Search results for: high performance organization

Authors: Gwani M., Umar M. Kangiwa, Bello A. Umar, Gado A. Abubakar

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The increasing demand for sustainable energy solutions has driven significant interest in the development of innovative designs of wind turbines. The horizontal axis wind turbine (HAWT) and the vertical axis wind turbine (VAWT) are the dominant type of wind turbine used for power generation. However, these turbines have their respective merits and demerits, which affect their performance. This study introduces a Hybrid Cross Axis Wind Turbine (HCAWT), which integrates the blades of both horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs) in a cross-axis configuration with a Savonius rotor to form a hybrid system. The HCAWT combines the self-starting capabilities of Savonius rotors with the high-efficiency characteristics of Darrieus rotors and HAWT, aiming to optimize performance across a range of wind conditions. The performance of the HCAWT was tested and evaluated against a cross-axis wind turbine (CAWT) and a conventional VAWT under similar experimental conditions. The study’s results indicate that the HCAWT outperformed both the CAWT and the conventional VAWT. The power coefficient (Cp) of the HCAWT increases by 83% and 132% compared to that of the CAWT and conventional VAWT, respectively. The findings show that the HCAWT offers better start-up performance and maintains higher efficiency at lower wind speeds compared to CAWT and conventional VAWT. The findings suggest that the HCAWT offers significant improvements in energy capture, particularly in turbulent wind conditions, and greater adaptability to changing wind conditions, making it a viable option for both urban and rural energy applications.

Keywords: renewable energy, hybrid, cross axis wind turbine, energy efficiency

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Authors: H. Lahlali F. El Haouzi, A.M.Al-Baradi, I. El Aboudi, M. El Azhari, A. Mdarhri

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Polytetrafluoroethylene (PTFE) is a high performance thermoplastic polymer with exceptional physical and chemical properties, such as a high melting temperature, high thermal stability, and very good chemical resistance. Nevertheless, manufacturing PTFE is problematic due to its high melt viscosity (10 12 Pa.s). In practice, it is by now well established that this property presents a serious problem when the classical methods are used to synthesized the dense PTFE materials in particularly hot pressing, high temperature extrusion. In this framework, we use here a new process namely spark plasma sintering (SPS) to elaborate PTFE samples from the micro metric particles powder. It consists in applying simultaneous electric current and pressure directly on the sample powder. By controlling the processing parameters of this technique, a series of PTFE samples are easy obtained and associated to remarkably short time as is reported in an early work. Our central goal in the present study is to understand how the non conventional SPS affects the mechanical properties at room temperature. For this end, a second commercially series of PTFE synthesized by using the extrusion method is investigated. The first data according to the tensile mechanical properties are found to be superior for the first set samples (SPS). However, this trend is not observed for the results obtained from the compression testing. The observed macro-behaviors are correlated to some physical properties of the two series of samples such as their crystallinity or density. Upon a close examination of these properties, we believe the SPS technique can be seen as a promising way to elaborate the polymer having high molecular mass without compromising their mechanical properties.

Keywords: PTFE, extrusion, Spark Plasma Sintering, physical properties, mechanical behavior

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Authors: Cromwell F. Gopo, Joy L. Picar

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This study aimed to predict the employability of senior high school graduates for S.Y. 2018- 2019 in the Davao del Norte Division through quantitative research design using the descriptive status and predictive approaches among the indicated parameters, namely gender, school type, academics, academic award recipient, skills, values, and strand. The respondents of the study were the 33 secondary schools offering senior high school programs identified through simple random sampling, which resulted in 1,530 cases of graduates’ secondary data, which were analyzed using frequency, percentage, mean, standard deviation, and binary logistic regression. Results showed that the majority of the senior high school graduates who come from large schools were females. Further, less than half of these graduates received any academic award in any semester. In general, the graduates’ performance in academics, skills, and values were proficient. Moreover, less than half of the graduates were not employed. Then, those who were employed were either contractual, casual, or part-time workers dominated by GAS graduates. Further, the predictors of employability were gender and the Information and Communications Technology (ICT) strand, while the remaining variables did not add significantly to the model. The null hypothesis had been rejected as the coefficients of the predictors in the binary logistic regression equation did not take the value of 0. After utilizing the model, it was concluded that Technical-Vocational-Livelihood (TVL) graduates except ICT had greater estimates of employability.

Keywords: employability, senior high school graduates, Davao del Norte, Philippines

Procedia PDF Downloads 158

Authors: Ruba Hamed, Khaled Hussainey, Basiem Al-Shattarat, Wasim Al-Shattarat

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This paper examines how the influence of mandating corporate social responsibility reporting (CSR) on subsequent financial performance through accounting-based measures and market-based measures. We provide evidence about the negative impact of reporting CSR voluntarily on the firm’s future performance due to the increased spending on and costs related to such activities. On the contrary, mandating CSR reporting enhances firms’ future performance by signalling to the market about the firm’s positive stance towards sustainability issues in the UK. Our findings are of interest to regulation setters and stakeholders with respect to mandatory CSR reporting and provide further insight and feedback into accounting and reporting practices.

