Search results for: differential drive cmos rectifier

Authors: Wenxue Xu

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Fluid resistance damper is an important damping element to attenuate vehicle vibration. It converts vibration energy into thermal energy dissipation through oil throttling. It is a typical fluid-solid-heat coupling problem. A complete three-dimensional flow-structure-thermal coupling dynamics simulation model of a gas-filled fluid-resistance damper was established. The flow-condition-based interpolation (FCBI) method and direct coupling calculation method, the unit's FCBI-C fluid numerical analysis method and iterative coupling calculation method are used to achieve the damper dynamic response of the piston rod under sinusoidal excitation; the air chamber inflation pressure, spring compression characteristics, constant flow passage cross-sectional area and oil parameters, etc. The system parameters, excitation frequency, and amplitude and other excitation parameters are analyzed and compared in detail for the effects of differential pressure characteristics, velocity characteristics, flow characteristics and dynamic response of valve opening, floating piston response and piston rod output force characteristics. Experiments were carried out on some simulation analysis conditions. The results show that the node-based FCBI (flow-condition-based interpolation) fluid numerical analysis method and direct coupling calculation method can better guarantee the conservation of flow field calculation, and the calculation step is larger, but the memory is also larger; if the chamber inflation pressure is too low, the damper will become cavitation. The inflation pressure will cause the speed characteristic hysteresis to increase, and the sealing requirements are too strict. The spring compression characteristics have a great influence on the damping characteristics of the damper, and reasonable damping characteristic needs to properly design the spring compression characteristics; the larger the cross-sectional area of the constant flow channel, the smaller the maximum output force, but the more stable when the valve plate is opening.

Keywords: damper, fluid-structure-thermal coupling, heat generation, heat transfer

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Authors: Emma Castiglioni, Nigel Scrutton, Derren Heyes, Alistair Fielding

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By using light as trigger, it is possible to study many biological processes, such as the activity of genes, proteins, and other molecules, with precise spatiotemporal control. Caged compounds, where biologically active molecules are generated from an inert precursor upon laser photolysis, offer the potential to initiate such biological reactions with high temporal resolution. As light acts as the trigger for cleaving the protecting group, the ‘caging’ technique provides a number of advantages as it can be intracellular, rapid and controlled in a quantitative manner. We are developing caging strategies to study the catalytic cycle of a number of enzyme systems, such as nitric oxide synthase and ethanolamine ammonia lyase. These include the use of caged substrates, caged electrons and the possibility of caging the enzyme itself. In addition, we are developing a novel freeze-quench instrument to study these reactions, which combines rapid mixing and flashing capabilities. Reaction intermediates will be trapped at low temperatures and will be analysed by using electron paramagnetic resonance (EPR) spectroscopy to identify the involvement of any radical species during catalysis. EPR techniques typically require relatively long measurement times and very often, low temperatures to fully characterise these short-lived species. Therefore, common rapid mixing techniques, such as stopped-flow or quench-flow are not directly suitable. However, the combination of rapid freeze-quench (RFQ) followed by EPR analysis provides the ideal approach to kinetically trap and spectroscopically characterise these transient radical species. In a typical RFQ experiment, two reagent solutions are delivered to the mixer via two syringes driven by a pneumatic actuator or stepper motor. The new mixed solution is then sprayed into a cryogenic liquid or surface, and the frozen sample is then collected and packed into an EPR tube for analysis. The earliest RFQ instrument consisted of a hydraulic ram unit as a drive unit with direct spraying of the sample into a cryogenic liquid (nitrogen, isopentane or petroleum). Improvements to the RFQ technique have arisen from the design of new mixers in order to reduce both the volume and the mixing time. In addition, the cryogenic isopentane bath has been coupled to a filtering system or replaced by spraying the solution onto a surface that is frozen via thermal conductivity with a cryogenic liquid. In our work, we are developing a novel RFQ instrument which combines the freeze-quench technology with flashing capabilities to enable the studies of both thermally-activated and light-activated biological reactions. This instrument also uses a new rotating plate design based on magnetic couplings and removes the need for mechanical motorised rotation, which can otherwise be problematic at cryogenic temperatures.

Keywords: caged compounds, freeze-quench apparatus, photolysis, radicals

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Authors: H. Chabalala, A. Grootboom, M. Tang

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The innovative development, production, and clinical utilisation of African natural medicines requires frameworks from systematisation, innovation, registration. Afrika faces challenges when it comes to these sectors. The opposite is the case as is is evident in ancient Asian (Traditional Chinese Medicine and Indian Ayurveda and Siddha) medical systems, which are interfaced into their respective national health and educational systems. Afrikan Natural Medicines (ANMs) are yet to develop systematisation frameworks, i.e. disease characterisation and medicines classification. This paper explores classical medical systems drawn from Afrikan and Chinese experts in natural medicines. An Afrikological research methodology was used to conduct in-depth interviews with 20 key respondents selected through purposeful sampling technique. Data was summarised into systematisation frameworks for classical disease theories, patient categorisation, medicine classification, aetiology and pathogenesis of disease, diagnosis and prognosis techniques and treatment methods. It was discovered that ancient Afrika had systematic medical cosmologies, remnants of which are evident in most Afrikan cultural health practices. Parallels could be drawn from classical medical concepts of antiquity, like Chinese Taoist and Indian tantric health systems. Data revealed that both the ancient and contemporary ANM systems were based on living medical cosmologies. The study showed that African Natural Healing Systems have etiological systems, general pathogenesis knowledge, differential diagnostic techniques, comprehensive prognosis and holistic treatment regimes. Systematisation models were developed out of these frameworks, and this could be used for evaluation of clinical research, medical application including development of curriculum for high-education. It was envisaged that frameworks will pave way towards the development, production and commercialisation of ANMs. This was piloted in inclusive innovation, technology transfer and commercialisation of South African natural medicines, cosmeceuticals, nutraceuticals and health infusions. The central model presented here in will assist in curriculum development and establishment of Afrikan Medicines Hospitals and Pharmaceutical Industries.

Keywords: African Natural Medicines, Indigenous Knowledge Systems, Medical Cosmology, Clinical Application

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Authors: Olubukayo-Opeyemi Oyetayo, Oscar Mendez-Lucio, Andreas Bender, Hans Kiefer

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The thermal melting curve of a protein provides information on its conformational stability and could provide cues on its aggregation behavior. Naturally-occurring osmolytes have been shown to improve the thermal stability of most proteins in a concentration-dependent manner. They are therefore commonly employed as additives in therapeutic protein purification and formulation. A number of intertwined and seemingly conflicting mechanisms have been put forward to explain the observed stabilizing effects, the most prominent being the preferential exclusion mechanism. We attempted to probe and summarize molecular mechanisms for thermal stabilization of a monoclonal antibody (mAb) by developing quantitative structure-activity relationships using a rationally-selected library of 120 osmolyte-like compounds in the polyhydric alcohols, amino acids and methylamines classes. Thermal stabilization potencies were experimentally determined by thermal shift assays based on differential scanning fluorimetry. The cross-validated QSAR model was developed by partial least squares regression using descriptors generated from Molecular Operating Environment software. Careful evaluation of the results with the use of variable importance in projection parameter (VIP) and regression coefficients guided the selection of the most relevant descriptors influencing mAb thermal stability. For the mAb studied and at pH 7, the thermal stabilization effects of tested compounds correlated positively with their fractional polar surface area and inversely with their fractional hydrophobic surface area. We cannot claim that the observed trends are universal for osmolyte-protein interactions because of protein-specific effects, however this approach should guide the quick selection of (de)stabilizing compounds for a protein from a chemical library. Further work with a large variety of proteins and at different pH values would help the derivation of a solid explanation as to the nature of favorable osmolyte-protein interactions for improved thermal stability. This approach may be beneficial in the design of novel protein stabilizers with optimal property values, especially when the influence of solution conditions like the pH and buffer species and the protein properties are factored in.

