Search results for: demographic and geographic condition

Authors: Maryam Hasanali, Syed Mohammad Mojtabaei, Iman Hajirasouliha, G. Charles Clifton, James B. P. Lim

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Cold-formed steel (CFS) elements are increasingly being used as main load-bearing components in the modern construction industry, including low- to mid-rise buildings. In typical multi-storey buildings, CFS structural members act as beam-column elements since they are exposed to combined axial compression and bending actions, both in moment-resisting frames and stud wall systems. Current design specifications, including the American Iron and Steel Institute (AISI S100) and the Australian/New Zealand Standard (AS/NZS 4600), neglect the beneficial effects of warping-restrained boundary conditions in the design of beam-column elements. Furthermore, while a non-linear relationship governs the interaction of axial compression and bending, the combined effect of these actions is taken into account through a simplified linear expression combining pure axial and flexural strengths. This paper aims to evaluate the reliability of the well-known Direct Strength Method (DSM) as well as design proposals found in the literature to provide a better understanding of the efficiency of the code-prescribed linear interaction equation in the strength predictions of CFS beam columns and the effects of warping-restrained boundary conditions on their behavior. To this end, the experimentally validated finite element (FE) models of CFS elements under compression and bending were developed in ABAQUS software, which accounts for both non-linear material properties and geometric imperfections. The validated models were then used for a comprehensive parametric study containing 270 FE models, covering a wide range of key design parameters, such as length (i.e., 0.5, 1.5, and 3 m), thickness (i.e., 1, 2, and 4 mm) and cross-sectional dimensions under ten different load eccentricity levels. The results of this parametric study demonstrated that using the DSM led to the most conservative strength predictions for beam-column members by up to 55%, depending on the element’s length and thickness. This can be sourced by the errors associated with (i) the absence of warping-restrained boundary condition effects, (ii) equations for the calculations of buckling loads, and (iii) the linear interaction equation. While the influence of warping restraint is generally less than 6%, the code suggested interaction equation led to an average error of 4% to 22%, based on the element lengths. This paper highlights the need to provide more reliable design solutions for CFS beam-column elements for practical design purposes.

Keywords: beam-columns, cold-formed steel, finite element model, interaction equation, warping-restrained boundary conditions

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Authors: Huimin Liu, Li Xiang, Yue Liu, Jing Wang

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Background: As one of typical case for the developing countries who are stepping into the aging times globally, more and more older people in China might face the problem of which they could not maintain normal life due to the functional disability. While the government take efforts to build long-term care system and further carry out related policies for the core concept, there is still lack of strong evidence to evaluating the profile of disability states in the elderly population and its transition rate. It has been proved that disability is a dynamic condition of the person rather than irreversible so it means possible to intervene timely on them who might be in a risk of severe disability. Objective: The aim of this study was to depict the picture of the disability transferring status of the older people in China, and then find out individual characteristics that change the state of disability to provide theory basis for disability prevention and early intervention among elderly people. Methods: Data for this study came from the 2011 baseline survey and the 2013 follow-up survey of the China Health and Retirement Longitudinal Study (CHARLS). Normal ADL function, 1~2 ADLs disability,3 or above ADLs disability and death were defined from state 1 to state 4. Multi-state Markov model was applied and the four-state homogeneous model with discrete states and discrete times from two visits follow-up data was constructed to explore factors for various progressive stages. We modeled the effect of explanatory variables on the rates of transition by using a proportional intensities model with covariate, such as gender. Result: In the total sample, state 2 constituent ratio is nearly about 17.0%, while state 3 proportion is blow the former, accounting for 8.5%. Moreover, ADL disability statistics difference is not obvious between two years. About half of the state 2 in 2011 improved to become normal in 2013 even though they get elder. However, state 3 transferred into the proportion of death increased obviously, closed to the proportion back to state 2 or normal functions. From the estimated intensities, we see the older people are eleven times as likely to develop at 1~2 ADLs disability than dying. After disability onset (state 2), progression to state 3 is 30% more likely than recovery. Once in state 3, a mean of 0.76 years is spent before death or recovery. In this model, a typical person in state 2 has a probability of 0.5 of disability-free one year from now while the moderate disabled or above has a probability of 0.14 being dead. Conclusion: On the long-term care cost considerations, preventive programs for delay the disability progression of the elderly could be adopted based on the current disabled state and main factors of each stage. And in general terms, those focusing elderly individuals who are moderate or above disabled should go first.

Keywords: Markov model, elderly people, disability, transition intensity

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Authors: Sumanta Daw, Gopal Chandra Saha

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The present study was conducted to explore the basic pulmonary functions which may generally vary according to the bio-physical characteristics including age, height, body weight, and environment etc. of the sports performers. Regular and specific training exercises also change the characteristics of an athlete’s prowess and produce a positive effect on the physiological functioning, mostly upon cardio-pulmonary efficiency and thereby improving the body mechanism. The objective of the present study was to compare the differences in cardio-respiratory functions between aquatics and track and field performers. As cardio-respiratory functions are influenced by pulse rate and blood pressure (systolic and diastolic), so both of the factors were also taken into consideration. The component selected under cardio-respiratory functions for the present study were i) FEVI/FVC ratio (forced expiratory volume divided by forced vital capacity ratio, i.e. the number represents the percentage of lung capacity to exhale in one second) ii) FVC1 (this is the amount of air which can force out of lungs in one second) and iii) FVC (forced vital capacity is the greatest total amount of air forcefully breathe out after breathing in as deeply as possible). All the three selected components of the cardio-respiratory efficiency were measured by spirometry method. Pulse rate was determined manually. The radial artery which is located on the thumb side of our wrist was used to assess the pulse rate. Blood pressure was assessed by sphygmomanometer. All the data were taken in the resting condition. 36subjects were selected for the present study out of which 18were water polo players and rest were sprinters. The age group of the subjects was considered between 18 to 23 years. In this study the obtained data inform of digital score were treated statistically to get result and draw conclusions. The Mean and Standard Deviation (SD) were used as descriptive statistics and the significant difference between the two subject groups was assessed with the help of statistical ‘t’-test. It was found from the study that all the three components i.e. FEVI/FVC ratio (p-value 0.0148 < 0.01), FVC1 (p-value 0.0010 < 0.01) and FVC (p-value 0.0067 < 0.01) differ significantly as water polo players proved to be better in terms of cardio-respiratory functions than sprinters. Thus study clearly suggests that the exercise training as well as the medium of practice arena associated with water polo players has played an important role to determine better cardio respiratory efficiency than track and field athletes. The outcome of the present study revealed that the lung function in land-based activities may not provide much impact than that of in water activities.

Keywords: cardio-respiratory efficiency, spirometry, water polo players, sprinters

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Authors: Chamaraja Parulli

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Family is an important social institution devoted to the growth of a child, and parents are the important agents of socialization. Mentally challenged children are those who are affected by intellectual disability, which is manifested by limitation in intellectual functioning and adoptive behavior. Intellectual disability affects about 3-4 percentage of the general population. Intellectual disability is caused by genetic condition, problems during pregnancy, problems during childbirth, or illness. Mental retardation is the world’s most complex and challenging issue. The stigmatization of disability results in social and economic marginalization. Parents of the mentally challenged children will have a very high level of parenting stress, which is significantly more than the stress perceived by the parents of the children without disability. The prevalence of severe mental disorder called Schizophrenia is among 1.1 percent of the total population in India. On the other hand, 11 to 12 percent is the overall lifetime occurrence rate of mental disorders. While the government has a separate program for mental health, the segment is marred by lack of adequate doctors and infrastructure. Mentally retarded children have certain limitations in mental functioning and skills, which makes them slow learners in speaking, walking, and taking care of their personal needs such as dressing and eating. Accepting a child with mental handicap becomes difficult for parents and to the whole family, as they have to face many problems, including those of management, finance, deprivation of rest, and leisure. Also, the problems faced by the parents can be seen in different areas like – educational, psychological, social, emotional, financial and family related issues. The study brought out various difficulties and problems faced by the parents as well as family members. The findings revealed that the mental retardation is not only a medico-psychological problem but also a socio-cultural problem. The study results, however, indicate that the quality of life of the family having children with mental retardation can be improved to a greater extent by building up a child-friendly ambience at home. The main aim of the present study is to assess the problems faced by the parents of mentally challenged children, with the help of personal interview data collected from the parents of mentally challenged children, residing in Shimoga District of Karnataka State, India. These individuals were selected using stratified random sampling method. Organizing effective intervention programs for parents, family, society, and educational institutions towards reduction of family stress, augmenting the family’s strengths, increasing child’s competence and enhancing the positive attitudes and values of the society will go a long way for the peaceful existence of the mentally challenged children.

