Search results for: cross junction
3543 Investigation into the Homoepitaxy of AlGaN/GaN Heterostructure via Molecular Beam Epitaxy
Authors: Jiajia Yao, Guanlin Wu, Fang Liu, Junshuai Xue, Yue Hao
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As the production process of self-standing GaN substrates evolves, the commercialization of low dislocation density, large-scale, semi-insulating self-standing GaN substrates is gradually becoming a reality. This advancement has given rise to increased interest in GaN materials' homoepitaxial technology. However, at the homoepitaxial interface, there are considerable concentrations of impurity elements, including C, Si, and O, which generate parasitic leakage channels at the re-growth junction. This phenomenon results in leaked HEMTs that prove difficult to switch off, rendering them effectively non-functional. The emergence of leakage channels can also degrade the high-frequency properties and lower the power devices' breakdown voltage. In this study, the uniform epitaxy of AlGaN/GaN heterojunction with high electron mobility was accomplished through the surface treatment of the GaN substrates prior to growth and the design of the AlN isolation layer structure. By employing a procedure combining gallium atom in-situ cleaning and plasma nitridation, the C and O impurity concentrations at the homoepitaxial interface were diminished to the scale of 10¹⁷ cm-³. Additionally, the 1.5 nm nitrogen-rich AlN isolation layer successfully prevented the diffusion of Si impurities into the GaN channel layer. The result was an AlGaN/GaN heterojunction with an electron mobility of 1552 cm²/Vs and an electron density of 1.1 × 10¹³ cm-² at room temperature, obtained on a Fe-doped semi-insulating GaN substrate.Keywords: MBE, AlGaN/GaN, homogenerous epitaxy, HEMT
Procedia PDF Downloads 563542 Estrogen Controls Hepatitis C Virus Entry and Spread through the GPR30 Pathway
Authors: Laura Ulitzky, Dougbeh-Chris Nyan, Manuel M. Lafer, Erica Silberstein, Nicoleta Cehan, Deborah R. Taylor
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Hepatitis C virus (HCV)-associated hepatocellular carcinoma, fibrosis and cirrhosis are more frequent in men and postmenopausal women than in premenopausal women and women receiving hormone replacement therapy, suggesting that β-estradiol (estrogen) plays an innate role in preventing viral infection and liver disease. Estrogen classically acts through nuclear estrogen receptors or, alternatively, through the membrane-bound G-protein-coupled estrogen receptor (GPR30 or GPER). We observed a marked decrease in detectable virus when HCV-infected human hepatoma cells were treated with estrogen. The effect was mimicked by both Tamoxifen (Tam) and G1, a GPR30-specific agonist, and was reversed by the GPR30-specific antagonist, G15. Through GPR30, estrogen-mediated the down-regulation of occludin; a tight junction protein and HCV receptor, by promoting activation of matrix metalloproteinases (MMPs). Activated MMP-9 was secreted in response to estrogen, cleaving occludin in the extracellular Domain D, the motif required for HCV entry and spread. This pathway gives new insight into a novel innate immune pathway and the disparate host-virus responses to HCV demonstrated by the two sexes. Moreover, these data suggest that hormone replacement therapy may have beneficial antiviral properties for HCV-infected postmenopausal women and show promise for new antiviral treatments for both men and women.Keywords: HCV, estrogen, occludin, MMPs
Procedia PDF Downloads 4323541 1,8-Naphthalimide Substituted 4,4-Difluoroboradiaza-S-Indacene Dyads: Synthesis, Structure, Properties and Live-Cell Imaging
Authors: Madhurima Poddar, Vinay Sharma, Shaikh M. Mobin, Rajneesh Misra
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Three 1,8-naphthalimide (NPI) substituted 4,4-difluoroboradiaza-s-indacene (BODIPY) dyads were synthesized via Pd-catalyzed Sonogashira cross-coupling reaction of ethynyl substituted NPI with the meso-, β- and α-halogenated BODIPYs, respectively. The photophysical and electrochemical data reveals considerable electronic communication between the BODIPY and NPI moieties. The electronic absorption spectrum reveals that the substitution of NPI at α position of BODIPY exhibit better electronic communication between the NPI and the BODIPY units. The electronic structures of all the dyads exhibit planar geometries which are in a good correlation with the structures obtained from single crystal X-ray diffraction. The crystal structures of the dyads exhibit interesting supramolecular interactions. The dyads show good cytocompatibility with the potential of multicolor live-cell imaging; making them excellent candidates for biological applications. The work provides an important strategy of screening the substitution pattern at different position of BODIPYs which will be useful for the design of BODIPY based organic molecules for various optoelectronic applications as well as bio-imaging.Keywords: bio-imaging studies, cross-coupling, cyclic voltammetry, density functional calculations, fluorescence spectra, single crystal XRD, UV/Vis spectroscopy
Procedia PDF Downloads 1423540 Aerodynamic Design of Three-Dimensional Bellmouth for Low-Speed Open-Circuit Wind Tunnel
Authors: Harshavardhan Reddy, Balaji Subramanian
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A systematic parametric study to find the optimum bellmouth profile by relating geometric and performance parameters to satisfy a set of specifications is reported. A careful aerodynamic design of bellmouth intake is critical to properly direct the flow with minimal losses and maximal flow uniformity into the honeycomb located inside the settling chamber of an indraft wind tunnel, thus improving the efficiency of the entire unit. Design charts for elliptically profiled bellmouths with two different contraction ratios (9 and 18) and three different test section speeds (25 m/s, 50 m/s, and 75 m/s) were presented. A significant performance improvement - especially in the Coefficient of discharge and in the flow angularity and boundary layer thickness at the honeycomb inlet - was observed when an entry corner radius (r/D = 0.08) was added to the bellmouth profile. The nonuniformity at the honeycomb inlet drops by about three times (~1% to 0.3%) when moving from square to regular octagonal cross-section. An octagonal cross-sectioned bellmouth intake with L/d = 0.55, D/d = 1.625, and r/D = 0.08 met all the four target performance specifications and is proposed as the best choice for a low-speed wind tunnel.Keywords: bellmouth intake, low-speed wind tunnel, coefficient of discharge, nonuniformity, flow angularity, boundary layer thickness, CFD, aerodynamics
Procedia PDF Downloads 1893539 A Crossover between Avant-Garde Fashion and Contemporary Art: A Case Study of Alexander McQueen
Authors: Chi-Ying Yu
