each community. Of particular interest for this study are the accounts of second- and third-generation descendants in Oregon, Kansas, and North Dakota regarding their parents’ and grandparents’ attitudes toward their language and how this correlates with the current sentiment as well as visibility of their heritage language and culture. This study discusses the point at which cultural identity could diverge from language identity and what elements play a role in this development, establishing the potential for environments (linguistic landscapes) which uphold their heritage yet have detached from the language itself. Emigrating from Germany in the 1700s, these families settled for over a hundred years along the Volga Region of Imperial Russia. Subsequently, many descendants of these settlers immigrated to the Americas in the 1800-1900s. Identifying neither as German nor Russian, they called themselves Wolgadeutche (Volga Germans). During their time in Russia, the German language was maintained relatively homogenously, yet the use and status of their heritage language diverged considerably upon settlement across the Americas. Data shows that specific conditions, such as community isolation, size, religion, location as well as language policy established prior to and following the Volga German immigration to North America have had a substantial impact on the maintenance of their heritage language—causing complete loss in some areas and peripheral use or even full rebirth in others. These past conditions combined with the family accounts correlate directly with the general attitudes and ideologies of the descendants toward their heritage language. Data also shows that in many locations, despite a strong presence of German within the linguistic landscape, minimal to no German is spoken nor understood; the attitude toward the language is indifferent while a staunch holding to the heritage is maintained and boasted. Data for this study was gathered from historical accounts, archived records and newspapers, and published biographies as well as from formal interviews with second- and third-generation descendants of Volga German immigrants conducted in Oregon and Kansas. Through the interviews, members of the community have shared and provided their family genealogies as well as biographies published by family members. These have helped to trace their relatives back to specific locations, thus allowing for comparisons within the same families residing in distinctly different areas of North America. This study is part of a larger ongoing project which researches the immigration of Volga and Black Sea Germans to North America and diachronically examines the over-arching sociological factors which have directly impacted the maintenance, loss, or rebirth of their heritage language. This project follows specific families who settled in areas of Colorado, Kansas, Nebraska, Illinois, Minnesota, North and South Dakota, Saskatchewan, and Manitoba, and who later had relatives move west to areas of Oregon and Washington State. Interviews for the larger project will continue into the following year.

Keywords: heritage language, immigrant language, language change, language contact, linguistic landscape, Volga Germans, Wolgadeutsche

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Authors: Fstemeh Rais Esmaili, Ehsan Ranjbar

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Pedestrian streets as one type of urban public spaces have an important role in improving the quality of urban life. In Iran, planning and designing of pedestrian streets is in its primary steps. In spite of starting this approach in Iran, and designing several pedestrian streets, there are still not organized studies about quality assessment of pedestrian streets. As a result, the strength and weakness points of the initial experiences have not been utilized. This inattention to quality assessment have caused designing pedestrian streets to be limited to just vehicles traffic control and preliminary actions like paving; so that, special potentials of pedestrian streets for creating social, livable and dynamic public spaces have not been used. This article, as an organized study about quality assessment of pedestrian streets in Iran, tries to reach two main goals: first, introducing a framework for quality assessment of pedestrian streets in Iran, and second, creating a context for improving the quality of pedestrian streets especially for further experiences. The main research methods are description and context analyzing. With respect to comparative analysis of ideas about quality, considering international and local case studies and analyzing existing condition of Saf Pedestrian Street, a particular model for quality assessment has been introduced. In this model, main components and assessment criteria have been presented. On the basis of this model, questionnaire and checklist for assessment have been prepared. The questionnaire and interview have been used to assess qualities which are in direct contact with people and the checklist has been used for analyzing visual qualities by authors through observation. Some results of questionnaire and checklist show that 7 of 11 primary components, diversity, flexibility, cleanness, legibility and imaginably, identity, livability, form and physical setting are rated low and very low in quality degree. Three components, efficiency, comfort and distinctiveness, have medium and low quality degree and one component, access, linkage and permeability has high quality degree. Therefore, based on implemented analyzing process, Saf Pedestrian Street needs to be improved and these quality improvement priorities are determined based on presented criteria. Adaption of final results with existing condition illustrates the shortage of services for satisfying user’s needs, inflexibility and impossibility of using spaces in various times, lack of facilities for different climatic conditions, lack of facilities such as drinking fountain, inappropriate designing of existing urban furniture like garbage cans, and creating pollution and unsuitable view, lack of visual attractions, neglecting disabled persons in designing entrances, shortage of benches and their undesirable designing, lack of vegetation, absence of special characters making it different from other streets, preventing people taking part in the space causing lack of affiliation, lack of appropriate elements for leisure time and lack of exhilaration in the space. On the other hand, these results present high access and permeability, high safety, less sound pollution and more relief, comfortable movement along the way due to suitable pavement and economic efficiency, as the strength points of Saf pedestrian street.

Keywords: pedestrian streets, quality assessment, quality criteria, Saf Pedestrian Street

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Authors: L. Sánchez-Abella, I. Loinaz, H-J. Grande, D. Dupin

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Aseptic loosening remains as the principal cause of revision in total hip arthroplasty (THA). For long-term implantations, submicron particles are generated in vivo due to the inherent wear of the prosthesis. When this occurs, macrophages undergo phagocytosis and secretion of bone resorptive cytokines inducing osteolysis, hence loosening of the implanted prosthesis. Therefore, new technologies are required to reduce the wear of the bearing materials and hence increase the life-span of the prosthesis. Our strategy focuses on surface modification of the bearing materials with a hydrophilic coating based on cross-linked water-soluble (meth)acrylic monomers to improve their tribological behavior. These coatings are biocompatible, with high swelling capacity and antifouling properties, mimicking the properties of natural cartilage, i.e. wear resistance with a permanent hydrated layer that prevents prosthesis damage. Cartilage mimicking based coatings may be also used to protect medical device surfaces from damage and scratches that will compromise their integrity and hence their safety. However, there are only a few reports on the mechanical and tribological characteristics of this type of coatings. Clear beneficial advantages of this coating have been demonstrated in different conditions and different materials, such as Ultra-high molecular weight polyethylene (UHMWPE), Polyethylene (XLPE), Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK), cobalt-chromium (CoCr), Stainless steel, Zirconia Toughened Alumina (ZTA) and Alumina. Using routine tribological experiments, the wear for UHMWPE substrate was decreased by 75% against alumina, ZTA and stainless steel. For PEEK-CFR substrate coated, the amount of material lost against ZTA and CrCo was at least 40% lower. Experiments on hip simulator allowed coated ZTA femoral heads and coated UHMWPE cups to be validated with a decrease of 80% of loss material. Further experiments on hip simulator adding abrasive particles (1 micron sized alumina particles) during 3 million cycles, on a total of 6 million, demonstrated a decreased of around 55% of wear compared to uncoated UHMWPE and uncoated XLPE. In conclusion, CIDETEC‘s hydrogel coating technology is versatile and can be adapted to protect a large range of surfaces, even in abrasive conditions.

Keywords: cartilage, hydrogel, hydrophilic coating, joint

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Authors: Leonardo Parra, Daniel Martínez, Jorge Pizarro, Fernando Ortega, Manuel Chacón-Fuentes, Andrés Quiroz

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Control of Dalaca pallens or blackworms, one of the most important hypogeous pest in grassland in southern Chile, is based on the use of broad-spectrum insecticides such as organophosphates and pyrethroids. However, the rapid development of insecticide resistance in field populations of this insect and public concern over the environmental impact of these insecticides has resulted in the search for other control methods. Specifically, the use of endophyte fungi for controlling pest has emerged as an interesting and promising strategy. Endophytes from ryegrass (Lolium perenne), establish a biotrophic relationship with the host, defined as mutualistic symbiosis. The plant-fungi association produces alkaloids where peramine is the main toxic substance against Listronotus bonariensis, the most important epigean pest of ryegrass. Nevertheless, the effect of peramina on others pest insects, such as D. pallens, to our knowledge has not been studied, and also its possible metabolization in the body of the larvae. Therefore, we addressed the following research question: Do larvae of D. pallens store peramine after consumption of ryegrass endophyte infected (E+)? For this, specimens of blackworms were fed with ryegrass plant of seven experimental lines and one commercial cultivar endophyte free (E-) sown at the Instituto de Investigaciones Agropecuarias Carillanca (Vilcún, Chile). Once the feeding period was over, ten larvae of each treatment were examined. Individuals were dissected, and their gut was removed to exclude any influence of remaining material. The rest of the larva's body was dried at 60°C by 24-48 h and ground into a fine powder using a mortar. 25 mg of dry powder was transferred to a microcentrifuge tube and extracted in 1 mL of a mixture of methanol:water:formic acid. Then, the samples were centrifuged at 16,000 rpm for 3 min, and the supernatant was colected and injected in the liquid chromatography of high resolution (HPLC). The results confirmed the presence of peramine in the larva's body of D. pallens. The insects that fed the experimental lines LQE-2 and LQE-6 were those where peramine was present in high proportion (0.205 and 0.199 ppm, respectively); while LQE-7 and LQE-3 obtained the lowest concentrations of the alkaloid (0.047 and 0.053 ppm, respectively). Peramine was not detected in the insects when the control cultivar Jumbo (E-) was tested. These results evidenced the storage and metabolism of peramine during consumption of the larvae. However, the effect of this alkaloid present in 'future ryegrass cultivars' (LQE-2 and LQE-6) on the performance and survival of blackworms must be studied and confirmed experimentally.

