Search results for: work load
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 15537

Search results for: work load

9957 Multimetallic and Multiferocenyl Assemblies of Ferocenyl-Based Dithiophospohonate and Their Electrochemical Properties

Authors: J. Tomilla Ajayi, Werner E. Van Zyl

Abstract:

This work presents an overview of the reaction of 2, 4-diferrocenyl-1, 3-dithiadiphosphetane-2, 4-disulfide (Ferrocenyl Lawesson’s reagent) with water to produce the non-symmetric, ferocenyl dithiophosphonic acid respectively in high yields. These acids were readily deprotonated by anhydrous Ammonia to yield the corresponding ammonium salt NH4S2PFcOH. These were complex to Ni (II) in molar ratio 1:1 and 1:2. The resulting complex from the reaction formed same compound with different isomers (Cis and Trans) and also compound with multimetallic coordination. Quality X-ray crystals were formed from THF/Ether. The compounds were characterized by 1H, 31P NMR, and FTIR. Bulk purity were confirmed by either ESI-MS or elemental analysis and The XRD images were obtained using single crystal X-ray crystallographic studies. The electrochemical investigation of the Compounds were carried out using cyclic voltammetry.

Keywords: ferrocenyl, dithiophosphonate, isomer, coordination

Procedia PDF Downloads 236
9956 The Design of the Questionnaire of Attitudes in Physics Teaching

Authors: Ricardo Merlo

Abstract:

Attitude is a hypothetical construct that can be significantly measured to know the favorable or unfavorable predisposition that students have towards the teaching of sciences such as Physics. Although the state-of-the-art attitude test used in Physics teaching indicated different design and validation models in different groups of students, the analysis of the weight given to each dimension that supported the attitude was scarcely evaluated. Then, in this work, a methodology of attitude questionnaire construction process was proposed that allowed the teacher to design and validate the measurement instrument for different subjects of Physics at the university level developed in the classroom according to the weight considered to the affective, knowledge, and behavioural dimensions. Finally, questionnaire models were tested for the case of incoming university students, achieving significant results in the improvement of Physics teaching.

Keywords: attitude, physics teaching, motivation, academic performance

Procedia PDF Downloads 51
9955 Bio-Electrochemical Process Coupled with MnO2 Nanowires for Wastewater Treatment

Authors: A. Giwa, S. M. Jung, W. Fang, J. Kong, S. W. Hasan

Abstract:

MnO2 nanowires were developed as filtration media for wastewater treatment that uniquely combines several advantages. The resulting material demonstrated strong capability to remove the pollution of heavy metal ions and organic contents in water. In addition, the manufacture process of such material is practical and economical. In this work, MnO2 nanowires were integrated with the state-of-art bio-electrochemical system for wastewater treatment, to overcome problems currently encountered with organic, inorganic, heavy metal, and microbe removal, and to minimize the unit footprint (land/space occupation) at low cost. Results showed that coupling the bio-electrochemical with MnO2 resulted in very encouraging results with higher removal efficiencies of such pollutants.

Keywords: bio-electrochemical, nanowires, novel, wastewater

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9954 Psychological Consultation of Married Couples at Various Stages of Formation of the Young Family

Authors: Gulden Aykinbaeva, Assem Umirzakova, Assel Makhadiyeva

Abstract:

The problem of studying of young married couples in connection with a change of social institute of a family and marriage is represented very actual for family consultation, considering a family role in the development of modern society. Results of numerous researchs say that one of difficult in formation and stabilization of a matrimony is the period of a young family. This period is characterized by various processes of integration, adaptation and emotional compatibility of spouses. The young family in it the period endures the first standard crisis which postpones a print for the further development of the family scenario. Emergence new, earlier not existing, systems of values render a huge value on the process of formation of a young family and each of spouses separately. Possibly to solve the set family tasks at the development of the uniform system of the family relations in which socially mature persons capable to consider a family as the creativity of each other act as subjects. Due to the research objective in work the following techniques were used: a questionnaire of satisfaction with V. V. Stolin's marriage and A. N. Volkova's technique directed on detection of coherence of family values and role installations in a married couple, and also content – the analysis. Development of an internal basis of a family on mutual clearing of values is important during the work with married couples. 'The mature view' of the partner in the marriage union provides coherence between the expected and real behavior of the partner that is important for the realization of the purposes of adaptation in a family. For research of communication of the data obtained by means of A. N. Volkova's techniques, V. V. Stolina and content – the analysis, the correlation analysis, with the application of the criterion of Spirmen was used. The analysis of results of the conducted research allowed us to determine the number of consistent patterns: 1. Nature of change of satisfaction with marriage at spouses testifies that the matrimonial relations undergo high-quality changes at different stages of formation of a young family. 2. The matrimonial relations in the course of their development, formation and functioning in young marriage undergo considerable changes on psychological, social and psychological and insignificant — at the psychophysiological and sociocultural levels. The material received by us allows to plan ways of further detailed researches of the development of the matrimonial relations not only in the young marriage but also at further stages of development of a matrimony. We believe that the results received in this research can be almost applied at creation of algorithms of selection of marriage partners, at diagnostics of character and the maintenance of matrimonial disharmonies, at the forecast of stability of marriage and a family.

