Search results for: cyclic stress ratio
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8519

Search results for: cyclic stress ratio

7679 Effects of Benzo(k)Fluoranthene, a Polycyclic Aromatic Hydrocarbon, on DNA Damage and Oxidative Stress in Marine Gastropod Morula Granulata

Authors: Jacky Bhagat, Baban S Ingole

Abstract:

In this study, in vivo experiments were carried out to investigate the effects of a toxic polycyclic aromatic hydrocarbon (PAH), benzo(k)fluoranthene (B[k]F), on marine gastropod, Morula granulata collected from Goa, west coast of India. Snails were exposed to different concentrations of B(k)F (1, 10, 25 and 50 µg/L) for 96 h. The genotoxic effects were evaluated by measuring DNA strand breaks using alkaline comet assay and oxidative stress were measured with the help of battery of biomarkers such as superoxide dismutase (SOD) catalase (CAT), glutathione-s-transferase (GST), and lipid peroxidation (LPO). Concentration-dependent increase in percentage tail DNA (TDNA) was observed in snails exposed to B(k)F. Exposure concentrations above 1 µg/L of B(k)F, showed significant increase in SOD activity and LPO value in snails. After 96 h, SOD activity were found to be doubled for 50 µg/L of B(k)F with reference to control. Significant increase in CAT and GST activity was observed at all exposure conditions at the end of the exposure time. Our study showed that B(k)F induces oxidative stress in snails which further lead to genotoxic damage.

Keywords: benzo(k)fluoranthene, comet assay, gastropod, oxidative stress

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7678 Racial Microaggressions: Experiences among International Students in Australia and Its Impact on Stress and Psychological Wellbeing

Authors: Hugo M. Gonzales, Ke Ni Chai, Deanne Mary King

Abstract:

International students are underrepresented in Australian health literature, and this population is especially vulnerable to the well-documented negative impacts associated with racial microaggressions in their adjustment to settling in the new society, as well as to the many challenges they already face as international students. This study investigated the prevalence of racial microaggressions among international students and their impact on stress and psychological well-being. This research was conducted during the COVID-19 pandemic, which has been documented to contribute to anti-Asian racism. Participants included 54 international students, of which 72% were Asian. The Racial and Ethnic Microaggressions Scale (REMS), Perceived Stress Scale (PSS), and the Perceived General Wellbeing Indicator (PGWBI) were used to measure the participants’ responses. All participants reported experiencing racial microaggression in the last six months, and significant correlations and regression models were found between REMS, certain elements of the PSS scale, and time in Australia. Despite the small sample size, this research corroborated outcomes from recent studies and provided insight into the prevalence and impact of racial microaggressions among such populations, highlighting the need for further exploration.

Keywords: racial microaggressions, international students, racism, REMS, microaggressions in Australia, stress, psychological wellbeing

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7677 Characterization of Transcription Factors Involved in Early Defense Response during Interaction of Oil Palm Elaeis guineensis Jacq. with Ganoderma boninense

Authors: Sakeh N. Mohd, Bahari M. N. Abdul, Abdullah S. N. Akmar

Abstract:

Oil palm production generates high export earnings to many countries especially in Southeast Asian region. Infection by necrotrophic fungus, Ganoderma boninense on oil palm results in basal stem rot which compromises oil palm production leading to significant economic loss. There are no reliable disease treatments nor promising resistant oil palm variety has been cultivated to eradicate the disease up to date. Thus, understanding molecular mechanisms underlying early interactions of oil palm with Ganoderma boninense may be vital to promote preventive or control measure of the disease. In the present study, four months old oil palm seedlings were infected via artificial inoculation of Ganoderma boninense on rubber wood blocks. Roots of six biological replicates of treated and untreated oil palm seedlings were harvested at 0, 3, 7 and 11 days post inoculation. Next-generation sequencing was performed to generate high-throughput RNA-Seq data and identify differentially expressed genes (DEGs) during early oil palm-Ganoderma boninense interaction. Based on de novo transcriptome assembly, a total of 427,122,605 paired-end clean reads were assembled into 30,654 unigenes. DEGs analysis revealed upregulation of 173 transcription factors on Ganoderma boninense-treated oil palm seedlings. Sixty-one transcription factors were categorized as DEGs according to stringent cut-off values of genes with log2 ratio [Number of treated oil palm seedlings/ Number of untreated oil palm seedlings] ≥ |1.0| (corresponding to 2-fold or more upregulation) and P-value ≤ 0.01. Transcription factors in response to biotic stress will be screened out from abiotic stress using reverse transcriptase polymerase chain reaction. Transcription factors unique to biotic stress will be verified using real-time polymerase chain reaction. The findings will help researchers to pinpoint defense response mechanism specific against Ganoderma boninense.

Keywords: Ganoderma boninense, necrotrophic, next-generation sequencing, transcription factors

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7676 Laser Ultrasonic Diagnostics and Acoustic Emission Technique for Examination of Rock Specimens under Uniaxial Compression

Authors: Elena B. Cherepetskaya, Vladimir A. Makarov, Dmitry V. Morozov, Ivan E. Sas

Abstract:

Laboratory studies of the stress-strain behavior of rocks specimens were conducted by using acoustic emission and laser-ultrasonic diagnostics. The sensitivity of the techniques allowed changes in the internal structure of the specimens under uniaxial compressive load to be examined at micro- and macro scales. It was shown that microcracks appear in geologic materials when the stress level reaches about 50% of breaking strength. Also, the characteristic stress of the main crack formation was registered in the process of single-stage compression of rocks. On the base of laser-ultrasonic echoscopy, 2D visualization of the internal structure of rocky soil specimens was realized, and the microcracks arising during uniaxial compression were registered.