Keywords: thermal stability, monoclonal antibodies, quantitative structure-activity relationships, osmolytes

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Authors: Ishani Maheshika

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The intermediary role performed by freight forwarders in exportation has become significant in fulfilling businesses’ supply chain needs in this dynamic world. Since the success of exporter’s business is at present, highly reliant on supply chain optimization, cost efficiency, profitability, consistent service and responsiveness, the decision of selecting the most beneficial freight forwarder has become crucial for exporters. Although there are similar foreign researches, prior researches covering Sri Lankan setting are not in existence. Moreover, results vary with time, nature of industry and business environment factors. Therefore, a study from the perspective of Sri Lankan exporters was identified as a requisite to be researched. In order to identify and prioritize key factors which have affected the exporter’s decision in selecting freight forwarders in Sri Lankan context, Sri Lankan export industry was stratified into 22 sectors based on commodity using stratified sampling technique. One exporter from each sector was then selected using judgmental sampling to have a sample of 22. Factors which were identified through a pilot survey, was organized under 6 main criteria. A questionnaire was basically developed as pairwise comparisons using 9-point semantic differential scale and comparisons were done within main criteria and subcriteria. After a pre-testing, interviews and e-mail questionnaire survey were conducted. Data were analyzed using Analytic Hierarchy Process to determine priority vectors of criteria. Customer service was found to be the most important main criterion for Sri Lankan exporters. It was followed by reliability and operational efficiency respectively. The criterion of the least importance is company background and reputation. Whereas small sized exporters pay more attention to rate, reliability is the major concern among medium and large scale exporters. Irrespective of seniority of the exporter, reliability is given the prominence. Responsiveness is the most important sub criterion among Sri Lankan exporters. Consistency of judgments with respect to main criteria was verified through consistency ratio, which was less than 10%. Being more competitive, freight forwarders should come up with customized marketing strategies based on each target group’s requirements and expectations in offering services to retain existing exporters and attract new exporters.

Keywords: analytic hierarchy process, freight forwarders, main criteria, Sri Lankan exporters, subcriteria

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Authors: Ahmed Bahieldin, Ahmed Atef, Jamal S. M. Sabir, Nour O. Gadalla, Sherif Edris, Ahmed M. Alzohairy, Nezar A. Radhwan, Mohammed N. Baeshen, Ahmed M. Ramadan, Hala F. Eissa, Sabah M. Hassan, Nabih A. Baeshen, Osama Abuzinadah, Magdy A. Al-Kordy, Fotouh M. El-Domyati, Robert K. Jansen

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Wild salt-tolerant barley (Hordeum spontaneum) is the ancestor of cultivated barley (Hordeum vulgare or H. vulgare). Although the cultivated barley genome is well studied, little is known about genome structure and function of its wild ancestor. In the present study, RNA-Seq analysis was performed on young leaves of wild barley treated with salt (500 mM NaCl) at four different time intervals. Transcriptome sequencing yielded 103 to 115 million reads for all replicates of each treatment, corresponding to over 10 billion nucleotides per sample. Of the total reads, between 74.8 and 80.3% could be mapped and 77.4 to 81.7% of the transcripts were found in the H. vulgare unigene database (unigene-mapped). The unmapped wild barley reads for all treatments and replicates were assembled de novo and the resulting contigs were used as a new reference genome. This resultedin94.3 to 95.3%oftheunmapped reads mapping to the new reference. The number of differentially expressed transcripts was 9277, 3861 of which were uni gene-mapped. The annotated unigene- and de novo-mapped transcripts (5100) were utilized to generate expression clusters across time of salt stress treatment. Two-dimensional hierarchical clustering classified differential expression profiles into nine expression clusters, four of which were selected for further analysis. Differentially expressed transcripts were assigned to the main functional categories. The most important groups were ‘response to external stimulus’ and ‘electron-carrier activity’. Highly expressed transcripts are involved in several biological processes, including electron transport and exchanger mechanisms, flavonoid biosynthesis, reactive oxygen species (ROS) scavenging, ethylene production, signaling network and protein refolding. The comparisons demonstrated that mRNA-Seq is an efficient method for the analysis of differentially expressed genes and biological processes under salt stress.

Keywords: electron transport, flavonoid biosynthesis, reactive oxygen species, rnaseq

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Authors: Disha Bhanot, Vinish Kathuria

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This study focusses on the issue of distress sale in horticulture sector in India, which faces unique challenges, given the perishable nature of horticulture crops, seasonal production and paucity of post-harvest produce management links. Distress sale, from a farmer’s perspective may be defined as urgent sale of normal or distressed goods, at deeply discounted prices (way below the cost of production) and it is usually characterized by unfavorable conditions for the seller (farmer). The small and marginal farmers, often involved in subsistence farming, stand to lose substantially if they receive lower prices than expected prices (typically framed in relation to cost of production). Distress sale maximizes price uncertainty of produce leading to substantial income loss; and with increase in input costs of farming, the high variability in harvest price severely affects profit margin of farmers, thereby affecting their survival. The objective of this study is to model the occurrence of distress sale by tomato cultivators in the Indian state of Maharashtra, against the background of differential access to set of factors such as - capital, irrigation facilities, warehousing, storage and processing facilities, and institutional arrangements for procurement etc. Data is being collected using primary survey of over 200 farmers in key tomato growing areas of Maharashtra, asking information on the above factors in addition to seeking information on cost of cultivation, selling price, time gap between harvesting and selling, role of middleman in selling, besides other socio-economic variables. Farmers selling their produce far below the cost of production would indicate an occurrence of distress sale. Occurrence of distress sale would then be modelled as a function of farm, household and institutional characteristics. Heckman-two-stage model would be applied to find the probability/likelihood of a famer falling into distress sale as well as to ascertain how the extent of distress sale varies in presence/absence of various factors. Findings of the study would recommend suitable interventions and promotion of strategies that would help farmers better manage price uncertainties, avoid distress sale and increase profit margins, having direct implications on poverty.

Keywords: distress sale, horticulture, income loss, India, price uncertainity

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Authors: Daniela E. Marin, Cornelia Braicu, Gina C. Pistol, Roxana Cojocneanu-Petric, Ioana Berindan Neagoe, Mihail A. Gras, Ionelia Taranu

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Aristolochic acid (AA) is a carcinogenic, mutagenic, and nephrotoxic compound commonly found in the Aristolochiaceae family of plants. AA is frequently associated with urothelial carcinoma of the upper urinary tract in human and animals and is considered as being responsible for Balkan Endemic Nephropathy. The pig provides a good animal model because the porcine urological system is very similar to that of humans, both in aspects of physiology and anatomy. MicroRNA (miRNA) are small non-coding RNAs that have an impact on a wide range of biological processes by regulating gene expression at post-transcriptional level. The objective of this study was to analyze the miRNA profiling in the kidneys of AA intoxicated swine. For this purpose, ten TOPIGS-40 crossbred weaned piglets, 4-week-old, male and females with an initial average body weight of 9.83 ± 0.5 kg were studied for 28 days. They were given ad libitum access to water and feed and randomly allotted to one of the following groups: control group (C) or aristolochic acid group (AA). They were fed a maize-soybean-meal-based diet contaminated or not with 0.25mgAA/kg. To profile miRNA in the kidneys of pigs, microarrays and bioinformatics approaches were applied to analyze the miRNA in the kidney of control and AA intoxicated pigs. After normalization, our results have shown that a total of 5 known miRNAs and 4 novel miRNAs had different profiling in the kidney of intoxicated animals versus control ones. Expression of miR-32-5p, miR-497-5p, miR-423-3p, miR-218-5p, miR-128-3p were up-regulated by 0.25mgAA/kg feed, while the expression of miR-9793-5p, miR-9835-3p, miR-9840-3p, miR-4334-5p was down-regulated. The microRNA profiling in kidney of intoxicated animals was associated with modified expression of target genes as: RICTOR, LASP1, SFRP2, DKK2, BMI1, RAF1, IGF1R, MAP2K1, WEE1, HDGF, BCL2, EIF4E etc, involved in cell division cycle, apoptosis, cell differentiation and cell migration, cell signaling, cancer etc. In conclusion, this study provides new data concerning the microRNA profiling in kidney after aristolochic acid intoxications with important implications for human and animal health.

