Search results for: locking free formulation

Authors: Hechmi Saidi, Noureddine Hamdi

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The performance of hybrid amplify and forward - decode and forward (AF-DF) hybrid radio frequency/free space optical (RF/FSO) communication system, that adopts M-ary pulse position modulation (MPPM) techniques, is analyzed. Both exact and approximate symbol-error rates (SERs) are derived. The random variations of the received optical irradiance, produced by the atmospheric turbulence, is modeled by the gamma-gamma (GG) statistical distribution. A closed-form expression for the probability density function (PDF) is derived for the whole above system is obtained. Thanks to the use of hybrid AF-DF hybrid RF/FSO configuration and MPPM, the effects of atmospheric turbulence is mitigated; hence the capacity of combating atmospheric turbulence and the transmissitted signal quality are improved.

Keywords: free space optical, gamma gamma channel, radio frequency, decode and forward, error pointing, M-ary pulse position modulation, symbol error rate

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Authors: Anna Bykalyuk, Frédéric Kuznik, Kévyn Johannes

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In this paper, the influence of a vertical plate’s thermal capacity is numerically investigated in order to evaluate the evolution of the thermal boundary layer structure, as well as the convective heat transfer coefficient and the velocity and temperature profiles. Whereas the heat flux of the heated vertical plate is evaluated under time depending boundary conditions. The main important feature of this problem is the unsteadiness of the physical phenomena. A 2D CFD model is developed with the Ansys Fluent 14.0 environment and is validated using unsteady data obtained for plasterboard studied under a dynamic temperature evolution. All the phenomena produced in the vicinity of the thermal conductive vertical plate (plasterboard) are analyzed and discussed. This work is the first stage of a holistic research on transient free convection that aims, in the future, to study the natural convection in the vicinity of a vertical plate containing Phase Change Materials (PCM).

Keywords: CFD modeling, natural convection, thermal conductive plate, time-depending boundary conditions

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Authors: Armaghan Moravej Aleali, Seyed Bahman Ghaderian, Homeira Rashidi, Mahmoud Mapar

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Background and Objective The metabolic syndrome (MetS) is considered the most important public health threat of the 21st century. This syndrome is characterized by a cluster of cardiovascular risk factors including increased central abdominal obesity, elevated triglycerides, reduced high-density lipoprotein, high blood pressure, increased fasting glucose, and hyperinsulinemia. MetS has been associated with hypogonadism and erectile dysfunction (ED), and MetS may be considered a risk factor for ED. The aim of this study was finding an association between metabolic syndrome and hypogonadism in Khouzestan, Iran. Subjects and Methods: In this study, 60 patients divided into two groups consisted of 30 cases (with metabolic syndrome) and 30 controls. Total and free Serum Testosterone and FBS in all of them were measured. Data was analyzed with SPSS20 program. Results: There was a significant difference between two groups about free Testosterone (P=0.01), FBS (P=0.002) and LH (P=0.03). Conclusion: According to this finding, it is thought the prevalence of hypogonadism in men with metabolic syndrome is more than the general population.

Keywords: metabolic syndrome, fasting blood sugar, hypogonadism, testosterone

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Authors: Hooman Mehdizadeh Rad, Jai Singh

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Organic solar cells (OSCs) have been actively investigated in the last two decades due to their several merits such as simple fabrication process, low-cost manufacturing, and lightweight. In this paper, using the optical transfer matrix method (OTMM) and solving the drift-diffusion equations processes of recombination are studied in inverted and conventional bulk heterojunction (BHJ) OSCs. Two types of recombination processes are investigated: 1) recombination of free charge carriers using the Langevin theory and 2) of trapped charge carriers in the tail states with exponential energy distribution. These recombination processes are incorporated in simulating the current- voltage characteristics of both conventional and inverted BHJ OSCs. The results of this simulation produces a higher power conversion efficiency in the inverted structure in comparison with conventional structure, which agrees well with the experimental results.

Keywords: conventional organic solar cells, exponential tail state recombination, inverted organic solar cells, Langevin recombination

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Authors: Ufuk Tosun, Reza Aghazadeh, Mehmet Bülent Özer

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This study puts forward a method to analyze the sloshing characteristics of liquid in a tuned sloshing absorber system by using image processing tools. Tuned sloshing vibration absorbers have recently attracted researchers’ attention as a seismic load damper in constructions due to its practical and logistical convenience. The absorber is liquid which sloshes and applies a force in opposite phase to the motion of structure. Experimentally characterization of the sloshing behavior can be utilized as means of verifying the results of numerical analysis. It can also be used to identify the accuracy of assumptions related to the motion of the liquid. There are extensive theoretical and experimental studies in the literature related to the dynamical and structural behavior of tuned sloshing dampers. In most of these works there are efforts to estimate the sloshing behavior of the liquid such as free surface motion and total force applied by liquid to the wall of container. For these purposes the use of sensors such as load cells and ultrasonic sensors are prevalent in experimental works. Load cells are only capable of measuring the force and requires conducting tests both with and without liquid to obtain pure sloshing force. Ultrasonic level sensors give point-wise measurements and hence they are not applicable to measure the whole free surface motion. Furthermore, in the case of liquid splashing it may give incorrect data. In this work a method for evaluating the sloshing wave height by using camera records and image processing techniques is presented. In this method the motion of the liquid and its container, made of a transparent material, is recorded by a high speed camera which is aligned to the free surface of the liquid. The video captured by the camera is processed frame by frame by using MATLAB Image Processing toolbox. The process starts with cropping the desired region. By recognizing the regions containing liquid and eliminating noise and liquid splashing, the final picture depicting the free surface of liquid is achieved. This picture then is used to obtain the height of the liquid through the length of container. This process is verified by ultrasonic sensors that measured fluid height on the surface of liquid.

