Search results for: physical parameters

Authors: Baya Takhedmit, Karim Abbas, Sofiane Ouazine

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The vacations queues are often employed to model many real situations such as computer systems, communication networks, manufacturing and production systems, transportation systems and so forth. These queueing models are solved at fixed parameters values. However, the parameter values themselves are determined from a finite number of observations and hence have uncertainty associated with them (epistemic uncertainty). In this paper, we consider the M/G/1/N queue with server vacation and exhaustive discipline where we assume that the vacation parameter values have uncertainty. We use the Taylor series expansions approach to estimate the expectation and variance of model output, due to epistemic uncertainties in the model input parameters.

Keywords: epistemic uncertainty, M/G/1/N queue with vacations, non-parametric sensitivity analysis, Taylor series expansion

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Authors: H. Mohammadi Majd, M. Jalali Azizpour, V. Tavaf, A. Jaderi

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In upsetting processes contact friction significantly influence metal flow, stress-strain state and process parameters. Furthermore, tribological conditions influence workpiece deformation and its dimensional precision. A viscoplastic constitutive law, the Anand model, was applied to represent the inelastic deformation behavior in upsetting process. This paper presents research results of the influence of contact friction coefficient on a workpiece deformation in upsetting process.finite element parameters. This technique was tested for three different specimens simulations of the upsetting and the corresponding material and can be successfully employed to predict the deformation of the upsetting process.

Keywords: friction, upsetting, barreling, Anand model

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Authors: Shruti Sakarkar, Jega Jegatheesan, Srinivasan Madapusi

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Photocatalytic membranes have shown great potential for the removal of an organic and inorganic pollutant from wastewater as it combines the degradation and antibacterial properties from photocatalysis and physical separation by the membrane in a single unit. Incorporation of the semiconductor in membrane structure results in enhancing the performance and the properties of the membrane. In this study porous ultrafiltration polyvinylidene fluoride (PVDF) membranes with entrapped TiO₂ nanoparticle were prepared by phase inversion method and further used for the degradation of reactive orange 16 (RO16). Prepared photocatalytic membranes were characterized by the scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), contact angle, and atomic force microscope (AFM). The addition of TiO₂ nanopartparticles improves the strength and thermal stability of the membrane. In particular hydrophilicity and permeability increases with the increase of TiO₂ nanoparticles into the membrane. The photocatalytic membrane achieves 80-85% degrdation of RO16. The impact of different parameters such as pH, concentration of photocatalyst, dye concentration and effect of H₂O₂ were analysed. The best conditions for dye degradation were an initial dye concentration of 50 mg/L, with a membrane containing TiO₂ loading of 2wt%. It was observed that in the presence of H₂O₂, degradation increases with increasing H₂O₂ concentration and reached up to 95-98%. The high quality permeates obtained from the photocatalytic membrane can be reused.

Keywords: photocatalytic membrane, TiO₂, PVDF, nanoparticles

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Authors: Sanjay Singh, Parameswara Rao Vuddanda

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The aim of the present study is study the factual benefit of nano size and surface coating of p-gp efflux inhibitor on enhancement of bioavailability of Berberine chloride (BBR); a p-gp substrate. In addition, 28 days sub acute oral toxicity study was also conducted to assess the toxicity of the formulation on chronic administration. BBR loaded polymeric nanoparticles (BBR-NP) were prepared by nanoprecipitation method. BBR NP were surface coated (BBR-SCNP) with the 1 % w/v of vitamin E TPGS. For bioavailability study, total five groups (n=6) of rat were treated as follows first; pure BBR, second; physical mixture of BBR, carrier and vitamin E TPGS, third; BBR-NP, fourth; BBR-SCNP and fifth; BBR and verapamil (widely used p-gp inhibitor). Blood was withdrawn at pre-set timing points in 24 hrs study and drug was quantified by HPLC method. In oral chronic toxicity study, total four groups (n=6) were treated as follows first (control); water, second; pure BBR, third; BBR surface coated nanoparticles and fourth; placebo BBR surface coated nanoparticles. Biochemical levels of liver (AST, ALP and ALT) and kidney (serum urea and creatinine) along with their histopathological studies were also examined (0-28 days). The AUC of BBR-SCNP was significantly 3.5 folds higher compared to all other groups. The AUC of BBR-NP was 3.23 and 1.52 folds higher compared to BBR solution and BBR with verapamil group, respectively. The physical mixture treated group showed slightly higher AUC than BBR solution treated group but significantly low compared to other groups. It indicates that encapsulation of BBR in nanosize form can circumvent P-gp efflux effect. BBR-NP showed pharmacokinetic parameters (Cmax and AUC) which are near to BBR-SCNP. However, the difference in values of T1/2 and clearance indicate that surface coating with vitamin E TPGS not only avoids the P-gp efflux at its absorption site (intestine) but also at organs which are responsible for metabolism and excretion (kidney and liver). It may be the reason for observed decrease in clearance of BBR-SCNP. No toxicity signs were observed either in biochemical or histopathological examination of liver and kidney during toxicity studies. The results indicate that administration of BBR in surface coated nanoformulation would be beneficial for enhancement of its bioavailability and longer retention in systemic circulation. Further, sub acute oral dose toxicity studies for 28 days such as evaluation of intestine, liver and kidney histopathology and biochemical estimations indicated that BBR-SCNP developed were safe for long use.