Keywords: mentally challenged children, intellectual disability, special children, social infrastructure, differently abled, psychological stress, marginalization

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Authors: Birgit Rasmussen, Thomas Maribo, Bente S. Toft

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BACKGROUND: Cardiac rehabilitation is the standard treatment for ischemic heart disease. Cardiac rehabilitation improves quality of life, reduces mortality and the risk of readmission, and provides patients with valuable knowledge and encouragement from peers and staff. Still, less than half of eligible patients enroll. Face-to-face interventions have the potential to support patients' decision-making and increase enrolment in cardiac rehabilitation. However, we lack knowledge of the content and characteristics of interventions. AIM: The aim was to outline and evaluate the content and characteristics of studies that have reported on face-to-face interventions to encourage enrolment in cardiac rehabilitation in patients with ischemic heart disease. METHOD: This scoping review followed the Joanne Briggs Institute methodology. Based on an a-priori protocol that defined the systematic search criteria, six databases were searched for studies published between 2001 and 2023. Two reviewers independently screened and selected studies. All authors discussed the summarized data prior to the narrative presentation. RESULTS: After screening and full text review of 5583 records, 20 studies of heterogeneous design and content were included. Four studies described the key contents in face-to-face interventions to be education, support of autonomy, addressing reasons for change, and emotional and cognitive support while showing understanding. Two studies used motivational interviewing to target patients' experiences and address worries and anticipated difficulties. Four quantitative studies found associations between enrolment and intention to attend, cardiac rehabilitation barriers, exercise self-efficacy, and perceived control. When patients asked questions, enrolment rates were higher, while providing reassurance and optimism could lead to non-attendance if patients had a high degree of worry. In qualitative studies, support to overcome barriers and knowledge about health benefits from participation in cardiac rehabilitation facilitated enrolment. Feeling reassured that the cardiac condition was good could lead to non-attendance. DISCUSSION AND CONCLUSION: To support patients' enrolment in cardiac rehabilitation, it is recommended that interventions integrate a person-centered dialogue. Individual worries and barriers to cardiac rehabilitation should be jointly explored. When talking with patients for whom worries predominate, the recommendation is to focus on the patients' perspectives and avoid too much focus on reassurance and problem-solving. The patients' perspectives, the mechanisms of change, and the process evaluation of the intervention including person-centeredness are relevant to include in future studies.

Keywords: ischemic heart disease, cardiac rehabilitation, enrolment, person-centered, in-hospital interventions

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Authors: Jirapan Khruesarn, Wimwipa Boonklin

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Background: Currently, Thailand has an aging population. In 2017, the elderly population was over 11.14 million. There will be an increase in the number of elderly people, 8.39 million, some people grumble to themselves and have conflicts with their offspring or those close to them. It is a source of stress. Mental health promotion should be given to the elderly in order to cope with these changes. Due to the family characteristics of Thai society, these family members will act as caregivers for the elderly. Therefore, a group-counseling program based on Personnel-Centered Theory for Elderly Caregivers in Mental Health Promotion for Older People in Na Kaeo Municipality, Kau Ka District, Lampang Province, has been developed to compare the elderly care behavior before and after the participation. Methods: This research was study for 20 elderly' caregiver: Those aimed to compare the before and after use of group program for caregiver to promoting for the elderly by the following methods: Step 1 Establish a framework for evaluating elderly care behaviors and develop a group counseling program for promote mental health for elderly on: 1) Body 2) Willpower 3) Social and community management and 4) Organizing learning process. Step 2 Assessing an Elderly Care Behaviors by using "The behavior assessment on caring for the elderly" and assessing the mental health power level of the elderly and follow the counseling program 9 times and compare of the elderly care behaviors before and after joined a group program, and compare of mental health level of caregiver attends a group program. Results: This study is developing a group counseling program to promoting for the resilience quotient in elderly people that the results of the study could be summarized as follows: 1) Before the elderly's caregivers join a group counseling program: Mental health promotion behaviors of the elderly were at the high level of (3.32), and after: were at the high level of (3.44). 2) Before the elderly's caregiver attends a group counseling program: the mental health level of the elderly the mean score was (47.85 percent), and the standard deviation was (0.21 percent) and after. The elderly had a higher score of (51.45 percent) In summary, after the elderly caregivers joined the group, the elderly are higher in all aspects promote mental health for elderly and the statistically significance at the 0.05, It shows that programs are fit for personal and community condition in promoting the mental health of the elderly because this theory has the idea that: Humans have the ability to use their intelligence to solve problems or make decisions effectively, And member of group counseling program have ventured and express grievances that the counselor is a facilitator who focuses on personal development by building relationships among people. In other words, the factors contributing to higher levels of elderly care behaviors is group counseling, that isn't a hypothetical process but focus on building relationships that are based on mutual trust and Unconditional acceptance.

Keywords: group counseling base on person-centered theory, elderly person, resilience quotient: RQ, caregiver

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Authors: Fahimeh Ghorbani, Alam Saleh

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Ideology, politics and art have always been omnipresent patterns of Islam since its early age. The Islamic empire, expanded from China to Andalusia, has instrumentalized art and architecture to enhance political legitimacy of different dynasties or states throughout its history. Quranic verses utilized to convey ideological messages in the major mosques and mausoleums. Iranians had already been employing art and architecture to propagate their political legitimacy prior to Islam. The land of Iran and its art with strong civilizational pre-Islamic history has been profoundly politicized since the rise of Islam in the region. Early Islamic period in Iran has witnessed introduction of a new architectural language, new formulas for spatial configuration in built spaces, as well as new system of architectural decoration. Studying Iran’s Early Islamic architecture helps in better understanding the process of socio-political identity making of Iranian-Islamic culture, and thus art and architecture. This period also set the stage for formation of glorious architectural movements through Persianate world in later periods. During the Early Islamic period in Iran, the innovative combination of Islamic ideology and Iranian Architecture created formidable ideological tools in politicizing art in the region and beyond. As such, this paper aims to investigate the political history and architectural legacy from late Sassanid to Early Islamic period, delves into the ways in which Early Islamic architecture played role in transforming Persian concepts of kingship, administration, and social organization. In so doing, the study focuses on the Perso-Islamic architectural synthesis under the Samanids and Seljuk dynasty as case studies. The paper also explores how the newly introduced Islamic architecture has been employed to address the question of political legitimacy and to propagate states’ political agenda in early Islamic Iran (650-1250). As for the existing literature, despite its uniqueness and significance, Early Islamic architecture of Iran has received little scholarly attention. However, there exists a sizeable body of scholarship on socio-historic condition of the land of Iran during Early Islamic period which provide a solid base for the project. Methodologically speaking, the authors look into the subject through various lenses. They will conduct historic and archival research in libraries, private collections, and archives in Iran and the related neighbouring countries in Persian, Arabic and English. The methods of visual and formal analysis are applied to examine architectural features of the period. There are also a high number of intriguing, yet poorly examined, published and unpublished documents, old plans, drawings and photos of monuments preserved in Cultural Heritage of Iran Organization which will be consulted.

Keywords: Iran, Islamic architecture, early Islamic Iran, early Islamic architecture, politicized art, political legitimacy, propaganda, aesthetics

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Authors: Tathagatha Khan, Smruti Sourava Mohapatra

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Median openings are provided in raised median of multilane roads to facilitate U-turn movement. The U-turn movement is a highly complex and risky maneuver because U-turning vehicle (minor stream) makes 180° turns at median openings and merge with the approaching through traffic (major stream). A U-turning vehicle requires a suitable gap in the major stream to merge, and during this process, the possibility of merging conflict develops. Therefore, these median openings are potential hot spot of conflict and posses concern pertaining to safety. The traffic at the median openings could be managed efficiently with enhanced safety when the capacity of a traffic facility has been estimated correctly. The capacity of U-turns at median openings is estimated by Harder’s formula, which requires three basic parameters namely critical gap, follow up time and conflict flow rate. The estimation of conflicting flow rate under mixed traffic condition is very much complicated due to absence of lane discipline and discourteous behavior of the drivers. The understanding of placement of major stream vehicles at median opening is very much important for the estimation of conflicting traffic faced by U-turning movement. The placement data of major stream vehicles at different section in 4-lane and 6-lane divided multilane roads were collected. All the test sections were free from the effect of intersection, bus stop, parked vehicles, curvature, pedestrian movements or any other side friction. For the purpose of analysis, all the vehicles were divided into 6 categories such as motorized 2W, autorickshaw (3-W), small car, big car, light commercial vehicle, and heavy vehicle. For the collection of placement data of major stream vehicles, the entire road width was divided into sections of 25 cm each and these were numbered seriatim from the pavement edge (curbside) to the end of the road. The placement major stream vehicle crossing the reference line was recorded by video graphic technique on various weekdays. The collected data for individual category of vehicles at all the test sections were converted into a frequency table with a class interval of 25 cm each and the placement frequency curve. Separate distribution fittings were tried for 4- lane and 6-lane divided roads. The variation of major stream traffic volume on the placement characteristics of major stream vehicles has also been explored. The findings of this study will be helpful to determine the conflict volume at the median openings. So, the present work holds significance in traffic planning, operation and design to alleviate the bottleneck, prospect of collision and delay at median opening in general and at median opening in developing countries in particular.

