Search results for: Ergonomic exposure

Authors: C. M. M. Paschoal, D. do N. Souza, L. A. P. Santos

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In this study three commercial semiconductor devices were characterized in the laboratory for computed tomography dosimetry: one photodiode and two phototransistors. It was evaluated four responses to the irradiation: dose linearity, energy dependence, angular dependence and loss of sensitivity after X ray exposure. The results showed that the three devices have proportional response with the air kerma; the energy dependence displayed for each device suggests that some calibration factors would be applied for each one; the angular dependence showed a similar pattern among the three electronic components. In respect to the fourth parameter analyzed, one phototransistor has the highest sensitivity however it also showed the greatest loss of sensitivity with the accumulated dose. The photodiode was the device with the smaller sensitivity to radiation, on the other hand, the loss of sensitivity after irradiation is negligible. Since high accuracy is a desired feature for a dosimeter, the photodiode can be the most suitable of the three devices for dosimetry in tomography. The phototransistors can also be used for CT dosimetry, however it would be necessary a correction factor due to loss of sensitivity with accumulated dose.

Keywords: Dosimetry, computed tomography, phototransistor, photodiode

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Authors: Mohammad Mirjalili, Hamid Akbarpour

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In this work, a bleached well cotton sample was dyed with reactive yellow105 dye and subsequently, the dyed sample was exposed to the plasma condition containing Nitrogen gas at 1 and 5 minutes of plasma exposure time, respectively. The effect of plasma on surface morphology fabric was studied by Scanning Electronic Microscope (SEM). CIELab, K/S, and %R of samples (treated and untreated samples) were measured by a reflective spectrophotometer, and consequently, the experiments show that the sample dyed with Reactive yellow 105 after being washed, with the increase in the operation time of plasma, its dye fastness decreases. In addition, the increase in plasma operation time at constant pressure would increase the destructing effect on the surface morphology of samples dyed with reactive yellow105.

Keywords: Cotton fabric, cold nitrogen plasma, reflective spectrophotometer, electronic scanning microscope (SEM), reactive yellow105 dye.

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Authors: Mariya P. Aleksandrova, Ivelina N. Cholakova, Georgy K. Bodurov, Georgy D. Kolev, Georgy H. Dobrikov

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Indium-tin oxide films are deposited by low plasma temperature RF sputtering on highly flexible modification of glycol polyethyleneterephtalate substrates. The produced layers are characterized with transparency over 82 % and sheet resistance of 86.9 Ω/square. The film’s conductivity was further improved by additional UV illumination from light source (365 nm), having power of 250 W. The influence of the UV exposure dose on the structural and electro-optical properties of ITO was investigated. It was established that the optimum time of illumination is 10 minutes and further UV treatment leads to polymer substrates degradation. Structural and bonds type analysis show that at longer treatment carbon atoms release and diffuse into ITO films, which worsen their electrical behavior. For the optimum UV dose the minimum sheet resistance was measured to be 19.2 Ω/square, and the maximum transparency remained almost unchanged – above 82 %.

Keywords: Flexible displays, indium tin oxide, RF sputtering, UV treatment

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Authors: Jungho Moon, Tae Kwon Ha

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Effect of alloying on the microstructure and mechanical properties of heat-resisting duplex stainless steel (DSS) for Mg production was investigated in this study. 25Cr-8Ni based DSS’s were cast into rectangular ingots of which the dimension was 350×350×100 mm3 . Nitrogen and Yttrium were added in the range within 0.3 in weight percent. Phase equilibrium was calculated using the FactSage®, thermodynamic software. Hot exposure, high temperature tensile and compression tests were conducted on the ingots at 1230oC, which is operation temperature employed for Mg production by Silico-thermic reduction. The steel with N and Y showed much higher strength than 310S alloy in both tensile and compression tests. By thermal exposition at 1230oC for 200 hrs, hardness of DSS containing N and Y was found to increase. Hot workability of the heat-resisting DSS was evaluated by employing hot rolling at 1230 oC. Hot shortness was observed in the ingot with N and found to disappear after addition of Y.

