Search results for: mathematical discussion
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3775

Search results for: mathematical discussion

1075 The Importance of Oral Mucosal Biopsy Selection Site in Areas of Field Change: A Case Report

Authors: Timmis W., Simms M., Thomas C.

Abstract:

This case discusses the management of two floors of mouth (FOM) Squamous Cell Carcinomas (SCC) not identified upon initial biopsy. A 51 year-old male presented with right FOM erythroleukoplakia. Relevant medical history included alcoholic dependence syndrome and alcoholic liver disease. Relevant drug therapy encompassed acamprosate, folic acid, hydroxocobalamin and thiamine. The patient had a 55.5 pack-year smoking history and alcohol dependence from age 14, drinking 16 units/day. FOM incisional biopsy and histopathological analysis diagnosed Carcinoma in situ. Treatment involved wide local excision. Specimen analysis revealed two separate foci of pT1 moderately differentiated SCCs. Carcinoma staging scans revealed no pathological lymphadenopathy, no local invasion or metastasis. SCCs had been excised in completion with narrow margins. MDT discussion concluded that in view of the field changes it would be difficult to identify specific areas needing further excision, although techniques such as Lugol’s Iodine were considered. Further surgical resection, surgical neck management and sentinel lymph node biopsy was offered. The patient declined intervention, primary management involved close monitoring alongside alcohol and smoking cessation referral. Narrow excisional margins can increase carcinoma recurrence risk. Biopsy failed to identify SCCs, despite sampling an area of clinical concern. For gross field change multiple incisional biopsies should be considered to increase chance of accurate diagnosis and appropriate treatment. Coupling of tobacco and alcohol has a synergistic effect, exponentially increasing the relative risk of oral carcinoma development. Tobacco and alcoholic control is fundamental in reducing treatment‑related side effects, recurrence risk and second primary cancer development.

Keywords: alcohol dependence, biopsy, oral carcinoma, tobacco

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1074 Maize Farmers’ Perception of Sharp Practices among Agro-Input Dealers in Ibadan/Ibarapa Agricultural Zone, Oyo State

Authors: Ademola A. Ladele, Peace I. Aburime

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Fake and substandard agricultural inputs pose a serious stumbling block to farm productivity and subsequently improved livelihood. There is, therefore, a need to pave ways for sustainable agriculture and self-sufficiency in food production by proffering solutions to this challenge. Maize farmers' perception of sharp practices among agro-input dealers in Ibadan/Ibarapa agricultural zone in Oyo state was therefore investigated. A multi-stage random sampling technique was used to select registered maize farmers in the Ibadan/Ibarapa agricultural zone of the Oyo State Agricultural Development Programme (OYSADEP). A structured questionnaire was used to collect information on the perception of sharp practices and the effects of sharp practices. A total of seventy-five maize farmers were interviewed. A focus group discussion was organized to identify ways of curbing sharp practices to complement the survey. Data were analyzed using descriptive statistics, Chi-square, and Pearson Product Moment Correlation (PPMC). Forms of sharp practices indicated were sales of expired fertilizers, expired pesticides, expired herbicides, underweight fertilizers, adulterated fertilizers, adulterated herbicides, packs containing broken seeds, infested seeds, lack of truth in labeling/wrong labels, manipulation of measuring scales, and false declaration of hecterages covered by tractor operators. The majority had unfavorable perception of agro-input dealers on sharp practices. A significant relationship was observed between respondents’ level of education and their perception of sharp practices. There were no significant relationships between respondents’ sex, marital status and religion, and their perception of sharp practices. A significant correlation exists between the forms of sharp practices and the perceived effect on agricultural production. It is concluded that the perceived effect of sharp practices was critical and the endemic culture of sharp practices prevailed in agro-input in Ibadan/Ibarapa agricultural zone. A standard regulatory system that will certify and monitor the quality of inputs should be put in place.

Keywords: agricultural productivity, agro-input dealers, maize farmers, sharp practices

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1073 Application of Computational Flow Dynamics (CFD) Analysis for Surge Inception and Propagation for Low Head Hydropower Projects

Authors: M. Mohsin Munir, Taimoor Ahmad, Javed Munir, Usman Rashid

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Determination of maximum elevation of a flowing fluid due to sudden rejection of load in a hydropower facility is of great interest to hydraulic engineers to ensure safety of the hydraulic structures. Several mathematical models exist that employ one-dimensional modeling for the determination of surge but none of these perfectly simulate real-time circumstances. The paper envisages investigation of surge inception and propagation for a Low Head Hydropower project using Computational Fluid Dynamics (CFD) analysis on FLOW-3D software package. The fluid dynamic model utilizes its analysis for surge by employing Reynolds’ Averaged Navier-Stokes Equations (RANSE). The CFD model is designed for a case study at Taunsa hydropower Project in Pakistan. Various scenarios have run through the model keeping in view upstream boundary conditions. The prototype results were then compared with the results of physical model testing for the same scenarios. The results of the numerical model proved quite accurate coherence with the physical model testing and offers insight into phenomenon which are not apparent in physical model and shall be adopted in future for the similar low head projects limiting delays and cost incurred in the physical model testing.

Keywords: surge, FLOW-3D, numerical model, Taunsa, RANSE

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1072 Cultural Heritage in Rural Areas: Added Value for Agro-Tourism Development

Authors: Djurdjica Perovic, Sanja Pekovic, Tatjana Stanovcic, Jovana Vukcevic

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Tourism development in rural areas calls for a discussion of strategies that would attract more tourists. Several scholars argue that rural areas may become more attractive to tourists by leveraging their cultural heritage. The present paper explores the development of sustainable heritage tourism practices in transitional societies of the Western Balkans, specifically targeting Montenegrin rural areas. It addresses the sustainable tourism as a shift in business paradigm, enhancing the centrality of the host community, fostering the encounters with local culture, customs and heritage and minimizing the environmental and social impact. Disseminating part of the results of the interdisciplinary KATUN project, the paper explores the diversification of economic activities related to the cultural heritage of katuns (temporary settlements in Montenegrin mountainous regions where the agricultural households stay with livestock during the summer season) through sustainable agro-tourism. It addresses the role of heritage tourism in creating more dynamic economy of under-developed mountain areas, new employment opportunities, sources of income for the local community and more balanced regional development, all based on the principle of sustainability. Based on the substantial field research (including interviews with over 50 households and tourists, as well as the number of stakeholders such as relevant Ministries, business communities and media representatives), the paper analyses the strategies employed in raising the awareness and katun-sensitivity of both national and international tourists and stimulating their interest in sustainable agriculture, rural tourism and cultural heritage of Montenegrin mountain regions. Studying the phenomena of responsible tourism and tourists’ consumerist consciousness in Montenegro through development of katuns should allow evaluating stages of sustainability and cultural heritage awareness, closely intertwined with the EU integration processes in the country. Offering deeper insight at the relationship between rural tourism, sustainable agriculture and cultural heritage, the paper aims to understand if cultural heritage of the area is valuable for agro-tourism development and in which context.