Keywords: median opening, U-turn, conflicting traffic, placement, mixed traffic

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Authors: Marina Chavleishvili

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Introduction: Today, the study of monopolies, including natural monopolies, is topical. In real life, pure monopolies are natural monopolies. Natural monopolies are used widely and are regulated by the state. In particular, the prices and rates are regulated. The paper considers the problems associated with the operation of natural monopolies in Georgia, in particular, their microeconomic analysis, pricing mechanisms, and legal mechanisms of their operation. The analysis was carried out on the example of the power industry. The rates of natural monopolies in Georgia are controlled by the Georgian National Energy and Water Supply Regulation Commission. The paper analyzes the positive role and importance of the regulatory body and the issues of improving the legislative base that will support the efficient operation of the branch. Methodology: In order to highlight natural monopolies market tendencies, the domestic and international markets are studied. An analysis of monopolies is carried out based on the endogenous and exogenous factors that determine the condition of companies, as well as the strategies chosen by firms to increase the market share. According to the productivity-based competitiveness assessment scheme, the segmentation opportunities, business environment, resources, and geographical location of monopolist companies are revealed. Main Findings: As a result of the analysis, certain assessments and conclusions were made. Natural monopolies are quite a complex and versatile economic element, and it is important to specify and duly control their frame conditions. It is important to determine the pricing policy of natural monopolies. The rates should be transparent, should show the level of life in the country, and should correspond to the incomes. The analysis confirmed the significance of the role of the Antimonopoly Service in the efficient management of natural monopolies. The law should adapt to reality and should be applied only to regulate the market. The present-day differential electricity tariffs varying depending on the consumed electrical power need revision. The effects of the electricity price discrimination are important, segmentation in different seasons in particular. Consumers use more electricity in winter than in summer, which is associated with extra capacities and maintenance costs. If the price of electricity in winter is higher than in summer, the electricity consumption will decrease in winter. The consumers will start to consume the electricity more economically, what will allow reducing extra capacities. Conclusion: Thus, the practical realization of the views given in the paper will contribute to the efficient operation of natural monopolies. Consequently, their activity will be oriented not on the reduction but on the increase of increments of the consumers or producers. Overall, the optimal management of the given fields will allow for improving the well-being throughout the country. In the article, conclusions are made, and the recommendations are developed to deliver effective policies and regulations toward the natural monopolies in Georgia.

Keywords: monopolies, natural monopolies, regulation, antimonopoly service

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Authors: O. B. Iskender, K. V. Ling, V. Dubanchet, L. Simonini

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This paper discusses the recent advances and future prospects of spacecraft position and attitude control using Model Predictive Control (MPC). First, the challenges of the space missions are summarized, in particular, taking into account the errors, uncertainties, and constraints imposed by the mission, spacecraft and, onboard processing capabilities. The summary of space mission errors and uncertainties provided in categories; initial condition errors, unmodeled disturbances, sensor, and actuator errors. These previous constraints are classified into two categories: physical and geometric constraints. Last, real-time implementation capability is discussed regarding the required computation time and the impact of sensor and actuator errors based on the Hardware-In-The-Loop (HIL) experiments. The rationales behind the scenarios’ are also presented in the scope of space applications as formation flying, attitude control, rendezvous and docking, rover steering, and precision landing. The objectives of these missions are explained, and the generic constrained MPC problem formulations are summarized. Three key design elements used in MPC design: the prediction model, the constraints formulation and the objective cost function are discussed. The prediction models can be linear time invariant or time varying depending on the geometry of the orbit, whether it is circular or elliptic. The constraints can be given as linear inequalities for input or output constraints, which can be written in the same form. Moreover, the recent convexification techniques for the non-convex geometrical constraints (i.e., plume impingement, Field-of-View (FOV)) are presented in detail. Next, different objectives are provided in a mathematical framework and explained accordingly. Thirdly, because MPC implementation relies on finding in real-time the solution to constrained optimization problems, computational aspects are also examined. In particular, high-speed implementation capabilities and HIL challenges are presented towards representative space avionics. This covers an analysis of future space processors as well as the requirements of sensors and actuators on the HIL experiments outputs. The HIL tests are investigated for kinematic and dynamic tests where robotic arms and floating robots are used respectively. Eventually, the proposed algorithms and experimental setups are introduced and compared with the authors' previous work and future plans. The paper concludes with a conjecture that MPC paradigm is a promising framework at the crossroads of space applications while could be further advanced based on the challenges mentioned throughout the paper and the unaddressed gap.

Keywords: convex optimization, model predictive control, rendezvous and docking, spacecraft autonomy

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Authors: Ozge Gurcanli

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Recent studies in active-learning focus on how student experience varies based on the content (e.g. STEM versus Humanities) and the medium (e.g. in-class exercises versus off-campus activities) of experiential learning. However, little is known whether the variation in classroom time and space within the same active learning context affects student experience. This study manipulated the use of classroom time for the active learning component of a developmental psychology course that is offered at a four-year university in the South-West Region of United States. The course uses a blended model: traditional and active learning. In the traditional learning component of the course, students do weekly readings, listen to lectures, and take midterms. In the active learning component, students make a documentary on a developmental topic as a final project. Students used the classroom time and space for the documentary in two ways: regular classroom time slots that were dedicated to the making of the documentary outside without the supervision of the professor (Classroom-time Outside) and lectures that offered basic instructions about how to make a documentary (Documentary Lectures). The study used the public teaching evaluations that are administered by the Office of Registrar’s. A total of two hundred and seven student evaluations were available across six semesters. Because the Office of Registrar’s presented the data separately without personal identifiers, One-Way ANOVA with four groups (Traditional, Experiential-Heavy: 19% Classroom-time Outside, 12% for Documentary Lectures, Experiential-Moderate: 5-7% for Classroom-time Outside, 16-19% for Documentary Lectures, Experiential Light: 4-7% for Classroom-time Outside, 7% for Documentary Lectures) was conducted on five key features (Organization, Quality, Assignments Contribution, Intellectual Curiosity, Teaching Effectiveness). Each measure used a five-point reverse-coded scale (1-Outstanding, 5-Poor). For all experiential conditions, the documentary counted towards 30% of the final grade. Organization (‘The instructors preparation for class was’), Quality (’Overall, I would rate the quality of this course as’) and Assignment Contribution (’The contribution of the graded work that made to the learning experience was’) did not yield any significant differences across four course types (F (3, 202)=1.72, p > .05, F(3, 200)=.32, p > .05, F(3, 203)=.43, p > .05, respectively). Intellectual Curiosity (’The instructor’s ability to stimulate intellectual curiosity was’) yielded a marginal effect (F (3, 201)=2.61, p = .053). Tukey’s HSD (p < .05) indicated that the Experiential-Heavy (M = 1.94, SD = .82) condition was significantly different than all other three conditions (M =1.57, 1.51, 1.58; SD = .68, .66, .77, respectively) showing that heavily active class-time did not elicit intellectual curiosity as much as others. Finally, Teaching Effectiveness (’Overall, I feel that the instructor’s effectiveness as a teacher was’) was significant (F (3, 198)=3.32, p <.05). Tukey’s HSD (p <.05) showed that students found the courses with moderate (M=1.49, SD=.62) to light (M=1.52, SD=.70) active class-time more effective than heavily active class-time (M=1.93, SD=.69). Overall, the findings of this study suggest that within the same active learning context, the time and the space dedicated to active learning results in different outcomes in intellectual curiosity and teaching effectiveness.

Keywords: active learning, learning outcomes, student experience, learning context

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Authors: S.I.Mukhin, S. Seidov, A. Mukherjee

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The Dicke model is a key tool for the description of correlated states of quantum atomic systems, excited by resonant photon absorption and subsequently emitting spontaneous coherent radiation in the superradiant state. The Dicke Hamiltonian (DH) is successfully used for the description of the dynamics of the Josephson Junction (JJ) array in a resonant cavity under applied current. In this work, we have investigated a generalized model, which is described by DH with a frustrating interaction term. This frustrating interaction term is explicitly the infinite coordinated interaction between all the spin half in the system. In this work, we consider an array of N superconducting islands, each divided into two sub-islands by a Josephson Junction, taken in a charged qubit / Cooper Pair Box (CPB) condition. The array is placed inside the resonant cavity. One important aspect of the problem lies in the dynamical nature of the physical observables involved in the system, such as condensed electric field and dipole moment. It is important to understand how these quantities behave with time to define the quantum phase of the system. The Dicke model without frustrating term is solved to find the dynamical solutions of the physical observables in analytic form. We have used Heisenberg’s dynamical equations for the operators and on applying newly developed Rotating Holstein Primakoff (HP) transformation and DH we have arrived at the four coupled nonlinear dynamical differential equations for the momentum and spin component operators. It is possible to solve the system analytically using two-time scales. The analytical solutions are expressed in terms of Jacobi's elliptic functions for the metastable ‘bound luminosity’ dynamic state with the periodic coherent beating of the dipoles that connect the two double degenerate dipolar ordered phases discovered previously. In this work, we have proceeded the analysis with the extended DH with a frustrating interaction term. Inclusion of the frustrating term involves complexity in the system of differential equations and it gets difficult to solve analytically. We have solved semi-classical dynamic equations using the perturbation technique for small values of Josephson energy EJ. Because the Hamiltonian contains parity symmetry, thus phase transition can be found if this symmetry is broken. Introducing spontaneous symmetry breaking term in the DH, we have derived the solutions which show the occurrence of finite condensate, showing quantum phase transition. Our obtained result matches with the existing results in this scientific field.