Keywords: Duplex Stainless Steel, alloying elements, eutectic carbides, microstructure, aging treatment.

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Authors: Aitor Barbero-López, Soumaya Chibily, Gerhard Scheepers, Thomas Grahn, Martti Venäläinen, Antti Haapala

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Wood decay is addressed continuously within the wood industry through use and development of wood preservatives. The increasing awareness on the negative effects of many chemicals towards the environment is causing political restrictions in their use and creating more urgent need for research on green alternatives. This paper discusses some of the possible natural extracts for wood preserving applications and compares the analytical methods available for testing their behavior and efficiency against decay fungi. The results indicate that natural extracts have interesting chemical constituents that delay fungal growth but vary in efficiency depending on the chemical concentration and substrate used. Results also suggest that presence and redistribution of preservatives in wood during exposure trials can be assessed by spectral imaging methods although standardized methods are not available. This study concludes that, in addition to the many standard methods available, there is a need to develop new faster methods for screening potential preservative formulation while maintaining the comparability and relevance of results.

Keywords: Analytics, methods, preservatives, wood decay.

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Authors: Minami Ito, Akihiro Iijima

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On March 11, 2011, the Great East Japan Earthquake occurred off the coast of Sanriku, Japan. It is important to build a sustainable society through the reconstruction process rather than simply restoring the infrastructure. To compare the goals of reconstruction plans of quake-stricken municipalities, Japanese language morphological analysis was performed by using text mining techniques. Frequently-used nouns were sorted into four main categories of “life”, “disaster prevention”, “economy”, and “harmony with environment”. Because Soma City is affected by nuclear accident, sentences tagged to “harmony with environment” tended to be frequent compared to the other municipalities. Results from cluster analysis and principle component analysis clearly indicated that the local government reinforces the efforts to reduce risks from radiation exposure as a top priority.

Keywords: Eco-friendly reconstruction, harmony with environment, decontamination, nuclear disaster.

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Authors: Travis J. Meyer, Jasodra Ramlall, Phyo Thu, Nidhi Gadura

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For centuries humans have used the antimicrobial properties of copper to their advantage. Yet, after all these years the underlying mechanisms of copper mediated cell death in various microbes remain unclear. We had explored the hypothesis that copper mediated increased levels of lipid peroxidation in the membrane fatty acids is responsible for increased killing in Escherichia coli. In this study we show that in both gram positive (Staphylococcus aureus) and gram negative (Pseudomonas aeruginosa) bacteria there is a strong correlation between copper mediated cell death and increased levels of lipid peroxidation. Interestingly, the non-spore forming gram positive bacteria as well as gram negative bacteria show similar patterns of cell death, increased levels of lipid peroxidation, as well as genomic DNA degradation, however there is some difference in loss in membrane integrity upon exposure to copper alloy surface.

Keywords: Antimicrobial, copper, gram positive, gram negative.

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Authors: Seong Do Kim, Woo Young Jung

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Recently, damages due to typhoons and strong wind are on the rise. Considering this issue, we evaluated the performance of soundproofing walls based on the strong wind fragility by means of numerical analysis. Among the components of the soundproof wall, aluminum frame was the most vulnerable member, thus we have considered different section of aluminum frame in the determination of wind fragility. Wind load was randomly generated using Monte Carlo Simulation method. Moreover, limit state was based on the test standard of road construction soundproofing wall. In this study, the strong wind fragility was determined by considering the influence factors of wind exposure category, soundproof wall’s installation position, and shape of aluminum frame section. Results of this study could be used to determine the section shape of the frame that has high resistance to the wind during construction of the soundproofing wall.

Keywords: Aluminum frame soundproofing wall, Monte Carlo Simulation, numerical simulation, wind fragility.

