Search results for: cement type
1373 Development and Range Testing of a LoRaWAN System in an Urban Environment
Authors: N. R. Harris, J. Curry
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This paper describes the construction and operation of an experimental LoRaWAN network surrounding the University of Southampton in the United Kingdom. Following successful installation, an experimental node design is built and characterised, with particular emphasis on radio range. Several configurations are investigated, including different data rates, and varying heights of node. It is concluded that although range can be great (over 8 km in this case), environmental topology is critical. However, shorter range implementations, up to about 2 km in an urban environment, are relatively insensitive although care is still needed. The example node and the relatively simple base station reported demonstrate that LoraWan can be a very low cost and practical solution to Internet of Things type applications for distributed monitoring systems with sensors spread over distances of several km.Keywords: Wireless sensor network, LoRa, internet of things, propagation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15241372 Determining a Suitable Maintenance Measure for Gentelligent Components Using Case-Based Reasoning
Authors: M. Winkens, P. Nyhuis
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Components with sensory properties such as gentelligent components developed at the Collaborative Research Centre 653 offer a new angle in terms of the full utilization of the remaining service life as well as preventive maintenance. The developed methodology of component status driven maintenance analyzes the stress data obtained during the component's useful life and on the basis of this knowledge assesses the type of maintenance required in this case. The procedure is derived from the case-based reasoning method and will be explained in detail. The method's functionality is demonstrated with real-life data obtained during test runs of a racing car prototype.
Keywords: Gentelligent Components, Preventive Maintenance, Case based Reasoning.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19051371 Broadening of Raw Materials in the Steel Industry, by Recycling and Recovery Wastes
Authors: A. Todorut, T. Heput
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In technological processes, in addition to the main product, result a large amount of materials, called wastes, but due to the possibilities of recovery, by means of recycling and reusing it can fit in the category of by-products. These large amounts of dust from the steel industry are a major problem in terms of environmental and human health, landscape, etc. Solving these problems, the impressive amounts of waste can be done through their proper management and recovery for every type of waste. In this article it was watched the capitalizing through pelleting and briquetting of small and powdery waste aiming to obtain the sponge iron as raw material, used in blast furnaces and electric arc furnaces. The data have been processed in the Excel spreadsheet program, being presented in the form of diagrams.Keywords: Agglomeration, industry, iron, pellets, wastes.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15461370 Mechanical Behavior of Sandwiches with Various Glass Fiber/Epoxy Skins under Bending Load
Authors: Emre Kara, Metehan Demir, Şura Karakuzu, Kadir Koç, Ahmet F. Geylan, Halil Aykul
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While the polymeric foam cored sandwiches have been realized for many years, recently there is a growing and outstanding interest on the use of sandwiches consisting of aluminum foam core because of their some of the distinct mechanical properties such as high bending stiffness, high load carrying and energy absorption capacities. These properties make them very useful in the transportation industry (automotive, aerospace, shipbuilding industry), where the "lightweight design" philosophy and the safety of vehicles are very important aspects. Therefore, in this study, the sandwich panels with aluminum alloy foam core and various types and thicknesses of glass fiber reinforced polymer (GFRP) skins produced via Vacuum Assisted Resin Transfer Molding (VARTM) technique were obtained by using a commercial toughened epoxy based adhesive with two components. The aim of this contribution was the analysis of the bending response of sandwiches with various glass fiber reinforced polymer skins. The three point bending tests were performed on sandwich panels at different values of support span distance using a universal static testing machine in order to clarify the effects of the type and thickness of the GFRP skins in terms of peak load, energy efficiency and absorbed energy values. The GFRP skins were easily bonded to the aluminum alloy foam core under press machine with a very low pressure. The main results of the bending tests are: force-displacement curves, peak force values, absorbed energy, collapse mechanisms and the influence of the support span length and GFRP skins. The obtained results of the experimental investigation presented that the sandwich with the skin made of thicker S-Glass fabric failed at the highest load and absorbed the highest amount of energy compared to the other sandwich specimens. The increment of the support span distance made the decrease of the peak force and absorbed energy values for each type of panels. The common collapse mechanism of the panels was obtained as core shear failure which was not affected by the skin materials and the support span distance.