Keywords: fluid structure interaction, image processing, sloshing, tuned liquid damper

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Authors: Leila Mosafa, Majid Moghadam, Mohammad Shahedi

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In this work, pectinase was immobilized on the surface of silica-coated magnetite nanoparticles via covalent attachment. The magnetite-immobilized enzyme was characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy and vibrating sample magnetometry techniques. Response surface methodology using Minitab Software was applied for statistical designing of operating conditions in order to immobilize pectinase on magnetic nanoparticles. The optimal conditions were obtained at 30°C and pH 5.5 with 42.97 µl pectinase for 2 h. The immobilization yield was 50.6% at optimized conditions. Compared to the free pectinase, the immobilized pectinase was found to exhibit enhanced enzyme activity, better tolerance to the variation of pH and temperature, and improved storage stability. Both free and immobilized samples reduced the viscosity of apple juice from 1.12 to 0.88 and 0.92 mm2s-1, respectively, after 30 min at their optimum temperature. Furthermore, the immobilized enzyme could be reused six consecutive cycles and the efficiency loss in viscosity reduction was found to be only 8.16%.

Keywords: magnetite nanoparticles, pectinase enzyme, immobilization, juice clarification, enzyme activity

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Authors: Maria Margoudi, Zacharoula Smyraniou

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The current paper presents the results of a conducted case study, which was part of the author’s master thesis. During the past few years the number of children diagnosed with Learning Difficulties has drastically augmented and especially the cases of ADHD (Attention Deficit Hyperactivity Disorder). One of the core characteristics of ADHD is a deficit in working memory functions. The review of the literature indicates a plethora of educational software that aim at training and enhancing the working memory. Nevertheless, in the current paper, the possibility of using for the same purpose free, online games will be explored. Another issue of interest is the potential effect of the working memory training to the core symptoms of ADHD. In order to explore the abovementioned research questions, three digital tests are employed, all of which are developed on the E-slate platform by the author, in order to check the level of ADHD’s symptoms and to be used as diagnostic tools, both in the beginning and in the end of the case study. The tools used during the main intervention of the research are free online games for the training of working memory. The research and the data analysis focus on the following axes: a) the presence and the possible change in two of the core symptoms of ADHD, attention and impulsivity and b) a possible change in the general cognitive abilities of the individual. The case study was conducted with the participation of a thirteen year-old, female student, diagnosed with ADHD, during after-school hours. The results of the study indicate positive changes both in the levels of attention and impulsivity. Therefore we conclude that the training of working memory through the use of free, online games has a positive impact on the characteristics of ADHD. Finally, concerning the second research question, the change in general cognitive abilities, no significant changes were noted.

Keywords: ADHD, attention, impulsivity, online games

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Authors: Riccardo Patriarca, Giulio Di Gravio, Francesco Costantino, Massimo Tronci

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An accurate inventory management policy acquires a crucial role in the several high-availability sectors. In these sectors, due to the high-cost of spares and backorders, an (S-1, S) replenishment policy is necessary for high-availability items. The policy enables the shipment of a substitute efficient item anytime the inventory size decreases by one. This policy can be modelled following the Multi-Echelon Technique for Recoverable Item Control (METRIC). The METRIC is a system-based technique that allows defining the optimum stock level in a multi-echelon network, adopting measures in line with the decision-maker’s perspective. The METRIC defines an availability-cost function with inventory costs and required service levels, using as inputs data about the demand trend, the supplying and maintenance characteristics of the network and the budget/availability constraints. The traditional METRIC relies on the hypothesis that a Poisson distribution well represents the demand distribution in case of items with a low failure rate. However, in this research, we will explore the effects of using a Poisson distribution to model the demand of low failure rate items characterized by an irregular demand trend. This characteristic of a demand is not included in the traditional METRIC formulation leading to the need of revising its traditional formulation. Using the CV (Coefficient of Variation) and ADI (Average inter-Demand Interval) classification, we will define the inherent flaws of Poisson-based METRIC for irregular demand items, defining an innovative ad hoc distribution which can better fit the irregular demands. This distribution will allow defining proper stock levels to reduce stocking and backorder costs due to the high irregularities in the demand trend. A case study in the aviation domain will clarify the benefits of this innovative METRIC approach.

Keywords: METRIC, inventory management, irregular demand, spare parts

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Authors: Bita Bayatsarmadi, Shi-Zhang Qiao

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Oxygen reduction reaction (ORR) performance of iron and nitrogen co-doped porous carbon nanoparticles (Fe-NPC) with various physical and (electro) chemical properties have been investigated. Fe-NPC nanoparticles are synthesized via a facile soft-templating procedure by using Iron (III) chloride hexa-hydrate as iron precursor and aminophenol-formaldehyde resin as both carbon and nitrogen precursor. Fe-NPC nanoparticles shows high surface area (443.83 m2g-1), high pore volume (0.52 m3g-1), narrow mesopore size distribution (ca. 3.8 nm), high conductivity (IG/ID=1.04), high kinetic limiting current (11.71 mAcm-2) and more positive onset potential (-0.106 V) compared to metal-free NPC nanoparticles (-0.295V) which make it high efficient ORR metal-free catalysts in alkaline solution. This study may pave the way of feasibly designing iron and nitrogen containing carbon materials (Fe-N-C) for highly efficient oxygen reduction electro-catalysis.

