Search results for: solid stress

Authors: Leila Kharrat, Younes Boujelbene

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In recent decades, solid waste management (SWM) has become a global concern because rapid population growth and overexploitation of non-renewable resources have generated enormous amounts of waste far exceeding carrying capacity; too, it poses serious threats to the environment and health. However, it is still difficult to combat the growing amount of solid waste before assessing the condition of people. Therefore, this study was conducted to assess the knowledge, attitudes, perception, and practices on the separation of solid waste in Sfax City. Nowadays, GDS is essential for sustainable development, hence the need for intensive research. Respondents from seven different districts in the city of Sfax were analyzed through a questionnaire survey with 342 households. This paper presents a qualitative exploratory study on the behavior of the citizens in the field of waste separation. The objective knows the antecedents of waste separation and the representation that individuals have about sorting waste on a specific territory which presents some characteristics regarding waste management in Sfax city. Source separation is not widely practiced and people usually sweep their places throwing waste components into the streets or neighboring plots. The results also indicate that participation in solid waste separation activities depends on the level of awareness of separating activities in the area, household income and educational level. It is, therefore, argued that increasing quality of municipal service is the best means of promoting positive attitudes to solid waste separation activities. One of the effective strategies identified by households that can be initiated by policymakers to increase the rate of participation in separation activities and eventually encourage them to participate in recycling activities is to provide a financial incentive in all residential areas in Sfax city.

Keywords: solid waste management, waste separation, public policy, econometric modelling

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Authors: Lee Seungheon, Kim Ba-Ro

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In this study, the anti-stress effects of the ethanolic extract of Hydrangeae Dulcis Folium (EHDF) were investigated. To determine the effects of EHDF on physical stress, changes in the whole-body cortisol level and behaviour were monitored in zebrafish. To induce physical stress, we used the net handling stress (NHS). Fish were treated with EHDF for 6 min before they were exposed to stress, and the fish were either evaluated via behavioural tests, including a novel tank test and an open field test or sacrificed to collect body fluid from the whole body. The results indicate that increased anxiety-like behaviours in the novel tank test and open field test under stress were recovered by treatment with EHDF at 5, 10 and 20 mg/L (P < 0.05). Moreover, compared with the normal group, which was not treated with NHS, the whole-body cortisol level was significantly increased by treatment with NHS in the control group. Compared with the control group, pre-treatment with EHDF at concentrations of 5, 10 and 20 mg/L for 6 min significantly prevented the increase in the whole-body cortisol level induced by NHS (P < 0.05). In addition, adrenocorticotropin hormone (ACTH) challenge studies showed that EHDF completely blocked the effects of ACTH (0.2 IU/g, IP) on cortisol secretion. These results suggest that EHDF may be a good anti-stress candidate and that its mechanism of action may be related to its positive effects on cortisol release.

Keywords: net handling stress, zebrafish, hydrangeae dulcis folium, whole-body cortisol, novel tank test, open field test

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Authors: I. Made Gatot Karohika, Shigeyuki Haruyama, Ken Kaminishi, Oke Oktavianty, Didik Nurhadiyanto

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Contact width and contact stress are important parameters related to the leakage behavior of corrugated metal gasket. In this study, contact width and contact stress of three-layer corrugated metal gasket are investigated due to the modulus of elasticity and thickness of surface layer for 2 type gasket (0-MPa and 400-MPa mode). A finite element method was employed to develop simulation solution to analysis the effect of each parameter. The result indicated that lowering the modulus of elasticity ratio of surface layer will result in better contact width but the average contact stresses are smaller. When the modulus of elasticity ratio is held constant with thickness ratio increase, its contact width has an increscent trend otherwise the average contact stress has decreased trend.

Keywords: contact width, contact stress, layer, metal gasket, corrugated, simulation

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Authors: Leydi Noemi Peraza Gómez, Jose Álvarez Nemegyei, Damaris Francis Estrella Castillo

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In order to have an epidemiological tool to detect biomechanical stress (ERGO-Mex), which impose physical labor or recreational activities, a questionnaire is constructed in Spanish, validated and culturally adapted to the Mayan indigenous population of Yucatan. Through the seven steps proposed by Guillemin and Beaton the procedure was: initial translation, synthesis of the translations, feed back of the translation. After that review by a committee of experts, pre-test of the preliminary version, and presentation of the results to the committee of experts and members of the community. Finally the evaluation of its internal validity (Cronbach's α coefficient) and external (intraclass correlation coefficient). The results for the validation in Spanish indicated that 45% of the participants have biomechanical stress. The ERGO-Mex correlation was 0.69 (p <0.0001). Subjects with high biomechanical stress had a higher score than subjects with low biomechanical stress (17.4 ± 8.9 vs.9.8 ± 2.8, p = 0.003). The Cronbach's α coefficient was 0.92; and for validation in Cronbach's α maya it was 0.82 and CCI = 0.70 (95% CI: 0.58-0.79; p˂0.0001); ERGO-Mex is suitable for performing early detection of musculoskeletal diseases and helping to prevent disability.