Keywords: Aluminum foam, collapse mechanisms, light-weight structures, transport application
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12161369 Cloud Computing Initiative using Modified Ant Colony Framework
Authors: Soumya Banerjee, Indrajit Mukherjee, P.K. Mahanti
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Scheduling of diversified service requests in distributed computing is a critical design issue. Cloud is a type of parallel and distributed system consisting of a collection of interconnected and virtual computers. It is not only the clusters and grid but also it comprises of next generation data centers. The paper proposes an initial heuristic algorithm to apply modified ant colony optimization approach for the diversified service allocation and scheduling mechanism in cloud paradigm. The proposed optimization method is aimed to minimize the scheduling throughput to service all the diversified requests according to the different resource allocator available under cloud computing environment.Keywords: Ant Colony, Cloud Computing, Grid, Resource allocator, Service Request.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27681368 High Energy Dual-Wavelength Mid-Infrared Extracavity KTA Optical Parametric Oscillator
Authors: Hongjun Liu, Qibing Sun, Nan Huang, Shaolan Zhu, Wei Zhao
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A high energy dual-wavelength extracavity KTA optical parametric oscillator (OPO) with excellent stability and beam quality, which is pumped by a Q-switched single-longitudinal-mode Nd:YAG laser, has been demonstrated based on a type II noncritical phase matching (NCPM) KTA crystal. The maximum pulse energy of 10.2 mJ with the output stability of better than 4.1% rms at 3.467 μm is obtained at the repetition rate of 10 Hz and pulse width of 2 ns, and the 11.9 mJ of 1.535 μm radiation is obtained simultaneously. This extracavity NCPM KTA OPO is very useful when high energy, high beam quality and smooth time domain are needed.Keywords: mid-infrared laser, OPO, dual-wavelength laser
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20711367 Slip Limit Prediction of High-Strength Bolt Joints Based on Local Approach
Authors: Chang He, Hiroshi Tamura, Hiroshi Katsuchi, Jiaqi Wang
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In this study, the aim is to infer the slip limit (static friction limit) of contact interfaces in bolt friction joints by analyzing other bolt friction joints with the same contact surface but in a different shape. By using the Weibull distribution to deal with microelements on the contact surface statistically, the slip limit of a certain type of bolt joint was predicted from other types of bolt joint with the same contact surface. As a result, this research succeeded in predicting the slip limit of bolt joins with different numbers of contact surfaces and with different numbers of bolt rows.
Keywords: Bolt joints, slip coefficient, finite element method, Weibull distribution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3221366 Features of the Immune Response in Mice were Immunized with Polio Vaccine in Combination with Chitosan Preparations as Adjuvants
Authors: Nelly К. Akhmatova, Оlga V. Lebedinskaya, Stanislav G. Markushin, Elvin А. Akhmatov, Lidiya A. Geiderova, Еlena А. Lebedinskaya, Vera M. Axenova, Аnatoliy P. Godovalov
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The study of cytokine expression in mice under the influence of inactivated poliovirus and Imovaks polio vaccine in combination with derivatives of chitosan shows various kinds of processes. There is a significant increase in IL-12 in the serum of immunized animals, which should stimulate the production of IFN-γ NK-cells and T-cells and polarize the immune response to Th1 type. Thus, the derivatives of chitosan can promote cell component of the immune response, providing a full antiviral immunity.Keywords: Poliovirus, chitosan, cytokine expression, antiviral immunity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19781365 Performance of an Electrocoagulation Process in Treating Direct Dye: Batch and Continuous Upflow Processes