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Authors: E. Binaeian, A.M. Rashidi, H. Attar

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A comparative evaluation of acute toxicity of synthesized nano silvers using two different procedures (biological and chemical reduction methods) and silver ions on bacteria Vibrio fischeri was investigated. The bacterial light inhibition test as a toxicological endpoint was used by applying of a homemade luminometer. To compare the toxicity effects as a quantitative parameter, a nominal effective concentrations (EC) of chemicals and a susceptibility constant (Z-value) of bacteria, after 5 min and 30 min exposure times, were calculated. After 5 and 30 min contact times, the EC50 values of two silver nanoparticles and the EC20 values were about similar. It demonstrates that toxicity of silvers was independent of their procedure. The EC values of nanoparticles were larger than those of the silver ions. The susceptibilities(Z- Values) of V.fischeri (L/mg) to the silver ions were greater than those of the nano silvers. According to the EC and Z values, the toxicity of silvers decreased in the following order: Silver ions >> silver nanoparticles from chemical reduction method ~ silver nanoparticles from biological method.

Keywords: Bioluminescence, Luminometer, silver nano particles, Toxicity, Vibrio fischeri

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Authors: Nomusa Dlodlo, Ronald Noel Beyers

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This paper reports on an effort to address the issue of inequality in girls- and women-s access to science, engineering and technology (SET) education and careers through raising awareness on SET among secondary school girls in South Africa. Girls participated in hands-on high-tech rapid prototyping environment of a fabrication laboratory that was aimed at stimulating creativity and innovation as part of a Fab Kids initiative. The Fab Kids intervention is about creating a SET pipeline as part of the Young Engineers and Scientists of Africa Initiative.The methodology was based on a real world situation and a hands-on approach. In the process, participants acquired a number of skills including computer-aided design, research skills, communication skills, teamwork skills, technical drawing skills, writing skills and problem-solving skills. Exposure to technology enhanced the girls- confidence in being able to handle technology-related tasks.

Keywords: Girls, design engineering, gender, science, women.

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Authors: Nashwa Kamel Ibrahim

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Kombucha Tea Ferment (KT), was given to male albino rats, (1ml/Kg of body weight), via gavages, during 2 weeks before intraperitoneal administration of 3.5 mg/Kg body weight CdCl2 and/or whole body γ-irradiation with 4Gy, and during 4 weeks after each treatment. Hepatic and nephritic pathological changes included significant increases of serum alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) activities, and creatinine and urea contents with significant decrease in serum total antioxidant capacity (TAC). Increase in oxidative stress markers in liver and kidney tissues expressed by significant increase in malondialdehyde (MDA) and nitric oxide (NO) contents associated to significant depletion in superoxide dismutase (SOD) and catalase (CAT) activities, and reduced glutathione (GSH) content were recorded. KT administration results in recovery of all the pathological changes. It could be concluded that KT might protect liver and kidney from oxidative damage induced by exposure to cadmium and/ or γ-irradiation.

Keywords: Cadmium, Kombucha, radiation, rats

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Authors: Fareeha A., Irfan Z Qureshi

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Thrombosis can be life threatening, necessitating therefore its instant treatment. Hydergine, a nootropic agent is used as a cognition enhancer in stroke patients but relatively little is known about its anti-thrombolytic effect. To investigate this aspect, in vivo and ex vivo experiments were designed and conducted. Three groups of rats were injected 1.5mg, 3.0mg and 4.5mg hydergine intraperitonealy with and without prior exposure to fresh plasma. Positive and negative controls were run in parallel. Animals were sacrificed after 1.5hrs and BT, CT, PT, INR, APTT, plasma calcium levels were estimated. For ex vivo analyses, each 1ml blood aspirated was exposed to 0.1mg, 0.2mg, 0.3mg dose of hydergine with parallel controls. Parameters analyzed were as above. Statistical analysis was through one-way ANOVA. Dunken-s and Tukey-s tests provided intra-group variance. BT, CT, PT, INR and APTT increased while calcium levels dropped significantly (P<0.05). Ex vivo, CT, PT and APTT were elevated while plasma calcium levels lowered significantly (P<0.05). Our study suggests that hydergine may act as a thrombolytic agent but warrants further studies to elucidate this role of ergot mesylates.