Keywords: married couples, formation of the young family, psychological consultation, matrimony

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9953 Experimental Research of High Pressure Jet Interaction with Supersonic Crossflow

Authors: Bartosz Olszanski, Zbigniew Nosal, Jacek Rokicki

Abstract:

An experimental study of cold-jet (nitrogen) reaction control jet system has been carried out to investigate the flow control efficiency for low to moderate jet pressure ratios (total jet pressure p0jet over free stream static pressure in the wind tunnel p∞) and different angles of attack for infinite Mach number equal to 2. An investigation of jet influence was conducted on a flat plate geometry placed in the test section of intermittent supersonic wind tunnel of Department of Aerodynamics, WUT. Various convergent jet nozzle geometries to obtain different jet momentum ratios were tested on the same test model geometry. Surface static pressure measurements, Schlieren flow visualizations (using continuous and photoflash light source), load cell measurements gave insight into the supersonic crossflow interaction for different jet pressure and jet momentum ratios and their influence on the efficiency of side jet control as described by the amplification factor (actual to theoretical net force generated by the control nozzle). Moreover, the quasi-steady numerical simulations of flow through the same wind tunnel geometry (convergent-divergent nozzle plus test section) were performed using ANSYS Fluent basing on Reynolds-Averaged Navier-Stokes (RANS) solver incorporated with k-ω Shear Stress Transport (SST) turbulence model to assess the possible spurious influence of test section walls over the jet exit near field area of interest. The strong bow shock, barrel shock, and Mach disk as well as lambda separation region in front of nozzle were observed as images taken by high-speed camera examine the interaction of the jet and the free stream. In addition, the development of large-scale vortex structures (counter-rotating vortex pair) was detected. The history of complex static pressure pattern on the plate was recorded and compared to the force measurement data as well as numerical simulation data. The analysis of the obtained results, especially in the wake of the jet showed important features of the interaction mechanisms between the lateral jet and the flow field.

Keywords: flow visualization techniques, pressure measurements, reaction control jet, supersonic cross flow

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9952 A Qualitative Look at Mental Health Stressors in Response to COVID-19

Authors: Gabriel G. Gaft, Xayvinay Xiong, Amanda Sunday

Abstract:

The emergent pandemic from COVID-19 virus has forced people to adjust to major changes. These changes include all elements of family and work life and required people to engage in novel behaviors. For many people, the social norms to which they have been accustomed no longer prevail. Not surprisingly, such enormous changes in daily life have been associated with greater problems in mental health; and research regarding ways in which mental health professionals can support people is more necessary than ever before. It is often useful to assess people’s reactions through surveys and utilize quantitative data to answer questions about coping strategies etc. It is also likely, however, that a host of individual factors are going to contribute to what might be considered 'good' or 'bad' coping mechanisms to a worldwide pandemic. To this end, qualitative studies—where the individual’s subjective experience is highlighted—are likely to provide more vital information for mental health professionals interested in supporting the particular person in front of them. This study reports on qualitative data, where X participants were asked questions about social distancing, coping strategies, and general attitudes towards social changes resulting from the COVID-19 pandemic. Informal interviews were conducted during the months of June-July 2020. Data were analyzed using Interpretative Phenomenological Analyses. Themes were identified first for each participant and then compared across different individual participants. Several findings emerged. First, all participants understood major health messages being imparted by governing bodies such as the CDC and WHO. The researchers feel this finding is important as it suggests health messages are at least being effectively communicated. Second, there was a clear trend for themes which highlighted the conflicting emotions participants felt about the changes they were expected to endure: positive and negative elements were identified, although a participant who had pre-existing conditions placed greater emphasis on the negative elements. One participant who was particularly interested in impression management also exclusively emphasized negative emotions. Third, participants who were able to reevaluate priorities—what Lazarus might call secondary appraisals—experienced social distancing as a positive rather than negative phenomenon. Finally, participants who were able to develop specific strategies—such as boundaries for work and self-care—reported themes of adjustment and contentment. Taken together, these findings suggest mental health practitioners can assist people to adjust more positively through specific techniques focusing on re-evaluation of life priorities and strategic coping skills.

Keywords: COVID-19, pandemic, phenomenology, virus

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9951 Wellness Warriors: A Qualitative Exploration of Frontline Healthcare Staff Responding to Crisis

Authors: Andrea Knezevic, Padmini Pai, Julaine Allan, Katarzyna Olcoń, Louisa Smith

Abstract:

Healthcare staff are on the frontline during times of disaster and are required to support the health and wellbeing of communities despite any personal adversity and trauma they are experiencing as a result of the disaster. This study explored the experiences of healthcare staff trained as ‘Wellness Warriors’ following the 2019-2020 Australian bushfires. The findings indicated that healthcare staff developed interpersonal skills around deep listening and connecting with others which allowed them to feel differently about work and restored their faith in healthcare leadership.