Keywords: blackworms, HPLC, alkaloid, pest

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Authors: Yung-Chih Kuo, I-Hsin Wang

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Catanionic solid lipid nanoparticles (CASLNs) with surface wheat germ agglutinin (WGA) and lactoferrin (Lf) were formulated for entrapping and releasing etoposide (ETP), crossing the blood–brain barrier (BBB), and inhibiting the growth of glioblastoma multiforme (GBM). Microemulsified ETP-CASLNs were modified with WGA and Lf for permeating a cultured monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes and for treating malignant U87MG cells. Experimental evidence revealed that an increase in the concentration of catanionic surfactant from 5 μM to 7.5 μM reduced the particle size. When the concentration of catanionic surfactant increased from 7.5 μM to 12.5 μM, the particle size increased, yielding a minimal diameter of WGA-Lf-ETP-CASLNs at 7.5 μM of catanionic surfactant. An increase in the weight percentage of BW from 25% to 75% enlarged WGA-Lf-ETP-CASLNs. In addition, an increase in the concentration of catanionic surfactant from 5 to 15 μM increased the absolute value of zeta potential of WGA-Lf-ETP-CASLNs. It was intriguing that the increment of the charge as a function of the concentration of catanionic surfactant was approximately linear. WGA-Lf-ETP-CASLNs revealed an integral structure with smooth particle contour, displayed a lighter exterior layer of catanionic surfactant, WGA, and Lf and showed a rigid interior region of solid lipids. A variation in the concentration of catanionic surfactant between 5 μM and 15 μM yielded a maximal encapsulation efficiency of ETP ata 7.5 μM of catanionic surfactant. An increase in the concentration of Lf/WGA decreased the grafting efficiency of Lf/WGA. Also, an increase in the weight percentage of ETP decreased its encapsulation efficiency. Moreover, the release rate of ETP from WGA-Lf-ETP-CASLNs reduced with increasing concentration of catanionic surfactant, and WGA-Lf-ETP-CASLNs at 12.5 μM of catanionic surfactant exhibited a feature of sustained release. The order in the viability of HBMECs was ETP-CASLNs ≅ Lf-ETP-CASLNs ≅ WGA-Lf-ETP-CASLNs > ETP. The variation in the transendothelial electrical resistance (TEER) and permeability of propidium iodide (PI) was negligible when the concentration of Lf increased. Furthermore, an increase in the concentration of WGA from 0.2 to 0.6 mg/mL insignificantly altered the TEER and permeability of PI. When the concentration of Lf increased from 2.5 to 7.5 μg/mL and the concentration of WGA increased from 2.5 to 5 μg/mL, the enhancement in the permeability of ETP was minor. However, 10 μg/mL of Lf promoted the permeability of ETP using Lf-ETP-CASLNs, and 5 and 10 μg/mL of WGA could considerably improve the permeability of ETP using WGA-Lf-ETP-CASLNs. The order in the efficacy of inhibiting U87MG cells was WGA-Lf-ETP-CASLNs > Lf-ETP-CASLNs > ETP-CASLNs > ETP. As a result, WGA-Lf-ETP-CASLNs reduced the TEER, enhanced the permeability of PI, induced a minor cytotoxicity to HBMECs, increased the permeability of ETP across the BBB, and improved the antiproliferative efficacy of U87MG cells. The grafting of WGA and Lf is crucial to control the medicinal property of ETP-CASLNs and WGA-Lf-ETP-CASLNs can be promising colloidal carriers in GBM management.

Keywords: catanionic solid lipid nanoparticle, etoposide, glioblastoma multiforme, lactoferrin, wheat germ agglutinin

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Authors: Natasha Gabriella, Josef-Peter Schöggl, Alfred Posch

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Being a mature industry, pulp and paper industry (PPI) possess strength points coming from its existing infrastructure, technology know-how, and abundant availability of biomass. However, the declining trend of the wood-based products sales sends a clear signal to the industry to transform its business model in order to increase its profitability. With the emerging global attention on bio-based economy and circular economy, coupled with the low price of fossil feedstock, the PPI starts to integrate biorefinery as a value-added business model to keep the industry’s competitiveness. Nonetheless, biorefinery as an innovation exposes the PPI with some barriers, of which the uncertainty of the promising product becomes one of the major hurdles. This study aims to assess factors that affect the diffusion and development of forest biorefinery in the PPI, including drivers, barriers, advantages, disadvantages, as well as the most promising bio-based products of forest biorefinery. The study examines the identified factors according to the layer of business environment, being the macro-environment, industry, and strategic group level. Besides, an overview of future state of the identified factors is elaborated as to map necessary improvements for implementing forest biorefinery. A two-phase Delphi method is used to collect the empirical data for the study, comprising of an online-based survey and interviews. Delphi method is an effective communication tools to elicit ideas from a group of experts to further reach a consensus of forecasting future trends. Collaborating a total of 50 experts in the panel, the study reveals that influential factors are found in every layers of business of the PPI. The politic dimension is apparent to have a significant influence for tackling the economy barrier while reinforcing the environmental and social benefits in the macro-environment. In the industry level, the biomass availability appears to be a strength point of the PPI while the knowledge gap on technology and market seem to be barriers. Consequently, cooperation with academia and the chemical industry has to be improved. Human resources issue is indicated as one important premise behind the preceding barrier, along with the indication of the PPI’s resistance towards biorefinery implementation as an innovation. Further, cellulose-based products are acknowledged for near-term product development whereas lignin-based products are emphasized to gain importance in the long-term future.

Keywords: forest biorefinery, pulp and paper, bio-based product, Delphi method

Procedia PDF Downloads 251

Authors: Z. Sun

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Health communication is essential in promoting healthy lifestyles, managing disease conditions, and eventually reducing health disparities. The key elements of successful health communication always include the development of communication strategies to engage people in thinking about their health, inform them about healthy choices, persuade them to adopt safe and healthy behaviours, and eventually achieve public health objectives. The use of 'Narrative' is recognised as a kind of health communication strategy to enhance personal and public health due to its potential persuasive effect in motivating and supporting individuals change their beliefs and behaviours by inviting them into a narrative world, breaking down their cognitive and emotional resistance and enhance their acceptance of the ideas portrayed in narratives. Meanwhile, the popularity of social media has provided a novel means of communication for both healthcare stakeholders, and a special group of active social media users (influencers) have started playing a pivotal role in providing health ‘solutions’. Such individuals are often referred to as ‘influencers’ because of their central position in the online communication system and the persuasive effect their actions may have on audiences. They may have established a positive rapport with their audience, earned trust and credibility in a specific area, and thus, their audience considers the information they delivered to be authentic and influential. To our best knowledge, to date, there is no published research that examines the effect of diabetes narratives presented by social media influencers and their impacts on health-related outcomes. The primary aim of this study is to investigate the diabetes narratives presented by social media influencers in the UK because of the new dimension they bring to health communication and the potential impact they may have on audiences' health outcomes. This study is situated within the interpretivist and narrative paradigms. A mixed methodology combining both quantitative and qualitative approaches has been adopted. Qualitative data has been derived to provide a better understanding of influencers’ personal experiences and how they construct meanings and make sense of their world, while quantitative data has been accumulated to identify key social media influencers in the UK and measure the impact of diabetes narratives on audiences. Twitter has been chosen as the social media platform to initially identify key influencers. Two groups of participants are the top 10 key social media influencers in the UK and 100 audiences of each influencer, which means a total of 1000 audiences have been invited. This paper is going to discuss, first of all, the background of the research under the context of health communication; Secondly, the necessity and contribution of this research; then, the major research questions being explored; and finally, the methods to be used.