Keywords: heritage tourism, sustainable tourism, added value, Montenegro

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1071 Prandtl Number Influence Analysis on Droplet Migration in Natural Convection Flow Using the Level Set Method

Authors: Isadora Bugarin, Taygoara F. de Oliveira

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Multiphase flows have currently been placed as a key solution for technological advances in energy and thermal sciences. The comprehension of droplet motion and behavior on non-isothermal flows is, however, rather limited. The present work consists of an investigation of a 2D droplet migration on natural convection inside a square enclosure with differentially heated walls. The investigation in question concerns the effects on drop motion of imposing different combinations of Prandtl and Rayleigh numbers while defining the drop on distinct initial positions. The finite differences method was used to compute the Navier-Stokes and energy equations for a laminar flow, considering the Boussinesq approximation. Also, a high order level set method was applied to simulate the two-phase flow. A previous analysis developed by the authors had shown that for fixed values of Rayleigh and Prandtl, the variation of the droplet initial position at the beginning of the simulation delivered different patterns of motion, in which for Ra≥10⁴ the droplet presents two very specific behaviors: it can travel through a helical path towards the center or define cyclic circular paths resulting in closed paths when reaching the stationary regime. Now, when varying the Prandtl number for different Rayleigh regimes, it was observed that this particular parameter also affects the migration of the droplet, altering the motion patterns as its value is increased. On higher Prandtl values, the drop performs wider paths with larger amplitudes, traveling closer to the walls and taking longer time periods to finally reach the stationary regime. It is important to highlight that drastic drop behavior changes on the stationary regime were not yet observed, but the path traveled from the begging of the simulation until the stationary regime was significantly altered, resulting in distinct turning over frequencies. The flow’s unsteady Nusselt number is also registered for each case studied, enabling a discussion on the overall effects on heat transfer variations.

Keywords: droplet migration, level set method, multiphase flow, natural convection in enclosure, Prandtl number

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1070 Stereotyping of Non-Western Students in Western Universities: Applying Critical Discourse Analysis to Undermine Educational Hegemony

Authors: Susan Lubbers

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This study applies critical discourse analysis to the language used by educators to frame international students of Asian backgrounds in Anglo-Western universities as quiet, shy, passive and unable to think critically. Emphasis is on the self-promoted ‘internationalised’ Australian tertiary context, where negative stereotypes are commonly voiced not only in the academy but also in the media. Parallels are drawn as well with other Anglo-Western educational contexts. The study critically compares the discourse of these persistent negative stereotypes, with in-class and interview discourses of international students of Asian and Western language, cultural and educational backgrounds enrolled in a Media and Popular Culture unit in an Australian university. The focus of analysis of the student discourse is on their engagement in critical dialogic interactions on the topics of culture and interculturality. The evidence is also drawn from student interviews and focus groups and from observation of whole-class discussion participation rates. The findings of the research project provide evidence that counters the myth of student as problem. They point rather to the widespread lack of intercultural awareness of Western educators and students as being at the heart of the negative perceptions of students of Asian backgrounds. The study suggests the efficacy of an approach to developing intercultural competence that is embedded, or integrated, into tertiary programs. The presentation includes an overview of the main strategies that have been developed by the tertiary educator (author) to support the development of intercultural competence of and among the student cohort. The evidence points to the importance of developing intercultural competence among tertiary educators and students. The failure by educators to ensure that the diverse voices, ideas and perspectives of students from all cultural, educational and language backgrounds are heard in our classrooms means that our universities can hardly be regarded or promoted as genuinely internationalised. They will continue as undemocratic institutions that perpetrate persistent Western educational hegemony.

Keywords: critical discourse analysis, critical thinking, embedding, intercultural competence, interculturality, international student, internationalised education

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1069 Control Power in Doubly Fed Induction Generator Wind Turbine with SVM Control Inverter

Authors: Zerzouri Nora, Benalia Nadia, Bensiali Nadia

Abstract:

This paper presents a grid-connected wind power generation scheme using Doubly Fed Induction Generator (DFIG). This can supply power at constant voltage and constant frequency with the rotor speed varying. This makes it suitable for variable speed wind energy application. The DFIG system consists of wind turbine, asynchronous wound rotor induction generator, and inverter with Space Vector Modulation (SVM) controller. In which the stator is connected directly to the grid and the rotor winding is in interface with rotor converter and grid converter. The use of back-to-back SVM converter in the rotor circuit results in low distortion current, reactive power control and operate at variable speed. Mathematical modeling of the DFIG is done in order to analyze the performance of the systems and they are simulated using MATLAB. The simulation results for the system are obtained and hence it shows that the system can operate at variable speed with low harmonic current distortion. The objective is to track and extract maximum power from the wind energy system and transfer it to the grid for useful work.

