Search results for: complex correlation measure

Authors: Jane E. A. Lewis, Paul Williams, Jane H. Davies

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Introduction: There is, at present, a clear and recognized need to optimize the diagnosis of peripheral arterial disease (PAD), particularly in non-specialist settings such as primary care, and this arises from several key facts. Firstly, PAD is a highly prevalent condition. In 2010, it was estimated that globally, PAD affected more than 202 million people and furthermore, this prevalence is predicted to further escalate. The disease itself, although frequently asymptomatic, can cause considerable patient suffering with symptoms such as lower limb pain, ulceration, and gangrene which, in worse case scenarios, can necessitate limb amputation. A further and perhaps the most eminent consequence of PAD arises from the fact that it is a manifestation of systemic atherosclerosis and therefore is a powerful predictor of coronary heart disease and cerebrovascular disease. Objective: This cross sectional study aimed to individually and cumulatively compare sensitivity and specificity of the (i) ankle brachial index (ABI) and (ii) pulse volume waveform (PVW) recorded by the same automated device, with the presence or absence of peripheral arterial disease (PAD) being verified by an Ultrasound Duplex Scan (UDS). Methods: Patients (n = 205) referred for lower limb arterial assessment underwent an ABI and PVW measurement using volume plethysmography followed by a UDS. Presence of PAD was recorded for ABI if < 0.9 (noted if > 1.30) if PVW was graded as 2, 3 or 4 or a hemodynamically significant stenosis > 50% with UDS. Outcome measure was agreement between measured ABI and interpretation of the PVW for PAD diagnosis, using UDS as the reference standard. Results: Sensitivity of ABI was 80%, specificity 91%, and overall accuracy 88%. Cohen’s kappa revealed good agreement between ABI and UDS (k = 0.7, p < .001). PVW sensitivity 97%, specificity 81%, overall accuracy 84%, with a good level of agreement between PVW and UDS (k = 0.67, p < .001). The combined sensitivity of ABI and PVW was 100%, specificity 76%, and overall accuracy 85% (k = 0.67, p < .001). Conclusions: Combing these two diagnostic modalities within one device provided a highly accurate method of ruling out PAD. Such a device could be utilized within the primary care environment to reduce the number of unnecessary referrals to secondary care with concomitant cost savings, reduced patient inconvenience, and prioritization of urgent PAD cases.

Keywords: ankle brachial index, peripheral arterial disease, pulse volume waveform, ultrasound duplex scan

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Authors: Stela Doncheva

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Postpartum distress, encompassing depressive symptoms, obsessions, and anxiety, remains a subject of significant scientific interest due to its prevalence among individuals giving birth. This critical and transformative period presents a multitude of factors that impact women's health. On the one hand, variables such as social support, satisfaction in romantic relationships, shared newborn care, and birth satisfaction directly affect the mental well-being of new mothers. On the other hand, the interplay of hormonal changes, personality characteristics, emotional difficulties, and the profound life adjustments experienced by mothers can profoundly influence their self-esteem and overall physical and emotional well-being. This paper extensively explores the factors of alexithymia, social support, partners' support, and birth satisfaction to gain deeper insights into their impact on postpartum distress. Utilizing a qualitative survey consisting of six self-reflective questionnaires, this study collects valuable data regarding the individual postpartum experiences of Bulgarian mothers. The primary objective is to enrich our understanding of the complex factors involved in the development of postpartum distress during this crucial period. The results shed light on the intricate nature of the problem and highlight the significant influence of bio-psycho-social elements. By contributing to the existing knowledge in the field, this research provides valuable implications for the development of interventions and support systems tailored to the unique needs of mothers in the postpartum period. Ultimately, this study aims to improve the overall well-being of new mothers and promote optimal maternal health during the postpartum journey.

Keywords: maternal mental health, postpartum distress, postpartum depression, postnatal mothers

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Authors: Dalila Lino

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Practicum is a central dimension of teacher education programs. Learning how to teach is, in effect, a complex process that integrates periods of observation, experimentation, reflection, planning, and evaluation in a real context of practices, providing opportunities for prospective teachers to understand the various dimensions of education and to implement the knowledge built over the theoretical courses they have taken. At the pre-service training of early childhood teachers, specialized guidance and in particular pedagogical supervision assumes a key role in the professional development of students in training. The main goal of this study is to describe and analyze the supervision process that occurs during the practicum of preschool education master programs in Portugal. The objectives of the study are: (i) to describe the cooperative process of professional development experienced by student teachers during the practicum; (ii) to identify the strengths and weaknesses of supervision process; (iii) to identify the supervision styles used by university supervisors and cooperating teachers. The methodology used is the mix-method research and data was collected through semi-structured interviews and online questionnaires. The participants are newly graduated Portuguese early childhood teachers, university supervisors and cooperating teachers. The results reveal gaps in the specialized training of cooperating teachers and university supervisors, a large number of trainees per supervisor, which makes it difficult to support students, and those interpersonal relationships between university supervisors and students and/or cooperating teachers and students interfere in the development of the supervisory processes. The study highlights the need to invest in the specialized training of university supervisors and cooperating teachers to create better opportunities to support the professional development of prospective teachers.

Keywords: mentoring, pedagogical supervision, practicum, preschool teacher education

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Authors: Faizah Asiri, Mohammed Fathy, Saeed Alghamdi, Nahlah Ayoub, Faisal Asiri

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Background: - The strategies for this study were based on the toxic effect of long-term inhalation of Benzene on hormones and liver enzymes and various parameters related to it. The following databases were searched: benzene, hepatotoxic, benzene metabolism, hormones, testosterone, hemotoxic, and prolonged exposure. A systematic strategy is designed to search the literature that links benzene with the multiplicity and different types of intoxication or the medical abbreviations of diseases relevant to benzene exposure. Evidence suggests that getting rid of inhaled gasoline is by exhalation. Absorbed benzene is metabolized by giving phenolic acid as well as meconic acid, followed by urinary excretion of conjugate sulfates and glucuronides. Materials and Methods :- This work was conducted in the Al-Khadra laboratory in Taif 2020/2021 and aimed to measure some of the possible endocrinal and liver toxicities associated with benzene's long-term exposure in Saudi Arabia at the station workers who are considered the most exposed category to gasoline. One hundred ten station workers were included in this study. They were divided into four patient groups according to the chronic exposure rate to benzene, one control group, and three other groups of exposures. As follows: patient Group 1 (controlled group), patient Group 2 (exposed less than 1y), patient Group 3 (exposed 1-5 y), patient Group 4 (more than 5). Each group is compared with blood sample parameters (ALT, FSH and Testosterone, TSH). Blood samples were drawn from the participants, and statistical tests were performed. Significant change (p≤0.05) was examined compared to the control group. Workers' exposure to benzene led to a significant change in hematological, hormonal, and hepatic factors compared to the control group. Results:- The results obtained a relationship between long-term exposure to benzene and a decrease in the level of testosterone and FSH hormones, including that it poses a toxic risk in the long term (p≤0.05) when compared to the control. We obtained results confirming that there is no significant coloration between years of exposure and TSH level (p≤0.05) when compared to the control. Conclusion:- We conclude that some hormones and liver enzymes are affected by chronic doses of benzene through inhalation after our study was on the group most exposed to benzene, which is gas station workers.

