Search results for: net handling stress

Authors: R. Sadeghzadegan, S. A. Naeini, A. Mirzaii

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In this article, the results of a series of carefully conducted laboratory test program were represented to determine the small strain shear modulus of sand mixed with a range of kaolinite including zero to 30%. This was experimentally achieved using a triaxial cell equipped with bender element. Results indicate that small shear modulus tends to increase, while clay content decreases and effective confining pressure increases. The exponent of stress in the power model regression analysis was not sensitive to the amount of clay content for all sand clay mixtures, while coefficient A was directly affected by change in clay content.

Keywords: small shear modulus, bender element test, plastic fines, sand

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Authors: Inkeri Jaaskelainen

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The aim of this study is to shed light on what is it like to study in apprenticeship training using intermediate (or even lower level) Finnish. The aim is to find out and describe these students' experiences and feelings while acquiring a profession in Finnish as it is important to understand how immigrant background adult learners learn and how their needs could be better taken into account. Many students choose apprenticeships and start vocational training while their language skills in Finnish are still very weak. At work, students should be able to simultaneously learn Finnish and do vocational studies in a noisy, demanding, and stressful environment. Learning and understanding new things is very challenging under these circumstances, and sometimes students get exhausted and experience a lot of stress - which makes learning even more difficult. Students are different from each other, and so are their ways to learn. Both duties at work and school assignments require reasonably good general language skills, and, especially at work, language skills are also a safety issue. The empirical target of this study is a group of students with an immigrant background who studied in various fields with intensive L2 support in 2016–2018 and who by now have completed a vocational upper secondary qualification. The interview material for this narrative study was collected from those who completed apprenticeship training in 2019–2020. The data collection methods used are a structured thematic interview, a questionnaire, and observational data. Interviewees with an immigrant background have an inconsistent cultural and educational background - some have completed an academic degree in their country of origin while others have learned to read and write only in Finland. The analysis of the material utilizes thematic analysis, which is used to examine learning and related experiences. Learning a language at work is very different from traditional classroom teaching. With evolving language skills, at an intermediate level at best, rushing and stressing makes it even more difficult to understand and increases the fear of failure. Constant noise, rapidly changing situations, and uncertainty undermine the learning and well-being of apprentices. According to preliminary results, apprenticeship training is well suited to the needs of an adult immigrant student. In apprenticeship training, students need a lot of support for learning and understanding a new communication and working culture. Stress can result in, e.g., fatigue, frustration, and difficulties in remembering and understanding. Apprenticeship training can be seen as a good path to working life. However, L2 support is a very important part of apprenticeship training, and it indeed helps students to believe that one day they will graduate and even get employed in their new country.

Keywords: apprenticeship training, vocational basic degree, Finnish learning, wee-being

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Authors: A. Elmikaty, Z. Thanawarothon, L. Mezeix

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This paper presents a finite element model to simulate the teeth failure of non-circular composite chainring. Model consists of the chainring and a part of the chain. To reduce the size of the model, only the first 11 rollers are simulated. In order to validate the model, it is firstly applied to a circular aluminum chainring and evolution of the stress in the teeth is compared with the literature. Then, effect of the non-circular shape is studied through three different loading positions. Strength of non-circular composite chainring and failure scenario is investigated. Moreover, two composite lay-ups are proposed to observe the influence of the stacking. Results show that composite material can be used but the lay-up has a large influence on the strength. Finally, loading position does not have influence on the first composite failure that always occurs in the first tooth.

Keywords: CFRP, composite failure, FEA, non-circular chainring

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Authors: Yolla Miranda, Marini Altyra, Karina Kalmapuspita Imas

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Oily sludge wastes always fill in upstream and downstream petroleum industry process. Sludge still contains oil that can use for energy storage. Recycling sludge is a method to handling it for reduce the toxicity and very probable to get the remaining oil around 20% from its volume. Froth flotation, a common method based on chemical unit for separate fine solid particles from an aqueous suspension. The basic composition of froth flotation is the capture of oil droplets or small solids by air bubbles in an aqueous slurry, followed by their levitation and collection in a froth layer. This method has been known as no intensive energy requirement and easy to apply. But the low efficiency and unable treat the high viscosity become the biggest problem in froth flotation unit. This study give the design to manage the high viscosity of sludge first and then entering the froth flotation including cavitation tube on it to change the bubbles into nano particles. The recovery in flotation starts with the collision and adhesion of hydrophobic particles to the air bubbles followed by transportation of the hydrophobic particle-bubble aggregate from the collection zone to the froth zone, drainage and enrichment of the froth, and finally by its overflow removal from the cell top. The effective particle separation by froth flotation relies on the efficient capture of hydrophobic particles by air bubbles in three steps. The important step is collision. Decreasing the bubble particles will increasing the collision effect. It cause the process more efficient. The pre-treatment, froth flotation, and cavitation tube integrated each other. The design shows the integrated unit and its process.

Keywords: sludge oil recovery, froth flotation, cavitation tube, nanobubbles, high viscosity

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Authors: Joanna Grzybowska, Magdalena Igras, Mariusz Ziółko

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Association rule learning is an approach for discovering interesting relationships in large databases. The analysis of relations, invisible at first glance, is a source of new knowledge which can be subsequently used for prediction. We used this data mining technique (which is an automatic and objective method) to learn about interesting affects associations in a corpus of emergency phone calls. We also made an attempt to match revealed rules with their possible situational context. The corpus was collected and subjectively annotated by two researchers. Each of 3306 recordings contains information on emotion: (1) type (sadness, weariness, anxiety, surprise, stress, anger, frustration, calm, relief, compassion, contentment, amusement, joy) (2) valence (negative, neutral, or positive) (3) intensity (low, typical, alternating, high). Also, additional information, that is a clue to speaker’s emotional state, was annotated: speech rate (slow, normal, fast), characteristic vocabulary (filled pauses, repeated words) and conversation style (normal, chaotic). Exponentially many rules can be extracted from a set of items (an item is a previously annotated single information). To generate the rules in the form of an implication X → Y (where X and Y are frequent k-itemsets) the Apriori algorithm was used - it avoids performing needless computations. Then, two basic measures (Support and Confidence) and several additional symmetric and asymmetric objective measures (e.g. Laplace, Conviction, Interest Factor, Cosine, correlation coefficient) were calculated for each rule. Each applied interestingness measure revealed different rules - we selected some top rules for each measure. Owing to the specificity of the corpus (emergency situations), most of the strong rules contain only negative emotions. There are though strong rules including neutral or even positive emotions. Three examples of the strongest rules are: {sadness} → {anxiety}; {sadness, weariness, stress, frustration} → {anger}; {compassion} → {sadness}. Association rule learning revealed the strongest configurations of affects (as well as configurations of affects with affect-related information) in our emergency phone calls corpus. The acquired knowledge can be used for prediction to fulfill the emotional profile of a new caller. Furthermore, a rule-related possible context analysis may be a clue to the situation a caller is in.