Keywords: diabetes, health communication, narratives, social media influencers

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Authors: Amenah Dhannoon, Ciaran Martin Hurley, Laura Wrafter, Podraic J. Regan

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Introduction: The COVID-19 pandemic continues to present unprecedented challenges for healthcare systems. This has resulted in the pragmatic shift in the practice of plastic surgery units worldwide. During this period, many units reported a significant fall in urgent melanoma referrals, leading to patients presenting with advanced disease requiring more extensive surgery and inferior outcomes. Our objective was to evaluate our unit's experience with both non-invasive and invasive melanoma during the COVID-19 pandemic and characterize our experience and contrast it to that experienced by our neighbors in the UK, mainland Europe and North America. Methods: a retrospective chart review was performed on all patients diagnosed with invasive and non-invasive cutaneous melanoma between March to December of 2019 (control) compared to 2020 (COVID-19 pandemic) in a single plastic surgery unit in Ireland. Patient demographics, referral source, surgical procedures, tumour characteristics, radiological findings, oncological therapies and follow-up were recorded. All data were anonymized and stored in Microsoft Excel. Results: A total of 589 patients were included in the study. Of these, 314 (53%) with invasive melanoma, compared to 275 (47%) with the non-invasive disease. Overall, more patients were diagnosed with both invasive and non-invasive melanoma in 2020 than in 2019 (p<0.05). However, significantly longer waiting times in 2020 (64 days) compared to 2019 (28 days) (p<0.05), with the majority of the referral being from GP in 2019 (83%) compared to 61% in 2020. Positive sentinel lymph node were higher in 2019 at 56% (n=28) compared to 24% (n=22) in 2020. There was no statistically significant difference in the tutor characteristics or metastasis status. Discussion: While other countries have noticed a fall in the melanoma diagnosis. Our units experienced a higher number of disease diagnoses. This can be due to multiple reasons. In Ireland, the government reached an early agreement with the private sector to continue elective surgery on an urgent basis in private hospitals. This allowed access to local anesthetic procedures and local skin cancer cases were triaged to non-COVID-19 provider centers. Our unit also adapted a fast, effective and minimal patient contact strategy for triaging skin cancer based on telemedicine. Thirdly, a skin cancer nurse specialist maintained patient follow-ups and triaging a dedicated email service. Finally, our plastic surgery service continued to maintain a virtual complex skin cancer multidisciplinary team meeting during the pandemic, ensuring local clinical governance has adhered to each clinical case. Conclusion: Our study highlights that with the prompt efficient restructuring of services, we could reserve successful management of skin cancer even in the most devastating times. It is important to reflect on the success during the pandemic and emphasize the importance of preparation for a potentially difficult future

Keywords: malignant melanoma, skin cancer, COVID-19, triage

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Authors: Z. C. Dlamini, R. L. S. Langa, A. I. Okoh, O. A. Aiyegoro

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The indiscriminate usage of antibiotics in swine production have consequential outcomes; such as development of bacterial resistance to prophylactic antibiotics and possibility of antibiotic residues in animal products. The use of probiotics appears to be the most effective procedure with positive metabolic nutritional implications. The aim of this study was to investigate the efficacy of probiotic bacteria (Lactobacillus reuteri ZJ625, Lactobacillus reuteri VB4, Lactobacillus salivarius ZJ614 and Streptococcus salivarius NBRC13956) administered as direct-fed microorganisms in weaned piglets. 45 weaned piglets blocked by weight were dived into 5 treatments groups: diet with antibiotic, diet with no-antibiotic and no probiotic, and diet with probiotic and diet with combination of probiotics. Piglets performance was monitored during the trials. Faecal and Ileum samples were collected for microbial count analysis. Blood samples were collected from pigs at the end of the trial, for analysis of haematological, biochemical and IgG stimulation. The data was analysed by Split-Plot ANOVA using SAS statistically software (SAS 9.3) (2003). The difference was observed between treatments for daily weight and feed conversion ratio. No difference was observed in analysis of faecal samples in regards with bacterial counts, difference was observed in ileums samples with enteric bacteria colony forming unit being lower in P2 treatment group as compared with lactic acid and total bacteria. With exception of globulin and albumin, biochemistry blood parameters were not affected, likewise for haematology, only basophils and segmented neutrophils were differed by having higher concentration in NC treatment group as compared with other treatment groups. Moreover, in IgG stimulation analysis, difference was also observed, with P2 treatment group having high concentration of IgG in P2 treatment group as compared to other groups. The results of this study suggest that probiotics have a beneficial effect on growth performances, blood parameters and IgG stimulation of pigs, most effective when they are administered in synergy form. This means that it is most likely that these probiotics will offer a significant benefit in pig farming by reducing risk of morbidity and mortality and produce quality meat that is more affordable to poorer communities, and thereby enhance South African pig industry’s economy. In addition, these results indicate that there is still more research need to be done on probiotics in regards with, i.e. dosage, shelf life and mechanism of action.

Keywords: antibiotics, biochemistry, haematology, IgG-stimulation, microbial count, probiotics

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Authors: Lillian Musila, Valerie Oundo, Daniel Erwin, Willie Sang

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Staphylococcus aureus infections are a major cause of nosocomial infections in Kenya. Methicillin resistant S. aureus (MRSA) infections are a significant burden to public health and are associated with considerable morbidity and mortality. At a hospital in Western Kenya two clusters of MRSA cases emerged within short periods of time. In this study we explored whether these clusters represented a nosocomial outbreak by characterizing the isolates using phenotypic and molecular assays and examining epidemiological data to identify possible transmission patterns. Specimens from the site of infection of the subjects were collected, cultured and S. aureus isolates identified phenotypically and confirmed by APIStaph™. MRSA were identified by cefoxitin disk screening per CLSI guidelines. MRSA were further characterized based on their antibiotic susceptibility patterns and spa gene typing. Characteristics of cases with MRSA isolates were compared with those with MSSA isolated around the same time period. Two cases of MRSA infection were identified in the two week period between 21 April and 4 May 2015. A further 2 MRSA isolates were identified on the same day on 7 September 2015. The antibiotic resistance patterns of the two MRSA isolates in the 1st cluster of cases were different suggesting that these were distinct isolates. One isolate had spa type t2029 and the other had a novel spa type. The 2 isolates were obtained from urine and an open skin wound. In the 2nd cluster of MRSA isolates, the antibiotic susceptibility patterns were similar but isolates had different spa types: one was t037 and the other a novel spa type different from the novel MRSA spa type in the first cluster. Both cases in the second cluster were admitted into the hospital but one infection was community- and the other hospital-acquired. Only one of the four MRSA cases was classified as an HAI from an infection acquired post-operatively. When compared to other S. aureus strains isolated within the same time period from the same hospital only one spa type t2029 was found in both MRSA and non-MRSA strains. None of the cases infected with MRSA in the two clusters shared any common epidemiological characteristic such as age, sex or known risk factors for MRSA such as prolonged hospitalization or institutionalization. These data suggest that the observed MRSA clusters were multi strain clusters and not an outbreak of a single strain. There was no clear relationship between the isolates by spa type suggesting that no transmission was occurring within the hospital between these cluster cases but rather that the majority of the MRSA strains were circulating in the community. There was high diversity of spa types among the MRSA strains with none of the isolates sharing spa types. Identification of disease clusters in space and time is critical for immediate infection control action and patient management. Spa gene typing is a rapid way of confirming or ruling out MRSA outbreaks so that costly interventions are applied only when necessary.

Keywords: cluster, Kenya, MRSA, spa typing

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Authors: Faheemah N. Mustafaa, Tamarie Macon, Tabbye Chavous

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A major concern of university leaders worldwide is how to create environments where students from diverse racial/ethnic, national, and cultural backgrounds can thrive. Over the past decade or so in the United States, African American women have done exceedingly well in terms of college enrollment, academic performance, and completion. However, the relative academic successes of African American women in higher education has in some ways overshadowed social challenges many Black women continue to encounter on college campuses in the United States. Within predominantly White institutions (PWIs) in particular, there is consistent evidence that many Black students experience racially hostile climates. However, research studies on racial climates within PWIs have mostly focused on cross-sectional comparisons of minority and majority group experiences, and few studies have examined campus racial climate in relation to short- and longer-term well-being. One longitudinal study reported that African American women’s psychological well-being was positively related to their comfort in cross-racial interactions (a concept closely related to campus climate). Thus, our primary research question was: Do African American women’s perceptions of campus climate (tension and positive association) during their freshman year predict their reports of psychological distress and well-being (self-acceptance) during their sophomore year? Participants were part of a longitudinal survey examining African American college students’ academic identity development, particularly in Science, Technology, Engineering, and Mathematics (STEM) fields. The final subsample included 134 self-identified African American/Black women enrolled in PWIs. Accounting for background characteristics (mother’s education, family income, interracial contact, and prior levels of outcomes), we employed hierarchical regression to examine relationships between campus racial climate during freshman year and psychological adjustment one year later. Both regression models significantly predicted African American women’s psychological outcomes (for distress, F(7,91)= 4.34, p < .001; and for self-acceptance, F(7,90)= 4.92, p < .001). Although none of the controls were significant predictors, perceptions of racial tension on campus were associated with both distress and self-acceptance. More perceptions of tension were related to African American women’s greater psychological distress the following year (B= 0.22, p= .01). Additionally, racial tension predicted later self-acceptance in the expected direction: Higher first-year reports of racial tension were related to less positive attitudes toward the self during the sophomore year (B= -0.16, p= .04). However, perceptions that it was normative for Black and White students to socialize on campus (or positive association scores) were unrelated to psychological distress or self-acceptance. Findings highlight the relevance of examining multiple facets of campus racial climate in relation to psychological adjustment, with possible emphasis on the import of racial tension on African American women’s psychological adjustment. Results suggest that negative dimensions of campus racial climate may have lingering effects on psychological well-being, over and above more positive aspects of climate. Thus, programs targeted toward improving student relations on campus should consider addressing cross-racial tensions.