Keywords: bioavailability, berberine nanoparticles, p-gp efflux inhibitor, nanoprecipitation method

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Authors: Narges Shayesteh Moghaddam

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Tungsten (W), a refractory metal known for its remarkably high melting temperature, offers tremendous potential for use in challenging environments prevalent in sectors such as space exploration, defense, and nuclear industries. Additive manufacturing, especially the Laser Powder-Bed Fusion (LPBF) technique, emerges as a beneficial method for fabricating tungsten parts. This technique enables the production of intricate components while simultaneously reducing production lead times and associated costs. However, the inherent brittleness of tungsten and its tendency to crack under high-temperature conditions pose significant challenges to the manufacturing process. Our research primarily focuses on the process of rolling tungsten parts in a layer-by-layer manner in LPBF and the subsequent changes in microstructure. Our objective is not only to identify the alterations in the microstructure but also to assess their implications on the physical properties and performance of the fabricated tungsten parts. To examine these aspects, we conducted an extensive series of experiments that included the fabrication of tungsten samples through LPBF and subsequent characterization using advanced materials analysis techniques. These investigations allowed us to scrutinize shifts in various microstructural features, including, but not limited to, grain size and grain boundaries occurring during the rolling process. The results of our study provide crucial insights into how specific factors, such as plastic deformation occurring during the rolling process, influence the microstructural characteristics of the fabricated parts. This information is vital as it provides a foundation for understanding how the parameters of the layer-by-layer rolling process affect the final tungsten parts. Our research significantly broadens the current understanding of microstructural evolution in tungsten parts produced via the layer-by-layer rolling process in LPBF. The insights obtained will play a pivotal role in refining and optimizing manufacturing parameters, thus improving the mechanical properties of tungsten parts and, therefore, enhancing their performance. Furthermore, these findings will contribute to the advancement of manufacturing techniques, facilitating the wider application of tungsten parts in various high-demand sectors. Through these advancements, this research represents a significant step towards harnessing the full potential of tungsten in high-temperature and high-stress applications.

Keywords: additive manufacturing, rolling, tungsten, refractory materials

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Authors: Jamuna Konda, Umamaheswara Reddy Karumuri, Sriramya Muthugi, Varun Pishati, Ravi Shakya,

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This paper investigates the challenges involved in mathematical modeling of plant simulation models ensuring the performance of the plant models much closer to the real time physical model. The paper includes the analysis performed and investigation on different methods of modeling, design and development for plant model. Issues which impact the design time, model accuracy as real time model, tool dependence are analyzed. The real time hardware plant would be a combination of multiple physical models. It is more challenging to test the complete system with all possible test scenarios. There are possibilities of failure or damage of the system due to any unwanted test execution on real time.

Keywords: model based design (MBD), MATLAB, Simulink, stateflow, plant model, real time model, real-time workshop (RTW), target language compiler (TLC)

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Authors: Muntadher Sallal, Gareth Owenson, Mo Adda, Safa Shubbar

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Bitcoin is a digital currency based on a peer-to-peer network to propagate and verify transactions. Bitcoin is gaining wider adoption than any previous crypto-currency. However, the mechanism of peers randomly choosing logical neighbors without any knowledge about underlying physical topology can cause a delay overhead in information propagation, which makes the system vulnerable to double-spend attacks. Aiming at alleviating the propagation delay problem, this paper introduces proximity-aware extensions to the current Bitcoin protocol, named Master Node Based Clustering (MNBC). The ultimate purpose of the proposed protocol, that are based on how clusters are formulated and how nodes can define their membership, is to improve the information propagation delay in the Bitcoin network. In MNBC protocol, physical internet connectivity increases, as well as the number of hops between nodes, decreases through assigning nodes to be responsible for maintaining clusters based on physical internet proximity. We show, through simulations, that the proposed protocol defines better clustering structures that optimize the performance of the transaction propagation over the Bitcoin protocol. The evaluation of partition attacks in the MNBC protocol, as well as the Bitcoin network, was done in this paper. Evaluation results prove that even though the Bitcoin network is more resistant against the partitioning attack than the MNBC protocol, more resources are needed to be spent to split the network in the MNBC protocol, especially with a higher number of nodes.

