Search results for: source of stress

Authors: M. Szechynska-Hebda, M. Sobczak, E. Rozanska, J. Troczynska, Z. Banaszak, N. Hordyńska, M. Dyda, M. Wedzony

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Chloroplasts, as essential organelles for photosynthesis, play a critical role in plant development. However, disturbances in the proper functioning of chloroplasts, in the extreme case manifesting as albinism of tissues and whole plants, are a phenomenon often occurring in conditions deviating from natural (e.g., in vitro cultures applied in breeding programs). Using whole-transcriptome analysis (RNA-Seq) together with light, fluorescent and electron microscopy, it was shown, that development of chloroplasts and formation of green or albino plants in the androgenesis process are genotype-dependent; however, they could be modulated by sub-optimal temperature treatment. The reprogramming of the microspore development from gametophytic to sporophytic, and then regeneration of green plant can be positively regulated by cold stress (4 ⁰C). A high temperature stress (32 ⁰C) can induce androgenesis, but it is a factor negatively influencing green plant regeneration (promoting albinism). A similar effect on microspores, androgenesis, and subsequent chloroplast formation, is elicited as a result of postponing the date of spike collection from spring to summer in field conditions (natural temperature rise). It is determined in both environmental or genotypic manner. The delay of the sowing date (environmental effect) or growing of late genotypes (genotypic effect) result in spike maturation at higher temperatures and significantly enhance albino plant formation in androgenesis process. Such a temperature system (4 ⁰C vs. 32 ⁰C) was used to study the chloroplast biogenesis process in wheat and triticale. It was shown, that efficiency of physiological processes differentiates microspore development during cold reprograming in genotypes susceptible and resistant to androgenesis. Moreover, a great variation in developmental stages of the microspores in one anther is observed for susceptible genotypes. Microspores that are more physiologically active under cold conditions can activate signaling pathways and processes, which provide an appropriate supply of metabolites to cell compartments. This, in turn, fully correlates with the genotype-dependent efficiency of chloroplast formation (or different types of plastid) at particular steps of androgenesis. The effect obtained after applying a high temperature stress is different. High temperature causes a significant acceleration of microspore development and less variation in developmental stages at the end of the treatment. Therefore, the developmental diversity of the microspores in one anther seems to be a critical factor for subsequent cell and chloroplast differentiation. The work was financed by Ministry of Agriculture and Rural Development within Program: 'Biological Progress in Plant Production', project no HOR.hn.802.15.2018

Keywords: androgenesis, chloroplast biogenesis, temperature stress, wheat

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Authors: Yantao Li, Jun Zheng

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Food poison caused by consumption of contaminated food, especially seafood, is one of most serious public health threats worldwide. Vibrio parahaemolyticus is emerging bacterial pathogen and the leading cause of human gastroenteritis associated with food poison, especially in the southern coastal region of China. To successfully cause disease in host, bacterial pathogens need to overcome the host-derived stresses encountered during infection. One of the toxic chemical species elaborated by the host is nitric oxide (NO). NO is generated by acidified nitrite in the stomach and by enzymes of the inducible NO synthase (iNOS) in the host cell, and is toxic to bacteria. Bacterial pathogens have evolved some mechanisms to battle with this toxic stress. Such mechanisms include genes to sense NO produced from immune system and activate others to detoxify NO toxicity, and genes to repair the damage caused by toxic reactive nitrogen species (RNS) generated during NO toxic stress. However, little is known about the NO resistance in V. parahaemolyticus. In this study, a transposon coupled with next generation sequencing (Tn-seq) technology will be utilized to identify genes for NO resistance in V. parahaemolyticus. Our strategy will include construction the saturating transposon insertion library, transposon library challenging with NO, next generation sequencing (NGS), bioinformatics analysis and verification of the identified genes in vitro and in vivo.

Keywords: vibrio parahaemolyticus, nitric oxide, tn-seq, virulence

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Authors: Oday Al-Mamoori, J. Enrique Martinez-Rueda

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'C' shape yielding devices (C-devices) are effective tools for introducing supplemental sources of energy dissipation by hysteresis. Studies have shown that C-devices made of mild steel can be successfully applied as integral parts of seismic retrofitting schemes. However, explicit modelling of these devices can become cumbersome, expensive and time consuming. The device under study in this article has been previously used in non-invasive dissipative bracing for seismic retrofitting. The device is cut from a mild steel plate and has an overall shape that resembles that of a rectangular portal frame with circular interior corner transitions to avoid stress concentration and to control the extension of the dissipative region of the device. A number of inelastic finite element (FE) analyses using either inelastic 2D plane stress elements or inelastic fibre frame elements are reported and used to calibrate a 1D equivalent inelastic spring model that effectively reproduces the cyclic response of the device. The more elaborate FE model accounts for the frictional forces developed between the steel plate and the bolts used to connect the C-device to structural members. FE results also allow the visualization of the inelastic regions of the device where energy dissipation is expected to occur. FE analysis results are in a good agreement with experimental observations.

Keywords: C-device, equivalent nonlinear spring, FE analyses, reversed cyclic tests

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Authors: Anis Eloud, Ben Salah Nahla, Sayed Chehaibi

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In order to improve and develop the Tunisian agriculture, the government has encouraged the introduction of modern technologies and has also promoted the adoption of innovative practices cultures. Indeed, the extensive use of mechanization can increase crop productivity but its inadequate application also has a negative impact on the ground caused by the phenomenon of compaction. Which will cause the loss of soil fertility and increased production costs. This problem is accentuated with increase the stress on contact wheel / ground. For this reason, the objective of this study is to simulate the footprint of the ground contact / tire two types of tractor after their passage. The method of this work is based on a simulation including passages from two different tractors on soil with similar characteristics. Simulation parameters were based on the choice of two tractors masses of 6500 kg and 4400 kg of soil and sandy loam in nature. The analysis was performed using specific software. The main results showed that the heaviest tractor caused a constraint wheel / rear floor exceeding 100 kPa. For cons, the second tractor has caused stress wheel / rear floor of 50 kPa. The comparison of the two results showed that 6500 kg tractor made a serious and excessive compaction which generated a negative impact on soil quality and crop yields.