Authors: C. Phalakornkule, S. Polgumhang, W. Tongdaung
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This study presents an investigation of electrochemical variables and an application of the optimal parameters in operating a continuous upflow electrocoagulation reactor in removing dye. Direct red 23, which is azo-based, was used as a representative of direct dyes. First, a batch mode was employed to optimize the design parameters: electrode type, electrode distance, current density and electrocoagulation time. The optimal parameters were found to be iron anode, distance between electrodes of 8 mm and current density of 30 A·m-2 with contact time of 5 min. The performance of the continuous upflow reactor with these parameters was satisfactory, with >95% color removal and energy consumption in the order of 0.6-0.7 kWh·m-3.Keywords: Decolorization, Direct Dye, Electrocoagulation, Textile Wastewater, Upflow Reactor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30421364 A New Analytic Solution for the Heat Conduction with Time-Dependent Heat Transfer Coefficient
Authors: Te Wen Tu, Sen Yung Lee
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An alternative approach is proposed to develop the analytic solution for one dimensional heat conduction with one mixed type boundary condition and general time-dependent heat transfer coefficient. In this study, the physic meaning of the solution procedure is revealed. It is shown that the shifting function takes the physic meaning of the reciprocal of Biot function in the initial time. Numerical results show the accuracy of this study. Comparing with those given in the existing literature, the difference is less than 0.3%.
Keywords: Analytic solution, heat transfer coefficient, shifting function method, time-dependent boundary condition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30121363 Modelling of a Stress-Strain State of Screws of Transpedicular Spine Fixation System
Authors: Oleksandr Poliakov, Genadiy Olinichenko, Yevgen Pashkov, Vadym Kramar, Mykhaylo Kalinin
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For maintenance of a spine stability during the postoperative period a transpedicular fixing of its elements is often used. Usually the transpedicular systems are formed of rods which as a result form a design of the frame type, fastening by screws to vertebras. Such design should be rigid and perceive loadings operating from the spine without essential deformations. From the perfection point of view of known designs their stress whole, and each of elements, in particular is of interest. In this study the modeling of the transpedicular screw is performed and estimation of its deformations taking into account interaction with a vertebra body having variable structure is made.Keywords: Spine, screw, stress-strain state, transpedicular fixation system, vertebra
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15241362 Robust Variogram Fitting Using Non-Linear Rank-Based Estimators
Authors: Hazem M. Al-Mofleh, John E. Daniels, Joseph W. McKean
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In this paper numerous robust fitting procedures are considered in estimating spatial variograms. In spatial statistics, the conventional variogram fitting procedure (non-linear weighted least squares) suffers from the same outlier problem that has plagued this method from its inception. Even a 3-parameter model, like the variogram, can be adversely affected by a single outlier. This paper uses the Hogg-Type adaptive procedures to select an optimal score function for a rank-based estimator for these non-linear models. Numeric examples and simulation studies will demonstrate the robustness, utility, efficiency, and validity of these estimates.