Keywords: Hydergine, Coagulation assays, plasma calcium, ergot mesylates, thrombosis.

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Authors: K. Mahmoud, T. Shalahmetova, Sh. Deraz

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The objective of the present study was to examine the dose-response relationships between antioxidant parameters and liver contaminant levels of Kazakhstan light crude oil (KLCO) in albino rats. The animals were repeatedly exposed, by intraperitoneal injection, to low dosages (0.5–1.5 ml/kg) of KLCO. Rats exposed to these doses levels did not show any apparent symptoms of intoxication. Serum aminotransferases increased significantly (p<0.05) while after 8-d recovered to control level. hepatic superoxide dismutase (SOD) activity significantly increased after 1 and 3-d except with 0.5 ml while with increased exposure time it deceased insignificantly after 5-d and significantly after 8-d. Dose and time-dependent increases were observed in the levels of hepatic glutathione-S-transeferase (GST) and conjugated diene (CD) while malondialdehyde (MDA) was evolved after 8 with the dose of 1.5 ml. the data obtained indicate impaired liver function in the rats intoxicated with KLCO as manifested by elevated liver enzymes.

Keywords: Crude oil; superoxide dismutase, glutathione-Stranseferase, malondialdehyde, conjugated diene, aminotransferases.

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Authors: Y. Hong, H. Y. Hu, A. Sakoda, M. Sagehashi

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In this study, inhibition of Microcystis aeruginosa by antialgal alleochemical gramine, was studied by analyzing algal metabolic activity (represented by esterase and total dehydrogenase activities) and cell ultrastructure (showing morphological and ultrastructure alterations using transmission electron microscopy and DNA ladder analysis). After gramine exposure, esterase and total dehydrogenase activities were increased firstly but decreased later. In contrast with the controls, the cells exposed to gramine showed apparent ultrastructure alterations with thylakoids in breakage, phycobilins in decrease, lipid and cyanophycin granules abundant firstly but dissolved afterwards, DNA in fragementation. The occurrence of increase of metabolic activity and specific granules reflected that the resistance of cellular response to gramine was initiated. DNA fragementation associated with the increase of metabolic activity and specific granules hinted that gramine caused M. aeruginosa cells to initiate some morphotype of programmed cell death.

Keywords: Allelochemical, gramine, metabolic activity, Microcystis aeruginosa, ultrastructure.

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Authors: Mohammed Abed, Rita Nemes, Salem Nehme

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The present study experimentally investigated the impact of incorporating unprocessed waste fly ash (UWFA) on the residual mechanical properties of self-compacting concrete (SCC) after exposure to elevated temperature. Three mixtures of SCC have been produced by replacing the cement mass by 0%, 15% and 30% of UWFA. Generally, the fire resistance of SCC has been enhanced by replacing the cement up to 15% of UWFA, especially in case of residual modulus of elasticity which considers more sensitive than other mechanical properties at elevated temperature. However, a strong linear relationship has been observed between the residual flexural strength and modulus of elasticity, where both of them affected significantly by the cracks appearance and propagation as a result of elevated temperature. Sustainable products could be produced by incorporating unprocessed waste powder materials in the production of concrete, where the waste materials, CO₂ emissions, and the energy needed for processing are reduced.

Keywords: Self-compacting high-performance concrete, unprocessed waste fly ash, fire resistance, residual modulus of elasticity.