Keywords: data mining, emergency phone calls, emotional profiles, rules

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Authors: Olaniyi Awe, Adelana R. Adetunji, Abraham Adeleke

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Field observation revealed a lot of artisanal gold mining activities in Ilesa gold belt of southwestern Nigeria. The possibility of alluvial and lode gold deposits in commercial quantities around this location is very high, as there are many resident artisanal gold miners who have been mining and trading alluvial gold ore for decades and to date in the area. Their major process of solid gold recovery from its ore is by gravity concentration using the convectional panning method. This method is simple to learn and fast to recover gold from its alluvial ore, but its effectiveness is based on rules of thumb and the artisanal miners' experience in handling gold ore panning tool while processing the ore. Research samples from five alluvial gold ore tailings dumps were collected and studied. Samples were subjected to particle size analysis and mineralogical and elemental characterization using X-Ray Diffraction (XRD) and Particle-Induced X-ray Emission (PIXE) methods, respectively. The results showed that the tailings were of major quartz in association with albite, plagioclase, mica, gold, calcite and sulphide minerals. The elemental composition analysis revealed a 15ppm of gold concentration in particle size fraction of -90 microns in one of the tailings dumps investigated. These results are significant. It is recommended that heaps of panning tailings should be further reprocessed using other gold recovery methods such as shaking tables, flotation and controlled cyanidation that can efficiently recover fine gold particles that were previously lost into the gold panning tailings. The tailings site should also be well controlled and monitored so that these heavy minerals do not find their way into surrounding water streams and rivers, thereby causing health hazards.

Keywords: gold ore, panning, PIXE, tailings, XRD

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Authors: Wei Jun, Liao Hualin, Wang Huajian, Chen Jingkai, Liang Hongjun, Liu Chuanfu

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Kuqa Piedmont is rich in oil and gas resources and has great development potential in Tarim Basin, China. However, there is a huge thick gravel layer developed with high content, wide distribution and variation in size of gravel, leading to the condition of strong heterogeneity. So that, the drill string is in a state of severe vibration and the drill bit is worn seriously while drilling, which greatly reduces the rock-breaking efficiency, and there is a complex load state of impact and three-dimensional in-situ stress acting on the rock in the bottom hole. The dynamic mechanical properties and the influencing factors of conglomerate, the main component of gravel layer, are the basis of engineering design and efficient rock breaking method and theoretical research. Limited by the previously experimental technique, there are few works published yet about conglomerate, especially rare in dynamic load. Based on this, a kind of 3D SHPB system, three-dimensional prestress, can be applied to simulate the in-situ stress characteristics, is adopted for the dynamic test of the conglomerate. The results show that the dynamic strength is higher than its static strength obviously, and while the three-dimensional prestress is 0 and the loading strain rate is 81.25~228.42 s-1, the true triaxial equivalent strength is 167.17~199.87 MPa, and the strong growth factor of dynamic and static is 1.61~1.92. And the higher the impact velocity, the greater the loading strain rate, the higher the dynamic strength and the greater the failure strain, which all increase linearly. There is a critical prestress in the impact direction and its vertical direction. In the impact direction, while the prestress is less than the critical one, the dynamic strength and the loading strain rate increase linearly; otherwise, the strength decreases slightly and the strain rate decreases rapidly. In the vertical direction of impact load, the strength increases and the strain rate decreases linearly before the critical prestress, after that, oppositely. The dynamic strength of the conglomerate can be reduced properly by reducing the amplitude of impact load so that the service life of rock-breaking tools can be prolonged while drilling in the stratum rich in gravel. The research has important reference significance for the speed-increasing technology and theoretical research while drilling in gravel layer.

Keywords: huge thick gravel layer, conglomerate, 3D SHPB, dynamic strength, the deformation characteristics, prestress

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Authors: I Lamri, L Arabet, M. Hidjeb

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The direct shear test was used to determine the shear strength parameters C and Ø of a series of samples with different cement content. Samples stabilized with a certain percentage of cement showed a substantial gain in compressive strength and a significant increase in shear strength parameters. C and Ø. The laboratory equipment used in UCS tests consisted of a conventional 102mm diameter sample triaxial loading machine. Beyond 4% cement content a very important increase in shear strength was observed. It can be deduced from a comparative study of shear strength of soil samples with 4%, 7%, and 10% cement with sample containing 2 %, that the sample with a 4% cement content showed 90% increase in shear strength while those with 7% and 10% showed an increase of around 13 and 21 fold.