Keywords: biomechanical stress, disability, musculoskeletal disorders, prevention

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Authors: Mebrahtu Haile

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Fuels obtained from renewable resources have garnered significant enthusiasm in recent decades due to concerns about fossil fuel depletion and climate change. This study aimed to investigate the potential of Prosopis juliflora pods mash for bio-ethanol production and its hydrolysis solid waste for solid fuel. Various parameters, such as acid concentration, hydrolysis times, fermentation times, fermentation temperature, and pH, were evaluated for their impact on bio-ethanol production using Saccharomyces cerevisiae yeast. The results showed that increasing acid concentration (up to 1 molar H₂SO₄) led to an increase in sugar content, reaching a maximum of 96.13%v/v. Optimal conditions for bio-ethanol production were found at 1 molar H₂SO₄ concentration (4.2%v/v), 48 hours fermentation time (5.1%v/v), 20 minutes hydrolysis time (5.57%v/v), 30°C fermentation temperature (5.57%v/v), and pH 5 (6.01%v/v), resulting in a maximum bio-ethanol yield of 6.01%v/v. The solid waste remaining after bio-ethanol production exhibited potential for use as a solid fuel, with a calorific value of 18.22 MJ/kg. These findings demonstrate the promising potential of Prosopis juliflora pods mash for bio-ethanol production and suggest a viable solution for addressing disposal challenges associated with solid waste, contributing to the exploration of renewable fuel sources in the face of fossil fuel depletion and climate change.

Keywords: prosopis juliflora, pods mash, invasive species, bio-ethanol, fermentation, Saccharomyces cerevisiae, solid fuel

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Authors: L. Torchane

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This study is devoted to defining the optimal conditions for the nitriding of pure iron at atmospheric pressure by using NH3-Ar-C3H8 gas mixtures. After studying the mechanisms of phase formation and mass transfer at the gas-solid interface, a mathematical model is developed in order to predict the nitrogen transfer rate in the solid, the ε-carbonitride layer growth rate and the nitrogen and carbon concentration profiles. In order to validate the model and to show its possibilities, it is compared with thermogravimetric experiments, analyses and metallurgical observations (X-ray diffraction, optical microscopy and electron microprobe analysis). Results obtained allow us to demonstrate the sound correlation between the experimental results and the theoretical predictions.

Keywords: gaseous nitrocarburizing, kinetic model, diffusion, layer growth kinetic

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Authors: Hossein Agheshlui, Stephan Matthai

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In fractured rock masses open fractures tend to act as the main pathways of fluid flow. The permeability of a rock fracture depends on its aperture. The change of aperture with stress can cause a many-orders-of-magnitude change in the hydraulic conductivity at moderate compressive stress levels. In this study, the change of aperture in fragmented rocks is investigated using finite element analysis. A full 3D mechanical model of a simplified version of an outcrop analog is created and studied. A constant initial aperture value is applied to all fractures. Different far field stresses are applied and the change of aperture is monitored considering the block to block interaction. The fragmented rock layer is assumed to be sandwiched between softer layers. Frictional contact forces are defined at the layer boundaries as well as among contacting rock blocks. For a given in situ stress, the blocks slide and contact each other, resulting in new aperture distributions. A map of changed aperture is produced after applying the in situ stress and compared to the initial apertures. Subsequently, the permeability of the system before and after the stress application is compared.

Keywords: fractured rocks, mechanical model, aperture change due to stress, frictional interface

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Authors: Abdelsalam Omran Gebril

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Pollution and solid waste are the most important environmental problems plaguing the city of Benghazi as well as other cities and towns in Libya. These problems are caused by the lack of environmental planning and sound environmental management. Environmental planning is very important at present for the development of projects that preserve the environment, therefore, the planning process should be prioritized over the management process. Pollution caused by poor planning and environmental management exists not only in Benghazi but also in all other Libyan cities. This study was conducted through various field visits to several neighborhoods and areas within Benghazi as well as its neighboring regions. Follow-ups in these areas were conducted from March 2013 to October 2013 and documented by photographs. The existing methods of waste collection and means of transportation were investigated. Interviews were conducted with relevant authorities, including the Environment Public Authority in Benghazi and the Public Service Company of Benghazi. The objective of this study is to determine the causes of solid waste pollution in Benghazi City and its surrounding areas. Results show that solid waste pollution in Benghazi and its surrounding areas is the result of poor planning and environmental management, population growth, and the lack of hardware and equipment for the collection and transport of waste from the city to the landfill site. One of the most important recommendations in this study is the development of a complete and comprehensive plan that includes environmental planning and environmental management to reduce solid waste pollution.