Keywords: Australian bushfires, burnout, health care providers, mental health, occupational trauma, post-disaster, wellbeing, workplace wellness

Procedia PDF Downloads 113
9950 Switching of Series-Parallel Connected Modules in an Array for Partially Shaded Conditions in a Pollution Intensive Area Using High Powered MOSFETs

Authors: Osamede Asowata, Christo Pienaar, Johan Bekker

Abstract:

Photovoltaic (PV) modules may become a trend for future PV systems because of their greater flexibility in distributed system expansion, easier installation due to their nature, and higher system-level energy harnessing capabilities under shaded or PV manufacturing mismatch conditions. This is as compared to the single or multi-string inverters. Novel residential scale PV arrays are commonly connected to the grid by a single DC–AC inverter connected to a series, parallel or series-parallel string of PV panels, or many small DC–AC inverters which connect one or two panels directly to the AC grid. With an increasing worldwide interest in sustainable energy production and use, there is renewed focus on the power electronic converter interface for DC energy sources. Three specific examples of such DC energy sources that will have a role in distributed generation and sustainable energy systems are the photovoltaic (PV) panel, the fuel cell stack, and batteries of various chemistries. A high-efficiency inverter using Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs) for all active switches is presented for a non-isolated photovoltaic and AC-module applications. The proposed configuration features a high efficiency over a wide load range, low ground leakage current and low-output AC-current distortion with no need for split capacitors. The detailed power stage operating principles, pulse width modulation scheme, multilevel bootstrap power supply, and integrated gate drivers for the proposed inverter is described. Experimental results of a hardware prototype, show that not only are MOSFET efficient in the system, it also shows that the ground leakage current issues are alleviated in the proposed inverter and also a 98 % maximum associated driver circuit is achieved. This, in turn, provides the need for a possible photovoltaic panel switching technique. This will help to reduce the effect of cloud movements as well as improve the overall efficiency of the system.

Keywords: grid connected photovoltaic (PV), Matlab efficiency simulation, maximum power point tracking (MPPT), module integrated converters (MICs), multilevel converter, series connected converter

Procedia PDF Downloads 109
9949 Useful Lessons from the Success of Physics Outreach in Jamaica

Authors: M. J. Ponnambalam

Abstract:

Physics Outreach in Jamaica has nearly tripled the number of students doing Introductory Calculus-based Physics at the University of the West Indies (UWI, Mona) within 5 years, and thus has shown the importance of Physics Teaching & Learning in Informal Settings. In 1899, the first president of the American Physical Society called Physics, “the science above all sciences.” Sure enough, exactly one hundred years later, Time magazine proclaims Albert Einstein, “Person of the Century.” Unfortunately, Physics seems to be losing that glow in this century. Many countries, big and small, are finding it difficult to attract bright young minds to pursue Physics. At UWI, Mona, the number of students in first year Physics dropped to an all-time low of 81 in 2006, from more than 200 in the nineteen eighties, spelling disaster for the Physics Department! The author of this paper launched an aggressive Physics Outreach that same year, aimed at conveying to the students and the general public the following messages: i) Physics is an exciting intellectual enterprise, full of fun and delight. ii) Physics is very helpful in understanding how things like TV, CD player, car, computer, X-ray, CT scan, MRI, etc. work. iii) The critical and analytical thinking developed in the study of Physics is of inestimable value in almost any field. iv) Physics is the core subject for Science and Technology, and hence of national development. Science Literacy is a ‘must’ for any nation in the 21st century. Hence, the Physics Outreach aims at reaching out to every person, through every possible means. The Outreach work is split into the following target groups: i) Universities, ii) High Schools iii) Middle Schools, iv) Primary Schools, v) General Public, and vi) Physics teachers in High Schools. The programmes, tools and best practices are adjusted to suit each target group. The feedback from each group is highly positive. e.g. In February 2014, the author conducted in 3 Primary Schools the Interactive Show on ‘Science Is Fun’ to stimulate 290 students’ interest in Science – with lively and interesting demonstrations and experiments in a highly interactive way, using dramatization, story-telling and dancing. The feedback: 47% found the Show ‘Exciting’ and 51% found it ‘Interesting’ – totaling an impressive 98%. When asked to describe the Show in their own words, the leading 4 responses were: ‘Fun’ (26%), ‘Interesting’ (20%), ‘Exciting’ (14%) and ‘Educational’ (10%) – confirming that ‘fun’ & ‘education’ can go together. The success of Physics Outreach in Jamaica verifies the following words of Chodos, Associate Executive Officer of the American Physical Society: “If we could get members to go to K-12 schools and levitate a magnet or something, we really think these efforts would bring great rewards.”