Keywords: compaction, soil, resistance to penetration, crop yields

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Authors: Salman Abdul Majeed, Vidur Solanki, Ruqiya Shama Tareen

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BACKGROUND: The COVID-19 pandemic has affected the way of living as we have known for all strata of society. While disease containment measures imposed by governmental agencies have been instrumental in controlling the spread of the virus, it has had profound collateral impacts on all populations. However, the disruption caused in the lives of one segment of population has been far more damaging than most others: the emotional wellbeing of our child and adolescent populations. This impact was even more pronounced in children who already suffered from neurodevelopmental or psychiatric disorders. In particular, school closures have not only led to profound social isolation, but also negative impacts on normal developmental opportunities and interruptions in mental health services obtained through school systems. It is too soon to understand the full impacts of quarantine, isolation, stress of social detachment and fear of pandemic, but we have started to see the devastating impact on C&A already. This review intends to shed light on the current understanding of psychiatric wellbeing of C&A during COVID-19 pandemic. METHOD: Literature search utilizing key words COVID-19 and children, quarantine and children, social isolation, Loneliness, pandemic stress and children, and mental health of children, disease containment measures was carried out. Over 200 articles were identified, out of which 81 articles were included in this review article. RESULTS: The disruption caused by COVID-19 in the lives of C&A is much more damaging and its impact is far reaching. The C&A ED visits for possible suicide attempts have jumped to 22.3% in 2020 and 39.1% during 2021. One study utilizing T1-weighted structural images, computed the thickness of cortical and subcortical structures including amygdala, hippocampus, and nucleus accumbens. The Peri-COVID group showed reduced cortical and subcortical thickness and more advanced brain aging compared to pre pandemic studies. CONCLUSION: Mental health resources for C&A remain under funded, neglected, and inaccessible to population that needs it most. Children with ongoing mental health disorders were impacted worst, along with those with predisposed biopsychosocial risk factors.

Keywords: COVID-19 and children, quarantine and children, social isolation, Loneliness, pandemic stress and children, disease containment measures, mental health of children

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Authors: Rajkamal Kumar, Sudhir Mishra

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The connections between various elements of concrete structures play a vital role in determining the durability of structures. These connections produce discontinuities and to ensure the monolithic behavior of structures, these connections should be carefully designed. The connections between concrete layers may occur in various situations such as structure repairing and rehabilitation or construction of huge structures with cast-in-situ or pre-cast elements, etc. Bond strength at the interface of these concrete layers should be able to prevent the progressive slip from taking place and it should also ensure satisfactory performance of the structure. Different approaches to enhance the bond strength at interface have been a major area of research. Nowadays, micro-concrete is getting popular as a repair material. Under this ambit, this paper aims to present the experimental results of connections between concrete layers of different age with artificial indentation at interface with two types of repair material: Concrete with same parent concrete composition and ready-mix mortar (micro-concrete), artificial indentations (grooves and holes) were made on the old layer of concrete to increase the bond strength. Curing plays an important role in determining the bond strength. Optimum duration for curing have also been discussed for each type of repair material. Different types of failure patterns have also been mentioned.

Keywords: adhesion, cohesion, compressive stress, micro-concrete, shear stress, slant shear test

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Authors: V. S. Manivasagam, R. Nagarajan

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Modeling the soil, water and crop growth interactions are attaining major importance, considering the future climate change and water availability for agriculture to meet the growing food demand. Progress in understanding the crop growth response during water stress period through crop modeling approach provides an opportunity for improving and sustaining the future agriculture water use efficiency. An attempt has been made to evaluate the potential use of crop modeling approach for assessing the minimal supplementary irrigation requirement for crop growth during water limited condition and its practical significance in sustainable improvement of crop yield and water productivity. Among the numerous crop models, water driven-AquaCrop model has been chosen for the present study considering the modeling approach and water stress impact on yield simulation. The study has been evaluated in rainfed maize grown area of semi-arid Shanmuganadi watershed (a tributary of the Cauvery river system) located in southern India during the rabi cropping season (October-February). In addition to actual rainfed maize growth simulation, irrigated maize scenarios were simulated for assessing the supplementary irrigation requirement during water shortage condition for the period 2012-2015. The simulation results for rainfed maize have shown that the average maize yield of 0.5-2 t ha-1 was observed during deficit monsoon season (<350 mm) whereas 5.3 t ha-1 was noticed during sufficient monsoonal period (>350 mm). Scenario results for irrigated maize simulation during deficit monsoonal period has revealed that 150-200 mm of supplementary irrigation has ensured the 5.8 t ha-1 of irrigated maize yield. Thus, study results clearly portrayed that minimal application of supplementary irrigation during the critical growth period along with the deficit rainfall has increased the crop water productivity from 1.07 to 2.59 kg m-3 for major soil types. Overall, AquaCrop is found to be very effective for the sustainable irrigation assessment considering the model simplicity and minimal inputs requirement.

Keywords: AquaCrop, crop modeling, rainfed maize, water stress

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Authors: Tabinda Sadiq, Tehmina Ashfaq Qazi, Hoor Shumail

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Recently, the advent of emerging technology has created an emerging generation of restaurant marketing. It explores the aspects that influence customers’ decision-making process in selecting a restaurant after reading food bloggers' reviews online. The motivation behind this research is to investigate the correlation between the credibility of the source and their attitude toward restaurant visits. The researcher collected the data by distributing a survey questionnaire through google forms by employing the Source credibility theory. Non- probability purposive sampling technique was used to collect data. The questionnaire used a predeveloped and validated scale by Ohanian to measure the relationship. Also, the researcher collected data from 250 respondents in order to investigate the influence of food bloggers on Gen Z's decision-making process. SPSS statistical version 26 was used for statistical testing and analyzing the data. The findings of the survey revealed that there is a moderate positive correlation between the variables. So, it can be analyzed that food bloggers do have an impact on Generation Z's decision making process.