Keywords: solid waste, pollution, environmental planning, management, Benghazi, Libya

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Authors: Anisa Gumel

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This study examines the present condition of solid waste management in Nigeria. The author explores the challenges and opportunities affecting municipal solid waste management in "Nigeria" and determines the most profound challenges by analysing the interdependence and interrelationship among identified variables. In this study, multiple stakeholders, including 15 waste management professionals interviewed online, were utilised to identify the difficulties and opportunities affecting municipal solid waste in Nigeria. The interviews were transcribed and coded using NVivo to produce pertinent variables. An online survey of Nigerian internet and social media users was done to validate statements made by experts on the identified variable. In addition, a panel of five experts participated in a focus group discussion to discover the most influential factors that influence municipal solid waste management in Nigeria by analysing the interrelationships as well as the driving and reliant power of variables. The results show significant factors affecting municipal solid waste in Nigeria, including inadequate funding, lack of knowledge, and absence of legislation, as well as behavioural, financial, technological, and legal concerns grouped into five categories. Some claims stated by experts in the interview are supported by the survey data, while others are not. In addition, the focus group reveals patterns, correlations, and driving forces between variables that have been analysed. This study will provide decision-makers with a roadmap for resolving important waste management concerns in Nigeria and managing scarce resources effectively. It will also help non-governmental organisations combat malaria in Nigeria and other underdeveloped nations. In addition, the work contributes to the literature for future scholars to consult.

Keywords: municipal solid waste, stakeholders, public, experts

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Authors: Devam Sheth

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Nuclear imaging with stress myocardial perfusion (stress test) is the preferred first line investigation for noninvasive evaluation of ischaemic heart condition. The sensitivity of this test is close to 90 % making it a very reliable test. However, rarely it gives a false negative result which can be explained by the phenomenon termed as “balanced ischaemia”. We present the case of a 78 year Caucasian female without any significant past cardiac history, who presents with chest pain and shortness of breath since one day. The initial ECG and cardiac enzymes were non-impressive. Few hours later, she had some substernal chest pain along with some ST segment depression in the lateral leads. Stress test comes back negative for any significant perfusion defects. However, given her typical symptoms, she underwent a cardiac catheterization which revealed significant triple vessel disease mandating her to get a bypass surgery. This unusual phenomenon of false nuclear stress test in the setting of positive ECG changes can be explained only by balanced ischemia wherein due to global myocardial ischemia, the stress test fails to reveal relative perfusion defects in the affected segments.

Keywords: balanced, false positive, ischemia, myocardial perfusion imaging

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Authors: K. Benhabib, X. Pierens, V-D Nguyen, G. Mimanne

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The main hypothesis of the dynamics of solid phase microextraction (SPME) is that steady-state mass transfer is respected throughout the SPME extraction process. It considers steady-state diffusion is established in the two phases and fast exchange of the analyte at the solid phase film/water interface. An improved model is proposed in this paper to handle with the situation when the analyte (atrazine) is in contact with colloid suspensions (carboxylate latex in aqueous solution). A mathematical solution is obtained by substituting the diffusion coefficient by the mean of diffusion coefficient between analyte and carboxylate latex, and also thickness layer by the mean thickness in aqueous solution. This solution provides an equation relating the extracted amount of the analyte to the extraction a little more complicated than previous models. It also gives a better description of experimental observations. Moreover, the rate constant of analyte obtained is in satisfactory agreement with that obtained from the initial curve fitting.