Keywords: accounting-based performance, mandatory CSR, mandatory regulation, market-based performance

Procedia PDF Downloads 129

Authors: Ruyang Ren, Yaohua Zhao, Yanhua Diao

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The intermittent and unstable characteristics of renewable energy such as solar energy can be effectively solved through battery energy storage system. Lithium-ion battery is widely used in battery energy storage system because of its advantages of high energy density, small internal resistance, low self-discharge rate, no memory effect and long service life. However, the performance and service life of lithium-ion battery is seriously affected by its operating temperature. Thus, the safety operation of the lithium-ion battery module is inseparable from an effective thermal management system (TMS). In this study, a new type of TMS based on micro heat pipe array (MHPA) for lithium-ion battery is established, and the TMS is applied to a battery energy storage box that needs to operate at a high temperature environment of 40 °C all year round. MHPA is a flat shape metal body with high thermal conductivity and excellent temperature uniformity. The battery energy storage box is composed of four battery modules, with a nominal voltage of 51.2 V, a nominal capacity of 400 Ah. Through the excellent heat transfer characteristics of the MHPA, the heat generated by the charge and discharge process can be quickly transferred out of the battery module. In addition, if only the MHPA cannot meet the heat dissipation requirements of the battery module, the TMS can automatically control the opening of the external fan outside the battery module according to the temperature of the battery, so as to further enhance the heat dissipation of the battery module. The thermal management performance of lithium-ion battery TMS based on MHPA is studied experimentally under different ambient temperatures and the condition to turn on the fan or not. Results show that when the ambient temperature is 40 °C and the fan is not turned on in the whole charge and discharge process, the maximum temperature of the battery in the energy storage box is 53.1 °C and the maximum temperature difference in the battery module is 2.4 °C. After the fan is turned on in the whole charge and discharge process, the maximum temperature is reduced to 50.1 °C, and the maximum temperature difference is reduced to 1.7 °C. Obviously, the lithium-ion battery TMS based on MHPA not only could control the maximum temperature of the battery below 55 °C, but also ensure the excellent temperature uniformity of the battery module. In conclusion, the lithium-ion battery TMS based on MHPA can ensure the safe and stable operation of the battery energy storage box in high temperature environment.

Keywords: heat dissipation, lithium-ion battery thermal management, micro heat pipe array, temperature uniformity

Procedia PDF Downloads 186

Authors: Nadeem A. Siddique, Mohd Mujeeb, Kahkashan

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Introduction: The objective of the projected work is to study the occurrence of the aflatoxins B1, B2, G1and G2 in remedial plants, exclusively in Delphinium denudatum. The aflatoxins were analysed by high-performance liquid chromatography–tandem quadrupole mass spectrometry with electrospray ionization (HPLC–MS/MS) and immunoaffinity column chromatography were used for extraction and purification of aflatoxins. PDA media was selected for fungal count. Results: A good quality linear relationship was originated for AFB1, AFB2, AFG1 and AFG2 at 1–10 ppb (r > 0.9995). The analyte precision at three different spiking levels was 88.7–109.1 %, by means of low per cent relative standard deviations in each case. Within 5 to7 min aflatoxins can be separated using an Agilent XDB C18-column. We found that AFB1 and AFB2 were not found in D. denudatum. This was reliable through exceptionally low figures of fungal colonies observed after 6 hr of incubation. The developed analytical method is straightforward, be successfully used to determine the aflatoxins. Conclusion: The developed analytical method is straightforward, simple, accurate, economical and can be successfully used to find out the aflatoxins in remedial plants and consequently to have power over the quality of products. The presence of aflatoxin in the plant extracts was interrelated to the least fungal load in the remedial plants examined.

Keywords: aflatoxins, delphinium denudatum, liquid chromatography, mass spectrometry

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Authors: Wissal Ben Arfi, Jean-Michel Sahut

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The purpose of this paper is to provide a deeper understanding of the succession process from a knowledge management perspective. By doing that, succession process in family businesses, as an environment for creating and sharing knowledge, was explored. Design/Methodology/Approach: To support our reasoning, we collected qualitative data through 16 in-depth interviews conducted with all decision makers involved in the family businesses succession process in France. These open-ended responses were subsequently exposed to thematic discourse analysis. Findings: Central to this exhibit is the nature and magnitude of knowledge creation and sharing among the actors within the family succession context and how can tacit knowledge sharing facilitate the succession process. We also identified factors that inhibit down the knowledge creation and sharing processes. The sharing and creation of knowledge among members of a family business appear to be a complex process that must be part of a strategy for change. This implies that it requests trust and takes a certain amount of time because it requires organizational change and a clear and coherent strategic vision that is accepted and assimilated by all the members. Professional and leadership skills are of particular importance in knowledge sharing and creation processes. In most cases, tacit knowledge is crucial when it is shared and accumulated collectively. Our findings reveal that managers should find ways of implementing knowledge sharing and creation processes while acknowledging the succession process within family firms. This study highlights the importance of generating knowledge strategies in order to enhance the performance and the success of intergenerational succession. The empirical outcomes contribute to enrich the field of succession management process and enhance the role of knowledge in shaping family performance and longevity. To a large extent, the lessons learned from the study of succession processes in family-owned businesses are that when there is a deliberate effort to introduce a knowledge-based approach, this action becomes a seminal event in the life of the organization. Originality/Value: The paper contributes to the deep understanding of interactions among actors by examining the knowledge creation and sharing processes since current researches in family succession focused on aspects such as personal development of potential, intra-family succession intention, decision-making processes in family businesses. Besides, as succession is one of the key factors that determine the longevity and the performance of family businesses, it also contributes to literature by examining how tacit knowledge is transferred, shared and created in family businesses and how this can facilitate the intergenerational succession process.