Keywords: credibility, decision making, food bloggers, generation z, e-wom

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Authors: Amit Kumar Happy

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This paper is motivated by the importance of multi-sensor image fusion with a specific focus on infrared (IR) and visual image (VI) fusion for various applications, including military reconnaissance. Image fusion can be defined as the process of combining two or more source images into a single composite image with extended information content that improves visual perception or feature extraction. These images can be from different modalities like visible camera & IR thermal imager. While visible images are captured by reflected radiations in the visible spectrum, the thermal images are formed from thermal radiation (infrared) that may be reflected or self-emitted. A digital color camera captures the visible source image, and a thermal infrared camera acquires the thermal source image. In this paper, some image fusion algorithms based upon multi-scale transform (MST) and region-based selection rule with consistency verification have been proposed and presented. This research includes the implementation of the proposed image fusion algorithm in MATLAB along with a comparative analysis to decide the optimum number of levels for MST and the coefficient fusion rule. The results are presented, and several commonly used evaluation metrics are used to assess the suggested method's validity. Experiments show that the proposed approach is capable of producing good fusion results. While deploying our image fusion algorithm approaches, we observe several challenges from the popular image fusion methods. While high computational cost and complex processing steps of image fusion algorithms provide accurate fused results, they also make it hard to become deployed in systems and applications that require a real-time operation, high flexibility, and low computation ability. So, the methods presented in this paper offer good results with minimum time complexity.

Keywords: image fusion, IR thermal imager, multi-sensor, multi-scale transform

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Authors: S. MacDougall-Davis, S. Wysling, R. Willmore

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Background: The application of good non-technical skills, also known as crew resource management (CRM), is central to the delivery of safe, effective healthcare. The authors have been running remote trauma courses for over 10 years, primarily focussing on developing participants’ CRM in time-critical, high-stress clinical situations. The course has undergone an iterative process over the past 10 years. We employ a number of experiential learning techniques for improving CRM, including small group workshops, military command tasks, high fidelity simulations with reflective debriefs, and a ‘flipped classroom’, where participants are asked to create their own simulations and assess and debrief their colleagues’ CRM. We created a randomised simulation study to assess the impact of our course on UK medical students’ CRM, both at an individual and a teams level. Methods: Sixteen students took part. Four clinical scenarios were devised, designed to be of similar urgency and complexity. Professional moulage effects and experienced clinical actors were used to increase fidelity and to further simulate high-stress environments. Participants were block randomised into teams of 4; each team was randomly assigned to one pre-course simulation. They then underwent our 5 day remote trauma CRM course. Post-course, students were re-randomised into four new teams; each was randomly assigned to a post-course simulation. All simulations were videoed. The footage was reviewed by two independent CRM-trained assessors, who were blinded to the before/after the status of the simulations. Assessors used the internationally validated team emergency assessment measure (TEAM) to evaluate key areas of team performance, as well as a global outcome rating. Prior to the study, assessors had scored two unrelated scenarios using the same assessment tool, demonstrating 89% concordance. Participants also completed pre- and post-course questionnaires. Likert scales were used to rate individuals’ perceived NTS ability and their confidence to work in a team in time-critical, high-stress situations. Results: Following participation in the course, a significant improvement in CRM was observed in all areas of team performance. Furthermore, the global outcome rating for team performance was markedly improved (40-70%; mean 55%), thus demonstrating an impact at Level 4 of Kirkpatrick’s hierarchy. At an individual level, participants’ self-perceived CRM improved markedly after the course (35-70% absolute improvement; mean 55%), as did their confidence to work in a team in high-stress situations. Conclusion: Our study demonstrates that with a short, cost-effective course, using easily reproducible teaching sessions, it is possible to significantly improve participants’ CRM skills, both at an individual and, perhaps more importantly, at a teams level. The successful functioning of multi-disciplinary teams is vital in a healthcare setting, particularly in high-stress, time-critical situations. Good CRM is of paramount importance in these scenarios. The authors believe that these concepts should be introduced from the earliest stages of medical education, thus promoting a culture of effective CRM and embedding an early appreciation of the importance of these skills in enabling safe and effective healthcare.

Keywords: crew resource management, non-technical skills, training, simulation

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Authors: Alessio Mastrorillo, Giuseppe Silvi, Francesco Scagliola

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In this work, we introduce an Ambisonics decoder with an implementation of the C-format, also called Super Stereo. This format is an alternative to conventional stereo and binaural decoding. Unlike those, this format conveys audio information from the horizontal plane and works with stereo speakers and headphones. The two C-format channels can also return a reconstructed planar B-format. This work provides an open-source implementation for this format. We implement an all-pass filter for signal quadrature, as required by the decoding equations. This filter works with six Biquads in a cascade configuration, with values for control frequency and quality factor discovered experimentally. The phase response of the filter delivers a small error in the 20-14.000Hz range. The decoder has been tested with audio sources up to 192kHz sample rate, returning pristine sound quality and detailed stereo image. It has been included in the Envelop for Live suite and is available as an open-source repository. This decoder has applications in Virtual Reality and 360° audio productions, music composition, and online streaming.