Keywords: Bitcoin network, propagation delay, clustering, scalability

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Authors: Cecilia Elisabeth Fåhraeus

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In 2016, this author conducted a study on agricultural livelihoods in urban and peri-urban low-income settings in Lusaka, Zambia. The overarching aim was to determine the impact of physical space on agricultural activities, with a particular emphasis on geographical distinctions between urban and peri-urban environments. Agricultural activities among the areas’ residents were mapped through questionnaires, interviews and observations, and included variables such as type of activity and product; degree of marketization; inputs; location of production, storage and vending; labour distribution; production constraints, and associated mobility patterns, among others. The study confirmed that spatial idiosyncrasies of urban and peri-urban environments both enabled and constrained agricultural activity, but not always as anticipated. There were also cross-cutting issues on which physical space appeared to have a limited impact.

Keywords: agricultural production systems, geography, low-income settlements, Lusaka, peri-urban, urban

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Authors: Noemia Gomes de Mattos de Mesquita, José Eduardo Ferreira de Oliveira, Arimatea Quaresma Ferraz

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Stops to exchange cutting tool, to set up again the tool in a turning operation with CNC or to measure the workpiece dimensions have a direct influence on production. The premature removal of the cutting tool results in high cost of machining since the parcel relating to the cost of the cutting tool increases. On the other hand, the late exchange of cutting tool also increases the cost of production because getting parts out of the preset tolerances may require rework for its use when it does not cause bigger problems such as breaking of cutting tools or the loss of the part. Therefore, the right time to exchange the tool should be well defined when wanted to minimize production costs. When the flank wear is the limiting tool life, the time predetermination that a cutting tool must be used for the machining occurs within the limits of tolerance can be done without difficulty. This paper aims to show how the life of the cutting tool can be calculated taking into account the cutting parameters (cutting speed, feed and depth of cut), workpiece material, power of the machine, the dimensional tolerance of the part, the finishing surface, the geometry of the cutting tool and operating conditions of the machine tool, once known the parameters of Taylor algebraic structure. These parameters were raised for the ABNT 1038 steel machined with cutting tools of hard metal.

Keywords: machining, productions, cutting condition, design, manufacturing, measurement

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Authors: Patricia P. M. C. Lourenço

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South Korean Entertainment Industry has reversed the gender binary through Beast and Beauty Korean dramas that perpetuate Korean unrealistic beauty standards by emphasizing freckles, acne, pimples, excessive weight, fizzy hair, glasses, and braces as ugly and unattractive, therefore in need of correction to fit into society’s pre-established beauty mould. This pursuit of physical beauty as a happiness goal only detracts singularity in favour of mundaneness, sustaining the illusion that unsightly women need to undergo a physical transformation to improve their lives while handsome, wealthy men need not do anything more than altruistically accept them for who they really are inside. Five Beast and Beauty dramas were analysed for this paper. The assessment revealed that there is standardization and typecasting of Beast and Beauty roles in K-Dramas, a reflection of South Korean’s patriarchal society where women and men are continuously expected to fulfil their pre-established gender binary roles and stereotypes.

Keywords: K-dramas, beauty, low self-esteem, plastic surgery, South Korean stereotypes

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Authors: Ghasem Sharifi, Hamed Shahmohamadi Ousaloo, Milad Azimi, Mehran Mirshams

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The ever-increasing use of satellites demands a search for increasingly accurate and reliable pointing systems. Reaction wheels are rotating devices used commonly for the attitude control of the spacecraft since provide a wide range of torque magnitude and high reliability. The numerical modeling of this device can significantly enhance the accuracy of the satellite control in space. Modeling the wheel rotation in the presence of the various frictions is one of the critical parts of this approach. This paper presents a Dynamic Model Control of a Reaction Wheel (DMCR) in the current control mode. In current-mode, the required current is delivered to the coils in order to achieve the desired torque. During this research, all the friction parameters as viscous and coulomb, motor coefficient, resistance and voltage constant are identified. In order to model identification of a reaction wheel, numerous varying current commands apply on the particular wheel to verify the estimated model. All the parameters of DMCR are identified by classical Levenberg-Marquardt (CLM) optimization method. The experimental results demonstrate that the developed model has an appropriate precise and can be used in the satellite control simulation.