Keywords: aristolochic acid, kidney, microRNA, swine

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Authors: Hadi S. Hosseini, Larry A. Taber

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In the embryo, heart is initially a simple tubular structure that undergoes complex morphological changes as it transforms into a four-chambered pump. This work focuses on mechanisms that create heart tube (HT). The early embryo is composed of three relatively flat primary germ layers called endoderm, mesoderm, and ectoderm. Precardiac cells located within bilateral regions of the mesoderm called heart fields (HFs) fold and fuse along the embryonic midline to create the HT. The right and left halves of this plate fold symmetrically to bring their upper edges into contact along the midline, where they fuse. In a region near the fusion line, these layers then separate to generate the primitive HT and foregut, which then extend vertically. The anterior intestinal portal (AIP) is the opening at the caudal end of the foregut, which descends as the HT lengthens. The biomechanical mechanisms that drive this folding are poorly understood. Our central hypothesis is that folding is caused by differences in growth between the endoderm and mesoderm while subsequent extension is driven by contraction along the AIP. The feasibility of this hypothesis is examined using experiments with chick embryos and finite-element modeling (FEM). Fertilized white Leghorn chicken eggs were incubated for approximately 22-33 hours until appropriate Hamburger and Hamilton stage (HH5 to HH9) was reached. To inhibit contraction, embryos were cultured in media containing blebbistatin (myosin II inhibitor) for 18h. Three-dimensional models were created using ABAQUS (D. S. Simulia). The initial geometry consists of a flat plate including two layers representing the mesoderm and endoderm. Tissue was considered as a nonlinear elastic material with growth and contraction (negative growth) simulated using a theory, in which the total deformation gradient is given by F=F^*.G, where G is growth tensor and F* is the elastic deformation gradient tensor. In embryos exposed to blebbistatin, initial folding and AIP descension occurred normally. However, after HFs partially fused to create the upper part of the HT, fusion, and AIP descension stopped, and the HT failed to grow longer. These results suggest that cytoskeletal contraction is required only for the later stages of HT formation. In the model, a larger biaxial growth rate in the mesoderm compared to the endoderm causes the bilayered plate to bend ventrally, as the upper edge moves toward the midline, where it 'fuses' with the other half . This folding creates the upper section of the HT, as well as the foregut pocket bordered by the AIP. After this phase completes by stage HH7, contraction along the arch-shaped AIP pulls the lower edge of the plate downward, stretching the two layers. Results given by model are in reasonable agreement with experimental data for the shape of HT, as well as patterns of stress and strain. In conclusion, results of our study support our hypothesis for the creation of the heart tube.

Keywords: heart tube formation, FEM, chick embryo, biomechanics

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Authors: Susanne Manes, Anni Glaeser, Katharina Wick, Bernhard Strauss, Uwe Berger

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Introduction: Over the last decades growing rates of mental health concerns among children and adolescents have been observed. At the same time, physical well-being of children and adolescents becomes increasingly impaired as well. Schools play an important role in preventing mental and physical disorders and in promoting well-being. Self-esteem, as well as social integration, are vital influence factors for mental and physical well-being. The purpose of this study was to develop and evaluate the program 'VorteilJena' for secondary schools in Germany focusing on self-esteem and social integration to improve mental and physical well-being. Method: The school-based health promotion program was designed for students in 5th grade and higher. It consists of several short pedagogical exercises instructed by a teacher and were integrated into the regular class over the course of ten weeks. The exercises focused on fostering social integration using either tasks improving team spirit or exercises that increase tolerance and sense of belonging. Other exercises focused on strengthening the self-esteem of the students. Additionally, the program included a poster exhibition titled 'Belonging' which was put up in the school buildings. The exhibition comprised ten posters which addressed relevant risk factors and resources related to social integration and self-esteem. The study was a randomized controlled sequential study with a pre and post measurement conducted in ten German schools. A total of 1642 students (44% male) were recruited. Their age ranged from 9 to 21 years (M=12.93 years; SD= 2.11). The program was conducted in classes ranging from 5th to 12th grade. Results: The program improved wellbeing, self-esteem and social integration of the involved students compared to the control group. Differential effects depending on implementation rates or age of the students will be analyzed. Moreover, implications for future school-based health promotion programs targeting self-esteem and social integration will be discussed. Conclusion: Social integration considerably influences self-esteem and well-being of students and can be targeted by school-based programs including short and modest exercises. Since a sufficient implementation of health promotion programs is essential, the present program due to its practicability represents a good opportunity to install health promotion focusing on social integration in schools.

Keywords: social integration, well-being, health promotion in schools, self-esteem

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

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

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

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Authors: Maryam Firouzmandi, Moosa Miri

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

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

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Authors: Suphitcha Charoen-Amornkitt, Chokeanand Bussracumpakorn

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The tendency of the Karen backstrap weaving succession has gradually decreased due to the difficulty of weaving techniques and the relocation of the young generation. The Yang Nam Klat Nuea community, Nong Ya Plong District, Phetchaburi, is a Pwo Karen community that is seriously confronted with a lack of cultural heritage. Thus, a group of weavers was formed to revive the knowledge of weaving. However, they have been gradually confronted with culture assimilation to mainstream culture from the desire for marketing acceptance and imperative and forced the extinction of culture due to the disappearance of weaving details and techniques. Although there are practical solutions, i.e., product development, community improvement, knowledge improvement, and knowledge transfer, to inherit the Karen weaving culture, people in the community cannot fulfill their deep intention about the weaving inheritance as most solutions have focused on developing the commercial products and making the income instead of inheriting their knowledge. This research employed qualitative user research with an in-depth user interview to study communal knowledge transfer succession based on the internal involved parties, i.e., four expert weavers, three young weavers, and three 4th generation villagers. The purpose is to explore the correlation and mindset of villagers towards the culture with specific issues, including the psychology of culture, core knowledge and learning methods, cultural inheritance, and cultural engagement. As a result, the existing models of knowledge management mostly focused on tangible strategies, which can notice progress in short terms, such as direct teaching and consistent practicing. At the same time, the motivation and passion of inheritors were abolished while the research found that the young generation who profoundly connected with the textile culture will have a more significant intention to continue the culture. Therefore, this research suggests both internal and external solutions to treat the community. Regarding the internal solutions, family, weaving group, and school have an important role to participate with young villagers by encouraging activities to support the cultivating of Karen’s history, understanding their identities, and adapting the culture as a part of daily life. At the same time, collecting all of the knowledge in the archives, e.g., recorded video, instruction, and books, can crucially prevent the culture from extinction. Regarding the external solutions, this study suggests that working with social media will enhance the intimacy of textile culture, while the community should relieve the roles in marketing competition and start to drive cultural experiences to create a new market position. In conclusion, this research intends to explore the causes and motivation to support the transfer of the culture to the 4th generation villagers and to raise awareness of the diversity of culture in society. With these suggestions and the desire to improve pride and confidence in culture, the community agrees that strengthening the relationships between the young villagers and the weaving culture can bring attention and interest back to the weaving culture.