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Authors: H. Bouaziz, N. Soudania, M. Essafia, I. Ben Amara, A. Hakim, K. Jamoussi, Km. Zeghal, N. Zeghal

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In this investigation, we have evaluated the effects of arsenic trioxide on hepatic function in pregnant and lactating Swiss albino mice and their suckling pups. Experiments were carried out on female mice given 175 ppm As2O3 in their drinking water from the 14th day of pregnancy until day 14 after delivery. Our results showed a significant decrease in plasma levels of total protein and albumin, cholesterol and triglyceride in As2O3 treated mice and their pups. The hyperbilirubinemia and the increased plasma total alkaline phosphatase activity suggested the presence of cholestasis. Transaminase activities as well as lactate deshydrogenase activity in plasma, known as biomarkers of hepatocellular injury, were elevated indicating hepatic cells’ damage after treatment with As2O3. Exposure to arsenic led to an increase of liver thiobarbituric acid reactive substances level along with a concomitant decrease in the activities of superoxide dismutase, catalase and glutathione peroxidase and in glutathione.

Keywords: Antioxidant status, arsenic trioxide, hepatotoxicity, mice, oxidative stress.

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Authors: Fl. Loury, P. Sablonière, C. Lamoureux, G. Magnier, Th. Gutierrez

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A method is proposed to extract faithful representative patterns from data set of observations when they are suffering from non-negligible fluctuations. Supposing time interval between measurements to be extremely small compared to observation time, it consists in defining first a subset of intermediate time intervals characterizing coherent behavior. Data projection on these intervals gives a set of curves out of which an ideally “perfect” one is constructed by taking the sup limit of them. Then comparison with average real curve in corresponding interval gives an efficiency parameter expressing the degradation consecutive to fluctuation effect. The method is applied to sunlight data collected in a specific place, where ideal sunlight is the one resulting from direct exposure at location latitude over the year, and efficiency is resulting from action of meteorological parameters, mainly cloudiness, at different periods of the year. The extracted information already gives interesting element of decision, before being used for analysis of plant control.

Keywords: Base Input Reconstruction, Data Mining, Efficiency Factor, Information Pattern Operator.

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Authors: WooYoung Jung, Buntheng Chhorn, Min-Gi Kim

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Recently, damage to domestic facilities by strong winds and typhoons are growing. Therefore, this study focused on sign structure among various vulnerable facilities. The evaluation of the wind fragility was carried out considering the destruction of the anchor, which is one of the various failure modes of the sign structure. The performance evaluation of the anchor was carried out to derive the wind fragility. Two parameters were set and four anchor types were selected to perform the pull-out and shear tests. The resistance capacity was estimated based on the experimental results. Wind loads were estimated using Monte Carlo simulation method. Based on these results, we derived the wind fragility according to anchor type and wind exposure category. Finally, the evaluation of the wind fragility was performed according to the experimental parameters such as anchor length and anchor diameter. This study shows that the depth of anchor was more significant for the safety of structure compare to diameter of anchor.

Keywords: Sign structure, wind fragility, set anchor, pull-out test, shear test, Monte Carlo simulation.

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Authors: A. Alhazza, B. Alnaser

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Orthodontic restorative materials are widely used for the direct restoration of teeth or for cosmetic dentistry purposes. These materials have helped to solve many dental problems, providing healthy and beautiful smiles for many patients. In this study, we aimed to investigate whether the pH value has an effect on the surface structure of a nanohybrid composite material. Five different types of highly consumed beverages were selected to examine their effect on the surface structure of the nanohybrid composite material. The beverages had different pH values in the range of 3–6, i.e., they were all acidic. The material was investigated under the hardest conditions of surface exposure to the drinks by immersing the material for a long period. The specimens were examined using scanning electron microscopy (SEM) at different magnifications to investigate the effect of these beverages on the morphology of the nanohybrid composite material discs. All specimens showed an effect including pores, cracks, protrusions, and surface roughness as a result of the beverages. The degree of effect differed from one experimental group to another, but there was no relationship between the pH (acidity) value and the degree of effect on the surface structure of the specimens.

Keywords: Acidity, beverage, SEM, dentistry.