Keywords: acoustic emission, geomaterial, laser ultrasound, uniaxial compression

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7675 Wheat Yield and Yield Components under Raised Bed Planting System

Authors: Hamidreza Miri, Farahnaz Momtazi

Abstract:

Wheat is one of the most important crops in Fars province, and because of water shortage, there is a great emphasis on its water use efficiency in the production field. A field experiment was conducted in 2021 and 2022 in order to evaluate wheat yield and its components in raised planting system in Arsanjan, Fars province. The experiment was conducted as a split plot with three irrigation treatments (irrigation equal to evapotranspiration, 80% of evapotranspiration irrigation (moderate drought stress), and 60% of evapotranspiration irrigation (severe drought stress)) as the main plot and three planting methods (conventional flat planting, 60 cm raised bed planting and 120 cm raised bed planting) as a subplot. The results indicated that drought stress significantly decreased traits such as plant height, grain yield, ear number, seed number, and biological yield while increasing seed protein. Raised bed planting significantly increased the traits in comparison with conventional flat planting. So that plating with a 120 cm raised bed increased grain yield by 22.1% and 25.9% in the first and second years, respectively. This increase was 17% for biological, 75 for ear number, and 21% for seed number. Planting in raised bed system reduced the adverse effect of drought stress on wheat traits. In conclusion, based on the observed results planting in raised bed system can be adopted as an appropriate planting pattern for improving yield and water productivity in experimental regions and similar climates.

Keywords: wheat, raised bed planting, drought stress, yield, water use

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7674 Evaluation on Heat and Drought Tolerance Capacity of Chickpea

Authors: Derya Yucel, Nigar Angın, Dürdane Mart, Meltem Turkeri, Volkan Catalkaya, Celal Yucel

Abstract:

Chickpea (Cicer arietinum L.) is one of the important legumes widely grown for dietery proteins in semi-arid Mediteranean climatic conditions. To evaluate the genetic diversity with improved heat and drought tolerance capacity in chickpea, thirty-four selected chickpea genotypes were tested under different field-growing conditions (rainfed winter sowing, irrigated-late sowing and rainfed-late sowing) in 2015 growing season. A factorial experiment in randomized complete block design with 3 reps was conducted at the Eastern Mediterranean Research Institute Adana, Turkey. Based on grain yields under different growing conditions, several indices were calculated to identify economically higher-yielding chickpea genotypes with greater heat and drought tolerance capacity. Average across chickpea genotypes, the values of tolerance index, mean productivity, yield index, yield stability index, stress tolerance index, stress susceptibility index, and geometric mean productivity were ranged between 1.1 to 218, 38 to 202, 0.3 to 1.7, 0.2 to 1, 0.1 to 1.2, 0.02 to 1.4, and 36 to 170 for drought stress and 3 to 54, 23 to 118, 0.3 to 1.7, 0.4 to 0.9, 0.2 to 2, 0.2to 2.3, and 23 to 118 for heat stress, respectively. There were highly significant differences observed among the tested chickpea genotypes response to drought and heat stresses. Among the chickpea genotypes, the Aksu, Arda, Çakır, F4 09 (X 05 TH 21-16189), FLIP 03-108 were identified with a higher drought and heat tolerance capacity. Based on our field studies, it is suggested that the drought and heat tolerance indicators of plants can be used by breeders to select stress-resistant economically productive chickpea genotypes suitable to grow under Mediteranean climatic conditions.

Keywords: irrigation, rainfed, stress susceptibility, tolerance indice

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7673 The Effectiveness of Intensive Short-Term Dynamic Psychotherapy on Ambiguity Tolerance, Emotional Intelligence and Stress Coping Strategies in Financial Market Traders

Authors: Ahmadreza Jabalameli, Mohammad Ebrahimpour Borujeni

Abstract:

This study aims to evaluate the effectiveness of intensive short-term dynamic psychotherapy (ISTDP) on ambiguity tolerance, emotional intelligence and stress coping strategies in financial market traders. The methodology of this study was quasi-experimental, pre-test and post-test with control group. The statistical population of this study includes all students at Jabalameli Information Technology Academy in 2022. Among them, 30 people were selected by voluntary sampling through interviews, and were randomly divided into two experimental and control groups of 51 people. And the components were measured according to McLain Ambiguity Tolerance Questionnaire, Bar-On Emotional Intelligence and Lazarus Stress Coping Strategies. The data were obtained by SPSS software and were analyzed by using multivariate analysis of covariance. The results indicate that intensive short-term dynamic psychotherapy influences the emotional intelligence as well as the ambiguity tolerance of traders.

Keywords: ISTDP, ambiguity tolerance, trading, emotional intelligence, stress

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7672 An Original and Suitable Induction Method of Repeated Hypoxic Stress by Hydralazine to Investigate the Integrity of an in Vitro Contact Co-Culture Blood Brain Barrier Model

Authors: Morgane Chatard, Clémentine Puech, Nathalie Perek, Frédéric Roche

Abstract:

Several neurological disorders are linked to repeated hypoxia. The impact of such repeated hypoxic stress, on endothelial cells function of the blood-brain barrier (BBB) is little studied in the literature. Indeed, the study of hypoxic stress in cellular pathways is complex using hypoxia exposure because HIF 1α (factor induced by hypoxia) has a short half life. Our study presents an innovative induction method of repeated hypoxic stress, more reproducible, which allows us to study its impacts on an in vitro contact co-culture BBB model. Repeated hypoxic stress was induced by hydralazine (a mimetic agent of hypoxia pathway) during two hours and repeated during 24 hours. Then, BBB integrity was assessed by permeability measurements (transendothelial electrical resistance and membrane permeability), tight junction protein expressions (cell-ELISA and confocal microscopy) and by studying expression and activity of efflux transporters. First, this study showed that repeated hypoxic stress leads to a BBB’s dysfunction illustrated by a significant increase in permeability. This loss of membrane integrity was linked to a significant decrease of tight junctions’ protein expressions, facilitating a possible transfer of potential cytotoxic compounds in the brain. Secondly, we demonstrated that brain microvascular endothelial cells had set-up defence mechanism. These endothelial cells significantly increased the activity of their efflux transporters which was associated with a significant increase in their expression. In conclusion, repeated hypoxic stress lead to a loss of BBB integrity with a decrease of tight junction proteins. In contrast, endothelial cells increased the expression of their efflux transporters to fight against cytotoxic compounds brain crossing. Unfortunately, enhanced efflux activity could also lead to reducing pharmacological drugs delivering to the brain in such hypoxic conditions.

Keywords: BBB model, efflux transporters, repeated hypoxic stress, tigh junction proteins

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7671 Elevated Temperature Shot Peening for M50 Steel

Authors: Xinxin Ma, Guangze Tang, Shuxin Yang, Jinguang He, Fan Zhang, Peiling Sun, Ming Liu, Minyu Sun, Liqin Wang

Abstract:

As a traditional surface hardening technique, shot peening is widely used in industry. By using shot peening, a residual compressive stress is formed in the surface which is beneficial for improving the fatigue life of metal materials. At the same time, very fine grains and high density defects are generated in the surface layer which enhances the surface hardness, either. However, most of the processes are carried out at room temperature. For high strength steel, such as M50, the thickness of the strengthen layer is limited. In order to obtain a thick strengthen surface layer, elevated temperature shot peening was carried out in this work by using Φ1mm cast ion balls with a speed of 80m/s. Considering the tempering temperature of M50 steel is about 550 oC, the processing temperature was in the range from 300 to 500 oC. The effect of processing temperature and processing time of shot peening on distribution of residual stress and surface hardness was investigated. As we known, the working temperature of M50 steel can be as high as 315 oC. Because the defects formed by shot peening are unstable when the working temperature goes higher, it is worthy to understand what happens during the shot peening process, and what happens when the strengthen samples were kept at a certain temperature. In our work, the shot peening time was selected from 2 to 10 min. And after the strengthening process, the samples were annealed at various temperatures from 200 to 500 oC up to 60 h. The results show that the maximum residual compressive stress is near 900 MPa. Compared with room temperature shot peening, the strengthening depth of 500 oC shot peening sample is about 2 times deep. The surface hardness increased with the processing temperature, and the saturation peening time decreases. After annealing, the residual compressive stress decreases, however, for 500 oC peening sample, even annealing at 500 oC for 20 h, the residual compressive stress is still over 600 MPa. However, it is clean to see from SEM that the grain size of surface layers is still very small.

Keywords: shot peening, M50 steel, residual compressive stress, elevated temperature

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7670 Computer Simulation Approach in the 3D Printing Operations of Surimi Paste

Authors: Timilehin Martins Oyinloye, Won Byong Yoon

Abstract:

Simulation technology is being adopted in many industries, with research focusing on the development of new ways in which technology becomes embedded within production, services, and society in general. 3D printing (3DP) technology is fast developing in the food industry. However, the limited processability of high-performance material restricts the robustness of the process in some cases. Significantly, the printability of materials becomes the foundation for extrusion-based 3DP, with residual stress being a major challenge in the printing of complex geometry. In many situations, the trial-a-error method is being used to determine the optimum printing condition, which results in time and resource wastage. In this report, the analysis of 3 moisture levels for surimi paste was investigated for an optimum 3DP material and printing conditions by probing its rheology, flow characteristics in the nozzle, and post-deposition process using the finite element method (FEM) model. Rheological tests revealed that surimi pastes with 82% moisture are suitable for 3DP. According to the FEM model, decreasing the nozzle diameter from 1.2 mm to 0.6 mm, increased the die swell from 9.8% to 14.1%. The die swell ratio increased due to an increase in the pressure gradient (1.15107 Pa to 7.80107 Pa) at the nozzle exit. The nozzle diameter influenced the fluid properties, i.e., the shear rate, velocity, and pressure in the flow field, as well as the residual stress and the deformation of the printed sample, according to FEM simulation. The post-printing stability of the model was investigated using the additive layer manufacturing (ALM) model. The ALM simulation revealed that the residual stress and total deformation of the sample were dependent on the nozzle diameter. A small nozzle diameter (0.6 mm) resulted in a greater total deformation (0.023), particularly at the top part of the model, which eventually resulted in the sample collapsing. As the nozzle diameter increased, the accuracy of the model improved until the optimum nozzle size (1.0 mm). Validation with 3D-printed surimi products confirmed that the nozzle diameter was a key parameter affecting the geometry accuracy of 3DP of surimi paste.

Keywords: 3D printing, deformation analysis, die swell, numerical simulation, surimi paste

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7669 Liquefaction Susceptibility of Tailing Storage Facility-Comparison of National Centre for Earthquake Engineering Research and Finite Element Methods

Authors: Mehdi Ghatei, Masoomeh Lorestani

Abstract:

Upstream Tailings Storage Facilities (TSFs) may experience slope instabilities due to soil liquefaction, especially in regions known to be seismically active. In this study, liquefaction susceptibility of an upstream-raised TSF in Western Australia was assessed using two different approaches. The first approach assessed liquefaction susceptibility using Cone Penetration Tests with pore pressure measurement (CPTu) as described by the National Centre for Earthquake Engineering Research (NCEER). This assessment was based on the four CPTu tests that were conducted on the perimeter embankment of the TSF. The second approach used the Finite Element (FE) method with application of an equivalent linear model to predict the undrained cyclic behavior, the pore water pressure and the liquefaction of the materials. The tailings parameters were estimated from the CPTu profiles and from the laboratory tests. The cyclic parameters were estimated from the literature where test results of similar material were available. The results showed that there was a good agreement, in the liquefaction susceptibility of the tailings material, between the NCEER and FE methods with equivalent linear model.

