Search results for: differential item functioning

Authors: Barenten Suciu

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In this paper, a theoretical study on the forced vibration of one degree of freedom system equipped with inerter, working under load-type or displacement-type excitation, is presented. Differential equations of movement are solved under cosinusoidal excitation, and explicit relations for the magnitude, resonant magnitude, phase angle, resonant frequency, and critical frequency are obtained. Influence of the inertance and damping on these dynamic characteristics is clarified. From the obtained results, one concludes that the inerter increases the magnitude of vibration and the phase angle of the damped mechanical system. Moreover, the magnitude ratio and difference of phase angles are not depending on the actual type of excitation. Consequently, such kind of similitude allows for the comparison of various theoretical and experimental results, which can be broadly found in the literature.

Keywords: displacement-type excitation, inerter, load-type excitation, one degree of freedom vibration, parallel connection

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Authors: Abdiwahab Guled

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Autism spectrum disorder (ASD) is a neurodevelopmental disorder that emanates from a broad range of conditions, which affect the communication skills, social skills. It causes restrictive and repetitive behaviors to individuals. The number of children with ASD is an increasing prevalence around the world. Virtual reality (VR) is an assistive technology, which puts the learner in an immersive learning environment. It allows the learner to interact with that environment in a seemingly real or physical way using special electronic equipment, such as headsets. This exploratory study examines the potential benefits that VR may provide to improving the communication skills of children with ASD. Educating a child with ASD is challenging because access to services, resources, and support for autistic children is inadequate. Therefore, this study intends to investigate the challenges of teaching children with ASD and how VR might help teachers to improve the communication skills of these children with ASD. Online research and literature review were used as a method to gather previously published studies to identify the research gap and provide the groundwork for future studies. Results show that VR offers potential benefits to improving the communication skills of children with ASD but there is a gap in our understanding of the functionalities of all the features of VR technology and how we can utilize it to improve the communication skills of children with ASD. Communication is a broad subject and it is impossible for one study to evidently define the speech challenges of autistic children and provide an irrefutable solution. Therefore, this study proposes further research to dissect how can VR be used to improve the different communication challenges that impede the everyday functioning of autistic children.

Keywords: Autism spectrum disorder (ASD), autistic, Asperger, Disorder-Not Otherwise Specified (PDD-NOS), virtual reality (VR).

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Authors: Shao-Yuan Huang

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We study the shape of the bifurcation curve of positive solutions for the semipositone problem with the Minkowski-curvature operator. The Minkowski-curvature problem plays an important role in certain fundamental issues in differential geometry and in the special theory of relativity. In addition, it is well known that studying the multiplicity of positive solutions is equivalent to studying the shape of the bifurcation curve. By the shape of the bifurcation curve, we can understand the change in the multiplicity of positive solutions with varying parameters. In this paper, our main technique is a time-map method used in Corsato's PhD Thesis. By this method, studying the shape of the bifurcation curve is equivalent to studying the shape of a certain function T with improper integral. Generally speaking, it is difficult to study the shape of T. So, in this paper, we consider two cases that the nonlinearity is convex or concave. Thus we obtain the following results: (i) If f''(u) < 0 for u > 0, then the bifurcation curve is C-shaped. (ii) If f''(u) > 0 for u > 0, then there exists η>β such that the bifurcation curve does not exist for 0 η. Furthermore, we prove that the bifurcation is C-shaped for L > η under a certain condition.

Keywords: bifurcation curve, Minkowski-curvature problem, positive solution, time-map method

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Authors: Johannes J. Schneider, Mathias S. Weyland, Peter Eggenberger Hotz, William D. Jamieson, Oliver Castell, Alessia Faggian, Rudolf M. Füchslin

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In the description of the origin of life, there are still some open gaps, e.g., the formation of macromolecules cannot be fully explained so far. The Kauffman model proposes the existence of autocatalytic sets of macromolecules which mutually catalyze reactions leading to each other’s formation. Usually, this model is simulated in one well-stirred pot only, with a continuous inflow of small building blocks, from which larger molecules are created by a set of catalyzed ligation and cleavage reactions. This approach represents the picture of the primordial soup. However, the conditions on the early Earth must have differed geographically, leading to spatially different outcomes whether a specific reaction could be performed or not. Guided by this picture, the Kauffman model is simulated in a large number of containers in parallel, with neighboring containers being connected by diffusion. In each container, only a subset of the overall reaction set can be performed. Under specific conditions, this approach leads to a larger probability for the existence of an autocatalytic metabolism than in the original Kauffman model.