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Fashion design is, in fact, an aesthetic inquiry of fabric, style and human body. In recent years, close cooperation between the artistic circles and the fashion world has even brought fashion into the arena of contemporary art. This study offers a case study on the avant-garde fashion designer Alexander McQueen, investigating how he and his brand translate fashion into contemporary art at various levels. Firstly, in terms of his designs themselves, McQueen demonstrates through fashions his declarations on political and gender issues, demonstrating his unique barbarian aesthetics and creating an enchanting sublimity. Secondly, McQueen extends his fashion aesthetics into a cross-disciplinary performing method, and raises catwalk shows to the level of complete artistic experience. Finally, and also most importantly, the brand has been producing fashion movies for its seasonal design series. By means of an abstract, non-narrative visual language, these films essentially transform people’s experience of clothing – from the senses to the pure visual. This is not simply a cross-media artistic practice, but much more fundamentally a discourse on contemporary perceptual experience. From the case of Alexander McQueen, it can be argued that avant-garde fashion has broken through the boundary between design and art, issuing its own art manifesto through the field of art or non-art.Keywords: Alexander McQueen, avant-garde fashion, contemporary art, fashion film
Procedia PDF Downloads 3233538 Nano-emulsion/Nano-suspension as Precursors for Oral Dissolvable Film to Enhance Bioavalabilty for Poor-water Solubility Drugs
Authors: Yuan Yang, Mickey Lam
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Oral dissolvable films have been considered as a unique alternative approach to conventional oral dosage forms. The films could be administrated via the gastrointestinal tract as conventional dosages or through sublingual/buccal mucosa membranes, which could enhance drug bioavailability by avoiding the first-pass effect and improving permeability due to high blood flow and lymphatic circulation. This work has described a state-of-art technic using nano-emulsion/nano-suspension as a precursor for the film to enhance the bioavailability of BCS class II drugs. The drug molecules are consequentially processed through the emulsification, gelation, and film-casting processes. The gelation process is critical to stabilizing the nano-emulsion for the film-casting as well as controlling the drug release process. Furthermore, the size of the nanoparticle on the film has a strong correlation with the size of the micelles in the precursor and the condition of the gelation process. It has been discovered that nanoparticle from 200 nm to 300 nm has shown the highest permeability for sublingual administration. In one example shown in work, the bioavailability of a low solubilize drug has been increased from 10% to 24% via sublingual administration of the film. The increasing of the bioavailability was thought to be associated with the enhancement of the diffusion process of the drug in the saliva layer above the mucosa membrane and the fact that the presents of the emulsifier help lose the rigid junction of the mucosa cells.Keywords: oral dissolvable film, nano-suspension, nano-emulsion, bioavailability
Procedia PDF Downloads 1703537 A Study on the Assessment of Prosthetic Infection after Total Knee Replacement Surgery
Authors: Chun-Lang Chang, Chun-Kai Liu
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In this study, the patients that have undergone total knee replacement surgery from the 2010 National Health Insurance database were adopted as the study participants. The important factors were screened and selected through literature collection and interviews with physicians. Through the Cross Entropy Method (CE), Genetic Algorithm Logistic Regression (GALR), and Particle Swarm Optimization (PSO), the weights of the factors were obtained. In addition, the weights of the respective algorithms, coupled with the Excel VBA were adopted to construct the Case Based Reasoning (CBR) system. The results through statistical tests show that the GALR and PSO produced no significant differences, and the accuracy of both models were above 97%. Moreover, the area under the curve of ROC for these two models also exceeded 0.87. This study shall serve as a reference for medical staff as an assistance for clinical assessment of infections in order to effectively enhance medical service quality and efficiency, avoid unnecessary medical waste, and substantially contribute to resource allocations in medical institutions.Keywords: Case Based Reasoning, Cross Entropy Method, Genetic Algorithm Logistic Regression, Particle Swarm Optimization, Total Knee Replacement Surgery
Procedia PDF Downloads 3203536 Stress and Personality as Predictors of Aggressive Behaviour among Nurses of Private Hospitals in Imo State, Nigeria
Authors: Ngozi N. Sydney-Agbor, Chioma N. Ihegboro
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Stress and personality as factors influencing nurses’ aggressive behaviour were investigated. The participants comprised of one hundred and fifty nurses selected through convenience sampling technique from four (4) private hospitals in Imo State, Nigeria; namely: Eastern Summit Specialist Clinics and Maternity, St. David Hospital, New Cross Hospital, and Christian Teaching Hospital. The nurses were all females with ages between 20–35 and a mean age of 25.10 years and a standard deviation of 4.15. The participants were administered with Job Related Tension Scale, Type A Behaviour Scale and Buss- Perry Aggressive Behaviour Scale. Two hypotheses were postulated and tested. Cross- sectional survey and Regression Analysis were adopted as design and statistics respectively. Results showed that as stress increased, nurses aggression also increased. Personality also predicted nurses aggressive behaviour with Type As’ exhibiting higher aggression than Type Bs’.The study recommended that hospital management board should improve the welfare of the nurses and their morale should be boosted by involving them in policy-making concerning their welfare and care of their patients, this will help minimise situations capable of increasing aggressive behaviour. There should also be sensitization on the negative impact of aggressive behaviour to patients especially amongst the personality Type A’s who are more susceptible to aggression.Keywords: aggressive behaviour, nurses, personality, stress
Procedia PDF Downloads 3343535 A Cross Culture Analysis of Medicinal Plants and Phytotherapies: Highly Effective for Gastropathic Disorders among Three Ethnic Communities of South West Pakistan
Authors: Sheikh Z. Ul Abidin, Raees Khan, Rainer W. Bussmann, Mushtaq Ahmad, Shayan Jamshed, Humera Jabeen, Ajmal Khan