Keywords: Dicke Model, nonlinear dynamics, perturbation theory, superconductivity

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Authors: Adekeye Joshua Temitope

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“Transgender” presents a complexion of ambiguity in the African context and it remains a contested topography in the discourse of sexual identity. The casts and stigmatisations towards transgender unveils vital facts and intricacies often ignored in the academic communities; the problems and oppressions of given sex/gender system, the constrain of monogamy and ignorance of fluidity of human sexuality thereby generating dual discords of “enforced heterosexual” and “unavoidable homosexual.” The African culture voids transgender movements and perceive same-sex sexual behavior as “taboo or bad habits” and this provide reasonable explanations for the failure of asserting for the sexual rights in GLBT movement in most discourse on sexuality in the African context. However, we could not deny the real existence of active flowing and fluidity of human sexuality even though its variants could be latent. The incessant consciousness of the existence of transgender practices in Africa either in form of bisexual desire or bisexual behavior with or without sexual identity, including people who identify themselves as bisexual opens up the vision for us to reconsider and reexamine what constitutes such ambiguity and controversy of transgender identity at present time. The notion of identity politics in gay, lesbian, and transgender community has its complexity and debates in its historical development. This paper analyses the representation of the historical trajectory of transgender practices by presenting the dynamic transition of how people cognize transgender practices under different historical conditions since the understanding of historical transition of bisexual practices would be very crucial and meaningful for gender/sexuality liberation movement at present time and in the future. The paper did a juxtaposition of the trajectories of bisexual practices between Anglo-American world and Africa, as it has certain similarities and differences within diverse historical complexities. The similar condition is the emergence of gay identity under the influence of capitalism but within different cultural context. Therefore, the political economy of each cultural context plays very important role in understanding the formation of sexual identities historically and its development and influence for the GLBT movement afterwards and in the future. By reexamining Kinsey’s categorization and applying Klein’s argument on individual’s sexual orientation this paper is poised to break the given and fixed connection among sexual behavior/sexual orientation/sexual identity, on the other hand to present the potential fluidity of human sexuality by reconsidering and reexamining the present given sex/gender system in our world. The paper concludes that it is obligatory for the essentialist and exclusionary trend at this historical moment since gay and lesbian communities in Africa need to clearly demonstrate and voice for themselves under the nuances of gender/sexuality liberation.

Keywords: heterosexual, homosexual, identity politics, queer politics, transgender

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Authors: Smita Mondal, Dinesh Kumar Pandey, Prakash Biswas

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During past two decades, considerable attention has been given to the value addition of biodiesel derived glycerol (~10wt.%) to make the biodiesel industry economically viable. Among the various glycerol value-addition methods, hydrogenolysis of glycerol to 1,2-propanediol is one of the attractive and promising routes. In this study, highly active and selective γ-Al₂O₃ supported bimetallic Cu-Ni catalyst was developed for selective hydrogenolysis of glycerol to 1,2-propanediol in the liquid phase. The catalytic performance was evaluated in a high-pressure autoclave reactor. The formation of mixed oxide indicated the strong interaction of Cu, Ni with the alumina support. Experimental results demonstrated that bimetallic copper-nickel catalyst was more active and selective to 1,2-PDO as compared to monometallic catalysts due to bifunctional behavior. To verify the effect of calcination temperature on the formation of Cu-Ni mixed oxide phase, the calcination temperature of 20wt.% Cu:Ni(1:1)/Al₂O₃ catalyst was varied from 300°C-550°C. The physicochemical properties of the catalysts were characterized by various techniques such as specific surface area (BET), X-ray diffraction study (XRD), temperature programmed reduction (TPR), and temperature programmed desorption (TPD). The BET surface area and pore volume of the catalysts were in the range of 71-78 m²g⁻¹, and 0.12-0.15 cm³g⁻¹, respectively. The peaks at the 2θ range of 43.3°-45.5° and 50.4°-52°, was corresponded to the copper-nickel mixed oxidephase [JCPDS: 78-1602]. The formation of mixed oxide indicated the strong interaction of Cu, Ni with the alumina support. The crystallite size decreased with increasing the calcination temperature up to 450°C. Further, the crystallite size was increased due to agglomeration. Smaller crystallite size of 16.5 nm was obtained for the catalyst calcined at 400°C. Total acidic sites of the catalysts were determined by NH₃-TPD, and the maximum total acidic of 0.609 mmol NH₃ gcat⁻¹ was obtained over the catalyst calcined at 400°C. TPR data suggested the maximum of 75% degree of reduction of catalyst calcined at 400°C among all others. Further, 20wt.%Cu:Ni(1:1)/γ-Al₂O₃ catalyst calcined at 400°C exhibited highest catalytic activity ( > 70%) and 1,2-PDO selectivity ( > 85%) at mild reaction condition due to highest acidity, highest degree of reduction, smallest crystallite size. Further, the modified Power law kinetic model was developed to understand the true kinetic behaviour of hydrogenolysis of glycerol over 20wt.%Cu:Ni(1:1)/γ-Al₂O₃ catalyst. Rate equations obtained from the model was solved by ode23 using MATLAB coupled with Genetic Algorithm. Results demonstrated that the model predicted data were very well fitted with the experimental data. The activation energy of the formation of 1,2-PDO was found to be 45 kJ mol⁻¹.

Keywords: glycerol, 1, 2-PDO, calcination, kinetic

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Authors: Felipe M. de Freitas, Icaro V. Soares, Lucas L. L. Fortes, Sandro T. M. Gonçalves, Úrsula D. C. Resende

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The SPICE-based simulators are quite robust and widely used for simulation of electronic circuits, their algorithms support linear and non-linear lumped components and they can manipulate an expressive amount of encapsulated elements. Despite the great potential of these simulators based on SPICE in the analysis of quasi-static electromagnetic field interaction, that is, at low frequency, these simulators are limited when applied to microwave hybrid circuits in which there are both lumped and distributed elements. Usually the spatial discretization of the FDTD (Finite-Difference Time-Domain) method is done according to the actual size of the element under analysis. After spatial discretization, the Courant Stability Criterion calculates the maximum temporal discretization accepted for such spatial discretization and for the propagation velocity of the wave. This criterion guarantees the stability conditions for the leapfrogging of the Yee algorithm; however, it is known that for the field update, the stability of the complete FDTD procedure depends on factors other than just the stability of the Yee algorithm, because the FDTD program needs other algorithms in order to be useful in engineering problems. Examples of these algorithms are Absorbent Boundary Conditions (ABCs), excitation sources, subcellular techniques, grouped elements, and non-uniform or non-orthogonal meshes. In this work, the influence of the stability of the FDTD method in the modeling of concentrated elements such as resistive sources, resistors, capacitors, inductors and diode will be evaluated. In this paper is proposed, therefore, the electromagnetic modeling of electronic components in order to create models that satisfy the needs for simulations of circuits in ultra-wide frequencies. The models of the resistive source, the resistor, the capacitor, the inductor, and the diode will be evaluated, among the mathematical models for lumped components in the LE-FDTD method (Lumped-Element Finite-Difference Time-Domain), through the parametric analysis of Yee cells size which discretizes the lumped components. In this way, it is sought to find an ideal cell size so that the analysis in FDTD environment is in greater agreement with the expected circuit behavior, maintaining the stability conditions of this method. Based on the mathematical models and the theoretical basis of the required extensions of the FDTD method, the computational implementation of the models in Matlab® environment is carried out. The boundary condition Mur is used as the absorbing boundary of the FDTD method. The validation of the model is done through the comparison between the obtained results by the FDTD method through the electric field values and the currents in the components, and the analytical results using circuit parameters.