Keywords: pesticide, solid-phase microextraction (SPME) methods, steady state, analytical model

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Authors: Mohammad Y. Alfaifi

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Anything that poses a challenge or a threat to our well-being is a stress. Understanding the genetic material and cellular response of rats threatened with Repeated swimming stress provides insights that can influence human health. The aim of the present study was to assess the genetical damage and cytological changes caused by exposure of the test organism (Rattus rattus) to forced swimming stress. For this purpose, animals have been submerged in water path 15 minutes daily for 2 weeks. Following that, we performed a micronuclei (MN) test using MNNCE (Micronucleated normocromatic erythrocytes) and MNPCE (Micronucleated polychromatic erythrocytes), NDI (Nuclear division index) and cytological parameters using NDCI (nuclear division cytotoxicity index), necrotic and apoptotic cells in rat's bone marrow samples. Results showed that there was a slightly but not significant increase in the frequency of micronucleated as well as in cytological parameters in bone marrow cells.

Keywords: submergence stress, micronucleus, NDI, NDCI, toxicity, chromosomal aberrations

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Authors: Dimakatso Machetele, Clare Kelso, Thea Schoeman

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In developing countries such as India, China, and South Africa, disposal of household solid waste in rural areas is of great concern. Rural communities face numerous challenges that include the absence of waste collection services and sanitation facilities. The inadequate provision of waste collection and sanitation services results to the occurrence of infectious diseases e.g., malaria. The gap in the management of household solid waste between rural and urban communities, whereby urban communities have better waste management services compared to rural areas is an environmental injustice towards rural communities. The unequal distribution of infrastructure in South Africa’s waste management is a concern that stems from the spatial inequalities of the country’s apartheid history. The Limpopo province has a higher proportion of households without waste collection services from the municipality. The present research objectives are to investigate the public’s perceptions and factors contributing to the management of household solid waste in two contrasting rural Wards in the Greater Tzaneen Municipality. There is limited data and studies that have been conducted to understand the management of household solid waste in rural areas, and specifically, for the Greater Tzaneen Municipality located in the Limpopo province, South Africa. The findings of the study will propose recommendations to the Greater Tzaneen Municipality, rural municipalities in South Africa, and globally to explore sustainable methods to manage household solid waste and explore economic opportunities within the waste management sector to alleviate poverty in rural communities.

Keywords: rural, household solid wase, perceptions, waste management

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Authors: Jiawei Chen, Jia Qu, Dianwei Ju

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316L stainless steel has good mechanical and technological properties, has been widely used in shipbuilding and aerospace manufacturing. In order to understand the effect of strain rate on the yield limit of 316L stainless steel and the constitutive relationship of the materials at different strain rates, this paper used the INSTRON-4505 electronic universal testing machine to study the mechanical properties of the tensile specimen under quasi-static conditions. Meanwhile, the Zwick-Roell RKP450 intelligent oscillometric impact tester was used to test the tensile specimens at different strain rates. Through the above two kinds of experimental researches, the relationship between the true stress-strain and the engineering stress-strain at different strain rates is obtained. The result shows that the tensile yield point of 316L stainless steel increases with the increase of strain rate, and the real stress-strain curve of the 316L stainless steel has a better normalization than that of the engineering stress-strain curve. The real stress-strain curves can be used in the practical engineering of impact stretch to improve its safety.

Keywords: impact stretch, 316L stainless steel, strain rate, real stress-strain, normalization

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Authors: Poornima Gupta, Sadaf Siraj

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The study examined the organizational causes of organizational stress in women executives and entrepreneurs in India. This was done so that mediation strategies could be developed to combat the organizational stress experienced by them, in order to retain the female employees as well as attract quality talent. The data for this research was collected through the self- administered survey, from the women executives across various industries working at different levels in management. The research design of the study was descriptive and cross-sectional. It was carried out through a self-administered questionnaire filled in by the women executives and entrepreneurs in the NCR region. Multistage sampling involving stratified random sampling was employed. A total of 1000 questionnaires were distributed out of which 450 were returned and after cleaning the data 404 were fit to be considered for analyses. The overall findings of the study suggested that there were various job-related factors that induce stress. Fourteen factors were identified which were a major cause of stress among the working women by applying Factor analysis. The study also assessed the demographic factors which influence the stress in women executives across various industries. The findings show that the women, no doubt, were stressed by organizational factors. The mean stress score was 153 (out of a possible score of 196) indicating high stress. There appeared to be an inverse relationship between the marital status, age, education, work experience, and stress. Married women were less stressed compared to single women employees. Similarly, female employees 29 years or younger experienced more stress at work. Women having education up to 12th standard or less were more stressed compared to graduates and post graduates. Women who had spent more than two years in the same organization perceived more stress compared to their counterparts. Family size and income, interestingly, had no significant impact on stress. The study also established that the level of stress experienced by women across industries differs considerably. Banking sector emerged as the industry where the women experienced the most stress followed by Entrepreneurs, Medical, BPO, Advertising, Government, Academics, and Manufacturing, in that order. The results contribute to the better understanding of the personal and economic factors surrounding job stress and working women. It concludes that the organizations need to be sensitive to the women’s needs. Organizations are traditionally designed around men with the rules made by the men for the men. Involvement of women in top positions, decision making, would make them feel more useful and less stressed. The invisible glass ceiling causes more stress than realized among women. Less distinction between the men and women colleagues in terms of giving responsibilities, involvement in decision making, framing policies, etc. would go a long way to reduce stress in women.