Keywords: experimental modeling, friction parameters, model identification, reaction wheel

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Authors: Andrej Pilipović, Branislav Kovačević, Marina Milović, Lazar Kesić, Saša Pekeč, Leopold Poljaković-Pajnik, Saša Orlović

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The effect of landfills on the environment reflects in the dispersion of the contaminants on surrounding soils by the groundwater plume. Such negative effect can be mitigated with the establishment of vegetative buffers surrounding landfills. The “TreeRemEnergy” project funded by the Science Fund of Republic of Serbia – Green program focuses on development of phytobuffers for landfill phytoremediation with the use of Short Rotation Woody Crops (SRWC) plantations that can be further used for the biomass for energy. One of the goals of the project is to select most appropriate poplar (Populus sp.) and willow (Salix sp.) clones through phytorecurrent selection that involves testing of various breeding traits. Physiological parameters serve as a significant contribution to the breeding process aimed to early detection of potential candidates. This study involved testing of the effect of the landfill soils on the photosynthetic processes of the selected poplar and willow candidates. For this purpose, measurements of the gas exchange, chlorophyll content and chlorophyll fluorescence were measured on the tested plants. Obtained results showed that there were differences in the influence of the controlled sources of variation on examined physiological parameters. The effect of clone was significant in all parameters, while the effect of the substrate was not statistically significant in any of measured parameters. However, the effect of interaction Clone×Substrate was significant in intercellular CO2 concentration(ci), stomatal conductance (gs) and transpiration rate (E), suggesting that water regime of the tested clones showed different response to the tested soils. Some clones showed more “generalist” behavior (380, 107/65/9, and PE19/66), while “specialist” behavior was recorded in clones PE4/68, S1-8, and 79/64/2. On the other hand, there was no significant effect of the tested substrate on the pigments content measured with SPAD meter. Results of this study allowed us to narrow the group of clones for further trails in field conditions.

Keywords: clones, net photosynthesis, WUE, transpiration, stomatal conductance, SPAD

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Authors: Kaouther Selmi, Alaeddine Sridi, Mohamed Bouallegue, Kais Bouallegue

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Neurons are the fundamental units of the brain and the nervous system. The variable structure model of neurons consists of a system of differential equations with various parameters. By optimizing these parameters, we can create a unique model that describes the dynamic behavior of a single neuron. We introduce a neural network based on neurons with multiple dendrites employing an activation function with a variable structure. In this paper, we present a model for heart behavior. Finally, we showcase our successful simulation of the heart's ECG diagram using our Variable Structure Neuron Model (VSMN). This result could provide valuable insights into cardiology.

Keywords: neural networks, neuron, dendrites, heart behavior, ECG

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Authors: M. Stefanovska, B. Samakoski, S. Risteska, G. Maneski

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In this study was performed in situ consolidation of polypropylene matrix/glass reinforced roving by combining heating systems and roll pressing. The commingled roving during hoop winding was winded on a cylindrical mandrel. The work also presents the advances made in the processing of these materials into composites by conventional technique filament winding. Experimental studies were performed with changing parameters – temperature, pressure and speed. Finally, it describes the investigation of the optimal processing conditions that maximize the mechanical properties of the composites. These properties are good enough for composites to be used as engineering materials in many structural applications.

Keywords: commingled fiber, consolidation heat, filament winding, voids

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Authors: Samvel H. Sargsyan

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Together with the study of electron-optical properties of nanostructures and proceeding from experiment-based data, the study of the mechanical properties of nanostructures has become quite actual. For the study of the mechanical properties of fullerene, carbon nanotubes, graphene and other nanostructures one of the crucial issues is the construction of their adequate mathematical models. Among all mathematical models of graphene or carbon nano-tubes, this so-called discrete-continuous model is specifically important. It substitutes the interactions between atoms by elastic beams or springs. The present paper demonstrates the construction of the discrete-continual beam model for carbon nanotubes or graphene, where the micropolar beam model based on the theory of moment elasticity is accepted. With the account of the energy balance principle, the elastic moment constants for the beam model, expressed by the physical and geometrical parameters of carbon nanotube or graphene, are determined. By switching from discrete-continual beam model to the continual, the models of micropolar elastic cylindrical shell and micropolar elastic plate are confirmed as continual models for carbon nanotube and graphene respectively.

Keywords: carbon nanotube, discrete-continual, elastic, graphene, micropolar, plate, shell

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Authors: Marium Shaikh, Tahira M. Ali, Abid Hasnain

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Physical and sensory properties of white sauces prepared from native and chemically modified corn and pearl millet starches were compared. Interestingly, no syneresis was observed in hydroxypropylated corn and pearl millet starch containing white sauce even after nine days of cold storage (4 °C), while other modifications also reduced the syneresis significantly in comparison to their native counterparts. White sauce containing succinylated corn starch showed least oil separation due to its greater emulsion stability. Light microscopy was used to visualize the size and shape of fat globules, and it was found that they were most homogenously distributed in succinylated and hydroxypropylated samples. Sensory results revealed that chemical modification of corn and pearl millet starch improved the consistency, thickness and overall acceptability of white sauces. Viscosity profiles showed that pasting parameters of native pearl millet starch are almost similar to native corn starch suggesting pearl millet starch as an alternative of corn starch. Also, white sauce prepared from modified pearl millet starch showed better cold storage stability in terms of various textural attributes like hardness, cohesiveness, chewiness, and springiness.