Keywords: hybrid circuits, LE-FDTD, lumped element, parametric analysis

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Authors: Majid Farsadrouh Rashti, Amir Shafiee Kisomi, Parisa Jahani

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The direct ethanol fuel cells (DEFCs) are contemplated as a promising energy source because, In addition to being used in portable electronic devices, it is also used for electric vehicles. The synthesis of bimetallic nanostructures due to their novel optical, catalytic and electronic characteristic which is precisely in contrast to their monometallic counterparts is attracting extensive attention. Galvanic replacement (sometimes is named to as cementation or immersion plating) is an uncomplicated and effective technique for making nanostructures (such as core-shell) of different metals, semiconductors, and their application in DEFCs. The replacement of galvanic does not need any external power supply compared to electrodeposition. In addition, it is different from electroless deposition because there is no need for a reducing agent to replace galvanizing. In this paper, a fast method for the palladium (Pd) wire nanostructures synthesis with the great surface area through galvanic replacement reaction utilizing copper nanowires (CuNWS) as a template by the assistance of ultrasound under room temperature condition is proposed. To evaluate the morphology and composition of Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan, emission scanning electron microscopy, energy dispersive X-ray spectroscopy were applied. In order to measure the phase structure of the electrocatalysts were performed via room temperature X-ray powder diffraction (XRD) applying an X-ray diffractometer. Various electrochemical techniques including chronoamperometry and cyclic voltammetry were utilized for the electrocatalytic activity of ethanol electrooxidation and durability in basic solution. Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan catalyst demonstrated substantially enhanced performance and long-term stability for ethanol electrooxidation in the basic solution in comparison to commercial Pd/C that demonstrated the potential in utilizing Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan as efficient catalysts towards ethanol oxidation. Noticeably, the Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan presented excellent catalytic activities with a peak current density of 320.73 mAcm² which was 9.5 times more than in comparison to Pd/C (34.2133 mAcm²). Additionally, activation energy thermodynamic and kinetic evaluations revealed that the Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan catalyst has lower compared to Pd/C which leads to a lower energy barrier and an excellent charge transfer rate towards ethanol oxidation.

Keywords: core-shell structure, electrocatalyst, ethanol oxidation, galvanic replacement reaction

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Authors: Saurabh Sharma, Yong Sun, Bruce Vernham

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Accurate prediction of NOx emission is a continuous challenge in the field of diesel engine-out emission modeling. Performing experiments for each conditions and scenario cost significant amount of money and man hours, therefore model-based development strategy has been implemented in order to solve that issue. NOx formation is highly dependent on the burn gas temperature and the O₂ concentration inside the cylinder. The current empirical models are developed by calibrating the parameters representing the engine operating conditions with respect to the measured NOx. This makes the prediction of purely empirical models limited to the region where it has been calibrated. An alternative solution to that is presented in this paper, which focus on the utilization of in-cylinder combustion parameters to form a predictive semi-empirical NOx model. The result of this work is shown by developing a fast and predictive NOx model by using the physical parameters and empirical correlation. The model is developed based on the steady state data collected at entire operating region of the engine and the predictive combustion model, which is developed in Gamma Technology (GT)-Power by using Direct Injected (DI)-Pulse combustion object. In this approach, temperature in both burned and unburnt zone is considered during the combustion period i.e. from Intake Valve Closing (IVC) to Exhaust Valve Opening (EVO). Also, the oxygen concentration consumed in burnt zone and trapped fuel mass is also considered while developing the reported model.  Several statistical methods are used to construct the model, including individual machine learning methods and ensemble machine learning methods. A detailed validation of the model on multiple diesel engines is reported in this work. Substantial numbers of cases are tested for different engine configurations over a large span of speed and load points. Different sweeps of operating conditions such as Exhaust Gas Recirculation (EGR), injection timing and Variable Valve Timing (VVT) are also considered for the validation. Model shows a very good predictability and robustness at both sea level and altitude condition with different ambient conditions. The various advantages such as high accuracy and robustness at different operating conditions, low computational time and lower number of data points requires for the calibration establishes the platform where the model-based approach can be used for the engine calibration and development process. Moreover, the focus of this work is towards establishing a framework for the future model development for other various targets such as soot, Combustion Noise Level (CNL), NO₂/NOx ratio etc.

Keywords: diesel engine, machine learning, NOₓ emission, semi-empirical

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Authors: N. Demertzis, J. L. Bowen

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Sepsis is a complex and rapidly evolving condition, resulting from uncontrolled prolonged activation of host immune system due to pathogenic insult. The aim of this study is the development of a multiplex electrochemical sensing platform, capable of detecting both pathogen associated and host immune markers to enable the rapid and definitive diagnosis of sepsis. A combination of aptamers and molecular imprinting approaches have been employed to generate sensing systems for lipopolysaccharide (LPS), c-reactive protein (CRP) and procalcitonin (PCT). Gold working electrodes were mechanically polished and electrochemically cleaned with 0.1 M sulphuric acid using cyclic voltammetry (CV). Following activation, a self-assembled monolayer (SAM) was generated, by incubating the electrodes with a thiolated anti-LPS aptamer / dithiodibutiric acid (DTBA) mixture (1:20). 3-aminophenylboronic acid (3-APBA) in combination with the anti-LPS aptamer was used for the development of the hybrid molecularly imprinted sensor (apta-MIP). Aptasensors, targeting PCT and CRP were also fabricated, following the same approach as in the case of LPS, with mercaptohexanol (MCH) replacing DTBA. In the case of the CRP aptasensor, the SAM was formed following incubation of a 1:1 aptamer: MCH mixture. However, in the case of PCT, the SAM was formed with the aptamer itself, with subsequent backfilling with 1 μM MCH. The binding performance of all systems has been evaluated using electrochemical impedance spectroscopy. The apta-MIP’s polymer thickness is controlled by varying the number of electropolymerisation cycles. In the ideal number of polymerisation cycles, the polymer must cover the electrode surface and create a binding pocket around LPS and its aptamer binding site. Less polymerisation cycles will create a hybrid system which resembles an aptasensor, while more cycles will be able to cover the complex and demonstrate a bulk polymer-like behaviour. Both aptasensor and apta-MIP were challenged with LPS and compared to conventional imprinted (absence of aptamer from the binding site, polymer formed in presence of LPS) and non-imprinted polymers (NIPS, absence of LPS whilst hybrid polymer is formed). A stable LPS aptasensor, capable of detecting down to 5 pg/ml of LPS was generated. The apparent Kd of the system was estimated at 17 pM, with a Bmax of approximately 50 pM. The aptasensor demonstrated high specificity to LPS. The apta-MIP demonstrated superior recognition properties with a limit of detection of 1 fg/ml and a Bmax of 100 pg/ml. The CRP and PCT aptasensors were both able to detect down to 5 pg/ml. Whilst full binding performance is currently being evaluated, there is none of the sensors demonstrate cross-reactivity towards LPS, CRP or PCT. In conclusion, stable aptasensors capable of detecting LPS, PCT and CRP at low concentrations have been generated. The realisation of a multiplex panel such as described herein, will effectively contribute to the rapid, personalised diagnosis of sepsis.

Keywords: aptamer, electrochemical impedance spectroscopy, molecularly imprinted polymers, sepsis

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Authors: Birge Yildirim Okta

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This paper aims to narrate the story of Atatürk Cultural Center in Taksim Square, which was demolished in 2018 and discuss its architectonic as a social place of memory and its existence and demolishment as the space of politics. The paper uses narrative discourse analysis to research Atatürk Cultural Center (AKM) as a place of memory and space of politics from the establishment of the Turkish Republic (1923) until today. After the establishment of the Turkish Republic, one of the most important implementations in Taksim Square, reflecting the internationalist style, was the construction of the Opera Building in Prost Plan. The first design of the opera building belonged to Aguste Perret, which could not be implemented due to economic hardship during World War II. Later the project was designed by architects Feridun Kip and Rüknettin Güney in 1946 but could not be completed due to the 1960 military coup. Later the project was shifted to another architect Hayati Tabanlıoglu, with a change in its function as a cultural center. Eventually, the construction of the building was completed in 1969 in a completely different design. AKM became a symbol of republican modernism not only with its modern architectural style but also with it is function as the first opera building of the Republic, reflecting the western, modern cultural heritage by professional groups, artists, and the intelligentsia. In 2005, Istanbul’s council for the protection of cultural heritage decided to list AKM as a grade 1 cultural heritage, ending a period of controversy which saw calls for the demolition of the center as it was claimed, it ended its useful lifespan. In 2008 the building was announced to be closed for repairs and restoration. Over the following years, the building was demolished piece by piece silently while the Taksim mosque has been built just in front of Atatürk Cultural Center. Belonging to the early republican period AKM was a representation of the cultural production of modern society for the emergence and westward looking, secular public space in Turkey. Its erasure from the Taksim scene under the rule of the conservative government, Justice, and Development Party, and the construction of the Taksim mosque in front of AKM’s parcel is also representational. The question of governing the city through space has always been an important aspect for governments, those holding political power since cities are the chaotic environments that are seen as a threat for the governments, carrying the tensions of the proletariat or the contradictory groups. The story of AKM as a dispositive or a regulatory apparatus demonstrates how space itself is becoming a political medium, to transform the socio-political condition. The paper narrates the existence and demolishment of the Atatürk Cultural Center by discussing the constructed and demolished building as a place of memory and space of politics.