Keywords: Asymptotic relative efficiency, non-linear rank-based, robust, rank estimates, variogram.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15851361 Effect of Heat Treatment on the Phase Formation of La0.6Sr0.4CoO3-α
Authors: A. A. Samat, N. A. Abdullah, M. A. M. Ishak, N. Osman
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Powder of La0.6Sr0.4CoO3-α (LSCO) was synthesized by a combined citrate-EDTA method. The as-synthesized LSCO powder was calcined, respectively at temperatures of 800, 900 and 1000 °C with different heating/cooling rates which are 2, 5, 10 and 15 °C min-1. The effects of heat treatments on the phase formation of perovskite phase of LSCO were investigated by powder X-ray diffraction (XRD). The XRD patterns revealed that the rate of 5 °C min-1 is the optimum heating/cooling rate to obtain a single perovskite phase of LSCO with calcination temperature of 800 °C. This result was confirmed by a thermogravimetric analysis (TGA) as it showed a complete decomposition of intermediate compounds to form oxide material was also observed at 800 °C.Keywords: La0.6Sr0.4CoO3-α, heat treatment, perovskite-type oxide, XRD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 44041360 An Experimental Helicopter Wind Envelope for Ship Operations
Authors: R. Bardera Mora
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Launch and recovery helicopter wind envelope for a ship type was determined as the first step to the helicopter qualification program. Flight deck velocities data were obtained by means of a two components laser Doppler anemometer testing a 1/50th model in the wind tunnel stream. Full-scale flight deck measurements were obtained on board the ship using a sonic anemometer. Wind tunnel and full-scale measurements were compared, showing good agreement and finally, a preliminary launch and recovery helicopter wind envelope for this specific ship was built.Keywords: Flight deck flow, relative wind, ship airwake, wind envelope
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32491359 A Novel Approach to Fault Classification and Fault Location for Medium Voltage Cables Based on Artificial Neural Network
Authors: H. Khorashadi-Zadeh, M. R. Aghaebrahimi
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A novel application of neural network approach to fault classification and fault location of Medium voltage cables is demonstrated in this paper. Different faults on a protected cable should be classified and located correctly. This paper presents the use of neural networks as a pattern classifier algorithm to perform these tasks. The proposed scheme is insensitive to variation of different parameters such as fault type, fault resistance, and fault inception angle. Studies show that the proposed technique is able to offer high accuracy in both of the fault classification and fault location tasks.Keywords: Artificial neural networks, cable, fault location andfault classification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18511358 The Use of a Tactical Simulator as a Learning Resource at the Norwegian Military Academy
Authors: O. Boe, A. Langaard Jensen
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The Norwegian Military Academy (Army) has been using a tactical simulator for the last two years. During this time there has been some discussion concerning how to use the simulator most efficiently and what type of learning one achieves by using the simulator. The problem that is addressed in this paper is how simulators can be used as a learning resource for students concerned with developing their military profession. The aim of this article is to create a wider consciousness regarding the use of a simulator while educating officers in a military profession. The article discusses the use of simulators from two different perspectives. The first perspective deals with using the simulator as a computer game, and the second perspective looks at the simulator as a socio-cultural artefact. Furthermore the article discusses four different ways the simulator can be looked upon as a useful learning resource when educating students of a military profession.Keywords: Learning, military, profession, simulator.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12171357 Characterization of Liver Leukocyte Infiltrates and Features of Cytokine Profile under Viral Hepatitis-Induced Immunosuppression
Authors: Olga V. Lebedinskaya, Irina N. Kabanovskaya, Anna S. Lasareva, Nelly K. Akhmatova, Anatoliy P. Godovalov, Andrey V. Horinko, Mikhail V. Kiselevsky
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The nature, prevalence, cellular composition of leukocyte infiltrates and immunohistochemical characteristics of their constituent cells in the liver of patients with chronic viral hepatitis B and C were investigated. It was found that the area of distribution and cellular composition of infiltrates depended on the virus type and process activity. The expediency of immunohistochemical study using leukocyte infiltrates from liver biopsies of patients with viral hepatitis aimed at clarifying diagnosis, making prognosis, and choice of optimal treatment with elements of immune correction is emphasized.Keywords: Viral hepatitis, leukocyte infiltration, immunohistochemical characteristics, immunosupression.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17001356 Unconventional Calculus Spreadsheet Functions
Authors: Chahid K. Ghaddar
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The spreadsheet engine is exploited via a non-conventional mechanism to enable novel worksheet solver functions for computational calculus. The solver functions bypass inherent restrictions on built-in math and user defined functions by taking variable formulas as a new type of argument while retaining purity and recursion properties. The enabling mechanism permits integration of numerical algorithms into worksheet functions for solving virtually any computational problem that can be modelled by formulas and variables. Several examples are presented for computing integrals, derivatives, and systems of deferential-algebraic equations. Incorporation of the worksheet solver functions with the ubiquitous spreadsheet extend the utility of the latter as a powerful tool for computational mathematics.Keywords: Calculus functions, nonlinear systems, differential algebraic equations, solvers, spreadsheet.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24591355 Encoding and Compressing Data for Decreasing Number of Switches in Baseline Networks
Authors: Mohammad Ali Jabraeil Jamali, Ahmad Khademzadeh, Hasan Asil, Amir Asil
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This method decrease usage power (expenditure) in networks on chips (NOC). This method data coding for data transferring in order to reduces expenditure. This method uses data compression reduces the size. Expenditure calculation in NOC occurs inside of NOC based on grown models and transitive activities in entry ports. The goal of simulating is to weigh expenditure for encoding, decoding and compressing in Baseline networks and reduction of switches in this type of networks. KeywordsNetworks on chip, Compression, Encoding, Baseline networks, Banyan networks.