Keywords: family-owned businesses, succession process, knowledge, performance

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Authors: Cise Unluer

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Reactive MgO hydrates to form brucite (Mg(OH)2, magnesium hydroxide), which can then react with CO2 and additional water to form a range of strength providing hydrated magnesium carbonates (HMCs) within cement-based formulations. The presented work focuses on the use of reactive MgO in a range of concrete mixes, where it carbonates by absorbing CO2 and gains strength accordingly. The main goal involves maximizing the amount of CO2 absorbed within construction products, thereby reducing the overall environmental impact of the designed formulations. Microstructural analyses including scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetry/differential thermal analysis (TG/DTA) are used in addition to porosity, permeability and unconfined compressive strength (UCS) testing to understand the performance mechanisms. XRD Reference Intensity Ratio (RIR), acid digestion and TG/DTA are utilized to quantify the amount of CO2 sequestered, with the goal of achieving 100% carbonation through careful mix design, leading to a range of carbon neutral products with high strengths. As a result, samples stronger than those containing Portland cement (PC) were produced, revealing the link between the mechanical performance and microstructural development of the developed formulations with the amount of CO2 sequestered.

Keywords: carbonation, compressive strength, reactive MgO cement, sustainability

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Authors: B. G. Abiona, T. D. Odetayo, S. O. Adeogun, O. E. Fakoya

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This study determined the effects of workplace power on employees’ job performance in selected federal universities of agriculture in Nigeria. Two hundred and twenty-seven (227) employees were randomly drawn from the selected universities through a multistage sampling procedure. The mean age of the employees was 38 years, mostly (60.8%) male. Results indicated that the overall job performance was significantly influenced by an expert (b = 0.287, p<0.01) and legitimate power (b = -0.279, p<0.05). The findings clearly showed that supervisor has considerable professional experience to draw from in helping subordinates to do their work better because they have specialized training in their field of study, and subordinates prefer to do what the supervisor suggests because of their professional expertise, which greatly influences employees’ job performance. A policy that will ensure transparency in all administrative procedures, with a formal line of authority that will enhance the thriving of legitimate power, should be established within organisation is recommended.

Keywords: workplace power, employees, job performance, agricultural unversities

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Authors: Boyu Li

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Mixed matrix membranes (MMMs), as a separation technology, can improve CO₂ recycling efficiency and reduce the environmental impacts associated with huge emissions. Nevertheless, many challenges must be overcome to design excellent selectivity and permeability performance MMMs. Herein, this work demonstrates the design of nano-scale GNPs (Cu-BDC@PEG) with strong compatibility and high free friction volume (FFV) is an effective way to construct non-interfacial voids MMMs with a desirable combination of selectivity and permeability. Notably, the FFV boosted thanks to the chain length and shape of the GNPs. With this, the permeability and selectivity of Cu-BDC@PEG/PVDF MMMs had also been significantly improved. As such, compatible Cu-BDC@PEG proves very efficient for resolving challenges of MMMs with poor compatibility on the basis of the interfacial defect. Poly (Ethylene Glycol) (PEG) with oxygen groups can be finely coordinated with Cu-MOFs to disperse Cu-BDC@PEG homogenously and form hydrogen bonds with matrix to achieve continuous phase. The resultant MMMs exhibited a simultaneous enhancement of gas permeability (853.1 Barrer) and ideal CO₂/N selectivity (41.7), which has surpassed Robenson's upper bound. Moreover, Cu-BDC@PEG/PVDF has a high-temperature resistance and a long time sustainably. This attractive separation performance of Cu-BDC@PEG/PVDF offered an exciting platform for the development of composite membranes for sustainable CO₂ separations.

Keywords: metal organic framework, CO₂ separation, mixed matrix membrane, polymer

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Authors: Mingchuan Zhou, Haitao Zhang, Hongfang Ma, Weiyong Ying

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Alumina supported platinum and tin catalysts with different loadings of Pt and Sn were prepared and characterized by low temperature N₂ adsorption/desorption, H₂-temperature programed reduction and CO pulse chemisorption. Pt and Sn below 1% loading were suitable for acetic acid hydrogenation. The best performance over 0.75Pt1Sn/Al₂O₃ can reach 87.55% conversion of acetic acid and 47.39% selectivity of ethanol. The operating conditions of acetic acid hydrogenation over 1Pt1Sn/Al₂O₃ were investigated. High reaction temperature can enhance the conversion of acetic acid, but it decreased total selectivity of ethanol and acetyl acetate. High pressure and low weight hourly space velocity were beneficial to both conversion of acetic acid and selectivity to ethanol.

Keywords: acetic acid, hydrogenation, operating condition, PtSn

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Authors: Konstantinos Metaxiotis, Konstantinos Liagkouras

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The objective of this study is to examine the performance of three well-known multiobjective evolutionary algorithms for solving optimization problems. The first algorithm is the Non-dominated Sorting Genetic Algorithm-II (NSGA-II), the second one is the Strength Pareto Evolutionary Algorithm 2 (SPEA-2), and the third one is the Multiobjective Evolutionary Algorithms based on decomposition (MOEA/D). The examined multiobjective algorithms are analyzed and tested on the ZDT set of test functions by three performance metrics. The results indicate that the NSGA-II performs better than the other two algorithms based on three performance metrics.