Keywords: toxicities, benzene, hormones, station workers

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Authors: Ejaz Ali M. Phil

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Enterprise Resource Planning (ERP) systems are playing a vital role in effective management of business functions in large and complex organizations. Human Resource Information System (HRIS) is a core module of ERP, providing concrete solutions to implement Human Resource Management (HRM) Practices in an innovative and efficient manner. Over the last decade, there has been considerable increase in the studies on HRIS. Nevertheless, previous studies relatively lacked to examine the moderating role of HRIS in performing HRM practices that may affect the firms’ performance. The current study was carried out to examine the impact of HRM practices (training, performance appraisal) on perceived organizational performance, with moderating role of HRIS, where the system is in place. The study based on Resource Based View (RBV) and Ability Motivation Opportunity (AMO) Theories, advocating that strengthening of human capital enables an organization to achieve and sustain competitive advantage which leads to improved organizational performance. Data were collected through structured questionnaire based upon adopted instruments after establishing reliability and validity. The structural equation modeling (SEM) were used to assess the model fitness, hypotheses testing and to establish validity of the instruments through Confirmatory Factor Analysis (CFA). A total 220 employees of 25 firms in corporate sector were sampled through non-probability sampling technique. Path analysis revealing that HRM practices and HRIS have significant positive impact on organizational performance. The results further showed that the HRIS moderated the relationships between training, performance appraisal and organizational performance. The interpretation of the findings and limitations, theoretical and managerial implications are discussed.

Keywords: enterprise resource planning, human resource, information system, human capital

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Authors: Deborah Idowu

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This research delves into the effectiveness of explicitly teaching productive non-cognate French suffixes to English beginner learners of the French language. It is widely accepted that cognates, especially orthographic ones, can be inferred by learners from their first language (in this case, English). The same is the case for derived French words with cognate suffixes, provided the learner is familiar with the lemma, which can either be cognate or non-cognate. However, the same cannot be said for derived French words with non-cognate suffixes. These suffixes often pose challenges to learners, even when the base word is familiar to them. The primary goal of this research is to enhance the vocabulary comprehension and expansion of English-speaking beginners in French by focusing on the recognition of derived French words that may not align with their L1 knowledge. The methodology employed in this study of derivational morphology involves an experimental group receiving explicit instruction on productive non-cognate suffixes, while a control group does not. By utilizing confidence ratings and other analytical tools, the analysis aims to measure the impact of this targeted instruction on the learners' ability to understand and incorporate non-cognate suffixes into their French vocabulary. Through this experimental approach, the research seeks to provide valuable insights into how explicit instruction on non-cognate suffixes can benefit beginner French learners, ultimately aiding them in navigating the intricacies of French derivational morphology. The objectives of this research are as follows: i. to investigate the impact of explicitly teaching productive non-cognate suffixes on the vocabulary comprehension and expansion of beginner learners of the French language; ii. to assess the effectiveness of targeted instruction on non-cognate suffixes in aiding English-speaking learners in recognizing and understanding derived French words that may not align with their native language knowledge, iii. to compare the vocabulary acquisition and retention of beginner French learners who receive explicit instruction on non-cognate suffixes with those who do not to determine the effectiveness of this instructional approach, iv. to analyze the confidence ratings and other analytical methods to gauge the learners' ability to integrate non-cognate suffixes into their French vocabulary and comprehend the meaning of derived words more effectively, v. to contribute insights into how explicit instruction on non-cognate suffixes can enhance the overall language learning experience for beginner learners of French, particularly in the area of French derivational morphology.

Keywords: suffixes, derivational morphology, non-cognates, vocabulary acquisition, French language learners

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Authors: Arkadiusz Gut, Joanna Afek

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The first issue that we discuss in this paper is a battery of research demonstrating that culture influences children’s performance in tasks testing their theory of mind, also known as mindreading. We devote special attention to research done within Chinese culture; namely, studies with children speaking Cantonese and Mandarin natively and growing up in an environment dominated by the Chinese model of informal home education. Our attention focuses on the differences in development and functioning of social abilities and competences between children from China and the West. Another matter we turn to is the description of the nature of Chinese early childhood education. We suggest that the differences between the Chinese model and that of the West reveal a set of modifiers responsible for the variation observed in empirical research on children’s theory of mind (mindreading). The modifiers we identify are the following: (1) early socialization – that is, the transformation of the child into a member of the family and society that set special value by the social and physical environment; (2) the Confucian model of education – that is, the Chinese alphabet and tradition that determine a certain way of education in China; (3) the authoritarian style of upbringing – that is, reinforcing conformism, discouraging voicing of private opinions, and respect for elders; (4) the modesty of children and protectiveness of parents – that is, obedience as a desired characteristic in the child, overprotectiveness of parents, especially mothers; and (5) gender differences – that is, different educational styles for girls and boys. In our study, we conduct a thorough meta-analysis of empirical data on the development of mindreading and ToM (children’s theory of mind), as well as a cultural analysis of early childhood education in China. We support our analyses with questionnaire and narrative studies conducted in China that use the ‘Children’s Social Understanding Scale’ questionnaire, conversations based on the so-called ‘Scenarios Presented to Parents’, and questions designed to measure the ‘my child and I’ relation. With our research we aim to identify the factors in early childhood education that serve as moderators explaining the nature of the development and functioning of social cognition based on mind reading in China. Additionally, our study provides a valuable insight for comparative research of social cognition between China and the West.