Keywords: cement, compression strength, shear stress, cohesion, angle of internal friction

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Authors: Anjali Uday, Yuting Wang, Andres Alfonso Pena Olare

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The Discrete Element Method is a promising approach to modeling microscopic behaviors of granular materials. The quality of the simulations however depends on the model parameters utilized. The present study focuses on calibration and validation of the discrete element parameters for Cuxhaven sand based on the experimental data from triaxial and oedometer tests. A sensitivity analysis was conducted during the sample preparation stage and the shear stage of the triaxial tests. The influence of parameters like rolling resistance, inter-particle friction coefficient, confining pressure and effective modulus were investigated on the void ratio of the sample generated. During the shear stage, the effect of parameters like inter-particle friction coefficient, effective modulus, rolling resistance friction coefficient and normal-to-shear stiffness ratio are examined. The calibration of the parameters is carried out such that the simulations reproduce the macro mechanical characteristics like dilation angle, peak stress, and stiffness. The above-mentioned calibrated parameters are then validated by simulating an oedometer test on the sand. The oedometer test results are in good agreement with experiments, which proves the suitability of the calibrated parameters. In the next step, the calibrated and validated model parameters are applied to forecast the micromechanical behavior including the evolution of contact force chains, buckling of columns of particles, observation of non-coaxiality, and sample inhomogeneity during a simple shear test. The evolution of contact force chains vividly shows the distribution, and alignment of strong contact forces. The changes in coordination number are in good agreement with the volumetric strain exhibited during the simple shear test. The vertical inhomogeneity of void ratios is documented throughout the shearing phase, which shows looser structures in the top and bottom layers. Buckling of columns is not observed due to the small rolling resistance coefficient adopted for simulations. The non-coaxiality of principal stress and strain rate is also well captured. Thus the micromechanical behaviors are well described using the calibrated and validated material parameters.

Keywords: discrete element model, parameter calibration, triaxial test, oedometer test, simple shear test

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Authors: N. Benkaci, E. Oubaiche, J.-L. Chatelain, R. Bensalem, K. Abbes

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The ambient vibration H/V technique is widely used nowadays in microzonation studies, because of its easy field handling and its low cost, compared to other geophysical methods. However, in presence of complex geology or lateral heterogeneity evidenced by more than one peak frequency in the H/V curve, it is difficult to interpret the results, especially when soil information is lacking. In this work, we focus on the construction site of the Baraki 40000=place stadium, located in the north-east side of the Mitidja basin (Algeria), to identify the seismic wave amplification zones. H/V curve analysis leads to the observation of spatial and time variability of the H/V frequency peaks. The spatial variability allows dividing the studied area into three main zones: (1) one with a predominant frequency around 1,5 Hz showing an important amplification level, (2) the second exhibits two peaks at 1,5 Hz and in the 4 Hz – 10 Hz range, and (3) the third zone is characterized by a plateau between 2 Hz and 3 Hz. These H/V curve categories reveal a consequent lateral heterogeneity dividing the stadium site roughly in the middle. Furthermore, a continuous ambient vibration recording during several weeks allows showing that the first peak at 1,5 Hz in the second zone, completely disappears between 2 am and 4 am, and reaching its maximum amplitude around 12 am. Consequently, the anthropogenic noise source generating these important variations could be the Algiers Rocade Sud highway, located in the maximum amplification azimuth direction of the H/V curves. This work points out that the H/V method is an important tool to perform nano-zonation studies prior to geotechnical and geophysical investigations, and that, in some cases, the H/V technique fails to reveal the resonance frequency in the absence of strong anthropogenic source.

Keywords: ambient vibrations, amplification, fundamental frequency, lateral heterogeneity, site effect

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Authors: Patel Himeshkumar Ashokbhai, Suchit Sharma, Arvind Kumar Garg

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The results obtained from settling test of coal fines are used as an important tool to select the dewatering equipment such as thickeners, centrifuges and filters. Coal being hydrophobic in nature does not easily settle when mixed with water. Coal slurry that takes longer time to release water is highly undesirable because it poses additional challenge during sedimentation, centrifuge and filtration. If filter cake has higher than permitted moisture content then it not only creates handling problems but inflated freight costs and reduction in input and productivity for coke oven charges. It is to be noted that coal fines drastically increase moisture percentage in filter cake hence are to be minimized. To increase settling rate of coal fines in slurry chemical substances called flocculants or coagulants are added that cause coal particles to flocculate or coalesce into larger particles. These larger particles settle at faster rate and have higher settling velocity. Other important factors affecting settling rate are flocculent dosage, slurry or pulp density and particle size. Hence in this paper we tried to study the settling characteristic of clean coal fines by varying one of the four factors namely 1. Flocculant Dosage (acryl-amide) 2. pH of the water 3. Bulk density 4. Particle size of clean coal fines in settling experiment and drew important conclusions. Result of this paper will be much useful not only for coal beneficiation plant design but also for cost reduction of coke production facilities.

Keywords: bulk density, coal fines, flocculants, flocculation, settling velocity, pH

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Authors: V. Kumar, K. Jha

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The present study is done to explore design modifications of the vortex finder, as it has a significant effect on the cyclone separator performance. It is evident that modifications of the vortex finder improve the performance of the cyclone separator significantly. The study conducted strives to improve the overall performance of cyclone separators by utilizing a converging-diverging (CD) vortex finder instead of the traditional uniform diameter vortex finders. The velocity and pressure fields inside a Stairmand cyclone separator with body diameter 0.29m and vortex finder diameter 0.1305m are calculated. The commercial software, Ansys Fluent v14.0 is used to simulate the flow field in a uniform diameter cyclone and six cyclones modified with CD vortex finders. Reynolds stress model is used to simulate the effects of turbulence on the fluid and particulate phases, discrete phase model is used to calculate the particle trajectories. The performance of the modified vortex finders is compared with the traditional vortex finder. The effects of the lengths of the converging and diverging sections, the throat diameter and the end diameters of the convergent divergent section are also studied to achieve enhanced performance. The pressure and velocity fields inside the vortex finder are presented by means of contour plots and velocity vectors and changes in the flow pattern due to variation of the geometrical variables are also analysed. Results indicate that a convergent-divergent vortex finder is capable of decreasing the pressure drop than that achieved through a uniform diameter vortex finder. It is also observed that the end diameters of the CD vortex finder, the throat diameter and the length of the diverging part of the vortex finder have a significant impact on the cyclone separator performance. Increase in the lower diameter of the vortex finder by 66% results in 11.5% decrease in the dimensionless pressure drop (Euler number) with 5.8% decrease in separation efficiency. Whereas 50% decrease in the throat diameter gives 5.9% increase in the Euler number with 10.2% increase in the separation efficiency and increasing the length of the diverging part gives 10.28% increase in the Euler number with 5.74% increase in the separation efficiency. Increasing the upper diameter of the CD vortex finder is seen to produce an adverse effect on the performance as it increases the pressure drop significantly and decreases the separation efficiency. Increase in length of the converging is not seen to affect the performance significantly. From the present study, it is concluded that convergent-divergent vortex finders can be used in place of uniform diameter vortex finders to achieve a better cyclone separator performance.

