Search results for: stress and strain

Authors: B. S. Yadav, A. Mani, S. Srivastava

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Chickpea (Cicer arietinum L.) is an annual, self-pollinating, diploid (2n = 2x = 16) pulse crop that ranks second in world legume production after common bean (Phaseolus vulgaris). ICC 4958 flowers approximately 39 days after sowing under peninsular Indian conditions and the crop matures in less than 90 days in rained environments. The estimated collective yield losses due to abiotic stresses (6.4 million t) have been significantly higher than for biotic stresses (4.8 million t). Most legumes are known to be salt sensitive, and therefore, it is becoming increasingly important to produce cultivars tolerant to high-salinity in addition to other abiotic and biotic stresses for sustainable chickpea production. Our aim was to identify the genes that are involved in the defence mechanism against heavy metal toxicity in chickpea and establish the biological network of heavy metal toxicity in chickpea. ICC4958 variety of chick pea was taken and grown in normal condition and 150µM concentration of different heavy metal salt like CdCl₂, K₂Cr2O₇, NaAsO₂. At 15th day leave samples were collected and stored in RNA Later solution microarray was performed for checking out differential gene expression pattern. Our studies revealed that 111 common genes that involved in defense mechanism were up regulated and 41 genes were commonly down regulated during treatment of 150µM concentration of CdCl₂, K₂Cr₂O₇, and NaAsO₂. Biological network study shows that the genes which are differentially expressed are highly connected and having high betweenness and centrality.

Keywords: abiotic stress, biological network, chickpea, microarray

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Authors: Binish Ahmed

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Corporate Social Responsibility (CSR) is regarded as voluntary behaviors that contribute to the social welfare based on the concept of sustainable development. The corporations should not only stress on their economic and business outcomes but also pay attention to their effect on the society and environment. It could attract investors and customers, as well as maintain a positive interaction with the government. In spite of the broad diffusion, and its potential significance to employees' perspective, CSR is now examined and has built-in Organizational Behavior (OB), and Human Resource Management (HRM) look into the broad structure of relationship between employees' perspective, work attitudes and behavior to improve the research on CSR. The purpose of this research is to investigate the impact of employees’ perception of CSR on work attitudes and behaviors of employees. A conceptual framework is proposed, based on the literature and practices. The research would conduct the primary data survey of convenient sampling from the employees and managers-using detailed questionnaire- to address the following questions. The survey of 180 respondents of age greater than 20 having at least six-month experience from companies based in Karachi are source of data. The application of professional empirical models for data analysis and interpretation are source to draw the conclusion. 1. What are the dynamics of CSR in an organization? Why is it important to have a CSR department? What sort of business approach are CSR activities practiced? Do CSR activities improve the quality of life of workplace? And, how it linked with welfare of society? 2. How the positive job attitude and behavior does encourage the employees about the perception of CSR? How is it linked with the job satisfaction? What is the relationship between employees’ perception of CSR and job satisfaction?

Keywords: corporate social responsibility, job satisfaction, organizational commitment, work behaviors

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Authors: Seyyed Abbas Mojtabavi, Mojtaba Fatzaneh Moghadam, Masoud Mahdavi

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Steel Metal Shear Wall is one of the most common and widely used energy dissipation systems in structures, which is used today as a damping system due to the increase in the construction of metal structures. In the present study, the shear wall of the steel plate with dimensions of 5×3 m and thickness of 0.024 m was modeled with 2 floors of total height from the base level with finite element method in Abaqus software. The loading is done as a concentrated load at the upper point of the shear wall on the second floor based on step type buckle. The mesh in the model is applied in two directions of length and width of the shear wall, equal to 0.02 and 0.033, respectively, and the mesh in the models is of sweep type. Finally, it was found that the steel plate shear wall with cavity (CSPSW) compared to the SPSW model, S (Mises), Smax (In-Plane Principal), Smax (In-Plane Principal-ABS), Smax (Min Principal) increased by 53%, 70%, 68% and 43%, respectively. The presence of cavities has led to an increase in the estimated stresses, but their presence has caused critical stresses and critical deformations created to be removed from the inner surface of the shear wall and transferred to the desired sections (regular cavities) which can be suggested as a solution in seismic design and improvement of the structure to transfer possible damage during the earthquake and storm to the desired and pre-designed location in the structure.

Keywords: steel plate shear wall, abacus software, finite element method, , boundary element, seismic structural improvement, von misses stress

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Authors: P. Bublíkova, P. Halodova, H. K. Namburi, J. Stodolna, J. Duchon, O. Libera

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Neutron radiation-induced microstructural changes cause degradation of mechanical properties and the lifetime reduction of reactor internals during nuclear power plant operation. Investigating the effects of neutron irradiation on mechanical properties of the irradiated material (hardening, embrittlement) is challenging and time-consuming. Although the fast neutron spectrum has the major influence on microstructural properties, the thermal neutron effect is widely investigated owing to Irradiation-Assisted Stress Corrosion Cracking firstly observed in BWR stainless steels. In this study, 300-series austenitic stainless steels used as material for NPP's internals were examined after neutron irradiation at ~ 15 dpa. Although several nanoindentation experimental publications are available to determine the mechanical properties of ion irradiated materials, less is available on neutron irradiated materials at high dpa tested in hot-cells. In this work, we present particular methodology developed to determine the mechanical properties of neutron irradiated steels by nanoindentation technique. Furthermore, radiation-induced damage in the specimens was investigated by High Resolution - Transmission Electron Microscopy (HR-TEM) that showed the defect features, particularly Frank loops, cavity microstructure, radiation-induced precipitates and radiation-induced segregation. The results of nanoindentation measurements and associated nanoscale defect features showed the effect of irradiation-induced hardening. We also propose methodologies to optimized sample preparation for nanoindentation and microscotructural studies.