Keywords: higher education, psychological adjustment, university climate, university students

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Authors: Selvaprakash Ramalingam, Rabi N. Sahoo, Dharmendra Saraswat, A. Kumar, Rajeev Ranjan, Joydeep Mukerjee, Viswanathan Chinnasamy, K. K. Chaturvedi, Sanjeev Kumar

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Rice is one of the most important staple food crops in the world. Among the various diseases that affect rice crops, rice blast is particularly significant, causing crop yield and economic losses. While the plant has defense mechanisms in place, such as chemical indicators (proteins, salicylic acid, jasmonic acid, ethylene, and azelaic acid) and resistance genes in certain varieties that can protect against diseases, susceptible varieties remain vulnerable to these fungal diseases. Early prediction of rice blast (RB) disease is crucial, but conventional techniques for early prediction are time-consuming and labor-intensive. Hyperspectral remote sensing techniques hold the potential to predict RB disease at its asymptomatic stage. In this study, we aimed to demonstrate the prediction of RB disease at the asymptomatic stage using non-imaging hyperspectral ASD spectroradiometer under controlled laboratory conditions. We applied statistical spectral discrimination theory to identify unknown spectra of M. Oryzae, the fungus responsible for rice blast disease. The infrared (IR) region was found to be significantly affected by RB disease. These changes may result in alterations in the absorption, reflection, or emission of infrared radiation by the affected plant tissues. Our research revealed that the protein spectrum in the IR region is impacted by RB disease. In our study, we identified strong correlations in the region (Amide group - I) around X 1064 nm and Y 1300 nm with the Lambda / Lambda derived spectra methods for protein detection. During the stages when the disease is developing, typically from day 3 to day 5, the plant's defense mechanisms are not as effective. This is especially true for the PB-1 variety of rice, which is highly susceptible to rice blast disease. Consequently, the proteins in the plant are adversely affected during this critical time. The spectral contour plot reveals the highly correlated spectral regions 1064 nm and Y 1300 nm associated with RB disease infection. Based on these spectral sensitivities, we developed new spectral disease indices for predicting different stages of disease emergence. The goal of this research is to lay the foundation for future UAV and satellite-based studies aimed at long-term monitoring of RB disease.

Keywords: rice blast, asymptomatic stage, spectral sensitivity, IR

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Authors: Sara Khamseh, Elahe Sharifi

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321 alloy steel is austenitic stainless steel with high oxidation resistance and is commonly used to fabricate heat exchangers and steam generators. However, the low hardness and weak tribological performance can cause dangerous failures during industrial operations. The well-designed protective coatings on 321 alloy steel surfaces with high hardness and good tribological performance can guarantee their safe applications. The surface protection of metal substrates using protective coatings showed high efficiency in prevailing these problems. Carbon-based multicomponent coatings, such as metal-added amorphous carbon coatings, are crucially necessary because of their remarkable mechanical and tribological performances. In the current study, (Nb: Si: a-C) multicomponent coatings (a-C: amorphous carbon) were coated on 321 alloys using a balanced magnetron (BM) sputtering system at room temperature. The effects of the Si/Nb ratio on microstructure, mechanical and tribological characteristics of (Nb: Si: a-C) composite coatings were investigated. The XRD and Raman analysis results showed that the coatings formed a composite structure of cubic diamond (C-D), NbC, and graphite-like carbon (GLC). The NbC phase's abundance decreased when the C-D phase's affluence increased with an increasing Si/Nb ratio. The coatings' indentation hardness and plasticity index (H³/E² ratio) increased with an increasing Si/Nb ratio. The better mechanical properties of the coatings with higher Si content can be attributed to the higher cubic diamond (C-D) content. The cubic diamond (C-D) is a challenging phase and can positively affect the mechanical performance of the coatings. It is well documented that in hard protective coatings, Si encourages amorphization. In addition, THE studies showed that Nb and Mo can act as a catalyst for nucleation and growth of hard cubic (C-D) and hexagonal (H-D) diamond phases in a-C coatings. In the current study, it seems that fully arranged nanocomposite coatings contain hard C-D and NbC phases that embedded in the amorphous carbon (GLC) phase is formed. This unique structure decreased grain boundary density and defects and resulted in high hardness and H³/E² ratio. Moreover, the COF and wear rate of the coatings decreased with increasing Si/Nb ratio. This can be attributed to the good mechanical properties of the coatings and the formation of graphite-like carbon (GLC) structure with lamellae arrangement in the coatings. The complex and self-lubricant coatings are successfully formed on the surface of 321 alloys. The results of the present study clarified that Si addition to (Nb: a-C) coatings improve the mechanical and tribological performance of the coatings on 321 alloy.

Keywords: COF, mechanical properties, microstructure, (Nb: Si: a-C) coatings, Wear rate

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Authors: Shirly Bar-Lev, Michal Morag

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Cults are usually thought of as suppressive organizations, where creativity is systematically stifled. Except for few scholars, creativity in cults remains an uncharted terrain (Boeri and Pressley, 2010). This paperfocuses on how cult members sought real and imaginary spaces to express themselves and even used their bodies as canvases on which to assert their individuality, resistance, devotion, pain, and anguish. We contend that cult members’ creativity paves their way out of the cult. This paper is part of a larger study into the experiences of former members of cults and cult-like NewReligiousMmovements (NRM). The research is based on in-depth interviews conducted with thirtyIsraeli men and women, aged 24 to 50, who either joined an NRM or were born into one. Their stories reveal that creativity is both emplaced and embedded in power relations. That is why Foucault’s idea of Heterotopia and Winnicott’s idea of the battle between True and False self canbenefit our understanding of how cult members creatively assert their autonomy over their bodies and thoughts while in the cult. Cults’ operate on a complex tension between submission and autonomy. On the one hand, they act as heterotopias byallowing for a ‘simultaneousmythic and real contestation of the space in which we live. Ascounter-hegemonic sites, they serve as‘the greatest reserve of theimagination’, to use Foucault’s words. Cults definitely possesselements of mystery, danger, and transgression where an alternative social ordering can emerge. On the other hand, cults are set up to format alternative identities. Often, the individuals who inhibit these spaces look for spiritual growth, self-reflection, and self-actualization. They might willingly relinquish autonomy over vast aspects of their lives in pursuit of self-improvement. In any case, cultsclaim the totality of their members’ identities and absolute commitment and compliance with the cult’s regimes. It, therefore, begs the question how the paradox between autonomy and submissioncan spur instances of creativity. How can cult members escape processes of performative regulation to assert their creative self? Both Foucault and Winnicott recognize the possibility of an authentic self – one that is spontaneous and creative. Both recognize that only the true self can feel real andmust never comply. Both note the disciplinary regimes that push the true self into hiding, as well as the social and psychological mechanisms that individuals develop to protect their true self. But while Foucault spoke of the power of critic as a way of salvaging the true self, Winnicott spoke of recognition and empathy - feeling known by others. Invitinga dialogue between the two theorists can yield a productive discussion on how cult members assert their ‘true self’ to cultivate a creative self within the confines of the cult.