Keywords: corn starch, pearl millet, hydroxypropylation, succinylation, white sauce

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Authors: Lukman Andi Priyatna, Vivi Fauzia, Ferry Anggoro Ardy Nugroho

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Zinc oxide (ZnO) based nanostructures are ubiquitous in applications due to their favourable physicochemical properties and ease of fabrication. One widely accessible route to synthesize ZnO nanorods, which show promising performance in e.g. photoelectrochemical water splitting, is hydrothermal growth of ZnO seeds, obtained via an atomic nebulizer. Despite its popularity, study on the impact of the synthesis parameters in atomic nebulizer on the performance of the synthesized ZnO nanostructures is lacking. This study presents an investigation on the impact of the distance between substrates and atomic nebulizer nozzle on the photoelectrochemical water splitting performance of ZnO nanorods. Adjusting such a distance reveals an optimum separation which results in nanostructures with highest absorbance. Such high absorbance translates into improved photoelectrochemistry, as evaluated by higher photocurrent density, from 0.11 mA/cm² to 0.14 mA/cm² and higher Applied Bias Photon-to-Current Efficiency (ABPE) from 0.12% to 0.14%. These results underscore the importance of understanding and optimizing the experimental parameters during ZnO nanostructure synthesis. In a broader context, it advertises the need to carefully assess the corresponding fabrication parameters to optimize the performance of the obtained nanostructures.

Keywords: atomic nebulizer, photocurrent density, photoelectrochemical water splitting, ZnO nanorods

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Authors: Shubeska Stratrova S., Muca A., Panovska S. Clinic of endocrinology, diabetes, metabolic disorders, Medical Faculty, Skopje, N. Macedonia

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Rationale: Obese subjects have a high energy density diet, low physical activity levels, a sedentary lifestyle, as well as eating disorders, which are considered important risk factors for the development of obesity. Methods: In order to discover the imbalance of energy intake and energy expenditure in obese women (W), two groups of examinees answered questionnaires regarding nutrition and physical activity: 1st group of women with normal body mass index (BMI <25 kg/m²) and 2nd group of obese women with BMI >30 kg/m². Results: 61.11% of obese W from the 2nd group reported good appetite, which was higher than the 1st group (45%). In 55.56% W, frustrations were a provocation for over nutrition. In the 2nd group, 38.89% W ate too much compared to 9.09% W from the 1st group. In the ²ⁿᵈ group, 35.29% W reported consuming food rarely and too much, while 29.41% W reported consuming food often and too much. All examinees from the ²ⁿᵈ group had consumed food in less than 5 hours, compared to only 8.33% W from the ¹ⁿᵈ group and had consumed hyper-caloric food. Consumption of fruits and vegetables was lower in the 2nd group compared to the 1st group. Half of the subjects in the 2nd group were physically inactive, compared to only 8% in the 1st group. All of the examinees in the 2nd group walked for less than 3 hours a day, compared to 54% in the 1st group. In the 2nd group, 67% W reported watching TV very often, 39% reported watching TV longer than 3 hours, which is significantly higher than 8.33% W in the 1st group. Overall, 81.25% of examinees from the 2nd group reported sitting for more than 3 hours a day, which is significantly more compared to the 1st group (45.45%). Conclusions: Obese women are less physically active, have a sedentary lifestyle, good appetite, and consume too much hyper-caloric food very often.

Keywords: (W) obese women, BMI(Body mass Index), nutrition, hyper-caloric food

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Authors: Nandhini Ravi, Muthukumaran Shanmugam

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Metals are being replaced by thermoplastic polymer composites in automotive industries because of their low density, easiness to fabricate, low cost and good wear resistance. Complex polymer components consist of assemblies of smaller parts which can be joined by friction stir welding. This study deals with the additive friction stir welding of 15 wt.% glass fiber reinforced polyamide 66 composite which is a modified technique of the conventional friction stir welding by the addition of a filler plate for the heating of the composite work piece through the tool during the welding process. Welding at different combinations of tool rotational speed, travel speed and tool plunge depth was done after which the tensile strength of the respective experiments was determined. The maximum tensile strength obtained was 77 MPa which was 80% of the strength of the base material. The process parameters were optimized using the L9 orthogonal array and also the effect of individual welding parameter on the tensile strength was studied. The optimum parameter combination was determined with the help of ANOVA studies. The hardness of the welded joints was studied with the help of Shore Durometer which yielded the maximum of D 75.