Keywords: women, stress, gender in management, women in management

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Authors: D. Sersab, M. Aberkane

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Residual stresses, in high-density polyethylene (HDPE) pipes, result from a nonhomogeneous cooling rate that occurs between the inner and outer surfaces during the extrusion process in manufacture. Most known methods of measurements to determine the magnitude and profile of the residual stresses in the pipe wall thickness are layer removal and ring slitting method. The combined layer removal and ring slitting methods described in this paper involves measurement of the circumferential residual stresses with minimal local disturbance. The existing methods used for pipe geometry (ring slitting method) gives a single residual stress value at the bore. The layer removal method which is used more in flat plate specimen is implemented with ring slitting method. The method permits stress measurements to be made directly at different depth in the pipe wall and a well-defined residual stress profile was consequently obtained.

Keywords: residual stress, layer removal, ring splitting, HDPE, wall thickness

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Authors: Amani Waheed, Adel Mishriky, Rasha Farouk, Essam Abdallah, Sarah Hussein

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Background: Occupational stress plays a crucial role in professional drivers' health. They are exposed to high workloads, low physical activity, high demand and low decisions as well as poor lifestyle factors including poor diet, sedentary work, and smoking. Dyslipidemia is a well-established modifiable cardiovascular risk factor. Occupational stress and other forms of chronic stress have been associated with raised levels of atherogenic lipids. Although stress management has some evidence in improving lipid profile, the association between occupational stress and dyslipidemia is not clear. Objectives: To assess the relational between occupational stress and lipid profile among professional drivers. Methodology: A cross-sectional study conducted at a large company in Ismailia City, Egypt, where, 131 professional drivers divided into 44 car drivers, 43 bus drivers, and 44 truck drivers were eligible after applying exclusion criteria. Occupational stress index (OSI), non-occupational risk factors of dyslipidemia were assessed using interview structured questionnaire. Blood pressure, body mass index (BMI) and lipid profile were measured. Results: The mean of total OSI score was 79.98 ± 6.14. The total OSI score is highest among truck drivers (82.16 ± 4.62), then bus drivers (80.26 ± 6.02) and lowest among car drivers (77.55 ± 6.79) with statistically significant. Eighty percent had Dyslipidemia. The duration of driving hours per day, exposure to passive smoking and increased BMI were the risk factors. No statistical significance between Total OSI score and dyslipidemia. Using, logistic regression analysis, occupational stress, duration of driving hours per day, and BMI were positive significant predictors for dyslipidemia. Conclusion: Professional drivers are exposed to occupational stress. A high proportion of drivers have dyslipidemia. Total OSI score doesn't have statistically significant relation with dyslipidemia.

Keywords: body mass index, dyslipidaemia, occupational stress, professional drivers

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Authors: Fatemeh Najafi

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The major stress factor limiting crop growth and development of sesame (Sesamum indicum L.) is drought stress in arid and semiarid regions of the world. For this study the effects of water stress on some qualitative and quantitative traits in sesame germplasm was conducted in the Research Farm of Seed and Plant Improvement Institute, Karaj, in the crop year. Genotypes in a randomized complete block design with three replications in two environments (moisture stress and normal) were studied in regard of the seed weight, capsule weight, grain yield, biomass, plant height, number of capsules per plant, etc. The characteristics were evaluated based on the combined analysis. Irrigation was based on first class evaporation basin. After flowering stage drought stress was applied. The water deficit reduced growth period. Days to reach full ripening decreased so that the reduction was significant at the five percent level. Drought stress reduces yield and plant biomass. Genotypes based on combined analysis of these two traits were significant at the one percent level. Genotypes differ in terms of yield stress in terms of density plots, grain yield, days to first flowering and days to the half of the cap on the confidence level of five percent and traits of days to emergence of the first capsule and days to reach full ripening at the one percent level were significant. Other traits were not significant. The correlation of traits in circumstances of stress the number of seeds per capsule has the greatest impact on performance. The sensitivity and stress tolerance index was calculated. Based on the indicators, (Fars variety) and variety Karaj were identified as the most tolerant genotypes among the studied genotypes to drought stress. The highest sensitivity indicator of stress was related to genotype (FARS).