Keywords: Doubly Fed Induction Generator, Wind Energy Conversion Systems, Space Vector Modulation, distortion harmonics

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1068 Math Word Problems: Context and Achievement

Authors: Irena Smetackova

Abstract:

The important part of school mathematics are word problems which represent the connection between school knowledge and life reality. To find the reasons why students consider word problems to be difficult, it is necessary to take into consideration the motivational settings, besides mathematical knowledge and reading skills. Our goal is to identify whether the familiar or unfamiliar context of math word problem influences solving success rate and if so, whether the reasons are motivational or cognitive. For this purpose, we conducted three steps study in group of fifty pupils 9-10 years old. In the first step, we asked pupils to create ‘the best’ word problems for entered numerical formula. The set of 19 word problems with different contexts were selected. In the second step, pupils were asked to evaluate (without solving) how they like each item and how easy it is for them. The 6 word problems with low preference and low estimated success rate were selected and combined with other 6 problems with high preference and success rate. In the third step, the same pupils were asked to solve the word problems. The analysis showed that pupils attitudes and solving toward word problems varied by the context. The strong gender patterns both in preferred contexts and in estimated success rates were identified however the real success rate did not differ so strongly. The success gap between word problems with and without preferred contexts were stronger than the gap between problems with and without real experience with the context. The hypothesis that motivational factors are more important than cognitive factors was confirmed.

Keywords: mathematics, context of reality, motivation, cognition, word problems

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1067 Is Sodium Channel Nav1.7 an Ideal Therapeutically Analgesic Target? A Systematic Review

Authors: Yutong Wan, John N. Wood

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Introduction: SCN9A encoded Nav1.7 is an ideal therapeutic target with minimal side effects for the pharmaceutical industry because SCN9A variants can cause both human gains of function pain-related mutations and loss of function pain-free mutations. This study reviews the clinical effectiveness of existing Nav1.7 inhibitors, which theoretically should be powerful analgesics. Methods: A systematic review is conducted on the effectiveness of current Nav1.7 blockers undergoing clinical trials. Studies were mainly extracted from PubMed, U.S. National Library of Medicine Clinical Trials, World Health Organization International Clinical Trials Registry, ISRCTN registry platform, and Integrated Research Approval System by NHS. Only studies with full text available and those conducted using double-blinded, placebo controlled, and randomised designs and reporting at least one analgesic measurement were included. Results: Overall, 61 trials were screened, and eight studies covering PF 05089771 (Pfizer), TV 45070 (Teva & Xenon), and BIIB074 (Biogen) met the inclusion criteria. Most studies were excluded because results were not published. All three compounds demonstrated insignificant analgesic effects, and the comparison between PF 05089771 and pregabalin/ibuprofen showed that PF 05089771 was a much weaker analgesic. All three drug candidates only have mild side effects, indicating the potentials for further investigation of Nav1.7 antagonists. Discussion: The failure of current Nav1.7 small molecule inhibitors might attribute to ignorance of the key role of endogenous systems in Nav1.7 null mutants, the lack of selectivity and blocking potency, and central impermeability. The synergistic combination of analgesic drugs, a recent UCL patent, combining a small dose of Nav1.7 blockers and opioids or enkephalinase inhibitors dramatically enhanced the analgesic effects. Conclusion: The current clinical testing Nav1.7 blockers are generally disappointing. However, the newer generation of Nav1.7 targeting analgesics has overcome the major constraints of its predecessors.

Keywords: chronic pain, Nav1.7 blockers, SCN9A, systematic review

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1066 Modeling of the Attitude Control Reaction Wheels of a Spacecraft in Software in the Loop Test Bed

Authors: Amr AbdelAzim Ali, G. A. Elsheikh, Moutaz M. Hegazy

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Reaction wheels (RWs) are generally used as main actuator in the attitude control system (ACS) of spacecraft (SC) for fast orientation and high pointing accuracy. In order to achieve the required accuracy for the RWs model, the main characteristics of the RWs that necessitate analysis during the ACS design phase include: technical features, sequence of operating and RW control logic are included in function (behavior) model. A mathematical model is developed including the various errors source. The errors in control torque including relative, absolute, and error due to time delay. While the errors in angular velocity due to differences between average and real speed, resolution error, loose in installation of angular sensor, and synchronization errors. The friction torque is presented in the model include the different feature of friction phenomena: steady velocity friction, static friction and break-away torque, and frictional lag. The model response is compared with the experimental torque and frequency-response characteristics of tested RWs. Based on the created RW model, some criteria of optimization based control torque allocation problem can be recommended like: avoiding the zero speed crossing, bias angular velocity, or preventing wheel from running on the same angular velocity.

Keywords: friction torque, reaction wheels modeling, software in the loop, spacecraft attitude control

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1065 Autonomy Supportive Coaching to Achieve Health Literacy

Authors: E. Knisel, H. Rupprich, A. Heissel

Abstract:

Health Literacy is defined as the degree to which people have the capacity to obtain and understand information to make health decisions. Illustrated are three levels of health literacy: (1) Functional literacy refers to the transmission of information about e. g. physical activity and nutrition; (2) interactive literacy implies the development of personal and social skills to adopt health-related behaviour and (3) critical health literacy indicates advanced cognitive skills connected with personal empowerment to critically analyse health information, to define self-determined goals and taking action in various situations accordingly. The achievement of the third level refers to self-determination and autonomy which should be outcomes of exercise programs for overweight children as health-related behaviour change will occur and persist if it is autonomously motivated. Method: We adopted a quasi-experimental design with group (autonomy supportive coaching, control) and session (pre-test, intervention, post-test, and follow-up-test). Overweight and obese children and adolescents at the age of 8-14 years (N=40) received a 6-month (20 sessions) exercise program with autonomy supportive coaching implemented by the coaches and sandwiched between pre-test and post-test. All participants (N=92) completed the German version of the Basic Needs Satisfaction Scale Sport and Exercise. Additionally, we assessed the engagement in the exercise program by the MVPA (Moderate-to-Vigorous Physical Activity) and by the adherence and drop-out-rate. Results: Participants in the intervention group perceived their autonomy as moderate in the post-test and the follow-up-test. However, the psychological intervention failed to develop a high autonomy, as both groups show moderate perceived autonomy from the pre-test to the post-test. Participants in the intervention group were higher engaged in MVPA in the exercise program and they attend the program more regularly. Discussion: Young overweight and obese children and adolescents can acquire autonomy using autonomy supporting coaching. However, research identifying the extent they achieve critical health literacy is required to implement an autonomy-supportive coaching style into exercise programs for this target group.