Keywords: early childhood education, China, mindreading, parenting

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Authors: Sadaf Ambreen, Ayesha Bibi, Sara Rafiq

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Hypertension is a medical condition in which blood pressure in the arteries is elevated than the normal, having systolic blood pressure more than 120mmHg and diastolic blood pressure more than 80 mmHg. It leads to health complications and increase the risk of diseases such as stroke, heart failure, heart attack, and even death. The aim of the current study was to evaluate nutritional status and activity level among hypertensive early adults in District Mardan Data was collected from the subjects of Public Hospital, Mardan Medical Complex, through questionnaire. A complete information about individual sociodemographic, anthropometry and health status were collected, and physical activity was assessed by using IPAQ questionnaire. A total of 150 individuals were included in the study, in which 90% were females, and 10% were males. Data was analyzed through SPSS Version 22. Majority of the study subjects, 88%, were married, 70% having nuclear living system, 43% were having elementary education, and 43% were working as laborer. Body mass index and waist circumference in female counterpart were found to be positively associated with hypertension and was found statistically significant P=<0.01. Results showed that majority of females were fall in hypertension crisis category with mild activity, and males were having hypertension stage 1 with moderate activity. Our study concluded that non-optimal nutritional status and physical inactivity resulted in elevated blood pressure in females, therefore, lifestyle change such as optimal nutritional status and physical activity may play key role in reducing risk of hypertension.

Keywords: obesity/overwight, body mass index, waist circumference, early adulthood

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Authors: Kyoko Tominaga

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Non-Government Organizations (NGOs), Non-Profit Organizations (NPOs), Social Enterprises and other actors play an important role in political decisions in governments at the international levels. Especially, such organizations’ and activists’ network in civil society is quite important to effect to the global politics. To solve the complex social problems in global era, diverse actors should corporate each other. Moreover, network of protesters is also contributes to diffuse tactics, information and other resources of social movements. Based on the findings from the study of International Trade Fairs (ITFs), the author analyzes the network of activists in anti-globalism movement. This research focuses the transition of 54 activists’ whole network in the “protest event” against 2008 G8 summit in Japan. Their network is examined at the three periods: Before protest event phase, during protest event phase and after event phase. A mixed method is used in this study: the author shows the hypothesis from social network analysis and evaluates that with interview data analysis. This analysis gives the two results. Firstly, the more protesters participate to the various events during the protest event, the more they build the network. After that, active protesters keep their network as well. From interview data, we can understand that the active protesters can build their network and diffuse the information because they communicate with other participants and understand that diverse issues are related. This paper comes to same conclusion with previous researches: protest events activate the network among the political activists. However, some participants succeed to build their network, others do not. “Networked” activists are participated in the various events for short period of time and encourage the diffusion of information and tactics of social movements.

Keywords: social movement, global justice movement, tactics, diffusion

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Authors: Geetha Baskaran, Andrzej Barjiela, Rong Qu

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Motivation: Nurse scheduling is a complex combinatorial optimization problem. It is also known as NP-hard. It needs an efficient re-scheduling to minimize some trade-off of the measures of violation by reducing selected constraints to soft constraints with measurements of their violations. Problem Statement: In this paper, we extend our novel approach to solve the nurse scheduling problem by transforming it through Information Granulation. Approach: This approach satisfies the rules of a typical hospital environment based on a standard benchmark problem. Generating good work schedules has a great influence on nurses' working conditions which are strongly related to the level of a quality health care. Domain transformation that combines the strengths of operation research and artificial intelligence was proposed for the solution of the problem. Compared to conventional methods, our approach involves judicious grouping (information granulation) of shifts types’ that transforms the original problem into a smaller solution domain. Later these schedules from the smaller problem domain are converted back into the original problem domain by taking into account the constraints that could not be represented in the smaller domain. An Integer Programming (IP) package is used to solve the transformed scheduling problem by expending the branch and bound algorithm. We have used the GNU Octave for Windows to solve this problem. Results: The scheduling problem has been solved in the proposed formalism resulting in a high quality schedule. Conclusion: Domain transformation represents departure from a conventional one-shift-at-a-time scheduling approach. It offers an advantage of efficient and easily understandable solutions as well as offering deterministic reproducibility of the results. We note, however, that it does not guarantee the global optimum.

Keywords: domain transformation, nurse scheduling, information granulation, artificial intelligence, simulation

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Authors: Fatemeh Rasooli, Behzad Simiari, Pooya Payandemehr, Amir Nejati, Maryam Bahreini, Atefeh Abdollahi

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Introduction: Pain is a complex physiological reaction to tissue injury. In the course of painful procedures such as nerve block, ice has been shown to be a feasible and inexpensive material to control pain. It delays nerve conduction, actives other senses and reduces inflammatory and painful responses. This study assessed the effect of ice in reducing pain caused by needling and infiltration during digital block. Patient satisfaction recorded as a secondary outcome. Methods: This study was designed as a non-blinded randomized clinical trial approved by Tehran University of Medical Sciences Ethical Committee. Informed consent was taken from all the participants who were then randomly divided into two groups. Digital block performed by standard approach in selected patients. Tubes of ice were prepared in gloves and were fragmented at a time of application for circling around the finger. Tubes were applied for 6 minutes before digital nerve block in the site of needling in the case group. Patients in the control group underwent digital nerve block with the conventional method without ice administration. Numeric Rating Scale (NRS) used for grading pain. 0 used for no pain and 10 for the worst pain that patient had experienced until now. Scores were analyzed by Wilcoxon Rank Sum test and compared in case and control groups. Results: 100 patients aged 16-50 years were enrolled. Mean NRS scores with and without ice were 1.5 mm (S.D ± 1.44) and 6.8 mm (S.D ± 1.40) for needling pain and for infiltration pain were 2.7mm ( S.D ±1.65) and 8.5mm ( S.D ± 1.47), respectively (p<0.001). Besides, patients’ satisfactions were significantly higher in the ice group (p<0.001). Conclusion: Application of ice for 6 minutes significantly reduced pain of needling and infiltration in digital nerve block; thus, it seems to be a feasible and inexpensive material which acts effectively to decrease pain and stress before the procedure.

Keywords: digital block, ice, needle, pain

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Authors: Predrag Kavaric, Vladimir L. Jubic, Maxim Cadenovic

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The patient was transferred from his dentist to our tertiary medical institution. In anamnesis, we got information that his dental intervention was two years ago when he got dental implants but because of the coronavirus pandemic event, he didn’t finish the whole procedure. After two years, he decided that he will continue his work at his dentist, then his dentist noticed that there is no earlier inserted implant in the upper jaw on the right side. They do Panoramic X-ray and find that the implant is all in the maxillary sinus cavity. The flour of the maxilla was intact without any fistula on the place where the implant was inserted in the maxilla bone, After that initial diagnostic they sent the patient to maxillofacial surgery and otorhinolaryngology. We asked for a CT scan of paranasal sinuses, which confirmed the foreign body in the right maxillary sinus. The plan was that in general anesthesia we do FESS and try to find a foreign body in the maxillary sinus or in case of failure to do Caldwel Luc on that side. After preoperative preparation in GA, we do FESS. In inspection, we find small polyps and chronically changed mucosa of osteomeatal complex and right maxillary sinus. After removing polyps we did uncinectomy and medial maxillectomy. With Heuweiser Antrum grasping forceps after several attempts we managed to extract a foreign body from the bottom of the right maxillary sinus. On the first postoperative day we did detamponade, and then we discharge the patient from hospital. The Covid pandemic has contributed to the postponement of a large number of planned operations, which has resulted in various complications in the treatment of a number of patients. In this case, it happened that the implant was most likely rejected by the bone but in the direction of the maxillary sinus, which is not a common cause. On the other hand, the success was that less traumatic intervention was able to remove the foreign body from the maxillary sinus in which it was located. Since the sinus floor is free of bone defects, it can be continued relatively quickly with dental procedures.