Keywords: MOEAs, multiobjective optimization, ZDT test functions, evolutionary algorithms

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Authors: Yue-Tzu Yang, Peng-Jen Chen

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The present study deals with the numerical optimization of wavy channel with the help of genetic algorithm (GA). Three design variables related to the wave amplitude (A), the wavelength (λ) and the channel aspect ratio (α) are chosen and their ranges are decided through preliminary calculations of three-dimensional Navier-stokes and energy equations. A parametric study is also performed to show the effects of different design variables on the overall performance of the wavy channel. Objective functions related to the heat transfer and pressure drop, performance factor (PF) is formulated to analyze the performance of the wavy channel. The numerical results show that the wave amplitude and the channel aspect ratio have significant effects on the thermal performance. It can improve the performance of the wavy channels by increasing wave amplitude or decreasing the channel aspect ratio. Increasing wavelengths have no significant effects on the heat transfer performance.

Keywords: wavy channel, genetic algorithm, optimization, numerical simulation

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Authors: Sudipto Jana

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Background and significance of the study: Banking industry performs as a catalyst for industrial growth and agricultural growth, however, as well involves the existence and welfare of the citizens. The banking system in India was described by unmatched growth and the recreation of bunch making in the pre-liberalization era. At the time of financial sector reforms Reserve Bank of India issued a regulatory norm concerning capital adequacy, income recognition, asset classification and provisioning that have increasingly precede meeting by means of the international paramount performs. Bank management ceaselessly manages the triumph, effectiveness, productivity and performance of the bank as good performance, high productivity and efficiency authorizes the triumph of the bank management targets as well as aims of bank. In a comparable move toward performance of any economy depends upon the expediency and effectiveness of its financial system of nation establishes its economic growth indicators. Profitability and productivity are the most important relevant parameters of any banking group. Keeping in view of this, this study examines the profitability and productivity performance of the selected public sector banks in India. Methodology: This study is based on secondary data obtained from Reserve Bank of India database for the periods between 2006 and 2015. This study purposively selects four types of commercial banks, namely, State Bank of India, United Bank of India, Punjab National Bank and Allahabad Bank. In order to analyze the performance with relation to profitability and productivity, productivity performance indicators in terms of capital adequacy ratio, burden ratio, business per employee, spread per employee and advances per employee and profitability performance indicators in terms of return on assets, return on equity, return on advances and return on branch have been considered. In the course of analysis, descriptive statistics, correlation statistics and multiple regression have been used. Major findings: Descriptive statistics indicate that productivity performance of State Bank of India is very satisfactory than other public sector banks in India. But management of productivity is unsatisfactory in case of all the public sector banks under study. Correlation statistics point out that profitability of the public sector banks are strongly positively related with productivity performance in case of all the public sector banks under study. Multiple regression test results show that when profitability increases profit per employee increases and net non-performing assets decreases. Concluding statements: Productivity and profitability performance of United Bank of India, Allahabad Bank and Punjab National Bank are unsatisfactory due to poor management of asset quality as well as management efficiency. It needs government’s interference so that profitability and productivity performance are increased in the near future.

Keywords: India, productivity, profitability, public sector banks

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Authors: Mamman Jimoh Ahmadu, Sanusi Abubakar Sadiq, Eldah Ephraim Buba

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In modern societies, stress has become a widespread phenomenon and therefore an issue of major concern to employees, organizations, and the state. As senior management of an organization, executives are not immune to this problem because they carry out lots of activities while on duty. This paper is centered on the benefits of Tourism, Leisure and Recreation to the management of executive stress. Executives work has always been considered to be stressful. The key objective of the research is to gain a better understanding of the causes of stress among executives and to find out how tourism, leisure, and recreational activities could be used as a means to managing stress. Interview and observation data were analyzed using SPSS. The major finding revealed that that human system has specific limitations and nature cannot be cheated. It is recommended that executives should take regular and mandatory vacation of least forty days in a year. The only answer then is rest. The research recommends that a break tends to improves and relaxes, refreshes the mind and enhances performance.