Keywords: cults, creativity, heterotopia, true and false self

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Authors: Hilal T. Sasmazel, Seda Surucu

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Skin tissue engineering is a promising field for the treatment of skin defects using scaffolds. This approach involves the use of living cells and biomaterials to restore, maintain, or regenerate tissues and organs in the body by providing; (i) larger surface area for cell attachment, (ii) proper porosity for cell colonization and cell to cell interaction, and (iii) 3-dimensionality at macroscopic scale. Recent studies on this area mainly focus on fabrication of scaffolds that can closely mimic the natural extracellular matrix (ECM) for creation of tissue specific niche-like environment at the subcellular scale. Scaffolds designed as ECM-like architectures incorporating into the host with minimal scarring/pain and facilitate angiogenesis. This study is related to combining of synthetic PCL and natural chitosan polymers to form 3D PCL/Chitosan core-shell structures for skin tissue engineering applications. Amongst the polymers used in tissue engineering, natural polymer chitosan and synthetic polymer poly(ε-caprolactone) (PCL) are widely preferred in the literature. Chitosan has been among researchers for a very long time because of its superior biocompatibility and structural resemblance to the glycosaminoglycan of bone tissue. However, the low mechanical flexibility and limited biodegradability properties reveals the necessity of using this polymer in a composite structure. On the other hand, PCL is a versatile polymer due to its low melting point (60°C), ease of processability, degradability with non-enzymatic processes (hydrolysis) and good mechanical properties. Nevertheless, there are also several disadvantages of PCL such as its hydrophobic structure, limited bio-interaction and susceptibility to bacterial biodegradation. Therefore, it became crucial to use both of these polymers together as a hybrid material in order to overcome the disadvantages of both polymers and combine advantages of those. The scaffolds here were fabricated by using electrospinning technique and the characterizations of the samples were done by contact angle (CA) measurements, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-Ray Photoelectron spectroscopy (XPS). Additionally, gas permeability test, mechanical test, thickness measurement and PBS absorption and shrinkage tests were performed for all type of scaffolds (PCL, chitosan and PCL/chitosan core-shell). By using ImageJ launcher software program (USA) from SEM photographs the average inter-fiber diameter values were calculated as 0.717±0.198 µm for PCL, 0.660±0.070 µm for chitosan and 0.412±0.339 µm for PCL/chitosan core-shell structures. Additionally, the average inter-fiber pore size values exhibited decrease of 66.91% and 61.90% for the PCL and chitosan structures respectively, compare to PCL/chitosan core-shell structures. TEM images proved that homogenous and continuous bead free core-shell fibers were obtained. XPS analysis of the PCL/chitosan core-shell structures exhibited the characteristic peaks of PCL and chitosan polymers. Measured average gas permeability value of produced PCL/chitosan core-shell structure was determined 2315±3.4 g.m-2.day-1. In the future, cell-material interactions of those developed PCL/chitosan core-shell structures will be carried out with L929 ATCC CCL-1 mouse fibroblast cell line. Standard MTT assay and microscopic imaging methods will be used for the investigation of the cell attachment, proliferation and growth capacities of the developed materials.

Keywords: chitosan, coaxial electrospinning, core-shell, PCL, tissue scaffold

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Authors: Radek Novotny, Michal Novak, Daniela Marusakova, Monika Sipova, Hugo Fuentes, Peter Borst

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This research has been conducted within the European HORIZON 2020 project ECC-SMART. The main objective is to assess whether it is feasible to design and develop a small modular reactor (SMR) that would be cooled by supercritical water (SCW). One of the main objectives for material research concerns the corrosion of the candidate cladding materials. The experimental part has been conducted in support of the qualification procedure of the future SCW-SMR constructional materials. The last objective was to identify the gaps in current norms and guidelines. Apart from corrosion, resistance testing of candidate materials stresses corrosion cracking susceptibility tests have been performed in supercritical water. This paper describes part of these tests, in particular, those slow strain rate tensile loading applied for tangential ring shape specimens of two candidate materials, Alloy 800H and 310S stainless steel. These ring tensile tests are one the methods used for tensile testing of nuclear cladding. Here full circular heads with dimensions roughly equal to the inner diameter of the sample and the gage sections are placed in the parallel direction to the applied load. Slow strain rate tensile tests have been conducted in 380 or 500oC supercritical water applying two different elongation rates, 1x10-6 and 1x10-7 s-1. The effect of temperature and dissolved oxygen content on the SCC susceptibility of Alloy 800H and 310S stainless steel was investigated when two different temperatures and concentrations of dissolved oxygen were applied in supercritical water. The post-fracture analysis includes fractographic analysis of the fracture surfaces using SEM as well as cross-sectional analysis on the occurrence of secondary cracks. Assessment of the effect of environment and dissolved oxygen content was by comparing to the results of the reference tests performed in air and N2 gas overpressure. The effect of high temperature on creep and its role in the initiation of SCC was assessed as well. It has been concluded that the applied test method could be very useful for the investigation of stress corrosion cracking susceptibility of candidate cladding materials in supercritical water.

Keywords: stress corrosion cracking, ring tensile tests, super-critical water, alloy 800H, 310S stainless steel

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Authors: Tasleem Zafar, Jiwan Sidhu

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Introduction: Chickpea flour is known to offer many benefits to diabetic persons, especially in maintaining their blood sugar levels in the acceptable range. Under this project we have studied the chemical composition and antioxidant capacity of white flour (WF), whole wheat flour (WWF) and chickpea flour (BF), in addition to the effect of replacement of WF and WWF with BF on the rheological characteristics of these flour blends, with the ultimate objective of producing acceptable quality flat as well as pan-bread for the diabetic consumers. Methods: WF and WWF were replaced with BF ranging from 0 to 40%, to investigate its effect on the rheological properties and functionality of blended flour dough using farinograph, viscoamylograph, mixograph and falling number apparatus as per the AACC standard methods. Texture Profile Analysis (TPA) was carried on the WF, WWF, and their blends with BF using Stable Micro System Texture Analyzer. Effect of certain additives, such as freeze-dried amla fruit powder (Phyllanthus emblica L.), guar gum, and xanthan gum on the dough rheological properties were also studied. Results: Freeze-dried amla fruit powder was found to be very rich in ascorbic acid and other phenolics having higher antioxidant activity. A decreased farinograph water absorption, increased dough development time, higher mixing tolerance index (i.e., weakening of dough), decreased resistance to extension, lower ratio numbers were obtained when the replacement with BF was increased from 0 to 40%. The BF gave lower peak viscosity, lower paste breakdown, and lower setback values when compared with WF. The falling number values were significantly lower in WWF (meaning higher α-amylase activity) than both the WF and BF. Texture Profile Analysis (TPA) carried on the WF, WWF, and their blends with BF showed significant variations in hardness and compressibility values, dough becoming less hard and less compressible when the replacement of WF and WWF with BF was increased from 0 to 40%. Conclusions: To overcome the deleterious effects of adding BF to WF and WWF on the rheological properties will be an interesting challenge when good quality pan bread and Arabic flatbread have to be commercially produced in a bakery. Use of freeze-dried amla fruit powder, guar gum, and xanthan gum did show some promise to improve the mixing characteristics of WF, WWF, and their blends with BF, and these additives are expected to be useful in producing an acceptable quality flat as well as pan-bread on a commercial scale.

Keywords: wheat flour, chickpea flour, amla fruit, rheology

Procedia PDF Downloads 128

Authors: Charlotte Jeavons, Charitini Stavropoulous, Nicolas Drey

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Background: Over one-third of five-year-olds and almost half of all eight-year-olds in the UK have obvious caries experience that can be detected by visual screening techniques. School-based caries preventions programs to apply fluoride varnish to young children’s teeth operate in many areas in the UK. Their aim is to reduce dental caries in children. The Department of Health guidance (2009) on consent states information must be provided to parents to enable informed autonomous decision-making prior to any treatment involving their young children. Fluoride varnish schemes delivered in primary schools use letters for this purpose. Parents are expected to return these indicating their consent or refusal. A large proportion of parents do not respond. In the absence of positive consent, these children are excluded from the program. Non-response is more common in deprived areas creating inequality. The reason for this is unknown. The consent process used is underpinned by the ethical theory of deontology that is prevalent in clinical dentistry and widely accepted in bio-ethics. Objective: To investigate parents’ views, understanding and experience of the fluoride varnish program taking place in their child’s school, including their views about the practical consent arrangements. Method: Schools participating in the fluoride varnish scheme operating in Enfield, North London, were asked to take part. Parents with children in nursery, reception, or year one were invited to participate via semi-structured interviews and focus groups. Thematic analysis was conducted. Findings: 40 parents were recruited from eight schools. The global theme of ‘trust’ was identified as the strongest influence on parental responses. Six themes were identified; protecting children from harm is viewed by parents as their role, parents have the capability to decide but lack confidence, sharing responsibility for their child’s oral health with the State is welcomed by a parent, existing relationships within parents’ social networks strongly influences consent decisions, official dental information is not communicated effectively, sending a letter to parents’ and excluding them from meeting dental practitioners is ineffective. The information delivered via a letter was not strongly identified by parents as influencing their response. Conclusions: Personal contact with the person(s) providing information and requesting consent has a greater impact on parental consent responses than written information provided alone. This demonstrates that traditional bio-ethical ideas about rational decision-making where emotions are transcended and interference is not justified unless preventing harm to an unaware person are outdated. Parental decision-making is relational and the consent process should be adapted to reflect this. The current system that has a deontology view of decision making at its core impoverishes parental autonomy and may, ultimately, increase dental inequalities as a result.