Keywords: space of politics, place of memory, Atatürk Cultural Center, Taksim square, collective memory

Procedia PDF Downloads 140

Authors: Arpit Sachan, Nilanshu Kumar

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This paper tries to understand the nuances of feminisation of agriculture in the Indian context and how that is associated with better intrahousehold bargaining power for women. The economic survey of India indicates a constant increase in the share of the female workforce in Indian agriculture in the past few decades. This can be accounted for by many factors like the migration of male workers to urban areas and, therefore, the complete burden of agriculture shifting on the female counterparts. Therefore this study is an attempt to study that how this increase in the female workforce corresponds to a better decision-making ability for women in rural farm households. This paper is an attempt to carefully evaluate this aspect of the feminisation of Indian agriculture. The paper tries to study how various factors that improve the status of women in agriculture change with things like resource ownership. This paper uses both the macro-level and micro-level data to study the dynamics of the proportion of the workforce in agriculture across different states in India and how that has translated into better indicators for women in rural areas. The fall in India’s rank in the global gender wage gap index is alarming in such a context, and this creates a puzzle with increasing female workforce participation. The paper will consider if the condition of women improved over time with the increased share of employment or not? Using field survey data, this paper tries to understand if there exists any digression for some of the indicators both at the macro and micro level. The paper also tries to integrate the economic understanding of gender aspects of the workforce and the sociological stance prevailing in the existing literature. Therefore, this paper takes a mixed-method approach to better understand the role that social structure plays in the improved status of women within and across various households. Therefore, this paper will finally help us understanding if at all there is a feminisation of Indian agriculture or it's just exploitation of a different kind. This study intends to create a distinction between the gendered labour force in Indian agriculture and the complete democratization of Indian agriculture. The study is primarily focused on areas where the exodus of male migrants pushes women to work on agricultural farms. The question posits is whether it is the willingness of women to work in agriculture or is it urbanisation and development-induced conditions that make women work in agriculture as farm labourers? The motive is to understand if factors like resource ownership and the ability to autonomous decision-making are interlinked with an increased proportion of the female workforce or not? Based on this framework, we finally provide a brief comment on policy implications of government intervention in improving Indian agriculture and the gender aspects associated with it.

Keywords: feminisation, intrahousehold bargaining, farm households, migration, agriculture, decision-making

Procedia PDF Downloads 130

Authors: Richard J. Hanowski, Rebecca L. Hammond

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Very few studies have been conducted to investigate safety issues associated with motorcoach/bus operations. The current study investigates the impact that roadway infrastructure, including locality, roadway grade, traffic flow and traffic density, have on bus safety. A naturalistic driving study was conducted in the U.S.A that involved 43 motorcoaches. Two fleets participated in the study and over 600,000 miles of naturalistic driving data were collected. Sixty-five bus drivers participated in this study; 48 male and 17 female. The average age of the drivers was 49 years. A sophisticated data acquisition system (DAS) was installed on each of the 43 motorcoaches and a variety of kinematic and video data were continuously recorded. The data were analyzed by identifying safety critical events (SCEs), which included crashes, near-crashes, crash-relevant conflicts, and unintentional lane deviations. Additionally, baseline (normative driving) segments were also identified and analyzed for comparison to the SCEs. This presentation highlights the need for bus safety research and the methods used in this data collection effort. With respect to elements of roadway infrastructure, this study highlights the methods used to assess locality, roadway grade, traffic flow, and traffic density. Locality was determined by manual review of the recorded video for each event and baseline and was characterized in terms of open country, residential, business/industrial, church, playground, school, urban, airport, interstate, and other. Roadway grade was similarly determined through video review and characterized in terms of level, grade up, grade down, hillcrest, and dip. The video was also used to make a determination of the traffic flow and traffic density at the time of the event or baseline segment. For traffic flow, video was used to assess which of the following best characterized the event or baseline: not divided (2-way traffic), not divided (center 2-way left turn lane), divided (median or barrier), one-way traffic, or no lanes. In terms of traffic density, level-of-service categories were used: A1, A2, B, C, D, E, and F. Highlighted in this abstract are only a few of the many roadway elements that were coded in this study. Other elements included lighting levels, weather conditions, roadway surface conditions, relation to junction, and roadway alignment. Note that a key component of this study was to assess the impact that driver distraction and fatigue have on bus operations. In this regard, once the roadway elements had been coded, the primary research questions that were addressed were (i) “What environmental condition are associated with driver choice of engagement in tasks?”, and (ii) “what are the odds of being in a SCE while engaging in tasks while encountering these conditions?”. The study may be of interest to researchers and traffic engineers that are interested in the relationship between roadway infrastructure elements and safety events in motorcoach bus operations.

Keywords: bus safety, motorcoach, naturalistic driving, roadway infrastructure

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Authors: F. Pal-Fam, S. Keszthelyi

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Phytosanitary condition of sunflower (Helianthus annuus L.) was endangered by several phytopathogenic agents, mainly microfungi, such as Sclerotinia sclerotiorum, Diaporthe helianthi, Plasmopara halstedtii, Macrophomina phaseolina and so on. There are more agrotechnical and chemical technologies against them, for instance, tolerant hybrids, crop rotations and eventually several in-crop chemical treatments. There are different fungicide treatment methods in sunflower in Hungarian agricultural practice in the quest of obtaining healthy and economic plant products. Besides, there are many choices of useable active ingredients in Hungarian sunflower protection. This study carried out into the examination of the effect of five different fungicide active substances (found on the market) and three different application modes (early; late; and early and late treatments) in a total number of 9 sample plots, 0.1 ha each other. Five successive vegetation periods have been investigated in long term, between 2013 and 2017. The treatments were: 1)untreated control; 2) boscalid and dimoxystrobin late treatment (July); 3) boscalid and dimoxystrobin early treatment (June); 4) picoxystrobin and cyproconazole early treatment; 5) picoxystrobin and cymoxanil and famoxadone early treatment; 6) picoxystrobin and cyproconazole early; cymoxanil and famoxadone late treatments; 7) picoxystrobin and cyproconazole early; picoxystrobin and cymoxanil and famoxadone late treatments; 8) trifloxystrobin and cyproconazole early treatment; and 9) trifloxystrobin and cyproconazole both early and late treatments. Due to the very different yearly weather conditions different phytopathogenic fungi were dominant in the particular years: Diaporthe and Alternaria in 2013; Alternaria and Sclerotinia in 2014 and 2015; Alternaria, Sclerotinia and Diaporthe in 2016; and Alternaria in 2017. As a result of treatments ‘infection frequency’ and ‘infestation rate’ showed a significant decrease compared to the control plot. There were no significant differences between the efficacies of the different fungicide mixes; all were almost the same effective against the phytopathogenic fungi. The most dangerous Sclerotinia infection was practically eliminated in all of the treatments. Among the single treatments, the late treatment realised in July was the less efficient, followed by the early treatments effectuated in June. The most efficient was the double treatments realised in both June and July, resulting 70-80% decrease of the infection frequency, respectively 75-90% decrease of the infestation rate, comparing with the control plot in the particular years. The lowest yield quantity was observed in the control plot, followed by the late single treatment. The yield of the early single treatments was higher, while the double treatments showed the highest yield quantities (18.3-22.5% higher than the control plot in particular years). In total, according to our five years investigation, the most effective application mode is the double in-crop treatment per vegetation time, which is reflected by the yield surplus.

Keywords: fungicides, treatments, phytopathogens, sunflower

Procedia PDF Downloads 141

Authors: Soo-Yong Cho, Chong-Hyun Cho, Chae-Whan Rim, Sang-Kyu Choi, Jin-Gyun Kim, Ju-Seok Nam

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Recently, vertical axis wind turbines (VAWT) have been widely used to produce electricity even in urban. They have several merits such as low sound noise, easy installation of the generator and simple structure without yaw-control mechanism and so on. However, their blades are operated under the influence of the trailing vortices generated by the preceding blades. This phenomenon deteriorates its output power and makes difficulty predicting correctly its performance. In order to improve the performance of VAWT, wind power towers can be applied. Usually, the wind power tower can be constructed as a multi-story building to increase the frontal area of the wind stream. Hence, multiple sets of the VAWT can be installed within the wind power tower, and they can be operated at high elevation. Many different types of wind power tower can be used in the field. In this study, a wind power tower with circular column shape was applied, and the VAWT was installed at the center of the wind power tower. Seven guide walls were used as a strut between the floors of the wind power tower. These guide walls were utilized not only to increase the wind velocity within the wind power tower but also to adjust the wind direction for making a better working condition on the VAWT. Hence, some important design variables, such as the distance between the wind turbine and the guide wall, the outer diameter of the wind power tower, the direction of the guide wall against the wind direction, should be considered to enhance the output power on the VAWT. A numerical analysis was conducted to find the optimum dimension on design variables by using the computational fluid dynamics (CFD) among many prediction methods. The CFD could be an accurate prediction method compared with the stream-tube methods. In order to obtain the accurate results in the CFD, it needs the transient analysis and the full three-dimensional (3-D) computation. However, this full 3-D CFD could be hard to be a practical tool because it requires huge computation time. Therefore, the reduced computational domain is applied as a practical method. In this study, the computations were conducted in the reduced computational domain and they were compared with the experimental results in the literature. It was examined the mechanism of the difference between the experimental results and the computational results. The computed results showed this computational method could be an effective method in the design methodology using the optimization algorithm. After validation of the numerical method, the CFD on the wind power tower was conducted with the important design variables affecting the performance of VAWT. The results showed that the output power of the VAWT obtained using the wind power tower was increased compared to them obtained without the wind power tower. In addition, they showed that the increased output power on the wind turbine depended greatly on the dimension of the guide wall.