Keywords: autonomy support, coaching, health literacy, health promotion

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1064 Errors and Misconceptions for Students with Mathematical Learning Disabilities: Quest for Suitable Teaching Strategy

Authors: A. K. Tsafe

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The study investigates the efficacy of Special Mathematics Teaching Strategy (SMTS) as against Conventional Mathematics Teaching Strategy (CMTS) in teaching students identified with Mathematics Learning Disabilities (MLDs) – dyslexia, Down syndrome, dyscalculia, etc., in some junior secondary schools around Sokoto metropolis. Errors and misconceptions in learning Mathematics displayed by these categories of students were observed. Theory of variation was used to provide a prism for viewing the MLDs from theoretical perspective. Experimental research design was used, involving pretest-posttest non-randomized approach. Pretest was administered to the intact class taught using CMTS before the class was split into experimental and control groups. Experimental group of the students – those identified with MLDs was taught with SMTS and later mean performance of students taught using the two strategies was sought to find if there was any significant difference between the performances of the students. A null hypothesis was tested at α = 0.05 level of significance. T-test was used to establish the difference between the mean performances of the two tests. The null hypothesis was rejected. Hence, the performance of students, identified with MLDs taught using SMTS was found to be better than their earlier performance taught using CMTS. The study, therefore, recommends amongst other things that teachers should be encouraged to use SMTS in teaching mathematics especially when students are found to be suffering from MLDs and exhibiting errors and misconceptions in the process of learning mathematics.

Keywords: disabilities, errors, learning, misconceptions

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1063 Activation-TV® to Reduce Elderly Loneliness and Insecurity

Authors: Hannele Laaksonen, Seija Nyqvist, Kari Nurmes

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Objectives: In the year 2011 the City of Vaasa started to develop know-how in the technology and the introduction of services for aging people in cooperation with the Polytechnic Novia University of Applied Sciences and VAMK, University of Applied Sciences. The project´s targets included: to help elderly people to maintain their ability to function, to provide them social and physical activities, to prevent their social exclusion, to decrease their feelings of loneliness and insecurity and to develop their technical know-how. Methods: The project was built based on open source code, tailor-made service system and user interface for the elderly living at home and their families, based on the users´ expectations and experiences of services. Activation-TV®-project vas carried out 1.4.2011-31.3.2014. A pilot group of eight elderly persons, who were living at home, were selected to the project. All necessary technical means as well as guidance and teaching equipment were provided to the pilot group. The students of University of Applied Sciences (VAMK, Novia) and employees of Center of Ageing were made all programs to the Activation-TV®. The project group were interviewed after and before intervention. The data were evaluated both qualitatively and quantitatively. Results: The built service includes a video library, a group room for interactive programs and a personal room for bilateral meetings and direct shipment. The program is bilingual and produced in both national languages. The Activation TV® reduced elderly peoples´ (n=8) feelings of emptiness, added mental well-being and quality of life with social contacts. Relatives felt, that they were able to get in to older peoples´ everyday life with Activation TV®. Discussion: The built application was tailored to the model that has not been developed elsewhere in Finland. This model can be copied from one server to another and thus transferred to other municipalities but the program requires its own personnel system management and maintenance as well as program production cooperation between the different actors. This service can be used for the elderly who are living at home without dementia.

Keywords: mental well-being, quality of life, elderly people, Finland

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1062 Quantitative Analysis of the Functional Characteristics of Urban Complexes Based on Station-City Integration: Fifteen Case Studies of European, North American, and East Asian Railway Stations

Authors: Dai Yizheng, Chen-Yang Zhang

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As station-city integration has been widely accepted as a strategy for mixed-use development, a quantitative analysis of the functional characteristics of urban complexes based on station-city integration is urgently needed. Taking 15 railway stations in European, North American, and East Asian cities as the research objects, this study analyzes their functional proportion, functional positioning, and functional correlation with respect to four categories of functional facilities for both railway passenger flow and subway passenger flow. We found that (1) the functional proportion of urban complexes was mainly concentrated in three models: complementary, dominant, and equilibrium. (2) The mathematical model affected by the functional proportion was created to evaluate the functional positioning of an urban complex at three scales: station area, city, and region. (3) The strength of the correlation between the functional area and passenger flow was revealed via data analysis using Pearson’s correlation coefficient. Finally, the findings of this study provide a valuable reference for research on similar topics in other countries that are developing station-city integration.

Keywords: urban complex, station-city integration, mixed-use, function, quantitative analysis

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1061 Modeling of CREB Pathway Induced Gene Induction: From Stimulation to Repression

Authors: K. Julia Rose Mary, Victor Arokia Doss

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Electrical and chemical stimulations up-regulate phosphorylaion of CREB, a transcriptional factor that induces its target gene production for memory consolidation and Late Long-Term Potentiation (L-LTP) in CA1 region of the hippocampus. L-LTP requires complex interactions among second-messenger signaling cascade molecules such as cAMP, CAMKII, CAMKIV, MAPK, RSK, PKA, all of which converge to phosphorylate CREB which along with CBP induces the transcription of target genes involved in memory consolidation. A differential equation based model for L-LTP representing stimulus-mediated activation of downstream mediators which confirms the steep, supralinear stimulus-response effects of activation and inhibition was used. The same was extended to accommodate the inhibitory effect of the Inducible cAMP Early Repressor (ICER). ICER is the natural inducible CREB antagonist represses CRE-Mediated gene transcription involved in long-term plasticity for learning and memory. After verifying the sensitivity and robustness of the model, we had simulated it with various empirical levels of repressor concentration to analyse their effect on the gene induction. The model appears to predict the regulatory dynamics of repression on the L-LTP and agrees with the experimental values. The flux data obtained in the simulations demonstrate various aspects of equilibrium between the gene induction and repression.

Keywords: CREB, L-LTP, mathematical modeling, simulation

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1060 Stability Analysis of DFIG Stator Powers Control Based on Sliding Mode Approach

Authors: Abdelhak Djoudi, Hachemi Chekireb, El Madjid Berkouk

Abstract:

The doubly fed induction generator (DFIG) received recently an important consideration in medium and high power wind energy conversion systems integration, due to its advantages compared to other generators types. The stator power sliding mode control (SPSMC) proves a great efficiency judge against other control laws and schemes. In the SPSMC laws elaborated by several authors, only the slide surface tracking conditions are elaborated using Lyapunov functions, and the boundedness of the DFIG states is never treated. Some works have validated theirs approaches by experiments results in the case of specified machines, but these verifications stay insufficient to generalize to other machines range. Adding to this argument, the DFIG states boundedness demonstration is widely suggested in goal to ensure that in the application of the SPSMC, the states evaluates within theirs tolerable bounds. Our objective in the present paper is to highlight the efficiency of the SPSMC by stability analysis. The boundedness of the DFIG states such as the stator current and rotor flux is discussed. Moreover, the states trajectories are finding using analytical proves taking into consideration the SPSMC gains.