Keywords: physics education, physics popularization, UWI, Jamaica

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9948 Double Fourier Series Applied to Supraharmonic Determination: The Specific Cases of a Boost and an Interleaved Boost Converter Used as Active Power Factor Correctors

Authors: Erzen Muharemi, Emmanuel De Jaeger, Jos Knockaert

Abstract:

The work presented here investigates the modeling of power electronics converters in terms of their harmonic production. Specifically, it addresses high-frequency emissions in the range of 2-150 kHz, referred to as supraharmonics. This paper models a conventional converter, namely the boost converter used as an active power factor corrector (APFC). Furthermore, the modeling is extended to the case of the interleaved boost converter, which offers advantages such as halving the emissions. Finally, a comparison between the theoretical, numerical, and experimental results will be provided.

Keywords: APFC, boost converter, converter modeling, double fourier series, supraharmonics

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9947 "If It Bleeds It Leads” the Visual Witnessing Trauma Phenomenon among Journalists: An Analysis of Various Media Images from East Africa

Authors: Lydia Ouma Radoli

Abstract:

The paradox of documenting history through visuals that objectify gruesome images to depict the prominence of stories intrigues media researchers. In East Africa, the topic has been captured in a variety of media frames, but scantly in scholarly work. This paper adopts Visual Rhetoric and Framing Theories to tease out the drivers behind the criteria for the selection of violent visuals. The paper projects that quantitative and qualitative literature regarding journalists’ personal and work-related exposure to PSTD will give insights into the concept of trauma journalism - reporting of horrific events, e.g., violent crime and terror. The data will be collected through methods such as document analysis (photographs and videos) and in-depth interviews to summarize the informational contents with respect to the research objectives and questions. The study is hinged on the background that the criterion for news production is constructed from the idea that ‘if there’s violence, conflict, and death involved, the story gets top priority.’ The anticipated outcome is to establish trauma experiences of visual rhetors, suggest mitigations, and address gaps in academic research. The findings of the study will sustain the critical role of visual rhetors. Further, media practitioners may find the study useful in assessing the effects and values of visual witnessing. Historically, the criterion for visual news production has been that if there’s violence, conflict, and death involved, the story gets top priority. To capture the goriness of the images, media theorists and sociologists have used the expression: “If it bleeds, it leads.” The statement assumes that audiences are attracted to pictures that show violent images. Further, research on visual aspects of Television news has shown its ability to hold viewers’ attention and cause aggression. This paper samples images and narratives from Journalists who have covered trauma-related events. The samples are indicative of the problem under study, which depicts journalists exposed to traumatic events as not receiving any Psycho-social support within newsrooms. It is hoped that the study could inform policy and practice within developing countries through the interpretations of theoretical and empirical explanations of existing trauma phenomena among journalists.

Keywords: visual-witnessing, media culture, visual rhetoric, imaging violence in East Africa

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9946 Downtime Estimation of Building Structures Using Fuzzy Logic

Authors: M. De Iuliis, O. Kammouh, G. P. Cimellaro, S. Tesfamariam

Abstract:

Community Resilience has gained a significant attention due to the recent unexpected natural and man-made disasters. Resilience is the process of maintaining livable conditions in the event of interruptions in normally available services. Estimating the resilience of systems, ranging from individuals to communities, is a formidable task due to the complexity involved in the process. The most challenging parameter involved in the resilience assessment is the 'downtime'. Downtime is the time needed for a system to recover its services following a disaster event. Estimating the exact downtime of a system requires a lot of inputs and resources that are not always obtainable. The uncertainties in the downtime estimation are usually handled using probabilistic methods, which necessitates acquiring large historical data. The estimation process also involves ignorance, imprecision, vagueness, and subjective judgment. In this paper, a fuzzy-based approach to estimate the downtime of building structures following earthquake events is proposed. Fuzzy logic can integrate descriptive (linguistic) knowledge and numerical data into the fuzzy system. This ability allows the use of walk down surveys, which collect data in a linguistic or a numerical form. The use of fuzzy logic permits a fast and economical estimation of parameters that involve uncertainties. The first step of the method is to determine the building’s vulnerability. A rapid visual screening is designed to acquire information about the analyzed building (e.g. year of construction, structural system, site seismicity, etc.). Then, a fuzzy logic is implemented using a hierarchical scheme to determine the building damageability, which is the main ingredient to estimate the downtime. Generally, the downtime can be divided into three main components: downtime due to the actual damage (DT1); downtime caused by rational and irrational delays (DT2); and downtime due to utilities disruption (DT3). In this work, DT1 is computed by relating the building damageability results obtained from the visual screening to some already-defined components repair times available in the literature. DT2 and DT3 are estimated using the REDITM Guidelines. The Downtime of the building is finally obtained by combining the three components. The proposed method also allows identifying the downtime corresponding to each of the three recovery states: re-occupancy; functional recovery; and full recovery. Future work is aimed at improving the current methodology to pass from the downtime to the resilience of buildings. This will provide a simple tool that can be used by the authorities for decision making.