Keywords: consent, decision, ethics, fluoride, parents

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Authors: Sonia Amariei, Ionut Avramia, Florin Ursachi, Ancuta Chetrariu, Ancuta Petraru

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The food industry is one of the major generators of plastic waste derived from conventional synthetic petroleum-based polymers, which are non-biodegradable, used especially for packaging. These packaging materials, after the food is consumed, accumulate serious environmental concerns due to the materials but also to the organic residues that adhere to them. It is the concern of specialists, researchers to eliminate problems related to conventional materials that are not biodegradable or unnecessary plastic and replace them with biodegradable and edible materials, supporting the common effort to protect the environment. Even though environmental and health concerns will cause more consumers to switch to a plant-based diet, most people will continue to add more meat to their diet. The paper presents the possibility of replacing the polyethylene packaging from the surface of the trays for meat preparations with biodegradable packaging obtained from biopolymers. During the storage of meat products may occur deterioration by lipids oxidation and microbial spoilage, as well as the modification of the organoleptic characteristics. For this reason, different compositions of polymer mixtures and film conditions for obtaining must be studied to choose the best packaging material to achieve food safety. The compositions proposed for packaging are obtained from alginate, agar, starch, and glycerol as plasticizers. The tensile strength, elasticity, modulus of elasticity, thickness, density, microscopic images of the samples, roughness, opacity, humidity, water activity, the amount of water transferred as well as the speed of water transfer through these packaging materials were analyzed. A number of 28 samples with various compositions were analyzed, and the results showed that the sample with the highest values for hardness, density, and opacity, as well as the smallest water vapor permeability, of 1.2903E-4 ± 4.79E-6, has the ratio of components as alginate: agar: glycerol (3:1.25:0.75). The water activity of the analyzed films varied between 0.2886 and 0.3428 (aw< 0.6), demonstrating that all the compositions ensure the preservation of the products in the absence of microorganisms. All the determined parameters allow the appreciation of the quality of the packaging films in terms of mechanical resistance, its protection against the influence of light, the transfer of water through the packaging. Acknowledgments: This work was supported by a grant of the Ministry of Research, Innovation, and Digitization, CNCS/CCCDI – UEFISCDI, project number PN-III-P2-2.1-PED-2019-3863, within PNCDI III.

Keywords: meat products, alginate, agar, starch, glycerol

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Authors: Pichaya Poonlarp, Danai Boonyakiat, C. Chuamuangphan, M. Chanta

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Current consumers’ behavior trends have changed towards more health awareness, the well-being of society and interest of nature and environment. The Royal Project Foundation is, therefore, well aware of organic agriculture. The project only focused on using natural products and utilizing its highland biological merits to increase resistance to diseases and insects for the produce grown. The project also brought in basic knowledge from a variety of available research information, including, but not limited to, improvement of soil fertility and a control of plant insects with biological methods in order to lay a foundation in developing and promoting farmers to grow quality produce with a high health safety. This will finally lead to sustainability for future highland agriculture and a decrease of chemical use on the highland area which is a source of natural watershed. However, there are still shortcomings of the postharvest management in term of quality and losses, such as bruising, rottenness, wilting and yellowish leaves. These losses negatively affect the maintenance and a shelf life of organic vegetables. Therefore, it is important that a research study of the appropriate and effective postharvest management is conducted for an individual organic vegetable to minimize product loss and find root causes of postharvest losses which would contribute to future postharvest management best practices. This can be achieved through surveys and data collection from postharvest processes in order to conduct analysis for causes of postharvest losses of organic pak-choi, baby pak-choi, and choy sum. Consequently, postharvest losses reduction strategies of organic vegetables can be achieved. In this study, postharvest losses of organic pak choi, baby pak-choi, and choy sum were determined at each stage of the supply chain starting from the field after harvesting, at the Development Center packinghouse, at Chiang Mai packinghouse, at Bangkok packing house and at the Royal Project retail shop in Chiang Mai. The results showed that postharvest losses of organic pak-choi, baby pak-choi, and choy sum were 86.05, 89.05 and 59.03 percent, respectively. The main factors contributing to losses of organic vegetables were due to mechanical damage and underutilized parts and/or short of minimum quality standard. Good practices had been developed after causes of losses were identified. Appropriate postharvest handling and management, for example, temperature control, hygienic cleaning, and reducing the duration of the supply chain, postharvest losses of all organic vegetables should be able to remarkably reduced postharvest losses in the supply chain.

Keywords: postharvest losses, organic vegetables, handling improvement, shelf life, supply chain

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Authors: Marie-Josee Lavallee

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Adorno’s reputation as an abstract and pessimistic thinker who indulged in a critic of capitalist society and culture without bothering himself with opening prospects for change, and who has no interest in political activism, recently begun to be questioned. This paper, which has a twofold objective, will push revisionist readings a step further by putting forward the thesis that revolutionary praxis has been an enduring concern for Adorno, surfacing throughout his entire work. On the other hand, it will hold that his understanding of the relationships between theory and praxis, which will be explained by referring to Ernst Bloch’s distinction between the warm and cold currents of Marxism, can help to interpret the paralysis of revolutionary practice in our own time under a new light. Philosophy and its tasks have been an enduring topic of Adorno’s work from the 1930s to Negativ Dialektik. The writings in which he develops these ideas stand among his most obscure and abstract so that their strong ties to the political have remained mainly overlooked. Adorno’s undertaking of criticizing and ‘redeeming’ philosophy and metaphysics is inseparable from a care for retrieving the capacity to act in the world and to change it. Philosophical problems are immanent to sociological problems, and vice versa, he underlines in his Metaphysik. Begriff and Problem. The issue of truth cannot be severed from the contingent context of a given idea. As a critical undertaking extracting its contents from reality, which is what philosophy should be from Adorno's perspective, the latter has the potential to fully reveal the reification of the individual and consciousness resulting from capitalist economic and cultural domination, thus opening the way to resistance and revolutionary change. While this project, according to his usual method, is sketched mainly in negative terms, it also exhibits positive contours which depict a socialist society. Only in the latter could human suffering end, and mutilated individuals experiment with reconciliation in an authentic way. That Adorno’s continuous plea for philosophy’s self-critic and renewal hides an enduring concern for revolutionary praxis emerges clearly from a careful philosophical analysis of his writings on philosophy and a selection of his sociological work, coupled with references to his correspondences. This study points to the necessity of a serious re-evaluation of Adorno’s relationship to the political, which will impact on the interpretation of his whole oeuvre, is much needed. In the second place, Adorno's dialectical conception of theory and praxis is enlightening for our own time, since it suggests that we are experiencing a phase of creative latency rather an insurmountable impasse.

Keywords: Frankfurt school, philosophy and revolution, revolutionary praxis, Theodor W. Adorno

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Authors: Tahzeeb Mahreen

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Distance education refers to giving instruction in which students are remote from the institution and once in a while go to formal demonstration classes, and teaching sessions. Segments of media, for example, radio, TV, PC and Internet and so on are the assets and method for correspondence being utilized as a part of learning material by many open and distance learning institutions. Media has a great part in maximizing the learning opportunities thus enabling distance education, a mode of increased literacy rate of the country. This study goes for analyzing how media had affected distance education through its different mediums. The objectives of the study were (i) to determine the direct impact of media on distance education? (ii) To know how media effects distance education pedagogy (iii) To find out how media works to increase student’s achievement. Literature-based methodology was used, and books, peer-reviewed articles, press reports and internet-based materials were studied as a result. By using descriptive qualitative research analysis, the researcher has interpreted that distance education programs are progressively utilizing mixes of media to convey training that has a positive impact on learning along with a few challenges. In addition, the perception of the researcher varied depending on the programs of distance learning but generally believed that electronic media were moderately more supportive in enhancing the overall performance of the learners. It was concluded that the intellectual style, identity qualities, and self-expectations are the three primary enhanced areas in a student’s educational life in distance education programs. It was portrayed that a comprehension of how individual learners approach learning may make it workable for the distance educator to see an example of learning styles and arrange or modify course presentations through media. Moreover, it is noticed that teaching in distance education address the developing role of the instructor, the requirement for diminishing resistance as conventional teachers utilize remove conveyance frameworks lastly, staff state of mind toward the utilization of innovation. Furthermore, the results showed that media had assumed its part to make distance learning educators more dynamic, capable and concerned about their individual works. The study also indicated a high positive relationship between the media available at study centers and media used by the distance education. The challenge pointed out by the researcher was the clash of distance and time with communication as the life situations of every learner are varied. Recommendations included the realization of the duty of distance learning instructor to help students understand the effective use of media for their study lessons and also to develop online learning communities to be in instant connection with the students.