Keywords: Doubly Fed Induction Generator (DFIG), Stator Powers Sliding Mode Control (SPSMC), lyapunov function, stability, states boundedness, trajectories mathematical proves

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1059 Segmentation of the Liver and Spleen From Abdominal CT Images Using Watershed Approach

Authors: Belgherbi Aicha, Hadjidj Ismahen, Bessaid Abdelhafid

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The phase of segmentation is an important step in the processing and interpretation of medical images. In this paper, we focus on the segmentation of liver and spleen from the abdomen computed tomography (CT) images. The importance of our study comes from the fact that the segmentation of ROI from CT images is usually a difficult task. This difficulty is the gray’s level of which is similar to the other organ also the ROI are connected to the ribs, heart, kidneys, etc. Our proposed method is based on the anatomical information and mathematical morphology tools used in the image processing field. At first, we try to remove the surrounding and connected organs and tissues by applying morphological filters. This first step makes the extraction of interest regions easier. The second step consists of improving the quality of the image gradient. In this step, we propose a method for improving the image gradient to reduce these deficiencies by applying the spatial filters followed by the morphological filters. Thereafter we proceed to the segmentation of the liver, spleen. To validate the segmentation technique proposed, we have tested it on several images. Our segmentation approach is evaluated by comparing our results with the manual segmentation performed by an expert. The experimental results are described in the last part of this work.The system has been evaluated by computing the sensitivity and specificity between the semi-automatically segmented (liver and spleen) contour and the manually contour traced by radiological experts.

Keywords: CT images, liver and spleen segmentation, anisotropic diffusion filter, morphological filters, watershed algorithm

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1058 Determinants of Repeated Abortion among Women of Reproductive Age Attending Health Facilities in Northern Ethiopia: A Case-Control Study

Authors: Henok Yebyo Henok, Araya Abrha Araya, Alemayehu Bayray Alemayehu, Gelila Goba Gelila

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Background: Every year, an estimated 19–20 million unsafe abortions take place, almost all in developing countries, leading to 68,000 deaths and millions more injured many permanently. Many women throughout the world, experience more than one abortion in their lifetimes. Repeat abortion is an indicator of the larger problem of unintended pregnancy. This study aimed to identify determinants of repeat abortion in Tigray Region, Ethiopia. Methods: Unmatched case-control study was conducted in hospitals in Tigray Region, Northern Ethiopia, from November 2014 to June 2015. The sample included 105 cases and 204 controls, recruited from among women seeking abortion care at public hospitals. Clients having two or more abortions (“repeat abortion”) were taken as cases, and those who had a total of one abortion were taken as controls (“single abortion”). Cases were selected consecutive based on proportional to size allocation while systematic sampling was employed for controls. Data were analyzed using SPSS version 20.0. Binary and multiple variable logistic regression analyses were calculated with 95% CI. Results: Mean age of cases was 24 years (±6.85) and 22 years (±6.25) for controls. 79.0% of cases had their sexual debut in less than 18 years of age compared to 57% of controls. 42.2% of controls and 23.8% of cases cited rape as the reason for having an abortion. Study participants who did not understand their fertility cycle and when they were most likely to conceive after menstruation (adjusted odds ratio [AOR]=2.0, 95% confidence interval [CI]: 1.1-3.7), having a previous abortion using medication(AOR=3.3, CI: 1.83, 6.11), having multiple sexual partners in the preceding 12 months (AOR=4.4, CI: 2.39,8.45), perceiving that the abortion procedure is not painful (AOR=2.3, CI: 1.31,4.26), initiating sexual intercourse before the age of 18 years (AOR=2.7, CI: 1.49, 5.23) and disclosure to a third-party about terminating the pregnancy (AOR=2.1, CI: 1.2,3.83) were independent predictors of repeat abortion. Conclusion: This study identified several factors correlated with women having repeat abortions. It may be helpful for the Government of Ethiopia to encourage women to delay sexual debut and decrease their number of sexual partners, including by promoting discussion within families about sexuality, to decrease the occurrence of repeated abortion.

Keywords: abortion, Ethiopia, repeated abortion, single abortion

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1057 Impact of Pulsing and Trickle Flow on Catalytic Wet Air Oxidation of Phenolic Compounds in Waste Water at High Pressure

Authors: Safa'a M. Rasheed, Saba A. Gheni, Wadood T. Mohamed

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Phenolic compounds are the most carcinogenic pollutants in waste water in effluents of refineries and pulp industry. Catalytic wet air oxidation is an efficient industrial treatment process to oxidize phenolic compounds into unharmful organic compounds. Mode of flow of the fluid to be treated is a dominant factor in determining effectiveness of the catalytic process. The present study aims to obtain a mathematical model describing the conversion of phenolic compounds as a function of the process variables; mode of flow (trickling and pulsing), temperature, pressure, along with a high concentration of phenols and a platinum supported alumina catalyst. The model was validated with the results of experiments obtained in a fixed bed reactor. High pressure and temperature were employed at 8 bar and 140 °C. It has been found that conversion of phenols is highly influenced by mode of flow and the change is caused by changes occurred in hydrodynamic regime at the time of pulsing flow mode, thereby a temporal variation in wetting efficiency of platinum prevails; which in turn increases and/or decreases contact time with phenols in wastewater. The model obtained was validated with experimental results, and it is found that the model is a good agreement with the experimental results.