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Authors: Vijay Pal Singh, Yogesh Chandra Kotiyal

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Structures are a combination of various load carrying members which transfer the loads to the foundation from the superstructure safely. At the design stage, the loading of the structure is defined and appropriate material choices are made based upon their properties, mainly related to strength. The strength of materials kept on reducing with time because of many factors like environmental exposure and deformation caused by unpredictable external loads. Hence, to predict the strength of materials used in structures, various techniques are used. Among these techniques, Non-destructive techniques (NDT) are the one that can be used to predict the strength without damaging the structure. In the present study, the compressive strength of concrete has been predicted using Artificial Neural Network (ANN). The predicted strength was compared with the experimentally obtained actual compressive strength of concrete and equations were developed for different models. A good co-relation has been obtained between the predicted strength by these models and experimental values. Further, the co-relation has been developed using two NDT techniques for prediction of strength by regression analysis. It was found that the percentage error has been reduced between the predicted strength by using combined techniques in place of single techniques.

Keywords: Rebound, ultra-sonic pulse, penetration, ANN, NDT, regression.

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Authors: Abdullah Almusharraf, Andrew Whyte

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The sub-task pattern in terms of deviations and defects should be identified and understood in order to improve the quality of practices in construction projects. Therefore, sub-task susceptibility to exposure to deviations and defects has been evaluated and classified via six classifications proposed in this study. Thirty-four case studies of specific sub-tasks (from compression members in constructed concrete structures) were collected from seven construction projects in order to examine the study’s proposed classifications. The study revealed that the sub-task has a high sensitivity to deviation, where 91% of the cases were recorded as deviations; however, only 19% of cases were recorded as defects. Other findings were that the actual work during the execution process is a high source of deviation for this sub-task (74%), while only 26% of the source of deviation was due to both design documentation and the actual work. These findings significantly imply that the study’s proposed classifications could be used to determine the pattern of each sub-task and develop proactive actions to overcome issues of sub-task deviations and defects.

Keywords: Sub-tasks, deviations, defects, quality, construction projects.

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Authors: Ming-Lun Chiang, Hsi-Chia Chen, Chieh Wu, Yu-Ting Tseng, Ming-Ju Chen

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In this study, three strains of Vibrio parahaemolyticus (690, BCRC 13023 and BCRC 13025) were subjected to acid adaptation at pH 5.5 for 90 min. The survival of acid-adapted and non-adapted V. parahaemolyticus strains under simulated gastric condition and their protein expression profiles were investigated. Results showed that acid adaptation increased the survival of the test V. parahaemolyticus strains after exposure to simulated gastric juice (pH 3). Additionally, acid adaptation also affected the protein expression in these V. parahaemolyticus strains. Nine proteins, identified as atpA, atpB, DnaK, GroEL, OmpU, enolase, fructose-bisphosphate aldolase, phosphoglycerate kinase and triosephosphate isomerase, were induced by acid adaptation in two or three of the test strains. These acid-adaptive proteins may play important regulatory roles in the acid tolerance response (ATR) of V. parahaemolyticus.

Keywords: Acid adaptation, protein expression, simulated gastric juice, Vibrio parahaemolyticus

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Authors: Salah I. Al-Mously, Marai M. Abousetta

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This paper investigates the impact of the hand-hold positions on both antenna performance and the specific absorption rate (SAR) induced in the user-s head. A cellular handset with external antenna operating at GSM-900 frequency is modeled and simulated using a finite difference time-domain (FDTD)-based platform SEMCAD-X. A specific anthropomorphic mannequin (SAM) is adopted to simulate the user-s head, whereas a semirealistic CAD-model of three-tissues is designed to simulate the user-s hand. The results show that in case of the handset in hand close to head at different positions; the antenna total efficiency gets reduced to (14.5% - 5.9%) at cheek-position and to (27.5% to 11.8%) at tilt-position. The peak averaged SAR1g values in head close to handset without hand, are 4.67 W/Kg and 2.66 W/Kg at cheek and tilt-position, respectively. Due to the presence of hand, the SAR1g in head gets reduced to (3.67-3.31 W/Kg) at cheek-position and to (1.84-1.64 W/Kg) at tilt-position, depending on the hand-hold position.