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Gastropathic disorders are increasing rapidly and millions patients are reported every years across the world. Herbal medicines and traditional phytotherapies are very effective for many diseases including gastropathic ailments. Many communities and study region have their own unique remedies for such diseases. The current study was aimed to investigate and document high valued medicinal plants and folk remedies for different gastropathic disorders among the three ethnic groups of three regions in South West Pakistan. A total of 104 semi-structured interviews involving experts of traditional knowledge in 21 localities of the three regions (D.I. Khan, Zhob and Mianwali) were conducted. The interviews were especially focused on the documentation of folk herbal remedies. The collected data was analyzed using different quantitative methods. The highly effective plants from all localities were identified with the help of local interviewers and collected for proper taxonomic identification. A total of 56 medicinal plants and 33 effective recipes for 12 gastropathic diseases were documented from all the three ethnic groups in 21 localities. Fabaceae and Asteraceae were most prominently used for different gastropathic diseases. Diarrhea, vomiting and dysentery were the most commonly diseases treated with herbal remedies. It was observed that the three communities shared knowledge about the use of medicinal plants, 35 species were commonly reported from all three areas. However, each community had also their own unique uses of medicinal plants, e.g. 23 plants species were only used in Zhob, 20 plant species were only reported in D.I. Khan and 16 species in Mianwali. The present study reveals that different communities and ethnic groups share some traditional knowledge and also have their own unique knowledge of plants utilization. Gastropathic disorder is increasing very rapidly and the traditional cross-cultural knowledge of medicinal plants use can be very effective for its cure.Keywords: cross cultural, ethnic groups, gastropathy, phytotherapies, South West Pakistan
Procedia PDF Downloads 2893534 Robustness Conditions for the Establishment of Stationary Patterns of Drosophila Segmentation Gene Expression
Authors: Ekaterina M. Myasnikova, Andrey A. Makashov, Alexander V. Spirov
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First manifestation of a segmentation pattern in the early Drosophila development is the formation of expression domains (along with the main embryo axis) of genes belonging to the trunk gene class. Highly variable expression of genes from gap family in early Drosophila embryo is strongly reduced by the start of gastrulation due to the gene cross-regulation. The dynamics of gene expression is described by a gene circuit model for a system of four gap genes. It is shown that for the formation of a steep and stationary border by the model it is necessary that there existed a nucleus (modeling point) in which the gene expression level is constant in time and hence is described by a stationary equation. All the rest genes expressed in this nucleus are in a dynamic equilibrium. The mechanism of border formation associated with the existence of a stationary nucleus is also confirmed by the experiment. An important advantage of this approach is that properties of the system in a stationary nucleus are described by algebraic equations and can be easily handled analytically. Thus we explicitly characterize the cross-regulation properties necessary for the robustness and formulate the conditions providing this effect through the properties of the initial input data. It is shown that our formally derived conditions are satisfied for the previously published model solutions.Keywords: drosophila, gap genes, reaction-diffusion model, robustness
Procedia PDF Downloads 3603533 The Antecedent Variables of Government Financial Accounting System (SAKD) Implementation and Its Consequences: Empirical Study on the Device of Regional Coordinating Agency for Development of Cross County, City Region III Central Java Province, Indo
Authors: Dona Primasari
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This study examines the antecedent variables of Government Financial Acccounting System (SAKD) implementation and its consequence. The antecedent variables are: decentralization of decision making, adaptation, and the manager support. The consequences are satisfaction and performance officer. This research represents the empirical test which used convenience sampling technics in data collection. The data were collected from 167 officers of local government in the Regional Coordinating Agency for Development of Cross County/City Region III Central Java Province. Data analysis used Structural Equation Model (SEM) with the AMOS 18.0 program. The result of hypothesis examination indicates that six raised hypothesis are accepted and two hypothesis are rejected.Keywords: decentralization of decision making, adaptation officer, manager support, implementation of Government Accounting Financial System (SAKD), satisfaction and performance officer
Procedia PDF Downloads 3853532 On the Effects of External Cross-Flow Excitation Forces on the Vortex-Induced-Vibrations of an Oscillating Cylinder
Authors: Abouzar Kaboudian, Ravi Chaithanya Mysa, Boo Cheong Khoo, Rajeev Kumar Jaiman
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Vortex induced vibrations can significantly affect the effectiveness of structures in aerospace as well as offshore marine industries. The oscillatory nature of the forces resulting from the vortex shedding around bluff bodies can result in undesirable effects such as increased loading, stresses, deflections, vibrations and noise in the structures, and also reduced fatigue life of the structures. To date, most studies concentrate on either the free oscillations or the prescribed motion of the bluff bodies. However, the structures in operation are usually subject to the external oscillatory forces (e.g. due to the platform motions in offshore industries). In this work, we present the effects of the external cross-flow forces on the vortex-induced vibrations of an oscillating cylinder. The effects of the amplitude, as well as the frequency of the external force on the fluid-forces on the oscillating cylinder are carefully studied and presented. Moreover, we present the transition of the response to be dominated by the vortex-induced-vibrations to the range where it is mostly dictated by the external oscillatory forces. Furthermore, we will discuss how the external forces can affect the flow structures around a cylinder. All results are compared against free oscillations of the cylinder.Keywords: circular cylinder, external force, vortex-shedding, VIV
Procedia PDF Downloads 3663531 Removal of Pb(II) Ions from Wastewater Using Magnetic Chitosan–Ethylene Glycol Diglycidyl Ether Beads as Adsorbent
Authors: Pyar Singh Jassal, Priti Rani, Rajni Johar
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The adsorption of Pb(II) ions from wastewater using ethylene glycol diglycidyl ether cross-linked magnetic chitosan beads (EGDE-MCB) was carried out by considering a number of parameters. The removal efficiency of the metal ion by magnetic chitosan beads (MCB) and its cross-linked derivatives depended on viz contact time, dose of the adsorbent, pH, temperature, etc. The concentration of Cd( II) at different time intervals was estimated by differential pulse anodic stripping voltammetry (DPSAV) using 797 voltametric analyzer computrace. The adsorption data could be well interpreted by Langmuir and Freundlich adsorption model. The equilibrium parameter, RL values, support that the adsorption (03530 A New Approach for Preparation of Super Absorbent Polymers: In-Situ Surface Cross-Linking
