Search results for: Business Performance
10469 Investigate and Control Thermal Spectra in Nanostructures and 2D Van der Waals Materials
Authors: Joon Sang Kang, Ming Ke, Yongjie Hu
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Controlling heat transfer and thermal properties of materials is important to many fields such as energy efficiency and thermal management of integrated circuits. Significant progress over the past decade has been made to improve material performance through structuring at the nanoscale, however a clear relationship between structure dimensions, interfaces, and thermal properties remains to be established. The main challenge comes from the unknown intrinsic spectral contribution from different phonons. Here, we describe our current progress on quantifying and controlling thermal spectra based on our recently developed technical approach using ultrafast optical spectroscopy. Our work brings further the promise of rational material design to achieve high performance through a synergistic experimental-modeling approach. This approach can be broadly applicable to a wide range of materials and energy systems. In particular, we demonstrate in-situ characterization and tunable thermal properties of 2D van der waals materials through ionic intercalations. The significant impacts of this research in improving the efficiency of thermal energy conversion and management will also be illustrated.Keywords: energy, mean free path, nanoscale heat transfer, nanostructure, phonons, TDTR, thermoelectrics, 2D materials
Procedia PDF Downloads 28810468 Evaluating the Effect of Spatial Qualities, Openness and Complexity, on Human Cognitive Performance within Virtual Reality
Authors: Pierre F. Gerard, Frederic F. Leymarie, William Latham
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Architects have developed a series of objective evaluations, using spatial analysis tools such as Isovist, that show how certain spatial qualities are beneficial to specific human activities hosted in the built environments. In return, they can build more adapted environments by tuning those spatial qualities in their design. In parallel, virtual reality technologies have been developed by engineers with the dream of creating a system that immerses users in a new form of spatial experiences. They already have demonstrated a useful range of benefits not only in simulating critical events to assist people in acquiring new skills, but also to enhance memory retention, to name just a few. This paper investigates the effects of two spatial qualities, openness, and complexity, on cognitive performance within immersive virtual environments. Isovist measure is used to design a series of room settings with different levels of each spatial qualities. In an empirical study, each room was then used by every participant to solve a navigational puzzle game and give a rating of their spatial experience. They were then asked to fill in a questionnaire before solving the visual-spatial memory quiz, which addressed how well they remembered the different rooms. Findings suggest that those spatial qualities have an effect on some of the measures, including navigation performance and memory retention. In particular, there is an order effect for the navigation puzzle game. Participants tended to spend a longer time in the complex room settings. Moreover, there is an interaction effect while with more open settings, participants tended to perform better when in a simple setting; however, with more closed settings, participants tended to perform better in a more complex setting. For the visual-spatial memory quiz, participants performed significantly better within the more open rooms. We believe this is a first step in using virtual environments to enhance participant cognitive performances through better use of specific spatial qualities.Keywords: architecture, navigation, spatial cognition, virtual reality
Procedia PDF Downloads 13010467 Effect of Acceptance and Commitment Therapy in Cognitive Function among Breast Cancer Patients in Eastern Country
Authors: Arunima Datta, Prathama Guha Chaudhuri, Ashis Mukhopadhyay
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Background: Acceptance and commitment therapy (ACT) is one of the newer forms (third wave) therapy. This therapy helps a cancer patient to increase acceptance level about their disease as well as their present situation. Breast cancer patients are known to suffer from depression and mild cognitive impairment; both affect their quality of life. Objectives:The present study had assessed effect of structured ACT intervention on cognitive function and acceptance level among breast cancer patients who were undergoing chemotherapy. Method: Data was collected from 123 breast cancer patients those who were undergoing chemotherapy were willing to undergo psychological treatment, with no history of past psychiatric illness. Their baseline of cognitive function and acceptance levels were assessed using validated tools. The effect of sociodemographic factors and clinical factors on cognitive function was determined at baseline.The participants were randomly divided into two groups: experimental (ACT, 4 sessions over 2 months) and control group. Cognitive function and acceptance level were measured during post intervention on 2months follow-up. Appropriate statistical analyses were performed to determine the effect on cognitive function and acceptance level in two groups. Result: At baseline, the factors that significantly influenced slower speed of task performance were ER PR HER2 status; number of chemo cycle, treatment type (Adjuvant and neo-adjuvant) was related with that. Sociodemographic characteristics did not show any significant difference between slow and fast performance. Per and post intervention analysis showed that ACT intervention resulted in significant difference both in terms of speed of cognitive performance and acceptance level. Conclusion: ACT is an effective therapeutic option for treating mild cognitive impairment and improve acceptance level among breast cancer patients undergoing chemotherapy.Keywords: acceptance and commitment therapy, breast cancer, quality of life, cognitive function
Procedia PDF Downloads 30510466 Scalable UI Test Automation for Large-scale Web Applications
Authors: Kuniaki Kudo, Raviraj Solanki, Kaushal Patel, Yash Virani
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This research mainly concerns optimizing UI test automation for large-scale web applications. The test target application is the HHAexchange homecare management WEB application that seamlessly connects providers, state Medicaid programs, managed care organizations (MCOs), and caregivers through one platform with large-scale functionalities. This study focuses on user interface automation testing for the WEB application. The quality assurance team must execute many manual users interface test cases in the development process to confirm no regression bugs. The team automated 346 test cases; the UI automation test execution time was over 17 hours. The business requirement was reducing the execution time to release high-quality products quickly, and the quality assurance automation team modernized the test automation framework to optimize the execution time. The base of the WEB UI automation test environment is Selenium, and the test code is written in Python. Adopting a compilation language to write test code leads to an inefficient flow when introducing scalability into a traditional test automation environment. In order to efficiently introduce scalability into Test Automation, a scripting language was adopted. The scalability implementation is mainly implemented with AWS's serverless technology, an