Keywords: nanoindentation, thermal neutrons, radiation hardening, transmission electron microscopy

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Authors: Sujata Sharma, Avinash Singh, Lovely Gautam, Pradeep Sharma, Mau Sinha, Asha Bhushan, Punit Kaur, Tej P. Singh

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Peptidyl-tRNA hydrolase (Pth) Pth is an essential bacterial enzyme that catalyzes the release of free tRNA and peptide moeities from peptidyl tRNAs during stalling of protein synthesis. In order to design inhibitors of Pth from Pseudomonas aeruginosa (PaPth), we have determined the structures of PaPth in its native state and in the bound states with two compounds, amino acylate-tRNA analogue (AAtA) and 5-azacytidine (AZAC). The peptidyl-tRNA hydrolase gene from Pseudomonas aeruginosa was amplified by Phusion High-Fidelity DNA Polymerase using forward and reverse primers, respectively. The E. coliBL21 (λDE3) strain was used for expression of the recombinant peptidyl-tRNA hydrolase from Pseudomonas aeruginosa. The protein was purified using a Ni-NTA superflow column. The crystallization experiments were carried out using hanging drop vapour diffusion method. The crystals diffracted to 1.50 Å resolution. The data were processed using HKL-2000. The polypeptide chain of PaPth consists of 194 amino acid residues from Met1 to Ala194. The centrally located β-structure is surrounded by α-helices from all sides except the side that has entrance to the substrate binding site. The structures of the complexes of PaPth with AAtA and AZAC showed the ligands bound to PaPth in the substrate binding cleft and interacted with protein atoms extensively. The residues that formed intermolecular hydrogen bonds with the atoms of AAtA included Asn12, His22, Asn70, Gly113, Asn116, Ser148, and Glu161 of the symmetry related molecule. The amino acids that were involved in hydrogen bonded interactions in case of AZAC included, His22, Gly113, Asn116, and Ser148. As indicated by fittings of two ligands and the number of interactions made by them with protein atoms, AAtA appears to be a more compatible with the structure of the substrate binding cleft. However, there is a further scope to achieve a better stacking than that of O-tyrosyl moiety because it is not still ideally stacked. These observations about the interactions between the protein and ligands have provided the information about the mode of binding of ligands, nature and number of interactions. This information may be useful for the design of tight inhibitors of Pth enzymes.

Keywords: peptidyl tRNA hydrolase, Acinetobacter baumannii, Pth enzymes, O-tyrosyl

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Authors: Muhammad Ejaz1

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Rework has been defined as: "The unnecessary effort of re-doing a process or activity that was incorrectly implemented the first time." A great threat to the construction industry is rework. By and large due attention has not been given to avoid the causes of reworks, resulting time and cost over runs, in civil engineering projects. Besides these direct consequences, there might also be indirect consequences, such as stress, de-motivation or loss of future clients. When delivered products do not meet the requirements or expectations, work often has to be redone. Rework occurs in various phases of the construction process or in various divisions of a company. Rework can occur on the construction site or in a management department due to for example bad materials management. Rework can also have internal or external origins. Changes in clients’ expectations are an example of an external factor that might lead to rework. Rework can cause many costs to be higher than calculated at the start of the project. Rework events can have many different origins and for this research they have been categorized into four categories; changes, errors, omissions, and damages. The research showed that the major source of reworks were non professional attitude from technical hands and ignorance of total quality management principals by stakeholders. It also revealed that sources of reworks have not major differences among project categories. The causes were further analyzed by interviewing employees. Based on existing literature an extensive list of rework causes was made and during the interviews the interviewees were asked to confirm or deny statements regarding rework causes. The causes that were most frequently confirmed can be grouped into the understanding categories. 56% (max) of the causes are change-related, 30% (max) is error-related and 18% (max) falls into another category. Therefore, by recognizing above mentioned factors, reworks can be reduced to a great extent.

Keywords: total quality management, construction industry, cost overruns, rework, material management, client’s expectations

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Authors: Clara Oliver, Oibar Martinez

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This paper is intended to reveal the severity of electrostatic discharge (ESD) effects in electronic and optoelectronic devices by performing sensitivity tests based on Human Body Model (HBM) standard. We explain here the HBM standard in detail together with the typical failure modes associated with electrostatic discharges. In addition, a prototype of electrostatic charge generator has been designed, fabricated, and verified to stress electronic devices, which features a compact high voltage source. This prototype is inexpensive and enables one to do a battery of pre-compliance tests aimed at detecting unexpected weaknesses to static discharges at the component level. Some tests with different devices were performed to illustrate the behavior of the proposed generator. A set of discharges was applied according to the HBM standard to commercially available bipolar transistors, complementary metal-oxide-semiconductor transistors and light emitting diodes. It is observed that high current and voltage ratings in electronic devices not necessarily provide a guarantee that the device will withstand high levels of electrostatic discharges. We have also compared the result obtained by performing the sensitivity tests based on HBM with a real discharge generated by a human. For this purpose, the charge accumulated in the person is monitored, and a direct discharge against the devices is generated by touching them. Every test has been performed under controlled relative humidity conditions. It is believed that this paper can be of interest for research teams involved in the development of electronic and optoelectronic devices which need to verify the reliability of their devices in terms of robustness to electrostatic discharges.