Keywords: liquefaction , CPTU, NCEER, finite element method, equivalent linear model

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7668 Quality of Life among Mothers of Children with Autism Spectrum Disorder in Saudi Arabia

Authors: Asma Alsaleh, Kara Makara

Abstract:

Autistic spectrum disorder (ASD) is a neurodevelopmental condition characterized by difficulties with communication and interaction. Besides presenting challenges for the ASD individual, the condition can entail negative outcomes for those who care for them, most often mothers. While this issue has been studied substantially in Western society, less is known about how mothers in the Arab world are affected by raising an ASD child. This study sought to gain insights into this area by assessing quality of life and stress in mothers with (n = 25) and without (n = 25) ASD children in Riyadh (Saudi Arabia) by using, respectively, the World Health Organization Quality of Life Assessment-BREF (WHOQOL-BREF) and the Parenting Stress Index-Short Form (PSI-SF). Data pertaining to income and education were also attained to investigate how socioeconomic factors interact with the above-mentioned variables. The analysis revealed that total stress scores and scores on the individual subscales of the PSI-SF were significantly higher for the mothers with an ASD child compared to those without an ASD child, though the opposite was true of quality of life scores. Moreover, increased income was associated with increased quality of life and decreased stress. While there were not main effects of education, there were interactions between education, whether children were ASD or non-ASD, and the outcome variables. These results suggest that mothers of ASD children in an Arab culture are at increased risk of negative outcomes relative to mothers of typically developing children, and, therefore, this study may act as a foundation for the delivery of interventions to assist mothers in this position.

Keywords: autism, education, income, mothers, quality of life, stress

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7667 Computation and Validation of the Stress Distribution around a Circular Hole in a Slab Undergoing Plastic Deformation

Authors: Sherif D. El Wakil, John Rice

Abstract:

The aim of the current work was to employ the finite element method to model a slab, with a small hole across its width, undergoing plastic plane strain deformation. The computational model had, however, to be validated by comparing its results with those obtained experimentally. Since they were in good agreement, the finite element method can therefore be considered a reliable tool that can help gain better understanding of the mechanism of ductile failure in structural members having stress raisers. The finite element software used was ANSYS, and the PLANE183 element was utilized. It is a higher order 2-D, 8-node or 6-node element with quadratic displacement behavior. A bilinear stress-strain relationship was used to define the material properties, with constants similar to those of the material used in the experimental study. The model was run for several tensile loads in order to observe the progression of the plastic deformation region, and the stress concentration factor was determined in each case. The experimental study involved employing the visioplasticity technique, where a circular mesh (each circle was 0.5 mm in diameter, with 0.05 mm line thickness) was initially printed on the side of an aluminum slab having a small hole across its width. Tensile loading was then applied to produce a small increment of plastic deformation. Circles in the plastic region became ellipses, where the directions of the principal strains and stresses coincided with the major and minor axes of the ellipses. Next, we were able to determine the directions of the maximum and minimum shear stresses at the center of each ellipse, and the slip-line field was then constructed. We were then able to determine the stress at any point in the plastic deformation zone, and hence the stress concentration factor. The experimental results were found to be in good agreement with the analytical ones.

Keywords: finite element method to model a slab, slab undergoing plastic deformation, stress distribution around a circular hole, visioplasticity

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7666 Effect of Gel Concentration on Physical Properties of an Electrochromic Device

Authors: Sharan K. Indrakar, Aakash B. Prasad, Arash Takshi, Sesha Srinivasan, Elias K. Stefanakos

Abstract:

In this work, we present an exclusive study on the effect of the feeding ratio of polyaniline-based redox-active gel layer on electrical and optical properties of innovative electrochromic devices (ECs). An electrochromic device consisting of polyaniline (PANI) has a redox-active gel electrolyte placed between two conducting transparent fluorine-doped tin oxide glass substrates. The redox-active composite gel is a mixture of different concentrations of aniline (monomer), a water-soluble polymer poly (vinyl alcohol), hydrochloric acid, and an oxidant. The EC device shows the color change from dark green to transparent for the applied potential between -0.5 V to +2.0 V. The coloration and decoloration of the ECs were tested for electrochemical behavior using techniques such as cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The optical transparency of the EC devices was examined at two different biasing voltage conditions under UV-visible spectroscopic technique; the result showed 65% transmittance at 564 nm and zero transmittance when the cell was biased at 0.0 V and 2.0 V, the synthesized mol fraction gel was analyzed for surface morphology and structural properties by scanning electron microscopy and Fourier transformer spectroscopy.

Keywords: electrochromic, gel electrolyte, polyaniline, conducting polymer

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7665 The Effect of Vertical Shear-link in Improving the Seismic Performance of Structures with Eccentrically Bracing Systems

Authors: Mohammad Reza Baradaran, Farhad Hamzezarghani, Mehdi Rastegari Ghiri, Zahra Mirsanjari

Abstract:

Passive control methods can be utilized to build earthquake resistant structures, and also to strengthen the vulnerable ones. One of the most effective, yet simple passive control methods is the use of vertical shear-links (VSL) in systems with eccentric bracing. In fact, vertical shear-links dissipate the earthquake energy and act like a ductile fuse. In this paper, we studied the effect of this system in increasing the ductility and energy dissipation and also modeled the behavior of this type of eccentric bracing, and compared the hysteresis diagram of the modeled samples with the laboratory samples. We studied several samples of frames with vertical shear-links in order to assess the behavior of this type of eccentric bracing. Each of these samples was modeled in finite element software ANSYS 9.0, and was analyzed under the static cyclic loading. It was found that vertical shear-links have a more stable hysteresis loops. Another analysis showed that using honeycomb beams as the horizontal beam along with steel reinforcement has no negative effect on the hysteresis behavior of the sample.