Keywords: agglomeration, autocatalytic set, differential equation, Kauffman model

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Authors: Raif Parlakkaya, Mustafa Nihat Demirci, Mehmet Nuri Salur

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Environmental pollution has detrimental effects on the quality of our life and its scope has reached such an extent that measures are being taken both at the national and international levels to reduce, prevent and mitigate its impact on social, economic and political spheres. Therefore, awareness of environmental problems has been increasing among stakeholders and accordingly among companies. It is seen that corporate reporting is expanding beyond environmental performance. Primary purpose of publishing an environmental report is to provide specific audiences with useful, meaningful information. This paper is intended to analyze the extent and qualification of environmental disclosures of Turkish publicly quoted firms and see how it varies from one sector to another. The data for the study were collected from annual activity reports of companies, listed on the corporate governance index (BIST-XKURY) of Istanbul Stock Exchange. Content analysis was the research methodology used to measure the extent of environmental disclosure. Accordingly, 2015 annual activity reports of companies that carry out business in some particular fields were acquired from Capital Market Board, websites of Public Disclosure Platform and companies’ own websites. These reports were categorized into five main aspects: Environmental policies, environmental management systems, environmental protection and conservation activities, environmental awareness and information on environmental lawsuits. Subsequently, each component was divided into several variables related to what each firm is supposed to disclose about environmental information. In this context, the nature and scope of the information disclosed on each item were assessed according to five different ways (N.I: No Information; G.E.: General Explanations; Q.E.: Qualitative Detailed Explanations; N.E.: Quantitative (numerical) Detailed Explanations; Q.&N.E.: Both Qualitative and Quantitative Explanations).

Keywords: environmental accounting, disclosure, corporate governance, content analysis

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Authors: Oveis Abedinia, Noradin Ghadimi, Nasser Mikaeilvand, Roza Poursoleiman, Asghar Poorfaraj

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In this paper a robust Fuzzy Proportional Integral Differential (PID) controller is applied to multi-machine power system based on Modified Shuffled Frog Leaping (MSFL) algorithm. This newly proposed controller is more efficient because it copes with oscillations and different operating points. In this strategy the gains of the PID controller is optimized using the proposed technique. The nonlinear problem is formulated as an optimization problem for wide ranges of operating conditions using the MSFL algorithm. The simulation results demonstrate the effectiveness, good robustness and validity of the proposed method through some performance indices such as ITAE and FD under wide ranges operating conditions in comparison with TS and GSA techniques. The single-machine infinite bus system and New England 10-unit 39-bus standard power system are employed to illustrate the performance of the proposed method.

Keywords: fuzzy PID, MSFL, multi-machine, low frequency oscillation

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Authors: Kashif Jaeel, Bingru Huang

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Stress-induced accumulation of ethylene exacerbates drought damages in plants, and suppressing stress induction of ethylene may promote plant tolerance to heat stress. The objective of this study was to investigate the effects of endophytic bacteria (Paraburkholderia aspalathi) with 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzymes in suppressing ethylene production on plant tolerance to heat stress and underlying physiological mechanisms of P. aspalathi-regulation in creeping bentgrass (Agrostis stolonifera). A novel strain of P. aspalathi, ‘WSF23’, with ACC deaminase activity was used to inoculate the roots of plants (cv. ‘Penncross’) subjected to heat stress in controlled-environment chambers. Inoculation with WSF23 bacteria resulted in improved shoot and root growth during heat stress. The differential changes in metabolite regulation due to the bacterial inoculation could contribute to ACC deamination bacteria-improved heat tolerance in cool-season grass species.

Keywords: rhizobacteria, grass, heat, plant metabolism, soil bacteria

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Authors: Pavlo Selyshchev, Samuel Akintunde

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A theoretical approach to consider formation of chemical compound layer at the interface between initial substances A and B due to the interfacial interaction and diffusion is developed. It is considered situation when speed of interfacial interaction is large enough and diffusion of A-atoms through AB-layer is much more then diffusion of B-atoms. Atoms from A-layer diffuse toward B-atoms and form AB-atoms on the surface of B-layer. B-atoms are assumed to be immobile. The growth kinetics of the AB-layer is described by two differential equations with non-linear coupling, producing a good fit to the experimental data. It is shown that growth of the thickness of the AB-layer determines by dependence of chemical reaction rate on reactants concentration. In special case the thickness of the AB-layer can grow linearly or parabolically depending on that which of processes (interaction or the diffusion) controls the growth. The thickness of AB-layer as function of time is obtained. The moment of time (transition point) at which the linear growth are changed by parabolic is found.