Keywords: additive friction stir welding, polyamide 66, process parameters, thermoplastic polymer composite

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Authors: Tugba Bayoglu

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Aerodynamic parameter estimation is very crucial in missile design phase, since accurate high fidelity aerodynamic model is required for designing high performance and robust control system, developing high fidelity flight simulations and verification of computational and wind tunnel test results. However, in literature, there is not enough missile aerodynamic parameter identification study for three main reasons: (1) most air to air missiles cannot fly with constant speed, (2) missile flight test number and flight duration are much less than that of fixed wing aircraft, (3) variation of the missile aerodynamic parameters with respect to Mach number is higher than that of fixed wing aircraft. In addition to these challenges, identification of aerodynamic parameters for high wind angles by using classical estimation techniques brings another difficulty in the estimation process. The reason for this, most of the estimation techniques require employing polynomials or splines to model the behavior of the aerodynamics. However, for the missiles with a large variation of aerodynamic parameters with respect to flight variables, the order of the proposed model increases, which brings computational burden and complexity. Therefore, in this study, it is aimed to solve nonlinear aerodynamic parameter identification problem for a supersonic air to air missile by using Artificial Neural Networks. The method proposed will be tested by using simulated data which will be generated with a six degree of freedom missile model, involving a nonlinear aerodynamic database. The data will be corrupted by adding noise to the measurement model. Then, by using the flight variables and measurements, the parameters will be estimated. Finally, the prediction accuracy will be investigated.

Keywords: air to air missile, artificial neural networks, open loop simulation, parameter identification

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Authors: Joseph Mouallem, Seyed Reza Amini Niaki, Norman Chavez-Cussy, Christian Costa Milioli, Fernando Eduardo Milioli

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Sub-grid closures for filtered two-fluid models (fTFM) useful in large scale simulations (LSS) of riser flows can be derived from highly resolved simulations (HRS) with microscopic two-fluid modeling (mTFM). Accurate sub-grid closures require accurate mTFM formulations as well as accurate correlation of relevant filtered parameters to suitable independent variables. This article deals with both of those issues. The accuracy of mTFM is touched by assessing the impact of gas sub-grid turbulence over HRS filtered predictions. A gas turbulence alike effect is artificially inserted by means of a stochastic forcing procedure implemented in the physical space over the momentum conservation equation of the gas phase. The correlation issue is touched by introducing a three-filtered variable correlation analysis (three-marker analysis) performed under a variety of different macro-scale conditions typical or risers. While the more elaborated correlation procedure clearly improved accuracy, accounting for gas sub-grid turbulence had no significant impact over predictions.

Keywords: fluidization, gas-particle flow, two-fluid model, sub-grid models, filtered closures

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Authors: Alireza Jafarzadeh, Bahram Amu-Oqhli Tabrizi, Hadi Khayat Nouri, Arash Khaki

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30 head of adult Vistar rats were chosen to evaluate the chronic narcotic effects of crack on some biochemical parameters. The rats weighted approximately 200 to 250 g. They were divided into 5 groups of 6 and were housed in identical condition in terms of food and ambience. Rats were maintained at 12 hours light and 12 hours darkness. Rats were injected 7.8 mg/kg BW crack intraperitoneally. The groups one to four received daily medication for one to four weeks respectively. The control groups were injected identical dose of saline. The blood was taken from control and test groups then serum was separated from. Serum biochemical parameters of amylase, lipase, triglycerides, cholesterol, HDL, LDL, VLDL, protein and albumin were measured by diagnostic kits. Serum protein and albumin levels did not show statistically significant changes. Serum lipase and amylase showed significant changes both of which were increased. The serum levels of cholesterol, LDL and HDL demonstrated no significant changes. Triglycerides values showed a significant increase in serum. Serum VLDL in groups 3 and 4 exhibited significant changes compare to other groups.