Authors: Reyhan Özdoğan, Mithat Çelebi, Özgür Ceylan, Mehmet Arif Kaya
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Super absorbent polymers (SAPs) are defined as materials that can absorb huge amount of water or aqueous solution in comparison to their own mass and retain in their lightly cross-linked structure. SAPs were produced from water soluble monomers via polymerization subsequently controlled crosslinking. SAPs are generally used for water absorbing applications such as baby diapers, patient or elder pads and other hygienic product industries. Crosslinking density (CD) of SAP structure is an essential factor for water absortion capacity (WAC). Low internal CD leads to high WAC values and vice versa. However, SAPs have low CD and high swelling capacities and tend to disintegrate when pressure is applied upon them, so SAPs under load cannot absorb liquids effectively. In order to prevent this undesired situation and to obtain suitable SAP structures having high swelling capacity and ability to work under load, surface crosslinking can be the answer. In industry, these superabsorbent gels are mostly produced via solution polymerization and then they need to be dried, grinded, sized, post polymerized and finally surface croslinked (involves spraying of a crosslinking solution onto dried and grinded SAP particles, and then curing by heat). It can easily be seen that these steps are time consuming and should be handled carefully for the desired final product. If we could synthesize desired final SAPs using less processes it will help reducing time and production costs which are very important for any industries. In this study, synthesis of SAPs were achieved successfully by inverse suspension (Pickering type) polymerization and subsequently in-situ surface cross-linking via using proper surfactants in high boiling point solvents. Our one-pot synthesis of surface cross-linked SAPs invovles only one-step for preparation, thus it can be said that this technique exhibits more preferable characteristic for the industry in comparison to conventional methods due to its one-step easy process. Effects of different surface crosslinking agents onto properties of poly(acrylic acid-co-sodium acrylate) based SAPs are investigated. Surface crosslink degrees are evaluated by swelling under load (SUL) test. It was determined water absorption capacities of obtained SAPs decrease with the increasing surface crosslink density while their mechanic properties are improved.Keywords: inverse suspension polymerization, polyacrylic acid, super absorbent polymers (SAPs), surface crosslinking, sodium polyacrylate
Procedia PDF Downloads 3183529 Cost Analysis of Optimized Fast Network Mobility in IEEE 802.16e Networks
Authors: Seyyed Masoud Seyyedoshohadaei, Borhanuddin Mohd Ali
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To support group mobility, the NEMO Basic Support Protocol has been standardized as an extension of Mobile IP that enables an entire network to change its point of attachment to the Internet. Using NEMO in IEEE 802.16e (WiMax) networks causes latency in handover procedure and affects seamless communication of real-time applications. To decrease handover latency and service disruption time, an integrated scheme named Optimized Fast NEMO (OFNEMO) was introduced by authors of this paper. In OFNEMO a pre-establish multi tunnels concept, cross function optimization and cross layer design are used. In this paper, an analytical model is developed to evaluate total cost consisting of signaling and packet delivery costs of the OFNEMO compared with RFC3963. Results show that OFNEMO increases probability of predictive mode compared with RFC3963 due to smaller handover latency. Even though OFNEMO needs extra signalling to pre-establish multi tunnel, it has less total cost thanks to its optimized algorithm. OFNEMO can minimize handover latency for supporting real time application in moving networks.Keywords: fast mobile IPv6, handover latency, IEEE802.16e, network mobility
Procedia PDF Downloads 1893528 CAM Use and Its Association with Quality of Life in a Sample of Lebanese Breast Cancer Patients: A Cross Sectional Study
Authors: Farah Naja, Romy Abi Fadel, Yasmin Aridi, Aya Zarif, Dania Hariri, Mohammad Alameddine, Anas Mugharbel, Maya Khalil, Zeina Nahleh, Arafat Tfayli
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The objective of this study is to assess the prevalence and determinants of CAM use among breast cancer patients in Beirut, Lebanon. A secondary objective is to evaluate the association between CAM use and quality of life (QOL). A cross-sectional survey was conducted on 180 breast cancer patients recruited from two major referral centers in Beirut. In a face to face interview, participants completed a questionnaire comprised of three sections: socio-demographic and lifestyle characteristics, breast cancer condition, and CAM use. The assessment of QOL was carried using the FACT-B Arabic version. Prevalence of CAM use since diagnosis was 40%. CAM use was negatively associated with age, treatment at a philanthropic hospital and positively associated with having an advanced stage of disease. The most commonly used CAM was ‘Special food’ followed by ‘Herbal teas’. Only 4% of CAM users cited health care professionals as influencing their choice of CAM. One in four patients disclosed CAM use to their treating physician. There was no significant association between CAM use and QOL. The use of CAM therapies among breast cancer patients is prevalent in Lebanon. Efforts should be dedicated at educating physicians to discuss CAM use with their patients and advising patients to disclose of their use with their physicians.Keywords: breast cancer , complementary medicine, alternative medicine, lebanon , quality of life
Procedia PDF Downloads 5053527 Design Optimisation of a Novel Cross Vane Expander-Compressor Unit for Refrigeration System
Authors: Y. D. Lim, K. S. Yap, K. T. Ooi