Keywords: phase formation, binary systems, interfacial reaction, diffusion, compound layers, growth kinetics

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Authors: Ishit Sheth, Chandrasekhar Jinendran, Chinmaya Ranjan Sahu

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A fourteen degree of freedom (DOF) ride and handling control mathematical model is developed for a car using generalized boltzmann hamel equation which will create a basis for design of ride and handling controller. Mathematical model developed yield equations of motion for non-holonomic constrained systems in quasi-coordinates. The governing differential equation developed integrates ride and handling control of car. Model-based systems engineering approach is implemented for simulation using matlab/simulink, vehicle’s response in different DOF is examined and later validated using commercial software (ADAMS). This manuscript involves detailed derivation of full car vehicle model which provides response in longitudinal, lateral and yaw motion to demonstrate the advantages of the developed model over the existing dynamic model. The dynamic behaviour of the developed ride and handling model is simulated for different road conditions.

Keywords: Full Vehicle Model, MBSE, Non Holonomic Constraints, Boltzmann Hamel Equation

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Authors: H.Karnezi, K. Tierney

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Childhood fears that persist over time and interfere with the children’s normal functioning may have detrimental effects on their social and emotional development. Cognitive behavior therapy is considered highly effective in treating fears and anxieties. However, given that many childhood fears are based on fantasy, the applicability of CBT may be hindered by cognitive immaturity. Furthermore, a lack of motivation to engage in therapy is another commonly encountered obstacle. The purpose of this study was to introduce and evaluate a more developmentally appropriate intervention model, specifically designed to provide phobic children with the motivation to overcome their fears. To this end, principles and techniques from cognitive and behavior therapies are incorporated into the ‘Drama in Education’ model. The Cognitive Behaviour Drama (CBD) method involves using the phobic children’s creativity to involve them in the therapeutic process. The children are invited to engage in exciting fictional scenarios tailored around their strengths and special interests. Once their commitment to the drama is established, a problem that they will feel motivated to solve is introduced. To resolve it, the children will have to overcome a number of obstacles culminating in an in vivo confrontation with the fear stimulus. The study examined the application of the CBD model in three single cases. Results in all three cases shown complete elimination of all fear-related symptoms. Preliminary results justify further evaluation of the Cognitive Behaviour Drama model. It is time and cost-effective, ensuring the clients' immediate engagement in the therapeutic process.

Keywords: phobias, autism, intervention, drama

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Authors: Priya Kulkarni, Soumya Koppikar, Datta Shinde, Shantanu Deshpande, Narendrakumar Wagh, Abhay Harsulkar

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Osteoarthritis (OA) is associated with multiple and overlapping aetiologies. IL-1β is produced by stressed tissue and known to aggravate disease pathologies. We selected 10 patients with elevated IL-1β in their synovial fluids (SF). We hypothesized IL-1β as nodal-point connecting different pathologies. IL-1β was higher in all meniscal tear (MT) patients perhaps as the earliest response to injury. Since MT above age of 30 leads to OA in less than 5 years, it is attributed that IL-1β modulates OA pathology. Among all bilateral OA patients, an interesting case operated for Total-Knee-Replacement revealed differential cartilage degeneration demonstrating strong association with higher IL-1β. Symptoms like acute-pain, effusion and redness were correlated with higher IL-1β and NO (Nitric-oxide). However, higher IL-1β was also found without typical-inflammation characterized by infiltration of neutrophils and macrophages. Cultured synoviocytes responded to IL-1β by releasing NO. In conclusion, IL-1β in SF acquires central position influencing different OA pathologies and aetiologies.

Keywords: IL-1β, meniscal tear, osteoarthritis, synovial fluid

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Authors: Nageeb A. H. Haroun, Sabyasachi Mondal, Precious Sibanda

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The effects of thermal radiation, Soret and Dufour parameters on mixed convection and nanofluid flow over a stretching sheet in the presence of a magnetic field are investigated. The flow is subject to temperature dependent viscosity and a chemical reaction parameter. It is assumed that the nanoparticle volume fraction at the wall may be actively controlled. The physical problem is modelled using systems of nonlinear differential equations which have been solved numerically using a spectral relaxation method. In addition to the discussion on heat and mass transfer processes, the velocity, nanoparticles volume fraction profiles as well as the skin friction coefficient are determined for different important physical parameters. A comparison of current findings with previously published results for some special cases of the problem shows an excellent agreement.