Keywords: executive, recreation, stress, tourism

Procedia PDF Downloads 358

Authors: Si-Jie Ji, Santhanamoorthi Nachimuthu, Jyh-Chiang Jiang

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With the rapid development of industrialization and urbanization, air pollution poses significant global environmental challenges, contributing to acid rain, global warming, and adverse health effects. Therefore, it is necessary to monitor the concentration of toxic gases in the atmospheric environment in real-time and to deploy cost-effective gas sensors capable of detecting their emissions. In this study, we systematically investigated the sensing capabilities of the two-dimensional MoSe₂ for seven key environmental gases (NO, NO₂, CO, CO₂, SO₂, SO₃, and O₂) using density functional theory (DFT) and non-equilibrium Green’s function (NEGF) calculations. We also investigated the impact of H₂O as an interfering gas. Our results indicate that the MoSe₂ monolayer is thermodynamically stable and exhibits strong gas-sensing capabilities. The calculated adsorption energies indicate that these gases can stably adsorb on MoSe₂, with SO₃ exhibiting the strongest adsorption energy (-0.63 eV). Electronic structure analysis, including projected density of states (PDOS) and Bader charge analysis, demonstrates significant changes in the electronic properties of MoSe₂ upon gas adsorption, affecting its conductivity and sensing performance. We find that oxygen (O₂) adsorption notably influenced the deformation of MoSe₂. To comprehensively understand the potential of MoSe₂ as a gas sensor, we used the NEGF method to assess the electronic transport properties of MoSe₂ under gas adsorption, evaluating current-voltage (I-V), resistance-voltage (R-V) characteristics, and transmission spectra to determine sensitivity, selectivity, and recovery time compared to pristine MoSe₂. Sensitivity, selectivity, and recovery time are analyzed at a bias voltage of 1.7V, showing excellent performance of MoSe₂ in detecting SO₃, among other gases. The pronounced changes in electronic transport behavior induced by SO₃ adsorption confirm MoSe₂’s strong potential as a high-performance gas-sensing material. Overall, this theoretical study provides new insights into the development of high-performance gas sensors, demonstrating the potential of MoSe₂ as a gas-sensing material, particularly for gases like SO₃.

Keywords: density functional theory, gas sensing, MoSe₂, non-equilibrium Green’s function, SO

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Authors: Israa Al-Neami, Ali J. Al-Askery, Martin Johnston, Charalampos Tsimenidis

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In this paper, we focus on the design of a multi-line copper wire (MLCW) communication system. First, we construct our proposed MLCW channel and verify its characteristics based on the Kolmogorov-Smirnov test. In addition, we apply Middleton class A impulsive noise (IN) to the copper channel for further investigation. Second, the MIMO G.fast system is adopted utilizing the proposed MLCW channel model and is compared to a single line G-fast system. Second, the performance of the coded system is obtained utilizing concatenated interleaved Reed-Solomon (RS) code with four-dimensional trellis-coded modulation (4D TCM), and compared to the single line G-fast system. Simulations are obtained for high quadrature amplitude modulation (QAM) constellations that are commonly used with G-fast communications, the results demonstrate that the bit error rate (BER) performance of the coded MLCW system shows an improvement compared to the single line G-fast systems.

Keywords: G.fast, Middleton Class A impulsive noise, mitigation techniques, Copper channel model

Procedia PDF Downloads 135

Authors: Margit Kastner

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To overcome the negative consequences associated with large class sizes and to support students in developing the necessary competences (e.g., critical thinking, problem-solving, or team-work skills) a marketing course has been redesigned by implementing project-based learning with peer assessment (PBL&PA). This means that students can voluntarily take advantage of this supplementary offer and explore -in addition to attending the lecture where clicker questions are asked- a real-world problem, find a solution, and assess the results of peers while working in small collaborative groups. In order to handle this with little further effort, the process is technically supported by the university’s e-learning system in such a way that students upload their solution in form of an assignment which is then automatically distributed to peer groups who have to assess the work of three other groups. Finally, students’ work is graded automatically considering both, students’ contribution to the project and the conformity of the peer assessment. The purpose of this study is to evaluate students’ perception of PBL&PA using an online-questionnaire to collect the data. More specifically, it aims to discover students’ motivations for (not) working on a project and the benefits and problems students encounter. In addition to the survey, students’ performance was analyzed by comparing the final grades of those who participated in PBL&PA with those who did not participate. Among the 260 students who filled out the questionnaire, 47% participated in PBL&PA. Besides extrinsic motivations (bonus credits), students’ participation was often motivated by learning and social benefits. Reasons for not working on a project were connected to students’ organization and management of their studies (e.g., time constraints, no/wrong information) and teamwork concerns (e.g., missing engagement of peers, prior negative experiences). In addition, high workload and insufficient extrinsic motivation (bonus credits) were mentioned. With regards to benefits and problems students encountered during the project, students provided more positive than negative comments. Positive aspects most often stated were learning and social benefits while negative ones were mainly attached to the technical implementation. Interestingly, bonus credits were hardly named as a positive aspect meaning that intrinsic motivations have become more important when working on the project. Team aspects generated mixed feelings. In addition, students who voluntarily participated in PBL&PA were, in general, more active and utilized further course offers such as clicker questions. Examining students’ performance at the final exam revealed that students without participating in any of the offered active learning tasks performed poorest in the exam while students who used all activities were best. In conclusion, the goals of the implementation were met in terms of students’ perceived benefits and the positive impact on students’ exam performance. Since the comparison of the automatic grading with faculty grading showed valid results, it is possible to rely only on automatic grading in the future. That way, the additional workload for faculty will be within limits. Thus, the implementation of project-based learning with peer assessment can be recommended for large classes.