Keywords: electro-catalyst, mesopore structure, oxygen reduction reaction, soft-template

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Authors: Govind Ji Pandey

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The divergent opinions in the society are important for its development but with reasonable restrictions. The world recently witnessed one of the most violent protests by a group against the editor and publisher of the magazine ‘Charlie Hebdo’ for publishing cartoon of their religious leader. The supporter of freedom of speech and expression around the world were in shock and termed it the strongest attack against the free speech. People all around the world condemned the killing of the journalists but many soft voices from several corners were also coming for reasonable restrictions on the freedom of speech and expression. Of late, Indian society has witnessed many protests and supports of films with controversial content. It is the beauty of the Indian democracy which gives an opportunity to all for discussion and debate on any issue that challenges established social norms. However, many organizations as well as individuals misuse it for their personal benefits. There have been many film directors who faced protest from several quarters for their controversial themes. This research aims at analyzing the controversial contents published in print media and shown in films. To understand the nature and frequency of such media reports, content analysis technique is used. The research also highlights the perception of the public regarding the controversies. For getting the popular opinion on the coverage of controversial content in cinema and print media, five hundred people from Lucknow, UP, India were randomly selected. The findings of this research are important to understand the response of media and society towards the controversial content presented in cinema and print media. The research highlights that how a handful of people curb free speech in a democratic country like India.

Keywords: cinema, censor board, free speech, liberty, social-religious beliefs

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Authors: Aouina Nabila Yasmina, Zine El Abidine Chaoui

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Recently, understanding the interactions of electrons with the DNA molecule and its components has attracted considerable interest because DNA is the main site damaged by ionizing radiation. The interactions of radiation with DNA induce a variety of molecular damage such as single-strand breaks, double-strand breaks, basic damage, cross-links between proteins and DNA, and others, or the formation of free radicals, which, by chemical reactions with DNA, can also lead to breakage of the strand. One factor that can contribute significantly to these processes is the effect of water hydration on the formation and reaction of radiation induced by these radicals in and / or around DNA. B-DNA requires about 30% by weight of water to maintain its native conformation in the crystalline state. The transformation depends on various factors such as sequence, ion composition, concentration and water activity. Partial dehydration converts it to DNA-A. The present study shows the results of theoretical calculations for positrons and electrons elastic scattering with DNA medium and water over a broad energy range from 10 eV to 100 keV. Indeed, electron elastic cross sections and elastic mean free paths are calculated using a corrected form of the independent atom method, taking into account the geometry of the biomolecule (SCAR macro). Moreover, the elastic scattering of electrons and positrons by atoms of the biomolecule was evaluated by means of relativistic (Dirac) partial wave analysis. Our calculated results are compared with theoretical data available in the literature in the absence of experimental data, in particular for positron. As a central result, our electron elastic cross sections are in good agreement with existing theoretical data in the range of 10 eV to 1 keV.

Keywords: elastic cross scrion, elastic mean free path, scar macro method, electron collision

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Authors: Farzaneh Badinlou, Reza Kormi-Nouri, Monika Knopf

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Enacted tasks are typically remembered better than when the same task materials are only verbally encoded, a robust finding referred to as the enactment effect. It has been assumed that enactment effect is independent of object presence but the size of enactment effect can be increased by providing objects at study phase in adults. To clarify the issues in children, free recall and cued recall performance of action phrases with or without using real objects were compared in 410 school-aged children from four age groups (8, 10, 12 and 14 years old). In this study, subjects were instructed to learn a series of action phrases under three encoding conditions, participants listened to verbal action phrases (VTs), performed the phrases (SPTs: subject-performed tasks), and observed the experimenter perform the phrases (EPTs: experimenter-performed tasks). Then, free recall and cued recall memory tests were administrated. The results revealed that the real object compared with imaginary objects improved recall performance in SPTs and EPTs, but more so in VTs. It was also found that the object presence was not necessary for the occurrence of the enactment effect but it was changed the size of enactment effect in all age groups. The size of enactment effect was more pronounced for imaginary objects than the real object in both free recall and cued recall memory tests in children. It was discussed that SPTs and EPTs deferentially facilitate item-specific and relation information processing and providing the objects can moderate the processing underlying the encoding conditions.

Keywords: action memory, enactment effect, item-specific processing, object, relational processing, school-aged children

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Authors: Ramon F. B. da Silva, Mateus Batistella, Emilio Moran

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Although the existence of two Forest Transition (FT) pathways, the economic development and the forest scarcity, there are many contexts that shape the model of FT observed in each particular region. This means that local conditions, such as relief, soil quality, historic land use/cover, public policies, the engagement of society in compliance with legal regulations, and the action of enforcement agencies, represent dimensions which combined, creates contexts that enable forest regeneration. From this perspective we can understand the regeneration process of native vegetation cover in the Paraíba Valley (Forest Atlantic biome), ongoing since the 1960s. This research analyzed public information, land use/cover maps, environmental public policies, and interviewed 17 stakeholders from the Federal and State agencies, municipal environmental and agricultural departments, civil society, farmers, aiming comprehend the contexts behind the forest regeneration in the Paraíba Valley, Sao Paulo State, Brazil. The first policy to protect forest vegetation was the Forest Code n0 4771 of 1965, but this legislation did not promote the increase of forest, just the control of deforestation, not enough to the Atlantic Forest biome that reached its highest pick of degradation in 1985 (8% of Atlantic Forest remnants). We concluded that the Brazilian environmental legislation acted in a strategic way to promote the increase of forest cover (102% of regeneration between 1985 and 2011) from 1993 when the Federal Decree n0 750 declared the initial and advanced stages of secondary succession protected against any kind of exploitation or degradation ensuring the forest regeneration process. The strategic policy formulation was also observed in the Sao Paulo State law n0 6171 of 1988 that prohibited the use of fire to manage agricultural landscape, triggering a process of forest regeneration in formerly pasture areas.