elastic container service. The definition of scalability here is the ability to automatically set up computers to test automation and increase or decrease the number of computers running those tests. This means the scalable mechanism can help test cases run parallelly. Then test execution time is dramatically decreased. Also, introducing scalable test automation is for more than just reducing test execution time. There is a possibility that some challenging bugs are detected by introducing scalable test automation, such as race conditions, Etc. since test cases can be executed at same timing. If API and Unit tests are implemented, the test strategies can be adopted more efficiently for this scalability testing. However, in WEB applications, as a practical matter, API and Unit testing cannot cover 100% functional testing since they do not reach front-end codes. This study applied a scalable UI automation testing strategy to the large-scale homecare management system. It confirmed the optimization of the test case execution time and the detection of a challenging bug. This study first describes the detailed architecture of the scalable test automation environment, then describes the actual performance reduction time and an example of challenging issue detection.Keywords: aws, elastic container service, scalability, serverless, ui automation test
Procedia PDF Downloads 10610465 A Comprehensive Study of a Hybrid System Integrated Solid Oxide Fuel cell, Gas Turbine, Organic Rankine Cycle with Compressed air Energy Storage
Authors: Taiheng Zhang, Hongbin Zhao
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Compressed air energy storage become increasingly vital for solving intermittency problem of some renewable energies. In this study, a new hybrid system on a combination of compressed air energy storage (CAES), solid oxide fuel cell (SOFC), gas turbine (GT), and organic Rankine cycle (ORC) is proposed. In the new system, excess electricity during off-peak time is utilized to compress air. Then, the compressed air is stored in compressed air storage tank. During peak time, the compressed air enters the cathode of SOFC directly instead of combustion chamber of traditional CAES. There is no air compressor consumption of SOFC-GT in peak demand, so SOFC- GT can generate power with high-efficiency. In addition, the waste heat of exhaust from GT is recovered by applying an ORC. Three different organic working fluid (R123, R601, R601a) of ORC are chosen to evaluate system performance. Based on Aspen plus and Engineering Equation Solver (EES) software, energy and exergoeconomic analysis are used to access the viability of the combined system. Besides, the effect of two parameters (fuel flow and ORC turbine inlet pressure) on energy efficiency is studied. The effect of low-price electricity at off-peak hours on thermodynamic criteria (total unit exergy cost of products and total cost rate) is also investigated. Furthermore, for three different organic working fluids, the results of round-trip efficiency, exergy efficiency, and exergoeconomic factors are calculated and compared. Based on thermodynamic performance and exergoeconomic performance of different organic working fluids, the best suitable working fluid will be chosen. In conclusion, this study can provide important guidance for system efficiency improvement and viability.Keywords: CAES, SOFC, ORC, energy and exergoeconomic analysis, organic working fluids
Procedia PDF Downloads 12310464 Examining the Influence of Organisational Culture on Middle Leadership in Primary Schools in Saudi Arabia and United Kingdom
Authors: Saeed Musaid Alzahrani
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Shared values, beliefs, norms and assumptions within the organisation can affect personal and team effectiveness. Organisational culture can also affect the performance of organisational members. The nature of middle leadership in a primary school is largely influenced by organizational culture. The effectiveness of middle leadership in primary schools and their performance is strongly determined by the circumstances in which they work and can be political or institutional. This study aims to examine the influence of organisational culture and government policy on the performance and effectiveness of middle managers, using the English and Saudi education systems as case studies. To examine how education policy conditions educational discourse, and answer the research questions, there is a need to collect qualitative data on middle manager’s perceptions and experiences in the English and Saudi Arabian contexts. The study involved a qualitative and interpretative approach. In-depth interviews with 6 middle managers and school supervisors in 3 English primary schools and 6 middle managers in 3 Saudi Arabian primary schools were conducted to answer the research questions. The study also included ethnographic tools such as observations of a sample of three primary schools in both England and Saudi Arabia where the researcher observed middle managers’ interactions with their peers. The sample of three enabled the study to identify trends and make comparisons between leadership approaches in both systems based on observations without the bias of prescriptions. The use of ethnographic tools not only makes the study empirical but also increases the reliability and validity of the findings by reducing prescriptive bias. The observations will be triangulated with the results of the interviews to draw comparisons and conclusions on whether middle managers act as leaders or as followers in their respective political contexts.Keywords: education management, government education policies, middle managers, organisational culture
Procedia PDF Downloads 24010463 Metamorphic Computer Virus Classification Using Hidden Markov Model
Authors: Babak Bashari Rad
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A metamorphic computer virus uses different code transformation techniques to mutate its body in duplicated instances. Characteristics and function of new instances are mostly similar to their parents, but they cannot be easily detected by the majority of antivirus in market, as they depend on string signature-based detection techniques. The purpose of this research is to propose a Hidden Markov Model for classification of metamorphic viruses in executable files. In the proposed solution, portable executable files are inspected to extract the instructions opcodes needed for the examination of code. A Hidden Markov Model trained on portable executable files is employed to classify the metamorphic viruses of the same family. The proposed model is able to generate and recognize common statistical features of mutated code. The model has been evaluated by examining the model on a test data set. The performance of the model has been practically tested and evaluated based on False Positive Rate, Detection Rate and Overall Accuracy. The result showed an acceptable performance with high average of 99.7% Detection Rate.Keywords: malware classification, computer virus classification, metamorphic virus, metamorphic malware, Hidden Markov Model
Procedia PDF Downloads 31510462 Numerical Studies on the Performance of the Finned-Tube Heat Exchanger
Authors: S. P. Praveen Kumar, Bong-Su Sin, Kwon-Hee Lee