Keywords: human body model, electrostatic discharge, sensitivity tests, static charge monitoring

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Authors: Wanutchaya Duanginta, Napaporn Apiratmateekul, Tippawan Sangkaew, Sunaree Wekinhirun, Kunchit Kongros, Wanvisa Treebuphachatsakul

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Thailand has a tropical climate with an average outdoor ambient air temperature of over 30°C, which can exceed manufacturer recommendations for the storage of glucose test strips. This study monitored temperature and humidity at actual sites of five sub-district health promoting hospitals (HPH) in Phitsanulok Province for the storage of glucose test strips in refrigerated conditions. Five calibrated data loggers were placed at the actual sites for glucose test strip storage at five HPHs for 8 weeks between April and June. For the stress test, two lot numbers of glucose test strips, each with two glucose meters, were kept in a plastic box with desiccants and placed in a refrigerator with the temperature calibrated to 4°C and at room temperature (RT). Temperature and humidity in the refrigerator and at RT were measured every hour for 30 days. The mean temperature for storing test strips at the five HPHs ranged from 29°C to 33°C, and three of the five HPHs (60%) had a mean temperature above 30°C. The refrigerator temperatures were 3.8 ± 2.0°C (2.0°C to 6.5°C), and relative humidity was 51 ± 2% (42 to 54%). The maximum of blood glucose testing by glucose meters when the test strips were stored in a refrigerator were not significantly different (p > 0.05) from unstressed test strips for both glucose meters using amperometry-GDH-PQQ and amperometry-GDH-FAD principles. Opening the test strip vial daily resulted in higher variation than when refrigerated after a single-use. However, the variations were still within an acceptable range. This study concludes that glucose tested strips can be stored in plastic boxes in a refrigerator if it is well-controlled for temperature and humidity. Storage of glucose-tested strips in the refrigerator during hot and humid weather may be useful for HPHs with limited air conditioners.

Keywords: environmental stressed test, thermal stressed test, quality control, point-of-care testing

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Authors: Rosita Kanapeckaite

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The modern operational military environment is a combination of factors such as change, uncertainty, complexity and ambiguity. Stiehm (2002) refers to such situations as VUCA situations. VUCA is an acronym commonly used to describe the volatility, uncertainty, complexity and ambiguity of various situations and conditions. Increasingly fast-paced military operations require military personnel to demonstrate readiness and resilience under stressful conditions in order to maintain the optimum cognitive and physical performance necessary to achieve success. Military resilience can be defined as the ability to cope with the negative effects of setbacks and associated stress on military performance and combat effectiveness. In the volatile, uncertain, complex and ambiguous modern operational environment, both current and future operations require and place a higher priority on enhancing and maintaining troop readiness and resilience to win decisively in multidimensional combat. This paper explores the phenomenon of soldiers' psychological resilience, theories of leadership, and commitment to the organisation. The aim of the study is to examine the relationship between soldiers' psychological resilience, leadership style and commitment to the organisation. The study involved 425 professional soldiers, the research method was a questionnaire survey. The instruments used were measures of psychological resilience, leadership styles and commitment to the organisation. Results: transformational leadership style predicts higher psychological resilience, and psychologically resilient professional servicemen are more committed to the organisation. The study confirms the importance of soldiers' psychological resilience for their commitment to the organisation. The paper also discusses practical applications.

Keywords: resilience, commitment, solders, leadership style

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Authors: Saima Batool, Saima Rafique

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Background and Objective: Pandemics like COVID-19 adversely affect children’s behavior and psychological development by disrupting routine life activities. Children of healthcare workers are exposed additionally due to the fear of parental exposure to the virus. The objective of this study was to assess the perception of frontline healthcare workers (HCWs) regarding the psychological impact of the COVID-19 pandemic on their children. We also sought to identify the difference in the psychological impact on children of male and female healthcare workers. Methods: A survey questionnaire was developed comprising 10 questions about the perception of HCWs regarding the psychological impact of COVID-19 on their children. It was distributed both online and face-to-face among 150 healthcare professionals working in training and non-training posts in 4 public and 5 nongovernment hospitals in Pakistan. The mean and standard deviation were calculated for each survey item using Statistical Package for the Social Sciences 26.0. Results: The response rate was 71.3%, and the majority (64.2%) of the healthcare professionals were ≥30 years of age. Ninety-two HCWs (85.98%) either agreed or strongly agreed that parental separation from their kids for long hours during the pandemic had a negative psychological impact on their children. There was a significant difference in the perceived psychological impact of COVID-19 on the children of male and female HCWs, with a mean survey score of 2.29 ± 1.82 and 1.69 ± 0.79, respectively (t = 2.29, p-value = 0.024). Conclusion: Children of healthcare workers experience more stress and anxiety because of long duty hours and working in high-risk settings. Continuous psychological support and counseling services may be adopted formally to prevent unforeseen adverse events or any long-term negative impact on their physical and mental health.

Keywords: healthcare workers, pandemic, COVID-19, anxiety, psychological

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Authors: Eric Tardif, Nicolas Meylan

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Recent studies suggest that the consolidation of episodic memory is better achieved through repeated retrieval than with the use of concept mapping or repeated study. Although such laboratory results highly appeal to educationalists, it remains to be shown whether they can be directly used in a classroom setting. Forty-five college students (42 girls; mean age 16.1 y/o) were asked to remember pairs of biology-related words (e.g. mitochondria-energy) in two configurations. The first configuration consisted of a three-minute study of pairs of words followed by a final one-minute test in which the first word of a pair was shown and the subject asked to write down the second associated word. This procedure was repeated three times. The second configuration consisted of a one-minute study of a list of pairs of words, which was immediately followed by a one-minute test. This procedure was repeated 6 times. Subjects filled out a small questionnaire assessing their general mood, level of fatigue, stress and motivation to do the exercise. One week later, subjects were given a final test using the same words. A total of 8 lists of words were studied and tested during the semester. Results showed that subjects recalled more correct words when using the second configuration, both within the study period and one week later, confirming laboratory findings. However, the general performance (mean items recalled) as well as the motivation to do the exercise gradually decreased during the semester. Motivation was positively correlated with performance (r=0.77, p<0.05). The results suggest that laboratory findings may provide some applications in education but other variables inherent to the classroom setting must also be considered.