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In recent years, environmental issue has been a hot topic in the world, especially the global warming effect caused by conventional non-environmentally friendly refrigerants has increased. Several studies of a more energy-efficient and environmentally friendly refrigeration system have been conducted in order to tackle the issue. In search of a better refrigeration system, CO2 refrigeration system has been proposed as a better option. However, the high throttling loss involved during the expansion process of the refrigeration cycle leads to a relatively low efficiency and thus the system is impractical. In order to improve the efficiency of the refrigeration system, it is suggested by replacing the conventional expansion valve in the refrigeration system with an expander. Based on this issue, a new type of expander-compressor combined unit, named Cross Vane Expander-Compressor (CVEC) was introduced to replace the compressor and the expansion valve of a conventional refrigeration system. A mathematical model was developed to calculate the performance of CVEC, and it was found that the machine is capable of saving the energy consumption of a refrigeration system by as much as 18%. Apart from energy saving, CVEC is also geometrically simpler and more compact. To further improve its efficiency, optimization study of the device is carried out. In this report, several design parameters of CVEC were chosen to be the variables of optimization study. This optimization study was done in a simulation program by using complex optimization method, which is a direct search, multi-variables and constrained optimization method. It was found that the main design parameters, which was shaft radius was reduced around 8% while the inner cylinder radius was remained unchanged at its lower limit after optimization. Furthermore, the port sizes were increased to their upper limit after optimization. The changes of these design parameters have resulted in reduction of around 12% in the total frictional loss and reduction of 4% in power consumption. Eventually, the optimization study has resulted in an improvement in the mechanical efficiency CVEC by 4% and improvement in COP by 6%.Keywords: complex optimization method, COP, cross vane expander-compressor, CVEC, design optimization, direct search, energy saving, improvement, mechanical efficiency, multi variables
Procedia PDF Downloads 3673526 Raising Antibodies against Epoxyscillirosidine, the Toxic Principle Contained in Moraea pallida Bak. in Rabbits
Authors: Hamza I. Isa, Gezina C. H. Ferreira, Jan E. Crafford, Christoffel J. Botha
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Moraea pallida Bak. (yellow tulip) poisoning is the most important plant-induced cardiac glycoside toxicosis in South Africa. Cardiac glycoside poisonings collectively account for about 33 and 10 % mortalities due to plants, in large and small stock respectively, in South Africa. The toxic principle is 1α, 2α-epoxyscillirosidine, a bufadienolide. The aim of the study was to investigate the potential to develop a vaccine against epoxyscillirosidine. Epoxyscillirosidine and the related bufadienolides proscillaridin and bufalin, which are commercially available, were conjugated to the carrier proteins [Hen ovalbumin (OVA), bovine serum albumin (BSA) and keyhole limpet haemocyanin (KLH)], rendering them immunogenic. Adult male New Zealand White rabbits were immunized. In Trials 1 and 2, rabbits (n=6) were, each assigned to two groups. Experimental animals (n=3; n=4) were vaccinated with epoxyscillirosidine-OVA conjugate, while the control (n=3; n=2) were vaccinated with OVA, using Freund’s complete and incomplete and Montanide adjuvants, for Trials 1 and 2, respectively. In Trial 3, rabbits (n=15), randomly allocated to 5 equal groups (I, II, III, IV and V), were vaccinated with proscillaridin-BSA, bufalin-BSA, epoxyscillirosidine-KLH, epoxyscillirosidine-BSA conjugates, and BSA respectively, using Montanide as adjuvant. Vaccination was on Days 0, 21 and 42. Additional vaccinations were done on Day 56 and 63 for Trial 1. Vaccination was by intradermal injection of 0.4 ml of the immunogen (4 mg/ml [Trial 1] and 8 mg/ml for Trials 2 and Trial 3, respectively). Blood was collected pre-vaccination and at 3 week intervals following each vaccination. Antibody response was determined using an indirect ELISA. There was poor immune response associated with the dose (0.4 mg per rabbit) and adjuvant used in Trial 1. Antibodies were synthesized against the conjugate administered in Trial 2. For Trail 3, antibodies against the immunogens were successfully raised in rabbits with epoxyscillirosidine-KLH inducing the highest immune response. The antibodies raised against proscillaridin and bufalin cross-reacted with epoxyscillirosidine when used as antigen in the ELISA. The study successfully demonstrated the synthesis of antibodies against the bufadienolide conjugates administered. The cross-reactivity of proscillaridin and bufalin with epoxyscillirosidine could potentially be utilized as alternative to epoxyscillirosidine in future studies to prevent yellow tulp poisoning by vaccination.Keywords: antibodies , bufadienolides, cross-reactivity, epoxyscillirosidine, Moraea pallida, poisoning
Procedia PDF Downloads 1483525 Numerical Investigation on Design Method of Timber Structures Exposed to Parametric Fire
Authors: Robert Pečenko, Karin Tomažič, Igor Planinc, Sabina Huč, Tomaž Hozjan
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Timber is favourable structural material due to high strength to weight ratio, recycling possibilities, and green credentials. Despite being flammable material, it has relatively high fire resistance. Everyday engineering practice around the word is based on an outdated design of timber structures considering standard fire exposure, while modern principles of performance-based design enable use of advanced non-standard fire curves. In Europe, standard for fire design of timber structures EN 1995-1-2 (Eurocode 5) gives two methods, reduced material properties method and reduced cross-section method. In the latter, fire resistance of structural elements depends on the effective cross-section that is a residual cross-section of uncharred timber reduced additionally by so called zero strength layer. In case of standard fire exposure, Eurocode 5 gives a fixed value of zero strength layer, i.e. 7 mm, while for non-standard parametric fires no additional comments or recommendations for zero strength layer are given. Thus designers often implement adopted 7 mm rule also for parametric fire exposure. Since the latest scientific evidence suggests that proposed value of zero strength layer can be on unsafe side for standard fire exposure, its use in the case of a parametric fire is also highly questionable and more numerical and experimental research in this field is needed. Therefore, the purpose of the presented study is to use advanced calculation methods to investigate the thickness of zero strength layer and parametric charring rates used in effective cross-section method in case of parametric fire. Parametric studies are carried out on a simple solid timber beam that is exposed to a larger number of parametric fire curves Zero strength layer and charring rates are determined based on the numerical simulations which are performed by the recently developed advanced two step computational model. The first step comprises of hygro-thermal model which predicts the temperature, moisture and char depth development and takes into account different initial moisture states of timber. In the second step, the response of timber beam simultaneously exposed to mechanical and fire load is determined. The mechanical model is based on the Reissner’s kinematically exact beam model and accounts for the membrane, shear and flexural deformations of the beam. Further on, material non-linear and temperature dependent behaviour is considered. In the two step model, the char front temperature is, according to Eurocode 5, assumed to have a fixed temperature of around 300°C. Based on performed study and observations, improved levels of charring rates and new thickness of zero strength layer in case of parametric fires are determined. Thus, the reduced cross section method is substantially improved to offer practical recommendations for designing fire resistance of timber structures. Furthermore, correlations between zero strength layer thickness and key input parameters of the parametric fire curve (for instance, opening factor, fire load, etc.) are given, representing a guideline for a more detailed numerical and also experimental research in the future.Keywords: advanced numerical modelling, parametric fire exposure, timber structures, zero strength layer