Keywords: non-isothermal wedge, thermal radiation, nanofluid, magnetic field, soret and dufour effects

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Authors: Morgan Dempsey, Sam Lewis, Maggie Pierce, Alex Goodman

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This research investigates the impact of equine-assisted therapy programs on occupational engagement for children with intellectual and developmental disabilities. There is a general lack of evidence for equine-based services for this population, so this research aims to decrease gaps in the current literature. To gain comprehensive insight, data will be collected from both the child and their caregiver. This study takes a qualitative approach utilizing online surveys and in-person guided interviews. The participants are individuals ages 4-17 with a diagnosed intellectual or developmental disability who are currently participating in a PATH int. certified equine-assisted therapy program. Also, caregivers of individuals who meet this criterion are included. This study decreases gaps in the literature by providing comprehensive data regarding the impacts of these services on occupational engagement. The addressed domains are physical, behavioral, emotional, and social functioning, as well as overall activity engagement and impacts in everyday life. With a better understanding of how equine-assisted therapy affects relevant outcomes for children with disabilities, an increased number of occupational therapists can implement these uniquely effective services while adhering to standards of evidence-based practice. Ultimately, this research strives to contribute to generalizable data in occupational therapy by supporting the implementation of equine-assisted services for children with intellectual and/or developmental disabilities and their caregivers/families.

Keywords: occupational therapy, pediatric, rehabilitation, hippotherapy

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Authors: Treder Natalia, Siemiński Mariusz

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Takotsubo cardiomyopathy (TC) is a recently defined clinical entity. First described by Japanese researchers, today is diagnosed worldwide in 1-2% of patients admitted with the preliminary diagnosis of Acute Coronary Syndrome. The etiology of takotsubo cardiomyopathy remains still largely unknown. Currently, the most likely cause of takotsubo is direct cytotoxicity caused by catecholamine surge triggered by emotional stress. There is a strong relation between recent severe emotional stress and TC. The aim of this study was to analysis the role of stress and personality as a risk factor of TT. The presented research involves 35 people who are diagnosed TC. All patients were women, mean age 60 years. The methods used in the research are popular psychological tests: Perceived Stress Scale, DS14 scale to measure type D personality, The Neo-Five Factor Inventory of Personality and psychological interview. The obtained results prove that stress events may directly precede or even release TC. The stressful events occurred directly before the symptoms in 75% examined. 65% assessed their family life as very stressful. Examiners have also a high level of experienced stress. Only 25% of the TC were classified as having type D personality but they have a high level of negative affectivity. The subjects had a high level of extraversion, openness to experiences and an average level of neuroticism. The results suggested that such a type of personality profile may predispose to the development of takotsubo cardiomyopathy. Patients with TT are the individuals who reveal joint tendency to the experience of negative emotions and very stressful family life.

Keywords: stress, personality trails, familiar problems, Takotsubo cardiomyopathy

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Authors: Fatemeh Alsadat Miri, Morteza Ehsani, Hossein Ali Khonakdar, Behjat Kavyani

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This paper studies the effect of nano glass flakes on morphology, dynamic-mechanical properties, and crystallization behavior of poly (ethylene terephthalate) (PET). The concentration of nano glass flakes was varied from 0.5, 1, 2, and 3% wt of the total formulation. Scanning electron microscopy (SEM) micrographs showed the poor distribution of nano-glass flake particles in PET, as well as low adhesion of particles to the polymer matrix. According to differential scanning calorimetry (DSC), the crystallization rate and crystallization temperature of PET were increased by the addition of nano glass flakes. The crystallization rate of PET was increased from 31.41% to 34.25% by the incorporation of 1%wt of nano glass flakes. Based on the results of the dynamic-mechanical analysis, the storage modulus of PET gets increased by adding nano glass flakes, especially below glass transition temperature (Tg). The glass transition of PET did not change remarkably with the addition of nano glass flakes. Moreover, the use of nano glass flakes reduced the impact strength of PET.

Keywords: PET, nano glass flakes, morphology, crystallization

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Authors: Nemanja D. Kidzin

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The field of personality change has recently garnered increased attention, while the psychology of acting has remained relatively understudied. This research tried to contribute to the both research field by investigating whether the process of acting can lead to personality changes in acting students and, if so, in what manner. It was hypothesized that significant differences would be observed in self-reported personality traits of acting students between the beginning and end of their role preparation. The study also examined potential moderator variables, including the reported personality traits of the roles portrayed by the students, empathy, disintegration, and years of formal acting education. The sample comprised 47 students of acting from the Faculty of Dramatic Arts (first to fourth-year) and the Faculty of Modern Arts (first-year students only). The research involved two waves of testing, conducted at the beginning (T1) and end (T2) of the semester. Personality traits (measured using the HEXACO-60 self-report version), empathy (measured using the Questionnaire of Cognitive and Affective Empathy, QCAE), and disintegration (measured using the DELTA9, 10-item version) were assessed at both T1 and T2, while the personality of the role (measured using the HEXACO-60 observer version) was assessed at T2. Repeated-measures t-tests revealed significant differences in emotionality and conscientiousness between T1 and T2. Additionally, an index of absolute personality change was significantly different from 0 for all traits, indicating personality change. The average test-retest correlation for HEXACO traits was 0.57, lower than that proposed in similar research. However, the personality of the role, empathy, and disintegration did not explain the changes in students' personality traits as moderator variables. The magnitude of personality change was highest among fourth-year students, with no significant differences observed among the remaining three years of study. Overall, the findings suggest the presence of personality changes or trait variability in acting students. However, these changes cannot be conclusively attributed to the process of role preparation. Further research with more stringent methodologies is needed to better understand the role of acting in personality change.