Keywords: wastewater, phenol, pulsing flow, wet oxidation, high pressure

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1056 Management of Third Stage Labour in a Rural Ugandan Hospital

Authors: Brid Dinnee, Jessica Taylor, Joseph Hartland, Michael Natarajan

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Background:The third stage of labour (TSL) can be complicated by Post-Partum Haemorrhage (PPH), which can have a significant impact on maternal mortality and morbidity. In Africa, 33.9% of maternal deaths are attributable to PPH1. In order to minimise this figure, current recommendations for the developing world are that all women have active management of the third stage of labour (AMTSL). The aim of this project was to examine TSL practice in a rural Ugandan Hospital, highlight any deviation from best practice and identify barriers to change in resource limited settings as part of a 4th year medical student External Student Selected Component field trip. Method: Five key elements from the current World Health Organisation (WHO) guidelines on AMTSL were used to develop an audit tool. All daytime vaginal deliveries over a two week period in July 2016 were audited. In addition to this, a retrospective comparison of PPH rates, between 2006 (when ubiquitous use of intramuscular oxytocin for management of TSL was introduced) and 2015 was performed. Results: Eight vaginal deliveries were observed; at all of which intramuscular oxytocin was administered and controlled cord traction used. Against WHO recommendation, all umbilical cords were clamped within one minute, and no infants received early skin-to-skin contact. In only one case was uterine massage performed after placental delivery. A retrospective comparison of data rates identified a 40% reduction in total number of PPHs from November 2006 to November 2015. Maternal deaths per delivery reduced from 2% to 0.5%. Discussion: Maternal mortality and PPH are still major issues in developing countries. Maternal mortality due to PPH can be reduced by good practices regarding TSL, but not all of these are used in low-resource settings. There is a notable difference in outcomes between the developed and developing world. At Kitovu Hospital, there has been a reduction in maternal mortality and number of PPHs following introduction of IM Oxytocin administration. In order to further improve these rates, staff education and further government funding is key.

Keywords: post-partum haemorrhage, PPH, third stage labour, Uganda

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1055 Impact Evaluation of Vaccination against Eight-Child-Killer Diseases on under-Five Children Mortality at Mbale District, Uganda

Authors: Lukman Abiodun Nafiu

Abstract:

This study examines the impact evaluation of vaccination against eight-child-killer diseases on under-five children mortality at Mbale District. It was driven by three specific objectives which are to determine the proportion of under-five children mortality due to the eight-child-killer diseases to the total under-five children mortality; establish the cause-effect relationship between the eight-child-killer diseases and under-five children mortality; as well as establish the dependence of under-five children mortality in the location at Mbale District. A community based cross-sectional and longitudinal (panel) study design involving both quantitative and qualitative (focus group discussion and in-depth interview) approaches was employed over a period of 36 months. Multi-stage cluster design involving Health Sub-District (HSD), Forms of Ownership (FOO) and Health Facilities Centres (HFC) as the first, second and third stages respectively was used. Data was collected regarding the eight-child-killer diseases namely: measles, pneumonia, pertussis (whooping cough), diphtheria, poliomyelitis (polio), tetanus, haemophilus influenza, rotavirus gastroenteritis and mortality regarding immunized and non-immunized children aged 0-59 months. We monitored the children over a period of 24 months. The study used a sample of 384 children out of all the registered children for each year at Mbale Referral Hospital and other Primary Health Care Centres (HCIV, HCIII and HCII) at Mbale District between 2015 and 2019. These children were followed from birth to their current state (living or dead). The data collected in this study was analysed using cross tabulation and the chi-square test. The study concluded that majority of mothers at Mbale district took their children for immunization and thus reducing the occurrence of under-five children mortality. Overall, 2.3%, 4.6%, 3.1%, 5.4%, 1.5%, 3.8%, 0.0% and 0.0% of under-five children had polio, tetanus, diphtheria, measles, pertussis, pneumonia, haemophilus influenzae and rotavirus gastroenteritis respectively across all the sub counties at Mbale district during the period considered. Also, different locations (sub counties) do not have significant influence on the occurrence of these eight-child-killer diseases among the under-five children at Mbale district. Therefore, the study recommended that government and agencies should continue to work together to implement measures of vaccination programs and increasing access to basic health care with a continuous improvement on the social interventions to progress child survival.

Keywords: Diseases, Mortality, Children, Vaccination

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1054 NextCovps: Design and Stress Analysis of Dome Composite Overwrapped Pressure Vessels using Geodesic Trajectory Approach

Authors: Ammar Maziz, Prateek Gupta, Thiago Vasconcellos Birro, Benoit Gely

Abstract:

Hydrogen as a sustainable fuel has the highest energy density per mass as compared to conventional non-renewable sources. As the world looks to move towards sustainability, especially in the sectors of aviation and automotive, it becomes important to address the issue of storage of hydrogen as compressed gas in high-pressure tanks. To improve the design for the efficient storage and transportation of Hydrogen, this paper presents the design and stress analysis of Dome Composite Overwrapped Pressure Vessels (COPVs) using the geodesic trajectory approach. The geodesic trajectory approach is used to optimize the dome design, resulting in a lightweight and efficient structure. Python scripting is employed to implement the mathematical modeling of the COPV, and after validating the model by comparison to the published paper, stress analysis is conducted using Abaqus commercial code. The results demonstrate the effectiveness of the geodesic trajectory approach in achieving a lightweight and structurally sound dome design, as well as the accuracy and reliability of the stress analysis using Abaqus commercial code. This study provides insights into the design and analysis of COPVs for aerospace applications, with the potential for further optimization and application in other industries.

Keywords: composite overwrapped pressure vessels, carbon fiber, geodesic trajectory approach, dome design, stress analysis, plugin python

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1053 A Study of Two Disease Models: With and Without Incubation Period

Authors: H. C. Chinwenyi, H. D. Ibrahim, J. O. Adekunle

Abstract:

The incubation period is defined as the time from infection with a microorganism to development of symptoms. In this research, two disease models: one with incubation period and another without incubation period were studied. The study involves the use of a  mathematical model with a single incubation period. The test for the existence and stability of the disease free and the endemic equilibrium states for both models were carried out. The fourth order Runge-Kutta method was used to solve both models numerically. Finally, a computer program in MATLAB was developed to run the numerical experiments. From the results, we are able to show that the endemic equilibrium state of the model with incubation period is locally asymptotically stable whereas the endemic equilibrium state of the model without incubation period is unstable under certain conditions on the given model parameters. It was also established that the disease free equilibrium states of the model with and without incubation period are locally asymptotically stable. Furthermore, results from numerical experiments using empirical data obtained from Nigeria Centre for Disease Control (NCDC) showed that the overall population of the infected people for the model with incubation period is higher than that without incubation period. We also established from the results obtained that as the transmission rate from susceptible to infected population increases, the peak values of the infected population for the model with incubation period decrease and are always less than those for the model without incubation period.