Keywords: ambisonics, UHJ, quadrature filter, virtual reality, Gerzon, decoder, stereo, binaural, biquad

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Authors: Kayla Marie Sarte

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This study sought to describe mother tongue-based classes in the light of classroom interactional discourse using the Sinclair and Coulthard model. It specifically identified the exchanges, grouped into Teaching and Boundary types; moves, coded as Opening, Answering and Feedback; and the occurrence of the 13 acts (Bid, Cue, Nominate, Reply, React, Acknowledge, Clue, Accept, Evaluate, Loop, Comment, Starter, Conclusion, Aside and Silent Stress) in the classroom, and determined what these reveal about the teaching and learning processes in the MTB classroom. Being a qualitative study, using the Single Collective Case Within-Site (embedded) design, varied data collection procedures such as non-participant observations, audio-recordings and transcription of MTB classes, and semi-structured interviews were utilized. The results revealed the presence of all the codes in the model (except for the silent stress) which also implied that the Hiligaynon mother tongue-based class was eclectic, cultural and communicative, and had a healthy, analytical and focused environment which aligned with the aims of MTB-MLE, and affirmed the purported benefits of mother tongue teaching. Through the study, gaps in the mother tongue teaching and learning were also identified which involved the difficulty of children in memorizing Hiligaynon terms expressed in English in their homes and in the communities.

Keywords: discourse analysis, language teaching and learning, mother tongue-based education, multilingualism

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Authors: Harshita Raj, Joydeep Ghosh, Rakesh L. Tanna, Prabal K. Chattopadhyay, K. A. Jadeja, Sharvil Patel, Kaushal M. Patel, Narendra C. Patel, S. B. Bhatt, V. K. Panchal, Chhaya Chavda, C. N. Gupta, D. Raju, S. K. Jha, J. Raval, S. Joisa, S. Purohit, C. V. S. Rao, P. K. Atrey, Umesh Nagora, R. Manchanda, M. B. Chowdhuri, Nilam Ramaiya, S. Banerjee, Y. C. Saxena

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Efficient gas fueling is a critical aspect that needs to be mastered in order to maintain plasma density, to carry out fusion. This requires a fair understanding of fuel recycling in order to optimize the gas fueling. In Aditya tokamak, multiple gas puffs are used in a precise and controlled manner, for hydrogen fueling during the flat top of plasma discharge which has been instrumental in achieving discharges with enhanced density as well as energy confinement time. Following each gas puff, we observe peaks in temporal profile of Hα emission, Soft X-ray (SXR) and chord averaged electron density in a number of discharges, indicating efficient gas fueling. Interestingly, Hα temporal profile exhibited an additional peak following the peak corresponding to each gas puff. These additional peak Hα appeared in between the two gas puffs, indicating the presence of a secondary hydrogen source apart from the gas puffs. A thorough investigation revealed that these secondary Hα peaks coincide with Hard X- ray bursts which come from the interaction of runaway electrons with vessel limiters. This leads to consider that the runaway electrons (REs), which hit the wall, in turn, bring out the absorbed hydrogen and oxygen from the wall and makes the interaction of REs with limiter a secondary hydrogen source. These observations suggest that runaway electron induced recycling should also be included in recycling particle source in the particle balance calculations in tokamaks. Observation of two Hα peaks associated with one gas puff and their roles in enhancing and maintaining plasma density in Aditya tokamak will be discussed in this paper.

Keywords: fusion, gas fueling, recycling, Tokamak, Aditya

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Authors: Mohammed Qutishat, Loai Abu Sharour, Kholoud Al-Damery, Ibtisam Al Harthy, Sulaiman Al-Sabei

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Background: The 2019 coronavirus outbreak (COVID-19) has been declared a pandemic and has greatly affected both patients and healthcare workers. This study was conducted to explore the extent of posttraumatic stress disorder (PTSD) experiences among nurses as a result of the COVID-19 pandemic in Jordan. Method: This study used a cross-sectional study design with a convenience sampling approach. A sample of 259 participants completed the study questionnaires, including a sociodemographic questionnaire and the posttraumatic stress disorder checklist for DSM‐5, between May and July 2020. Result: The prevalence of PTSD among the study participants was 37.1%. The majority of study participants who exhibited PTSD symptoms presented the lowest level of PTSD (17%). The results indicated significant differences in overall COVID-19-related PTSD according to the participant’s age (F = 14.750, P = .000), gender (F = 30.340, P = .000), level of education (F = 51.983, P =.000), years of experience (F = 52.33, P = .000), place of work (F = 19.593, P = .000), and working position (F = 11.597, P = .000), as determined by one-way ANOVA. Conclusion: Nurses must be qualified and accredited to cope with reported PTSD cases and their consequences in relation to COVID-19 outbreaks. Close collaboration with a multidisciplinary team is required to recognise, manage, and encourage safety literacy among health care professionals and individuals diagnosed with or suspected of PTSD due to COVID-19 outbreaks or any other viral outbreaks.

Keywords: PTSD, nursing, coronavirus, pandemic, infectious disease

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Authors: Karthick Gopalan, Selvamohan Thankiah

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Biosurfactants are lipid compounds produced by microbes, which are amphipathic molecules consisting of hydrophophic and hydrophilic domains. In the present investigation, ten bacterial strains were isolated from petroleum oil contaminated sites near petrol bunk. Oil collapsing test, haemolytic activity were used as a criteria for primary isolation of biosurfactant producing bacteria. In this study, all the bacterial strains gave positive results. Among the ten strains, two were observed as good biosurfactant producers, they utilize the diesel as a sole carbon source. Optimization of biosurfactant producing bacteria isolated from petroleum oil contaminated sites was carried out using different parameters such as, temperature (20ºC, 25ºC, 30ºC, 37ºC and 45ºC), pH (5,6,7,8 & 9) and nitrogen sources (ammonium chloride, ammonium carbonate and sodium nitrate). Biosurfactants produced by bacteria were extracted, dried and quantified. As a result of optimization of parameters the suitable values for the production of more amount of biosurfactant by the isolated bacterial species was observed as 30ºC (0.543 gm/lt) in the pH 7 (0.537 gm/lt) with ammonium nitrate (0.431 gm/lt) as sole carbon source.