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Finned-tube heat exchangers are predominantly used in space conditioning systems, as well as other applications requiring heat exchange between two fluids. The design of finned-tube heat exchangers requires the selection of over a dozen design parameters by the designer such as tube pitch, tube diameter, tube thickness, etc. Finned-tube heat exchangers are common devices; however, their performance characteristics are complicated. In this paper, numerical studies have been carried out to analyze the performances of finned tube heat exchanger (without fins considered for experimental purpose) by predicting the characteristics of temperature difference and pressure drop. In this study, a design considering 5 design variables, maximizing the temperature difference and minimizing the pressure drop was suggested by applying DOE. In this process, L18 orthogonal array was adopted. Parametric analytical studies have been carried out using Analysis of Variance (ANOVA) to determine the relative importance of each variable with respect to the temperature difference and the pressure drop. Following the results, the final design was suggested by predicting the optimum design therefore confirming the optimized condition.Keywords: heat exchanger, fluid analysis, heat transfer, design of experiment, analysis of variance
Procedia PDF Downloads 44610461 Optimization of SWL Algorithms Using Alternative Adder Module in FPGA
Authors: Tayab D. Memon, Shahji Farooque, Marvi Deshi, Imtiaz Hussain Kalwar, B. S. Chowdhry
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Recently single-bit ternary FIR-like filter (SBTFF) hardware synthesize in FPGA is reported and compared with multi-bit FIR filter on similar spectral characteristics. Results shows that SBTFF dominates upon multi-bit filter overall. In this paper, an optimized adder module for ternary quantized sigma-delta modulated signal is presented. The adder is simulated using ModelSim for functional verification the area-performance of the proposed adder were obtained through synthesis in Xilinx and compared to conventional adder trees. The synthesis results show that the proposed adder tree achieves higher clock rates and lower chip area at higher inputs to the adder block; whereas conventional adder tree achieves better performance and lower chip area at lower number of inputs to the same adder block. These results enhance the usefulness of existing short word length DSP algorithms for fast and efficient mobile communication.Keywords: short word length (SWL), DSP algorithms, FPGA, SBTFF, VHDL
Procedia PDF Downloads 34510460 Evaluation and Selection of Contractors in Construction Projects with a View Supply Chain Management and Utilization of Promthee
Authors: Sara Najiazarpour, Mahsa Najiazarpour
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There are many problems in contracting projects and their performance. At each project stage and due to different reasons, these problems affect cost, time and overall project quality. Hence, in order to increase the efficiency and performance in all levels of the chain and with supply chain management approach, there will be a coordination from the beginning of a project (contractor selection) to the end of project (handover of project). Contractor selection is the foremost part of construction projects which in this multi-criteria decision-making, the best contractor is determined by expert judgment, different variables and their priorities. In this paper for selecting the best contractor, numerous criteria were collected by asking from adept experts and then among them, 16 criteria with highest frequency were considered for questionnaire. This questionnaire was distributed between experts. Cronbach's alpha coefficient was obtained as 72%. Then based on Borda's function 12 important criteria was selected which was categorized in four main criteria and related sub-criteria as follow: Environmental factors and physical equipment: procurement and materials (supplier), company's machines, contractor’s proposed cost estimate - financial capacity: bank turnover and company's assets, the income of tax declaration in last year, Ability to compensate for losses or delays - past performance- records and technical expertise: experts and key personnel, the past technical backgrounds and experiences, employer satisfaction of previous contracts, the number of similar projects was done - standards: rank and field of expertise which company is qualified for and its validity, availability and number of permitted projects done. Then with PROMTHEE method, the criteria were normalized and monitored, finally the best alternative was selected. In this research, qualitative criteria of each company is became a quantitative criteria. Finally, information of some companies was evaluated and the best contractor was selected based on all criteria and their priorities.Keywords: contractor evaluation and selection, project development, supply chain management, PROMTHEE method
Procedia PDF Downloads 7210459 Development of Structural Deterioration Models for Flexible Pavement Using Traffic Speed Deflectometer Data
Authors: Sittampalam Manoharan, Gary Chai, Sanaul Chowdhury, Andrew Golding
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The primary objective of this paper is to present a simplified approach to develop the structural deterioration model using traffic speed deflectometer data for flexible pavements. Maintaining assets to meet functional performance is not economical or sustainable in the long terms, and it would end up needing much more investments for road agencies and extra costs for road users. Performance models have to be included for structural and functional predicting capabilities, in order to assess the needs, and the time frame of those needs. As such structural modelling plays a vital role in the prediction of pavement performance. A structural condition is important for the prediction of remaining life and overall health of a road network and also major influence on the valuation of road pavement. Therefore, the structural deterioration model is a critical input into pavement management system for predicting pavement rehabilitation needs accurately. The Traffic Speed Deflectometer (TSD) is a vehicle-mounted Doppler laser system that is capable of continuously measuring the structural bearing capacity of a pavement whilst moving at traffic speeds. The device’s high accuracy, high speed, and continuous deflection profiles are useful for network-level applications such as predicting road rehabilitations needs and remaining structural service life. The methodology adopted in this model by utilizing time series TSD maximum deflection (D0) data in conjunction with rutting, rutting progression, pavement age, subgrade strength and equivalent standard axle (ESA) data. Then, regression analyses were undertaken to establish a correlation equation of structural deterioration as a function of rutting, pavement age, seal age and equivalent standard axle (ESA). This study developed a simple structural deterioration model which will enable to incorporate available TSD structural data in pavement management system for developing network-level pavement investment strategies. Therefore, the available funding can be used effectively to minimize the whole –of- life cost of the road asset and also improve pavement performance. This study will contribute to narrowing the knowledge gap in structural data usage in network level investment analysis and provide a simple methodology to use structural data effectively in investment decision-making process for road agencies to manage aging road assets.Keywords: adjusted structural number (SNP), maximum deflection (D0), equant standard axle (ESA), traffic speed deflectometer (TSD)
Procedia PDF Downloads 15110458 Electrochemical Performance of Femtosecond Laser Structured Commercial Solid Oxide Fuel Cells Electrolyte
Authors: Mohamed A. Baba, Gazy Rodowan, Brigita Abakevičienė, Sigitas Tamulevičius, Bartlomiej Lemieszek, Sebastian Molin, Tomas Tamulevičius