Keywords: automated grading, large classes, peer assessment, project-based learning

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Authors: Luís F. da Silva, Ariadne C. Catto, Osmando F. Lopes, Khalifa Aguir, Valmor R. Mastelaro, Caue Ribeiro, Elson Longo

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Gas detection is important for controlling industrial, and vehicle emissions, agricultural residues, and environmental control. In last decades, several semiconducting oxides have been used to detect dangerous or toxic gases. The excellent gas-sensing performance of these devices have been observed at high temperatures (~250 °C), which forbids the use for the detection of flammable and explosive gases. In this way, ultraviolet light activated gas sensors have been a simple and promising alternative to achieve room temperature sensitivity. Among the semiconductor oxides which exhibit a good performance as gas sensor, the zinc oxide (ZnO) and tin oxide (SnO2) have been highlighted. Nevertheless, their poor selectivity is the main disadvantage for application as gas sensor devices. Recently, heterostructures combining these two semiconductors (ZnO-SnO2) have been studied as an alternative way to enhance the gas sensor performance (sensitivity, selectivity, and stability). In this work, we investigated the influence of mass ratio Zn:Sn on the properties of ZnO-SnO2 nanocomposites prepared by hydrothermal treatment for 4 hours at 200 °C. The crystalline phase, surface, and morphological features were characterized by X-ray diffraction (XRD), high-resolution transmission electron (HR-TEM), and X-ray photoelectron spectroscopy (XPS) measurements. The gas sensor measurements were carried out at room-temperature under ultraviolet (UV) light irradiation using different ozone levels (0.06 to 0.61 ppm). The XRD measurements indicate the presence of ZnO and SnO2 crystalline phases, without the evidence of solid solution formation. HR-TEM analysis revealed that a good contact between the SnO2 nanoparticles and the ZnO nanorods, which are very important since interface characteristics between nanostructures are considered as challenge to development new and efficient heterostructures. Electrical measurements proved that the best ozone gas-sensing performance is obtained for ZnO:SnO2 (50:50) nanocomposite under UV light irradiation. Its sensitivity was around 6 times higher when compared to SnO2 pure, a traditional ozone gas sensor. These results demonstrate the potential of ZnO-SnO2 heterojunctions for the detection of ozone gas at room-temperature when irradiated with UV light irradiation.

Keywords: hydrothermal, zno-sno2, ozone sensor, uv-activation, room-temperature

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Authors: Selvam M., Vadthya Poornachandar, Surender Singh

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These Reclaimed Asphalt Pavement (RAP) aggregates are generally dumped in the open area after the demolition of Asphalt Pavements. The utilization of RAP aggregates in cement concrete pavements may provide several socio-economic-environmental benefits and could embrace the circular economy. The cross recycling of RAP aggregates in the concrete pavement could reduce the consumption of virgin aggregates and saves the fertile land. However, the structural, as well as functional properties of RAP-concrete could be significantly lower than the conventional Pavement Quality Control (PQC) pavements. This warrants judicious selection of RAP fraction (coarse and fine aggregates) along with the accurate proportion of the same for PQC highways. Also, the selection of the RAP fraction and its proportion shall not be solely based on the mechanical properties of RAP-concrete specimens but also governed by the structural and functional behavior of the pavement system. In this study, an effort has been made to predict the optimum RAP fraction and its corresponding proportion for cement concrete pavements by considering the low-volume and high-volume roads. Initially, the effect of inclusions of RAP on the fresh and mechanical properties of concrete pavement mixes is mapped through an extensive literature survey. Almost all the studies available to date are considered for this study. Generally, Indian Roads Congress (IRC) methods are the most widely used design method in India for the analysis of concrete pavements, and the same has been considered for this study. Subsequently, fatigue damage analysis is performed to evaluate the required safe thickness of pavement slab for different fractions of RAP (coarse RAP). Consequently, the performance of RAP-concrete is predicted by employing the AASHTO-1993 model for the following distresses conditions: faulting, cracking, and smoothness. The performance prediction and total cost analysis of RAP aggregates depict that the optimum proportions of coarse RAP aggregates in the PQC mix are 35% and 50% for high volume and low volume roads, respectively.

Keywords: concrete pavement, RAP aggregate, performance prediction, pavement design

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Authors: Mitku Malede Ymer

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The study was mainly intended to explore the impact of asset diversification on the financial performance of thirteen purposely selected Ethiopian commercial banks with seven consecutive years of data for the period 2011-2017, considering the availability of data. An explanatory research design has been employed to determine the impact of asset diversification on financial performance. In the meantime, a quantitative approach was used to construct the empirical model. Banks’ financial performance was measured using return on asset, and the four variables used to measure asset diversification were cash holding, fixed assets, foreign deposits, and NBE Bills, which were predictor variables. Again, the size of the bank was considered as a control variable. Then, a pooled panel regression model was employed to analyze the collected data. The result pretends that cash holding has a positive but marginally insignificant effect on financial performance, fixed assets, and foreign bank deposits have a positive and significant effect on financial performance, and NBE Bills have a negative and significant effect on banks' financial performance. Ultimately, it has been concluded that asset diversification has a significant effect on financial performance in the Ethiopian commercial banking sector. Hence, a researcher suggests that banks need to optimize their asset diversification so as to realize maximum profit and minimize the cost of funds based on the result of the study.

Keywords: asset diversification, financial performance, role, commercial banks

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Authors: Janusz Getta, Zhaoxi Pan

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Performance-based quality evaluation of database conceptual schemas is an important aspect of database design process. It is evident that different conceptual schemas provide different logical schemas and performance of user applications strongly depends on logical and physical database structures. This work presents the entire process of performance-based quality evaluation of conceptual schemas. First, we show format. Then, the paper proposes a new specification of object algebra for representation of conceptual level database applications. Transformation of conceptual schemas and expression of object algebra into implementation schema and implementation in a particular database system allows for precise estimation of the processing costs of database applications and as a consequence for precise evaluation of performance-based quality of conceptual schemas. Then we describe an experiment as a proof of concept for the evaluation procedure presented in the paper.