Keywords: isolation and identification, biosurfactant, microorganism, bioaugmentation

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Authors: Xing Lyu

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Multimodal metaphor promotes the further development and refinement of multimodal discourse study. Cultural aspects matter a lot not only in creating but also in comprehending multimodal metaphor. By analyzing the target domain and the source domain in 10 public service advertisements of China and Germany about environmental protection, this paper compares the source when the target is alike in each multimodal metaphor in order to seek similarities and differences across cultures. The findings are as follows: first, the multimodal metaphors center around three major topics: the earth crisis, consequences of environmental damage, and appeal for environmental protection; second, the multimodal metaphors mainly grounded in three universal conceptual metaphors which focused on high level is up; earth is mother and all lives are precious. However, there are five Chinese culture-specific multimodal metaphors which are not discovered in Germany ads: east is high leve; a purposeful life is a journey; a nation is a person; good is clean, and water is mother. Since metaphors are excellent instruments on studying ideology, this study can be helpful on intercultural/cross-cultural communication.

Keywords: multimodal metaphor, cultural aspects, public service advertising, cross-cultural communication

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Authors: Ewon Kaliyadasa, U. L. B. Jayasinghe, S. E. Peiris

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Ashwagandha (Withania sominifera Duanal) is an important medicinal herb belongs to family Solanaceae. This plant has raised its popularity after discovering anti stress and sex stimulating properties that mainly due to the presence of biologically active alkaloid compounds. Therefore it is vital to adapt to a proper agro technological package that ensure optimum growth of ashwagandha to obtain the finest quality without degrading pharmacologically active constituents. Organic and inorganic fertilizer mixtures were combined with direct seeding and transplanting as four different treatments in this study. Tuber fresh and dry weights were recorded up to twelve months starting from two months after sowing (MAS) while shoot height, root length, number of leaves, shoot fresh and dry weights and root: shoot ratio up to 6MAS. Results revealed that growth of ashwagandha was not affected significantly by method of planting or type of fertilizer or its combinations during most of the harvests. However, tubers harvested at 6MAS recorded the highest dry tuber weight per plant in all four treatments compared to early harvests where two direct seeded treatments are the best. Chemical comparison of these two treatments, direct seeding coupled with organic and inorganic fertilizer shown that direct seeding with organic treatment recorded the highest values for alkaloid and withaferine A content with lower percentage of fiber. Further these values are in concurring with the values of commercially available tuber samples. Having considered all facts, 6MAS can be recommended as the best harvesting stage to obtain high quality tubers of ashwagandha under local conditions.

Keywords: alkaloids, direct seeding, dry tuber weight, inorganic fertilizer, organic fertilizer, transplanting, withaferine a

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Authors: Grmay Kassa Brhane, Hailemariam Siyum Mekonen

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This study was designed to identify the hydrogeochemical and anthropogenic processes controlling the evaluation of groundwater chemistry in the Ellala catchment which covers about 296.5 km2 areal extent. The chemical analysis revealed that the major ions in the groundwater are Ca2+, Mg2+, Na+, and K+ (cations) and HCO3-, PO43-, Cl-, NO3-, and SO42-(anions). Most of the groundwater samples (68.42%) revealed that the groundwater in the catchment is non-alkaline. In addition to the contribution of aquifer material, the solid materials and liquid wastes discharged from different sources can be the main sources of pH and EC in the groundwater. It is observed that the EC of the groundwater is fairly correlated with the DTS. This indicates that high mineralized water is more conductor than water with low concentration. The degree of salinity of the groundwater increases along the groundwater flow path from East to West; then, areas surrounding Mekelle City are highly saline due to the liquid and solid wastes discharged from the city and the industries. The groundwater facies in the catchment are predominated with calcium, magnesium, and bicarbonate which are labeled as Ca-Mg-HCO3 and Mg-Ca-HCO3. The main geochemical process controlling the evolution of the groundwater chemistry in the catchment is rock-water interaction, particularly carbonate dissolution. Due to the clay layer in the aquifer, the reverse is ion exchange. Non-significant silicate weathering and halite dissolution also contribute to the evolution of groundwater chemistry in the catchment. The groundwater in the catchment is dominated by the meteoritic origin although it needs further groundwater chemistry study with isotope dating analysis. The groundwater is under-saturated with calcite, dolomite, and aragonite minerals; hence, the more these minerals encounter the groundwater, the more the minerals dissolve. The main source of calcium and magnesium in groundwater is the dissolution of carbonate minerals (calcite and dolomite) since carbonate rocks are the dominant aquifer materials in the catchment. In addition to this, the weathering of dolerite rock is a possible source of magnesium ions. The relatively higher concentration of sodium over chloride indicates that the source of sodium-ion is reverse ion exchange and/or weathering of sodium-bearing materials, such as shale and dolerite rather than halite dissolution. High concentration of phosphate, nitrate, and chloride in the groundwater is the main anthropogenic source that needs treatment, quality control, and management in the catchment. From the Base Exchange Index Analysis, it is possible to understand that, in the catchment, the groundwater is dominated by the meteoritic origin, although it needs further groundwater chemistry study with isotope dating analysis.