Keywords: resilience, restoration, downtime, community resilience, fuzzy logic, recovery, damage, built environment

Procedia PDF Downloads 152
9945 Flow Behavior and Performances of Centrifugal Compressor Stage Vaneless Diffusers

Authors: Y.Galerkin, O. Solovieva

Abstract:

Flow parameters are calculated in vaneless diffusers with relative width 0,014 – 0,10 constant along radii. Inlet flow angles and similarity criteria were varied. Information about flow structure is presented – meridian streamlines configuration, information on flow full development, flow separation. Polytrophic efficiency, loss and recovery coefficient are used to compare diffusers’ effectiveness. The sample of narrow diffuser optimization by conical walls application is presented. Three tampered variants of a wide diffuser are compared too. The work is made in the R&D laboratory “Gas dynamics of turbo machines” of the TU SPb.

Keywords: vaneless diffuser, relative width, flow angle, flow separation, loss coefficient, similarity criteria

Procedia PDF Downloads 478
9944 Improving the Quality of Transport Management Services with Fuzzy Signatures

Authors: Csaba I. Hencz, István Á. Harmati

Abstract:

Nowadays the significance of road transport is gradually increasing. All transport companies are working in the same external environment where the speed of transport is defined by traffic rules. The main objective is to accelerate the speed of service and it is only dependent on the individual abilities of the managing members. These operational control units make decisions quickly (in a typically experiential and/or intuitive way). For this reason, support for these decisions is an important task. Our goal is to create a decision support model based on fuzzy signatures that can assist the work of operational management automatically. If the model sets parameters properly, the management of transport could be more economical and efficient.

Keywords: freight transport, decision support, information handling, fuzzy methods

Procedia PDF Downloads 243
9943 Kinematic Modelling and Task-Based Synthesis of a Passive Architecture for an Upper Limb Rehabilitation Exoskeleton

Authors: Sakshi Gupta, Anupam Agrawal, Ekta Singla

Abstract:

An exoskeleton design for rehabilitation purpose encounters many challenges, including ergonomically acceptable wearing technology, architectural design human-motion compatibility, actuation type, human-robot interaction, etc. In this paper, a passive architecture for upper limb exoskeleton is proposed for assisting in rehabilitation tasks. Kinematic modelling is detailed for task-based kinematic synthesis of the wearable exoskeleton for self-feeding tasks. The exoskeleton architecture possesses expansion and torsional springs which are able to store and redistribute energy over the human arm joints. The elastic characteristics of the springs have been optimized to minimize the mechanical work of the human arm joints. The concept of hybrid combination of a 4-bar parallelogram linkage and a serial linkage were chosen, where the 4-bar parallelogram linkage with expansion spring acts as a rigid structure which is used to provide the rotational degree-of-freedom (DOF) required for lowering and raising of the arm. The single linkage with torsional spring allows for the rotational DOF required for elbow movement. The focus of the paper is kinematic modelling, analysis and task-based synthesis framework for the proposed architecture, keeping in considerations the essential tasks of self-feeding and self-exercising during rehabilitation of partially healthy person. Rehabilitation of primary functional movements (activities of daily life, i.e., ADL) is routine activities that people tend to every day such as cleaning, dressing, feeding. We are focusing on the feeding process to make people independent in respect of the feeding tasks. The tasks are focused to post-surgery patients under rehabilitation with less than 40% weakness. The challenges addressed in work are ensuring to emulate the natural movement of the human arm. Human motion data is extracted through motion-sensors for targeted tasks of feeding and specific exercises. Task-based synthesis procedure framework will be discussed for the proposed architecture. The results include the simulation of the architectural concept for tracking the human-arm movements while displaying the kinematic and static study parameters for standard human weight. D-H parameters are used for kinematic modelling of the hybrid-mechanism, and the model is used while performing task-based optimal synthesis utilizing evolutionary algorithm.

Keywords: passive mechanism, task-based synthesis, emulating human-motion, exoskeleton

Procedia PDF Downloads 125
9942 Conformational Switch of hRAGE upon Self-Association

Authors: Ikhlas Ahmed, Jamillah Zamoon

Abstract:

The human receptor for advanced glycation end product is a plasma membrane receptor with an intrinsically disordered region. The protein consists of three extracellular domains, a single membrane spanning transmembrane domain, and a cytosolic domain which is intrinsically disordered and responsible for signaling. The disordered nature of the cytosolic domain allows it to be dynamic in solution. This receptor self-associates to higher forms. The association is triggered by ligand, metal or by the extracellular domain. Fluorescence spectroscopy technique is used to test the self-association of the different concentrations of the cytosolic domain. This work has concluded that the cytosolic domain of this receptor also self-associates. Moreover, the self-association does not require ligand or metal.