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Solid oxide fuel cells (SOFC) efficiently convert hydrogen to energy without producing any disturbances or contaminants. The core of the cell is electrolyte. For improving the performance of electrolyte-supported cells, it is desirable to extend the available exchange surface area by micro-structuring of the electrolyte with laser-based micromachining. This study investigated the electrochemical performance of cells micro machined using a femtosecond laser. Commercial ceramic SOFC (Elcogen, AS) with a total thickness of 400 μm was structured by 1030 nm wavelength Yb: KGW fs-laser Pharos (Light Conversion) using 100 kHz repetition frequency and 290 fs pulse length light by scanning with the galvanometer scanner (ScanLab) and focused with a f-Theta telecentric lens (SillOptics). The sample height was positioned using a motorized z-stage. The microstructures were formed using a laser spiral trepanning in Ni/YSZ anode supported membrane at the central part of the ceramic piece of 5.5 mm diameter at active area of the cell. All surface was drilled with 275 µm diameter holes spaced by 275 µm. The machining processes were carried out under ambient conditions. The microstructural effects of the femtosecond laser treatment on the electrolyte surface were investigated prior to the electrochemical characterisation using a scanning electron microscope (SEM) Quanta 200 FEG (FEI). The Novo control Alpha-A was used for electrochemical impedance spectroscopy on a symmetrical cell configuration with an excitation amplitude of 25 mV and a frequency range of 1 MHz to 0.1 Hz. The fuel cell characterization of the cell was examined on open flanges test setup by Fiaxell. Using nickel mesh on the anode side and au mesh on the cathode side, the cell was electrically linked. The cell was placed in a Kittec furnace with a Process IDentifier temperature controller. The wires were connected to a Solartron 1260/1287 frequency analyzer for the impedance and current-voltage characterization. In order to determine the impact of the anode's microstructure on the performance of the commercial cells, the acquired results were compared to cells with unstructured anode. Geometrical studies verified that the depth of the -holes increased linearly according to laser energy and scanning times. On the other hand, it reduced as the scanning speed increased. The electrochemical analysis demonstrates that the open circuit voltage OCV values of the two cells are equal. Further, the modified cell's initial slope reduces to 0.209 from 0.253 of the unmodified cell, revealing that the surface modification considerably decreases energy loss. Plus, the maximum power density for the cell with the microstructure and the reference cell respectively, are 1.45 and 1.16 Wcm⁻².Keywords: electrochemical performance, electrolyte-supported cells, laser micro-structuring, solid oxide fuel cells
Procedia PDF Downloads 6810457 Comparative Quantitative Study on Learning Outcomes of Major Study Groups of an Information and Communication Technology Bachelor Educational Program
Authors: Kari Björn, Mikael Soini
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Higher Education system reforms, especially Finnish system of Universities of Applied Sciences in 2014 are discussed. The new steering model is based on major legislative changes, output-oriented funding and open information. The governmental steering reform, especially the financial model and the resulting institutional level responses, such as a curriculum reforms are discussed, focusing especially in engineering programs. The paper is motivated by management need to establish objective steering-related performance indicators and to apply them consistently across all educational programs. The close relationship to governmental steering and funding model imply that internally derived indicators can be directly applied. Metropolia University of Applied Sciences (MUAS) as a case institution is briefly introduced, focusing on engineering education in Information and Communications Technology (ICT), and its related programs. The reform forced consolidation of previously separate smaller programs into fewer units of student application. New curriculum ICT students have a common first year before they apply for a Major. A framework of parallel and longitudinal comparisons is introduced and used across Majors in two campuses. The new externally introduced performance criteria are applied internally on ICT Majors using data ex-ante and ex-post of program merger. A comparative performance of the Majors after completion of joint first year is established, focusing on previously omitted Majors for completeness of analysis. Some new research questions resulting from transfer of Majors between campuses and quota setting are discussed. Practical orientation identifies best practices to share or targets needing most attention for improvement. This level of analysis is directly applicable at student group and teaching team level, where corrective actions are possible, when identified. The analysis is quantitative and the nature of the corrective actions are not discussed. Causal relationships and factor analysis are omitted, because campuses, their staff and various pedagogical implementation details contain still too many undetermined factors for our limited data. Such qualitative analysis is left for further research. Further study must, however, be guided by the relevance of the observations.Keywords: engineering education, integrated curriculum, learning outcomes, performance measurement
Procedia PDF Downloads 24110456 A Parametric Study on Aerodynamic Performance of Tyre Using CFD
Authors: Sowntharya L.
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Aerodynamics is the most important factor when it comes to resistive forces such as lift, drag and side forces acting on the vehicle. In passenger vehicles, reducing the drag will not only unlock the door for higher achievable speed but will also reduce the fuel consumption of the vehicle. Generally, tyre contributes significantly to the overall aerodynamics of the vehicle. Hence, understanding the air-flow behaviour around the tyre is vital to optimize the aerodynamic performance in the early stage of design process. Nowadays, aerodynamic simulation employing Computational Fluid Dynamics (CFD) is gaining more importance as it reduces the number of physical wind-tunnel experiments during vehicle development process. This research develops a methodology to predict aerodynamic drag of a standalone tyre using Numerical CFD Solver and to validate the same using a wind tunnel experiment. A parametric study was carried out on different tread pattern tyres such as slick, circumferential groove & patterned tyre in stationary and rotating boundary conditions. In order to represent wheel rotation contact with the ground, moving reference frame (MRF) approach was used in this study. Aerodynamic parameters such as drag lift & air flow behaviour around the tire were simulated and compared with experimental results.Keywords: aerodynamics, CFD, drag, MRF, wind-tunnel
Procedia PDF Downloads 19410455 Heat Transfer Enhancement Using Aluminium Oxide Nanofluid: Effect of the Base Fluid
Authors: M. Amoura, M. Benmoussa, N. Zeraibi
