Search results for: Heat sources
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2173

Search results for: Heat sources

913 NOx Emission and Computational Analysis of Jatropha Curcus Fuel and Crude Oil

Authors: Vipan Kumar Sohpal, Rajesh K Sharma

Abstract:

Diminishing of conventional fuels and hysterical vehicles emission leads to deterioration of the environment, which emphasize the research to work on biofuels. Biofuels from different sources attract the attention of research due to low emission and biodegradability. Emission of carbon monoxide, carbon dioxide and H-C reduced drastically using Biofuels (B-20) combustion. Contrary to the conventional fuel, engine emission results indicated that nitrous oxide emission is higher in Biofuels. So this paper examines and compares the nitrogen oxide emission of Jatropha Curcus (JCO) B-20% blends with the vegetable oil. In addition to that computational analysis of crude non edible oil performed to assess the impact of composition on emission quality. In conclusion, JCO have the potential feedstock for the biodiesel production after the genetic modification in the plant.

Keywords: Jatropha Curcus, computational analysis, emissions, biofuels.

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912 Pedestrian Areas and Sustainable Development

Authors: Khashayar Kashani Jou

Abstract:

Transportation is one of the most fundamental challenges of urban development in contemporary world. On the other hand, sustainable urban development has received tremendous public attention in the last few years. This trend in addition to other factors such as energy cost, environmental concerns, traffic congestion and the feeling of lack of belonging have contributed to the development of pedestrian areas. The purpose of this paper is to study the role of walkable streets in sustainable development of cities. Accordingly, a documentary research through valid sources has been utilized to substantiate this study. The findings demonstrate that walking can lead to sustainable urban development from physical, social, environmental, cultural, economic and political aspects. Also, pedestrian areas –which are the main context of walking- act as focal points of development in cities and have a great effect on modifying and stimulating of their adjacent urban spaces.

Keywords: Pedestrian area, Sustainable urban development, Walking, Woonerf

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911 Performance and Economic Evaluation of a Hybrid Photovoltaic/Thermal Solar System in Northern China

Authors: E. Sok, Y. Zhuo, S. Wang

Abstract:

A hybrid Photovoltaic/Thermal (PV/T) solar system integrates photovoltaic and solar thermal technologies into one single solar energy device, with dual generation of electricity and heat energy. The aim of the present study is to evaluate the potential for introduction of the PV/T technology into Northern China. For this purpose, outdoor experiments were conducted on a prototype of a PV/T water-heating system. The annual thermal and electrical performances were investigated under the climatic conditions of Beijing. An economic analysis of the system was then carried out, followed by a sensitivity study. The analysis revealed that the hybrid system is not economically attractive with the current market and energy prices. However, considering the continuous commitment of the Chinese government towards policy development in the renewable energy sector, and technological improvements like the increasing cost-effectiveness of PV cells, PV/Thermal technology may become economically viable in the near future.

Keywords: Hybrid Photovoltaic/Thermal (PV/T), Solar energy, Economic analysis

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910 Change of the Thermal Conductivity of Polystyrene Insulation in term of Temperature at the Mid Thickness of the Insulation Material: Impact on the Cooling Load

Authors: M. Khoukhi

Abstract:

Accurate prediction of the cooling/heating load and consequently, the sizing of the heating, ventilating, and air-conditioning equipment require precise calculation of the heat transfer mainly by conduction through envelope components of a building. The thermal resistance of most thermal insulation materials depends on the operating temperature. The temperature to which the insulation materials are exposed varies, depending on the thermal resistance of the materials, the location of the insulation layer within the assembly system, and the effective temperature which depends on the amount of solar radiation received on the surface of the assembly. The main objective of this paper is to investigate the change of the thermal conductivity of polystyrene insulation material in terms of the temperature at the mid-thickness of the material and its effect on the cooling load required by the building.

Keywords: Operating temperature, polystyrene insulation, thermal conductivity, cooling load.

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909 Thermal and Flammability Properties of Paraffin/Nanoclay Composite Phase Change Materials Incorporated in Building Materials for Thermal Energy Storage

Authors: Awni H. Alkhazaleh, Baljinder K. Kandola

Abstract:

In this study, a form-stable composite Paraffin/Nanoclay (PA-NC) has been prepared by absorbing PA into porous particles of NC to be used for low-temperature latent heat thermal energy storage. The leakage test shows that the maximum mass fraction of PA that can be incorporated in NC without leakage is 60 wt.%. Differential scanning calorimetry (DSC) has been used to measure the thermal properties of the PA and PA-NC both before and after incorporation in plasterboard (PL). The mechanical performance of the samples has been evaluated in flexural mode. The thermal energy storage performance has been studied using a small test chamber (100 mm × 100 mm × 100 mm) made from 10 mm thick PL and measuring the temperatures using thermocouples. The flammability of the PL+PL-NC has been discussed using a cone calorimeter. The results indicate that the form composite PA has good potential for use as thermal energy storage materials in building applications.