Keywords: albumin, amylase, cholesterol, crack, HDL, LDL, lipase, protein, rat, triglycerides, VLDL

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Authors: Abigail Bentley, Audrey Prost, Nayreen Daruwalla, Apoorwa Gupta, David Osrin

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BACKGROUND: Intimate partner violence (IPV) can impact a woman’s physical, reproductive and mental health, including common mental disorders such as anxiety and depression. However, people other than an intimate partner may also perpetrate violence against women in the family, particularly in India. This study aims to investigate the relationship between experiences of violence perpetrated by the husband and other members of the wider household and symptoms of common mental disorders in women residing in informal settlement (slum) areas of Mumbai. METHODS: Experiences of violence were assessed through a detailed cross-sectional survey of 598 women, including questions about specific acts of emotional, economic, physical and sexual violence across different time points in the woman’s life and the main perpetrator of each act. Symptoms of common mental disorders were assessed using the 12-item General Health Questionnaire (GHQ-12). The GHQ-12 scores were divided into four groups and the relationship between experiences of each type of violence in the last 12 months and GHQ-12 score group was analyzed using ordinal logistic regression, adjusted for the woman’s age and clustering. RESULTS: 482 (81%) women consented to interview. On average, they were 28.5 years old, had completed 7 years of education and had been married 9 years. 88% were Muslim and 47% lived in joint and 53% in nuclear families. 44% of women had experienced at least one act of violence in their lifetime (33% emotional, 22% economic, 23% physical, 12% sexual). 7% had a high GHQ-12 score (6 or above). For violence experiences in the last 12 months, the odds of being in the highest GHQ-12 score group versus the lower groups combined were 13.1 for emotional violence, 6.5 for economic, 5.7 for physical and 6.3 for sexual (p<0.001 for all outcomes). DISCUSSION: The high level of violence reported across the lifetime could be due to the detailed assessment of violent acts at multiple time points and the inclusion of perpetrators within the family other than the husband. Each type of violence was associated with greater odds of a higher GHQ-12 score and therefore more symptoms of common mental disorders. Emotional violence was far more strongly associated with symptoms of common mental disorders than physical or sexual violence. However, it is not possible to attribute causal directionality to the association. Further work to investigate the relationship between differing severity of violence experiences and women’s mental health and the components of emotional violence that make it so strongly associated with symptoms of common mental disorders would be beneficial.

Keywords: common mental disorders, family violence, India, informal settlements, mental health, violence against women

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Authors: K. Parandhama Gowd

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The aim of this research paper is to conceptualize, discuss, analyze and propose alternate design methodologies for futuristic Black Box for flight safety. The proposal also includes global networking concepts for real time surveillance and monitoring of flight performance parameters including GPS parameters. It is expected that this proposal will serve as a failsafe real time diagnostic tool for accident investigation and location of debris in real time. In this paper, an attempt is made to improve the existing methods of flight data recording techniques and improve upon design considerations for futuristic FDR to overcome the trauma of not able to locate the block box. Since modern day communications and information technologies with large bandwidth are available coupled with faster computer processing techniques, the attempt made in this paper to develop a failsafe recording technique is feasible. Further data fusion/data warehousing technologies are available for exploitation.

Keywords: flight data recorder (FDR), black box, diagnostic tool, global networking, cockpit voice and data recorder (CVDR), air traffic control (ATC), air traffic, telemetry, tracking and control centers ATTTCC)

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Authors: Brigita Mieziene, Arunas Emeljanovas, Vida Cesnaitiene, Ingunn Fjortoft, Lise Kjonniksen

Abstract:

Background. Health-related physical fitness refers to the favorable health status, i.e. ability to perform daily activities with vigor, as well as capacities that are associated with a low risk for development of chronic diseases and premature death. However, in school-aged children it is constantly declining, while some aspects of fitness declined as much as 50 percent during the last two decades, which prognosticates increasingly earlier onset of health problems, decreasing the quality of life of the population and financial burden for the society. Therefore, the goal of the current study was to indicate nationally representative age- and gender-specific reference values of anthropometric measures, musculoskeletal, motor and cardiorespiratory fitness in Lithuanian primary school children from 6 to 10 years. Methods. The study included 3556 students in total, from 73 randomly selected schools. Ethics approval for research by the Kaunas Regional Ethics Committee (No. BE-2-42) was obtained. Physical fitness was measured by the 9-item test battery, developed by Fjørtoft and colleagues. Height and weight were measured and body mass index calculated. Smoothed centile charts were derived using the LMS method. Results. The numerical age- and gender-specific percentile values (3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentile) for anthropometric measures, musculoskeletal, motor and cardiorespiratory fitness were provided. The equivalent smoothed LMS curves were performed. The study indicated 12.5 percent of overweight and 5 percent of obese children in accordance with international gender and age specific norms of body mass index. This data could be used in clinical and educational settings in order to identify the level of individual physical fitness within its different components.