Keywords: Networks on chip, Compression, Encoding, Baseline networks, Banyan networks
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19821354 Adaptive Algorithm to Predict the QoS of Web Processes and Workflows
Authors: Jorge Cardoso
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Workflow Management Systems (WfMS) alloworganizations to streamline and automate business processes and reengineer their structure. One important requirement for this type of system is the management and computation of the Quality of Service(QoS) of processes and workflows. Currently, a range of Web processes and workflow languages exist. Each language can be characterized by the set of patterns they support. Developing andimplementing a suitable and generic algorithm to compute the QoSof processes that have been designed using different languages is a difficult task. This is because some patterns are specific to particular process languages and new patterns may be introduced in future versions of a language. In this paper, we describe an adaptive algorithm implemented to cope with these two problems. The algorithm is called adaptive since it can be dynamically changed as the patterns of a process language also change.
Keywords: quality of service, web processes, workflows, web services
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20131353 Critical Success Factors of Information Technology Projects
Authors: Md. Athar Imtiaz, Abduljalil S. Al-Mudhary, Md. Taha Mirhashemi, Roslina Ibrahim
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Information Technology (IT) is being used by almost all organizations throughout the world. However its success at supporting and improving business is debatable. There is always the risk of IT project failure and studies have proven that a large number of IT projects indeed do fail. There are many components that further the success of IT projects; these have been studied in previous studies. Studies have found the most necessary components for success in software development projects, executive information systems etc. In this study previous literatures that have looked into these success promoting factors have been critically reviewed and analyzed. 15 Critical Success Factors (CSF) of IT projects were enlisted and examined. These factors can be applied to all IT projects and is not specific to a particular type of IT/IS project. A hypothesis was also generated after the evaluation of the factors.
Keywords: Critical Success Factors, CSF, IT Projects, IS Projects, Software Development Projects.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 124551352 Inexact Alternating Direction Method for Variational Inequality Problems with Linear Equality Constraints
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In this article, a new inexact alternating direction method(ADM) is proposed for solving a class of variational inequality problems. At each iteration, the new method firstly solves the resulting subproblems of ADM approximately to generate an temporal point ˜xk, and then the multiplier yk is updated to get the new iterate yk+1. In order to get xk+1, we adopt a new descent direction which is simple compared with the existing prediction-correction type ADMs. For the inexact ADM, the resulting proximal subproblem has closedform solution when the proximal parameter and inexact term are chosen appropriately. We show the efficiency of the inexact ADM numerically by some preliminary numerical experiments.