Keywords: vertical shear-link, passive control, cyclic analysis, energy dissipation, honeycomb beam

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7664 A Solution to Analyze the Geosynthetic Reinforced Piled Embankments Considering Pile-Soil Interaction

Authors: Feicheng Liu, Weiming Liao, Jianjing Zhang

Abstract:

A pile-supported embankment with geosynthetic-reinforced mat (PSGR embankment) has been considered as an effective solution to reduce the total and differential settlement of the embankment constructed over soft soil. In this paper, a new simplified method proposed firstly incorporates the load transfer between piles and surrounding soil and the settlement of pile, and also considers arching effect in embankment fill, membrane effect of geosynthetic reinforcement, and subsoil resistance, to evaluate the behavior of PSGR embankment. Subsoil settlement is assumed to consist of two parts:(1) the settlement of subsoil surface between piles equivalent to that of pile caps assuming the geosynthetic reinforcement without deformation yet; (2) the subsoil subsiding along with the geosynthetic deforming, and the deflected geosynthetic being considered as centenary. The force equilibrium, including loads acting on the upper surface of geosynthetic, subsoil resistance, as well as the stress-strain relationship of the geosynthetic reinforcement at the edge of pile cap, is established, thus the expression of subsoil resistance is deduced, and subsequently the tension of geosynthetic and stress concentration ratio between piles can be calculated. The proposed method is validated through observed data from three field tests and also compared with other eight analytical solutions available in the literature. In addition, a sensitive analysis is provided to demonstrate the influence of with/without considering pile-soil interaction for evaluating the performance of PSGR embankment.

Keywords: pile-supported embankment, geosynthetic, analytical solution, soil arching effect, the settlement of pile, sensitive analysis

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7663 A Comparative Study of Force Prediction Models during Static Bending Stage for 3-Roller Cone Frustum Bending

Authors: Mahesh Chudasama, Harit Raval

Abstract:

Conical sections and shells of metal plates manufactured by 3-roller conical bending process are widely used in the industries. The process is completed by first bending the metal plates statically and then dynamic roller bending sequentially. It is required to have an analytical model to get maximum bending force, for optimum design of the machine, for static bending stage. Analytical models assuming various stress conditions are considered and these analytical models are compared considering various parameters and reported in this paper. It is concluded from the study that for higher bottom roller inclination, the shear stress affects greatly to the static bending force whereas for lower bottom roller inclination it can be neglected.

Keywords: roller-bending, static-bending, stress-conditions, analytical-modeling

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7662 Examining the Relationship Between Job Stress And Burnout Among Academic Staff During The Covid-19 Pandemic; The Importance Of Emotional Intelligence

Authors: Parisa Gharibi Khoshkar

Abstract:

The global outbreak of Covid-19 forced a swift shift in the education sector, transitioning from traditional in-person settings to remote online setups in a short period. This abrupt change, coupled with health risks and other stressors such as the lack of social interaction, has had a negative impact on academic staff, leading to increased job-related stress and psychological pressures that can result in burnout. To address this, the current research aims to investigate the relationship between job stress and burnout among academic staff in Hebron, Palestine. Furthermore, this study examines the moderating role of emotional intelligence to gain a deeper understanding of its effects in reducing burnout among academic staff and teachers. This research posits that emotional intelligence plays a vital role in helping individuals manage job-related stress and anxiety, thereby preventing burnout. Using a self-administered questionnaire, the study gathered data from 185 samples comprising teachers and administrative staff from two universities in Hebron. The data was analyzed using moderated regression analysis, ANOVA model, and interaction plots. The findings indicate that work-related stress has a direct and significant influence on burnout. Moreover, the current results highlight that emotional intelligence serves as a key determinant in managing the negative effects of the pandemic-induced stress that can lead to burnout among individuals. Given the high-demand nature of the education sector, this research strongly recommends that school authorities take proactive measures to provide much-needed support to academic staff, enabling them to better cope with job stress and fostering an environment that prioritizes individuals' wellbeing. The results of this study hold practical implications for both scholars and practitioners, as they highlight the importance of emotional intelligence in managing stress and anxiety effectively. Understanding the significance of emotional intelligence can aid in implementing targeted interventions and support systems to promote the well-being and resilience of academic staff amidst challenging circumstances.

Keywords: job stress, burnout, employee wellbeing, emotional intelligence, industrial organizational psychology, human resource management, organizational psychology

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7661 Preparation and Characterization of Chitosan Nanoparticles for Delivery of Oligonucleotides

Authors: Gyati Shilakari Asthana, Abhay Asthana, Dharm Veer Kohli, Suresh Prasad Vyas

Abstract:

Purpose: The therapeutic potential of oligonucleotide (ODN) is primarily dependent upon its safe and efficient delivery to specific cells overcoming degradation and maximizing cellular uptake in vivo. The present study is focused to design low molecular weight chitosan nanoconstructs to meet the requirements of safe and effectual delivery of ODNs. LMW-chitosan is a biodegradable, water soluble, biocompatible polymer and is useful as a non-viral vector for gene delivery due to its better stability in water. Methods: LMW chitosan ODN nanoparticles (CHODN NPs) were formulated by self-assembled method using various N/P ratios (moles ratio of amine groups of CH to phosphate moieties of ODNs; 0.5:1, 1:1, 3:1, 5:1, and 7:1) of CH to ODN. The developed CHODN NPs were evaluated with respect to gel retardation assay, particle size, zeta potential and cytotoxicity and transfection efficiency. Results: Complete complexation of CH/ODN was achieved at the charge ratio of 0.5:1 or above and CHODN NPs displayed resistance against DNase I. On increasing the N/P ratio of CH/ODN, the particle size of the NPs decreased whereas zeta potential (ZV) value increased. No significant toxicity was observed at all CH concentrations. The transfection efficiency was increased on increasing N/P ratio from 1:1 to 3:1, whereas it was decreased with further increment in N/P ratio upto 7:1. Maximum transfection of CHODN NPs with both the cell lines (Raw 267.4 cells and Hela cells) was achieved at N/P ratio of 3:1. The results suggest that transfection efficiency of CHODN NPs is dependent on N/P ratio. Conclusion: Thus the present study states that LMW chitosan nanoparticulate carriers would be acceptable choice to improve transfection efficiency in vitro as well as in vivo delivery of oligonucleotide.

Keywords: LMW-chitosan, chitosan nanoparticles, biocompatibility, cytotoxicity study, transfection efficiency, oligonucleotide

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7660 Application of Arbuscular Mycorrhizal Fungi as Biologically Based Strategy for Mitigation of Adverse Impact of Salt Stress on Wheat

Authors: Abeer Hashem, Khalid F. Almutairi, Ulkar Ibrahimova, Elsayed Fathi Abdallah

Abstract:

Salinity poses a significant challenge to wheat production, necessitating the exploration of strategies to mitigate its adverse effects. The present investigation aims to study the impact of arbuscular mycorrhizal fungi (AMF) application to improve plant tolerance in terms of growth, carbohydrate, photosynthetic characteristics, and antioxidant enzyme activities under salt stress conditions. So, a randomized complete block design with five replications was employed comprising various treatments of AMF application under salinity stress (200mM), and control samples were used for each treatment. The obtained results demonstrated significantly that AMF used in this study showed beneficial impacts in all parameters used as sensitive monitor for relation of plant-salt microbe interaction. The root colonization by AMF showed the highest plant growth criteria, relative water content, soluble sugar, starch, and total non-structural carbohydrates under both control and salinity stress conditions. Moreover, the application of AMF-treated plants showed the highest soluble protein concentration and activity in leaves and antioxidant enzymes (catalase, superoxide dismutase, guaiacol peroxidase). These findings highlight the potential impact of AMF application as a biologically based strategy to manage the mitigation of salt stress on wheat, which increases the availability of many salt marsh habitats for sustainable agriculture of such strategy crops.

Keywords: arbuscular mycorrhizal fungi, salt stress, plant growth criteria, soluble protein, antioxidant enzymes, wheat plant

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7659 Hierarchical Optimization of Composite Deployable Bridge Treadway Using Particle Swarm Optimization

Authors: Ashraf Osman

Abstract:

Effective deployable bridges that are characterized by an increased capacity to weight ratio are recently needed for post-disaster rapid mobility and military operations. In deployable bridging, replacing metals as the fabricating material with advanced composite laminates as lighter alternatives with higher strength is highly advantageous. This article presents a hierarchical optimization strategy of a composite bridge treadway considering maximum strength design and bridge weight minimization. Shape optimization of a generic deployable bridge beam cross-section is performed to achieve better stress distribution over the bridge treadway hull. The developed cross-section weight is minimized up to reserving the margins of safety of the deployable bridging code provisions. Hence, the strength of composite bridge plates is maximized through varying the plies orientation. Different loading cases are considered of a tracked vehicle patch load. The orthotropic plate properties of a composite sandwich core are used to simulate the bridge deck structural behavior. Whereas, the failure analysis is conducted using Tsai-Wu failure criterion. The naturally inspired particle swarm optimization technique is used in this study. The proposed technique efficiently reduced the weight to capacity ratio of the developed bridge beam.

Keywords: CFRP deployable bridges, disaster relief, military bridging, optimization of composites, particle swarm optimization

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7658 Comparison with Mechanical Behaviors of Mastication in Teeth Movement Cases

Authors: Jae-Yong Park, Yeo-Kyeong Lee, Hee-Sun Kim

Abstract:

Purpose: This study aims at investigating the mechanical behaviors of mastication, according to various teeth movement. There are three masticatory cases which are general case and 2 cases of teeth movement. General case includes the common arrange of all teeth and 2 cases of teeth movement are that one is the half movement location case of molar teeth in no. 14 tooth seat after extraction of no. 14 tooth and the other is no. 14 tooth seat location case of molar teeth after extraction in the same case before. Materials and Methods: In order to analyze these cases, 3 dimensional finite element (FE) model of the skull were generated based on computed tomography images, 964 dicom files of 38 year old male having normal occlusion status. An FE model in general occlusal case was used to develop CAE procedure. This procedure was applied to FE models in other occlusal cases. The displacement controls according to loading condition were applied effectively to simulate occlusal behaviors in all cases. From the FE analyses, von Mises stress distribution of skull and teeth was observed. The von Mises stress, effective stress, had been widely used to determine the absolute stress value, regardless of stress direction and yield characteristics of materials. Results: High stress was distributed over the periodontal area of mandible under molar teeth when the mandible was transmitted to the coronal-apical direction in the general occlusal case. According to the stress propagation from teeth to cranium, stress distribution decreased as the distribution propagated from molar teeth to infratemporal crest of the greater wing of the sphenoid bone and lateral pterygoid plate in general case. In 2 cases of teeth movement, there were observed that high stresses were distributed over the periodontal area of mandible under teeth where they are located under the moved molar teeth in cranium. Conclusion: The predictions of the mechanical behaviors of general case and 2 cases of teeth movement during the masticatory process were investigated including qualitative validation. The displacement controls as the loading condition were applied effectively to simulate occlusal behaviors in 2 cases of teeth movement of molar teeth.