Keywords: fluorescence spectroscopy, hRAGE, IDP, Self-association

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9941 Analysis, Design, and Implementation of Quality Management System for KSA Software Company

Authors: Omar Said Almushyt

Abstract:

Quality management, in all countries all over the world, has become recently necessary to face challenges among companies. Software companies in KSA suffer from two problems, namely, low customer satisfaction, and low product quality. Implementation of quality management for a software company can solve these problems, by improving the quality of products and enhancing customer satisfaction. This will lead the company to be competitive. Introducing quality management system onto system analysis followed by system design and finally implementing that system can achieve these goals. Results of the present work showed that the proposed method can increase both the product quality by 10 % and the customer satisfaction by 20 %.

Keywords: quality, management, software, information engineering

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9940 Dynamic Wetting and Solidification

Authors: Yulii D. Shikhmurzaev

Abstract:

The modelling of the non-isothermal free-surface flows coupled with the solidification process has become the topic of intensive research with the advent of additive manufacturing, where complex 3-dimensional structures are produced by successive deposition and solidification of microscopic droplets of different materials. The issue is that both the spreading of liquids over solids and the propagation of the solidification front into the fluid and along the solid substrate pose fundamental difficulties for their mathematical modelling. The first of these processes, known as ‘dynamic wetting’, leads to the well-known ‘moving contact-line problem’ where, as shown recently both experimentally and theoretically, the contact angle formed by the free surfac with the solid substrate is not a function of the contact-line speed but is rather a functional of the flow field. The modelling of the propagating solidification front requires generalization of the classical Stefan problem, which would be able to describe the onset of the process and the non-equilibrium regime of solidification. Furthermore, given that both dynamic wetting and solification occur concurrently and interactively, they should be described within the same conceptual framework. The present work addresses this formidable problem and presents a mathematical model capable of describing the key element of additive manufacturing in a self-consistent and singularity-free way. The model is illustrated simple examples highlighting its main features. The main idea of the work is that both dynamic wetting and solidification, as well as some other fluid flows, are particular cases in a general class of flows where interfaces form and/or disappear. This conceptual framework allows one to derive a mathematical model from first principles using the methods of irreversible thermodynamics. Crucially, the interfaces are not considered as zero-mass entities introduced using Gibbsian ‘dividing surface’ but the 2-dimensional surface phases produced by the continuum limit in which the thickness of what physically is an interfacial layer vanishes, and its properties are characterized by ‘surface’ parameters (surface tension, surface density, etc). This approach allows for the mass exchange between the surface and bulk phases, which is the essence of the interface formation. As shown numerically, the onset of solidification is preceded by the pure interface formation stage, whilst the Stefan regime is the final stage where the temperature at the solidification front asymptotically approaches the solidification temperature. The developed model can also be applied to the flow with the substrate melting as well as a complex flow where both types of phase transition take place.

Keywords: dynamic wetting, interface formation, phase transition, solidification

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9939 Hierarchical Checkpoint Protocol in Data Grids

Authors: Rahma Souli-Jbali, Minyar Sassi Hidri, Rahma Ben Ayed

Abstract:

Grid of computing nodes has emerged as a representative means of connecting distributed computers or resources scattered all over the world for the purpose of computing and distributed storage. Since fault tolerance becomes complex due to the availability of resources in decentralized grid environment, it can be used in connection with replication in data grids. The objective of our work is to present fault tolerance in data grids with data replication-driven model based on clustering. The performance of the protocol is evaluated with Omnet++ simulator. The computational results show the efficiency of our protocol in terms of recovery time and the number of process in rollbacks.

Keywords: data grids, fault tolerance, clustering, chandy-lamport

Procedia PDF Downloads 318
9938 Wisdom Can Be the Expression of the Self

Authors: Jaypraksh Show, Pooja Rawat

Abstract:

Experiences are the fundamental aspects of understanding of ourslves and the world around, leading to wisdom. In the path of wisdom, explorative reflection is the process through which we integrate our experiences, weave them into autobiographical narratives. Further, Neisser, a psychologist, and philosopher, thinks ‘ourselves’ is the wide web of different concepts which help us to understand the world, he called it the conceptual self. The conceptual self, as the storehouse of experiences and different concepts, develops a wiser individual narrative. Thus, Wisdom can be conceived as the expression of the Self. Drawing from this, the current work explores the autobiographies of young adults, focusing on their narrative self and foundations of wisdom through narrative analysis. Using the corresponding interview data, we will shed light on the way they exploratively reflect on challenging situations and use their narrative experiences and conceptual understanding. The aim of this study is to understand the ‘conceptual wiser-self’.