Keywords: personality change, psychology of acting, empathy, disintegraton

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Authors: Navneet Dabra, Baljinder Kaur, Lakhbir Singh, V. Annapu Reddy, R. Nath, Dae-Yong Jeong, Jasbir S. Hundal

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The ferroelectric properties of fused potassium nitrate (KNO3)- polyvinyl alcohol (PVA) composite films have been investigated. The composite films of KNO3-PVA have been prepared by solvant cast technique and then fused over the brass substrate. The ferroelectric hysteresis loops (P-E) have been obtained at room temperature using modified Sawyer-Tower circuit. Percentage of back switching and differential dielectric constant has been derived from P-V loops. The x-ray diffraction (XRD) studies confirm the formation of ferroelectric phase (phase III) in these composite films. The AFM and FE-SEM studies have been used to study the surface morphology of these composite films. The values of remanemt polarization, coercive field, back switching, crystallite size, lattice parameters, and surface roughness have been estimated and correlated.

Keywords: ferroelectric polymer composite, remanemt polarization, back switching, crystallite size, lattice parameters and surface roughness

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Authors: Pemika Ketsuwan, Pitt Supaphol, Manit Nithitanakul

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A typical used of ethylene methyl acrylate (EMA) gasket is in the manufacture of optical lens, and often, they are deteriorated rapidly due to high temperature during the process. The objective of this project is to improve the thermal stability of the EMA copolymer gasket by preparing EMA with cellulose and silica composites. Hydroxy propyl methyl cellulose (HPMC) and Carboxy methyl cellulose (CMC) were used in preparing of EMA/cellulose composites and fumed silica (SiO2) was used in preparing EMA/silica composites with different amounts of filler (3, 5, 7, 10, 15 wt.%), using a twin screw extruder at 160 °C and the test specimens were prepared by the injection molding machine. The morphology and dispersion of fillers in the EMA matrix were investigated by field emission scanning electron microscopy (FESEM). The thermal stability of the composite was determined by thermal gravimetric analysis (TGA), and differential scanning calorimeter (DSC). Mechanical properties were evaluated by tensile testing. The developed composites were found to enhance thermal and mechanical properties when compared to that of the EMA copolymer alone.

Keywords: ethylene methyl acrylate, HPMC, Silica, Thermal stability

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Authors: A. Kojah, A. Nacaroğlu

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Single phase transmission lines are used to transfer data or energy between two users. Transient conditions such as switching operations and short circuit faults cause the generation of the fluctuation on the waveform to be transmitted. Spatial voltage distribution on the single phase transmission line may change owing to the position and duration of the short circuit fault in the system. In this paper, the state space representation of the single phase transmission line for short circuit fault and for various types of terminations is given. Since the transmission line is modeled in time domain using distributed parametric elements, the mathematical representation of the event is given in state space (time domain) differential equation form. It also makes easy to solve the problem because of the time and space dependent characteristics of the voltage variations on the distributed parametrically modeled transmission line.

Keywords: energy transmission, transient effects, transmission line, transient voltage, RLC short circuit, single phase

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Authors: Amro Matyori, Fatimah Sherbeny, Askal Ali, Olayiwola Popoola

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Objectives: The study evaluated the impact of COVID-19 on anxiety levels in the general population in the United States. Methods: The study used an online questionnaire. It adopted the Generalized Anxiety Disorder Assessment (GAD-7) instrument. It is a self-administered scale with seven items used as a screening tool and severity measure for generalized anxiety disorder. The participants rated the frequency of anxiety symptoms in the last two weeks on a Likert scale, which ranges from 0-3. Then the item points are summed to provide the total score. Results: Thirty-two participants completed the questionnaire. Among them, 24 (83%) females and 5 (17%) males. The age range of 18-24-year-old represented the most respondents. Only one of the participants tested positive for the COVID-19, and 39% of them, one of their family members, friends, or colleagues, tested positive for the coronavirus. Moreover, 10% have lost a family member, a close friend, or a colleague because of COVID-19. Among the respondents, there were ten who scored approximately five points on the GAD-7 scale, which indicates mild anxiety. Furthermore, eight participants scored 10 to 14 points, which put them under the category of moderate anxiety, and one individual who was categorized under severe anxiety scored 15 points. Conclusions: It is identified that most of the respondents scored the points that put them under the mild anxiety category during the COVID-19 pandemic. It is also noticed that severe anxiety was the lowest among the participants, and people who tested positive and/or their family members, close friends, and colleagues were more likely to experience anxiety. Additionally, participants who lost friends or family members were also at high risk of anxiety. It is obvious the COVID-19 outcomes and too much thinking about the pandemic put people under stress which led to anxiety. Therefore, continuous assessment and monitoring of psychological outcomes during pandemics will help to establish early well-informed interventions.