Keywords: Pwo Karen textile culture, backstrap weaving succession, cultural inheritance, knowledge transfer, knowledge management

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Authors: E. H. Szeto, E. Ammendola, J. V. Tabares, A. Starkey, J. Hay, J. G. McClung, C. J. Bryan

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Introduction: Suicide is a leading cause of death globally, which accounts for more deaths annually than war, acquired immunodeficiency syndrome, homicides, and car accidents, while an estimated 140 million individuals have significant suicide ideation (SI) each year in the United States. Typical risk factors such as hopelessness, depression, and psychiatric disorders can predict suicide ideation but cannot distinguish between those who ideate from those who attempt suicide (SA). The Fluid Vulnerability Theory of suicide posits that a person’s activation of the suicidal mode is predicated on one’s predisposition, triggers, baseline/acute risk, and protective factors. The current study compares self-conscious cognitive-affective states (including guilt, shame, anger towards the self, and suicidal beliefs) among patients based on the endorsement of recent SI (i.e., past two weeks; acute risk) and lifetime SA (i.e., baseline risk). Method: A total of 2,722 individuals in an outpatient primary care setting were included in this cross-sectional, observational study; data for 2,584 were valid and retained for analysis. The Differential Emotions Scale measuring guilt, shame, and self-anger and the Suicide Cognitions Scale measuring suicide cognitions were administered. Results: A total of 2,222 individuals reported no recent SI or lifetime SA (Group 1), 161 reported recent SI only (Group 2), 145 reported lifetime SA only (Group 3), 56 reported both recent SI and lifetime SA (Group 4). The Kruskal-Wallis test showed that guilt, shame, self-anger, and suicide cognitions were the highest for Group 4 (both recent SI and lifetime SA), followed by Group 2 (recent SI-only), then Group 3 (lifetime SA-only), and lastly, Group 1 (no recent SI or lifetime SA). Conclusion: The results on recent SI-only versus lifetime SA-only contribute to the literature on the Fluid Vulnerability Theory of suicide by capturing SI and SA in two different time periods, which signify the acute risks and chronic baseline risks of the suicidal mode, respectively. It is also shown that: (a) people with a lifetime SA reported more severe symptoms than those without, (b) people with recent SI reported more severe symptoms than those without, and (c) people with both recent SI and lifetime SA were the most severely distressed. Future studies may replicate the findings here with other pertinent risk factors such as thwarted belongingness, perceived burdensomeness, and acquired capability, the last of which is consistently linked to attempting among ideators.

Keywords: suicide, guilt, shame, self-anger, suicide cognitions, suicide ideation, suicide attempt

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Authors: Ahmed. Abdel Bary, Omneya. Khowessah, Mojahed. al-jamrah

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Introduction: The major challenge with the design of oral dosage forms lies with their poor bioavailability. The most frequent causes of low oral bioavailability are attributed to poor solubility and low permeability. The aim of this study was to develop solid nanodispersed tablet formulation of Glimepiride for the enhancement of the solubility and bioavailability. Methodology: Solid nanodispersions of Glimepiride (GMP) were prepared using two different ratios of 2 different carriers, namely; PEG6000, pluronic F127, and by adopting two different techniques, namely; solvent evaporation technique and fusion technique. A full factorial design of 2 3 was adopted to investigate the influence of formulation variables on the prepared nanodispersion properties. The best chosen formula of nanodispersed powder was formulated into tablets by direct compression. The Differential Scanning Calorimetry (DSC) analysis and Fourier Transform Infra-Red (FTIR) analysis were conducted for the thermal behavior and surface structure characterization, respectively. The zeta potential and particle size analysis of the prepared glimepiride nanodispersions was determined. The prepared solid nanodispersions and solid nanodispersed tablets of GMP were evaluated in terms of pre-compression and post-compression parameters, respectively. Results: The DSC and FTIR studies revealed that there was no interaction between GMP and all the excipients used. Based on the resulted values of different pre-compression parameters, the prepared solid nanodispersions powder blends showed poor to excellent flow properties. The resulted values of the other evaluated pre-compression parameters of the prepared solid nanodispersion were within the limits of pharmacopoeia. The drug content of the prepared nanodispersions ranged from 89.6 ± 0.3 % to 99.9± 0.5% with particle size ranged from 111.5 nm to 492.3 nm and the resulted zeta potential (ζ ) values of the prepared GMP-solid nanodispersion formulae (F1-F8) ranged from -8.28±3.62 mV to -78±11.4 mV. The in-vitro dissolution studies of the prepared solid nanodispersed tablets of GMP concluded that GMP- pluronic F127 combinations (F8), exhibited the best extent of drug release, compared to other formulations, and to the marketed product. One way ANOVA for the percent of drug released from the prepared GMP-nanodispersion formulae (F1- F8) after 20 and 60 minutes showed significant differences between the percent of drug released from different GMP-nanodispersed tablet formulae (F1- F8), (P<0.05). Conclusion: Preparation of glimepiride as nanodispersed particles proven to be a promising tool for enhancing the poor solubility of glimepiride.

Keywords: glimepiride, solid Nanodispersion, nanodispersed tablets, poorly water soluble drugs

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Authors: Seema Paul, Jesper Oppelstrup, Roger Thunvik, Vladimir Cvetkovic

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Lake Victoria is the second largest fresh water body in the world, located in East Africa with a catchment area of 250,000 km², of which 68,800 km² is the actual lake surface. The hydrodynamic processes of the shallow (40–80 m deep) water system are unique due to its location at the equator, which makes Coriolis effects weak. The paper describes a St.Venant shallow water model of Lake Victoria developed in COMSOL Multiphysics software, a general purpose finite element tool for solving partial differential equations. Depth soundings taken in smaller parts of the lake were combined with recent more extensive data to resolve the discrepancies of the lake shore coordinates. The topography model must have continuous gradients, and Delaunay triangulation with Gaussian smoothing was used to produce the lake depth model. The model shows large-scale flow patterns, passive tracer concentration and water level variations in response to river and tracer inflow, rain and evaporation, and wind stress. Actual data of precipitation, evaporation, in- and outflows were applied in a fifty-year simulation model. It should be noted that the water balance is dominated by rain and evaporation and model simulations are validated by Matlab and COMSOL. The model conserves water volume, the celerity gradients are very small, and the volume flow is very slow and irrotational except at river mouths. Numerical experiments show that the single outflow can be modelled by a simple linear control law responding only to mean water level, except for a few instances. Experiments with tracer input in rivers show very slow dispersion of the tracer, a result of the slow mean velocities, in turn, caused by the near-balance of rain with evaporation. The numerical and hydrodynamical model can evaluate the effects of wind stress which is exerted by the wind on the lake surface that will impact on lake water level. Also, model can evaluate the effects of the expected climate change, as manifest in changes to rainfall over the catchment area of Lake Victoria in the future.

Keywords: bathymetry, lake flow and steady state analysis, water level validation and concentration, wind stress