Keywords: distance education, education, media, teaching and learning

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Authors: Zorica Tomičić, Ružica Tomičić, Peter Raspor

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Growing resistance of pathogenic yeast Candida glabrata to many classes of antifungal drugs has stimulated efforts to discover new agents to combat a rising number of invasive C. glabrata infections, which deserves a great deal of concern due to the high mortality rate in immunocompromised populations. One promising strategy is the use of probiotic microorganisms, which, when administered in adequate amounts, confers a health benefit. A selected number of probiotic organisms, Saccharomyces boulardii among them, have been tested as potential biotherapeutic agents. The aim of this study was to investigate the effect of the probiotic yeast S. boulardii on the adhesion of clinical isolates of C. glabrata at different temperatures, pH values, and in the presence of three clinically important antifungal drugs, such as fluconazole, itraconazole and amphotericin B. The method used to assess adhesion was crystal violet staining. The selection of antimycotics concentrations used in the adhesion assay was based on minimum inhibitory concentrations (MICs) obtained by the preliminarily performed microdilution modification of the Reference method for broth dilution antifungal susceptibility testing of yeast (Clinical and Laboratory Standards Institute (CLSI), standard M27-A2). the results showed that despite the nonadhesiveness of S. boulardii cells, probiotic yeast significantly suppressed the adhesion of C. glabrata strains. Besides, at specific strain ratios, a slight stimulatory effect was observed in some C. glabrata strains, which highlights the importance of strain specificity and opens up further research interests. When environmental conditions are considered, temperature and pH significantly influenced co-culture adhesion of C. glabrata and S. boulardii. The adhesion of C. glabrata strains was relatively equally reduced over all tested temperature range (28°C, 37°C, 39°C and 42°C) in the presence of S. boulardii cells, while the adhesion of a few C. glabrata strains were significantly stimulated at 28°C and suppressed at 42°C. Further, the adhesion was highly dependent on pH, with the highest adherence at pH 4 and lowest at pH 8.5. It was observed that S. boulardii did not manage to suppress the adhesion of C. glabrata strains at high pH. Antimycotics on the other hand showed a greater impact, since S. boulardii failed to affect co-culture adhesion at higher antimycotics concentrations. As expected, exposure to various concentrations of amphotericin B significantly reduced the adherence ability of C.glabrata strains both in a single culture and co-culture with S. boulardii. Therefore, it can be speculated that S. boulardii could substitute the effect of antimycotics in a range concentrations and with specific type of strains. This would certainly change the view on the treatment of yeast infections in the future.

Keywords: adhesion, antimycotics, candida glabrata, saccharomyces boulardii

Procedia PDF Downloads 45

Authors: Ojochenemi J. Onubi, Debbi Marais, Lorna Aucott, Friday Okonofua, Amudha Poobalan

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Background: Obesity is a worldwide epidemic with major health and economic consequences. Pregnancy is a trigger point for the development of obesity, and maternal obesity is associated with significant adverse effects in the mother and child. Nigeria is experiencing a double burden of under- and over-nutrition with rising levels of obesity particularly in women. However, there is scarcity of data on maternal obesity in Nigeria and other African countries. Aims and Objectives: This project aimed at identifying crucial components of potential interventions for maternal obesity in Nigeria. The objectives were to assess the prevalence, effects, and distribution of maternal obesity; knowledge, attitude and practice (KAP) of pregnant women and maternal healthcare providers; and identify existing interventions for maternal obesity in Nigeria. Methodology: A systematic review and meta-analysis were initially conducted to appraise the existing literature on maternal obesity in Africa. Following this, a quantitative questionnaire survey of the KAP of pregnant women and a qualitative interview study of the KAP of Health Care Workers (HCW) were conducted in seven secondary and tertiary hospitals across Nigeria. Quantitative data was analysed using SPSS statistical software, while thematic analysis was conducted for qualitative data. Results: Twenty-nine studies included in the systematic review showed significant prevalence, socio-demographic associations, and adverse effects of maternal obesity on labour, maternal, and child outcomes in Africa. The questionnaire survey of 435 mothers revealed a maternal obesity prevalence of 17.9% among mothers who registered for antenatal care in the first trimester. The mothers received nutrition information from different sources and had insufficient knowledge of their own weight category or recommended Gestational Weight Gain (GWG), causes, complications, and safe ways to manage maternal obesity. However, majority of the mothers were of the opinion that excess GWG is avoided in pregnancy and some practiced weight management (diet and exercise) during pregnancy. For the qualitative study, four main themes were identified: ‘Concerns about obesity in pregnancy’, ‘Barriers to care for obese pregnant women’, ‘Practice of care for obese pregnant women’, and ‘Improving care for obese pregnant women’. HCW expressed concerns about rising levels of maternal obesity, lack of guidelines for the management of obese pregnant women and worries about unintended consequences of antenatal interventions. ‘Barriers’ included lack of contact with obese women before pregnancy, late registration for antenatal care, and perceived maternal barriers such as socio-cultural beliefs of mothers and poverty. ‘Practice’ included anticipatory care and screening for possible complications, general nutrition education during antenatal care and interdisciplinary care for mothers with complications. HCW offered suggestions on improving care for obese women including timing, type, and settings of interventions; and the need for involvement of other stake holders in caring for obese pregnant women. Conclusions: Culturally adaptable/sensitive interventions should be developed for the management of obese pregnant women in Africa. Education and training of mothers and health care workers, and provision of guidelines are some of the components of potential interventions in Nigeria.

Keywords: Africa, maternal, obesity, pregnancy

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Authors: Rohit Kamal, Devaki Perumal Rajaram, Rajam Krishna, Sai Kumar Pindagiri, Silas Danielraj

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Introduction: According to WHO, Global health observatory at least 2.8 million people die each year because of obesity and overweight. This is mainly because of the adverse metabolic effects of obesity and overweight on blood pressure, lipid profile especially cholesterol and insulin resistance. To achieve optimum health WHO has set the BMI in the range of 18.5 to 24.9 kg/m2. Due to modernization of life style, physical exercise in the form of work is no longer a possibility and hence an effective way to burn out calories to achieve the optimum BMI is the need of the hour. Studies have shown that exercising for more than 60 minutes /day helps to maintain the weight and to reduce the weight exercise should be done for 90 minutes a day. Moderate exercise for about 30 min is essential for burning up of calories. People with low endurance fail to perform even the low intensity exercise for minimal time. Hence, it is necessary to find out some effective method to increase the endurance time. Methodology: This study was approved by the Institutional Ethical committee of our college. After getting written informed consent, 25 apparently healthy males between the age group 18-20 years were selected. Subjects are with muscular disorder, subjects who are Hypertensive, Diabetes, Smokers, Alcoholics, taking drugs affecting the muscle strength. To determine the endurance time: Maximum voluntary contraction (MVC) was measured by asking the participants to squeeze the hand grip dynamometer as hard as possible and hold it for 3 seconds. This procedure was repeated thrice and the average of the three reading was taken as the maximum voluntary contraction. The participant was then asked to squeeze the dynamometer and hold it at 70% of the maximum voluntary contraction while hearing fast tempo music which was played for about ten minutes then the participant was asked to relax for ten minutes and was made to hold the hand grip dynamometer at 70% of the maximum voluntary contraction while hearing slow tempo music. To avoid the bias of getting habituated to the procedure the order of hearing for the fast and slow tempo music was changed. The time for which they can hold it at 70% of MVC was determined by using a stop watch and that was taken as the endurance time. Results: The mean value of the endurance time during fast and slow tempo music was compared in all the subjects. The mean MVC was 34.92 N. The mean endurance time was 21.8 (16.3) seconds with slow tempo music which was more then with fast tempo music with which the mean endurance time was 20.6 (11.7) seconds. The preference was more for slow tempo music then for fast tempo music. Conclusion: Music when played during exercise by some unknown mechanism helps to increase the endurance time by alleviating the symptoms of lactic acid accumulation.