Keywords: x-ray, surgery, maxillar sinus, complication, fees

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Authors: Didier Auroux, Vladimir Groza

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This work is part of STEEP Marie-Curie ITN project, and it focuses on the identification of unknown parameters of the proposed generic Abrasive WaterJet Milling (AWJM) PDE model, that appears as an ill-posed inverse problem. The necessity of studying this problem comes from the industrial milling applications where the possibility to predict and model the final surface with high accuracy is one of the primary tasks in the absence of any knowledge of the model parameters that should be used. In this framework, we propose the identification of model parameters by minimizing a cost function, measuring the difference between experimental and numerical solutions. The adjoint approach based on corresponding Lagrangian gives the opportunity to find out the unknowns of the AWJM model and their optimal values that could be used to reproduce the required trench profile. Due to the complexity of the nonlinear problem and a large number of model parameters, we use an automatic differentiation software tool (TAPENADE) for the adjoint computations. By adding noise to the artificial data, we show that in fact the parameter identification problem is highly unstable and strictly depends on input measurements. Regularization terms could be effectively used to deal with the presence of data noise and to improve the identification correctness. Based on this approach we present results in 2D and 3D of the identification of the model parameters and of the surface prediction both with self-generated data and measurements obtained from the real production. Considering different types of model and measurement errors allows us to obtain acceptable results for manufacturing and to expect the proper identification of unknowns. This approach also gives us the ability to distribute the research on more complex cases and consider different types of model and measurement errors as well as 3D time-dependent model with variations of the jet feed speed.

Keywords: Abrasive Waterjet Milling, inverse problem, model parameters identification, regularization

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Authors: Adane Kassa Shikur

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Today’s supply chains (SC) have become vulnerable to unexpected and ever-intensifying disruptions from myriad sources. Consequently, the concept of supply chain resilience (SCRes) has become crucial to complement the conventional risk management paradigm, which has failed to cope with unexpected SC disruptions, resulting in severe consequences affecting SC performances and making business continuity questionable. Advancements in cutting-edge technologies like artificial intelligence (AI) and their potential to enhance SCRes by improving critical antecedents in the different phases have attracted the attention of scholars and practitioners. The research from academia and the practical interest of the industry have yielded significant publications at the nexus of AI and SCRes during the last two decades. However, the applications and examinations have been primarily conducted independently, and the extant literature is dispersed into research streams despite the complex nature of SCRes. To close this research gap, this study conducts a systematic literature review of 106 peer-reviewed articles by curating, synthesizing, and consolidating up-to-date literature and presents the state-of-the-art development from 2010 to 2022. Bayesian networks are the most topical ones among the 13 AI techniques evaluated. Concerning the critical antecedents, visibility is the first ranking to be realized by the techniques. The study revealed that AI techniques support only the first 3 phases of SCRes (readiness, response, and recovery), and readiness is the most popular one, while no evidence has been found for the growth phase. The study proposed an AI-SCRes framework to inform research and practice to approach SCRes holistically. It also provided implications for practice, policy, and theory as well as gaps for impactful future research.

Keywords: ANNs, risk, Bauesian networks, vulnerability, resilience

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Authors: Rudolf Hrach, Stanislav Novak, Vera Hrachova

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Composite and nanocomposite films represent the class of promising materials and are often objects of the study due to their mechanical, electrical and other properties. The most interesting ones are probably the composite metal/dielectric structures consisting of a metal component embedded in an oxide or polymer matrix. Behaviour of composite films varies with the amount of the metal component inside what is called filling factor. The structures contain individual metal particles or nanoparticles completely insulated by the dielectric matrix for small filling factors and the films have more or less dielectric properties. The conductivity of the films increases with increasing filling factor and finally a transition into metallic state occurs. The behaviour of composite films near a percolation threshold, where the change of charge transport mechanism from a thermally-activated tunnelling between individual metal objects to an ohmic conductivity is observed, is especially important. Physical properties of composite films are given not only by the concentration of metal component but also by the spatial and size distributions of metal objects which are influenced by a technology used. In our contribution, a study of composite structures with the help of methods of computational physics was performed. The study consists of two parts: -Generation of simulated composite and nanocomposite films. The techniques based on hard-sphere or soft-sphere models as well as on atomic modelling are used here. Characterizations of prepared composite structures by image analysis of their sections or projections follow then. However, the analysis of various morphological methods must be performed as the standard algorithms based on the theory of mathematical morphology lose their sensitivity when applied to composite films. -The charge transport in the composites was studied by the kinetic Monte Carlo method as there is a close connection between structural and electric properties of composite and nanocomposite films. It was found that near the percolation threshold the paths of tunnel current forms so-called fuzzy clusters. The main aim of the present study was to establish the correlation between morphological properties of composites/nanocomposites and structures of conducting paths in them in the dependence on the technology of composite films.

Keywords: composite films, computer modelling, image analysis, nanocomposite films

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Authors: Livia Herle

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A large part of the Principality of Liechtenstein is covered by forest. Three-quarters of this forest is defined as protective due to the alpine landscape of the country, which is deteriorating the quality of the wood. Nevertheless, the forest is one of the most important sources of raw material. However, out of the wood harvested annually in Liechtenstein, about two-thirds are used directly as an energy source, drastically shortening up the carbon storage cycle of wood. Furthermore, due to climate change, forest structures are changing. Predictions for the forest in Liechtenstein have stated that the spruce will mostly vanish in low altitudes, only being able to survive in the higher regions. In contrast, hardwood species will experience a rise, resulting in a more mixed forest. Thus, the main research focus will be put upon the potential of hardwood as well as prolonging the lifespan of a timber log before ending up as an energy source. An analysis of the local occurrence of hardwood species and their quality will serve as a tool to implement this knowledge upon constructional solutions. As a system that works with short spam timber and thus qualifies for the regional conditions of hardwood, reciprocal frame systems will be further investigated. These can be defined as load-bearing structures with only two beams connecting at a time, avoiding complex joining situations. Furthermore, every beam is mutually supporting. This allows the usage of short pieces of preferably massive wood. As a result, the system permits for an easy assembly but also disassembly. To promote a more circular application of wood, possible cascading scenarios of the structural solutions will be added. In a workshop at the School of Architecture of the University of Liechtenstein in the Sommer Semester 2024, prototypes in 1:1 of reciprocal frame systems using only local hardwood will help as a tool to further test the theoretical analyses.