Keywords: FDTD, phantom, specific absorption rate (SAR), cellular handset exposure.

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Authors: Deepak Mohan, Sushma Sharma

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Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are a group of widely used drugs for the treatment of rheumatoid diseases and to relieve pain and inflammation due to their analgesic anti-pyretic and anti-inflammatory properties. The therapeutic and many of the toxic effects of NSAIDs result from reversible inhibition of enzymes in the cyclooxygenase (COX) group. In the present investigation the effect of the drug on the concentration of lipids, and on the activity of the enzymes i.e. acid and alkaline phosphatase, GOT, GPT and lipid peroxidase were studied. There was a significant enhancement in the activities of both acid and alkaline phosphatase after 21 days of treatment. Proportionate increase in the MDA contents was observed after different days of diclofenac treatment. Cellular damage in the liver resulted in decrease in the activity of both GOT (Glutamate oxaloacetate transaminase) and GPT (Glutamate pyruvate transaminase) in both low and high dose groups. Significant decrease in the liver contents was also observed in both dose groups.

Keywords: Anti-inflammatory, cyclooxygenase, glutamate oxaloacetate transaminase, malondialdehyde.

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Authors: Isa Nakhai Kamal Abadi, Esmaeel Saberi, Ehsan Mirjafari

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While financial institutions have faced difficulties over the years for a multitude of reasons, the major cause of serious banking problems continues to be directly related to lax credit standards for borrowers and counterparties, poor portfolio risk management, or a lack of attention to changes in economic or other circumstances that can lead to a deterioration in the credit standing of a bank's counterparties. Credit risk is most simply defined as the potential that a bank borrower or counterparty will fail to meet its obligations in accordance with agreed terms. The goal of credit risk management is to maximize a bank's risk-adjusted rate of return by maintaining credit risk exposure within acceptable parameters. Banks need to manage the credit risk inherent in the entire portfolio as well as the risk in individual credits or transactions. Banks should also consider the relationships between credit risk and other risks. The effective management of credit risk is a critical component of a comprehensive approach to risk management and essential to the long-term success of any banking organization. In this research we also study the relationship between credit risk indices and borrower-s timely payback in Karafarin bank.

Keywords: Financial Ratios; Spearman Test; Bank OperationsRisk

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Authors: M. Al Nur, M. S. Kaiser

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Corrosion behaviour of hypereutectic Al-19Si automotive alloy in different pH=1, 3, 5, 7, 9, 11, and 13 environments was carried out using conventional gravimetric measurements and was complemented by resistivity, optical micrograph, scanning electron microscopy (SEM) and X-ray analyzer (EDX) investigations. Gravimetric analysis confirmed that the highest corrosion rate is shown at pH 13 followed by pH 1. Minimum corrosion occurs in the pH range of 3.0 to 11 due to establishment of passive layer on the surface. The highest corrosion rate at pH 13 is due to the presence of sodium hydroxide in the solution which dissolves the surface oxide film at a steady rate. At pH 1, it can be attributed that the presence of aggressive chloride ions serves to pick up the damage of the passive films at localized regions. With varying exposure periods by both, the environment complies with the normal corrosion rate profile that is an initial steep rise followed by a nearly constant value of corrosion rate. Resistivity increases in case of pH 1 solution for the higher pit formation and decreases at pH 13 due to formation of thin film. The SEM image of corroded samples immersed in pH 1 solution clearly shows pores on the surface and in pH 13 solution, and the corrosion layer seems more compact and homogenous and not porous.

Keywords: Al-Si alloy, corrosion, pH, resistivity, SEM.