Keywords: Ellala catchment, factor, chemistry, geochemical, groundwater

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Authors: Noshaba Dilbar, Maria Jabbar

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Medicinal plants are considered to be the richest source of drug discovery. The main cause of medicinal properties of plants is the presence of bioactive compounds in them. Phytochemical screening is the valuable process that detects bioactive compounds(secondary metabolites) in plants. The present study was carried out to determine phytochemical profile and ethnobotanical importance of Capparidaceae species. ( Capparis spinosa and Dipterygium glaucum). The selection of plants was made on basis of traditional knowledge of their usage in ayurvedic medicines. Different type of solvents(ethanol, methanol, chloroform, benzene and petroleum ether) were used to make extracts of dry and fresh plants. Phytochemical screening was made by using various standard techniques. Results reveal the presence of large range of bioactive compounds i.e alakloids, saponins, flavonoids, terpenoids, glycosides, phenols and steroids. Methanol, petroleum ether and chloroform extracts showed high extractability of bioactive compounds. The results obtained ensure these plants a reliable source of pharmacological industry and can be used in making of various biological friendly drugs.

Keywords: bioactive compounds, Capparidaceae, phytochemical screening, secondary metabolites

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Authors: Ayeshmanthe Rathnayake, Siew Goh, Carmel Fenton, Ashutosh Hardikar

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Post-Operative Atrial Fibrillation (POAF) is the most frequent complication of cardiac surgery and is associated with reduced survival, increased rates of cognitive changes and cerebrovascular accident, heart failure, renal dysfunction, infection and length of stay, and hospital costs. Cardiac tamponade, although less common, carries high morbidity and mortality. Shed mediastinal blood in the pericardial space is a major source of intrapericardial oxidative stress and inflammation that triggers POAF. The utilisation of a left posterior pericardiotomy aims to shunt blood from the pericardium into the pleural space and have a role in the prevention of POAF as well as cardiac tamponade. 2118 patients had undergone isolated Coronary Artery Bypass Graft (CABG) at Royal Hobart Hospital from 2008-2021. They were divided into pericardiotomy vs control group. Patient baseline demographics, intraoperative data, and post-operative outcomes were reviewed retrospectively. Total incidence of new POAF and cardiac tamponade was 26.1% and 0.75%, respectively. Primary outcome of both the incidence of POAF(22.9% vs27.8%OR 0.77 p<0.05) and Cardiac Tamponade (0% vs 1.1% OR 0.85 p<0.05) were less in the pericardiotomy group.Increasing age, BMI, poor left ventricular function (EF <30%), and return to theatre were independent predictors of developing POAF. There were similar rates of return to theatre for bleeding however, no cases of tamponade in the pericardiotomy group. There were no complications attributable to left posterior pericardiotomy and the time added to the duration of surgery was minimal. Left posterior pericardiotomy is associated with a significant reduction in the incidence of POAFand cardiac tamponade and issafe and efficient.

Keywords: cardiac surgery, pericardiotomy, post-operative atrial fibrillation, cardiac tamponade

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Authors: Rory Anthony Hutagalung, Leonardus Widjaja

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Microalgae Meyerella planktonica is a potential biofuel source because it can grow in bulk in either autotrophic or heterotrophic condition. However, the quantitative growth of this algal type is still low as it tends to precipitates on the bottom. Beside, the lipid concentration is still low when grown in autotrophic condition. In contrast, heterotrophic condition can enhance the lipid concentration. The combination of autotrophic condition and agitation treatment was conducted to increase the density of the culture. On the other hand, a heterotrophic condition was set up to raise the lipid production. A two-stage experiment was applied to increase the density at the first step and to increase the lipid concentration in the next step. The autotrophic condition resulted higher density but lower lipid concentration compared to heterotrophic one. The agitation treatment produced higher density in both autotrophic and heterotrophic conditions. The two-stage experiment managed to enhance the density during the autotrophic stage and the lipid concentration during the heterotrophic stage. The highest yield was performed by using 0.4% v/v glycerol as a carbon source (2.9±0.016 x 106 cells w/w) attained 7 days after the heterotrophic stage began. The lipid concentration was stable starting from day 7.

Keywords: agitation, glycerol, heterotrophic, lipid productivity, Meyerella planktonica

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Authors: Thiago Viana

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Eventually train accidents occur on railways and for some specific cases it is necessary to use a train rescue with a crane positioned under a platform wagon. These tumbled machines are collected and sent to the machine shop or scrap yard. In one of these cranes that were being used to rescue a wagon, occurred a fall of hoist due to fracture of two large pins. The two pins were collected and sent for failure analysis. This work investigates the main cause and the secondary causes for the initiation of the fatigue crack. All standard failure analysis procedures were applied, with careful evaluation of the characteristics of the material, fractured surfaces and, mainly, metallographic tests using an optical microscope to compare the geometry of the peaks and valleys of the thread of the pins and their respective seats. By metallographic analysis, it was concluded that the fatigue cracks were started from a notch (stress concentration) in the valley of the threads of the pin applied to the right side of the crane (pin 1). In this, it was verified that the peaks of the threads of the pin seat did not have proper geometry, with sharp edges being present that caused such notches. The visual analysis showed that fracture of the pin on the left side of the crane (pin 2) was brittle type, being a consequence of the fracture of the first one. Recommendations for this and other railway cranes have been made, such as nondestructive testing, stress calculation, design review, quality control and suitability of the mechanical forming process of the seat threads and pin threads.

Keywords: crane, fracture, pin, railway

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Authors: D. Kari Basavaraja, M. G. Skanda, C. Soumya, V. Ramesh

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This paper discusses the effects of sodium hypophosphite concentration, pH, and temperature on deposition rate. This paper also discusses the evaluation of coating strength, surface, and subsurface by varying the bath parameters, percentage of phosphate, plating temperature, and pH of the plating solution. Taguchi technique has been used for the analysis. In the experiment, nickel chloride which is a source of nickel when mixed with sodium hypophosphite has been used as the reducing agent and the source of phosphate and sodium hydroxide has been used to vary the pH of the coating bath. The coated samples are tested for impact energy by conducting impact test. Finally, the effects of coating bath parameters on the impact energy absorbed have been plotted, and analysis has been carried out. Further, percentage contribution of coating bath parameters using Design of Experiments approach (DOE) has been analysed. Finally, it can be concluded that the bath parameters of the Ni-P coating will certainly influence on the strength of the specimen.