Keywords: hardwood, cascading wood, reciprocal frames, crooked wood, forest structures, climate change

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Authors: Marina Benito-Parejo, Raul Perez-Lopez, Miguel Herraiz, Carolina Guardiola-Albert, Cesar Martinez

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Persistency, long-term memory and randomness are intrinsic properties of time-series of earthquakes. The Rescaled Range Analysis (RS-Analysis) was introduced by Hurst in 1956 and modified by Mandelbrot and Wallis in 1964. This method represents a simple and elegant analysis which determines the range of variation of one natural property (the seismic energy released in this case) in a time interval. Despite the simplicity, there is complexity inherent in the property measured. The cumulative curve of the energy released in time is the well-known fractal geometry of a devil’s staircase. This geometry is used for determining the maximum and minimum value of the range, which is normalized by the standard deviation. The rescaled range obtained obeys a power-law with the time, and the exponent is the Hurst value. Depending on this value, time-series can be classified in long-term or short-term memory. Hence, an algorithm has been developed for compiling the RS-Analysis for time series of earthquakes by days. Completeness time distribution and locally stationarity of the time series are required. The interest of this analysis is their application for a complex seismic crisis where different earthquakes take place in clusters in a short period. Therefore, the Hurst exponent has been obtained for the seismic crisis of Alhoceima (Mediterranean Sea) of January-March, 2016, where at least five medium-sized earthquakes were triggered. According to the values obtained from the Hurst exponent for each cluster, a different mechanical origin can be detected, corroborated by the focal mechanisms calculated by the official institutions. Therefore, this type of analysis not only allows an approach to a greater understanding of a seismic series but also makes possible to discern different types of seismic origins.

Keywords: Alhoceima crisis, earthquake time series, Hurst exponent, rescaled range analysis

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Authors: Hussien Ali, Mesfin Menza, Fitsum Hagos, Amare Haileslassie

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Climate change has perverse effects on agricultural productivity and natural resource base, negatively affecting the well-being of the households and communities. The government and NGOs promote climate smart agricultural (CSA) practices to help farmers adapt to and mitigate the negative effects of climate change. This study aims to identify widely available CSA practices and examine their impacts on food security and multi-dimensional poverty of rural farm households in the Central Rift Valley, Ethiopia. Using three-stage proportional to size sampling procedure, the study randomly selected 278 households from two kebeles from four districts each. A cross-sectional data of 2020/21 cropping season was collected using structured and pretested survey questionnaire. Food consumption score, dietary diversity score, food insecurity experience scale, and multidimensional poverty index were calculated to measure households’ welfare indicators. Multinomial endogenous switching regression model was used to assess average treatment effects of CSA on these outcome indicators on adopter and non-adopter households. The results indicate that the widely adopted CSA practices in the area are conservation agriculture, soil fertility management, crop diversification, and small-scale irrigation. Adopter households have, on average, statistically higher food consumption score, dietary diversity score and lower food insecurity access scale than non-adopters. Moreover, adopter households, on average, have lower deprivation score in multidimensional poverty compared to non-adopter households. Up scaling the adoption of CSA practices through the improvement of households’ implementation capacity and better information, technical advice, and innovative financing mechanisms is advised. Up scaling CSA practices can further promote achieving global goals such as SDG 1, SDG 2, and SDG 13 targets, aimed to end poverty and hunger and mitigate the adverse impacts of climate change, respectively.

Keywords: climate-smart agriculture, food security, multidimensional poverty, upscaling CSA, Ethiopia

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Authors: Ibrahim Aliyu Isah, Mohd Mansor Ismail, Salim Hassan, Norsida Man, Oluwatoyin Olagunju

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Stingless beekeeping is not only a profitable activity for Malaysian beekeepers but also for the Malaysian economy. However, natural honey has faced some difficulties, which resulted in low production due to a lack of information on improved technology as well as the capacity and potential building of stingless beekeeping farmers, which depend mostly on information received from the extension agents. Hence, it is the responsibility of the extension agents to give useful information on the available technology and develop the capacity of the farmers to make the right decision that will improve their level of production. This study assessed how technology transfer and human resource development skills influence the work performance of the extension agents toward sustainable beekeeping production among beekeepers. The study sought to establish the role of relevant technology transfer and human resource development skills in effective performance. The research design was a descriptive and quantitative survey of stingless beekeepers on technology transfer and human resource development by the extension agent. Data was obtained from 54 beekeeping farmers and was analyzed using descriptive and inferential statistics. The results revealed that technology skill, technology dissemination skill, technology evaluation skill, Decision-making process skill, Leadership development skill and work performance were rated moderate by stingless beekeeping farmers, while Social skill was rated high. A significant and positive correlation (P<0.01) existed between all variables and performance. Regression results showed that leadership development skills, Decision-making process skills, and social skills are significant (P=.05), while technology skills, technology dissemination skills, and technology evaluation skills are not significant. The highest contributing factor is social skill (β=.446). Beekeeping is a profitable project in Malaysia and can be sustained if the extension services and programs are well carried out by competent extension agents and relevant agricultural government agencies.

Keywords: beekeeping, extension agents, human resource development, sustainable, technology transfer, work performance

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Authors: Shreyas Srinivas Rangan, Jurgis Porins

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The internet traffic has increased exponentially due to the high demand for data rates by the users, and the constantly increasing metro networks and access networks are focused on improving the maximum transmit distance of the long-reach optical networks. One of the common methods to improve the maximum transmit distance of the long-reach optical networks at the component level is to use broadband optical amplifiers. The Erbium Doped Fiber Amplifier (EDFA) provides high amplification with low noise figure but due to the characteristics of EDFA, its operation is limited to C-band and L-band. In contrast, the Raman amplifier exhibits a wide amplification spectrum, and negative noise figure values can be achieved. To obtain such results, high powered pumping sources are required. Operating Raman amplifiers with such high-powered optical sources may cause fire hazards and it may damage the optical system. In this paper, we implement a hybrid optical amplifier configuration. EDFA and Raman amplifiers are used in this hybrid setup to combine the advantages of both EDFA and Raman amplifiers to improve the reach of the system. Using this setup, we analyze the maximum transmit distance of the network by obtaining a correlation diagram between the length of the single-mode fiber (SMF) and the Bit Error Rate (BER). This hybrid amplifier configuration is implemented in a Wavelength Division Multiplexing (WDM) system with a BER of 10⁻⁹ by using NRZ modulation format, and the gain uniformity noise ratio (signal-to-noise ratio (SNR)), the efficiency of the pumping source, and the optical signal gain efficiency of the amplifier are studied experimentally in a mathematical modelling environment. Numerical simulations were implemented in RSoft OptSim simulation software based on the nonlinear Schrödinger equation using the Split-Step method, the Fourier transform, and the Monte Carlo method for estimating BER.