Keywords: convergent-divergent vortex finder, cyclone separator, discrete phase modeling, Reynolds stress model

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Authors: Jill Stephenson, Marie Vaganay, Robert Cameron, Caoimhe McGurk, Neil Hewitt

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Purpose: The key aim of the research was to identify the secondary stressors experienced by businesses affected by single or repeated flooding and to determine to what extent businesses were affected by these stressors, along with any resulting impact on health. Additionally, the research aimed to establish the likelihood of businesses being re-exposed to the secondary stressors through assessing awareness of flood risk, implementation of property protection measures and level of community resilience. Design/methodology/approach: The chosen research method involved the distribution of a questionnaire survey to businesses affected by either single or repeated flood events. The questionnaire included the Impact of Event Scale (a 15-item self-report measure which assesses subjective distress caused by traumatic events). Findings: 55 completed questionnaires were returned by flood impacted businesses. 89% of the businesses had sustained internal flooding while 11% had experienced external flooding. The results established that the key secondary stressors experienced by businesses, in order of priority, were: flood damage, fear of reoccurring flooding, prevention of access to the premise/closure, loss of income, repair works, length of closure and insurance issues. There was a lack of preparedness for potential future floods and consequent vulnerability to the emergence of secondary stressors among flood affected businesses, as flood resistance or flood resilience measures had only been implemented by 11% and 13% respectively. In relation to the psychological repercussions, the Impact of Event scores suggested that potential prevalence of post-traumatic stress disorder (PTSD) was noted among 8 out of 55 respondents (l5%). Originality/value: The results improve understanding of the enduring repercussions of flood events on businesses, indicating that not only residents may be susceptible to the detrimental health impacts of flood events and single flood events may be just as likely as reoccurring flooding to contribute to ongoing stress. Lack of financial resources is a possible explanation for the lack of implementation of property protection measures among businesses, despite 49% experiencing flooding on multiple occasions. Therefore it is recommended that policymakers should consider potential sources of financial support or grants towards flood defences for flood impacted businesses. Any form of assistance should be made available to businesses at the earliest opportunity as there was no significant association between the time of the last flood event and the likelihood of experiencing PTSD symptoms.

Keywords: flood event, flood resilience, flood resistance, PTSD, secondary stressors

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Authors: Najma Najam, Rukhsana Kausar, Rabia Hussain Kanwal, Saira Batool, Anum Javed

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In Pakistan, elderly population though increasing but it has been neglected by the researchers and policy makers which resulted in compromised quality of life of the ageing population. Two regions, Punjab and Gilgit-Baltistan (GB) were selected for comparison as Lahore and Multan (Punjab) are highly urbanized, large cities whereas Gilgit and Skardu are remote and mountain bounded valleys in GB. This study focuses on psychological and emotional functioning of elderly and a series of measures translated and adapted in Urdu language was used to assess quality of life, psychological and mental well-being, actual and perceived social support, attachment patterns, forgiveness, affects, geriatric depression, and emotional disturbance patterns (depression, anxiety, and stress) in elderly. A gender-equated sample of 201 elderly participants, 93 from GB (60 from Gilgit, 33 from Skardu) and 108 from Punjab (61 from Lahore, 47 from Multan) with over 60 years age was collected from the multiethnic community of Punjab and GB through purposive convenient sampling technique. Findings revealed that elderly from Multan have better psychological and emotional functioning, higher levels of social support, tendency to forgive, better mental wellbeing and quality of life and lower levels of stress, anxiety, depression, negative affect and attachment avoidance and anxiety related to partner as compared to the elderly from Lahore. Furthermore, both elderly male of Gilgit & Skardu have adequate mental well-being including subjective well-being and psychological functioning which showed positive aspects of mental health but elderly female are more attached to their home and neighbourhood which shows their social and environmental mastery. Gilgiti elderly male reported more degree of positive affect such as enthusiasm, active, alertness, excitement and strong whereas among elderly from Skardu shows more negative affect i.e. aversive mood states, irritability, hostility, and general distress. The need of psychosocial therapy and family counseling for the elderly in urban areas has been identified, which can facilitate in reducing or preventing the depressive and stressful tendencies. The findings are expected to have implications for improving quality of life of the elderly, designing interventions, support system and rehabilitation services to help them. However, findings may attract attention of policy makers and researchers as currently this is the most neglected population in Pakistan.

Keywords: psychological, emotional, aging, elderly, quality of life

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Authors: H. Mohammadi Majd, M. Jalali Azizpour, V. Tavaf, A. Jaderi

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In upsetting processes contact friction significantly influence metal flow, stress-strain state and process parameters. Furthermore, tribological conditions influence workpiece deformation and its dimensional precision. A viscoplastic constitutive law, the Anand model, was applied to represent the inelastic deformation behavior in upsetting process. This paper presents research results of the influence of contact friction coefficient on a workpiece deformation in upsetting process.finite element parameters. This technique was tested for three different specimens simulations of the upsetting and the corresponding material and can be successfully employed to predict the deformation of the upsetting process.