Keywords: forest transition, land abandonment, law enforcement, rural economic crisis

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Authors: Sarra Haouala, Issam Doghri

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In this work, a multiscale computational strategy is proposed for the analysis of structures, which are described at a refined level both in space and in time. The proposal is applied to two-phase viscoelastic-viscoplastic (VE-VP) reinforced thermoplastics subjected to large numbers of cycles. The main aim is to predict the effective long time response while reducing the computational cost considerably. The proposed computational framework is a combination of the mean-field space homogenization based on the generalized incrementally affine formulation for VE-VP composites, and the asymptotic time homogenization approach for coupled isotropic VE-VP homogeneous solids under large numbers of cycles. The time homogenization method is based on the definition of micro and macro-chronological time scales, and on asymptotic expansions of the unknown variables. First, the original anisotropic VE-VP initial-boundary value problem of the composite material is decomposed into coupled micro-chronological (fast time scale) and macro-chronological (slow time-scale) problems. The former is purely VE, and solved once for each macro time step, whereas the latter problem is nonlinear and solved iteratively using fully implicit time integration. Second, mean-field space homogenization is used for both micro and macro-chronological problems to determine the micro and macro-chronological effective behavior of the composite material. The response of the matrix material is VE-VP with J2 flow theory assuming small strains. The formulation exploits the return-mapping algorithm for the J2 model, with its two steps: viscoelastic predictor and plastic corrections. The proposal is implemented for an extended Mori-Tanaka scheme, and verified against finite element simulations of representative volume elements, for a number of polymer composite materials subjected to large numbers of cycles.

Keywords: asymptotic expansions, cyclic loadings, inclusion-reinforced thermoplastics, mean-field homogenization, time homogenization

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Authors: N. Santatriniaina, J. Deseure, T. Q. Nguyen, H. Fontaine, C. Beitia, L. Rakotomanana

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Nowadays, with the increasing of the wafer's size and the decreasing of critical size of integrated circuit manufacturing in modern high-tech, microelectronics industry needs a maximum attention to challenge the contamination control. The move to 300 mm is accompanied by the use of Front Opening Unified Pods for wafer and his storage. In these pods an airborne cross contamination may occur between wafers and the pods. A predictive approach using modeling and computational methods is very powerful method to understand and qualify the AMCs cross contamination processes. This work investigates the required numerical tools which are employed in order to study the AMCs cross-contamination transfer phenomena between wafers and FOUPs. Numerical optimization and finite element formulation in transient analysis were established. Analytical solution of one dimensional problem was developed and the calibration process of physical constants was performed. The least square distance between the model (analytical 1D solution) and the experimental data are minimized. The behavior of the AMCs intransient analysis was determined. The model framework preserves the classical forms of the diffusion and convection-diffusion equations and yields to consistent form of the Fick's law. The adsorption process and the surface roughness effect were also traduced as a boundary condition using the switch condition Dirichlet to Neumann and the interface condition. The methodology is applied, first using the optimization methods with analytical solution to define physical constants, and second using finite element method including adsorption kinetic and the switch of Dirichlet to Neumann condition.

Keywords: AMCs, FOUP, cross-contamination, adsorption, diffusion, numerical analysis, wafers, Dirichlet to Neumann, finite elements methods, Fick’s law, optimization

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Authors: Sonal Gupta, Rakhi Bansal, Javed Ali, Reema Gabrani, Shweta Dang

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Nanoemulsions (NEs) and microemulsions (MEs) have been an attractive tool for encapsulation of both hydrophilic and lipophillic actives. Both these systems are composed of oil phase, surfactant, co-surfactant and aqueous phase. Depending upon the application and intended use, both oil-in-water and water-in-oil emulsions can be designed. NEs are fabricated using high energy methods employing less percentage of surfactant as compared to MEs which are self assembled drug delivery systems. Owing to the nanometric size of the droplets these systems have been widely used to enhance solubility and bioavailability of natural as well as synthetic molecules. The aim of the present study is to assess the effect of % age of surfactants on cell viability of Vero cells (African Green Monkeys’ Kidney epithelial cells) via MTT assay. Green tea catechin (Polyphenon 60) loaded ME employing low energy vortexing and NE employing high energy ultrasonication were prepared using same excipients (labrasol as oil, cremophor EL as surfactant and glycerol as co-surfactant) however, the % age of oil and surfactant needed to prepare the ME was higher as compared to NE. These formulations along with their excipients (oilME=13.3%, SmixME=26.67%; oilNE=10%, SmixNE=13.52%) were added to Vero cells for 24 hrs. The tetrazolium dye, 3-(4,5-dimethylthia/ol-2-yl)-2,5-diphi-iiyltclrazolium bromide (MTT), is reduced by live cells and this reaction is used as the end point to evaluate the cytoxicity level of a test formulation. Results of MTT assay indicated that oil at different percentages exhibited almost equal cell viability (oilME ≅ oilNE) while surfactant mixture had a significant difference in the cell viability values (SmixME < SmixNE). Polyphenon 60 loaded ME and its PlaceboME showed higher toxicity as compared to Polyphenon 60 loaded NE and its PlaceboNE that can be attributed to the higher concentration of surfactants present in MEs. Another probable reason for high % cell viability of Polyphenon 60 loaded NE might be due to the effective release of Polyphenon 60 from NE formulation that helps in the sustenance of Vero cells.