Keywords: asymptotic stability, Hartman-Grobman stability criterion, incubation period, Routh-Hurwitz criterion, Runge-Kutta method

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1052 Design Thinking Activities: A Tool in Overcoming Student Reticence

Authors: Marinel Dayawon

Abstract:

Student participation in classroom activities is vital in the teaching- learning the process as it develops self-confidence, social relationships and good academic performance of students. It is the teacher’s empathetic manner and creativity to create solutions that encourage teamwork and mutual support while dropping the academic competition within the class that hinder every shy student to walk with courage and talk with conviction because they consider their ideas, weak, as compared to the bright students. This study aimed to explore the different design thinking strategies that will change the mindset of shy students in classroom activities, maximizing their participation in all given tasks while sharing their views through ideation and providing them a wider world through compromise agreement within the members of the group, sensitivity to one’s idea, thus, arriving at a collective decision in the development of a prototype that indicates improvement in their classroom involvement. The study used the qualitative type of research. Triangulation is done through participant observation, focus group discussion and interview, documented through photos and videos. The respondents were the second- year Bachelor of Secondary Education students of the Institute of Teacher Education at Isabela State University- Cauayan City Campus. The result of the study revealed that reticent students when involved in game activities through a slap and tap method, writing their clustered ideas, using sticky notes is excited in sharing ideas as it doesn’t use oral communication. It is also observed after three weeks of using the design thinking strategies; shy students volunteer as secretary, rapporteur or group leader in the team- building activities as it represents the ideas of the heterogeneous group, removing the individual identity of the ideas. Superior students learned to listen to the ideas of the reticent students and involved them in the prototyping process of designing a remediation program for high school students showing reticence in the classroom, making their experience as a benchmark. The strategies made a 360- degrees transformation of the shy students, producing their journal log, in their journey to being open. Thus, faculty members are now adopting the design thinking approach.

Keywords: design thinking activities, qualitative, reticent students, Isabela, Philippines

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1051 Incident Management System: An Essential Tool for Oil Spill Response

Authors: Ali Heyder Alatas, D. Xin, L. Nai Ming

Abstract:

An oil spill emergency can vary in size and complexity, subject to factors such as volume and characteristics of spilled oil, incident location, impacted sensitivities and resources required. A major incident typically involves numerous stakeholders; these include the responsible party, response organisations, government authorities across multiple jurisdictions, local communities, and a spectrum of technical experts. An incident management team will encounter numerous challenges. Factors such as limited access to location, adverse weather, poor communication, and lack of pre-identified resources can impede a response; delays caused by an inefficient response can exacerbate impacts caused to the wider environment, socio-economic and cultural resources. It is essential that all parties work based on defined roles, responsibilities and authority, and ensure the availability of sufficient resources. To promote steadfast coordination and overcome the challenges highlighted, an Incident Management System (IMS) offers an essential tool for oil spill response. It provides clarity in command and control, improves communication and coordination, facilitates the cooperation between stakeholders, and integrates resources committed. Following the preceding discussion, a comprehensive review of existing literature serves to illustrate the application of IMS in oil spill response to overcome common challenges faced in a major-scaled incident. With a primary audience comprising practitioners in mind, this study will discuss key principles of incident management which enables an effective response, along with pitfalls and challenges, particularly, the tension between government and industry; case studies will be used to frame learning and issues consolidated from previous research, and provide the context to link practice with theory. It will also feature the industry approach to incident management which was further crystallized as part of a review by the Joint Industry Project (JIP) established in the wake of the Macondo well control incident. The authors posit that a common IMS which can be adopted across the industry not only enhances response capacity towards a major oil spill incident but is essential to the global preparedness effort.

Keywords: command and control, incident management system, oil spill response, response organisation

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1050 Correlations Between Electrical Resistivity and Some Properties of Clayey Soils

Authors: F. A. Hassona, M. M. Abu-Heleika, M. A. Hassan, A. E. Sidhom

Abstract:

Application of electrical measurements to evaluate engineering properties of soils has gained a wide, promising field of research in recent years. So, understanding of the relation between in-situ electrical resistivity of clay soil, and their mechanical and physical properties consider a promising field of research. This would assist in introducing a new technique for the determination of soil properties based on electrical resistivity. In this work soil physical and mechanical properties of clayey soil have been determined by experimental tests and correlated with the in-situ electrical resistivity. The research program was conducted through measuring fifteen vertical electrical sounding stations along with fifteen selected boreholes. These samples were analyzed and subjected to experimental tests such as physical tests namely bulk density, water content, specific gravity, and grain size distribution, and Attereberg limits tests. Mechanical test was also conducted such as direct shear test. The electrical resistivity data were interpreted and correlated with each one of the measured experimental parameters. Based on this study mathematical relations were extracted and discussed. These results exhibit an excellent match with the results reported in the literature. This study demonstrates the utility of the developed methodology for determining the mechanical properties of soils easily and rapidly depending on their electrical resistivity measurements.