Keywords: friction, upsetting, barreling, Anand model

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Authors: Liliana Villavicencio, Yohn Garcia, Pallavi Singh, Luis Fernando Cruz, Wilfrido Moreno

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Psychophysiological adaptive automation is a concept that combines human physiological data and computer algorithms to create personalized interfaces and experiences for users. This approach aims to enhance human learning by adapting to individual needs and preferences and optimizing the interaction between humans and machines. According to neurosciences, the working memory demand during the student learning process is modified when the student is learning a new subject or topic, managing and/or fulfilling a specific task goal. A sudden increase in working memory demand modifies the level of students’ attention, engagement, and cognitive load. The proposed psychophysiological adaptive automation system will adapt the task requirements to optimize cognitive load, the process output variable, by monitoring the student's brain activity. Cognitive load changes according to the student’s previous knowledge, the type of task, the difficulty level of the task, and the overall psychophysiological state of the student. Scaling the measured cognitive load as low, medium, or high; the system will assign a task difficulty level to the next task according to the ratio between the previous-task difficulty level and student stress. For instance, if a student becomes stressed or overwhelmed during a particular task, the system detects this through signal measurements such as brain waves, heart rate variability, or any other psychophysiological variables analyzed to adjust the task difficulty level. The control of engagement and stress are considered internal variables for the hypermedia system which selects between three different types of instructional material. This work assesses the feasibility of a fuzzy controller to track a student's physiological responses and adjust the learning content and pace accordingly. Using an industrial automation approach, the proposed fuzzy logic controller is based on linguistic rules that complement the instrumentation of the system to monitor and control the delivery of instructional material to the students. From the test results, it can be proved that the implemented fuzzy controller can satisfactorily regulate the delivery of academic content based on the working memory demand without compromising students’ health. This work has a potential application in the instructional design of virtual reality environments for training and education.

Keywords: fuzzy logic controller, hypermedia control system, personalized education, psychophysiological adaptive automation

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Authors: Ali Azam Talukder, Jamsheda Ferdous Tuli, Tanzina Islam Reba, Shuvra Kanti Dey, Mamoru Yamada

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Recent global warming created by various pollutants prompted us to find new energy sources instead of fossil fuels. Fossil fuels are one of the key factors to emit various toxic gases in this planet. To solve this problem, along with the scarcity of the worldwide energy crisis, scientists are looking for various alternative options to mitigate the necessity of required future fuels. In this context, bioethanol can be one of the most suitable alternative energy sources. Bioethanol is a renewable, environment-friendly and carbon-neutral sustainable energy. In our previous study, we identified several bioethanol-producing microbes from the natural fermented sources of Bangladesh. Among them, the strain 4C encoded Saccharomyces cerevisiae produced maximum bioethanol when the fermentation temperature was 25˚C. In this study, we have established high-temperature simultaneous saccharification and fermentation process (HTSSF) by co-culturing of thermally adapted thermosensitive 4C as a fermenting agent and Bacillus amyloliquefaciens (C7), as a saccharifying agent under various physiological conditions or treatments. Conventional methods were applied for cell culture, media preparation and other experimental purposes. High-temperature adaptation of strain 4C was made from 30-42ᵒC, using either YPD or YPS media. In brief, for thermal adaptation, the temperature was periodically increased by 2ᵒC, 1ᵒC and 0.5ᵒC when medium growth temperatures were 30-36ᵒC, 36-40ᵒC, and 40-42ᵒC, respectively, where applicable. Amylase activity and bioethanol content were measured by DNS (3, 5-dinitrosalicylic acid) and solvent extraction and dichromate oxidation method, respectively. Among the various growth parameters like temperatures (30˚C, 37˚C and 42˚C), pHs (5.0, 6.0 and 7.0), carbon sources (5.0-10.0%) and ethanol stress tolerance (0.0-12.0%) etc. were tested, maximum Amylase activity (4.0 IU/ml/min) was recorded for Bacillus amyloliquefaciens (C7) at 42˚C, pH 6.0 and 10% starch. On the other hand, 4.10% bioethanol content was recorded when the thermally adapted strain 4C was co-cultured with C7 at 37ᵒC, pH 6.0 and 10.0% starch for 72 hours at HTSSF process. On the other hand, thermally non-adapted strains gave only 0.5-2.0% bioethanol content under the same physiological conditions. The thermally adapted strain 4C and strain C7, both can tolerate ethanol stress up to 12%. Altogether, a comparative study revealed that our established HTSSF process may be suitable for pilot scale and subsequently at industrial level bioethanol production.

Keywords: bioethanol, co-culture, fermentation, saccharification

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Authors: Meseret Gebeyehu Yehuala

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Women represent the majority of urban farmers engaged in vegetable and fruit production in Bahir Dar, Ethiopia. We examine urban agriculture in Bahir Dar city in the context of disruptions caused by the civil war and COVID-19. The Sustainable Livelihoods Framework serves as a conceptual frame to explore the vulnerability context, the structural and institutional challenges faced by women, and how this impacts their livelihoods. A total of 25 urban women farmers and 6 key informants were involved in the study through explorative and structured interviews conducted in 2021. Observations and informal conversations during repeated visits provided deeper insights. In addition, key informants employed in civil service institutions and experts were interviewed. Data were analysed by applying qualitative content analysis by using Atlas tia software. Women report that they experience a lack of access to land, insecurity of tenure, irregular technical support and input provision by agricultural extension services, and lack of access to credit and formal marketplaces. The COVID-19 pandemic restrictions aggravated this situation by delaying agricultural extension offices’ provision of necessary inputs and disrupting food handling and storage leading to the loss of perishable products. Bombing in relation to the civil war has destroyed harvests and left women in fear of returning to their fields. Women stated that vegetable and fruit production could contribute to their incomes, household food supplies, and more diversified diets. However, the city municipal office has, so far, not committed to supporting urban agriculture as a livelihood strategy.

Keywords: urban agriculture, institutional challenges, Bahir Dar, sustainable livelihood framework

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Authors: Hamdy M. Youssef, Mowffaq Oreijah, Hunaydi S. Alsharif

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In this paper, a three-dimensional model of the generalized thermoelasticity with one relaxation time and variable thermal conductivity has been constructed. The resulting non-dimensional governing equations together with the Laplace and double Fourier transforms techniques have been applied to a three-dimensional half-space subjected to thermal loading with rectangular pulse and traction free in the directions of the principle co-ordinates. The inverses of double Fourier transforms, and Laplace transforms have been obtained numerically. Numerical results for the temperature increment, the invariant stress, the invariant strain, and the displacement are represented graphically. The variability of the thermal conductivity has significant effects on the thermal and the mechanical waves.