Procedia PDF Downloads 194

Authors: Amy Williamson, Kerry Armstrong, Jason Edwards, Patricia Obst

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Australian national policy endorses a responsive approach to work health and safety (WHS) regulation, combining positive motivators (education and guidance), with compliance monitoring and enforcement to encourage and secure compliance with legislation. Despite theoretical support for responsive regulation, there is limited evidence regarding how to achieve best results in practice. Using positive psychology as a novel paradigm, this study aims to investigate how non-punitive regulatory interactions can be improved to further encourage regulatory compliance in the construction industry. As part of a larger project, semi-structured interviews were conducted with 35 inspectorate staff and 11 managers in the Australian (Queensland) construction industry. Using an inductive, grounded approach, an in-depth qualitative investigation was conducted to identify the positive psychological principles which underpin effective use of the non-punitive aspects of responsive regulation. Results highlighted the importance of effective engagement between inspectors and industry managers. This involved the need to interact cooperatively and encourage compliance with WHS legislation. Several strategies were identified that assisted regulatory interactions and the ability of inspectors to engage. The importance of communication and interpersonal skills was reported to be critical to any interaction, regardless of the nature of the visit and regulatory tools used. In particular, the use of clear and open communication fostered trust and rapport which facilitated more positive interactions. The importance of respect and empathy was also highlighted. The need for provision of guidance and direction on how to achieve compliance was also reported. This related to ensuring companies understand their WHS obligations, providing specific advice regarding how to rectify a breach and meet compliance requirements, and ensuring sufficient follow up to confirm that compliance is successfully achieved. In the absence of imminent risk, allowing companies the opportunity to comply before further action is taken was also highlighted. Increased proactive engagement with industry to educate and promote the vision of safety at work was also reported. Finally, provision of praise and positive feedback was reported to assist interactions and encourage the continuation of good practices. Evidence from positive psychology and organisational psychology was obtained to support the use of each strategy in practice. In particular, the area of positive leadership provided a useful framework to consider the factors and conditions that drive positive interactions within the context of work health and safety and the specific relationship between inspectors and industry managers. This study provides fresh insight into key psychological principles which support non-punitive regulatory interactions in the area of workplace health and safety. The findings of this research contribute to a better understanding of how inspectors can enhance the efficacy of their regulatory interactions to improve compliance with legislation. Encouraging and assisting compliance through effective non-punitive activity offers a sustainable pathway for promoting safety and preventing fatalities and injuries in the construction industry.

Keywords: engagement, non-punitive approaches to compliance, positive interactions in the workplace, work health and safety compliance

Procedia PDF Downloads 125

Authors: Andrew Gray, Zhibing Zhang

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The ability for consumer products to deliver a sustained perfume response can be a key driver for a variety of applications. Many compounds in perfume oils are highly volatile, meaning they readily evaporate once the product is applied, and the longevity of the scent is poor. Perfume capsules have been introduced as a means of abating this evaporation once the product has been delivered. The impermeable capsules are aimed to be stable within the formulation, and remain intact during delivery to the desired substrate, only rupturing to release the core perfume oil through application of mechanical force applied by the consumer. This opens up the possibility of obtaining an olfactive response hours, weeks or even months after delivery, depending on the nature of the desired application. Tailoring the properties of the polymeric capsules to better address the needs of the application is not a trivial challenge and currently design of capsules is largely done by trial and error. The aim of this work is to have more predictive methods for capsule design depending on the consumer application. This means refining formulations such that they rupture at the right time for the specific consumer application, not too early, not too late. Finding the right balance between these extremes is essential if a benefit is sought with respect to neat addition of perfume to formulations. It is important to understand the forces that influence capsule rupture, first, by quantifying the magnitude of these different forces, and then by assessing bulk rupture in real-world applications to understand how capsules actually respond. Samples were provided by an industrial partner and the mechanical properties of individual capsules within the samples were characterized via a micromanipulation technique, developed by Professor Zhang at the University of Birmingham. The capsules were synthesized such as to change one particular physicochemical property at a time, such as core: wall material ratio, and the average size of capsules. Analysis of shell thickness via Transmission Electron Microscopy, size distribution via the use of a Mastersizer, as well as a variety of other techniques confirmed that only one particular physicochemical property was altered for each sample. The mechanical analysis was subsequently undertaken, showing the effect that changing certain capsule properties had on the response under compression. It was, however, important to link this fundamental mechanical response to capsule performance in real-world applications. As such, the capsule samples were introduced to a formulation and exposed to full scale stresses. GC-MS headspace analysis of the perfume oil released from broken capsules enabled quantification of what the relative strengths of capsules truly means for product performance. Correlations have been found between the mechanical strength of capsule samples and performance in terms of perfume release in consumer applications. Having a better understanding of the key parameters that drive performance benefits the design of future formulations by offering better guidelines on the parameters that can be adjusted without worrying about the performance effects, and singles out those parameters that are essential in finding the sweet spot for capsule performance.

Keywords: consumer products, mechanical and physicochemical properties, perfume capsules, rupture behaviour

Procedia PDF Downloads 112

Authors: S. J. Addinell, T. Richard, B. Evans

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The Deep Exploration Technologies Cooperative Research Centre (DET CRC) is researching and developing a new coiled tubing based greenfields mineral exploration drilling system utilising downhole water powered percussive drill tooling. This new drilling system is aimed at significantly reducing the costs associated with identifying mineral resource deposits beneath deep, barron cover. This system has shown superior rates of penetration in water-rich hard rock formations at depths exceeding 500 meters. Several key challenges exist regarding the deployment and use of these bottom hole assemblies for mineral exploration, and this paper discusses some of the key technical challenges. This paper presents experimental results obtained from the research program during laboratory and field testing of the prototype drilling system. A study of the morphological aspects of the cuttings generated during the percussive drilling process is presented and shows a strong power law relationship for particle size distributions. Several percussive drilling parameters such as RPM, applied fluid pressure and weight on bit have been shown to influence the particle size distributions of the cuttings generated. This has direct influence on other drilling parameters such as flow loop performance, cuttings dewatering, and solids control. Real-time, accurate knowledge of percussive system operating parameters will assist the driller in maximising the efficiency of the drilling process. The applied fluid flow, fluid pressure, and rock properties are known to influence the natural oscillating frequency of the percussive hammer, but this paper also shows that drill bit design, drill bit wear and the applied weight on bit can also influence the oscillation frequency. Due to the changing drilling conditions and therefore changing operating parameters, real-time understanding of the natural operating frequency is paramount to achieving system optimisation. Several techniques to understand the oscillating frequency have been investigated and presented. With a conventional top drive drilling rig, spectral analysis of applied fluid pressure, hydraulic feed force pressure, hold back pressure and drill string vibrations have shown the presence of the operating frequency of the bottom hole tooling. Unfortunately, however, with the implementation of a coiled tubing drilling rig, implementing a positive displacement downhole motor to provide drill bit rotation, these signals are not available for interrogation at the surface and therefore another method must be considered. The investigation and analysis of ground vibrations using geophone sensors, similar to seismic-while-drilling techniques have indicated the presence of the natural oscillating frequency of the percussive hammer. This method is shown to provide a robust technique for the determination of the downhole percussive oscillation frequency when used with a coiled tubing drill rig.

Keywords: cuttings characterization, drilling optimization, oscillation frequency, percussive drilling, spectral analysis

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Authors: Richard Mababu Mukiur

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Leadership is an important drive that plays a key role in the success and development of organizations, particularly in the current context of digital transformation, highly competitivity and globalization. Leaders are persons that hold a dominant and privileged position within an organization, field, or sector of activities and are able to manage, motivate and exercise a high degree of influence over other in order to achieve the institutional goals. They achieve commitment and engagement of others to embrace change, and to make good decisions. Leadership studies in higher education institutions have examined how effective leaders hold their organizations, and also to find approaches which fit best in the organizations context for its better management, transformation and improvement. Moreover, recent studies have highlighted the impact of leadership styles on organizational performance and innovation capacities, since some styles give better results than others. Effective leadership is part of learning process that take place through day-to-day tasks, responsibilities, and experiences that influence the organizational performance, innovation and engagement of employees. The adoption of appropriate leadership styles can improve organization results and encourage learning process, team skills and performance, and employees' motivation and engagement. In the case of case of Information Technology sector, leadership styles are particularly crucial since this sector is leading relevant changes and transformations in the knowledge society. In this context, the main objective of this study is to analyze managers leadership styles with their relation to organizational performance and innovation that may be mediated by learning organization process and demographic variables. Therefore, it was hypothesized that the transformational and transactional leadership will be the main style adopted in Information Technology sector and will influence organizational performance and innovation capacity. A sample of 540 participants from Information technology sector has been determined in order to achieve the objective of this study. The Multifactor Leadership Questionnaire was administered as the principal instrument, Scale of innovation and Learning Organization Questionnaire. Correlations and multiple regression analysis have been used as the main techniques of data analysis. The findings indicate that leadership styles have a relevant impact on organizational performance and innovation capacity. The transformational and transactional leadership are predominant styles in Information technology sector. The effective leadership style tend to be characterized by the capacity of generating and sharing knowledge that improve organization performance and innovation capacity. Managers are adopting and adapting their leadership styles that respond to the new organizational, social and cultural challenges and realities of contemporary society. Managers who encourage innovation, foster learning process, share experience are useful to the organization since they contribute to its development and transformation. Learning process capacity and demographic variables (age, gender, and job tenure) mediate the relationship between leadership styles, innovation capacity and organizational performance. The transformational and transactional leadership tend to enhance the organizational performance due to their significant impact on team-building, employees' engagement and satisfaction. Some practical implications and future lines of research have been proposed.