Keywords: conceptual schema, implementation schema, logical schema, object algebra, performance evaluation, query processing

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Authors: Bulus Kpame, Mukhtar Mohammed Alhaji, Garba Jibril

Abstract:

In any team sport, the most important variables that should be used to measure performance are physical condition, and technical and tactical performance. In a complex game like football, it is extremely difficult to measure the relative importance of each of these variables. However, physical fitness itself has been shown to consist of several components, like endurance, strength, flexibility, agility, coordination and speed. Each of these components has been shown to consist of several subcomponents. This paper attempts to describe a test battery to assess and evaluate physical performance in football players. This battery comprises a functional, structured training session of about 2.5hrs. it consists of quality rating of the warm-up procedure, tests of flexibility, football skills, power, speed, and endurance. Acceptable values for performance in each of the tests are also presented under each test. It is hoped that this battery of tests will be helpful to the coach in determining the effect of a specific training program. It would also be helpful to train physician and trainer, to monitor progress during rehabilitation after sustaining any injury.

Keywords: assessment, evaluation, performance, programs

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Authors: Yared Pawlos Woldeyes

Abstract:

Public Relations often referred to as ‘PR’, is the practice of managing the spread of information between an individual or organization, such as a business, government agency, or a nonprofit organization, and the public. Public Relations are important because they help organizations or entities cultivate and maintain meaningful connections with society at large through platforms like print media and social media. Individuals that identify as public relation specialists establish and maintain relationships with an organization’s target audiences, relevant media sources, and opinion leaders. With regard to the challenges, when trying to practice public relations for government institutions, the priority for specialists is often to help members of society exercise a positive attitude and impression of a country’s political systems and practices. If you consider the case of public relations for government entities in Ethiopia there are several factors to consider. First, public relations in Ethiopia are very much driven by a desire to create a good image of the country and prevent the spread of any information that creates a bad image of Ethiopia. Also, the current ruling party dominates public relations in Ethiopia. Unfortunately, this means that more often than not, public relations specialists are forced by the government to spread and mass communicate false information to the public instead of the truth. Any opposition to government’s agenda will result in seriously negative repercussions for public relations specialists. Although public relations is supposed to create a positive and honest relationship between an organization or the government with the public, in Ethiopia, that is not the case. As a result, very few people express an interest in practicing public relations here. Despite this, there is an opportunity for the development of an accountable public relation affairs in developing nations, taking Ethiopian’s case. For instance, the fact that Public relations are provided as a field of study in college or university to produce competent and trained specialists, the enormous contribution of good communication to the public developmental efforts linking the government to the people, and the better payment to employees of public relation officers are some of them. Therefore, there is a need by the respective stakeholders to work in coalition in raising awareness of the youth regarding the importance of a responsible public relations officer to the country’s developmental efforts, encouragement of Civil Society Organizations working in promoting free press and expression of ideas, improving the governmental structure to be transparent and that allows independent officers, and hosting international conferences on public relations practice so that the specialists can exchange knowledge and skills.

Keywords: developing nations, Ethiopia, public relations, public relations specialist

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Authors: Mohamed Edokali, Robert Menzel, David Harbottle, Ali Hassanpour

Abstract:

Forward osmosis (FO) process has stood out as an energy-efficient technology for water desalination and purification, although the practical application of FO for desalination still relies on RO-based Thin Film Composite (TFC) and Cellulose Triacetate (CTA) polymeric membranes which have a low performance. Recently, graphene oxide (GO) laminated membranes have been considered an ideal selection to overcome the bottleneck of the FO-polymeric membranes owing to their simple fabrication procedures, controllable thickness and pore size and high water permeability rates. However, the low stability of GO laminates in wet and harsh environments is still problematic. The recent developments of modified GO and hydrophobic reduced graphene oxide (rGO) membranes for FO desalination have demonstrated attempts to overcome the ongoing trade-off between desalination performance and stability, which is yet to be achieved prior to the practical implementation. In this study, acid-functionalized GO nanosheets cooperatively reduced and crosslinked by the hyperbranched polyethyleneimine (PEI) and polyethylene glycol (PEG) polymers, respectively, are applied for fabrication of the FO membrane, to enhance the membrane stability and performance, and compared with other functionalized rGO-FO membranes. PEI/PEG doped rGO membrane retained two compacted d-spacings (0.7 and 0.31 nm) compared to the acid-functionalized GO membrane alone (0.82 nm). Besides increasing the hydrophilicity, the coating layer of PEG onto the PEI-doped rGO membrane surface enhanced the structural integrity of the membrane chemically and mechanically. As a result of these synergetic effects, the PEI/PEG doped rGO membrane exhibited a water permeation of 7.7 LMH, salt rejection of 97.9 %, and reverse solute flux of 0.506 gMH at low flow rates in the FO desalination process.