Keywords: thermoelasticity, thermal conductivity, Laplace transforms, Fourier transforms

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Authors: Abdalrahman D. Alsulaili, Sheikha Y. Aljeraiwi, Athba N. Almanaie, Raghad Y. Alhajeri, Mariam Z. Almijren

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The water accompanying oil in the oil production process is increasing and due to its increasing rates a problem with handling it occurred. Current solutions like discharging into the environment, dumping water in evaporation pits, usage in the industry and reinjection in oil reservoirs to enhance oil production are used worldwide. The water injection method has been introduced to the oil industry with a process that either immediately injects water to the reservoir or goes to the filtration process before injection all depending on the porosity of the soil. Reinjection of unfiltered effluent water with high Total Suspended Solid (TSS) and Oil in Water (O/W) into soils with low porosity cause a blockage of pores, whereas soils with high porosity do not need high water quality. Our study mainly talks about the filtration and adsorption of the water using organic media as the adsorbent. An adsorbent is a substance that has the ability to physically hold another substance in its surface. Studies were done on nutshell and date pits with different surface areas and flow rates by using a 10inch filter connected with three tanks to perform as one system for the filtration process. Our approach in the filtration process using different types of medias went as follow: starting first with crushed nutshell, second with ground nutshell, and third using carbonized date pits with medium flow rate then high flow rate to compare different results. The result came out nearly as expected from our study where both O/W and TSS were reduced from our oily water sample by using this organic material. The effect of specific area was noticed when using nutshell as the filter media, where the crushed nutshell gave us better results than ground nutshell. The effect of flow rate was noticed when using carbonized date pits as the filter media whereas the treated water became more acceptable when the flow rate was on the medium level.

Keywords: date pits, nutshell, oil water, TSS

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Authors: M. Momoh, S. Abdullahi, A. U. Moreh

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Zinc oxide (ZnO) thin films were prepared on corning (7059) glass substrates at a thickness of 75.5 and 130.5 nm by RF sputtering technique. The deposition was carried out at room temperature after which the samples were annealed in open air at 150°C. The electrical and structural properties of these films were studied. The electrical properties of the films were monitored by four-point probe method while the structural properties were studied by X-ray diffraction (XRD). It was found that the electrical resistance of the films decreases with increase in the thickness of the films. The XRD analysis of the films showed that the films have a peak located at 34.31°-34.35° with hkl (002). Other parameters calculated include the stress (σ) and the grain size (D).

Keywords: electrical properties, film thickness, structural properties, zinc oxide

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Authors: Lucas Bublitz, Michael Herdrich

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By achieving the first commercialization approval in San Francisco the Autonomous Driving (AD) industry proves the technology maturity of the SAE L4 AD systems and the corresponding software and hardware stack. This milestone reflects the upcoming phase in the industry, where the focus is now about scaling and supervising larger autonomous vehicle (AV) fleets in different operation areas. This requires an operation framework, which organizes and assigns responsibilities to the relevant AV technology and operation stakeholders from the AV system provider, the Remote Intervention Operator, the MaaS provider and regulatory & approval authority. This holistic operation framework consists of technological, processual, and organizational activities to ensure safe operation for fully automated vehicles. Regarding the supervision of large autonomous vehicle fleets, a major focus is on the continuous field monitoring. The field monitoring approach must reflect the safety and security criticality of incidents in the field during driving operation. This includes an automatic containment approach, with the overall goal to avoid safety critical incidents and reduce downtime by a malfunction of the AD software stack. An End-to-end (E2E) field monitoring approach detects critical faults in the field, uses a knowledge-based approach for evaluating the safety criticality and supports the automatic containment of these E/E faults. Applying such an approach will ensure the scalability of AV fleets, which is determined by the handling of incidents in the field and the continuous regulatory compliance of the technology after enhancing the Operational Design Domain (ODD) or the function scope by Functions on Demand (FoD) over the entire digital product lifecycle.

Keywords: field monitoring, incident management, multicompliance management for AI in AD, root cause analysis, database approach

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Authors: Shao-Ying Wang, Shin-I Shih, Chi-Cheng Wu

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Background: By following to the maturity theory about age, the manifestation of depression in different age groups under occupational stressors still remains unclear. Therefore, the aim of this study was to examine the depression within four main symptoms clusters: cognition, affect, physical complaints and interpersonal difficulty among the different age groups. Additionally, this study also used the stress appraisal theory, through the examination of challenge and hindrance appraisals, the effects of cognitive factors were expected to give therapeutic indication for the future treatment of depression under abusive leadership. Methods (Participants and Procedure): The data were collected in two waves from employees of local companies in Taiwan. The participants (58 males and 167 females) were native Chinese speakers, ranging in age from 20 to 59 years (M= 36.51). Up to 80% educational level of participants were above senior high. The married population was approximately at 43%. Measures; 1. Abusive Leadership: To measure abusive leadership, we used 15-item scale of abusive supervision which anchored on a 7-point Likert-type scale. (α= .96) 2. Depression: We used Taiwanese Depression Scale to measure the 4 clusters (cognition, affect, physical complaints and interpersonal difficulty) of symptoms. Participants responded for depression anchored on a 7-point Likert-type scale (α= .96). 3. Stress Appraisal Scale: To measure challenge and hindrance types of appraisal, participants responded to 33-item measure anchored on a 7-point Likert-type scale. (Challenge appraisal; α= .90; hindrance appraisal α= .87). Results: The results of correlation showed that there was a significant and negative correlation between abusive leadership and age (r = - .21, p < .01). Abusive leadership was positive correlated significantly with hindrance appraisal (r = .52, p < .01) and depression (r = .20, p < .01). The results also showed that hindrance appraisal was correlated to depression positively (r = .36, p < .01). A one-way ANOVA was conducted to compare the effect of lower/middle/order age groups on each cluster of depressive symptoms. The results showed that the effect of age groups on cognition was significant F (2, 157) =3.66, P < .05. Older age group (M=13.43 SD=6.84) reported less cognitive symptoms of depression than the middle (M=16.77 SD=7.49) and lower age (M=16.91 SD=6.97) groups. Besides, the effect of age groups on affect was also significant F (2,157)= 4.09 P < .05. Older age group (M=18.68 SD=8.98) reported less affective symptoms of depression than the middle (M=22.01 SD=7.96) and lower age (M=23.56 SD=7.67) groups. Moreover, the main effect of hindrance appraisal was found F (2, 157) =3.81, P < .05. Older age group (M=9.44 SD=2.89) reported fewer score on hindrance appraisals than the middle (M=11.06 SD=4.02) and lower age (M=9.62 SD=3.17) groups. To conclude, the severity of depression symptoms varies across different age groups. Maturity seems to be the protective factor to depression, accompanying with lower hindrance appraisals.