Keywords: Raman amplifier, erbium doped fibre amplifier, bit error rate, hybrid optical amplifiers

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Authors: Mahsa Fathollahzadeh

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The various nanoparticles employed in drug delivery applications include micelles, liposomes, solid lipid nanoparticles, polymeric nanoparticles, functionalized nanoparticles, nanocrystals, cyclodextrins, dendrimers, and nanotubes. Micelles, composed of amphiphilic block copolymers, can encapsulate hydrophobic molecules, allowing for targeted delivery. Liposomes, vesicular structures made up of phospholipids, can encapsulate both hydrophobic and hydrophilic molecules, providing a flexible platform for delivering therapeutic agents. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) are designed to improve the stability and bioavailability of lipophilic drugs. Polymeric nanoparticles, such as poly(lactic-co-glycolic acid) (PLGA), are biodegradable and can be engineered to release drugs in a controlled manner. Functionalized nanoparticles, coated with targeting ligands or antibodies, can specifically target diseased cells or tissues. Nanocrystals, engineered to have specific surface properties, can enhance the solubility and bioavailability of poorly soluble drugs. Cyclodextrins, doughnut-shaped molecules with hydrophobic cavities, can be complex with hydrophobic molecules, allowing for improved solubility and bioavailability. Dendrimers, branched polymers with a central core, can be designed to deliver multiple therapeutic agents simultaneously. Nanotubes and metallic nanoparticles, such as gold nanoparticles, offer real-time tracking capabilities and can be used to detect biomolecular interactions. The use of these nanoparticles has revolutionized the field of drug delivery, enabling targeted and controlled release of therapeutic agents, reduced toxicity, and improved patient outcomes.

Keywords: nanotechnology, nanopharmaceuticals, drug-delivery, proteins, ligands, nanoparticles, chemistry

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Authors: G. Gevorgyan, S. Khudaverdyan, A. Vaseashta

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The Lake Sevan basin is situated in the eastern part of the Republic of Armenia (Gegharquniq marz/district). The heavy metal pollution of the some tributaries of Lake Sevan was investigated. Water sampling was performed in August and December, 2014 from the 4 observation sites: 1) Sotq river upstream (about 600 meters upstream from the Sotq gold mine); 2) Sotq river mouth; 3) Masrik river mouth; 4) Dzknaget river mouth. Heavy metal (V, Fe, Ni, Cu, As, Mo, Pb) concentrations in the water samples were determined by the standard methods using an atomic absorption spectrophotometer. The results of the study showed that heavy metal content mainly increased from the upstream of the Sotq river to the mouth of the Masrik river which may have been conditioned by the influence of gold mining activity as the Masrik and its tributary-Sotq rivers passing through the gold mining area were exposed to heavy metal pollution. The observation sites can be ranked by pollution degree as follows: №3> №2> №1> №4. The highest heavy metal pollution degree was observed in the Masrik river mouth which may have been conditioned by the direct impact of gold mining activity and the pressure of its tributary–the Sotq river which flows through the gold mining area. The lowest heavy metal pollution degree was registered in the Dzknaget river mouth which flowing through rural areas wasn’t subject to significant heavy metal pollution. According to the observation sites of the Sotq and Masrik rivers, high positive correlation was mainly observed between the concentrations of the investigated heavy metals (except nickel) which indicated that all the heavy metals except the nickel had the same anthropogenic pollution source which was the activity of the Sotq gold mine. In general, it is possible to state that the activity of the Sotq gold mine in the Lake Sevan basin caused the heavy metal pollution of the Sotq and Masrik rivers which may have posed environmental hazards. Heavy metals are nondegradable substances, and heavy metal pollution of freshwater systems may pose risks to the environment and human health through accumulation in the tissues of aquatic organisms, water-food chain as well as oral ingestion and dermal contact.

Keywords: Armenia, Lake Sevan basin, gold mining activity, river ecosystems, heavy metal pollution

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Authors: Zahra Khodaee

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Background and Objective: The attractive potential for tourism in the southern islands of Iran, Kish, and Qeshm and recently Hendurabi, are becoming more and more popular and object of increased attention from the investors. The Iranian coral reef islands, with the exception of Kish and Qeshm, have not undergone sufficient development. The southern islands of Iran have faced two problems with climate change and the desire for the presence of tourists. The lack of proper planning, inefficient management, and lack of adequate knowledge of ecosystems of offshore regions have severely damaged the world natural heritage. This study was conducted to consider the correlation of tourism, development, and ecosystem because there is a need for further addressing the ecotourism in coral islands. Method: Through qualitative research, this paper was used of library studies and field studies and surveying to study the physical (objective-subjective) physical factors of ecotourism development in Honduran Island. Using SPSS software and descriptive-analytical method was shown the results. The survey was conducted with the participation of 150 tourists on Kish islands, who were chosen at random and who expressed their desire to travel to Hendurabi Island. Information was gathered using SPSS software and unique statistical T-test. The questionnaire was put together using AMOS software to ensure that the questions asked were sufficiently relevant. Findings: The results of this study presented that physical factors affecting the development of ecotourism in two categories are objective and subjective factors because IFI factor = 0.911 and CFI Factor = 0.907 into the target community. Discussion and conclusion: The results were satisfactory in that they showed that eco-tourists attached importance to see views, quiet, secluded areas, tranquility security, quality of the area being visited, easy access to services these were the top criteria for those visiting the area while they adhere to environmental compliance. Developing Management of these regions should maintain appropriate utilization along with sustainable and ecological responsibility.