Keywords: desalination, forward osmosis, membrane performance, polyethyleneimine, polyethylene glycol, reduced graphene oxide, stability

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Authors: Narender Singh Thakur, Sunil Chamoli

Abstract:

The use of roughness geometry in the rectangular channel duct is an effective technique to enhance the rate of heat transfer to the working fluid. The present research concentrates on the performance comparison of a rectangular channel with different roughness geometry of the test plate. The performance enhancement is compared by considering the statistical correlations developed by the various investigators for Nusselt number and friction factor. Among all the investigated geometries multiple v-shaped rib roughened rectangular channel found thermo hydraulically better than other investigated geometries under similar current and operating conditions.

Keywords: nusselt number, friction factor, thermohydraulic, performance parameter

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Authors: Gayathri P. Nair

Abstract:

The focus of this study is to identify whether the board structure has any significant impact on the firm performance and finding out any evidence of being listed in the Fortune 500 list compiled and published by the American business magazine, Fortune and published globally by Time Inc., as the world’s wealthiest companies. The list has been released based on the ranking obtained for the total revenues for the respective fiscal year which has ended on or before March 31st. The study has been conducted on the Indian companies that were listed in the Fortune 500 list for the past 10 years. This study employs a logical regression between the variables, firm performance and board composition as mentioned in the clause 49 of companies act 1956 and 2013. For getting the firm performance, ROA has selected as the key performance metric, as it focuses the management attention on the assets required to run the business. The highlight of the study is that the tools had been applied between public and private sector firms so that, it reveals whether the board composition is helping out to maintain the position in the list. In addition, the findings reveal that apart from independent directors, all other variables have significant impact on firm performance.

Keywords: board structure, Fortune 500 company, firm performance, India

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Authors: Zulfiye Ahan, Mustafa Dogu, Elcin Yilmaz

Abstract:

The use of nonwoven textile materials in many application areas is rapidly increasing thanks to their versatile performance properties. The automotive industry is one of the largest sectors in the world with a potential market of more than 2 billion euros for nonwoven textile materials applications. Lightweight materials having higher mechanical performance, better sound and heat insulation properties are of interest in many applications. Since the usage of nonwoven surfaces provides many of these advantages, the demand for this kind of materials is gradually growing especially in the automotive industry. Nonwoven materials used in lightweight vehicles can contain economical and high strength thermoplastics as well as durable components such as glass fiber. By bringing these composite materials into foam structure containing micro or nanopores, products with high absorption ability, light and mechanically stronger can be fabricated. In this respect, our goal is to produce thermoplastic composite nonwoven by using nonwoven glass fiber fabric reinforced polypropylene (PP). Azodicarbonamide (ADC) was selected as a foaming agent and a thermal process was applied to obtain porous structure. Various foaming temperature ranges and residence times were studied to examine the foaming behaviour of the thermoplastic composite nonwoven. Physicochemical and mechanical tests were applied in order to analyze the characteristics of composite foams.

Keywords: composite nonwoven, thermoplastic foams, foaming agent, foaming behavior

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Authors: Samsher Gautam, Apoorva Roy, Bhuvan Aggarwal

Abstract:

Vapor absorption refrigeration systems can replace vapor compression systems in many applications as they can operate on a low-grade heat source and are environment-friendly. Widely used refrigerants such as CFCs and HFCs cause significant global warming. Natural refrigerants can be an alternative to them, among which carbon dioxide is promising for use in automotive air conditioning systems. Its inherent safety, ability to withstand high pressure and high heat transfer coefficient coupled with easy availability make it a likely choice for refrigerant. Various properties of the ionic liquid [bmim][PF₆], such as non-toxicity, stability over a wide temperature range and ability to dissolve gases like carbon dioxide, make it a suitable absorbent for a vapor absorption refrigeration system. In this paper, an absorption chiller consisting of a generator, condenser, evaporator and absorber was studied at an operating temperature of 70⁰C. A thermodynamic model was set up using the Peng-Robinson equations of state to predict the behavior of the refrigerant and absorbent pair at different points in the system. A MATLAB code was used to obtain the values of enthalpy and entropy at selected points in the system. The exergy destruction in each component and exergetic coefficient of performance (ECOP) of the system were calculated by performing an exergy analysis based on the second law of thermodynamics. Graphs were plotted between varying operating conditions and the ECOP obtained in each case. The effect of every component on the ECOP was examined. The exergetic coefficient of performance was found to be lesser than the coefficient of performance based on the first law of thermodynamics.

Keywords: [bmim][PF₆] as absorbent, carbon dioxide as refrigerant, exergy analysis, Peng-Robinson equations of state, vapor absorption refrigeration

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Authors: Radia Kamel

Abstract:

Considerable progress has been made in the development of bulk-heterojunction organic solar cells (OSCs) based on a blend of p-type and n-type organic semiconductors. To optimize the interfacial properties between the active layer and the electrode, a cathode buffer layer (CBL) is introduced. This layer can reduce the leakage current, increasing the open-circuit voltage and the fill factor while improving the OSC stability. In this work, the performance of PM6:Y6 OSC with 1-Chloronaphthalene as an additive is examined. To accomplish this, three CBLs PNDIT-F3N-Br, ZrAcac, and PDINO, are compared using the conventional configuration. The device with PNDIT-F3N-Br as CBL exhibits the highest power conversion efficiency of 16.04%. The results demonstrate that modifying the cathode buffer layer is crucial for achieving high-performance OSCs.

Keywords: bulk heterojunction, cathode buffer layer, efficiency, organic solar cells

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