Keywords: abusive leadership, affective commitment, depression symptoms, psychological well-being

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Authors: Yogita Weikey, Shobha Lata Sinha, Satish Kumar Dewangan

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In the present investigation, rheology of the three different natural gums has been evaluated experimentally using MCR 102 rheometer. Various samples based on the variation of the concentration of the solid gum powder have been prepared. Their non-Newtonian behavior has been observed by the consistency plots and viscosity variation plots with respect to different solid concentration. The viscosity-shear rate curves of gums are similar and the behavior is shear thinning. Gums are showing pseudoplastic behavior. The value of k and n are calculated by using various models. Results show that the Herschel–Bulkley rheological model is reliable to describe the relationship of shear stress as a function of shear rate. R² values are also calculated to support the choice of gum selection.

Keywords: bentonite, Indian gum, non-Newtonian model, rheology

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Authors: Shahram Naghizadeh Raeisi, Ali Alghooneh

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The loss of curd cohesiveness and syneresis are two common problems in the ultrafiltered cheese industry. In this study, by using membrane technology and protein modification, a modified cheese was developed and its properties were compared with a control sample. In order to decrease the lactose content and adjust the protein, acidity, dry matter and milk minerals, a combination of ultrafiltration, nanofiltration and reverse osmosis technologies was employed. For protein modification, a two-stage chemical and enzymatic reaction was employed before and after ultrafiltration. The physicochemical and microstructural properties of the modified ultrafiltered cheese were compared with the control one. Results showed that the modified protein enhanced the functional properties of the final cheese significantly (pvalue< 0.05), even if the protein content was 50% lower than the control one. The modified cheese showed 21 ± 0.70, 18 ± 1.10 & 25±1.65% higher hardness, cohesiveness and water-holding capacity values, respectively, than the control sample. This behavior could be explained by the developed microstructure of the gel network. Furthermore, chemical-enzymatic modification of milk protein induced a significant change in the network parameter of the final cheese. In this way, the indices of network linkage strength, network linkage density, and time scale of junctions were 10.34 ± 0.52, 68.50 ± 2.10 & 82.21 ± 3.85% higher than the control sample, whereas the distance between adjacent linkages was 16.77 ± 1.10% lower than the control sample. These results were supported by the results of the textural analysis. A non-linear viscoelastic study showed a triangle waveform stress of the modified protein contained cheese, while the control sample showed rectangular waveform stress, which suggested a better sliceability of the modified cheese. Moreover, to study the shelf life of the products, the acidity, as well as molds and yeast population, were determined in 120 days. It’s worth mentioning that the lactose content of modified cheese was adjusted at 2.5% before fermentation, while the lactose of the control one was at 4.5%. The control sample showed 8 weeks shelf life, while the shelf life of the modified cheese was 18 weeks in the refrigerator. During 18 weeks, the acidity of modified and control samples increased from 82 ± 1.50 to 94 ± 2.20 °D and 88 ± 1.64 to 194 ± 5.10 °D, respectively. The mold and yeast populations, with time, followed the semicircular shape model (R2 = 0.92, R2adj = 0.89, RMSE = 1.25). Furthermore, the mold and yeast counts and their growth rate in the modified cheese were lower than those for control one; Aforementioned result could be explained by the shortage of the source of energy for the microorganism in the modified cheese. The lactose content of the modified sample was less than 0.2 ± 0.05% at the end of fermentation, while this was 3.7 ± 0.68% in the control sample.

Keywords: non-linear viscoelastic, protein modification, semicircular shape model, ultrafiltered cheese

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Authors: Zelikha Labbani

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The in vitro isolated microspore culture is the most powerful androgenic pathway to produce doubled haploid plants in the short time. To deviate a microspore toward embryogenesis, a number of factors, different for each species, must concur at the same time and place. Once induced, the microspore undergoes numerous changes at different levels, from overall morphology to gene expression. Induction of microspore embryogenesis not only implies the expression of an embryogenic program, but also a stress-related cellular response and a repression of the gametophytic program to revert the microspore to a totipotent status. As haploid single cells, microspore became a strategy to achieve various objectives particularly in genetic engineering. In this communication we would show the most recent advances in the producing haploid embryos via in vitro isolated microspore culture.

Keywords: in vitro isolated microspore culture, success, haploid cells, bioinformatics, biomedicine

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Authors: May George

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Inference plays an important role in the learning process and it can lead to a rapid acquisition of a second language. When learning a non-native language, i.e., a critical language like Arabic, the students depend on the teacher’s support most of the time to learn new concepts. The students focus on memorizing the new vocabulary and stress on learning all the grammatical rules. Hence, the students became mechanical and cannot produce the language easily. As a result, they are unable to predict the meaning of words in the context by relying heavily on the teacher, in that they cannot link their prior knowledge or even identify the meaning of the words without the support of the teacher. This study explores how the teacher guides students learning during the inference process and what are the processes of learning that can direct student’s inference.

Keywords: inference, reading, Arabic, language acquisition

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Authors: Jignasha Derasari, Patel Krishna M, Modi Jignasa G.