Keywords: anxiety and covid-19, covid-19 and mental health outcomes, influence of covid-19 on anxiety, population and covid-19 impact on mental health

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Authors: Oloyede John Adebayo

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This paper tested a variant of the monetary model of exchange rate determination, called Frankel’s Capital Account Monetary Model (CAAM) based on Real Interest Rate Differential, on the floating exchange rate experiences of three developing countries of Africa; viz: Ghana, Nigeria and the Gambia. The study adopted the Auto regressive Instrumental Package (AIV) and Almon Polynomial Lag Procedure of regression analysis based on the assumption that the coefficients follow a third-order Polynomial with zero-end constraint. The results found some support for the CAAM hypothesis that exchange rate responds proportionately to changes in money supply, inversely to income and positively to interest rates and expected inflation differentials. On this basis, the study points the attention of monetary authorities and researchers to the relevance and usefulness of CAAM as appropriate tool and useful benchmark for analyzing the exchange rate behaviour of most developing countries.

Keywords: exchange rate, monetary model, interest differentials, capital account

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Authors: Huang Ying

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The present study was to investigate factors affecting children's improvement through the first two years of elementary school on a population-based sample of children with autism in Taiwan. All the children were diagnosed with autism spectrum disorder (ASD) by clinical psychologists according to DSM-IV. Children's development was assessed by the Vineland Adaptive Behavior Scales-Chinese version (VABS-C) on the first and the third grade. Children's improvement was measured by the difference between the standardized total score of the third and the first year. In Taiwan, school-age children with special-education needs will be arranged into different classes, including normal classes (NC), resource classes (RC), and special classes (SC) by the government. Therefore, type of class was one of the independent variables. Moreover, as early intervention is considered to be crucial, the earliest age when intervention begins was collected from parents. Attention was also included in the analysis. Teachers were asked to evaluate children's attention with a 3-item Likert Scale. The frequency of paying attention to the class or the task was recorded and scores were summed up. Additionally, standardized scores of the VABS-C in the first grade were used as pretest scores representing children's developmental level at the beginning of elementary school. Multiple regression was conducted with improvement as the dependent variable. Results showed that children in special classes had smaller improvement compared to those in normal or resource classes. Attention positively predicted improvement yet the effect of earliest intervention age was not significant. Furthermore, scores in the first grade negatively predicted improvement, which indicated that children with higher developmental levels would make less progress in the following years. Results were to some degree consistent with previous findings through meta-analysis that the effectiveness of conventional intervention methods lacked sufficient evidence to support.

Keywords: attention, early intervention, elementary school, special education in Taiwan

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Authors: Tahira Pirzada, Zahra Ashrafi, Saad Khan

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We present a facile and sustainable solid templating approach to fabricate highly porous, flexible and superhydrophobic aerogels of composite nanofibers of cellulose diacetate and silica which are produced through sol gel electrospinning. Scanning electron microscopy, contact angle measurement, and attenuated total reflection-Fourier transform infrared spectrometry are used to understand the structural features of the resultant aerogels while thermogravimetric analysis and differential scanning calorimetry demonstrate their thermal stability. These aerogels exhibit a self-supportive three-dimensional network abundant in large secondary pores surrounded by primary pores resulting in a highly porous structure. Thermal crosslinking of the aerogels has further stabilized their structure and flexibility without compromising on the porosity. Ease of processing, thermal stability, high porosity and oleophilic nature of these aerogels make them promising candidate for a wide variety of applications including acoustic and thermal insulation and oil and water separation.