Keywords: electrical resistivity, clayey soil, physical properties, shear properties

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1049 Mathematical Modeling of Eggplant Slices Drying Using Microwave-Oven

Authors: M.H. Keshek, M.N. Omar, A.H. Amer

Abstract:

Eggplant (Solanum melongena L.) is considered one of the most important crops in summer season, and it is grown in most cultivated area in Egypt. Eggplant has a very limited shelf life for freshness and physiological changes occur after harvest. Nowadays, microwave drying offers an alternative way to drying agricultural products. microwave drying is not only faster but also requiring less energy consumption than conventional drying. The main objective of this research was to evaluate using the microwave oven in Eggplant drying, to determine the optimum drying time of higher drying efficiency and lower energy consumption. The eggplants slices, having a thickness of about 5, 10, 15, and 20 mm, with diameter 50±2 mm was dried using microwave oven (KOR-9G2B) using three different levels were 450, 630, and 810 Watt (50%, 70%, and 90% of 900 Watt). The results show that, the initial moisture content of the eggplant slices was around 93 % wet basis (13.28 g water/g dry matter). The results indicated that, the moisture transfer within the sample was more rapidly during higher microwave power heating (810 watt) and lower thickness (5 mm) of the eggplant slices. In addition, the results show that, the drying efficiency increases by increasing slices thickness at power levels 450, 630 and 810 Watt. The higher drying efficiency was 83.13% occurred when drying the eggplant slices 20 mm thickness in microwave oven at power 630 Watt. the higher total energy consumption per dry kilogram was 1.275 (kWh/ dry kg) occurred at used microwave 810 Watt for drying eggplant slices 5 mm thickness, and the lower total energy consumption per dry kilogram was 0.55 (kWh/ dry kg) occurred at used microwave 810 Watt for drying eggplant slices 20 mm thickness.

Keywords: microwave drying, eggplant, drying rate, drying efficiency, energy consumption

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1048 Ectopic Mediastinal Parathyroid Adenoma: A Case Report with Diagnostic and Management Challenges

Authors: Augustina Konadu Larbi-Ampofo, Ekemini Umoinwek

Abstract:

Background: Hypercalcaemia is a common electrolyte imbalance that increases mortality if poorly controlled. Primary hyperparathyroidism often presents like this with a prevalence of 0.1-0.3%. Management due to an ectopic parathyroid adenoma in the mediastinum is challenging, especially in a patient with a pacemaker. Case Presentation: A 79-year-old woman with a history of a previous cardiac arrest, permanent pacemaker, ischaemic heart disease, bilateral renal calculi, rectal polyps, liver cirrhosis, and a family history of hyperthyroidism presented to the emergency department with acute back pain. Management and Outcome: The patient was diagnosed with primary hyperparathyroidism due to her elevated corrected calcium and parathyroid hormone levels. Parathyroid investigations consisting of an NM MIBI scan, SPECT-CT, 4D parathyroid scan, and an ultrasound scan of the neck and thorax confirmed an ectopic parathyroid adenoma in the mediastinum at the level of the aortic arch, along with benign thyroid nodules. The location of the adenoma warranted a thoracoscopic surgical approach; however, the presence of her pacemaker and other cardiovascular conditions predisposed her to a potentially poorer post-operative outcome. Discussion: Mediastinal ectopic parathyroid adenomas are rare and difficult to diagnose and treat, often needing a multimodal imaging approach for accurate localisation. Surgery is a definitive treatment; however, in this patient, long-term medical treatment with cinacalcet was the only next suitable treatment option. The difficulty with this is that cinacalcet tackles the biochemical markers of the disease entity and not the disease itself, leaving room for what happens next if there is refractory/uncontrolled hypercalcaemia in this patient with a pacemaker. Moreover, the coexistence of her multiple conditions raises the suspicion of an underlying multisystemic or multiple endocrine disorder, with multiple endocrine neoplasia coming to mind, necessitating further genetic or autoimmune investigations. Conclusion: Mediastinal ectopic parathyroid adenomas are rare, with diagnostic and management challenges.

Keywords: mediastinal ectopic parathyroid adenoma, hyperparathyroidism, SPECT/CT, nuclear medicine, multimodal imaging

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1047 The Effect of Damper Attachment on Tennis Racket Vibration: A Simulation Study

Authors: Kuangyou B. Cheng

Abstract:

Tennis is among the most popular sports worldwide. During ball-racket impact, substantial vibration transmitted to the hand/arm may be the cause of “tennis elbow”. Although it is common for athletes to attach a “vibration damper” to the spring-bed, the effect remains unclear. To avoid subjective factors and errors in data recording, the effect of damper attachment on racket handle end vibration was investigated with computer simulation. The tennis racket was modeled as a beam with free-free ends (similar to loosely holding the racket). Finite difference method with 40 segments was used to simulate ball-racket impact response. The effect of attaching a damper was modeled as having a segment with increased mass. It was found that the damper has the largest effect when installed at the spring-bed center. However, this is not a practical location due to interference with ball-racket impact. Vibration amplitude changed very slightly when the damper was near the top or bottom of the spring-bed. The damper works only slightly better at the bottom than at the top of the spring-bed. In addition, heavier dampers work better than lighter ones. These simulation results were comparable with experimental recordings in which the selection of damper locations was restricted by ball impact locations. It was concluded that mathematical model simulations were able to objectively investigate the effect of damper attachment on racket vibration. In addition, with very slight difference in grip end vibration amplitude when the damper was attached at the top or bottom of the spring-bed, whether the effect can really be felt by athletes is questionable.

Keywords: finite difference, impact, modeling, vibration amplitude

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1046 Nonlinear Triad Interactions in Magnetohydrodynamic Plasma Turbulence

Authors: Yasser Rammah, Wolf-Christian Mueller

Abstract:

Nonlinear triad interactions in incompressible three-dimensional magnetohydrodynamic (3D-MHD) turbulence are studied by analyzing data from high-resolution direct numerical simulations of decaying isotropic (5123 grid points) and forced anisotropic (10242 x256 grid points) turbulence. An accurate numerical approach toward analyzing nonlinear turbulent energy transfer function and triad interactions is presented. It involves the direct numerical examination of every wavenumber triad that is associated with the nonlinear terms in the differential equations of MHD in the inertial range of turbulence. The technique allows us to compute the spectral energy transfer and energy fluxes, as well as the spectral locality property of energy transfer function. To this end, the geometrical shape of each underlying wavenumber triad that contributes to the statistical transfer density function is examined to infer the locality of the energy transfer. Results show that the total energy transfer is local via nonlocal triad interactions in decaying macroscopically isotropic MHD turbulence. In anisotropic MHD, turbulence subject to a strong mean magnetic field the nonlinear transfer is generally weaker and exhibits a moderate increase of nonlocality in both perpendicular and parallel directions compared to the isotropic case. These results support the recent mathematical findings, which also claim the locality of nonlinear energy transfer in MHD turbulence.

Keywords: magnetohydrodynamic (MHD) turbulence, transfer density function, locality function, direct numerical simulation (DNS)

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