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Chemical stability of pharmaceutical molecules is a matter of great concern as it affects the safety and efficacy of the drug product.Stability testing data provides the basis to understand how the quality of a drug substance and drug product changes with time under the influence of various environmental factors. Besides this, it also helps in selecting proper formulation and package as well as providing proper storage conditions and shelf life, which is essential for regulatory documentation. The ICH guideline states that stress testing is intended to identify the likely degradation products which further help in determination of the intrinsic stability of the molecule and establishing degradation pathways, and to validate the stability indicating procedures. A simple, accurate and precise stability indicating RP- HPLC method was developed and validated for simultaneous estimation of Amiloride Hydrochloride and Furosemide in tablet dosage form. Separation was achieved on an Phenomenexluna ODS C18 (250 mm × 4.6 mm i.d., 5 µm particle size) by using a mobile phase consisting of Ortho phosphoric acid: Acetonitrile (50:50 %v/v) at a flow rate of 1.0 ml/min (pH 3.5 adjusted with 0.1 % TEA in Water) isocratic pump mode, Injection volume 20 µl and wavelength of detection was kept at 283 nm. Retention time for Amiloride Hydrochloride and Furosemide was 1.810 min and 4.269 min respectively. Linearity of the proposed method was obtained in the range of 40-60 µg/ml and 320-480 µg/ml and Correlation coefficient was 0.999 and 0.998 for Amiloride hydrochloride and Furosemide, respectively. Forced degradation study was carried out on combined dosage form with various stress conditions like hydrolysis (acid and base hydrolysis), oxidative and thermal conditions as per ICH guideline Q2 (R1). The RP- HPLC method has shown an adequate separation for Amiloride hydrochloride and Furosemide from its degradation products. Proposed method was validated as per ICH guidelines for specificity, linearity, accuracy; precision and robustness for estimation of Amiloride hydrochloride and Furosemide in commercially available tablet dosage form and results were found to be satisfactory and significant. The developed and validated stability indicating RP-HPLC method can be used successfully for marketed formulations. Forced degradation studies help in generating degradants in much shorter span of time, mostly a few weeks can be used to develop the stability indicating method which can be applied later for the analysis of samples generated from accelerated and long term stability studies. Further, kinetic study was also performed for different forced degradation parameters of the same combination, which help in determining order of reaction.

Keywords: amiloride hydrochloride, furosemide, kinetic study, stability indicating RP-HPLC method validation

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Authors: Mariateresa Torchia, Helene Cristini, Hannele Kauppinen

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Leadership plays a vital role in organizations. Leaders provide directions and facilitate the processes that enable organizations to achieve their goals and objectives. However, while productivity and financial objectives are often given the greatest emphasis, leaders also have the responsibility for instituting standards of ethical conduct and moral values that guide the behavior of employees. Leaders’ behaviors such as support, empowerment and a high-quality relationship with their employees might not only prevent stress, but also improve employees’ stress coping meanwhile contributing to their affective well-being. Stemming from Girard’s Mimetic Theory, this study aims at understanding how leaders can foster well-being in organizations. To do so, we explore which is the role leaders play in conflict management, resentment management and negative emotions dissipation. Furthermore, we examine whether and to what extent religiosity impacts the way in which leaders operate in relation to employees’ well-being. Indeed, given that organizational values are crucial to ethical behavior and firms’ values may be steeled by a deep sense of spirituality and religious identification, there is a need to take a closer look at the role religion and spirituality play in influencing the way leaders impact employees’ well-being. Thus, religion might work as an overarching logic that provides a set of principles guiding leaders’ everyday practices and relations with employees. We answer our research questions using a qualitative approach. We interviewed 27 Christian leaders (members of the Christian Entrepreneurs and Leaders Association – EDC, a non-profit organization created in 1926 including 3,000 French Christian Leaders & Entrepreneurs). Our results show that well-being can have a different meaning in relation to the type of companies, size, culture, country of analysis. Moreover the values and believes of leaders influence the way they see and foster well-being among employees. Furthermore, leaders can have both a positive or negative impact on well-being. Indeed on the one side, they could increase well-being in the company while on the other hand, they could be the source of resentment and conflicts among employees. Finally, we observed that Christian leaders possess characteristics that are sometimes missing in leaders (humility, inability to compare with others, attempt to be coherent with their values and beliefs, interest in the common good instead of the personal interest, having tougher dilemmas, collectively undertaking the firm). Moreover the Christian leader believes that the common good should come before personal interest. In other words, to them, not only short –termed profit shouldn’t guide strategical decisions but also leaders should feel responsible for their employees’ well-being. Last but not least, the study is not an apologia of Christian, yet it discusses the implications of these values through the light of Girard’s mimetic theory for both theory and practice.

Keywords: Christian leaders, employees well-being, leadership, mimetic theory

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Authors: Cledinaldo A. Dias, Isabela C. Santos, Marcus V. S. Siqueira

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In the contemporary globalization, the competitiveness generated in the search of new markets aiming at the growth of productivity and, consequently, of profits, implies the redefinition of productive processes and new forms of work organization. As a result of this structuring, unemployment, labor force turnover and the increase in outsourcing and informal work occur. Considering the different relationships and working conditions of outsourced employees, this study aims to identify the most present stressors among outsourced service providers from a Federal Institution of Higher Education in Brazil. To reach this objective, a descriptive exploratory study with a quantitative approach was carried out. The qualitative approach was chosen to provide an in-depth analysis of the occupational conditions of outsourced workers since this method seeks to focus on the social as a world of investigated meanings and the language or speech of each subject as the object of this approach. The survey was conducted in the city of Montes Claros - Minas Gerais (Brazil) and involved eighty workers from companies hired by the institution, including armed security guards, porters, cleaners, drivers, gardeners, and administrative assistants. The choice of professionals obeyed non-probabilistic criteria for convenience or accessibility. Data collection was performed by means of a structured questionnaire composed of sixty questions, in a Likert-type frequency interval scale format, in order to identify potential organizational stressors. The results obtained evidence that the stress factors pointed out by the workers are, in most cases, a determining factor due to the low productive performance at work. Amongst the factors associated with stress, the ones that stood out most were those related to organizational communication failures, the incentive to competition, lack of expectations of professional growth, insecurity and job instability. Based on the results, the need for greater concern and organizational responsibility with the well-being and mental health of the outsourced worker and the recognition of their physical and psychological limitations, and care that goes beyond the functional capacity for the work. Specifically for the preservation of mental health, physical and quality of life, it is concluded that it is necessary for the professional to be inserted in the external world that favors it internally since this set is complemented so that the individual remains in balance and obtain satisfaction in your work.

Keywords: occupational health, outsourced, organizational studies, stressors

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