Keywords: leadership styles, tranformational leadership, organisational performance, organisational innovation

Procedia PDF Downloads 190

Authors: Ali Pourkazemi

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The transient radar method (TRM) is one of the non-destructive methods that was introduced by authors a few years ago. The transient radar method can be classified as a wave-based non destructive testing (NDT) method that can be used in a wide frequency range. Nevertheless, it requires a narrow band, ranging from a few GHz to a few THz, depending on the application. As a time-of-flight and real-time method, TRM can measure the electromagnetic properties of the sample under test not only quickly and accurately, but also blindly. This means that it requires no prior knowledge of the sample under test. For multi-layer structures, TRM is not only able to detect changes related to any parameter within the multi-layer structure but can also measure the electromagnetic properties of each layer and its thickness individually. Although the temperature, humidity, and general environmental conditions may affect the sample under test, they do not affect the accuracy of the Blind TRM algorithm. In this paper, the electromagnetic properties as well as the thickness of the individual building insulation materials - as a single-layer structure - are measured experimentally. Finally, the correlation between the reflection coefficients and some other technical parameters such as sound insulation, thermal resistance, thermal conductivity, compressive strength, and density is investigated. The sample to be studied is 30 cm x 50 cm and the thickness of the samples varies from a few millimeters to 6 centimeters. This experiment is performed with both biostatic and differential hardware at 10 GHz. Since it is a narrow-band system, high-speed computation for analysis, free-space application, and real-time sensor, it has a wide range of potential applications, e.g., in the construction industry, rubber industry, piping industry, wind energy industry, automotive industry, biotechnology, food industry, pharmaceuticals, etc. Detection of metallic, plastic pipes wires, etc. through or behind the walls are specific applications for the construction industry.

Keywords: transient radar method, blind electromagnetic geometrical parameter extraction technique, ultrafast nondestructive multilayer dielectric structure characterization, electronic measurement systems, illumination, data acquisition performance, submillimeter depth resolution, time-dependent reflected electromagnetic signal blind analysis method, EM signal blind analysis method, time domain reflectometer, microwave, milimeter wave frequencies

Procedia PDF Downloads 44

Authors: Wenya Shu, Ilinca Stanciulescu

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Carbon nanotubes (CNTs) possess attractive properties, such as high stiffness and strength, and high thermal and electrical conductivities, making them promising filler in multifunctional nanocomposites. Although CNTs can be efficient reinforcements, the expected level of mechanical performance of CNT-polymers is not often reached in practice due to the poor mechanical behavior of the CNT-polymer interfaces. It is believed that the interactions of CNT and polymer mainly result from the Van der Waals force. The interface debonding is a fracture and delamination phenomenon. Thus, the cohesive zone modeling (CZM) is deemed to give good capture of the interface behavior. The detailed, cohesive zone modeling provides an option to consider the CNT-matrix interactions, but brings difficulties in mesh generation and also leads to high computational costs. Homogenized models that smear the fibers in the ground matrix and treat the material as homogeneous are studied in many researches to simplify simulations. But based on the perfect interface assumption, the traditional homogenized model obtained by mixing rules severely overestimates the stiffness of the composite, even comparing with the result of the CZM with artificially very strong interface. A mechanical model that can take into account the interface debonding and achieve comparable accuracy to the CZM is thus essential. The present study first investigates the CNT-matrix interactions by employing cohesive zone modeling. Three different coupled CZM laws, i.e., bilinear, exponential and polynomial, are considered. These studies indicate that the shapes of the CZM constitutive laws chosen do not influence significantly the simulations of interface debonding. Assuming a bilinear traction-separation relationship, the debonding process of single CNT in the matrix is divided into three phases and described by differential equations. The analytical solutions corresponding to these phases are derived. A homogenized model is then developed by introducing a parameter characterizing interface sliding into the mixing theory. The proposed mechanical model is implemented in FEAP8.5 as a user material. The accuracy and limitations of the model are discussed through several numerical examples. The CZM simulations in this study reveal important factors in the modeling of CNT-matrix interactions. The analytical solutions and proposed homogenized model provide alternative methods to efficiently investigate the mechanical behaviors of CNT/polymer composites.

Keywords: carbon nanotube, cohesive zone modeling, homogenized model, interface debonding

Procedia PDF Downloads 102

Authors: Sandra Costa-Santos, Nadia Bertolino, Stephen Hicks, Vanessa May, Camilla Lewis

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This paper aims to elaborate the architectural theory on place-making that supported Claremont Court housing scheme (Edinburgh, United Kingdom). Claremont Court (1959-62) is a large post-war mixed development housing scheme designed by Basil Spence, which included ‘place-making’ as one of its founding principles. Although some stylistic readings of the housing scheme have been published, the theory on place-making that allegedly ruled the design has yet to be clarified. The architecture allows us to mark or make a place within space in order to dwell. Under the framework of contemporary philosophical theories of place, this paper aims to explore the relationship between place and dwelling through a cross-disciplinary reading of Claremont Court, with a view to develop an architectural theory on place-making. Since dwelling represents the way we are immersed in our world in an existential manner, this theme is not just relevant for architecture but also for philosophy and sociology. The research in this work is interpretive-historic in nature. It examines documentary evidence of the original architectural design, together with relevant literature in sociology, history, and architecture, through the lens of theories of place. First, the paper explores how the dwelling types originally included in Claremont Court supported ideas of dwelling or meanings of home. Then, it traces shared space and social ties in order to study the symbolic boundaries that allow the creation of a collective identity or sense of belonging. Finally, the relation between the housing scheme and the supporting theory is identified. The findings of this research reveal Scottish architect Basil Spence’s exploration of the meaning of home, as he changed his approach to the mass housing while acting as President of the Royal Incorporation of British Architects (1958-60). When the British Government was engaged in various ambitious building programmes, he sought to drive architecture to a wider socio-political debate as president of the RIBA, hence moving towards a more ambitious and innovative socio-architectural approach. Rather than trying to address the ‘genius loci’ with an architectural proposition, as has been stated, the research shows that the place-making theory behind the housing scheme was supported by notions of community-based on shared space and dispositions. The design of the housing scheme was steered by a desire to foster social relations and collective identities, rather than by the idea of keeping the spirit of the place. This research is part of a cross-disciplinary project funded by the Arts and Humanities Research Council. The findings present Claremont Court as a signifier of Basil Spence’s attempt to address the post-war political debate on housing in United Kingdom. They highlight the architect’s theoretical agenda and challenge current purely stylistic readings of Claremont Court as they fail to acknowledge its social relevance.