Keywords: long-term, episodic memory, consolidation, retrieval, school setting

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Authors: Christianah Adebimpe Dare, Nelson Oghenebrorhie Elvis

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This study was aimed at analysing the phytochemicals in Chrysophyllum albidum cotyledon extract and their in vitro antioxidant and anti-inflammatory effects. The star apple fruit was bought at Igbona market Osogbo, Osun State, Nigeria. The seed from the fruit was removed and defatted. The residue was exhaustively extracted with methanol. The Chrysophyllum albidum cotyledon methanol extract (CCME) was phytochemically screened, flavonoids and phenol contents, antioxidant and anti-inflammatory assays were carried out on the extract using standard procedures. Phytochemicals analysis revealed the presence of steroids, tannins, flavonoid, saponin, triterpenes, and xanthoproteins. The phenolic concentration, total flavonoids concentration, and total sugar concentration were found to be 26.72 ± 0.048 µgTAE/mg, 23.12 ± 1.92µg of Rutin equivalent (RTE)/mg (10.49 ± 1.12µg of Quercetin equivalent (QE/mg) and 778.38 ± 12.82 µg of glucose/ml, respectively. The extract demonstrated significant inhibitory effect compared with the standards as potent antioxidant with percentage inhibition of DPPH as 38.10 %-39.51 %, lipid peroxidation as 45.85 %-65.85 %; ferric reducing power showed linear correlation to the standard and the anti-inflammatory potential with 22.06 %-26.37 % protection of the human red blood membrane and the percentage inhibition of denaturation of albumin 3.42 %-7.32 %. The study showed that C. albidum cotyledon methanol extract is a potent antioxidant and anti-inflammatory agent to combat oxidative stress and pathological diseases caused by reactive species.

Keywords: albumin denaturation, free radicals, lipid peroxidation, reactive species

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Authors: Rupam Saikia, Ashim Kanti Dey

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Sonapur is an intense hilly region on the border of Assam and Meghalaya lying in North-East India and is very near to a seismic fault named as Dauki besides which makes the region seismically active. Besides, these recently two earthquakes of magnitude 6.7 and 6.9 have struck North-East India in January and April 2016. Also, the slope concerned for this study is adjacent to NH 44 which for a long time has been a sole important connecting link to the states of Manipur and Mizoram along with some parts of Assam and so has been a cause of considerable loss to life and property since past decades as there has been several recorded incidents of landslide, road-blocks, etc. mostly during the rainy season which comes into news. Based on this issue this paper reports a static and dynamic slope stability analysis of Sonapur which has been carried out in MIDAS GTS NX. The slope being highly unreachable due to terrain and thick vegetation in-situ test was not feasible considering the current scope available so disturbed soil sample was collected from the site for the determination of strength parameters. The strength parameters were so determined for varying relative density with further variation in water content. The slopes were analyzed considering plane strain condition for three slope heights of 5 m, 10 m and 20 m which were then further categorized based on slope angles 30, 40, 50, 60, and 70 considering the possible extent of steepness. Initially static analysis under dry state was performed then considering the worst case that can develop during rainy season the slopes were analyzed for fully saturated condition along with partial degree of saturation with an increase in the waterfront. Furthermore, dynamic analysis was performed considering the El-Centro Earthquake which had a magnitude of 6.7 and peak ground acceleration of 0.3569g at 2.14 sec for the slope which were found to be safe during static analysis under both dry and fully saturated condition. Some of the conclusions were slopes with inclination above 40 onwards were found to be highly vulnerable for slopes of height 10 m and above even under dry static condition. Maximum horizontal displacement showed an exponential increase with an increase in inclination from 30 to 70. The vulnerability of the slopes was seen to be further increased during rainy season as even slopes of minimal steepness of 30 for height 20 m was seen to be on the verge of failure. Also, during dynamic analysis slopes safe during static analysis were found to be highly vulnerable. Lastly, as a part of the study a comparative study on Strength Reduction Method (SRM) versus Limit Equilibrium Method (LEM) was also carried out and some of the advantages and disadvantages were figured out.

Keywords: dynamic analysis, factor of safety, slope stability, strength reduction method

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Authors: Bongsik Park, Jae Hyun Park, Jae-Yeol Cho

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Mixed structure, which is a kind of hybrid system, is incorporating steel beam and prestressed concrete beam. Hybrid bridge adopting mixed structure have some merits. Main span length can be made longer by using steel as main span material. In case of cable-stayed bridge having asymmetric span length, negative reaction at side span can be restrained without extra restraining devices by using weight difference between main span material and side span material. However angle of refraction might happen because of rigidity difference between materials and stress concentration also might happen because of abnormal loading transmission at joint in the hybrid bridge. Therefore the joint might be a weak point of the structural system and it needs to pay attention to design of the joint. However, design codes and standards about the joint in the hybrid-bridge have not been established so the joint designs in most of construction cases have been very conservative or followed previous design without extra verification. In this study parametric study using finite element analysis for optimal design of hybrid bridge joint is conducted. Before parametric study, finite element analysis was conducted based on previous experimental data and it is verified that analysis result approximated experimental data. Based on the finite element analysis results, parametric study was conducted. The parameters were selected as those have influences on joint behavior. Based on the parametric study results, optimal design of hybrid bridge joint has been determined.

Keywords: parametric study, optimal design, hybrid bridge, finite element analysis

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Authors: Omar Alhamd, Peter A. Thomas, Trevor J. Greenhough, Annette K. Shrive

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The Pseudomonas syringae species complex includes many plant pathogenic strains with highly specific interactions with varied host species and cultivars. The rapid spread of these bacteria over the last ten years has become a cause for concern. Nanoparticles have previously shown promise in microbiological action. We have therefore investigated in vitro and in vivo the effects of different types and sizes of nanoparticles in order to provide quantitative information about their effect on the bacteria. The effects of several different nanoparticles against several bacteria strains were investigated. The effect of NP on bacterial growth was studied by measuring the optical density, biochemical and nutritional tests, and transmission electron microscopy (TEM) to determine the shape and size of NP. Our results indicate that their effects varied, with either a negative or a positive impact on both bacterial and plant growth. Additionally, the methods of exposure to nanoparticles have a crucial role in accumulation, translocation, growth response and bacterial growth. The results of our studies on the behaviour and effects of nanoparticles in model plants showed. Cerium oxide (CeO₂) and silver (Ag) NP showed significant antibacterial activity against several pathogenic bacteria. It was found that titanium nanoparticles (TiO₂) can have either a negative or a positive impact, according to concentration and size. It is also thought that environmental conditions can have a major influence on bacterial growth. Studies were therefore also carried out under some environmental stress conditions to test bacterial survival and to assess bacterial virulence. All results will be presented including information about the effects of different nanoparticles on Pseudomonas syringae bacteria.