Keywords: cell viability, microemulsion, MTT, nanoemulsion, surfactants, ultrasonication

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Authors: Stéphanie Pellerin, Bérengére Podvin, Luc Pastur

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In aerovehicles context, the flow around an Ahmed body profile is simulated using the velocity-vorticity formulation of the Navier-Stokes equations, associated to a penalization method for solids and Large Eddy Simulation for turbulence. The study focuses both on the ground influence on the flow and on the dissymetry of the wake, observed for a ground clearance greater than 10% of the body height H. Unsteady and mean flows are presented and analyzed. POD study completes the analysis and gives information on the most energetic structures of the flow.

Keywords: Ahmed body, bi-stability, LES, near wake

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Authors: Yao Jie, Yeo Khoon Seng

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In recent decades, flapping wing aerodynamics has attracted great interest. Understanding the physics of biological flyers such as birds and insects can help improve the performance of micro air vehicles. The present research focuses on the aerodynamics of insect-like flapping wing flight with the approach of numerical computation. Insect model of hawkmoth is adopted in the numerical study with rigid wing assumption currently. The numerical model integrates the computational fluid dynamics of the flow and active control of wing kinematics to achieve stable flight. The computation grid is a hybrid consisting of background Cartesian nodes and clouds of mesh-free grids around immersed boundaries. The generalized finite difference method is used in conjunction with single value decomposition (SVD-GFD) in computational fluid dynamics solver to study the dynamics of a free hovering hummingbird hawkmoth. The longitudinal dynamics of the hovering flight is governed by three control parameters, i.e., wing plane angle, mean positional angle and wing beating frequency. In present work, a PID controller works out the appropriate control parameters with the insect motion as input. The controller is adjusted to acquire desired maneuvering of the insect flight. The numerical scheme in present study is proven to be accurate and stable to simulate the flight of the hummingbird hawkmoth, which has relatively high Reynolds number. The PID controller is responsive to provide feedback to the wing kinematics during the hovering flight. The simulated hovering flight agrees well with the real insect flight. The present numerical study offers a promising route to investigate the free flight aerodynamics of insects, which could overcome some of the limitations of experiments.

Keywords: aerodynamics, flight control, computational fluid dynamics (CFD), flapping-wing flight

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Authors: C. F. Alegretti, F. R. Cunha, R. G. Gontijo

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This work investigates the effects of an applied magnetic field on the geometry-driven boundary layer detachment flow of a ferrofluid over a sudden expansion. Both constitutive equation and global magnetization equation for a ferrofluid are considered. Therefore, the proposed formulation consists in a coupled magnetic-hydrodynamic problem. Computational simulations are carried out in order to explore, not only the viability to control flow instabilities, but also to evaluate the consistency of theoretical aspects. The unidirectional sudden expansion in a ferrofluid flow is investigated numerically under the perspective of Ferrohydrodynamics in a two-dimensional domain using a Finite Differences Method. The boundary layer detachment induced by the sudden expansion results in a recirculating zone, which has been extensively studied in non-magnetic hydrodynamic problems for a wide range of Reynolds numbers. Similar investigations can be found in literature regarding the sudden expansion under the magnetohydrodynamics framework, but none considering a colloidal suspension of magnetic particles out of the superparamagnetic regime. The vorticity-stream function formulation is implemented and results in a clear coupling between the flow vorticity and its magnetization field. Our simulations indicate a systematic decay on the length of the recirculation zone as increasing physical parameters of the flow, such as the intensity of the applied field and the volume fraction of particles. The results all are discussed from a physical point of view in terms of the dynamical non-dimensional parameters. We argue that the decrease/reduction in the recirculation region of the flow is a direct consequence of the magnetic torque balancing the action of the torque produced by viscous and inertial forces of the flow. For the limit of small Reynolds and magnetic Reynolds parameters, the diffusion of vorticity balances the diffusion of the magnetic torque on the flow. These mechanics control the growth of the recirculation region.

Keywords: boundary layer detachment, ferrofluid, ferrohydrodynamics, magnetization, sudden expansion

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Authors: Malika El Kyal, Ahmed Machmoum

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We prove the superlinear convergence of asynchronous multi-splitting methods applied to differential equations. This study is based on the technique of nested sets. It permits to specify kind of the convergence in the asynchronous mode.The main characteristic of an asynchronous mode is that the local algorithm not have to wait at predetermined messages to become available. We allow some processors to communicate more frequently than others, and we allow the communication delays to be substantial and unpredictable. Note that synchronous algorithms in the computer science sense are particular cases of our formulation of asynchronous one.

Keywords: parallel methods, asynchronous mode, multisplitting, ODE

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Authors: Hyun-Woo Cho

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The real-time fault monitoring and diagnosis of large scale production processes is helpful and necessary in order to operate industrial process safely and efficiently producing good final product quality. Unusual and abnormal events of the process may have a serious impact on the process such as malfunctions or breakdowns. This work try to utilize process measurement data obtained in an on-line basis for the safe and some fault-free operation of industrial processes. To this end, this work evaluated the proposed intelligent process data monitoring framework based on a simulation process. The monitoring scheme extracts the fault pattern in the reduced space for the reliable data representation. Moreover, this work shows the results of using linear and nonlinear techniques for the monitoring purpose. It has shown that the nonlinear technique produced more reliable monitoring results and outperforms linear methods. The adoption of the qualitative monitoring model helps to reduce the sensitivity of the fault pattern to noise.