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Authors: T. Dubayova

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Slovak, as well as foreign authors, believe that the influence of non-cognitive factors on a student's academic success or failure is unquestionable. The aim of this paper is to establish a link between the mental vulnerability and coping strategies used by 4^th grade elementary school students in dealing with stressful situations and their academic performance, which was used as a simple quantitative indicator of academic success. The research sample consists of 320 students representing the standard population and 60 students with special education needs (SEN), who were assessed by the Strengths and Difficulties Questionnaire (SDQ) by their teachers and the Children’s Coping Strategies Checklist (CCSC-R1) filled in by themselves. Students with SEN recorded an extraordinarily high frequency of mental vulnerability (34.5 %) than students representing the standard population (7 %). The poorest academic performance of students with SEN was associated with the avoidance behavior displayed during stressful situations. Students of the standard population did not demonstrate this association. Students with SEN are more likely to display mental health problems than students of the standard population. This may be caused by the accumulation of and frequent exposure to situations that they perceive as stressful.

Keywords: Coping, mental vulnerability, students with special education needs, academic performance, academic success.

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Authors: Wen W. Zhang, Qian Chen

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Electron multiplying charge coupled devices (EMCCDs) have revolutionized the world of low light imaging by introducing on-chip multiplication gain based on the impact ionization effect in the silicon. They combine the sub-electron readout noise with high frame rates. Signal-to-noise Ratio (SNR) is an important performance parameter for low-light-level imaging systems. This work investigates the SNR performance of an EMCCD operated in Non-inverted Mode (NIMO) and Inverted Mode (IMO). The theory of noise characteristics and operation modes is presented. The results show that the SNR of is determined by dark current and clock induced charge at high gain level. The optimum SNR performance is provided by an EMCCD operated in NIMO in short exposure and strong cooling applications. In contrast, an IMO EMCCD is preferable.

Keywords: electron multiplying charge coupled devices, noise characteristics, operation modes, signal-to-noise ratioperformance

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Authors: Sh. Ranjbar-Bahadori, N. Farhadifar, L. Mohammadyar

Abstract:

Plant preparations from thyme and garlic have been shown to be effective acaricides against the poultry red mite, Dermanyssus gallinae. In a layer house with a history of D. gallinae problem, mites were detected in the monitoring traps for the first time and number of them was counted. Then, some rows of layer house was sprayed twice using a concentration of 0.21 mg/cm² thyme essential oil and 0.07 mg/cm² garlic juice and a similar row was used as an untreated control group. Red mite traps made of cardboard were used to assess the mite density during days 1 and 7 after treatment and always removed after 24 h. the collected mites were counted and the efficacy against all mite stages (larvae, nymphs and adults) was calculated. Results showed that on day 1 and 7 after the administration of garlic extract efficacy rate was 92.05% and 74.62%, respectively. Moreover, efficacy rate on day 1 and 7 was 89.4% and 95.37% when treatment was done with thyme essential oil. It is concluded that using garlic juice to control of D. gallinae is more effective on short time. But thyme essential oil has a long time effect in compare to garlic preparation.

Keywords: Dermanyssus gallinae, Essential oil, Garlic, Thyme, Efficacy.

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Authors: Pratoom Rekklang

Abstract:

The purposes of this study are to study political information exposure, politicians- perceptions, political attitudes and political participations among people in Bangkok Metropolitan Area. The sample consisted of 420 which were selected by using accidental sampling method. Questionnaires were administered to all of the respondents to obtain the data for this research. T-test, one-way ANOVA and Pearson-s correlation coefficient were used to analyze the data. The findings are as follows: The difference in gender, education, income and occupation has significantly effect upon political information exposures. The difference in age, income has significantly effect upon politicians- perceptions. The difference in income has significantly effect upon political attitudes. The difference in gender, income and occupation has significantly effect upon political participations. There were a significantly relations between political information exposures, political attitudes, political participations and between politicians- perceptions, political attitudes and political participations.

Keywords: Political Information Exposures, Politicians' Perceptions, Political Attitudes, Political Participations.

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