Keywords: hybrid aerogels, sol-gel electrospinning, oil-water separation, nanofibers

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Authors: Parvin Mirmiran, Zahra Bahadoran, Sahar Mirzae, Fereidoun Azizi

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Background and aim: Lifestyle factors, especially dietary intakes play an important role in metabolism of lipids and lipoproteins. In this study, we assessed the association between dietary factors and 3-year changes of serum triglycerides (TG), HDL-C and the atherogenic index of plasma among Iranian adults. This longitudinal study was conducted on 1938 subjects, aged 19-70 years, who participated in the Tehran Lipid and Glucose Study. Demographics, anthropometrics and biochemical measurements including serum TG were assessed at baseline (2006-2008) and after a 3-year follow-up (2009-2011). Dietary data were collected by using a 168-food item, validated semi-quantitative food frequency questionnaire at baseline. The risk of hypertriglyceridemia in the quartiles of dietary factors was evaluated using logistic regression models with adjustment for age, gender, body mass index, smoking, physical activity and energy intakes. Results: Mean age of the participants at baseline was 41.0±13.0 y. Mean TG and HDL-C at baseline was 143±86 and 42.2±10.0 mg/dl, respectively. Three-year change of serum TG were inversely related energy intake from phytochemical rich foods, whole grains, and legumes (P<0.05). Higher intakes compared to lower ones of dietary fiber and phytochemical-rich foods had similar impact on decreased risk of hyper-triglyceridemia (OR=0.58, 95% CI=0.34-1.00). Higher- compared to lower-dietary sodium to potassium ratios (Na/K ratio) increased the risk of hypertriglyceridemia by 63% (OR=0.1.63, 95% CI= 0.34-1.00). Conclusion: Findings showed that higher intakes of fiber and phytochemical rich foods especially whole grain and legumes could have protective effects against lipid disorders; in contrast higher sodium to potassium ratio had undesirable effect on triglycerides.

Keywords: lipid disorders, hypertriglyceridemia, diet, food science

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Authors: Sylvia Tumelo Nthutang, Nehemiah Mavetera

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Educational institutions are under pressure from their competitors. Regulators and community groups need educational institutions to adopt appropriate business and organizational practices. Globally, educational institutions are now using e-learning as the best teaching and learning approach. E-learning is becoming the center of attention to the learning institutions, educational systems and software inventors. North-West University (NWU) is currently using eFundi, a Learning Management System (LMS). LMS are all information systems and procedures that adds value to students learning and support the learning material in text or any multimedia files. With various e-learning tools, students would be able to access all the materials related to the course in electronic copies. The study was tasked with identifying the e-learning components at the NWU, Mafikeng campus. Quantitative research methodology was considered in data collection and descriptive statistics for data analysis. The Activity Theory (AT) was used as a theory to guide the study. AT outlines the limitations amongst e-learning at the macro-organizational level (plan, guiding principle, campus-wide solutions) and micro-organization (daily functioning practice, collaborative transformation, specific adaptation). On a technological environment, AT gives people an opportunity to change from concentrating on computers as an area of concern but also understand that technology is part of human activities. The findings have identified the university’s current IT tools and knowledge on e-learning elements. It was recommended that university should consider buying computer resources that consumes less power and practice e-learning effectively.

Keywords: e-learning, information and communication technology (ICT), teaching, virtual learning environment

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Authors: Amirali Ebrahimi, T. A. G. Langrish

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The effect of various humidities on process yields and degrees of crystallinity for spray-dried powders from spray drying of lactose with humid air in a straight-through system have been studied. It has been suggested by Williams–Landel–Ferry kinetics (WLF) that a higher particle temperature and lower glass-transition temperature would increase the crystallization rate of the particles during the spray-drying process. Freshly humidified air produced by a Buchi-B290 spray dryer as a humidifier attached to the main spray dryer decreased the particle glass-transition temperature (Tg), while allowing the particle temperature (Tp) to reach higher values by using an insulated drying chamber. Differential scanning calorimetry (DSC) and moisture sorption analysis were used to measure the degree of crystallinity for the spray-dried lactose powders. The results showed that higher Tp-Tg, as a result of applying humid air, improved the process yield from 21 ± 4 to 26 ± 2% and crystallinity of the particles by decreasing the latent heat of crystallization from 43 ± 1 to 30 ± 11 J/g and the sorption peak height from 7.3 ± 0.7% to 6 ± 0.7%.