Keywords: ecotourism, coral reef island, development management, Hendurabi Island

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Authors: Ali Mahfouz

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Egypt's cultural heritage and artistic riches find themselves at a complex intersection of preservation and urban development, where they face intricate challenges exacerbated by climate change, pollution, urbanization, and construction activities. In this research, it delves into the multifaceted dynamics involved in conserving Egypt's heritage within urban contexts, spotlighting the historic Cairo cemetery as a poignant and timely case study. The historic Cairo cemetery serves as a repository of priceless cultural assets, housing the final resting places of public figures, artists, historians, politicians, and other luminaries. These graves are adorned with magnificent artworks and rare tombstones, collectively representing an irreplaceable slice of Egypt's history and culture. Yet, the looming threat of demolition to make way for new infrastructure projects underscores the delicate equilibrium that preservation efforts must maintain in the face of urban development pressures. This paper illuminates the collaborative efforts of historians, intellectuals, and civil society organizations who are determined to forestall the destruction of this invaluable cultural heritage. Their initiatives, driven by a shared commitment to documenting and safeguarding the cemetery's treasures, underscore the urgent imperative of protecting Egypt's cultural legacy. Through this case study, It gain insights into how Egypt navigates the challenges of preserving its rich heritage amidst urban expansion and a changing climate, emphasizing the broader importance of heritage conservation in an evolving world.

Keywords: Egypt’s cultural heritage, urban development, historic Cairo cemetery, tombstone artworks, demolition threat, heritage conservation, civil society initiatives

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Authors: Kanokwan Tangchitnusorn, Patcharawalai Wongboonsin

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Following the ‘Golden Age of Welfare’ which enabled post-war prosperity to European citizens in 1950s, the world has witnessed the increasing mobility across borders of older citizens of First World countries. Then, in 1990s, the international retirement migration (IRM) of older persons has become a prominent trend, in which, it requires the integration of several fields of knowledge to explain, i.e. migration studies, tourism studies, as well as, social gerontology. However, while the studies of the IRM to developed destinations in Europe (e.g. Spain, Malta, Portugal, Italy), and the IRM to developing countries like Mexico, Panama, and Morocco have been largely studied in recent decades due to their massive migration volume, the study of the IRM to remoter destinations has been far more relatively sparse and incomplete. Developing countries in Southeast Asia have noticed the increasing number of retired expats, particularly to Thailand, where the number of foreigners applying for retirement visa increased from 10,709 in 2005 to 60,046 in 2014. Additionally, it was evident that the majority of Thailand’s retirement visa applicants were Westerners, i.e. citizens of the United Kingdom, the United States, Germany, and the Nordic countries, respectively. As such trend just becoming popular in Thailand in recent decades, little is known about the IRM populations, their well-being, and their future migration plans. This study aimed to examine the subjective wellbeing or the self-evaluations of own well-being among Western retirees in Thailand, as well as, their future migration plans as whether they planned to stay here for life or otherwise. The author employed a mixed method to obtain both quantitative and qualitative data during October 2015 – May 2016, including 330 self-administered questionnaires (246 online and 84 hard-copied responses), and 21 in-depth interviews of the Western residents in Nan (2), Pattaya (4), and Chiang Mai (15). As derived from the integration of previous subjective well-being measurements (i.e. Personal Wellbeing Index (PWI), Global AgeWatch Index, and OECD guideline on measuring subjective wellbeing), this study would measure the subjective well-being of Western retirees in Thailand in 7 dimensions, including standard of living, health status, personal relationships, social connections, environmental quality, personal security and local infrastructure.

Keywords: international retirement migration, ageing, mobility, wellbeing, Western, Thailand

Procedia PDF Downloads 328

Authors: Nihal Kartaltepe Behram, Göksel Ataman, Dila Okçu

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With the development of foreign direct investments, the social, cultural, political and economic interactions between countries and institutions have become visible and they have become determining factors for the strategic structuring and market goals. In this context the purpose of this study is to investigate the effects of cultural distance and institutions on foreign direct investment choices in terms of location and investment model. For international establishments, the concept of culture, as well as the concept of cultural distance, is taken specifically into consideration, especially in the selection of methods for entering the market. In the researches and empirical studies conducted, a direct relationship between cultural distance and foreign direct investments is set and institutions and effective variable factors are examined at the level of defining the investment types. When the detailed calculation strategies and empirical researches and studies are taken into consideration, the most common methods for determining the direct investment model, considering the cultural distances, are full-ownership enterprises and joint ventures. Also, when all of the factors affecting the investments are taken into consideration, it was seen that the effect of institutions such as Government Intervention, Intellectual Property Rights, Corruption and Contract Enforcements is very important. Furthermore agglomeration is more intense and effective on the investment, compared to other factors. China has been selected as the target country, due to its effectiveness in world economy and its contributions to developing countries, which has commercial relationships with. Qualitative research methods are used for this study conducted, to measure the effects of determinative variable factors in the hypotheses of study, on the direct foreign investors and to evaluate the findings. In this study in-depth interview is used as a data collection method and the data analysis is made through descriptive analysis. Foreign Direct Investments are so reactive to institutions and cultural distance is identified by all interviews and analysis. On the other hand, agglomeration is the most strong determiner factor on foreign direct investors in Chinese Market. The reason of this factors, which comprise the sectorial aggregate, are not the strongest factors as agglomeration that the most important finding. We expect that this study became a beneficial guideline for developed and developing countries and local and national institutions’ strategic plans.

Keywords: China, cultural distance, Foreign Direct Investments, institutions

Procedia PDF Downloads 404

Authors: Rahul R. Gurpude, Pallvita Yadav, Amrut Mulay

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In recent years, there has been a growing focus on advanced manufacturing processes, and one such emerging process is wire electric discharge machining (WEDM). WEDM is a precision machining process specifically designed for cutting electrically conductive materials with exceptional accuracy. It achieves material removal from the workpiece metal through spark erosion facilitated by electricity. Initially developed as a method for precision machining of hard materials, WEDM has witnessed significant advancements in recent times, with numerous studies and techniques based on electrical discharge phenomena being proposed. These research efforts and methods in the field of ED encompass a wide range of applications, including mirror-like finish machining, surface modification of mold dies, machining of insulating materials, and manufacturing of micro products. WEDM has particularly found extensive usage in the high-precision machining of complex workpieces that possess varying hardness and intricate shapes. During the cutting process, a wire with a diameter ranging from 0.18mm is employed. The evaluation of EDM performance typically revolves around two critical factors: material removal rate (MRR) and surface roughness (SR). To comprehensively assess the impact of machining parameters on the quality characteristics of EDM, an Analysis of Variance (ANOVA) was conducted. This statistical analysis aimed to determine the significance of various machining parameters and their relative contributions in controlling the response of the EDM process. By undertaking this analysis, optimal levels of machining parameters were identified to achieve desirable material removal rates and surface roughness.