Keywords: fitness, overweight, primary school children, reference values, smoothed percentile curves

Procedia PDF Downloads 164

Authors: Ji-Sun Lee, Soong-Keun Hyun, Jin-Ho Kim

Abstract:

In this study, a glass fiber is fabricated using a continuous spinning process from alkali resistant (AR) glass with 4 wt% zirconia. In order to confirm the melting properties of the marble glass, the raw material is placed into a Pt crucible and melted at 1650 ℃ for 2 h, and then annealed. In order to confirm the transparency of the clear marble glass, the visible transmittance is measured, and the fiber spinning condition is investigated by using high temperature viscosity measurements. A change in the diameter is observed according to the winding speed in the range of 100–900 rpm; it is also verified as a function of the fiberizing temperature in the range of 1200–1260 ℃. The optimum winding speed and spinning temperature are 500 rpm and 1240 ℃, respectively. The properties of the prepared spinning fiber are confirmed using optical microscope, tensile strength, modulus, and alkali-resistant tests.

Keywords: glass composition, fiber diameter, continuous filament fiber, continuous spinning, physical properties

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Authors: Gerard Van Es

Abstract:

In this study, the use of a high resolution surface laser scanner to assess the micro texture of runway surfaces was investigated experimentally. Micro texture is one of the important surface components that helps to provide high braking friction between aircraft tires and a wet runway surface. Algorithms to derive different parameters that characterise micro texture was developed. Surface scans with a high resolution laser scanner were conducted on 40 different runway (like) surfaces. For each surface micro texture parameters were calculated from the laser scan data. These results were correlated with results obtained from a British pendulum tester that was used on the same surface. Results obtained with the British pendulum tester are generally considered to be indicative for the micro texture related friction characteristics. The results show that a meaningful correlation can be found between different parameters that characterise micro texture obtained with the laser scanner and the British pendulum tester results. Surface laser scanners are easier to operate and give more consistent results than a British pendulum tester. Therefore for airport operators surface laser scanners can be a useful tool to determine if their runway becomes slippery when wet due to a smooth micro texture.

Keywords: runway friction, micro texture, aircraft braking performance, slippery runways

Procedia PDF Downloads 129

Authors: Isik Z. Ulubas, Kaj Bjorkqvist

Abstract:

The relationships between perceived ethnic discrimination, peer aggression and school connectedness are being examined among 1,000 adolescents in Ostrobothnia, Finland with an online questionnaire. The study aims at investigating perceived ethnic discrimination in school environment by peers and teachers, and within society in general. Six types of aggressive behavior are measured: physical, verbal, indirect, and cyber aggression, in addition to both verbal and physical sexual harassment. High perceived ethnic discrimination is expected to be related with high aggression and low school connectedness. Adolescents who have special diet and clothing because of their cultural or religious background are expected to score higher on perceived ethnic discrimination and lower school connectedness. Adolescents who have lower domestic language skills (Finnish/Swedish) are expected to show lower school connectedness and higher perceived ethnic discrimination.

Keywords: adolescents, aggression, ethnic discrimination, school connectedness

Procedia PDF Downloads 223

Authors: Morteza Aien, Masoud Rashidinejad, Mahmud Fotuhi-Firuzabad

Abstract:

Power systems are innately uncertain systems. To face with such uncertain systems, robust uncertainty assessment tools are appealed. This paper inspects the uncertainty assessment formulation of the load flow (LF) problem considering different kinds of uncertainties, developed in its companion paper through some case studies. The proposed methodology is based on the evidence theory and joint propagation of possibilistic and probabilistic uncertainties. The load and wind power generation are considered as probabilistic uncertain variables and the electric vehicles (EVs) and gas turbine distributed generation (DG) units are considered as possibilistic uncertain variables. The cumulative distribution function (CDF) of the system output parameters obtained by the pure probabilistic method lies within the belief and plausibility functions obtained by the joint propagation approach. Furthermore, the imprecision in the DG parameters is explicitly reflected by the gap between the belief and plausibility functions. This gap, due to the epistemic uncertainty on the DG resources parameters grows as the penetration level increases.

Keywords: electric vehicles, joint possibilistic- probabilistic uncertainty modeling, uncertain load flow, wind turbine generator

Procedia PDF Downloads 432

Authors: Abdel Moktader A. El Sayed, Nahla A. El Sayed

Abstract:

Fifty-one sandstone core samples were obtained from the wadi Saal area. They belong to the Pre-Cenomanian age. These samples were subjected to various laboratory measurements such as density, porosity, permeability, electrical resistivity, grain size analysis and ultrasonic wave velocity. The parameters describing reservoir properties are outlined. The packing index, reservoir quality index, flow zone indicator and pore throat radius (R35 and R36) were calculated. The obtained interrelationships among these parameters allow improving petrophysical knowledge about the Pre-Cenomanian reservoir information. The obtained rock physics models could be employed with some precautions to the subsurface existences of the Pre-Cenomanian sandstone reservoirs, especially in the surrounding areas.

Keywords: resevoir sandstone, Egypt, Sinai, permeability

Procedia PDF Downloads 102