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The flow and heat transfer is an important phenomenon in engineering systems due to its wide application in electronic cooling, heat exchangers, double pane windows etc.. The enhancement of heat transfer in these systems is an essential topic from an energy saving perspective. Lower heat transfer performance when conventional fluids, such as water, engine oil and ethylene glycol are used hinders improvements in performance and causes a consequent reduction in the size of such systems. The use of solid particles as an additive suspended into the base fluid is a technique for heat transfer enhancement. Therefore, the heat transfer enhancement in a horizontal circular tube that is maintained at a constant temperature under laminar regime has been investigated numerically. A computational code applied to the problem by use of the finite volume method was developed. Nanofluid was made by dispersion of Al2O3 nanoparticles in pure water and ethylene glycol. Results illustrate that the suspended nanoparticles increase the heat transfer with an increase in the nanoparticles volume fraction and for a considered range of Reynolds numbers. On the other hand, the heat transfer is very sensitive to the base fluid.Keywords: Al2O3 nanoparticles, circular tube, heat transfert enhancement, numerical simulation
Procedia PDF Downloads 32210454 Internal Power Recovery in Cryogenic Cooling Plants, Part II: Compressor Development
Authors: Ambra Giovannelli, Erika Maria Archilei
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The electrical power consumption related to refrigeration systems is evaluated to be in the order of 15% of the total electricity consumption worldwide. For this reason, in the last years several energy saving techniques have been suggested to reduce the power demand of refrigeration and air conditioning plants. The research work deals with the development of an innovative internal power recovery system for industrial cryogenic cooling plants. Such system is based on a Compressor-Expander Group (CEG). Both the expander and the compressor have been designed starting from automotive turbocharging components, strongly modified to take refrigerant fluid properties and specific system requirements into consideration. A preliminary choice of the machines (radial compressors and expanders) among existing components available on the market was realised according to the rules of the similarity theory. Once the expander was selected, it was strongly modified and performance verified by means of steady-state 3D CFD simulations. This paper focuses the attention on the development of the second CEG main component: the compressor. Once the preliminary selection has been done, the compressor geometry has been modified to take the new boundary conditions into account. In particular, the impeller has been machined to address the required total enthalpy increase. Such evaluation has been carried out by means of a simplified 1D model. Moreover, a vaneless diffuser has been added, modifying the shape of casing rear and front disks. To verify the performance of the modified compressor geometry and suggest improvements, a numerical fluid dynamic model has been set up and the commercial Ansys-CFX software has been used to perform steady-state 3D simulations. In this work, all the numerical results will be shown, highlighting critical aspects and suggesting further developments to increase compressor performance and flexibility.Keywords: vapour compression systems, energy saving, refrigeration plant, organic fluids, centrifugal compressor
Procedia PDF Downloads 21710453 The Effects of Arginine, Glutamine and Threonine Supplementation in the Starting Phase on Subsequent Performance of Male Broile
Authors: Jalal Fazli Amiri, Mohammad Hossein Shahir, Mohammad Hossein Nemati, Afshin Heidarinia
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The current study was performed to investigate the effects of arginine, threonine, and glutamine supplementation in excess of requirements in the starter period (17 days) on performance, intestinal morphology, and immune response of broilers. Four hundred and sixteen male day-old chicks were assigned in a 2×2×2 factorial arrangement to a completely randomized design with four replicates (13 birds per replicate ). Treatments were: a control group that received the basal diet, basal diet plus 1% glutamine, basal diet plus 0.2% threonine, basal diet plus 0.75 % arginine, and combination of these three amino acids (glutamine+arginine, glutamine+threonine, arginine+threonine and arginine+ glutamine+threonine). The effect of glutamine supplementation on feed intake was significant in week 4 (p < 0.05), week 6 (p < 0.001), and total feed intake (p < 0.05) and caused declined feed intake. No significant differences of glutamine addition were observed on intestinal morphology (villi height, crypt depth, villi height to crypt depth ratio, villi width). Threonine supplementation caused increased weight gain in week 2 (p < 0.001) and 3 and a decrease of total feed intake (p < 0.05). Duodenum and jejunum villi height, crypt depth, villi height to crypt depth ratio, villi width were not affected. The effect of arginine supplementation was the increase of breast percentage (p < 0.05) and a decrease of jejunum villi high (p < 0.05) and Jejunum crypt depth (p < 0.05). Supplementation of arginine, threonine, and glutamine had no significant effects on blood titer of antibodies against Newcastle disease, infectious bronchitis, avian influenza. Overall, it seems that the supplementation of arginine, threonine, and glutamine in excess of requirements in the starter period had no effect on performance in subsequent periods and intestinal morphology.Keywords: intestinal morphology, immunity, broiler chickens, glutamine, arginine, threonine
Procedia PDF Downloads 13710452 Hydraulic Performance of Urban Drainage System Using SWMM: A Case Study of Siti Khadijah Retention Pond in Palembang City
Authors: Muhammad B. Al Amin, Nyimas S. Rika, Dwi F. Yanto, Marcelina
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Siti Khadijah retention pond is located beside of Siti Khadijah Islamic Hospital on Demang Lebar Daun Street in Palembang City. This retention pond is functioned as storage for runoff from drainage channels in the surrounding area before entering Sekanak River, which is one of Musi River tributaries. However, in recent years, the developments in the surrounding area into paved area trigger to increase runoff discharge that causes the pond can no longer store it adequately. This study aimed to investigate the hydraulic performance of drainage system in the area around Siti Khadijah retention pond. A SWMM model was used to simulate runoff discharge into the pond and out from the pond, so the water level fluctuation within the pond and its capacity could be determined. Besides that, the water depth within drainage channels was simulated as well. The results showed that capacity of retention pond and some drainage channels already inadequate, so the area around it potentially to be flooded. Thus, it is necessary to increase the capacity of the retention pond and drainage channels.Keywords: flood, retention pond, SWMM, urban drainage system
Procedia PDF Downloads 44610451 Electrode Performance of Carbon Coated Nanograined LiFePO4 in Lithium Batteries
Authors: Princess Stephanie P. Llanos, Rinlee Butch M. Cervera
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Lithium iron phosphate (LiFePO4) is a potential cathode material for lithium-ion batteries due to its promising characteristics. In this study, carbon-coated nanograined LiFePO4 is synthesized via wet chemistry method at a low temperature of 400 °C and investigated its performance as a cathode in Lithium battery. The X-ray diffraction pattern of the synthesized samples can be indexed to an orthorhombic LiFePO4 structure. Agglomerated particles that range from 200 nm to 300 nm are observed from scanning electron microscopy images. Transmission electron microscopy images confirm the crystalline structure of LiFePO4 and coating of amorphous carbon layer. Elemental mapping using Energy dispersive spectroscopy analysis revealed the homogeneous dispersion of Fe, P, O, and C elements. On the other hand, the electrochemical performances of the synthesized cathodes were investigated using cyclic voltammetry, galvanostatic charge/discharge tests with different C-rates, and cycling performances. Galvanostatic charge and discharge measurements revealed that the sample sintered at 400 °C for 3 hours with carbon coating demonstrated the highest capacity among the samples which reaches up to 160 mAhg⁻¹ at 0.1C rate.Keywords: cathode, charge-discharge, electrochemical, lithium batteries