Keywords: CFD, performance, VAWT, wind power tower

Procedia PDF Downloads 387

Authors: Jayme R. T. Silva, Paulo G. P. Toro, Angelo Passaro, Giannino P. Camillo, Antonio C. Oliveira

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An in-house C++ code has been developed, at the Prof. Henry T. Nagamatsu Laboratory of Aerothermodynamics and Hypersonics from the Institute of Advanced Studies (Brazil), to estimate the aerothermodynamic properties around the Hypersonic Vehicle Integrated to the Scramjet. In the future, this code will be applied to the design of the Brazilian Scramjet Technological Demonstrator 14-X B. The first step towards accomplishing this objective, is to apply the in-house C++ code at the leading edge of a flat plate, simulating the leading edge of the 14-X Hypersonic Vehicle, making possible the wave phenomena of oblique shock and boundary layer to be analyzed. The development of modern hypersonic space vehicles requires knowledge regarding the characteristics of hypersonic flows in the vicinity of a leading edge of lifting surfaces. The strong interaction between a shock wave and a boundary layer, in a high supersonic Mach number 4 viscous flow, close to the leading edge of the plate, considering no slip condition, is numerically investigated. The small slip region is neglecting. The study consists of solving the fluid flow equations for unstructured meshes applying the SIMPLE algorithm for Finite Volume Method. Unstructured meshes are generated by the in-house software ‘Modeler’ that was developed at Virtual’s Engineering Laboratory from the Institute of Advanced Studies, initially developed for Finite Element problems and, in this work, adapted to the resolution of the Navier-Stokes equations based on the SIMPLE pressure-correction scheme for all-speed flows, Finite Volume Method based. The in-house C++ code is based on the two-dimensional Navier-Stokes equations considering non-steady flow, with nobody forces, no volumetric heating, and no mass diffusion. Air is considered as calorically perfect gas, with constant Prandtl number and Sutherland's law for the viscosity. Solutions of the flat plate problem for Mach number 4 include pressure, temperature, density and velocity profiles as well as 2-D contours. Also, the boundary layer thickness, boundary conditions, and mesh configurations are presented. The same problem has been solved by the academic license of the software Ansys Fluent and for another C++ in-house code, which solves the fluid flow equations in structured meshes, applying the MacCormack method for Finite Difference Method, and the results will be compared.

Keywords: boundary-layer, scramjet, simple algorithm, shock wave

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Authors: Gómez S. Jennifer, Méndez V. Camila, Moncayo M. Diana, Vega M. Lizeth

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The cape gooseberry is a climacteric fruit; Colombia is one of the principal exporters in the world. The environmental condition of temperature and relative moisture decreases the titratable acidity and pH. These conditions and fruit maturation result in the fungal proliferation of Botrytis cinerea disease. Plastic packaging for fresh cape gooseberries was used for mechanical damage protection but created a suitable atmosphere for fungal growth. Beta-cyclodextrins are currently implemented as coatings for the encapsulation of hydrophobic compounds, for example, with bioactive compounds from essential oils such as cinnamaldehyde, which has a high antimicrobial capacity. However, it is a volatile substance. In this article, the casting method was used to obtain a polylactic acid (PLA) polymer film containing the beta-cyclodextrin-cinnamaldehyde inclusion complex, generating an insert that allowed the controlled release of the antifungal substance in packed cape gooseberries to decrease contamination by Botrytis cinerea in a latent state during storage. For the encapsulation technique, three ratios for the cinnamaldehyde: beta-cyclodextrin inclusion complex were proposed: (25:75), (40:60), and (50:50). Spectrophotometry, colorimetry in L*a*b* coordinate space and scanning electron microscopy (SEM) were made for the complex characterization. Subsequently, two ratios of tween and water (40:60) and (50:50) were used to obtain the polylactic acid (PLA) film. To determine mechanical and physical parameters of colourimetry in L*a*b* coordinate space, atomic force microscopy and stereoscopy were done to determine the transparency and flexibility of the film; for both cases, Statgraphics software was used to determine the best ratio in each of the proposed phases, where for encapsulation it was (50:50) with an encapsulation efficiency of 65,92%, and for casting the ratio (40:60) obtained greater transparency and flexibility that permitted its incorporation into the polymeric packaging. A liberation assay was also developed under ambient temperature conditions to evaluate the concentration of cinnamaldehyde inside the packaging through gas chromatography for three weeks. It was found that the insert had a controlled release. Nevertheless, a higher cinnamaldehyde concentration is needed to obtain the minimum inhibitory concentration for the fungus Botrytis cinerea (0.2g/L). The homogeneity of the cinnamaldehyde gas phase inside the packaging can be improved by considering other insert configurations. This development aims to impact emerging food preservation technologies with the controlled release of antifungals to reduce the affectation of the physico-chemical and sensory properties of the fruit as a result of contamination by microorganisms in the postharvest stage.

Keywords: antifungal, casting, encapsulation, postharvest

Procedia PDF Downloads 75

Authors: Junze Li, M. Li

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Laser diodes fabricated from the III-nitride material system are emerging solutions for the next generation telecommunication systems and optical clocks based on Ca at 397nm, Rb at 420.2nm and Yb at 398.9nm combined 556 nm. Most of the applications require single longitudinal optical mode lasers, with very narrow linewidth and compact size, such as communication systems and laser cooling. In this case, the GaN based distributed feedback (DFB) laser diode is one of the most effective candidates with gratings are known to operate with narrow spectra as well as high power and efficiency. Given the wavelength range, the period of the first-order diffraction grating is under 100 nm, and the realization of such gratings is technically difficult due to the narrow line width and the high quality nitride overgrowth based on the Bragg grating. Some groups have reported GaN DFB lasers with high order distributed feedback surface gratings, which avoids the overgrowth. However, generally the strength of coupling is lower than that with Bragg grating embedded into the waveguide within the GaN laser structure by two-step-epitaxy. Therefore, the overgrowth on the grating technology need to be studied and optimized. Here we propose to fabricate the fine step shape structure of first-order grating by the nanoimprint combined inductively coupled plasma (ICP) dry etching, then carry out overgrowth high quality AlGaN film by metalorganic chemical vapor deposition (MOCVD). Then a series of gratings with different period, depths and duty ratios are designed and fabricated to study the influence of grating structure to the nano-heteroepitaxy. Moreover, we observe the nucleation and growth process by step-by-step growth to study the growth mode for nitride overgrowth on grating, under the condition that the grating period is larger than the mental migration length on the surface. The AFM images demonstrate that a smooth surface of AlGaN film is achieved with an average roughness of 0.20 nm over 3 × 3 μm2. The full width at half maximums (FWHMs) of the (002) reflections in the XRD rocking curves are 278 arcsec for the AlGaN film, and the component of the Al within the film is 8% according to the XRD mapping measurement, which is in accordance with design values. By observing the samples with growth time changing from 200s, 400s to 600s, the growth model is summarized as the follow steps: initially, the nucleation is evenly distributed on the grating structure, as the migration length of Al atoms is low; then, AlGaN growth alone with the grating top surface; finally, the AlGaN film formed by lateral growth. This work contributed to carrying out GaN DFB laser by fabricating grating and overgrowth on the nano-grating patterned substrate by wafer scale, moreover, growth dynamics had been analyzed as well.