Keywords: plant microbiome, nanoparticles, 16S rRNA gene sequencing, bacterial survival

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Authors: Pius Babuna, Xiaohua Yang, Roberto Xavier Supe Tulcan, Bian Dehui, Mohammed Takase, Bismarck Yelfogle Guba, Chuanliang Han, Doris Abra Awudi, Meishui Lia

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Water inequality, water security, and water governance are fundamental parameters that affect the sustainable use of water resources. Through policy formulation and decision-making, water governance determines both water security and water inequality. Largely, where water inequality exists, water security is undermined through unsustainable water use practices that lead to pollution of water resources, conflicts, hoarding of water, and poor sanitation. Incidentally, the interconnectedness of water governance, water inequality, and water security has not been investigated previously. This study modified the Gini coefficient and used a Logistics Growth of Water Resources (LGWR) Model to access water inequality and water security mathematically, and discussed the connected role of water governance. We tested the validity of both models by calculating the actual water inequality and water security of Ghana. We also discussed the implications of water inequality on water security and the overarching role of water governance. The results show that regional water inequality is widespread in some parts. The Volta region showed the highest water inequality (Gini index of 0.58), while the central region showed the lowest (Gini index of 0.15). Water security is moderately sustainable. The use of water resources is currently stress-free. It was estimated to maintain such status until 2132 ± 18, when Ghana will consume half of the current total water resources of 53.2 billion cubic meters. Effectively, water inequality is a threat to water security, results in poverty, under-development heightens tensions in water use, and causes instability. With proper water governance, water inequality can be eliminated through formulating and implementing approaches that engender equal allocation and sustainable use of water resources.

Keywords: water inequality, water security, water governance, Gini coefficient, moran index, water resources management

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Authors: Jianguo Chen, Fenggang Zang, Yu Yang, Liangang Zheng

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Reactor Pressure Vessel (RPV) is an important security barrier in nuclear power plant. Crack like defects may be produced on RPV during the whole operation lifetime due to the harsh operation condition and irradiation embrittlement. During the severe loss of coolant accident, thermal shock happened as the injection of emergency cooling water into RPV, which results in re-pressurization of the vessel and very high tension stress on the vessel wall, this event called Pressurized Thermal Shock (PTS). Crack on the vessel wall may propagate even penetrate the vessel, so the safety of the RPV would undergo great challenge. Many assumptions in structure integrity evaluation make the result of deterministic fracture mechanics very conservative, which affect the operation lifetime of the plant. Actually, many parameters in the evaluation process, such as fracture toughness and nil-ductility transition temperature, have statistical distribution characteristics. So it is necessary to assess the structural integrity of RPV subjected to PTS event by means of Probabilistic Fracture Mechanics (PFM). Structure integrity evaluation methods of RPV subjected to PTS event are summarized firstly, then evaluation method based on probabilistic fracture mechanics are presented by considering the probabilistic characteristics of material and structure parameters. A comprehensive analysis example is carried out at last. The results show that the probability of crack penetrates through wall increases gradually with the growth of fast neutron irradiation flux. The results give advice for reactor life extension.

Keywords: fracture toughness, integrity evaluation, pressurized thermal shock, probabilistic fracture mechanics, reactor pressure vessel

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Authors: Shazia Farooq Mirza

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The purpose of this study was to explore the challenges faced by visually impaired children and their parents in doing homework assignments using Braille. This study had a quantitative approach and it was descriptive in nature. It took place in 6 public and special private schools of Lahore.177 visually impaired children of grades 4-10 and 153 parents of the visually impaired children were the volunteer participants of this study which were selected through a convenient sampling method. A survey method was adopted for the data collection. And for this purpose 2 self-developed validated questionnaires were used as instruments. The instruments were constructed by exploring the factors and sub-factors from the literature review. Thirty students with visual impairment and 30 parents of the students with visual impairment filled the questionnaires as a pilot study, and it ensured the reliability of the instruments. Data were analyzed using a statistical package of social sciences and it was completely interpreted. Findings revealed that the common challenges faced by the students with visual impairment were Physical Stress, Readiness, Braille Knowledge, Braille Skill and Communications. And the major challenges faced by the parents of the students with visual impairment were the Availability of the helping material, the Availability of the reading material, Braille Knowledge, Braille skills, School and family interactions, Behavior management and the Environment and equipment. Conclusions were drawn on the basis of the major findings. Future suggestions are given in light of the conclusions. This study will be beneficial for the children with visual impairment, the parents of the children with visual impairment, the special education teachers and for the policymakers of the special schools.

Keywords: challenges, visually impaired children, homework, parents, braille

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Authors: Sharifullah Ahmed, Sarwar Jahan Md. Yasin