Procedia PDF Downloads 33110450 A Polynomial Approach for a Graphical-based Integrated Production and Transport Scheduling with Capacity Restrictions
Authors: M. Ndeley
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The performance of global manufacturing supply chains depends on the interaction of production and transport processes. Currently, the scheduling of these processes is done separately without considering mutual requirements, which leads to no optimal solutions. An integrated scheduling of both processes enables the improvement of supply chain performance. The integrated production and transport scheduling problem (PTSP) is NP-hard, so that heuristic methods are necessary to efficiently solve large problem instances as in the case of global manufacturing supply chains. This paper presents a heuristic scheduling approach which handles the integration of flexible production processes with intermodal transport, incorporating flexible land transport. The method is based on a graph that allows a reformulation of the PTSP as a shortest path problem for each job, which can be solved in polynomial time. The proposed method is applied to a supply chain scenario with a manufacturing facility in South Africa and shipments of finished product to customers within the Country. The obtained results show that the approach is suitable for the scheduling of large-scale problems and can be flexibly adapted to different scenarios.Keywords: production and transport scheduling problem, graph based scheduling, integrated scheduling
Procedia PDF Downloads 47410449 A View from inside: Case Study of Social Economy Actors in Croatia
Authors: Drazen Simlesa, Jelena Pudjak, Anita Tonkovic Busljeta
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Regarding social economy (SE), Croatia is, on general level, considered as ex-communist country with good tradition, bad performance in second part of 20th Century because of political control in the business sector, which has in transition period (1990-1999) became a problem of ignorance in public administration (policy level). Today, social economy in Croatia is trying to catch up with other EU states on all important levels of SE sector: legislative and institutional framework, financial infrastructure, education and capacity building, and visibility. All four are integral parts of Strategy for the Development of Social Entrepreneurship in the Republic of Croatia for the period of 2015 – 2020. Within iPRESENT project, funded by Croatian Science Foundation, we have mapped social economy actors and after many years there is a clear and up to date social economy base. At the ICSE 2016 we will present main outcomes and results of this process. In the second year of the project we conducted a field research across Croatia carried out 19 focus groups with most influential, innovative and inspirational social economy actors. We divided interview questions in four themes: laws on social economy and public policies, definition/ideology of social economy and cooperation on SE scene, the level of democracy and working conditions, motivation and existence of intrinsic values. The data that are gathered through focus group interviews has been analysed via qualitative data analysis software (Atlas ti.). Major finding that will be presented in ICSA 2016 are: Social economy actors are mostly unsatisfied with legislative and institutional framework in Croatia and consider it as unsupportive and confusing. Social economy actors consider SE to be in the line with WISE model and as a tool for community development. The SE actors that are more active express satisfaction with cooperation amongst SE actors and other partners and stakeholders, but the ones that are in more isolated conditions (spatially) express need for more cooperation and networking. Social economy actors expressed their praise for democratic atmosphere in their organisations and fair working conditions. And finally, they expressed high motivation to continue to work in the social economy and are dedicated to the concept, including even those that were at the beginning interested just in getting a quick job. It means that we can detect intrinsic values for employees in social economy organisations. This research enabled us to describe for the first time in Croatia the view from the inside, attitudes and opinion of employees of social economy organisations.Keywords: employees, focus groups, mapping, social economy
Procedia PDF Downloads 25310448 The Psychometric Properties of the Team Climate Inventory Scale: A Validation Study in Jordan’s Collectivist Society
Authors: Suhair Mereish
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This research is aimed at examining the climate for innovation in organisations with the aim of validating the psychometric properties of the Team Climate Inventory (TCI -14) for Jordan’s collectivist society. The innovativeness of teams may be improved or obstructed by the climate within the team. Further, personal factors are considered an important element that influences the climate for innovation. Accordingly, measuring the employees' personality traits using the Big Five Inventory (BFI-44) could provide insights that aid in understanding how to improve innovation. Thus, studying the climate for innovation and its associations with personality traits is valuable, considering the insights it could offer on employee performance, job satisfaction, and well-being. Essentially, the Team Climate Inventory instrument has never been tested in Jordan’s collectivist society. Accordingly, in order to address the existing gap in the literature as a whole and, more specifically, in Jordan, it is essential to investigate its factorial structure and reliability in this particular context. It is also important to explore whether the factorial structure of the Team Climate Inventory in Jordan’s collectivist society demonstrates a similar or different structure to what has been found in individualistic ones. Lastly, examining if there are associations between the Team Climate Inventory and personality traits of Jordanian employees is pivotal. The quantitative study was carried out among Jordanian employees employed in two of the top 20 companies in Jordan, a shipping and logistics company (N=473) and a telecommunications company (N=219). To generalise the findings, this was followed by collecting data from the general population of this country (N=399). The participants completed the Team Climate Inventory. Confirmatory factor analyses and reliability tests were conducted to confirm the factorial structure, validity, and reliability of the inventory. Findings presented that the four-factor structure of the Team Climate Inventory in Jordan revealed a similar structure to the ones in Western culture. The four-factor structure has been confirmed with good fit indices and reliability values. Moreover, for climate for innovation, regression analysis identified agreeableness (positive) and neuroticism (negative) from the Big Five Inventory as significant predictors. This study will contribute to knowledge in several ways. First, by examining the reliability and factorial structure in a Jordanian collectivist context rather than a Western individualistic one. Second, by comparing the Team Climate Inventory structure in Jordan with findings for the Team Climate Inventory from Western individualistic societies. Third, by studying its relationships with personality traits in that country. Furthermore, findings from this study will assist practitioners in the field of organisational psychology and development to improve the climate for innovation for employees working in organisations in Jordan. It is also expected that the results of this research will provide recommendations to professionals in the business psychology sector regarding the characteristics of employees who hold positive and negative perceptions of the workplace climate.Keywords: big five inventory, climate for innovation, collectivism, individualism, Jordan, team climate inventory