Keywords: sesamum, drought, stress, germplasm, resistance

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Authors: Sophaphan Intahphuak, Narong Pamala, Boonyaporn Yodkhong, Samuhavitayaa

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The amount of solid waste increases each year as a result of population growth, urbanization and economic expansion; however, there was little public cooperation in the segregation of solid waste due to the lack of awareness. This study aims to encourage all sectors in the community to participate in the development of a suitable model to reduce environmental waste by emerging the cultural context that bares a close relationship with Buddhism through faith and merit-making. The monks, involving stakeholder in the entire waste management system, help publicize the campaign on Buddhist holy days, religious ceremonies and they also teach people to be responsible for the garbage problem in the community. As for the garbage brought for merit-making, they are sold and the money is used to help build the pavilion. It was found that people can separate recycled garbage and the amount of solid waste slightly decrease. The results obtained suggest that the religion is not only the moral center of the community, it is also the center of community empowerment to consciousness in waste management.

Keywords: community empowerment, religion’s role, waste management, recycled garbage

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Authors: Rexa Pasha

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The aim of this study was to examine the relationship between depression, stress and life satisfaction with sleep disturbance among Islamic Azad University Ahvaz Branch students. Samples in the study included 230 students who were selected by stratified random sampling. For data collection, the Beck Depression Inventory, stress, life satisfaction and quality of sleep (PSQI) was used. Which all have acceptable reliability and validity. This study was correlation and Data analysis using Pearson correlation and multivariate regression significance level (pKeywords: depression, life satisfaction, sleep disorder, sleep disturbane

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Authors: Yaowaporn Sangsen, Kittisak Likhitwitayawuid, Boonchoo Sritularak, Kamonthip Wiwattanawongsa, Ruedeekorn Wiwattanapatapee

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Novel solid lipid nanoparticles (SLNs) were developed to improve oral bioavailability of oxyresveratrol (OXY). The SLNs were prepared by a high speed homogenization technique, at an effective speed and time, using Compritol® 888 ATO (5% w/w) as the solid lipid. The appropriate weight proportions (0.3% w/w) of OXY affected the physicochemical properties of blank SLNs. The effects of surfactant types on the properties of the formulations such as particle size and entrapment efficacy were also investigated. Conclusively, Tween 80 combined with soy lecithin was the most appropriate surfactant to stabilize OXY-loaded SLNs. The mean particle size of the optimized formulation was 134.40 ± 0.57 nm. In vitro drug release study, the selected S2 formulation showed a retarded release profile for OXY with no initial burst release compared to OXY suspension in the simulated gastrointestinal fluids. Therefore, these SLNs could provide a suitable system to develop for the oral OXY delivery.

Keywords: solid lipid nanoparticles, physicochemical properties, in vitro drug release, oxyresveratrol

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Authors: Ansal D'cruz, Anurup K., Saritha G. Parambath

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Physical and mental strain is a growing concern arising from various stressors in an urban context. However, these stressors are relatively less explored in the domain of urban design, especially in Indian cities where the central business district falls within the heritage core. An attempt is made in the context of the heritage core of Thiruvananthapuram city, Kerala, to understand and identify the connection between the built environment and urban stress. The criteria for establishing the indicators were obtained through a systematic literature review. A thorough study conducted in Gandhi Park, East Fort area using the identified criteria resulted in valuable insights into various urban stressors. Onsite surveys established the correlation between the built environment and user stress levels. The study concludes with guidelines for approaching urban stress in urban parks in an Indian context.

Keywords: urban stress, built environment, mental health, urban stressors, urban design

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Authors: Sakura Ganegama Bogodage, Andrew Yee Tat Leung

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This paper describes experimental, Computational Fluid Dynamics (CFD) and theoretical analysis of a cyclone performance, operated 1.0 g/m3 solid loading rate, at two different inlet velocities (5 m/s and 10 m/s). Comparing experimental results with theoretical and CFD simulation results, it is pronounced that the influence of solid in processing flow is significant than expected. Experimental studies based on gas- solid flows of cyclone separators are complicated as they required advanced sensitive measuring techniques, especially flow characteristics. Thus, CFD modelling and theoretical analysis are economical in analyzing cyclone separator performance but detailed clarifications of the application of these in cyclone separator performance evaluation is not yet discussed. The present study shows the limitations of influencing parameters of CFD and theoretical considerations, comparing experimental results and flow characteristics from CFD modelling.