Keywords: cranium, finite element analysis, mandible, masticatory action, occlusal force

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7657 Impact of Capital Structure, Dividend Policy and Sustainability on Value of Firm: A Case Study of Spinning Textile Sector of Pakistan

Authors: Zahid Ahmad, Samia Yousaf

Abstract:

The main purpose of this study is to evaluate and assess the financial position, operating performance, and recent outlook of the companies. This study investigates the impact of capital structure, dividend policy and sustainability on the value of firms of textile spinning sector of Pakistan which is listed on Pakistan stock exchange. The panel data technique has been applied to this group of textile sector which is textile spinning. This study covers the last ten years of time period. All the data related to the variables have been collected from the annual reports and financial statements of the textile sector firms. There are differently related determinants to measure the capital structure which are fixed assets turnover ratio, debt ratio, equity ratio, debt to equity ratio, assets tangibility, and shareholder’s equity. Dividend policy is being measured by two determinants which are earning per share (EPS) and dividend payout ratio. Sustainability is being measured by three suitable factors which are sales growth, gross profit margin ratio and firm size. These are three independent variables and their determinants of this study. Value of firm is measured through the return on asset (ROA). Capital structure is at the top of the list among all the three variables. According to the results of this research work, somewhere all the three variables generates positive and significant effect on the firm’s performance and its growth.

Keywords: capital structure, dividend policy, panel data, sustainability

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7656 A Study on Low Stress Mechanical Properties of Denim Fabric for Hand Evaluation

Authors: S. P. Raut, S. K. Soni, A. W. Kolhatkar

Abstract:

Denim is widely used by every age of people all over the world. As the use of denim is increasing progressively, till now the handle properties of denim fabric not reported at significant level. In the present study, five commercial denim fabric samples were used. Denim samples, weighing from 8.5oz/sq yds to 14.5 oz/sq yds, were processed as per standard commercial procedure for denim finishing. These finished denim samples were tested on Kawabata Evaluation System(KES) for low stress mechanical properties. The results of KES values are used for calculation of Total Hand value(THV) using equation for summer suit. The obtained result for THV using equation for summer suit for denim samples is in the range from 1.62 to 3.30. These values of low stress mechanical properties values given by KES, can be used to engineer the denim fabric for bottom wear.

Keywords: denim, handle value, Kawabata evaluation system, objective evaluation

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7655 Turbulence Measurement Over Rough and Smooth Bed in Open Channel Flow

Authors: Kirti Singh, Kesheo Prasad

Abstract:

A 3D Acoustic Doppler velocimeter was used in the current investigation to quantify the mean and turbulence characteristics in non-uniform open-channel flows. Results are obtained from studies done in the laboratory, analysing the behavior of sand particles under turbulent open channel flow conditions flowing through rough, porous beds. Data obtained from ADV is used to calculate turbulent flow characteristics, Reynolds stresses and turbulent kinetic energy. Theoretical formulations for the distribution of Reynolds stress and the vertical velocity have been constructed using the Reynolds equation and the continuity equation of 2D open-channel flow. The measured Reynolds stress profile and the vertical velocity are comparable with the derived expressions. This study uses the Navier-Stokes equations for analysing the behavior of the vertical velocity profile in the dominant region of full-fledged turbulent flows in open channels, and it gives a new origination of the profile. For both wide and narrow open channels, this origination can estimate the time-averaged primary velocity in the turbulent boundary layer's outer region.

Keywords: turbulence, bed roughness, logarithmic law, shear stress correlations, ADV, Reynolds shear stress

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7654 Relationship between Body Composition and Balance in Young Adults

Authors: Ferruh Taspinar, Gulce K. Seyyar, Gamze Kurt, Eda O. Okur, Emrah Afsar, Ismail Saracoglu, Betul Taspinar

Abstract:

Overweight and obesity has been associated with postural balance. The aim of this study was to investigate the relationship between body composition and balance. One hundred and thirty two young adults (58 male, 74 female) were included in the study. Mean age of participants were found as 21.21±1.51 years. Body composition (body mass index, total body fat ratio, total body muscle ratio) and balance (right anterior, right postero-medial, right postero-lateral, left anterior, left postero-medial, left postero-lateral) were evaluated by Tanita BC-418 and Y balance test, respectively. Pearson correlation analysis was used to evaluate the correlation between the parameters. Significance level in statistical analysis was accepted as 0.05. According to results, no correlation was found between body mass index and balance parameters. There was negative correlation between total body fat ratio and balance parameters (r=0.419-0.509, p˂0.05). On the other hand, positive correlation was found between total body muscle ratio and balance parameters (r=0.390-0.494, p˂0.05). This study demonstrated that body fat and muscle ratio affects the balance. Body composition should be considered in rehabilitation programs including postural balance training.

Keywords: balance, body composition, body mass, young adults

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7653 Calculation Analysis of an Axial Compressor Supersonic Stage Impeller

Authors: Y. Galerkin, E. Popova, K. Soldatova

Abstract:

There is an evident trend to elevate pressure ratio of a single stage of a turbo compressors - axial compressors in particular. Whilst there was an opinion recently that a pressure ratio 1,9 was a reasonable limit, later appeared information on successful modeling tested of stages with pressure ratio up to 2,8. The Authors recon that lack of information on high pressure stages makes actual a study of rational choice of design parameters before high supersonic flow problems solving. The computer program of an engineering type was developed. Below is presented a sample of its application to study possible parameters of the impeller of the stage with pressure ratio π*=3,0. Influence of two main design parameters on expected efficiency, periphery blade speed and flow structure is demonstrated. The results had lead to choose a variant for further analysis and improvement by CFD methods.