Keywords: wisdom, self, conceptual self, narrative self, autobiography, narrative analysis

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9937 The Effects of SMS on the Formal Writings of the Students: A Comparative Study among the Students of Different Departments of IUB

Authors: Sumaira Saleem

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This study reveals that the use of SMS effect the formal writing of the students. SMS is in vogue sine the last decade but its detrimental effects are effecting not only to the set norms but also deviant forms of expressions have come into the community to which all are not acquainted and it creates a hurdle in effective communication. It also determines the reasons behind the usage of SMS practices in the formal writings like in assignments and examinations. For this study a questionnaire was designed for faculty and students the data was collected from The Islamia University Bahawalpur and the formal work of the students was also collected to check the manifestation of SMS practices in writings. Data was analysed on excel sheet and the tables and graphs are used to explain the ratios and percentages of SMS usage. The results show that the usage of SMS has very strong effect upon the students writing.

Keywords: technology, writing, effects, SMS

Procedia PDF Downloads 364
9936 A Conceptual Analysis of Teams’ Climate Role in the Intrapreneurial Process

Authors: Georgia C. Kosta, Christos S. Nicolaidis

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The present paper discusses the role of teams’ climate in the intrapreneurial process. Intrapreneurship, which corresponds for entrepreneurship in existing organizations, puts special emphasis on climate as an influential factor of the intrapreneurial behavior. Although climate exists at every level and in every subgroup of the organizational structure, research focuses mainly on the study of climate that characterizes organization as a whole. However, the climate of a work team may differ radically from the organizational climate, and in fact it can be far more influential. The paper provides a conceptual analysis of organizational climate from the intrapreneurial point of view, and sheds light upon teams’ climate role in the intrapreneurial posture.

Keywords: entrepreneurship, innovation, intrapreneurship, organizational climate, teams’ climate

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9935 S-S Coupling of Thiols to Disulfides Using Ionic Liquid in the Presence of Free Nano Fe2O3 Catalyst

Authors: Askar Sabet, Abdolrasoul Fakhraee, Motahahre Ramezanpour, Noorallah Alipour

Abstract:

An efficient and green method for oxidation of thiols to the corresponding disulfides is reported using ionic liquid [HSO3N(C2H4OSO3H)3] in the presence of free nano-Fe2O3 at 60°C. Ionic liquid is selective oxidant for S-S Coupling variety aliphatic and aromatic of thiols to corresponding disulfide in the presence of free nano-Fe2O3 as recoverable catalyst. Reaction has been performed in methanol as an inexpensive solvent. This reaction is clean and easy work-up with no side reaction.

Keywords: thiol, disulfide, ionic liquid, free nano-Fe2O3, oxidation, coupling

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9934 Software Cloning and Agile Environment

Authors: Ravi Kumar, Dhrubajit Barman, Nomi Baruah

Abstract:

Software Cloning has grown an active area in software engineering research community yielding numerous techniques, various tools and other methods for clone detection and removal. The copying, modifying a block of code is identified as cloning as it is the most basic means of software reuse. Agile Software Development is an approach which is currently being used in various software projects, so that it helps to respond the unpredictability of building software through incremental, iterative, work cadences. Software Cloning has been introduced to Agile Environment and many Agile Software Development approaches are using the concept of Software Cloning. This paper discusses the various Agile Software Development approaches. It also discusses the degree to which the Software Cloning concept is being introduced in the Agile Software Development approaches.

Keywords: agile environment, refactoring, reuse, software cloning

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9933 Uranium Adsorption Using a Composite Material Based on Platelet SBA-15 Supported Tin Salt Tungstomolybdophosphoric Acid

Authors: H. Aghayan, F. A. Hashemi, R. Yavari, S. Zolghadri

Abstract:

In this work, a new composite adsorbent based on a mesoporous silica SBA-15 with platelet morphology and tin salt of tungstomolybdophosphoric (TWMP) acid was synthesized and applied for uranium adsorption from aqueous solution. The sample was characterized by X-ray diffraction, Fourier transfer infra-red, and N2 adsorption-desorption analysis, and then, effect of various parameters such as concentration of metal ions and contact time on adsorption behavior was examined. The experimental result showed that the adsorption process was explained by the Langmuir isotherm model very well, and predominant reaction mechanism is physisorption. Kinetic data of adsorption suggest that the adsorption process can be described by the pseudo second-order reaction rate model.

Keywords: platelet SBA-15, tungstomolybdophosphoric acid, adsorption, uranium ion

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9932 ICTs Knowledge as a Way of Enhancing Literacy and Lifelong Learning in Nigeria

Authors: Jame O. Ezema, Odenigbo Veronica

Abstract:

The study covers the topic Information Communication and Technology (ICTs) knowledge as a way of enhancing Literacy and Lifelong learning in Nigeria. This work delved into defining of ICTs. Types of ICTs and media technologies were also mentioned. It further explained how ICTs can be strengthened and the uses of ICTs in education was duly emphasized. The paper also enumerated some side effects of ICTs on learners while the role of ICTs in enhancing literacy was explained. The study carried out strategies to use ICTs meaningfully in Literacy Programs and also emphasized the word lifelong learning in Nigeria. Some recommendations were made towards acquiring ICTs knowledge, so as to enhance Literacy and Lifelong learning in Nigeria.