Keywords: variational inequality problems, alternating direction method, global convergence
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14981351 A Review on Enhanced Dynamic Clustering in WSN
Authors: M. Sangeetha, A. Sabari, K. Elakkiya
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Recent advancement in wireless internetworking has presented a number of dynamic routing protocols based on sensor networks. At present, a number of revisions are made based on their energy efficiency, lifetime and mobility. However, to the best of our knowledge no extensive survey of this special type has been prepared. At present, review is needed in this area where cluster-based structures for dynamic wireless networks are to be discussed. In this paper, we examine and compare several aspects and characteristics of some extensively explored hierarchical dynamic clustering protocols in wireless sensor networks. This document also presents a discussion on the future research topics and the challenges of dynamic hierarchical clustering in wireless sensor networks.Keywords: Dynamic cluster, Hierarchical clustering, Wireless sensor networks.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13761350 Assessing the Problems of Pumping Stations: A Case Study of Boneh Basht Pumping Station
Authors: Emad Hazbkhah, Abdolreza Zahiri, Hossein Ghorbanizade Kharazi, Afshin Kiani
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Establishing pumping stations is one of the most common ways of providing water from rivers. There are many issues involved in the design and operation of pumping stations most important of which is the problem of sedimentation. One of the significant issues which must be taken into consideration in designing pumping stations is the operation method and technical matters related to it. Safety and convenience of operation is one of the issues that must be always considered by the designer. Some of the major issues in making decisions regarding the type of design for the station are geographical condition, the location of the station and availability of experts in maintenance and operation of the station. Dimensions of the station must allow free movement for checking and operating pumps after installation of pumps and plumbing system.
Keywords: Boneh Basht, Iran, pumping station.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23011349 The Role of Private Equity during Global Crises
Authors: Libena Cernohorska, Veronika Linhartova, Michal Sinka, Petr Teply
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The term private equity usually refers to any type of equity investment in an asset in which the equity is not freely tradable on a public stock market. Some researchers believe that private equity contributed to the extent of the crisis and increased the pace of its spread over the world. We do not agree with this. On the other hand, we argue that during the economic recession private equity might become an important source of funds for firms with special needs (e.g. for firms seeking buyout financing, venture capital, expansion capital or distress debt financing). However, over-regulation of private equity in both the European Union and the US can slow down this specific funding channel to the economy and deepen credit crunch during global crises.Keywords: scredit lunch, distress debt, global crisis, private equity, regulation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18651348 Separation of CO2 Using MFI-Alumina Nanocomposite Hollow Fiber Ion-Exchanged with Alkali Metal Cation
Authors: A. Alshebani, Y. Swesi, S. Mrayed, F. Altaher, I. Musbah
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Cs-type nanocomposite zeolite membrane was successfully synthesized on an alumina ceramic hollow fibre with a mean outer diameter of 1.7 mm; cesium cationic exchange test was carried out inside test module with mean wall thickness of 230 μm and an average crossing pore size smaller than 0.2 μm. Separation factor of n-butane/H2 obtained indicate that a relatively high quality closed to 20. Maxwell-Stefan modeling provides an equivalent thickness lower than 1 µm. To compare the difference an application to CO2/N2 separation has been achieved, reaching separation factors close to (4,18) before and after cation exchange on H-zeolite membrane formed within the pores of a ceramic alumina substrate.