Keywords: endurance time, fast tempo music, maximum voluntary contraction, slow tempo music

Procedia PDF Downloads 279

Authors: Ioannis Souris

Abstract:

In this paper, we would like to present how we taught German through playwriting and analyze the usefulness of this method for teaching languages and cultivating a sense of political agency in students and teachers alike. Last academic year, we worked at the German Saturday School in Greenwich, London. This school offers Saturday German lessons to children whose parents are German, living in London. The lessons are two hours long, and the children’s level of German varies according to how often or how much German is spoken at home or how often the families visit Germany (as well as other factors which will be discussed in more detail in the paper). The directors of the school provide teachers with learning material and course books, but they strongly encourage individual input on lesson structure and methods of teaching German. The class we taught consisted of six eight-to-nine-year-olds. Midway into the academic year, we ran out of teaching material, and we, therefore, decided to write a play. In the paper, we would like to explore the process we followed in creating or writing this play and how this encouraged the children to collaborate and exercise their skills in writing, storytelling, speaking, and opinion-sharing. We want to examine the impact this project had on the children who wrote and performed the play, the wider community of the Saturday school, and the development of our language teaching practice. We found, for instance, that some students, who were quiet or shy, became very open and outspoken in the process of writing and performing the play. They took the initiative and led the process, putting us, their teachers, in the role of simple observers or facilitators. When we showed the play in front of the school, the other children and teachers, as audience members, also became part of the process as they commented on the plot, language, and characters and gave feedback on further development. In the paper, we will discuss how this teaching project fits into recent developments in the research of creativity and the teaching of languages and how engagement with creative approaches to teaching has the potential to question and subvert traditional notions of ‘lesson’, ‘teacher’, and ‘student’. From the moment a questioning of norms takes place, we inadvertently raise questions about politics, agency, and resistance. We will conclude the paper with a definition of what we mean by ‘political agency’ within the context of our teaching project and education, in general, and why inspiring creativity and imagination within teaching can be considered a political act. Finally, our aim in this paper will be to propose the possibility of analyzing teaching languages through creativity and political agency theories.

Keywords: innovation in language teaching and learning, language acquisition and learning, language curriculum development, language education

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Authors: Sibashish Baksi, Ujjaini Sarkar, Sudeshna Saha

Abstract:

In the present study, hydrolysis of Pinus roxburghi wood powder was carried out with Viscozyme, and kinetics of the hydrolysis has been investigated. Finely ground sawdust is submerged into 2% aqueous peroxide solution (pH=11.5) and pretreated through autoclaving, probe sonication, and alkaline peroxide pretreatment. Afterward, the pretreated material is subjected to hydrolysis. A chain of experiments was executed with delignified biomass (50 g/l) and varying enzyme concentrations (24.2–60.5 g/l). In the present study, 14.32 g/l of glucose, along with 7.35 g/l of xylose, have been recovered with a viscozyme concentration of 48.8 g/l and the same condition was treated as optimum condition. Additionally, thermal deactivation of viscozyme has been investigated and found to be gradually decreasing with escalated enzyme loading from 48.4 g/l (dissociation constant= 0.05 h⁻¹) to 60.5 g/l (dissociation constant= 0.02 h⁻¹). The hydrolysis reaction is a pseudo first-order reaction, and therefore, the rate of the hydrolysis can be expressed as a fractal-like kinetic equation that communicates between the product concentration and hydrolytic time t. It is seen that the value of rate constant (K) increases from 0.008 to 0.017 with augmented enzyme concentration from 24.2 g/l to 60.5 g/l. Greater value of K is associated with stronger enzyme binding capacity of the substrate mass. However, escalated concentration of supplied enzyme ensures improved interaction with more substrate molecules resulting in an enhanced de-polymerization of the polymeric sugar chains per unit time which eventually modifies the physiochemical structure of biomass. All fractal dimensions are in between 0 and 1. Lower the value of fractal dimension, more easily the biomass get hydrolyzed. It can be seen that with increased enzyme concentration from 24.2 g/l to 48.4 g/l, the values of fractal dimension go down from 0.1 to 0.044. This indicates that the presence of more enzyme molecules can more easily hydrolyze the substrate. However, an increased value has been observed with a further increment of enzyme concentration to 60.5g/l because of diffusional limitation. It is evident that the hydrolysis reaction system is a heterogeneous organization, and the product formation rate depends strongly on the enzyme diffusion resistances caused by the rate-limiting structures of the substrate-enzyme complex. Value of the rate constant increases from 1.061 to 2.610 with escalated enzyme concentration from 24.2 to 48.4 g/l. As the rate constant is proportional to Fick’s diffusion coefficient, it can be assumed that with a higher concentration of enzyme, a larger amount of enzyme mass dM diffuses into the substrate through the surface dF per unit time dt. Therefore, a higher rate constant value is associated with a faster diffusion of enzyme into the substrate. Regression analysis of time curves with various enzyme concentrations shows that diffusion resistant constant increases from 0.3 to 0.51 for the first two enzyme concentrations and again decreases with enzyme concentration of 60.5 g/l. During diffusion in a differential scale, the enzyme also experiences a greater resistance during diffusion of larger dM through dF in dt.

Keywords: viscozyme, glucose, fractal kinetics, thermal deactivation

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Authors: Jianuo Sun, Jinghan Wang, Sirui Zhang, Chenhan Xu, Hongxia Hao, Hong Zhou

Abstract:

In recent years, the diversification and industrialization of drug-related crimes have posed significant threats to public health and safety globally. The widespread and increasingly younger demographics of drug users and the persistence of drug-impaired driving incidents underscore the urgency of this issue. Drug detection, a specialized forensic activity, is pivotal in identifying and analyzing substances involved in drug crimes. It relies on pharmacological and chemical knowledge and employs analytical chemistry and modern detection techniques. However, current drug detection methods are limited by their inability to perform semi-quantitative, real-time field analyses. They require extensive, complex laboratory-based preprocessing, expensive equipment, and specialized personnel and are hindered by long processing times. This study introduces an alternative approach using nucleic acid aptamers and Aggregation-Induced Emission (AIE) technology. Nucleic acid aptamers, selected artificially for their specific binding to target molecules and stable spatial structures, represent a new generation of biosensors following antibodies. Rapid advancements in AIE technology, particularly in tetraphenyl ethene-based luminous, offer simplicity in synthesis and versatility in modifications, making them ideal for fluorescence analysis. This work successfully synthesized, isolated, and purified an AIE molecule and constructed a probe comprising the AIE molecule, nucleic acid aptamers, and exonuclease for cocaine detection. The probe demonstrated significant relative fluorescence intensity changes and selectivity towards cocaine over other drugs. Using 4-Butoxytriethylammonium Bromide Tetraphenylethene (TPE-TTA) as the fluorescent probe, the aptamer as the recognition unit, and Exo I as an auxiliary, the system achieved rapid detection of cocaine within 5 mins in aqueous and urine, with detection limits of 1.0 and 5.0 µmol/L respectively. The probe-maintained stability and interference resistance in urine, enabling quantitative cocaine detection within a certain concentration range. This fluorescent sensor significantly reduces sample preprocessing time, offers a basis for rapid onsite cocaine detection, and promises potential for miniaturized testing setups.

Keywords: drug detection, aggregation-induced emission (AIE), nucleic acid aptamer, exonuclease, cocaine

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Authors: Ami Okabe, Daisuke Gondo, Akira Ogawa, Yasuhisa Hasegawa, Koichi Sato, Sadao Araki, Hideki Yamamoto

Abstract:

Membrane separation draws attention as the energy-saving technology. Pervaporation (PV) uses hydrophobic ceramic membranes to separate organic compounds from industrial wastewaters. PV makes it possible to separate organic compounds from azeotropic mixtures and from aqueous solutions. For the PV separation of low concentrations of organics from aqueous solutions, hydrophobic ceramic membranes are expected to have high separation performance compared with that of conventional hydrophilic membranes. Membrane separation performance is evaluated based on the pervaporation separation index (PSI), which depends on both the separation factor and the permeate flux. Ingenuity is required to increase the PSI such that the permeate flux increases without reducing the separation factor or to increase the separation factor without reducing the flux. A thin separation layer without defects and pinholes is required. In addition, it is known that the flux can be increased without reducing the separation factor by reducing the diffusion resistance of the membrane support. In a previous study, we prepared hydrophobic silica membranes by a molecular templating sol−gel method using cetyltrimethylammonium bromide (CTAB) to form pores suitable for permitting the passage of organic compounds through the membrane. We separated low-concentration organics from aqueous solutions by PV using these membranes. In the present study, hydrophobic silica membranes were prepared on a porous alumina hollow fiber support that is thinner than the previously used alumina support. Ethyl acetate (EA) is used in large industrial quantities, so it was selected as the organic substance to be separated. Hydrophobic silica membranes were prepared by dip-coating porous alumina supports with a -alumina interlayer into a silica sol containing CTAB and vinyltrimethoxysilane (VTMS) as the silica precursor. Membrane thickness increases with the lifting speed of the sol in the dip-coating process. Different thicknesses of the γ-alumina layer were prepared by dip-coating the support into a boehmite sol at different lifting speeds (0.5, 1, 3, and 5 mm s-1). Silica layers were subsequently formed by dip-coating using an immersion time of 60 s and lifting speed of 1 mm s-1. PV measurements of the EA (5 wt.%)/water system were carried out using VTMS hydrophobic silica membranes prepared on -alumina layers of different thicknesses. Water and EA flux showed substantially constant value despite of the change of the lifting speed to form the γ-alumina interlayer. All prepared hydrophobic silica membranes showed the higher PSI compared with the hydrophobic membranes using the previous alumina support of hollow fiber.

Keywords: membrane separation, pervaporation, hydrophobic, silica

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