Keywords: architectural theory, dwelling, place-making, post-war housing

Procedia PDF Downloads 239

Authors: Amit Mallik, Anil K. Barik, Biswajit Pal

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The galloping advancement of research work on glass-ceramics stems from their wide applications in electronic industry and also to some extent in application oriented medical dentistry. TiO2, even in low concentration has been found to strongly influence the physical and mechanical properties of the glasses. Glass-ceramics is a polycrystalline ceramic material produced through controlled crystallization of glasses. Crystallization is accomplished by subjecting the suitable parent glasses to a regulated heat treatment involving the nucleation and growth of crystal phases in the glass. Mica glass-ceramics is a new kind of glass-ceramics based on the system SiO2•MgO•K2O•F. The predominant crystalline phase is synthetic fluormica, named fluorophlogopite. Mica containing glass-ceramics flaunt an exceptional feature of machinability apart from their unique thermal and chemical properties. Machinability arises from the randomly oriented mica crystals with a 'house of cards' microstructures allowing cracks to propagate readily along the mica plane but hindering crack propagation across the layers. In the present study, we have systematically investigated the crystallization, microstructure and mechanical behavior of barium fluorophlogopite mica-containing glass-ceramics of composition BaO•4MgO•Al2O3•6SiO2•2MgF2 nucleated by addition of 2, 4, 6 and 8 wt% TiO2. The glass samples were prepared by the melting technique. After annealing, different batches of glass samples for nucleation were fired at 730°C (2wt% TiO2), 720°C (4 wt% TiO2), 710°C (6 wt% TiO2) and 700°C (8 wt% TiO2) batches respectively for 2 h and ultimately heated to corresponding crystallization temperatures. The glass batches were analyzed by differential thermal analysis (DTA) and x-ray diffraction (XRD), scanning electron microscopy (SEM) and micro hardness indenter. From the DTA study, it is found that the fluorophlogopite mica crystallization exotherm appeared in the temperature range 886–903°C. Glass transition temperature (Tg) and crystallization peak temperature (Tp) increased with increasing TiO2 content up to 4 wt% beyond this weight% the glass transition temperature (Tg) and crystallization peak temperature (Tp) start to decrease with increasing TiO2 content up to 8 wt%. Scanning electron microscopy confirms the development of an interconnected ‘house of cards’ microstructure promoted by TiO2 as a nucleating agent. The increase in TiO2 content decreases the vicker’s hardness values in glass-ceramics.

Keywords: crystallization, fluormica glass, ‘house of cards’ microstructure, hardness

Procedia PDF Downloads 219

Authors: Shatakshi Garg

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As the world continues to grapple with the COVID-19 pandemic, India, one of the most populous democratic federal developing nation, continues to report the highest active cases and deaths, as well as struggle to let its health infrastructure not succumb to the exponentially growing requirements of hospital beds, ventilators, oxygen to save thousands of lives daily at risk. In this context, the paper outlines the handling of the COVID-19 pandemic since it first hit India in January 2020 – the policy decisions taken by the Union and the State governments from the larger perspective of its federal structure. The Constitution of India adopted in 1950 enshrined the federal relations between the Union and the State governments by way of the constitutional division of revenue-raising and expenditure responsibilities. By way of the 72nd and 73rd Amendments in the Constitution, powers and functions were devolved further to the third tier, namely the local governments, with the intention of further strengthening the federal structure of the country. However, with time, several constitutional amendments have shifted the scales in favour of the union government. The paper briefly traces some of these major amendments as well as some policy decisions which made the federal relations asymmetrical. As a result, data on key fiscal parameters helps establish how the union government gained upper hand at the expense of weak state governments, reducing the local governments to mere constitutional bodies without adequate funds and fiscal autonomy to carry out the assigned functions. This quasi-federal structure of India with the union government amassing the majority of power in terms of ‘funds, functions and functionaries’ exposed the perils of weakening sub-national governments post COVID-19 pandemic. With a complex quasi-federal structure and a heterogeneous population of over 1.3 billion, the announcement of a sudden nationwide lockdown by the union government was followed by a plight of migrants struggling to reach homes safely in the absence of adequate arrangements for travel and safety-net made by the union government. With limited autonomy enjoyed by the states, they were mostly dictated by the union government on most aspects of handling the pandemic, including protocols for lockdown, re-opening post lockdown, and vaccination drive. The paper suggests that certain policy decisions like demonetization, the introduction of GST, etc., taken by the incumbent government since 2014 when they first came to power, have further weakened the states and local governments, which have amounted to catastrophic losses, both economic and human. The role of the executive, legislature and judiciary are explored to establish how all these three arms of the government have worked simultaneously to further weaken and expose the fault-lines of the federal structure of India, which has lent the nation incapacitated to handle this pandemic. The paper then suggests the urgency of re-looking at the federal structure of the country and undertaking measures that strengthen the sub-national governments and restore the federal spirit as was enshrined in the constitution to avoid mammoth human and economic losses from a pandemic of this sort.

Keywords: COVID-19 pandemic, India, federal structure, economic losses

Procedia PDF Downloads 151

Authors: Ei Ei Hlaing, Narissara Lailerd, Sittiruk Roytrakul, Pichapat Piamrojanaphat

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Type 2 diabetes is one of the most common metabolic diseases all over the world. The pathogenesis of type 2 diabetes is not the only dysfunction of pancreatic beta cells but also insulin resistance in muscle, liver and adipose tissue. High levels of circulating free fatty acids, an increased lipid content of muscle cells, impaired insulin-mediated glucose uptake and diminished mitochondrial functioning are pathophysiological hallmarks of diabetic skeletal muscles. Purple rice (Oryza sativa L. indica) has been shown to have antidiabetic effects. However, the underlying mechanism(s) of antidiabetic activity of purple rice is still unraveled. In this research, to explore in-depth cellular mechanism(s), proteomic profile of purple rice supplemented type 2 diabetic rats’ skeletal muscle were analyzed contract with non-supplemented rats. Diabetic rats were induced high-fat diet combined with streptozotocin injection. By using one- dimensional gel electrophoresis (1-DE) and LC-MS/MS quantitative proteomic method, we analyzed proteomic profiles in skeletal muscle of normal rats, normal rats with purple rice supplementation, type 2 diabetic rats, and type 2 diabetic rats with purple rice supplementation. Total 2676 polypeptide expressions were identified. Among them, 24 peptides were only expressed in type 2 diabetic rats, and 24 peptides were unique peptides in type 2 diabetic rats with purple rice supplementation. Acetyl CoA carboxylase 1 (ACACA) found as unique protein in type 2 diabetic rats which is the major enzyme in lipid synthesis and metabolism. Interestingly, DNA damage response protein, heterogeneous nuclear ribonucleoprotein K [Mus musculus] (Hnrnpk), was upregulated in type 2 diabetic rats’ skeletal muscle. Meanwhile, unique proteins of type 2 diabetic rats with purple rice supplementation (bone morphogenetic 7 protein preproprotein, BMP7; and forkhead box protein NX4, Foxn4) involved with muscle cells growth through the regulation of TGF-β/Smad signaling network. Moreover, BMP7 may effect on insulin signaling through the downstream signaling of protein kinase B (Akt) which acts in protein synthesis, glucose uptake, and glycogen synthesis. In conclusion, our study supports that type 2 diabetes impairs muscular lipid metabolism. In addition, purple rice might recover the muscle cells growth and insulin signaling.

Keywords: proteomics, purple rice bran, skeletal muscle, type 2 diabetic rats

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Authors: Florent Cerdan, Anne-Gaëlle Denay, Annette Roy, Jean-Claude Grandidier, Éric Laine

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The insulation of MarkIII membrane of the Liquid Natural Gas Carriers (LNGC) consists of a load- bearing system made of panels in reinforced polyurethane foam (R-PUF). During the shipping, the cargo containment shall be potentially subject to risk events which can be water leakage through the wall ballast tank. The aim of these present works is to further develop understanding of water transfer mechanisms and water effect on properties of R-PUF. This multi-scale approach contributes to improve the durability. Macroscale / Mesoscale Firstly, the use of the gravimetric technique has allowed to define, at room temperature, the water transfer mechanisms and kinetic diffusion, in the R-PUF. The solubility follows a first kinetic fast growing connected to the water absorption by the micro-porosity, and then evolves linearly slowly, this second stage is connected to molecular diffusion and dissolution of water in the dense membranes polyurethane. Secondly, in the purpose of improving the understanding of the transfer mechanism, the study of the evolution of the buoyant force has been established. It allowed to identify the effect of the balance of total and partial pressure of mixture gas contained in pores surface. Mesoscale / Microscale The differential scanning calorimetry (DSC) and Dynamical Mechanical Analysis (DMA), have been used to investigate the hydration of the hard and soft segments of the polyurethane matrix. The purpose was to identify the sensitivity of these two phases. It been shown that the glass transition temperatures shifts towards the low temperatures when the solubility of the water increases. These observations permit to conclude to a plasticization of the polymer matrix. Microscale The Fourier Transform Infrared (FTIR) study has been used to investigate the characterization of functional groups on the edge, the center and mid-way of the sample according the duration of submersion. More water there is in the material, more the water fix themselves on the urethanes groups and more specifically on amide groups. The pic of C=O urethane shifts at lower frequencies quickly before 24 hours of submersion then grows slowly. The intensity of the pic decreases more flatly after that.