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Shallow foundations on unimproved soft natural soils can undergo a high consolidation and secondary settlement. For low and medium rise building projects on such soil condition, pile foundation may not be cost effective. In such cases an alternative to pile foundations may be shallow strip footings placed on a double layered improved soil system soil. The upper layer of this system is untreated or cement treated compacted sand and underlying layer is natural soft clay. This system will reduce the settlement to an allowable limit. The current research has been conducted with the settlement of a rigid plane-strain strip footing of 2.5 m width placed on the surface of a soil consisting of an untreated or cement treated sand layer overlying a bed of homogeneous soft clay. The settlement of the mentioned shallow foundation has been studied considering both cases with the thicknesses of the sand layer are 0.3 to 0.9 times the width of footing. The response of the clay layer is assumed as undrained for plastic loading stages and drained during consolidation stages. The response of the sand layer is drained during all loading stages. FEM analysis was done using PLAXIS 2D Version 8.0. A natural clay deposit of 15 m thickness and 18 m width has been modeled using Hardening Soil Model, Soft Soil Model, Soft Soil Creep Model, and upper improvement layer has been modeled using only Hardening Soil Model. The groundwater level is at the top level of the clay deposit that made the system fully saturated. Parametric study has been conducted to determine the effect of thickness, density, cementation of the sand mat and density, shear strength of the soft clay layer on the settlement of strip foundation under the uniformly distributed vertical load of varying value. A set of the chart has been established for designing shallow strip footing on the sand mat over thick, soft clay deposit through obtaining the particular thickness of sand mat for particular subsoil parameter to ensure no punching shear failure and no settlement beyond allowable level. Design guideline in the form of non-dimensional charts has been developed for footing pressure equivalent to medium-rise residential or commercial building foundation with strip footing on soft inorganic Normally Consolidated (NC) soil of Bangladesh having void ratio from 1.0 to 1.45.

Keywords: design charts, ground improvement, PLAXIS 2D, primary and secondary settlement, sand mat, soft clay

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Authors: Nacera Baali, Zahia Belloum, Souad Ameddah, Fadila Benayache, Samir Benayache, Chantal Wrutniak-Cabello

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Allurement of herbs as health beneficial foods and as a source material for the development of new drugs, has led to greater furtherance in the study of herbal medicines during recent years. In the present study, in vitro antioxidant, free radical scavenging capacity, and hepatoprotective activity of butanolic extract from Genista quadriflora Munby (G.quadriflora) were evaluated using established in vitro models such as DPPH radical and hydrogen peroxide radical scavenging activities and antilipidperoxidation ability. Interestingly, the extract showed considerable in vitro antioxidant and free radical scavenging activities in a dose-dependent manner when compared to the standard antioxidant which verified the presence of antioxidant compound in extract tested. The hepatoprotective potential of G.quadriflora extract was also evaluated in male Wistar rats against paracetamol (APAP) induced liver damage. Therapy of G.quadriflora showed the liver protective effect on biochemical and histopathological alterations. Moreover, histological studies also supported the biochemical finding, that is, the maximum improvement in the histoarchitecture of the liver. Results revealed that G.quadriflora extract could protect the liver against APAP-induced oxidative damage by possibly increasing the antioxidant protection mechanism in rats. These findings are of great importance in view of the availability of the plant and its observed possible diverse applications in medicine and nutrition.

Keywords: genista quadriflora munby, antioxidant, liver, paracetamol, oxidative stress

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Authors: Oluwatosin Adetola Arojojoye, Olajumoke Olufunlayo Alao, Philip Odigili

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This study investigated the extent of pollution in Eleyele River in Oyo State, Nigeria by investigating the antioxidant status and malondialdehyde levels (index of lipid peroxidation) in the organs of African Catfish, Clarias gariepinus from the river. Clarias gariepinus weighing between 250g-400g were collected from Eleyele River (a suspected polluted river) and Clarias gariepinus from a clean fish farm (Durantee fisheries) were used as the control. Levels of malondialdehyde, glutathione concentration (GSH) and activities of antioxidant enzymes - superoxide dismutase, catalase and glutathione-S-transferase (GST) were evaluated in the post-mitochondrial fractions of the liver, kidney and gills of the fishes. From the results, there were increases in malondialdehyde level and GSH concentration in the liver, kidney and gills of Clarias gariepinus from Eleyele River when compared with control. Glutathione-S-transferase activity was induced in the liver and kidney of Clarias gariepinus from Eleyele River when compared with control. However, the activity of this enzyme was depleted in the gills of fishes from Eleyele River compared with control. Also there was an induction in SOD activity in the liver of Clarias gariepinus from Eleyele River when compared with control but there was a decrease in the activity of this enzyme in the kidney and gills of fishes from Eleyele River compared with control. Increase in lipid peroxidation and alterations in antioxidant system in Clarias gariepinus from Eleyele River show that the fishes were under oxidative stress. These suggest that the river is polluted probably as a result of industrial, domestic and agricultural wastes frequently discharged into the river. This could pose serious health risks to consumers of water and aquatic organisms from the river.

Keywords: antioxidant, lipid peroxidation, Clarias gariepinus, Eleyele River

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Authors: Fahad Almehmadi, Abdullah Alrajhi, Bader K. Alaslab, Abdullah A. Al Qurashi, Hattan A. Hassani

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Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) is an uncommon, inheritable cardiac disorder characterized by the progressive substitution of cardiac myocytes by fibro-fatty tissues. This pathologic substitution predisposes patients to ventricular arrhythmias and right ventricular failure. The underlying genetic defect predominantly involves genes encoding for desmosome proteins, particularly plakophilin-2 (PKP2). These aberrations lead to impaired cell adhesion, heightening the susceptibility to fibrofatty scarring under conditions of mechanical stress. Primarily, ARVD/C affects the right ventricle, but it can also compromise the left ventricle, potentially leading to biventricular heart failure. Clinical presentations can vary, spanning from asymptomatic individuals to those experiencing palpitations, syncopal episodes, and, in severe instances, sudden cardiac death. The establishment of a diagnostic criterion specifically tailored for ARVD/C significantly aids in its accurate diagnosis. Nevertheless, the task of early diagnosis is complicated by the disease's frequently asymptomatic initial stages, and the overall rarity of ARVD/C cases reported globally. In some cases, as exemplified by the adult female patient in this report, the disease may advance to terminal stages, rendering therapies like Ventricular Tachycardia (VT) ablation ineffective. This case underlines the necessity for increased awareness and understanding of ARVD/C to aid in its early detection and management. Through such efforts, we aim to decrease morbidity and mortality associated with this challenging cardiac disorder.