Keywords: DFB laser, MOCVD, nanoepitaxy, III-niitride

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Authors: Shofiayuningtyas Luftiani

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Some private schools in Indonesia started integrating the online program Gizmos in the teaching-learning process. Gizmos was developed to supplement the existing curriculum by integrating it into the instructional programs. The program has some features using an inquiry-based simulation, in which students conduct exploration by using a worksheet while teachers use the teacher guidelines to direct and assess students’ performance In this study, the discussion about Gizmos highlights its features as the assessment media of mathematics learning for secondary school students. The discussion is based on the case study and literature review from the Indonesian context. The purpose of applying Gizmos as an assessment media refers to the diagnostic assessment. As a part of the diagnostic assessment, the teachers review the student exploration sheet, analyze particularly in the students’ difficulties and consider findings in planning future learning process. This assessment becomes important since the teacher needs the data about students’ persistent weaknesses. Additionally, this program also helps to build student’ understanding by its interactive simulation. Currently, the assessment over-emphasizes the students’ answers in the worksheet based on the provided answer keys while students perform their skill in translating the question, doing the simulation and answering the question. Whereas, the assessment should involve the multiple perspectives and sources of students’ performance since teacher should adjust the instructional programs with the complexity of students’ learning needs and styles. Consequently, the approach to improving the assessment components is selected to challenge the current assessment. The purpose of this challenge is to involve not only the cognitive diagnosis but also the analysis of skills and error. Concerning the selected setting for this diagnostic assessment that develops the combination of cognitive diagnosis, skills analysis and error analysis, the teachers should create an assessment rubric. The rubric plays the important role as the guide to provide a set of criteria for the assessment. Without the precise rubric, the teacher potentially ineffectively documents and follows up the data about students at risk of failure. Furthermore, the teachers who employ the program of Gizmos as the diagnostic assessment might encounter some obstacles. Based on the condition of assessment in the selected setting, the obstacles involve the time constrain, the reluctance of higher teaching burden and the students’ behavior. Consequently, the teacher who chooses the Gizmos with those approaches has to plan, implement and evaluate the assessment. The main point of this assessment is not in the result of students’ worksheet. However, the diagnostic assessment has the two-stage process; the process to prompt and effectively follow-up both individual weaknesses and those of the learning process. Ultimately, the discussion of Gizmos as the media of the diagnostic assessment refers to the effort to improve the mathematical learning process.

Keywords: diagnostic assessment, error analysis, Gizmos online program, skills analysis

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Authors: Alan N. A. Heberle, Salatiel W. Da Silva, Valentin Perez-Herranz, Andrea M. Bernardes

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Contaminants of emerging concern are substances widely used, such as pharmaceutical products. These compounds represent risk for both wild and human life since they are not completely removed from wastewater by conventional wastewater treatment plants. In the environment, they can be harm even in low concentration (µ or ng/L), causing bacterial resistance, endocrine disruption, cancer, among other harmful effects. One of the most common taken medicine to treat cardiocirculatory diseases is the Atenolol (ATL), a β-Blocker, which is toxic to aquatic life. In this way, it is necessary to implement a methodology, which is capable to promote the degradation of the ATL, to avoid the environmental detriment. A very promising technology is the advanced electrochemical oxidation (AEO), which mechanisms are based on the electrogeneration of reactive radicals (mediated oxidation) and/or on the direct substance discharge by electron transfer from contaminant to electrode surface (direct oxidation). The hydroxyl (HO•) and sulfate (SO₄•⁻) radicals can be generated, depending on the reactional medium. Besides that, at some condition, the peroxydisulfate (S₂O₈²⁻) ion is also generated from the SO₄• reaction in pairs. Both radicals, ion, and the direct contaminant discharge can break down the molecule, resulting in the degradation and/or mineralization. However, ATL molecule and byproducts can still remain in the treated solution. On this wise, some efforts can be done to implement the AEO process, being one of them the use of a cationic membrane to separate the cathodic (reduction) from the anodic (oxidation) reactor compartment. The aim of this study is investigate the influence of the implementation of a cationic membrane (Nafion®-117) to separate both cathodic and anodic, AEO reactor compartments. The studied reactor was a filter-press, with bath recirculation mode, flow 60 L/h. The anode was an Nb/BDD2500 and the cathode a stainless steel, both bidimensional, geometric surface area 100 cm². The solution feeding the anodic compartment was prepared with ATL 100 mg/L using Na₂SO₄ 4 g/L as support electrolyte. In the cathodic compartment, it was used a solution containing Na₂SO₄ 71 g/L. Between both solutions was placed the membrane. The applied currents densities (iₐₚₚ) of 5, 20 and 40 mA/cm² were studied over 240 minutes treatment time. Besides that, the ATL decay was analyzed by ultraviolet spectroscopy (UV/Vis). The mineralization was determined performing total organic carbon (TOC) in TOC-L CPH Shimadzu. In the cases without membrane, the iₐₚₚ 5, 20 and 40 mA/cm² resulted in 55, 87 and 98 % ATL degradation at the end of treatment time, respectively. However, with membrane, the degradation, for the same iₐₚₚ, was 90, 100 and 100 %, spending 240, 120, 40 min for the maximum degradation, respectively. The mineralization, without membrane, for the same studied iₐₚₚ, was 40, 55 and 72 %, respectively at 240 min, but with membrane, all tested iₐₚₚ reached 80 % of mineralization, differing only in the time spent, 240, 150 and 120 min, for the maximum mineralization, respectively. The membrane increased the ATL oxidation, probably due to avoid oxidant ions (S₂O₈²⁻) reduction on the cathode surface.

Keywords: contaminants of emerging concern, advanced electrochemical oxidation, atenolol, cationic membrane, double compartment reactor

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Authors: Julio Aguirre, Yohnny Campana, Elmer Guerrero, Daniel De La Torre Ugarte

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A well-developed transportation network is a necessary condition for a country to derive full benefits from good trade and macroeconomic policies. Road infrastructure plays a key role in the economic development of rural areas of developing countries; where agriculture is the main economic activity. The ability to move agricultural production from the place of production to the market, and then to the place of consumption, greatly influence the economic value of farming activities, and of the resources involved in the production process, i.e., labor and land. Consequently, investment in transportation networks contributes to enhance or overcome the natural advantages or disadvantages that topography and location have imposed over the agricultural sector. This is of particular importance when dealing with countries, like Peru, with a great topographic diversity. The objective of this research is to estimate the impacts of road infrastructure on the performance of the agricultural sector. Specific variables of interest are changes in travel time, shifts of production for self-consumption to production for the market, changes in farmers income, and impacts on the diversification of the agricultural sector. In the study, a cross-section model with instrumental variables is the central methodological instrument. The data is obtained from agricultural and transport geo-referenced databases, and the instrumental variable specification utilized is based on the Kruskal algorithm. The results show that the expansion of road connectivity reduced farmers' travel time by an average of 3.1 hours and the proportion of output sold in the market increases by up to 40 percentage points. The increase in connectivity has an unexpected increase in the districts index of diversification of agricultural production. The results are robust to the inclusion of year and region fixed-effects, and to control for geography (i.e., slope and altitude), population variables, and mining activity. Other results are also very eloquent. For example, a clear positive impact can be seen in access to local markets, but this does not necessarily correlate with an increase in the production of the sector. This can be explained by the fact that agricultural development not only requires provision of roads but additional complementary infrastructure and investments intended to provide the necessary conditions so that producers can offer quality products (improved management practices, timely maintenance of irrigation infrastructure, transparent management of water rights, among other factors). Therefore, complementary public goods are needed to enhance the effects of roads on the welfare of the population, beyond enabling them to increase their access to markets.

Keywords: agriculture devolepment, market access, road connectivity, regional development

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Authors: Noor Ashikin Omar

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The rapid growth and advancement in information and communication technology (ICT) at a global scene has greatly influenced and revolutionised interaction amongst society. The use of ICT has become second nature in managing everyday lives, particularly in the education environment. Traditional learning methods of using blackboards and chalks have been largely improved by the use of ICT devices such as interactive whiteboards and computers in school. This paper aims to explore the impacts of virtual learning environments (VLE) on teacher’s pedagogy and student’s learning in primary school settings. The research was conducted in two phases. Phase one of this study comprised a short interview with the school’s senior assistants to examine issues and challenges faced during planning and implementation of FrogVLE in their respective schools. Phase two involved a survey of a number of questionnaires directed to three major stakeholders; the teachers, students and parents. The survey intended to explore teacher’s and student’s perspective and attitude towards the use of VLE as a teaching and learning medium and as a learning experience as a whole. In addition, the survey from parents provided insights on how they feel towards the use of VLE for their child’s learning. Collectively, the two phases enable improved understanding and provided observations on factors that had affected the implementation of the VLE into primary schools. This study offers the voices of the students which were frequently omitted when addressing innovations as well as teachers who may not always be heard. It is also significant in addressing the importance of teacher’s pedagogy on students’ learning and its effects to enable more effective ICT integration with a student-centred approach. Finally, parental perceptions in the implementation of VLE in supporting their children’s learning have been implicated as having a bearing on educational achievement. The results indicate that the all three stakeholders were positive and highly supportive towards the use of VLE in schools. They were able to understand the benefits of moving towards the modern method of teaching using ICT and accept the change in the education system. However, factors such as condition of ICT facilities at schools and homes as well as inadequate professional development for the teachers in both ICT skills and management skills hindered exploitation of the VLE system in order to fully utilise its benefits. Social influences within different communities and cultures and costs of using the technology also has a significant impact. The findings of this study are important to the Malaysian Ministry of Education because it informs policy makers on the impact of the Virtual Learning Environment (VLE) on teacher’s pedagogy and learning of Malaysian primary school children. The information provided to policy makers allows them to make a sound judgement and enables an informed decision making.

Keywords: attitudes towards virtual learning environment (VLE), parental perception, student's learning, teacher's pedagogy

Procedia PDF Downloads 206