Keywords: porous materials, water sorption, glass transition temperature, DSC, DMA, FTIR, transfer mechanisms

Procedia PDF Downloads 489

Authors: Christine Y. Yeh, Brian D. Piening, Sarah M. Totten, Kimberly Kukurba, Wenyu Zhou, Kevin P. F. Contrepois, Gucci J. Gu, Sharon Pitteri, Michael Snyder

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Three million deaths worldwide are attributed to obesity. However, the biomolecular mechanisms that describe the link between adiposity and subsequent disease states are poorly understood. Insulin resistance characterizes approximately half of obese individuals and is a major cause of obesity-mediated diseases such as Type II diabetes, hypertension and other cardiovascular diseases. This study makes use of longitudinal quantitative and high-throughput multi-omics (genomics, epigenomics, transcriptomics, glycoproteomics etc.) methodologies on blood samples to develop multigenic and multi-analyte signatures associated with weight gain and insulin resistance. Participants of this study underwent a 30-day period of weight gain via excessive caloric intake followed by a 60-day period of restricted dieting and return to baseline weight. Blood samples were taken at three different time points per patient: baseline, peak-weight and post weight loss. Patients were characterized as either insulin resistant (IR) or insulin sensitive (IS) before having their samples processed via longitudinal multi-omic technologies. This comparative study revealed a wealth of biomolecular changes associated with weight gain after using methods in machine learning, clustering, network analysis etc. Pathways of interest included those involved in lipid remodeling, acute inflammatory response and glucose metabolism. Some of these biomolecules returned to baseline levels as the patient returned to normal weight whilst some remained elevated. IR patients exhibited key differences in inflammatory response regulation in comparison to IS patients at all time points. These signatures suggest differential metabolism and inflammatory pathways between IR and IS patients. Biomolecular differences associated with weight gain and insulin resistance were identified on various levels: in gene expression, epigenetic change, transcriptional regulation and glycosylation. This study was not only able to contribute to new biology that could be of use in preventing or predicting obesity-mediated diseases, but also matured novel biomedical informatics technologies to produce and process data on many comprehensive omics levels.

Keywords: insulin resistance, multi-omics, next generation sequencing, proteogenomics, type ii diabetes

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Authors: Vipin Kumar Verma, Neeta Sehgal, Om Prakash

Abstract:

Cyprinus carpio has a wide spread occurrence in the lakes and rivers of Europe and Asia. Heavy losses in natural environment due to anthropogenic activities, including pollution as well as pathogenic diseases have landed this fish in IUCN red list of vulnerable species. The significance of a suitable diet in preserving the health status of fish is widely recognized. In present study, artificial feed supplemented with leaves of two weed plants, Eichhornia crassipes and Ricinus communis were evaluated for their role on the fish immune system. To achieve this objective fish were acclimatized to laboratory conditions (25 ± 1 °C; 12 L: 12D) for 10 days prior to start of experiment and divided into 4 groups: non-challenged (negative control= A), challenged [positive control (B) and experimental (C & D)]. Group A, B were fed with non-supplemented feed while group C & D were fed with feed supplemented with 5% Eichhornia crassipes and 5% Ricinus communis respectively. Supplemented feeds were evaluated for their effect on growth, health, immune system and disease resistance in fish when challenged with Vibrio harveyi. Fingerlings of C. carpio (weight, 2.0±0.5 g) were exposed with fresh overnight culture of V. harveyi through bath immunization (concentration 2 Χ 105) for 2 hours on 10 days interval for 40 days. The growth was monitored through increase in their relative weight. The rate of mortality due to bacterial infection as well as due to effect of feed was recorded accordingly. Immune response of fish was analyzed through differential leucocyte count, percentage phagocytosis and phagocytic index. The effect of V. harveyi on fish organs were examined through histo-pathological examination of internal organs like spleen, liver and kidney. The change in the immune response was also observed through gene expression analysis. The antioxidant potential of plant extracts was measured through DPPH and FRAP assay and amount of total phenols and flavonoids were calculates through biochemical analysis. The chemical composition of plant’s methanol extracts was determined by GC-MS analysis, which showed presence of various secondary metabolites and other compounds. Investigation revealed immuno-modulatory effect of plants, when supplemented with the artificial feed of fish.

Keywords: immuno-modulation, gc-ms, Cyprinus carpio, Eichhornia crassipes, Ricinus communis

Procedia PDF Downloads 456

Authors: Jiri Cecrdle

Abstract:

This paper describes the concept of the W-WING whirl flutter aeroelastic demonstrator. Whirl flutter is the specific case of flutter that accounts for the additional dynamic and aerodynamic influences of the engine rotating parts. The instability is driven by motion-induced unsteady aerodynamic propeller forces and moments acting in the propeller plane. Whirl flutter instability is a serious problem that may cause the unstable vibration of a propeller mounting, leading to the failure of an engine installation or an entire wing. The complicated physical principle of whirl flutter required the experimental validation of the analytically gained results. W-WING aeroelastic demonstrator has been designed and developed at Czech Aerospace Research Centre (VZLU) Prague, Czechia. The demonstrator represents the wing and engine of the twin turboprop commuter aircraft. Contrary to the most of past demonstrators, it includes a powered motor and thrusting propeller. It allows the changes of the main structural parameters influencing the whirl flutter stability characteristics. Propeller blades are adjustable at standstill. The demonstrator is instrumented by strain gauges, accelerometers, revolution-counting impulse sensor, sensor of airflow velocity, and the thrust measurement unit. Measurement is supported by the in house program providing the data storage and real-time depiction in the time domain as well as pre-processing into the form of the power spectral densities. The engine is linked with a servo-drive unit, which enables maintaining of the propeller revolutions (constant or controlled rate ramp) and monitoring of immediate revolutions and power. Furthermore, the program manages the aerodynamic excitation of the demonstrator by the aileron flapping (constant, sweep, impulse). Finally, it provides the safety guard to prevent any structural failure of the demonstrator hardware. In addition, LMS TestLab system is used for the measurement of the structure response and for the data assessment by means of the FFT- and OMA-based methods. The demonstrator is intended for the experimental investigations in the VZLU 3m-diameter low-speed wind tunnel. The measurement variant of the model is defined by the structural parameters: pitch and yaw attachment stiffness, pitch and yaw hinge stations, balance weight station, propeller type (duralumin or steel blades), and finally, angle of attack of the propeller blade 75% section (). The excitation is provided either by the airflow turbulence or by means of the aerodynamic excitation by the aileron flapping using a frequency harmonic sweep. The experimental results are planned to be utilized for validation of analytical methods and software tools in the frame of development of the new complex multi-blade twin-rotor propulsion system for the new generation regional aircraft. Experimental campaigns will include measurements of aerodynamic derivatives and measurements of stability boundaries for various configurations of the demonstrator.

Keywords: aeroelasticity, flutter, whirl flutter, W WING demonstrator

Procedia PDF Downloads 56