Keywords: cyclone performance, inlet velocity, pressure drop, solid loading rate

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Authors: Faycal Benyahia, Abdelmohsen Albedah, Bel Abbes Bachir Bouiadjra

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In this paper, the finite element analysis is applied to study the performance of the bonded composite reinforcement or repair for reducing stress concentration at a semi-circular lateral notch and repairing cracks emanating from this kind of notch. The effects of the adhesive properties on the variation of the stress intensity factor at the crack tip were highlighted. The obtained results show that the stress concentration factor at the notch tip is reduced about 30% and the maximal reduction of the stress intensity factor is about 80%. The adhesive properties must be optimized in order to increase the performance of the patch repair or reinforcement.

Keywords: bonded repair, notch, crack, adhesive, composite

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Authors: Sheila R. Pai, Rekha D. Kini, Amrutha Mary

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Objective: To assess and compare the cardiac autonomic activity after mental stress among the wards of normal and hypertensive parents. Methods: The study included 67 subjects, 30 of them had a parental history of hypertension and rest 37 had normotensive parents. Subjects were divided into control group (wards of normotensive parents) and Study group (wards of hypertensive parents). The height, weight were noted, and Body Mass Index (BMI) was also calculated. The mental stress test was carried out. Blood pressure (BP) and electro cardiogram (ECG) was recorded during normal breathing and after mental stress test. Heart rate variability (HRV) analysis was done by time domain method HRV was recorded and analyzed by the time-domain method. Analysis of HRV in the time-domain was done using the software version 1.1 AIIMS, New Delhi. The data obtained was analyzed using student’s t-test followed by Mann-Whitney U-test and P < 0.05 was considered significant. Results: There was no significant difference in systolic blood pressure and diastolic blood pressure (DBP) between study group and control group following mental stress. In the time domain analysis, the mean value of pNN50 and RMSSD of the study group was not significantly different from the control group after the mental stress test. Conclusion: The study thus concluded that there was no significant difference in HRV between study group and control group following mental stress.

Keywords: heart rate variability, time domain analysis, mental stress, hypertensive

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Authors: S. K. Thind, Aparjot Kaur

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Heat stress is one of the major environmental factors drastically reducing wheat production. Crop heat tolerance can be enhanced by preconditioning of plants by exogenous application of osmoprotectants. Presently, the effect of trehalose pretreatment (at 1 mM, and 1.5 nM) under heat stress of 35±2˚C (moderate) and 40±2˚ (severe) for four and eight hour was conducted in wheat (Tricticum aestivum L.) genotypes viz. HD2967, PBW 175, PBW 343, PBW 621, and PBW 590. Heat stress affects wide spectrum of physiological processes within plants that are irreversibly damaged by stress. Membrane thermal stability (MTS) and cell viability was significantly decreased under heat stress for eight hours. Pretreatment with trehalose improved MTS and cell viability under stress and this effect was more promotory with higher concentration. Thermal stability of photosynthetic apparatus differed markedly between genotypes and Hill reaction activity was recorded more in PBW621 followed by C306 as compared with others. In all genotypes photolysis of water showed decline with increase in temperature stress. Trehalose pretreatment helped in sustaining Hill reaction activity probably by stabilizing the photosynthetic apparatus against heat-induced photo inhibition. Both plant growth and development were affected by temperature in both shoot and root under heat stress. The reduction was compensated partially by trehalose (1.5 mM) application. Adaption to heat stress is associated with the metabolic adjustment which led to accumulation of soluble sugars including non-reducing and reducing for their role in adaptive mechanism. Higher acid invertase activity in shoot of tolerant genotypes appeared to be a characteristic for stress tolerance. As sucrose synthase play central role in sink strength and in studied wheat genotype was positively related to dry matter accumulation. The duration of heat stress for eight hours had more severe effect on these parameters and trehalose application at 1.5 mM ameliorated it to certain extent.

Keywords: heat stress, Triticum aestivum, trehalose, membrane thermal stability, triphenyl tetrazolium chloride, reduction test, growth, sugar metabolism

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Authors: Maria Magdy Danial Riad

Abstract:

The hypothalamic-pituitary-adrenal axis is activated by the adaptation stress, and this might result in the alteration of certain behavioral signs. The primary purpose of this paper is the adaptive stress effect on dietary behavior, which is directly correlated with changes in plasma cortisol levels. Physiological factors have a role in systems of adaptation and stress. Objectives: Ten clinically healthy cats were included in the study, and they were all kept in the same setting. Methods: On days 1, 5, 9, and 10 of the stay, each cat's behavior was observed through ethograms, and the serum cortisol levels were also measured at the same time. Significant behavioral changes in terms of nutrition were seen on the first day, with 50% of the participants not feeding and all participants not watering. Toward the study's conclusion, between days 5 and 9, there were no longer any discernible changes in the dietary habits, which might be attributed to the adaptation to the new living conditions. Cortisol variations in serological levels were consistent with behavioral changes; in 50% of the participants under observation, there was a substantial increase in values (p<0.05), which gradually declined as the study came to an end.