Keywords: ARVD/C, cardiology, interventional cardiology, cardiac electrophysiology

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Authors: Kjellgren Maria, Lilliehorn Sara, Markström Urban

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This article describes the counselling practice of school social workers (SSWs) with individual children. SSWs work in the school system’s pupil health team, whose primary task is health promotion and prevention. The work of SSWs is about helping children and adolescents who, for various reasons, suffer from mental ill-health, school absenteeism, or stress that make them unable to achieve their intended goals. SSWs preferably meet these children in individual counselling sessions. The aim of this article is to describe and analyse SSWs’ experience of counselling with children and to examine the characteristics of counselling practice. The data collection was conducted through four semi-structured focus group interviews with a total of 22 SSWs in four different regions in Sweden. SSWs provide counselling to children in order to bring about improved feelings or behavioural changes. It can be noted that SSWs put emphasis on both the counselling process and the alliance with the child. The interviews showed a common practice among SSWs regarding the structure of the counselling sessions, with certain steps and approaches being employed. However, the specific interventions differed and were characterised by an eclectic standpoint in which SSWs utilise a broad repertoire of therapeutic schools and techniques. Furthermore, a relational perspective emerged as a most prominent focus for the SSWs by re-emerging throughout the material. We believe that SSWs could benefit from theoretical perspectives on ‘contextual model’ and ‘attachment theory’ as ‘models of the mind’. Being emotionally close to the child and being able to follow their development requires a lot from SSWs, as both professional caregivers and as “safe havens”.

Keywords: school social conselling, school social workers, contextual model, attachment thory

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Authors: Jefto Terzovic, Ana Kontic, Isidora Ilic

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In the proposed design concept, laminated glass and laminated plexiglass, as ”unconventional materials”, are considered as a filling in a steel frame on which they overlap by the intermediate rubber layer, thereby forming a composite assembly. In this way vertical elements of stiffening are formed, capable for reception of seismic force and integrated into the structural system of the building. The applicability of such a system was verified by experiments in laboratory conditions where the experimental models based on laminated glass and laminated plexiglass had been exposed to the cyclic loads that simulate the seismic force. In this way the load capacity of composite assemblies was tested for the effects of dynamic load that was parallel to assembly plane. Thus, the stress intensity to which composite systems might be exposed was determined as well as the range of the structure stiffening referring to the expressed deformation along with the advantages of a particular type of filling compared to the other one. Using specialized software whose operation is based on the finite element method, a computer model of the structure was created and processed in the case study; the same computer model was used for analyzing the problem in the first phase of the design process. The stiffening system based on composite assemblies tested in laboratories is implemented in the computer model. The results of the modal analysis and seismic calculation from the computer model with stiffeners applied showed an efficacy of such a solution, thus rounding the design procedures for aseismic stiffening by using unconventional materials.

Keywords: laminated glass, laminated plexiglass, aseismic stiffening, experiment, laboratory testing, computer model, finite element method

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Authors: Jessica Hemberg, Mikaela Miller

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Unreasonable workload and work-related stress can reduce nurse leaders’ job satisfaction and productivity and can increase absence and burnout. Nurse leaders’ workload in public healthcare settings is relatively unresearched. The aim of this study was to investigate nurse leaders’ perceptions of workload and task distribution with relation to leading work tasks in public healthcare. A qualitative explorative design was used. The data material consisted of texts from interviews with nurse leaders in public healthcare (N=8). The method was inspired by content analysis. The COREQ checklist was used. Informed consent was sought from the participants regarding study participation and the storage and handling of data for research purposes. Six main themes were found: Increased and unreasonable workload, Length of work experience as nurse leader affects perception of workload, Number of staff and staff characteristics affect perception of workload, Versatile and flexible task distribution, Working overtime as a way of managing high workload, and Insufficient time for leadership mission. The workload for nurse leaders in a public healthcare setting was perceived to be unreasonable. Common measures for managing high workload included working overtime, delegating work tasks and organizing more staff resources in the form of additional staff. How nurse leaders perceive their workload was linked to both the number of staff and staff characteristics. These should both be considered equally important when determining staff levels and measuring nurse leaders’ workload. Future research should focus on investigating workload and task distribution from nurses’ perspectives.

Keywords: nurse leaders, workload, task distribution, public healthcare, qualitative

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Authors: Anne Gesare Timu, Megan Sheahan, Andrew Gache Mude, Rupsha Banerjee

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Women headed households are among the most vulnerable to negative climatic shocks and are often left poorer as a result. Credit provision has been recognized as one way of alleviating rural poverty and developing poor rural households’ resilience to shocks. Much has been documented about credit demand in small-holder agriculture settings in Kenya. However, little is known about demand for credit among pastoral women. This paper analyzes the determinants of demand for credit in the pastoral regions of Marsabit District of Northern Kenya. Using a five wave balanced panel data set of 820 households, a double hurdle model is employed to analyze if shocks, financial literacy and risk aversion affect credit demand among female and male headed households differently. The results show that borrowing goods on credit and monetary credit from informal market segments are the most common sources of credit in the study area. The impact of livestock loss and financial literacy on the decision to borrow and how much to borrow vary with gender. While the paper suggests that provision of credit is particularly valuable in the aftermath of a negative shock and more so for female-headed households, it also explores alternatives to the provision of credit where credit access is a constraint. It recommends further understanding of systems and institutions which could enhance access to credit, and particularly during times of stress, to enable households in the study area in particular and Northern Kenya in general to invest, engage in meaningful development and growth, and be resilient to persistent shocks.