Keywords: WEDM, MRR, optimization, surface roughness

Procedia PDF Downloads 62

Authors: Sze Wing Ho, Nagendra P. Shah

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Lactic acid bacteria (LAB) have shown the beneficial effects on human gastrointestinal tract, such as protects diarrhea induced by lactose intolerance or enteric pathogens. Citrulline is a non-protein amino acid and also the precursors of arginine and nitric oxide, it has shown to enhance intestinal barrier function. Citrulline has shown to improve the growth of some strains of LAB, it is important for LAB to have a sufficient cell concentration to contribute the effects. Therefore, the aims of this study were to investigate the effect of combining citrulline with LAB on the anti-adhesion effect against pathogens and the effect on the cell integrity. The effect of citrulline on selected LAB was determined by incubating in 0%, 0.1% or 0.2% citrulline enriched MRS broth for 18 h. The adhesion ability of LAB and the anti-adhesion effect of LAB and citrulline against pathogens were performed on IPEC-J2 cell line. Transepithelial electrical resistance (TEER) assay was used to measure the tight junction (TJ) integrity. TJ proteins (claudin-1, occludin and zonula occluden-1 (ZO-1)) were determined by western blot analysis. It found that the growth of Lactobacillus helveticus ASCC 511 was significantly stimulated by 0.2% citrulline compared with control during 18 h fermentation. The adhesion of L. helveticus ASCC 511 and Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) ASCC 756 was increased when supplemented with citrulline. Citrulline has shown significant inhibitory effect on the adhesion of Escherichia coli PELI0480 (O157:H7), Shigella sonnei ATCC 25931, Staphyloccocus aureus CMCC26003 and Cronobacter sakazakii ATCC 29544. The anti-adhesion effect of L. helveticus ASCC 511, L. bulgaricus ASCC 756 and Lactobacillus paracasei ASCC 276 against Cronobacter sakazakii ATCC 29544 was significantly enhanced with citrulline supplementation. Treatments with citrulline and LAB were able to maintain the TEER of IPEC-J2 cell and shown the positive effect on the TJ proteins. In conclusion, citrulline had stimulating effect on some strains of LAB and determined to improve the adhesion of LAB on intestinal epithelial cell, to enhance the inhibitory effect on enteric pathogens adhesion as well as had beneficial effects on maintaining cell integrity. It implied LAB supplemented with citrulline might have advantageous effects on gastrointestinal tracts.

Keywords: citrulline, lactic acid bacteria, amino acid, anti-adhesion effect, cell integrity

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Authors: Archana Gupta, Rajesh Kumar

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The chemistry of chalcones has generated intensive scientific studies throughout the world. Especially, interest has been focused on the synthesis and biodynamic activities of chalcones. The blue light transmittance, excellent crystallizability and the two planar rings connected through a conjugated double bond show that chalcone derivatives are superior nonlinear organic compounds. 3-(2-Chloro-6-fluoro¬phen¬yl)-1-(2-thien¬yl) prop-2-en-1-one, 3-(2, 4- Dichlorophenyl) – 1 - (4-methylphenyl) – prop -2-en-1-one, (2E)-3-[4-(methylsulfanyl) phenyl]-1-(4-nitrophenyl) prop-2-en-1-one are some chalcone derivatives exhibiting non linear optical (NLO) properties. NLO materials have been extensively investigated in recent years as they are the key elements for photonic technologies of optical communication, optical interconnect oscillator, amplifier, frequency converter etc. Due to their high molecular hyperpolarizabilities, organic materials display a number of significant NLO properties. Experimental measurements and theoretical calculations on molecular hyperpolarizability β have become one of the key factors in the design of second order NLO materials. Theoretical determination of hyperpolarizability is quite useful both in understanding the relationship between the molecular structure and NLO properties. It also provides a guideline to experimentalists for the design and synthesis of organic NLO materials. Quantum-chemical calculations have made an important contribution to the understanding of the electronic polarization underlying the molecular NLO processes and the establishment of structure–property relationships. In the present investigation, the detailed vibrational analysis of some chalcone derivatives is taken up to understand the correlation of the charge transfer interaction and the NLO activity of the molecules based on density functional theory calculations. The vibrational modes contributing toward the NLO activity have been identified and analyzed. Rather large hyperpolarizability derived by theoretical calculations suggests the possible future use of these compounds for non-linear optical applications. The study suggests the importance of π - conjugated systems for non-linear optical properties and the possibility of charge transfer interactions. We hope that the results of the present study of chalcone derivatives are of assistance in development of new efficient materials for technological applications.

Keywords: hyperpolarizability, molecular structure, NLO material, quantum chemical calculations

Procedia PDF Downloads 221

Authors: Alemayehu Muluneh, Saskia Keesstra, Leo Stroosnijder, Woldeamlak Bewket, Ashenafi Burka

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There are some scientific evidences and a belief by many that forests attract rain and deforestation contributes to a decline of rainfall. However, there is still a lack of concrete scientific evidence on the role of forests in rainfall amount. In this paper, we investigate the forest-rainfall relationships in the environmentally hot spot area of the Central Rift Valley (CRV) of Ethiopia. Specifically, we evaluate long term (1970-2009) rainfall variability and its relationship with historical forest cover and the relationship between existing forest cover and topographical variables and rainfall distribution. The study used 16 long term and 15 short term rainfall stations. The Mann-Kendall test, bi variate and multiple regression models were used. The results show forest and wood land cover continuously declined over the 40 years period (1970-2009), but annual rainfall in the rift valley floor increased by 6.42 mm/year. But, on the escarpment and highlands, annual rainfall decreased by 2.48 mm/year. The increase in annual rainfall in the rift valley floor is partly attributable to the increase in evaporation as a result of increasing temperatures from the 4 existing lakes in the rift valley floor. Though, annual rainfall is decreasing on the escarpment and highlands, there was no significant correlation between this rainfall decrease and forest and wood land decline and also rainfall variability in the region was not explained by forest cover. Hence, the decrease in annual rainfall on the escarpment and highlands is likely related to the global warming of the atmosphere and the surface waters of the Indian Ocean. Spatial variability of number of rainy days from systematically observed two-year’s rainfall data (2012-2013) was significantly (R2=-0.63) explained by forest cover (distance from forest). But, forest cover was not a significant variable (R2=-0.40) in explaining annual rainfall amount. Generally, past deforestation and existing forest cover showed very little effect on long term and short term rainfall distribution, but a significant effect on number of rainy days in the CRV of Ethiopia.

Keywords: elevation, forest cover, rainfall, slope

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