Keywords: bath parameters, coatings, design of experiment, fracture toughness, impact strength

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Authors: D. S. Fardhyanti, A. Damayanti

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The utilization of biomass as a source of new and renewable energy is being carried out. One of the technologies to convert biomass as an energy source is pyrolysis which is converting biomass into more valuable products, such as bio-oil. Bio-oil is a liquid which is produced by steam condensation process from the pyrolysis of coconut shells. The composition of a coconut shell e.g. hemicellulose, cellulose and lignin will be oxidized to phenolic compounds as the main component of the bio-oil. The phenolic compounds in bio-oil are corrosive; they cause various difficulties in the combustion system because of a high viscosity, low calorific value, corrosiveness, and instability. Phenolic compounds are very valuable components which phenol has used as the main component for the manufacture of antiseptic, disinfectant (known as Lysol) and deodorizer. The experiments typically occurred at the atmospheric pressure in a pyrolysis reactor at temperatures ranging from 300 ^oC to 350 ^oC with a heating rate of 10 ^oC/min and a holding time of 1 hour at the pyrolysis temperature. The Gas Chromatography-Mass Spectroscopy (GC-MS) was used to analyze the bio-oil components. The obtained bio-oil has the viscosity of 1.46 cP, the density of 1.50 g/cm³, the calorific value of 16.9 MJ/kg, and the molecular weight of 1996.64. By GC-MS, the analysis of bio-oil showed that it contained phenol (40.01%), ethyl ester (37.60%), 2-methoxy-phenol (7.02%), furfural (5.45%), formic acid (4.02%), 1-hydroxy-2-butanone (3.89%), and 3-methyl-1,2-cyclopentanedione (2.01%).

Keywords: bio-oil, pyrolysis, coconut shell, phenol, gas chromatography-mass spectroscopy

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Authors: Mitsuhiro Okayasu

Abstract:

To better understand the lattice characteristics of lead zirconate titanate (PZT) ceramics, the lattice orientations and domain-switching characteristics have been directly examined during loading and unloading using various experimental techniques. Upon loading, the PZT ceramics are fractured linear and nonlinearly during the compressive loading process. The strain characteristics of the PZT ceramic were directly affected by both the lattice and domain switching strain. Due to the piezoelectric ceramic, electrical activity of lightning-like behavior occurs in the PZT ceramics, which attributed to the severe domain-switching leading to weak piezoelectric property. The characteristics of domain-switching and reverse switching are detected during the loading and unloading processes. The amount of domain-switching depends on the grain, due to different stress levels. In addition, two patterns of 90˚ domain-switching systems are characterized, namely (i) 90˚ turn about the tetragonal c-axis and (ii) 90˚ rotation of the tetragonal a-axis. In this case, PZT ceramic was loaded by the thermal stress at 80°C. Extent of domain switching is related to the direction of c-axis of the tetragonal structure, e.g., that axis, orientated close to the loading direction, makes severe domain switching. It is considered that there is 90˚ domain switching, but in actual, the angle of domain switching is less than 90˚, e.g., 85.4° ~ 90.0°. In situ TEM observation of the domain switching characteristics of PZT ceramic has been conducted with increasing the sample temperature from 25°C to 300°C, and the domain switching like behavior is directly observed from the lattice image, where the severe domain switching occurs less than 100°C.

Keywords: PZT, lead zirconate titanate, piezoelectric ceramic, domain switching, material property

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Authors: Mehdi Montakhabrazlighi, Ercan Balikci

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The neural network (NN) method is applied to alloy development of single crystal Ni-base Superalloys with low density and improved mechanical strength. A set of 1200 dataset which includes chemical composition of the alloys, applied stress and temperature as inputs and density and time to rupture as outputs is used for training and testing the network. Thermodynamic phase diagram modeling of the screened alloys is performed with Thermocalc software to model the equilibrium phases and also microsegregation in solidification processing. The model is first trained by 80% of the data and the 20% rest is used to test it. Comparing the predicted values and the experimental ones showed that a well-trained network is capable of accurately predicting the density and time to rupture strength of the Ni-base superalloys. Modeling results is used to determine the effect of alloying elements, stress, temperature and gamma-prime phase volume fraction on rupture strength of the Ni-base superalloys. This approach is in line with the materials genome initiative and integrated computed materials engineering approaches promoted recently with the aim of reducing the cost and time for development of new alloys for critical aerospace components. This work has been funded by TUBITAK under grant number 112M783.

Keywords: neural network, rupture strength, superalloy, thermocalc

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Authors: Vishakha Kaim, Mookan Natarajan, Sandeep Kaur-Ghumaan

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Hydrogen is one of the most abundant elements present on earth’s crust and considered to be the simplest element in existence. It is not found naturally as a gas on earth and thus has to be manufactured. Hydrogen can be produced from a variety of sources, i.e., water, fossil fuels, or biomass and it is a byproduct of many chemical processes. It is also considered as a secondary source of energy commonly referred to as an energy carrier. Though hydrogen is not widely used as a fuel, it still has the potential for greater use in the future as a clean and renewable source of energy. Electrocatalysis is one of the important source for the production of hydrogen which could contribute to this prominent challenge. Metals such as platinum and palladium are considered efficient for hydrogen production but with limited applications. As a result, a wide variety of metal complexes with earth abundant elements and varied ligand environments have been explored for the electrochemical production of hydrogen. In nature, [FeFe] hydrogenase enzyme present in DesulfoVibrio desulfuricans and Clostridium pasteurianum catalyses the reversible interconversion of protons and electrons into dihydrogen. Since the first structure for the enzyme was reported in 1990s, a range of iron complexes has been synthesized as structural and functional mimics of the enzyme active site. Mn is one of the most desirable element for sustainable catalytic transformations, immediately behind Fe and Ti. Only limited number manganese complexes have been reported in the last two decades as catalysts for proton reduction. Furthermore, redox reactions could be carried out in a facile manner, due to the capability of manganese complexes to be stable at different oxidation states. Herein are reported, four µ2-thiolate bridged manganese complexes [Mn₂(CO)₆(μ-S₂N₄C₁₄H₁₀)] 1, [Mn₂(CO)7(μ- S₂N₄C₁₄H₁₀)] 2, Mn₂(CO)₆(μ-S₄N₂C₁₄H₁₀)] 3 and [Mn₂(CO)(μ- S₄N₂C₁₄H₁₀)] 4 have been synthesized and characterized. The cyclic voltammograms of the complexes displayed irreversible reduction peaks in the range - 0.9 to -1.3 V (vs. Fc⁺/Fc in acetonitrile at 0.1 Vs⁻¹). The complexes were catalytically active towards proton reduction in the presence of trifluoroacetic acid as seen from electrochemical investigations.