Procedia PDF Downloads 5910447 Innovating and Disrupting Higher Education: The Evolution of Massive Open Online Courses
Authors: Nabil Sultan
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A great deal has been written on Massive Open Online Courses (MOOCs) since 2012 (considered by some as the year of the MOOCs). The emergence of MOOCs caused a great deal of interest amongst academics and technology experts as well as ordinary people. Some of the authors who wrote on MOOCs perceived it as the next big thing that will disrupt education. Other authors saw it as another fad that will go away once it ran its course (as most fads often do). But MOOCs did not turn out to be a fad and it is still around. Most importantly, they evolved into something that is beginning to look like a viable business model. This paper explores this phenomenon within the theoretical frameworks of disruptive innovations and jobs to be done as developed by Clayton Christensen and his colleagues and its implications for the future of higher education (HE).Keywords: MOOCs, disruptive innovations, higher education, jobs theory
Procedia PDF Downloads 27010446 Online Compressor Washing for Gas Turbine Power Output
Authors: Enyia James Diwa, Isaiah Thank-God Ebi, Dodeye Ina Igbong
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The privatization of utilities has brought about very strong competition in industries such as petrochemical and gas distribution among others, considering the continuous increase in cost of fuel. This has brought about the intense reason for gas turbine owners and operators to reduce and control performance degradation of the engine in other to minimize cost. The most common and very crucial problem of the gas turbine is the fouling of compressor, which is mostly caused by a reduction in flow capacity, compressor efficiency, and pressure ratio, this, in turn, lead to the engine compressor re-matching and output power and thermal efficiency reduction. The content of this paper encompasses a detailed presentation of the major causes, effects and control mechanism of fouling. The major emphasis is on compressor water washing to enable power augmentation. A modelled gas turbine similar to that of GE LM6000 is modelled for the current study, based on TURBOMATCH which is a Cranfield University software specifically made for gas turbine performance simulation and fouling detection. The compounded and intricate challenges of compressor online water washing of large output gas turbine are carried out. The treatment is applied to axial compressor used in the petrochemical and hydrocarbon industry.Keywords: gas turbine, fouling, degradation, compressor washing
Procedia PDF Downloads 34810445 An Intelligent Traffic Management System Based on the WiFi and Bluetooth Sensing
Authors: Hamed Hossein Afshari, Shahrzad Jalali, Amir Hossein Ghods, Bijan Raahemi
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This paper introduces an automated clustering solution that applies to WiFi/Bluetooth sensing data and is later used for traffic management applications. The paper initially summarizes a number of clustering approaches and thereafter shows their performance for noise removal. In this context, clustering is used to recognize WiFi and Bluetooth MAC addresses that belong to passengers traveling by a public urban transit bus. The main objective is to build an intelligent system that automatically filters out MAC addresses that belong to persons located outside the bus for different routes in the city of Ottawa. The proposed intelligent system alleviates the need for defining restrictive thresholds that however reduces the accuracy as well as the range of applicability of the solution for different routes. This paper moreover discusses the performance benefits of the presented clustering approaches in terms of the accuracy, time and space complexity, and the ease of use. Note that results of clustering can further be used for the purpose of the origin-destination estimation of individual passengers, predicting the traffic load, and intelligent management of urban bus schedules.Keywords: WiFi-Bluetooth sensing, cluster analysis, artificial intelligence, traffic management
Procedia PDF Downloads 24110444 The Relationship of Lean Management Principles with Lean Maturity Levels: Multiple Case Study in Manufacturing Companies
Authors: Alexandre D. Ferraz, Dario H. Alliprandini, Mauro Sampaio
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Companies and other institutions are constantly seeking better organizational performance and greater competitiveness. In order to fulfill this purpose, there are many tools, methodologies and models for increasing performance. However, the Lean Management approach seems to be the most effective in terms of achieving a significant improvement in productivity relatively quickly. Although Lean tools are relatively easy to understand and implement in different contexts, many organizations are not able to transform themselves into 'Lean companies'. Most of the efforts in its implementation have shown single benefits, failing to achieve the desired impact on the performance of the overall enterprise system. There is also a growing perception of the importance of management in Lean transformation, but few studies have empirically investigated and described the 'Lean Management'. In order to understand more clearly the ideas that guide Lean Management and its influence on the maturity level of the production system, the objective of this research is analyze the relationship between the Lean Management principles and the Lean maturity level in the organizations. The research also analyzes the principles of Lean Management and its relationship with the 'Lean culture' and the results obtained. The research was developed using the case study methodology. Three manufacturing units of a German multinational company from industrial automation segment, located in different countries were studied, in order to have a better comparison between the practices and the level of maturity in the implementation. The primary source of information was the application of a research questionnaire based on the theoretical review. The research showed that higher the level of Lean Management principles, higher are the Lean maturity level, the Lean culture level, and the level of Lean results obtained in the organization. The research also showed that factors such as time for application of Lean concepts and company size were not determinant for the level of Lean Management principles and, consequently, for the level of Lean maturity in the organization. The characteristics of the production system showed much more influence in different evaluated aspects. The present research also left recommendations for the managers of the plants analyzed and suggestions for future research.Keywords: lean management, lean principles, lean maturity level, lean manufacturing