Keywords: domestic cats, ewes, nutritional behavior, adjustment stress, plasma cortisol levels

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Authors: Praveen Kumar, Nitin Kumar, Hemant Kumar

Abstract:

The modernization of computer technology and commercial computational fluid dynamic (CFD) simulation has given better detailed results as compared to experimental investigation techniques. CFD techniques are widely used in different field due to its flexibility and performance. Evaluation of pipeline erosion is complex phenomenon to solve by numerical arithmetic technique, whereas CFD simulation is an easy tool to resolve that type of problem. Erosion wear behaviour due to solid–liquid mixture in the slurry pipeline has been investigated using commercial CFD code in FLUENT. Multi-phase Euler-Lagrange model was adopted to predict the solid particle erosion wear in 22.5° pipe bend for the flow of bottom ash-water suspension. The present study addresses erosion prediction in three dimensional 22.5° pipe bend for two-phase (solid and liquid) flow using finite volume method with standard k-ε turbulence, discrete phase model and evaluation of erosion wear rate with varying velocity 2-4 m/s. The result shows that velocity of solid-liquid mixture found to be highly dominating parameter as compared to solid concentration, density, and particle size. At low velocity, settling takes place in the pipe bend due to low inertia and gravitational effect on solid particulate which leads to high erosion at bottom side of pipeline.

Keywords: computational fluid dynamics (CFD), erosion, slurry transportation, k-ε Model

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Authors: Deepa Gandhi, Pravin K. Naoghare, Amit Bafana, Krishnamurthi Kannan, Saravanadevi Sivanesana

Abstract:

Oxidative stress is known to depreciate normal functioning of osteoblast cells. Present study reports oxidative/inflammatory signatures in fluoride exposed human osteosarcoma (HOS) cells and its possible association with the genes involved in bone developmental pathway. Microarray analysis was performed to understand the possible molecular mechanisms of stress-mediated bone lose in HOS cells. Cells were chronically exposed with sub-lethal concentration of fluoride. Global gene expression is profiling revealed 34 up regulated and 2598 down-regulated genes, which were associated with several biological processes including bone development, osteoblast differentiation, stress response, inflammatory response, apoptosis, regulation of cell proliferation. Microarray data were further validated through qRT-PCR and western blot analyses using key representative genes. Based on these findings, it can be proposed that chronic exposure of fluoride may impair bone development via oxidative and inflammatory stress. The present finding also provides important biological clues, which will be helpful for the development of therapeutic targets against diseases related bone.

Keywords: bone, HOS cells, microarray, stress

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Authors: Byung Wook Yang, Jong Dae Park, Wang Soo Shin, Ji-Hyeon Song, Seo-Yun Choi, Boo-Yong Lee, Young Tae Hahm

Abstract:

Korean ginseng (Panax ginseng C. A. Meyer) is frequently taken orally as a traditional herbal medicine with ginsenosides as the main pharmacological component in Asian countries, and its use is increasing worldwide. Recently, the increase in global temperature has been reported to cause various kinds of biological disorders induced by heat stress in human. The standardized black ginseng extract (SBGE; KGR-BG1) was developed in our biological screening experiment on the thermo-regulation, whose chemical characteristics were evaluated as ginsenoside Rg1, Rb1, Rg3(S), as well as Re, Rf, Rg2(S), Rh1(S), Rh2(S), and Rg5+Rk1. Heat stress responses such as body weight, food intake, water consumption have been measured when treated with Standardized Black Ginseng Extract (SBGE) in the animal experiment and also, biomarkers. SBGE treated group has been found to inhibit a decrease in body weight, a decrease in food intake and an increase in the water consumption when compared with non-treated group against environmental heat stress. These results suggest that SBGE might have a protective effect against environmental heat stress. And also, the several factors of stress response on the immune system need to be done for further studies and its evaluation is in progress.

Keywords: ginseng, ginsenoside, standardization, heat stress, immunomodulatory effect

Procedia PDF Downloads 294