Keywords: process data, data mining, process operation, real-time monitoring

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Authors: Nazirah Hassan, Andrew Kendrick

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Punishment inside the penal institution has always been practiced in order to maintain discipline and keep order. Nonetheless, criminologists have long debated that the enforcement of discipline by punishing inmates is often ineffective and has a detrimental impact on inmates’ conduct. This paper uses data from a sample of 289 incarcerated young offenders to investigate the prevalence of institutional misconduct. It explores punitive cultural practices inside institutions and how this culture affects the inmates’ conduct during confinement. The project focused on male and female young offenders aged 12 to 21 years old, in eight juvenile justice institutions. The research collected quantitative and qualitative data using a mixed-method approach. All participants completed the Direct and Indirect Prisoner behavior Checklist-Scaled Version Revised (DIPC-SCALED-R). In addition, exploratory interviews were carried out with sixteen inmates and eight institutional staff. Results of the questionnaire survey show that almost half of the inmates reported a higher level of involvement in perpetration. It demonstrates a remarkable convergence of direct, rather than indirect, perpetration. Also, inmates reported a higher level of tobacco used and behavior associated with negative attitudes towards staff and institutional rules. In addition to this, the qualitative data suggests that the punitive culture encourages the onset of misconduct by increasing the stressful and oppressive conditions within the institution. In general, physical exercise and locking up inmates are two forms of punishment that were ubiquitous throughout the institutions. Interestingly, physical exercise is not only enforced by institutional staff but also inmates. These findings are discussed in terms of existing literature and their practical implications are considered.

Keywords: institutional punishment, incarcerated young offenders, punitive culture, institutional misconduct

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Authors: Oiane Ruiz de Azua, Salvador Borros, Nuria Agullo, Jordi Arbusa

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Tackiness is described as the ability to spontaneously form a bond to another material under light pressures within a short application time. During the first few minutes of the adhesive's curing, it is necessary to have enough tack to keep the substrates together while cohesion is increasing within the adhesive. This property plays a key role in the manufacturing process of pieces. Epoxy adhesives, unlike other adhesives, usually present low tackiness before curing; however, there is very little literature about the use of tackifiers in epoxy adhesives, except for the high molecular weight epoxy additives. In the present work, a tetrafunctional epoxy resin based on Bisphenol-A and Sulfanilamide has been synthesized in order to be used as a tackifier. This additive offers improved specific adhesion to two-component (2K) epoxy adhesives. The dosage of the tackifier has to be done carefully not to alter the mechanical and rheological properties of the adhesive. The synthetized product has been analyzed by FTIR and ¹H-NMR analysis, and the effect of the addition of 1 wt % of the tackifier on rheological properties, viscoelastic behavior, and mechanical properties has been studied. On one hand, the addition of the product in the epoxy resin part showed a significant increase in tackiness regarding the neat epoxy resin. On the other hand, tackiness of the whole formulation was also increased. Curing time of the adhesive has not undergone any relevant changes with the tackifier addition. Regarding viscoelastic properties, Storage Modulus (G') and Loss Modulus (G'') remain also unchanged at ambient temperature. Probably, in case higher tackifier concentration would be added, differences in viscoelastic properties would be observed. The study of mechanical properties shows that hardness and tensile strength also keep their values unchanged regarding neat two component adhesive. In conclusion, the addition of 1 wt % of sulfanilamide/epoxy enhanced the tackiness of the epoxy resin part, improves tack without modifying significantly either the rheological, the mechanical, or the viscoelastic properties of the product. Thus, the sulfanilamide presented could be a good candidate to be used as an additive to the 2k epoxy formulation for the manufacturing process of pieces.

Keywords: epoxy adhesive, manufacturing process of pieces, sulfanilamide, tackifiers

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Authors: Daniela Nedeltcheva-Antonova, Kamelia Getchovska, Vera Deneva, Stanislav Bozhanov, Liudmil Antonov

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Rosa damascena Mill. (Damask rose) is one of the most important plants belonging to the Rosaceae family, with a long historical use in traditional medicine and as a valuable oil-bearing plant. Many pharmacological effects have been reported from this plant, including anti-inflammatory, hypnotic, analgesic, anticonvulsant, anti-depressant, antianxiety, antitussive, antidiabetic, relaxant effects on tracheal chains, laxative, prokinetic and hepatoprotective activities. Pharmacological studies have shown that the various health effects of R. damascena flowers can mainly be attributed to its large amount of polyphenolic components. Phenolics possess a wide range of pharmacological activities, such as antioxidants, free-radical scavengers, anticancer, anti-inflammatory, antimutagenic, and antidepressant, with flavonoids being the most numerous group of natural polyphenolic compounds. According to the technological process in the production of rose concrete (solvent extraction with non-polar solvents of fresh rose flowers), it can be assumed that the resulting plant residue would be as rich of polyphenolics, as the plant itself, and could be used for the development of novel products with promising health-promoting effect. Therefore, an optimisation of the extraction procedure of the by-product from the rose concrete production was carried out. An assay of the extracts in respect of their total polyphenols and total flavonoids content was performed. HPLC analysis of quercetin and kaempferol, the two main flavonoids found in R. damascena, was also carried out. The preliminary results have shown that the flavonoid content in the rose extracts is comparable to that of the green tea or Gingko biloba, and they could be used for the development of various products (food supplements, natural cosmetics and phyto-pharmaceutical formulation, etc.). The fact that they are derived from the by-product of industrial plant processing could add the marketing value of the final products in addition to the well-known reputation of the products obtained from Bulgarian roses (R. damascena Mill.).