Procedia PDF Downloads 14310443 Performance Evaluation of Vermiculite as Adsorbent Material for Solar-Assisted Air-Conditioning in Tropical Climate
Authors: Norhayati Mat Wajid, Abdul Murad Zainal Abidin, Hasila Jarimi, Kamaruzaman Sopian, Adnan Ibrahim, Ahmad Fazlizan, Afif Safwan
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Solar-adsorption air-conditioning system (SADCS) is an alternative to the conventional vapor compression system (VCS). SADCS have advantages over VCS system, such as 1) a green cooling technology which utilizes solar energy to drive the adsorption/desorption cycle, 2) can be operated using green refrigerant HFC free pure water, 3) mechanically simpler, and 4) lower operating noise level since it has no moving parts other than the magnetic valves. Several advancements have been achieved in these fields in the last decade, but further research is still needed to escalate this technology to a practical level. Hence, this paper presents a literature survey and a review that add insights into the current state-of-the-art of SADCS technologies with emphasis on the practical researches that were conducted at the laboratory scale and commercial level. In this paper, the performance evaluation of vermiculite as adsorbent material for SADCS in tropical climate discussed in comparison to other adsorbent material such as silica gel.Keywords: adsorption cooling, solar-assisted cooling, HVAC, tropical climate, solar thermal
Procedia PDF Downloads 15410442 Combined Effect of Roughness and Suction on Heat Transfer in a Laminar Channel Flow
Authors: Marzieh Khezerloo, Lyazid Djenidi
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Owing to wide range of the micro-device applications, the problems of mixing at small scales is of significant interest. Also, because most of the processes produce heat, it is needed to develop and implement strategies for heat removal in these devices. There are many studies which focus on the effect of roughness or suction on heat transfer performance, separately, although it would be useful to take advantage of these two methods to improve heat transfer performance. Unfortunately, there is a gap in this area. The present numerical study is carried to investigate the combined effects of roughness and wall suction on heat transfer performance of a laminar channel flow; suction is applied on the top and back faces of the roughness element, respectively. The study is carried out for different Reynolds numbers, different suction rates, and various locations of suction area on the roughness. The flow is assumed two dimensional, incompressible, laminar, and steady state. The governing Navier-Stokes equations are solved using ANSYS-Fluent 18.2 software. The present results are tested against previous theoretical results. The results show that by adding suction, the local Nusselt number is enhanced in the channel. In addition, it is shown that by applying suction on the bottom section of the roughness back face, one can reduce the thickness of thermal boundary layer, which leads to an increase in local Nusselt number. This indicates that suction is an effective means for improving the heat transfer rate (suction by controls the thickness of thermal boundary layer). It is also shown that the size and intensity of vortical motion behind the roughness element, decreased with an increasing suction rate, which leads to higher local Nusselt number. So, it can be concluded that by using suction, strategically located on the roughness element, one can control both the recirculation region and the heat transfer rate. Further results will be presented at the conference for coefficient of drag and the effect of adding more roughness elements.Keywords: heat transfer, laminar flow, numerical simulation, roughness, suction
Procedia PDF Downloads 11310441 Performance of the Cmip5 Models in Simulation of the Present and Future Precipitation over the Lake Victoria Basin
Authors: M. A. Wanzala, L. A. Ogallo, F. J. Opijah, J. N. Mutemi
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The usefulness and limitations in climate information are due to uncertainty inherent in the climate system. For any given region to have sustainable development it is important to apply climate information into its socio-economic strategic plans. The overall objective of the study was to assess the performance of the Coupled Model Inter-comparison Project (CMIP5) over the Lake Victoria Basin. The datasets used included the observed point station data, gridded rainfall data from Climate Research Unit (CRU) and hindcast data from eight CMIP5. The methodology included trend analysis, spatial analysis, correlation analysis, Principal Component Analysis (PCA) regression analysis, and categorical statistical skill score. Analysis of the trends in the observed rainfall records indicated an increase in rainfall variability both in space and time for all the seasons. The spatial patterns of the individual models output from the models of MPI, MIROC, EC-EARTH and CNRM were closest to the observed rainfall patterns.Keywords: categorical statistics, coupled model inter-comparison project, principal component analysis, statistical downscaling
Procedia PDF Downloads 36810440 Effect of Core Stability Exercises on Balance between Trunk Muscles in Healthy Adult Subjects
Authors: Amir A. Beltagi, Ahmed R. Abdelbaki
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Background: Core stability training has recently attracted attention for optimizing performance and improving muscle balance for healthy and unhealthy individuals. The purpose of this study was to investigate the effect of beginner’s core stability exercises on the trunk flexors’/extensors’ peak torque ratio and trunk flexors’ and extensors’ peak torques. Methods: Thirty five healthy individuals, randomly assigned into two groups; experimental (group I) and control (group II), participated in the study. Group I involved 20 participants (10 male & 10 female) with mean ±SD age, weight, and height of 20.7±2.4 years, 66.5±12.1 kg and 166.7±7.8 cm respectively. Group II involved 15 participants (6 male & 9 female) with mean ±SD age, weight, and height of 20.3±0.61 years, 68.57±12.2 kg and 164.28 ±7.59 cm respectively. Data were collected using the Biodex Isokinetic system. The participants were tested twice; before and after a 6-week period during which the experimental group performed a core stability training program. Findings: Statistical analysis using the 2x2 Mixed Design ANOVA revealed that there were no significant differences in the trunk flexors’/extensors’ peak torque ratio between the ‘pre’ and ‘post’ tests for either group (p > 0.025). Moreover, there were no significant differences in the trunk flexors’/extensors’ ratios between both groups at either test (p > 0.025). Meanwhile, the 2x2 Mixed Design MANOVA revealed that there were significant differences in the trunk flexors’ and extensors’ peak torques between the ‘pre’ and ‘post’ tests for group I (p < 0.025), while there were no significant differences inbetween for group II (p > 0.025). Moreover, there were no significant differences between both groups for the tested muscles’ peak torques at either test except for that of the trunk flexors at the ‘post’ test only (p < 0.025). Interpretation: The improvement in muscle performance indicated by the increase in the trunk flexors’ and extensors’ peak torques in the experimental group recommends including core stability training in the exercise programs that aim to improve muscle performance.Keywords: core stability, isokinetic, trunk muscles, muscle balance
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