Procedia PDF Downloads 1603524 Prevalence and Determinants of the Use of CAM and Its Association with Quality of Life in a Sample of Lebanese Breast Cancer Patients: A Cross Sectional Study
Authors: Farah Naja, Romy Abi Fadel, Yasmin Aridi, Aya Zarif, Dania Hariri, Mohammad Alameddine, Anas Mugharbel, Maya Khalil, Zeina Nahleh, Arafat Tfayli
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The objective of this study is to assess the prevalence and determinants of CAM use among breast cancer patients in Beirut, Lebanon. A secondary objective is to evaluate the association between CAM use and quality of life (QOL). A cross-sectional survey was conducted on 180 breast cancer patients recruited from two major referral centers in Beirut. In a face to face interview, participants completed a questionnaire comprised of three sections: socio-demographic and lifestyle characteristics, breast cancer condition, and CAM use. The assessment of QOL was carried using the FACT-B Arabic version. Prevalence of CAM use since diagnosis was 40%. CAM use was negatively associated with age, treatment at a philanthropic hospital and positively associated with having an advanced stage of disease. The most commonly used CAM was ‘Special food’ followed by ‘Herbal teas’. Only 4% of CAM users cited health care professionals as influencing their choice of CAM. One in four patients disclosed CAM use to their treating physician. There was no significant association between CAM use and QOL. The use of CAM therapies among breast cancer patients is prevalent in Lebanon. Efforts should be dedicated at educating physicians to discuss CAM use with their patients and advising patients to disclose of their use with their physicians.Keywords: breast cancer, complementary and aLternative medicine, Lebanon, quality of life
Procedia PDF Downloads 5923523 Navigating the Legal Seas: The Freedom to Choose Applicable Law in Tort
Authors: Sara Vora (Hoxha)
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An essential feature of any international lawsuit is the ability of the parties to pick the law that would apply in the event of a tort claim. This option to choose the law to use in tort cases is based on Article 14 and 4/3 of the Rome II Regulation. The purpose of this article is to examine the boundaries of this freedom, as well as its relevance in international legal disputes. The article opens with a brief introduction to the basics of tort law. After a short introduction, the article demonstrates why Article 14 and 4/3 of the Rome II Regulation are so crucial to the right to select appropriate law in tort cases. The notion of the right to select the law to use in tort cases is examined, along with its breadth and possible restrictions. The article presents case studies to demonstrate how the right to select relevant law in tort might be put into practise. Case results and the judges' rationales for their rulings are examined. The possible influence of the right to select applicable law in tort on the process of harmonisation is also explored in this study. The results are summarised and the primary research question is addressed in the last section of the paper. In conclusion, the parties' ability to pick the law that rules their dispute via the freedom to choose relevant law in tort is a crucial feature of cross-border litigation. Despite certain restrictions, this freedom is nevertheless an important part of the legal structure that governs international conflicts.Keywords: applicable law, tort, Rome II regulation, freedom to choose, cross-border litigation, harmonization of tort law
Procedia PDF Downloads 593522 Tunable Optoelectronic Properties of WS₂ by Local Strain Engineering and Folding
Authors: Ahmed Raza Khan
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Local-strain engineering is an exciting approach to tune the optoelectronic properties of materials and enhance the performance of devices. Two dimensional (2D) materials such as 2D transition metal dichalcogenides (TMDCs) are particularly well-suited for this purpose because they have high flexibility and can withstand high deformations before rupture. Wrinkles on thick TMDC layers have been reported to show the interesting photoluminescence enhancement due to bandgap modulation and funneling effect. However, the wrinkles in ultrathin TMDCs have not been investigated, because the wrinkles can easily fall down to form folds in these ultrathin layers of TMDCs. Here, we have achieved both wrinkle and fold nano-structures simultaneously on 1-3L WS₂ using a new fabrication technique. The comparable layer dependent reduction in surface potential is observed for both folded layers and corresponding perfect pack layers due to the dominant interlayer screening effect. The strains produced from the wrinkle nanostructures considerably vary semi conductive junction properties. Thermo-ionic modelling suggests that the strained (1.6%) wrinkles can lower the Schottky barrier height (SBH) by 20%. The photo-generated carriers would further significantly lower the SBH. These results present an important advance towards controlling the optoelectronic properties of atomically thin WS₂ using strain engineering, with important implications for practical device applications.Keywords: strain engineering, folding, WS₂, Kelvin probe force microscopy, KPFM, surface potential, photo current, layer dependence
Procedia PDF Downloads 1033521 Assessing the Impact of the Rome II Regulation's General Rule on Cross-Border Road Traffic Accidents: A Critique of Recent Case Law
Authors: Emma Roberts