Keywords: supersonic stage, impeller, efficiency, flow rate coefficient, work coefficient, loss coefficient, oblique shock, direct shock

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7652 Evaluation of Relationship between Job Stress Dimensions with Occupational Accidents in Industrial Factories in Southwest of Iran

Authors: Ali Ahmadi, Maryam Abbasi, Mohammad Mehdi Parsaei

Abstract:

Background: Stress in the workplace today is one of the most important public health concerns and a serious threat to the health of the workforce worldwide. Occupational stress can cause occupational events and reduce quality of life. As a result, it has a very undesirable impact on the performance of organizations, companies, and their human resources. This study aimed to evaluate the relationship between job stress dimensions and occupational accidents in industrial factories in Southwest Iran. Materials and Methods: This cross-sectional study was conducted among 200 workers in the summer of 2023 in the Southwest of Iran. To select participants, we used a convenience sampling method. The research tools in this study were the Health and Safety Executive (HSE) stress questionnaire with 35 questions and 7 dimensions and demographic information. A high score on this questionnaire indicates that there is low job stress and pressure. All workers completed the informed consent form. Univariate analysis was performed using chi-square and T-test. Multiple regression analysis was used to estimate the odds ratios (OR) and 95% confidence interval (CI) for the association of stress-related factors with job accidents in participants. Stata 14.0 software was used for analysis. Results: The mean age of the participants was 39.81(6.36) years. The prevalence of job accidents was 28.0% (95%CI: 21.0, 34.0). Based on the results of the multiple logistic regression with the adjustment of the effect of the confounding variables, one increase in the score of the demand dimension had a protective impact on the risk of job accidents(aOR=0.91,95%CI:0.85-0.95). Additionally, an increase in one of the scores of the managerial support (aOR=0.89, 95% CI: 0.83-0.95) and peer support (aOR=0.76, 95%CI: 0.67-87) dimensions was associated with a lower number of job accidents. Among dimensions, an increase in the score of relationship (aOR=0.89, 95%CI: 0.80-0.98) and change (aOR=0.86, 95%CI: 0.74-0.96) reduced the odds of the accident's occurrence among the workers by 11% and 16%, respectively. However, there was no significant association between role and control dimensions and the job accident (p>0.05). Conclusions: The results show that the prevalence of job accidents was alarmingly high. Our results suggested that an increase in scores of dimensions HSE questioners is significantly associated with a decrease the accident occurrence in the workplace. Therefore, planning to address stressful factors in the workplace seems necessary to prevent occupational accidents.

Keywords: HSE, Iran, job stress occupational accident, safety, occupational health

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7651 E-Tongue Based on Metallo-Porphyrins for Histamine Evaluation

Authors: A. M. Iordache, S. M. Iordache, V. Barna, M. Elisa, I. C. Vasiliu, C. R. Stefan, I. Chilibon, I. Stamatin, S. Caramizoiu, C. E. A. Grigorescu

Abstract:

The general objective of the presentation is the development of an e-tongue like sensor based on modified screen printed electrode (SPE) structures with a receptor part made of porphyrins/metalloporphyrins chemically bound to graphene (the sensitive assembly) to act as antennas and “capture” the histamine molecules. Using a single, ultra-sensitive electrochemical sensor, we measured the concentration of histamine, a compound which is strongly connected to the level of freshness in foods (the caution level of histamine is 50 ppm, whereas the maximum accepted levels range from 200 ppm to 500 ppm). Our approach for the chemical immobilization of the porphyrins onto the surface of the graphenes was via substitution reaction: a solution of graphene in SOCl2 was heated to 800C for 6 hours. Upon cooling, the metallo-porphyrins were added and ultrasonicated for 4 hours. The solution was then allowed to cool to room temperature and then centrifuged in order to separate the deposit. The sensitive assembly was drop casted onto the carbon SPE and cyclic voltammetry was performed in the presence of histamine. The reaction is quasi-reversible and the sensor showed an oxidation potential for histamine at 600 mV. The results indicate a linear dependence of concentration of histamine as function of intensity. The results are reproducible; however the chemical stability of the sensitive assembly is low.

Keywords: histamine, cyclic voltammetry, metallo-porphyrin, food freshness

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7650 The Role of Physical Activities in Improving the Psychological State, Reducing Stress and Anxiety Resulting from the Corona (Covid-19) Pandemic

Authors: Saidia Houari

Abstract:

The current coronavirus pandemic (COVID-19) is a special and unusual reality. It can affect people physically, but also psychologically. Indeed, in such a context, many people will experience reactions of stress, anxiety and depression, and Sports is known to be a great in improving the effectiveness of the nervous system and mental health. Professor Ango Frubuze“many studies proved that sports play an important role in fighting psychological tension and some other psychological problems, such as depression and sleep difficulties, but on condition of practicing them properly,choosing the kind that generates comfort and happiness for man “ .The sports university professor in the German city of Cologne added that the effort exerted during the exercise works on restoring balance to the stress hormones like cortisol.The case report provides an insight into the COVID-19 current situation and represents a picture of the current state of mental health and an overview of novel coronavirus (Covid-19) outbreaks in some countries of the world. Some procedures taken to combat the coronavirus. We proposed the practice of physical activities during the quarantine period, and we showed their importance and their positive effects.

Keywords: COVID-19, psycholiqical impacts, stress, physical activities

Procedia PDF Downloads 54