Keywords: female headed households, pastoralism, rural financing, double hurdle model

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Authors: Teng lin, Li Yuxing, Han Hui, Zhao Pengfei, Zhang Datong

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With the development of carbon capture and storage (CCS), the flow assurance of CO2 transportation becomes more important, particularly for supercritical CO2 pipelines. The relieving system using the choke valve is applied to control the pressure in CO2 pipeline. However, the temperature of fluid would drop rapidly because of Joule-Thomson cooling (JTC), which may cause solid CO2 form and block the pipe. In this paper, a Computational Fluid Dynamic (CFD) model, using the modified Lagrangian method, Reynold's Stress Transport model (RSM) for turbulence and stochastic tracking model (STM) for particle trajectory, was developed to predict the deposition characteristic of solid carbon dioxide. The model predictions were in good agreement with the experiment data published in the literature. It can be observed that the particle distribution affected the deposition behavior. In the region of the sudden expansion, the smaller particles accumulated tightly on the wall were dominant for pipe blockage. On the contrary, the size of solid CO2 particles deposited near the outlet usually was bigger and the stacked structure was looser. According to the calculation results, the movement of the particles can be regarded as the main four types: turbulent motion close to the sudden expansion structure, balanced motion at sudden expansion-middle region, inertial motion near the outlet and the escape. Furthermore the particle deposits accumulated primarily in the sudden expansion region, reattachment region and outlet region because of the four type of motion. Also the Stokes number had an effect on the deposition ratio and it is recommended for Stokes number to avoid 3-8St.

Keywords: carbon capture and storage, carbon dioxide pipeline, gas-particle flow, deposition

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Authors: Vladimir Vinnikov

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The paper proposes a model of an inhomogeneous rock mass with initially random distribution of microcracks on mineral grain boundaries. It describes the behavior of cracks in a medium under the effect of thermal field, the medium heated instantaneously to a predetermined temperature. Crack growth occurs according to the concept of fracture mechanics provided that the stress intensity factor K exceeds the critical value of Kc. The modeling of thermally induced acoustic emission memory effects is based on the assumption that every event of crack nucleation or crack growth caused by heating is accompanied with a single acoustic emission event. Parameters of the thermally induced acoustic emission memory effect produced by cyclic heating and cooling (with the temperature amplitude increasing from cycle to cycle) were calculated for several rock texture types (massive, banded, and disseminated). The study substantiates the adaptation of the proposed model to humidity interference with the thermally induced acoustic emission memory effect. The influence of humidity on the thermally induced acoustic emission memory effect in quasi-homogeneous and banded rocks is estimated. It is shown that such modeling allows the structure and texture of rocks to be taken into account and the influence of interference factors on the distinctness of the thermally induced acoustic emission memory effect to be estimated. The numerical modeling can be used to obtain information about the thermal impacts on rocks in the past and determine the degree of rock disturbance by means of non-destructive testing.

Keywords: crack growth, cyclic heating and cooling, rock texture, thermo acoustic emission memory effect

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Authors: Chih-Hsien Chen, Yi-Hung Ho, Chih-Wei Wang, Chih-Wei Chang, Yen-Nien Chen, Chih-Han Chang, Chun-Ting Li

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Laminotomy is a spinal decompression surgery compatible with a minimally invasive approach. However, the unilateral laminotomy for bilateral side decompression leads to more perioperative complications than the bilateral laminotomy. Although the unilateral laminotomy removes the least bone tissue among the spinal decompression surgeries, the difference of spinal stability between unilateral and bilateral laminotomy and laminectomy is rarely investigated. This study aims to compare the biomechanical effects of unilateral and bilateral laminotomy and laminectomy on the lumbar spine by finite element (FE) simulation. A three-dimensional FE model of the lumbar spine (L1–L5) was constructed with the vertebral body, discs, and ligaments, as well as the sacrum was constructed. Three different surgical methods, namely unilateral laminotomy, bilateral laminotomy and laminectomy, at L3–L4 and L4–L5 were considered. Partial pedicle and entire ligamentum flavum were removed to simulate bilateral decompression in laminotomy. The entire lamina and spinal processes from the lower L3 to upper L5 were detached in the laminectomy model. Then, four kinds of loadings, namely flexion, extension, lateral bending and rotation, were applied on the lumbar with various decompression conditions. The results indicated that the bilateral and unilateral laminotomy both increased the range of motion (ROM) compared with intact lumbar, while the laminectomy increased more ROM than both laminotomy did. The difference of ROM between the bilateral and unilateral laminotomy was very minor. Furthermore, bilateral laminotomy demonstrated similar poster element stress with unilateral laminotomy. Unilateral and bilateral laminotomy are equally suggested to bilateral decompression of lumbar spine with minimally invasive technique because limited effect was aroused due to more bone remove in the bilateral laminotomy on the lumbar stability. Furthermore, laminectomy is the last option for lumbar decompression.

Keywords: minimally invasive technique, lumbar decompression, laminotomy, laminectomy, finite element method

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Authors: Neha Singh, Anuj Ranjan, Tanu Jindal

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Over the last decade, the exponential growth of mobile communication has been accompanied by a parallel increase in density of electromagnetic fields (EMF). The continued expansion of mobile phone usage raises important questions as EMF, especially radio frequency (RF), have long been suspected of having biological effects. In the present experiments, we studied the effects of RF-EMF on cell death (apoptosis) and DNA damage of a well- tested biological model, Drosophila melanogaster exposed to 2400 MHz frequency for different time duration i.e. 2 hrs, 4 hrs, 6 hrs,8 hrs, 10 hrs, and 12 hrs each day for five continuous days in ambient temperature and humidity conditions inside an exposure chamber. The flies were grouped into control, sham-exposed, and exposed with 100 flies in each group. In this study, well-known techniques like Comet Assay and TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) Assay were used to detect DNA damage and for apoptosis studies, respectively. Experiments results showed DNA damage in the brain cells of Drosophila which increases as the duration of exposure increases when observed under the observed when we compared results of control, sham-exposed, and exposed group which indicates that EMF radiation-induced stress in the organism that leads to DNA damage and cell death. The process of apoptosis and mutation follows similar pathway for all eukaryotic cells; therefore, studying apoptosis and genotoxicity in Drosophila makes similar relevance for human beings as well.

Keywords: cell death, apoptosis, Comet Assay, DNA damage, Drosophila, electromagnetic fields, EMF, radio frequency, RF, TUNEL assay

Procedia PDF Downloads 145