Keywords: literacy, distance-learning, life-long learning for sustainable development, e-learning

Procedia PDF Downloads 485
9931 Grid Computing for Multi-Objective Optimization Problems

Authors: Aouaouche Elmaouhab, Hassina Beggar

Abstract:

Solving multi-objective discrete optimization applications has always been limited by the resources of one machine: By computing power or by memory, most often both. To speed up the calculations, the grid computing represents a primary solution for the treatment of these applications through the parallelization of these resolution methods. In this work, we are interested in the study of some methods for solving multiple objective integer linear programming problem based on Branch-and-Bound and the study of grid computing technology. This study allowed us to propose an implementation of the method of Abbas and Al on the grid by reducing the execution time. To enhance our contribution, the main results are presented.

Keywords: multi-objective optimization, integer linear programming, grid computing, parallel computing

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9930 Effect of Long-Term Boron Exposure on Liver Structure of Adult Male Albino Rats and a Possible Role of Vitamin C

Authors: Ola Abdel-Tawab Hussein

Abstract:

Background: Boron is a naturally occurring agent and an essential trace element of human, animals and higher plants. It is released in the form of boric acid (BA) that is water soluble and biolologically available. Its largest uses are in glass, detergents, agriculture, leather tanning industries, cosmetics, photographic materials, soaps and cleaners. Human consume daily few milligrams in the water, fruits and vegetables. High doses of boron had been recorded to be developmental and reproductive toxin in animals(Only few studies on human had investigated the health effects associated with exposure to boron. Vitamin C is a major water soluble non-enzymatic antioxidant, acts to overcome the oxidative stress. Aim of the work: However , the liver is exposed to toxic substances that are absorbed, degraded or conjugated there were little information exists about the effects of boron that it would specifically have in the liver tissue of experimental rats. So the present work aimed to study the effects of long-term boron ingestion on histological structural of the liver of adult male albino rats and to evaluate the protective role of vitamin C against induced changes. Material and Methods: 30 adult male albino rats were divided into 3 equal groups; Group I: control, Group II: recieved drinking water containing 55x10-6 gm boron/liter for 90 days and Group III: recieved vitamin C (200mg/Kg.B.W) orally concomitant with boron for the same period. liver specimens were processed for light and electron microscopic(TEM) study. Results: Examination of the liver sections of group II revealed foci of severe dilatation and congestion of central and portal veins with mononuclear cellular infiltration and hepatocellular vacuolation. Increased collagen deposition specially around the portal areas. Marked electrolucent areas in the cytoplasm, heterochromatic nuclei and destroyed organelles of the hepatocytes. Apoptotic cells were observed and decreased lipid content of ito cells. In Group III the co administration of vitamin C improved most of the structural changes of the hepatocytes, Ito cells, increased binucleated cells and decreased collagen fibers deposition. Conclusion: Thus, the long term exposure to boron, induced histological changes on the structure of liver. The co administration of vitamin C improved most of these structural changes.

Keywords: boron, liver, vitamin C, rats

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9929 Chloride Transport in Ultra High Performance Concrete

Authors: Radka Pernicova

Abstract:

Chloride resistance in Ultra High Performance Concrete (UHPC) is determined in this paper. This work deals with the one dimension chloride transport, which can be potentially dangerous particularly for the durability of concrete structures. Risk of reinforcement corrosion due to exposure to the concrete surface to direct the action of chloride ions (mainly in the form de-icing salts or groundwater) is dangerously increases. The measured data are investigated depending on the depth of penetration of chloride ions into the concrete structure. Comparative measurements with normal strength concrete are done as well. The experimental results showed that UHCP have improved resistance of chlorides penetration than NSC and also chloride diffusion depth is significantly lower in UHCP.

Keywords: chloride, one dimensional diffusion, transport, salinity, UHPC

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9928 Investigation of Main Operating Parameters Affecting Gas Turbine Efficiency and Gas Releases

Authors: Farhat Hajer, Khir Tahar, Ammar Ben Brahim

Abstract:

This work presents a study on the influence of the main operating variables on the gas turbine cycle. A numerical simulation of a gas turbine cycle is performed for a real net power of 100 MW. A calculation code is developed using EES software. The operating variables are taken in conformity with the local environmental conditions adopted by the Tunisian Society of Electricity and Gas. Results show that the increase of ambient temperature leads to an increase of Tpz and NOx emissions rate and a decrease of cycle efficiency and UHC emissions. The CO emissions decrease with the raise of residence time, while NOx emissions rate increases and UHC emissions rate decreases. Furthermore, both of cycle efficiency and NOx emissions increase with the increase of the pressure ratio.

Keywords: Carbon monoxide, Efficiency, Emissions, Gas Turbine, Nox, UHC

Procedia PDF Downloads 416