Keywords: lactose, crystallization, spray drying, humid air

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Authors: Leilani Forby, Farid Pazhoohi, Alan Kingstone

Abstract:

There is abundant research on the nature and content of mind wandering (MW) in neurotypical (NT) adults, however, there is little to no research in these areas on autistic individuals. The objective of the current study was to uncover any differences between low and high autistic trait individuals in their MW. In particular, we examined their attitudes toward, and the themes and temporal dimensions (past, present, future) of, their MW episodes. For our online study, we recruited 518 students (394 women and 124 men), between the ages of 18 and 51 years (M = 20.93, SD = 3.40) from the undergraduate Human Subject Pool at the University of British Columbia. Participants completed the Short Imaginal Processes Inventory (SIPI), which includes the three subscales Positive-Constructive Daydreaming (SIPI-PC), Guilt and Fear of Failure Daydreaming (SIPI-GFF), and Poor Attentional Control (SIPI-PAC). Participants also completed the Past (IPI-past) and Present (IPI-present) subscales of the Imaginal Processes Inventory (IPI), the Deliberate (MW-D) and Spontaneous (MW-S) Mind Wandering scales, the Short Form Perceived Stress Scale (PSS-4), and the 10-item Autism Quotient (AQ-10). Results showed that overall, participant AQ-10 scores were significantly correlated with MW-S, SIPI-GFF, and PSS-4 scores, such that as the number of autistic traits endorsed by participants increased, so did their reports of spontaneous mind wandering, guilt and fear of failure themed day dreaming, and stress levels. This same pattern held for female participants, however, AQ-10 scores were positively correlated with only PSS-4 scores for males. These results suggest that compared to males with autistic traits, MW in females with autistic traits is more similar to individuals with low autistic traits in terms of content and intentionality. Results are discussed in terms of clinical implications, their limitations, and suggested directions for future research.

Keywords: autism, deliberate, mind wandering, spontaneous, perceived stress

Procedia PDF Downloads 142

Authors: Ce Liu, Wei Huo

Abstract:

A nonlinear trajectory tracking controller for quadrotor helicopter based on controlled Lagrangian (CL) method is proposed in this paper. A Lagrangian system with virtual angles as generated coordinates rather than Euler angles is developed. Based on the model, the matching conditions presented by nonlinear partial differential equations are simplified and explicitly solved. Smooth tracking control laws and the range of control parameters are deduced based on the controlled energy of closed-loop system. Besides, a constraint condition for reference accelerations is deduced to identify the trackable reference trajectories by the proposed controller and to ensure the stability of the closed-loop system. The proposed method in this paper does not rely on the division of the quadrotor system, and the design of the control torques does not depend on the thrust as in backstepping or hierarchical control method. Simulations for a quadrotor model demonstrate the feasibility and efficiency of the theoretical results.

Keywords: quadrotor, trajectory tracking control, controlled lagrangians, underactuated system

Procedia PDF Downloads 117

Authors: Fernando G. Torres, Omar P. Troncoso

Abstract:

Quercetin is a naturally occurring polyphenol found in many vegetables, such as onion, with antioxidant properties. It is a dietary component with a documented role in reducing different human cancers. However, its low bioavailability, poor water solubility, and chemical instability limit its applications. Different nano-delivery systems such as nanoparticles, micelles, and nanohydrogels have been studied in order to improve the bioavailability of quercetin. Nanoparticles based on natural polymers such as starch have the advantage of being biocompatible, biodegradable, and non-toxic. In this study, quercetin was loaded into starch nanoparticles using a nanoprecipitation method. Different routes, using sodium tripolyphosphate and Tween® 80 as tensioactive agents, were tested in order to obtain an optimized starch-based nano-delivery system. The characterization of the nanoparticles loaded with quercetin was assessed by Fourier Transform Infrared Spectroscopy, Dynamic Light Scattering, Zeta potential, and Differential scanning calorimetry. UV-vis spectrophotometry was used to evaluate the loading efficiency and capacity of the samples. The results showed that starch-based systems could be successfully used for the nano-delivery of quercetin.

Keywords: starch nanoparticles, nanoprecipitation, quercetin, biomedical applications

Procedia PDF Downloads 136

Authors: A. Tuna, Y. Okumuş, A. T. Seyhan, H. Çelebi

Abstract:

In this study, microfluidization was considered a promising approach to breaking up of carbonized chicken feather fibers (CCFFs) flocs to synthesizing epoxy suspensions containing (1 wt. %) CCFFs. For comparison, CCFF was also treated using sonication. The energy consumed to break up CCFFs in the ethanol was the same for both processes. CCFFs were found to be dispersed in ethanol in a significantly shorter time with the high shear processor. The CCFFs treated by both sonication and microfluidization were dispersed in epoxy by sonication. SEM examination revealed that CCFFs were broken up into smaller pieces using the high shear processor while being not agglomerated. Further, DSC, TMA, and DMA were systematically used to measure thermal properties of the resulting composites. A significant improvement was observed in the composites including CCFFs treated with microfluidization.

Keywords: carbonized chicken feather fiber (CCFF), modulated differential scanning calorimetry (MDSC), modulated thermomechanical analysis (MTMA), thermal properties

Procedia PDF Downloads 312