Keywords: MFI membrane, nanocomposite, Ceramic hollow fibre, CO2, Ion-exchange.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20161347 Peer Corrective Feedback on Written Errors in Computer-Mediated Communication
Authors: S. H. J. Liu
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This paper aims to explore the role of peer Corrective Feedback (CF) in improving written productions by English-as-a- foreign-language (EFL) learners who work together via Wikispaces. It attempted to determine the effect of peer CF on form accuracy in English, such as grammar and lexis. Thirty-four EFL learners at the tertiary level were randomly assigned into the experimental (with peer feedback) or the control (without peer feedback) group; each group was subdivided into small groups of two or three. This resulted in six and seven small groups in the experimental and control groups, respectively. In the experimental group, each learner played a role as an assessor (providing feedback to others), as well as an assessee (receiving feedback from others). Each participant was asked to compose his/her written work and revise it based on the feedback. In the control group, on the other hand, learners neither provided nor received feedback but composed and revised their written work on their own. Data collected from learners’ compositions and post-task interviews were analyzed and reported in this study. Following the completeness of three writing tasks, 10 participants were selected and interviewed individually regarding their perception of collaborative learning in the Computer-Mediated Communication (CMC) environment. Language aspects to be analyzed included lexis (e.g., appropriate use of words), verb tenses (e.g., present and past simple), prepositions (e.g., in, on, and between), nouns, and articles (e.g., a/an). Feedback types consisted of CF, affective, suggestive, and didactic. Frequencies of feedback types and the accuracy of the language aspects were calculated. The results first suggested that accurate items were found more in the experimental group than in the control group. Such results entail that those who worked collaboratively outperformed those who worked non-collaboratively on the accuracy of linguistic aspects. Furthermore, the first type of CF (e.g., corrections directly related to linguistic errors) was found to be the most frequently employed type, whereas affective and didactic were the least used by the experimental group. The results further indicated that most participants perceived that peer CF was helpful in improving the language accuracy, and they demonstrated a favorable attitude toward working with others in the CMC environment. Moreover, some participants stated that when they provided feedback to their peers, they tended to pay attention to linguistic errors in their peers’ work but overlook their own errors (e.g., past simple tense) when writing. Finally, L2 or FL teachers or practitioners are encouraged to employ CMC technologies to train their students to give each other feedback in writing to improve the accuracy of the language and to motivate them to attend to the language system.
Keywords: Peer corrective feedback, computer-mediated communication, second or foreign language learning, Wikispaces.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14491346 Engineering Study and Equipment Design: Effects of Temperature and design variables on Yield of a Multi-Stage Distillator
Authors: A.Diaf, Z.Tigrine, H. Aburideh, D.Tassalit , F.Alaoui, B .Abbad
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The distillation process in the general sense is a relatively simple technique from the standpoints of its principles. When dedicating distillation to water treatment and specifically producing fresh water from sea, ocean and/ briny waters it is interesting to notice that distillation has no limitations or domains of applicability regarding the nature or the type of the feedstock water. This is not the case however for other techniques that are technologically quite complex, necessitate bigger capital investments and are limited in their usability. In a previous paper we have explored some of the effects of temperature on yield. In this paper, we continue building onto that knowledge base and focus on the effects of several additional engineering and design variables on productivity.Keywords: Distillation, Desalination, Multi-Stage still, Solar Energy
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17991345 Quantitative Analysis of Construction Waste in the City of Novi Sad, Serbia
Authors: Nikola Karanovic, Aleksandar Djuric
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This paper introduces a method of calculating the quantities of construction materials and construction waste on site in city of Novi Sad. In buildings is about 40% of the total weight of materials that are in circulation in the world economic space. The best solution for this waste is to be stored at source, at the point of generation. There are several treatment options for this type of waste, reduction at source, reuse, recycling. Beside its negative effects on the environment, construction waste can be and resource. Novi Sad is divided in 16 single family resident zones and 10 multi family resident zones. For every zone of the city, quantities of used construction materials and construction waste were obtained. Rational use of natural resources is an essential factor in applying the principles of development with savings.Keywords: Construction materials, Construction waste, Novi Sad, Recycling
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16541344 Influence of Type of Burner on NOx Emission Characteristics from Combustion of Palm Methyl Ester
Authors: Nozomu Hashimoto, Hiroyuki Nishida, Yasushi Ozawa, Tetsushiro Iwatsubo, Jun Inumaru
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Palm methyl ester (PME) is one of the alternative biomass fuels to liquid fossil fuels. To investigate the combustion characteristics of PME as an alternative fuel for gas turbines, combustion experiments using two types of burners under atmospheric pressure were performed. One of the burners has a configuration making strong non-premixed flame, whereas the other has a configuration promoting prevaporization of fuel droplets. The results show that the NOx emissions can be reduced by employing the latter burner without accumulation of soot when PME is used as a fuel. A burner configuration promoting prevaporzation of fuel droplets is recommended for PME.Keywords: Palm methyl ester (PME), biodiesel fuel, gas turbine, spray combustion, NOx emission.
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