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The Rome II Regulation has established a uniform regime of conflict of law rules across the European Union (except for Denmark) which determines the law applicable in non-contractual obligations disputes. It marks a significant development towards the Europeanization of private international law and aims to provide the most appropriate connecting factors to achieve both legal certainty and justice in individual cases. Many non-contractual obligations are recognised to present such distinct factors that, to achieve these aims, a special rule is provided for determining the applicable law in cases in respect of product liability and environmental torts, for example. Throughout the legislative process, the European Parliament sought to establish a separate rule for road traffic accidents, recognising that these cases too present such novel situations that a blanket application of a lex loci damni approach would not provide an appropriate answer. Such attempts were rejected and, as a result, cases arising out of road traffic accidents are subject to the Regulation’s general lex loci damni rule along with its escape clause and limited exception. This paper offers a critique of the Regulation’s response to cross-border road traffic accident cases. In England and Wales, there have been few cases that have applied the Regulation’s provisions to date, but significantly the majority of such cases are in respect of road traffic accidents. This paper examines the decisions in those cases and challenges the legislators’ decision not to provide a special rule for such incidences. Owing to the diversity in compensation systems globally, applying the Regulation’s general rule to cases of road traffic accidents – given the breadth of matters that are to be subject to the lex cause – cannot ensure an outcome that provides ‘justice in individual cases’ as is assured by the Regulation's recitals. Not only does this paper suggest that the absence of a special rule for road traffic accidents means that the Regulation fails to achieve one of its principal aims, but it further makes out a compelling case for the legislative body of the European Union to implement a corrective instrument.Keywords: accidents abroad, applicable law, cross-border torts, non-contractual obligations, road traffic accidents
Procedia PDF Downloads 2513520 Increasing Holism: Qualitative, Cross-Dimensional Study of Contemporary Innovation Processes
Authors: Sampo Tukiainen, Jukka Mattila, Niina Erkama, Erkki Ormala
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During the past decade, calls for more holistic and integrative organizational innovation research have been increasingly voiced. On the one hand, from the theoretical perspective, the reason for this has been the tendency in contemporary innovation studies to focus on disciplinary subfields, often leading to challenges in integrating theories in meaningful ways. For example, we find that during the past three decades the innovation research has evolved into an academic field consisting of several independent research streams, such as studies on organizational learning, project management, and top management teams, to name but a few. The innovation research has also proliferated according to different dimensions of innovation, such as sources, drivers, forms, and the nature of innovation. On the other hand, from the practical perspective the rationale has been the need to develop understanding of the solving of complex, interdisciplinary issues and problems in contemporary and future societies and organizations. Therefore, for advancing theorizing, as well as the practical applicability of organizational innovation research, we acknowledge the need for more integrative and holistic perspectives and approaches. We contribute to addressing this challenge by developing a ‘box transcendent’ perspective to examine interlinkages in and across four key dimensions of organizational innovation processes, which traditionally have been studied in separate research streams. Building on an in-depth, qualitative analysis of 123 interviews of CTOs (or equivalent) and CEOs in top innovative Finnish companies as well as three in-depth case studies, both as part of an EU-level interview study of more than 700 companies, we specify interlinkages in and between i) strategic management, ii) innovation management, iii) implementation and organization, and iv) commercialization, in innovation processes. We contribute to the existing innovation research in multiple ways. Firstly, we develop a cross-dimensional, ‘box transcendent’ conceptual model at the level of organizational innovation process. Secondly, this modeling enables us to extend existing theorizing by allowing us to distinguish specific cross-dimensional innovation ‘profiles’ in two different company categories: large multinational corporations and SMEs. Finally, from the more practical perspective, we consider the implications of such innovation ‘profiles’ for the societal and institutional, policy-making development.Keywords: holistic research, innovation management, innovation studies, organizational innovation
Procedia PDF Downloads 3193519 Qsar Studies of Certain Novel Heterocycles Derived From bis-1, 2, 4 Triazoles as Anti-Tumor Agents
Authors: Madhusudan Purohit, Stephen Philip, Bharathkumar Inturi
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In this paper we report the quantitative structure activity relationship of novel bis-triazole derivatives for predicting the activity profile. The full model encompassed a dataset of 46 Bis- triazoles. Tripos Sybyl X 2.0 program was used to conduct CoMSIA QSAR modeling. The Partial Least-Squares (PLS) analysis method was used to conduct statistical analysis and to derive a QSAR model based on the field values of CoMSIA descriptor. The compounds were divided into test and training set. The compounds were evaluated by various CoMSIA parameters to predict the best QSAR model. An optimum numbers of components were first determined separately by cross-validation regression for CoMSIA model, which were then applied in the final analysis. A series of parameters were used for the study and the best fit model was obtained using donor, partition coefficient and steric parameters. The CoMSIA models demonstrated good statistical results with regression coefficient (r2) and the cross-validated coefficient (q2) of 0.575 and 0.830 respectively. The standard error for the predicted model was 0.16322. In the CoMSIA model, the steric descriptors make a marginally larger contribution than the electrostatic descriptors. The finding that the steric descriptor is the largest contributor for the CoMSIA QSAR models is consistent with the observation that more than half of the binding site area is occupied by steric regions.Keywords: 3D QSAR, CoMSIA, triazoles, novel heterocycles
Procedia PDF Downloads 4383518 Moral Distress among Nurses Working in Hospitals in Jazan: A Cross-Sectional Study
Authors: Hussain Darraj