Keywords: earth abundant, electrocatalytic, hydrogen, manganese

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Authors: F. Messaoudi, O. Haddad, R. Bouras, S. Kaci

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The development of self-compacting concrete (SCC) marks a huge step towards improved efficiency and working conditions on construction sites and in the precast industry. SCC flows easily into more complex shapes and through reinforcement bars, reduces the manpower required for the placement; no vibration is required to ensure correct compaction of concrete. This concrete contains a high volume of binder which is controlled by their rheological behavior. The paste consists of binders (Portland cement with or without supplementary cementitious materials), water, chemical admixtures and fillers. In this study, two series of tests were performed on self-compacting cement pastes made with marble waste additions as the mineral addition. The first series of this investigation was to determine the flow time of paste using Marsh cone, the second series was to determine the rheological parameters of the same paste namely yield stress and plastic viscosity using the rheometer Haake RheoStress 1. The results of this investigation allowed us to study the evolution of the yield stress, viscosity and the flow time Marsh cone paste as a function of the composition of the paste. A correlation between the results obtained on the flow test Marsh cone and those of the plastic viscosity on the mottled different cement pastes is proposed.

Keywords: adjuvant, rheological parameter, self-compacting cement pastes, waste marble

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Authors: Aleksandra Dudkowska, Gabriela Gic-Grusza

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Wind wave-induced sediment transport is an important multidimensional and multiscale dynamic process affecting coastal seabed changes and coastline evolution. The knowledge about sediment transport rate is important to solve many environmental and geotechnical issues. There are many types of sediment transport models but none of them is widely accepted. It is bacause the process is not fully defined. Another problem is a lack of sufficient measurment data to verify proposed hypothesis. There are different types of models for longshore sediment transport (LST, which is discussed in this work) and cross-shore transport which is related to different time and space scales of the processes. There are models describing bed-load transport (discussed in this work), suspended and total sediment transport. LST models use among the others the information about (i) the flow velocity near the bottom, which in case of wave-currents interaction in coastal zone is a separate problem (ii) critical bed shear stress that strongly depends on the type of sediment and complicates in the case of heterogeneous sediment. Moreover, LST rate is strongly dependant on the local environmental conditions. To organize existing knowledge a series of sediment transport models intercomparisons was carried out as a part of the project “Development of a predictive model of morphodynamic changes in the coastal zone”. Four classical one-grid-point models were studied and intercompared over wide range of bottom shear stress conditions, corresponding with wind-waves conditions appropriate for coastal zone in polish marine areas. The set of models comprises classical theories that assume simplified influence of turbulence on the sediment transport (Du Boys, Meyer-Peter & Muller, Ribberink, Engelund & Hansen). It turned out that the values of estimated longshore instantaneous mass sediment transport are in general in agreement with earlier studies and measurements conducted in the area of interest. However, none of the formulas really stands out from the rest as being particularly suitable for the test location over the whole analyzed flow velocity range. Therefore, based on the models discussed a new unified formula for longshore sediment transport rate estimation is introduced, which constitutes the main original result of this study. Sediment transport rate is calculated based on the bed shear stress and critical bed shear stress. The dependence of environmental conditions is expressed by one coefficient (in a form of constant or function) thus the model presented can be quite easily adjusted to the local conditions. The discussion of the importance of each model parameter for specific velocity ranges is carried out. Moreover, it is shown that the value of near-bottom flow velocity is the main determinant of longshore bed-load in storm conditions. Thus, the accuracy of the results depends less on the sediment transport model itself and more on the appropriate modeling of the near-bottom velocities.

Keywords: bedload transport, longshore sediment transport, sediment transport models, coastal zone

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Authors: Erfan Asghari Fesaghandis, Reza Ghaffari Adli, Abbas Kianvash, Hossein Aghajani, Homa Homaie

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NiTi alloys possess magnificent superelastic, shape memory, high strength and biocompatible properties. For improving mechanical properties, foremost, superelasticity behavior, heat treatment process is carried out. In this paper, two different heat treatment methods were undertaken: (1) solid solution, and (2) aging. The effect of each treatment in a constant time is investigated. Five samples were prepared to study the structure and optimize mechanical properties under different time and temperature. For measuring the upper plateau stress, lower plateau stress and residual strain, tensile test is carried out. The samples were aged at two different temperatures to see difference between aging temperatures. The sample aged at 500 °C has a bigger crystallite size and lower amount of Ni which causes the mentioned sample to possess poor pseudo elasticity behaviour than the other aged sample. The sample aged at 460 °C has shown remarkable superelastic properties. The mentioned sample’s higher plateau is 580 MPa with the lowest residual strain (0.17%) while other samples have possessed higher residual strains. X-ray diffraction was used to investigate the produced phases.

Keywords: heat treatment, phase transformation, superelasticity, NiTi alloy

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