Keywords: gas chromatography-mass-spectromrtry, dry extract, flavonoids, Rosa damascena Mill

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Authors: Abolfazl Alishahi Ghalehjoughi, Bi Bi Zeinab Hoseni

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Islam is a comprehensive religion, and has rules for any thing. Islam attaches respect and importance to properties as well, and outlaws some types of transaction. A type of transaction that is strictly forbidden by the Islam is riba (usury), for which special punishments is considered in the Qur’an and hadiths. Usury is divided into (riba qarzi) loan usury and riba muamili (transaction usury); sometimes, in transaction and interest free loan contracts, ziyadah aini (interest in kind and of the same kind as that of the object of transaction) is not stipulated, but performance of work, provision of an advantage or a service, or a respite is stipulated, in which case although no ziyadah aini is in place, the transaction still constitutes usury and is outlaw. For instance, if a bank stipulates in an interest free loan contract that it pays a person the interest free loan only if he/she deposits a sum in the bank, this is an instance of riba hukmi. Or, for muamilah sarfi (transaction is which object of transaction and consideration is gold or silver) to be legitimate, it necessary that both the object of transaction and the consideration be handed over between the parties, because if a party takes delivery of the considered or object of transaction while the other party does not, the party who has taken delivery will accrue a benefit, as he/she wins time until he/she makes delivery to the other party, and this tantamount to usury in muamilah sarfi. Or, if a person lends a sum to another person, while the lender is indebted to the borrower, if the lender stipulates that he/she lends such amount only if the borrower postpones the maturity date of the lender’s debt to borrower, which is in one month, for a particular period of time, such loan will constitute usury. This research first provides views on riba hukmi, and then proceeds to analysis of views, trying to study fundamentals and proof regarding prohibition of riba hukmi, and to analyze instances of riba hukmi according to religious and hadith books.

Keywords: Islam, riba, prohibition, riba hukmi

Procedia PDF Downloads 371

Authors: Amir Zeb, Shailima Rampogu, Minky Son, Ayoung Baek, Sang H. Yoon, Keun W. Lee

Abstract:

Neurotoxic insults activate calpain, which in turn produces truncated p25 from p35. p25 forms hyperactivated Cdk5/p25 complex, and thereby induces severe neuropathological aberrations including hyperphosphorylated tau, neuroinflammation, apoptosis, and neuronal death. Inhibition of Cdk5/p25 complex alleviates aberrant phosphorylation of tau to mitigate AD pathology. PHA-793887 and Roscovitine have been investigated as selective inhibitors of Cdk5/p25 with IC50 values 5nM and 160nM, respectively, but their mechanistic studies remain unknown. Herein, computational simulations have explored the binding mode and interaction mechanism of PHA-793887 and Roscovitine with Cdk5/p25. Docking results suggested that PHA-793887 and Rsocovitine have occupied the ATP-binding site of Cdk5 and obtained highest docking (GOLD) score of 66.54 and 84.03, respectively. Furthermore, molecular dynamics (MD) simulation demonstrated that PHA-793887 and Roscovitine established stable RMSD of 1.09 Å and 1.48 Å with Cdk5/p25, respectively. Profiling of polar interactions suggested that each inhibitor formed hydrogen bonds (H-bond) with catalytic residues of Cdk5 and could remain stable throughout the molecular dynamics simulation. Additionally, binding free energy calculation by molecular mechanics/Poisson–Boltzmann surface area (MM/PBSA) suggested that PHA-793887 and Roscovitine had lowest binding free energies of -150.05 kJ/mol and -113.14 kJ/mol, respectively with Cdk5/p25. Free energy decomposition demonstrated that polar energy by H-bond between the Glu81 of Cdk5 and PHA-793887 is the essential factor to make PHA-793887 highly selective towards Cdk5/p25. Overall, this study provided substantial evidences to explore mechanistic interactions of the selective inhibitors of Cdk5/p25 and could be used as fundamental considerations in the development of structure-based selective inhibitors of Cdk5/p25.

Keywords: Cdk5/p25 inhibition, molecular modeling of Cdk5/p25, PHA-793887 and roscovitine, selective inhibition of Cdk5/p25

Procedia PDF Downloads 139

Authors: Kazeem K. Adewole

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This paper presents the finite element analysis numerical investigation of the effects of the location of across-the-width lamination on the tensile properties of rectangular wires for civil engineering applications. FE analysis revealed that the presence of the mid-thickness across-the-width lamination changes the cup and cone fracture shape exhibited by the lamination-free wire to a V-shaped fracture shape with an opening at the bottom/pointed end of the V-shape at the location of the mid-thickness across-the-width lamination. FE analysis also revealed that the presence of the mid-width across-the-thickness lamination changes the cup and cone fracture shape of the lamination-free wire without an opening to a cup and cone fracture shape with an opening at the location of the mid-width across-the-thickness lamination. The FE fracture behaviour prediction approach presented in this work serves as a tool for failure analysis of wires with lamination at different orientations which cannot be conducted experimentally.

Keywords: across-the-width lamination, tensile properties, lamination location, wire

Procedia PDF Downloads 474

Authors: Abid Hussain, Binay Kumar

Abstract:

Environment-friendly lead-free Na₀.₅₂K₀.₄₄Li₀.₀₄Nb₀.₈₄Ta₀.₁₀Sb₀.₀₆O₃ (NKLNTS) ceramic was synthesized by solid-state reaction method in search of a potential candidate to replace lead-based ceramics such as PbZrO₃-PbTiO₃ (PZT), Pb(Mg₁/₃Nb₂/₃)O₃-PbTiO₃ (PMN-PT) etc., for various applications. The ceramic was calcined at temperature 850 ᵒC and sintered at 1090 ᵒC. The powder X-Ray Diffraction (XRD) pattern revealed the formation of pure perovskite phase having tetragonal symmetry with space group P4mm of the synthesized ceramic. The surface morphology of the ceramic was studied using Field Emission Scanning Electron Microscopy (FESEM) technique. The well-defined grains with homogeneous microstructure were observed. The average grain size was found to be ~ 0.6 µm. A very large value of piezoelectric charge coefficient (d₃₃ ~ 754 pm/V) was obtained for the synthesized ceramic which indicated its potential for use in transducers and actuators. In dielectric measurements, a high value of ferroelectric to paraelectric phase transition temperature (Tm~305 ᵒC), a high value of maximum dielectric permittivity ~ 2110 (at 1 kHz) and a very small value of dielectric loss ( < 0.6) were obtained which suggested the utility of NKLNTS ceramic in high-temperature ferroelectric devices. Also, the degree of diffuseness (γ) was found to be 1.61 which confirmed a relaxor ferroelectric behavior in NKLNTS ceramic. P-E hysteresis loop was traced and the value of spontaneous polarization was found to be ~11μC/cm² at room temperature. The pyroelectric coefficient was obtained to be very high (p ∼ 1870 μCm⁻² ᵒC⁻¹) for the present case indicating its applicability in pyroelectric detector applications including fire and burglar alarms, infrared imaging, etc. NKLNTS ceramic showed fatigue free behavior over 107 switching cycles. Remanent hysteresis task was performed to determine the true-remanent (or intrinsic) polarization of NKLNTS ceramic by eliminating non-switchable components which showed that a major portion (83.10 %) of the remanent polarization (Pr) is switchable in the sample which makes NKLNTS ceramic a suitable material for memory switching devices applications. Time-Dependent Compensated (TDC) hysteresis task was carried out which revealed resistive leakage free nature of the ceramic. The performance of NKLNTS ceramic was found to be superior to many lead based piezoceramics and hence can effectively replace them for use in piezoelectric, pyroelectric and long duration ferroelectric applications.

Keywords: dielectric properties, ferroelectric properties , lead free ceramic, piezoelectric property, solid state reaction, true-remanent polarization

Procedia PDF Downloads 136

Authors: Soultana Konstantinidou, Tiziana Schmidt, Elena Landi, Alessandro De Carli, Giovanni Maltinti, Darius Witt, Alicja Dziadosz, Agnieszka Lindstaedt, Michele Lai, Mauro Pistello, Valentina Cappello, Luciana Dente, Chiara Gabellini, Piotr Barski, Vittoria Raffa

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CRISPR/Cas9 technology has gained the interest of researchers in the field of biotechnology for genome editing. Since its discovery as a microbial adaptive immune defense, this system has been widely adopted and is acknowledged for having a variety of applications. However, critical barriers related to safety and delivery are persisting. Here, we propose a new concept of genome engineering, which is based on a nano-formulation of Cas9. The Cas9 enzyme was conjugated to a gold nanoparticle (AuNP-Cas9). The AuNP-Cas9 maintained its cleavage efficiency in vitro, to the same extent as the ribonucleoprotein, including non-conjugated Cas9 enzyme, and showed high gene editing efficiency in vivo in zebrafish embryos. Since CRISPR/Cas9 technology is extensively used in cancer research, melanoma was selected as a validation target. Cell studies were performed in A375 human melanoma cells. Particles per se had no impact on cell metabolism and proliferation. Intriguingly, the AuNP-Cas9 internalized spontaneously in cells and localized as a single particle in the cytoplasm and organelles. More importantly, the AuNP-Cas9 showed a high nuclear localization signal. The AuNP-Cas9, overcoming the delivery difficulties of Cas9, could be used in cellular biology and localization studies. Taking advantage of the plasmonic properties of gold nanoparticles, this technology could potentially be a bio-tool for combining gene editing and photothermal therapy in cancer cells. Further work will be focused on intracellular interactions of the nano-formulation and characterization of the optical properties.

Keywords: CRISPR/Cas9, gene editing, gold nanoparticles, nanotechnology

Procedia PDF Downloads 101

Authors: Shima Taheri, Simon Clark

Abstract:

Concrete is an essential building material used in the majority of structures. Degradation of concrete over time increases the life-cycle cost of an asset with an estimated annual cost of billions of dollars to national economies. Most of the concrete failure occurs due to cracks, which propagate through a structure and cause weakening leading to failure. Stopping crack propagation is thus the key to protecting concrete structures from failure and is the best way to prevent inconveniences and catastrophes. Furthermore, the majority of cracks occur deep within the concrete in inaccessible areas and are invisible to normal inspection. Few materials intrinsically possess self-healing ability, but one that does is concrete. However, self-healing in concrete is limited to small dormant cracks in a moist environment and is difficult to control. In this project, we developed a method for self-healing of nascent fractures in concrete components through the automatic release of self-curing healing agents encapsulated in breakable nano- and micro-structures. The Poly(methyl methacrylate) (PMMA) based two-part adhesive is encapsulated in core-shell structures with brittle/weak inert shell, synthesized via miniemulsion/solvent evaporation polymerization. Stress fields associated with propagating cracks can break these capsules releasing the healing agents at the point where they are needed. The shell thickness is playing an important role in preserving the content until the final setting of concrete. The capsules can also be surface functionalized with carboxyl groups to overcome the homogenous mixing issues. Currently, this formulated self-healing system can replace up to 1% of cement in a concrete formulation. Increasing this amount to 5-7% in the concrete formulation without compromising compression strength and shrinkage properties, is still under investigation. This self-healing system will not only increase the durability of structures by stopping crack propagation but also allow the use of less cement in concrete construction, thereby adding to the global effort for CO2 emission reduction.

Keywords: self-healing concrete, concrete crack, concrete deterioration, durability

Procedia PDF Downloads 117