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Background: Healthcare workers, especially nurses, are subjected to a great risk of psychological stress, mostly moral distress. Therefore, it is crucial to address moral distress in nurses. Objectives: The aim of this study is to study the extent of moral distress among hospital nurses in Jazan. Methods: This study used a cross-sectional study design, which included 419 nurses from Jazan hospitals. A questionnaire was used to measure moral distress and its related factors. Results: The average total score for moral distress among the study participants is 134.14, with a standard deviation of 53.94. Moreover, the current study findings indicate that those over the age of 35 years who work as nurse managers, working in critical departments, have the intention to leave a position, have received ethical training or workshops, have provided care for COVID-19 cases, or work in a department with staff shortages are associated with the experience of higher-level moral stress. Conclusion: Nurses are recommended to be provided with ongoing education and resources in order to reduce moral distress and create a positive work atmosphere for nurses. Moreover, the current study sheds light on the importance of organizational support to provide enough resources and staffing in order to reduce moral distress among nurses. Further research is needed to focus on other health professionals and moral distress. Moreover, future studies are also required to explore the strategies to reduce moral distress levels among nurses.Keywords: moral distress, Jazan, nurses, hospital
Procedia PDF Downloads 813517 Ultrasonic Assessment of Corpora lutea and Plasma Progesterone Levels in Early Pregnant and Non Pregnant Cows
Authors: Abdurraouf O. Gaja, Salah Y. A. Al-Dahash, Guru Solmon Raju, Chikara Kubota
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Corpus luteum cross sectional (by ultrasonography) and plasma progesterone (by DELFIA) were estimated in early pregnant and non pregnant cows on days 14th and 20th to 23rd post insemination. On day 14th, corpus luteum sectional area was 348.43 mm2 in pregnant and 387.84mm2 in non pregnant cows. Within days 20th to 23rd, corpus luteum sectional area ranged between 342.06 and 367.90 mm2 in pregnant and between 193.85 and 270.69 mm2 in non pregnant cows. Plasma progesterone level was 2.43 ng/ml in pregnant and 2.46 ng/ml in non pregnant cows on day 14th, while during days 20th to 23rd the level ranged between 2.47 and 2,84 ng/ml in pregnant and between 0.53 and 1.17 ng/ml in non pregnant cows. Results of both luteal tissue areas as well as plasma progesterone levels were highly significantly deferent (P<0.01) between pregnant and non pregnant cows during days 20th to 23rd, but there were no significant differences on day 14th. The correlation between CL cross-sectional area and plasma progesterone level was 0.4 in pregnant cows and 0.99 in non pregnant cow. It is clear, from this study, that ultrasonic assessment of corpora lutea is a viable alternative to determine plasma progesterone levels for early pregnancy diagnosis in cows.Keywords: progesterone, ultrasonography, corpus luteum, pregnancy diagnosis, cow
Procedia PDF Downloads 3033516 Predictive Analytics of Student Performance Determinants
Authors: Mahtab Davari, Charles Edward Okon, Somayeh Aghanavesi
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Every institute of learning is usually interested in the performance of enrolled students. The level of these performances determines the approach an institute of study may adopt in rendering academic services. The focus of this paper is to evaluate students' academic performance in given courses of study using machine learning methods. This study evaluated various supervised machine learning classification algorithms such as Logistic Regression (LR), Support Vector Machine, Random Forest, Decision Tree, K-Nearest Neighbors, Linear Discriminant Analysis, and Quadratic Discriminant Analysis, using selected features to predict study performance. The accuracy, precision, recall, and F1 score obtained from a 5-Fold Cross-Validation were used to determine the best classification algorithm to predict students’ performances. SVM (using a linear kernel), LDA, and LR were identified as the best-performing machine learning methods. Also, using the LR model, this study identified students' educational habits such as reading and paying attention in class as strong determinants for a student to have an above-average performance. Other important features include the academic history of the student and work. Demographic factors such as age, gender, high school graduation, etc., had no significant effect on a student's performance.Keywords: student performance, supervised machine learning, classification, cross-validation, prediction
Procedia PDF Downloads 1183515 An MrPPG Method for Face Anti-Spoofing
Authors: Lan Zhang, Cailing Zhang
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In recent years, many face anti-spoofing algorithms have high detection accuracy when detecting 2D face anti-spoofing or 3D mask face anti-spoofing alone in the field of face anti-spoofing, but their detection performance is greatly reduced in multidimensional and cross-datasets tests. The rPPG method used for face anti-spoofing uses the unique vital information of real face to judge real faces and face anti-spoofing, so rPPG method has strong stability compared with other methods, but its detection rate of 2D face anti-spoofing needs to be improved. Therefore, in this paper, we improve an rPPG(Remote Photoplethysmography) method(MrPPG) for face anti-spoofing which through color space fusion, using the correlation of pulse signals between real face regions and background regions, and introducing the cyclic neural network (LSTM) method to improve accuracy in 2D face anti-spoofing. Meanwhile, the MrPPG also has high accuracy and good stability in face anti-spoofing of multi-dimensional and cross-data datasets. The improved method was validated on Replay-Attack, CASIA-FASD, Siw and HKBU_MARs_V2 datasets, the experimental results show that the performance and stability of the improved algorithm proposed in this paper is superior to many advanced algorithms.Keywords: face anti-spoofing, face presentation attack detection, remote photoplethysmography, MrPPG
Procedia PDF Downloads 1723514 A Regression Analysis Study of the Applicability of Side Scan Sonar based Safety Inspection of Underwater Structures
Authors: Chul Park, Youngseok Kim, Sangsik Choi
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This study developed an electric jig for underwater structure inspection in order to solve the problem of the application of side scan sonar to underwater inspection, and analyzed correlations of empirical data in order to enhance sonar data resolution. For the application of tow-typed sonar to underwater structure inspection, an electric jig was developed. In fact, it was difficult to inspect a cross-section at the time of inspection with tow-typed equipment. With the development of the electric jig for underwater structure inspection, it was possible to shorten an inspection time over 20%, compared to conventional tow-typed side scan sonar, and to inspect a proper cross-section through accurate angle control. The indoor test conducted to enhance sonar data resolution proved that a water depth, the distance from an underwater structure, and a filming angle influenced a resolution and data quality. Based on the data accumulated through field experience, multiple regression analysis was conducted on correlations between three variables. As a result, the relational equation of sonar operation according to a water depth was drawn.Keywords: underwater structure, SONAR, safety inspection, resolution
Procedia PDF Downloads 259