Keywords: Flammability, paraffin, plasterboard, thermal energy storage.

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908 Role of Credit on Production Efficiency of Farming Sector in Pakistan(A Data Envelopment Analysis)

Authors: Saima Ayaz, Zakir Hussain, Maqbool Hussain Sial

Abstract:

The study identified the sources of production inefficiency of the farming sector in district Faisalabad in the Punjab province of Pakistan. Data Envelopment Analysis (DEA) technique was utilized at farm level survey data of 300 farmers for the year 2009. The overall mean efficiency score was 0.78 indicating 22 percent inefficiency of the sample farmers. Computed efficiency scores were then regressed on farm specific variables using Tobit regression analysis. Farming experience, education, access to farming credit, herd size and number of cultivation practices showed constructive and significant effect on the farmer-s technical efficiency.

Keywords: Agricultural credit, DEA, Technical efficiency, Tobit analysis

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907 A Comparative CFD Study on Solar Dimple Plate Collector with Flat Plate Collector to Augment the Thermal Performance

Authors: Manjunath M. S., K. Vasudeva Karanth, N. Yagnesh Sharma

Abstract:

It is well known that surface enhancements play an important role in augmenting the thermal performance of flat plate solar collector. In this paper, an attempt is made to explain in a comparative way the effect of surface geometry of solar collector having dimple geometry with that of a flat plate solar collector of the same size. A CFD analysis was carried out for the two cases, subjected to a constant heat flux of 600W/m2 and 1000W/m2. It can be inferred from the study that the absorber plate temperature shows a rise of average surface temperature of about 50C for the dimple solar collector when compared to a flat plate solar collector. Most importantly, the average exit water temperature shows a marked improvement of about 5.50C for a dimple solar collector as compared to that of a flat plate solar collector.

Keywords: CFD, dimple-collector, flat-plate-collector, surface-enhancement, thermal-performance.

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906 A Study of Recycle Materials to Develop for Auto Part

Authors: Sittichai Kaewkuekool, Vanchai Laemlaksakul

Abstract:

At the present, auto part industries have become higher challenge in strategy market. As this consequence, manufacturers need to have better response to customers in terms of quality, cost, and delivery time. Moreover, they need to have a good management in factory to comply with international standard maximum capacity and lower cost. This would lead companies to have to order standard part from aboard and become the major cost of inventory. The development of auto part research by recycling materials experiment is to compare the auto parts from recycle materials to international auto parts (CKD). Factors studied in this research were the recycle material ratios of PU-foam, felt, and fabric. Results of recycling materials were considered in terms of qualities and properties on the parameters such as weight, sound absorption, water absorption, tensile strength, elongation, and heat resistance with the CKD. The results were showed that recycling materials would be used to replace for the CKD.

Keywords: International auto parts, recycling materials.

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905 Thermodynamic Performance of a Combined Power and Ejector Refrigeration Cycle

Authors: Hyung Jong Ko, Kyoung Hoon Kim

Abstract:

In this study thermodynamic performance analysis of a combined organic Rankine cycle and ejector refrigeration cycle is carried out for use of low-grade heat source in the form of sensible energy. Special attention is paid to the effects of system parameters including the turbine inlet temperature and turbine inlet pressure on the characteristics of the system such as ratios of mass flow rate, net work production, and refrigeration capacity as well as the coefficient of performance and exergy efficiency of the system. Results show that for a given source the coefficient of performance increases with increasing of the turbine inlet pressure. However, the exergy efficiency has an optimal condition with respect to the turbine inlet pressure.

Keywords: Coefficient of performance, ejector refrigeration cycle, exergy efficiency, low-grade energy, organic rankine cycle.

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904 Energy Analysis of Pressurized Solid Oxide Fuel Cell Combined Power Turbine

Authors: M. Ayazi, R. Karami, B. Kamkari

Abstract:

Solid oxide fuel cells have been considered in the last years as one of the most promising technologies for very highefficiency electric energy generation from hydrogen or other hydrocarbons, both with simple fuel cell plants and with integrated gas turbine-fuel cell systems. In the present study, a detailed thermodynamic analysis has been carried out. Mass and exergy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of combined cycle. Moreover, different sources of irreversibilities within the SOFC stack have been discussed and a parametric study conducted to evaluate the effect of temperature as well as pressure on SOFC irreversibilities and its performance. In this investigation methane and hydrogen have been used for fueling the SOFC stack and combustion chamber.

Keywords: SOFC, Energy, Power turbine, Irreversibility.

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903 Studies on the Feasibility of Cow’s Urine as Non-Conventional Energy Sources

Authors: Raj Kumar Rajak, Bharat Mishra

Abstract:

Bio-batteries represent an entirely new long-term, reasonable, reachable, and eco-friendly approach to generation of sustainable energy. In the present experimental work, we have studied the effect of the generation of power by bio-battery using different electrode pairs. The tests show that it is possible to generate electricity using cow’s urine as an electrolyte. C-Mg electrode pair shows maximum Voltage and Short Circuit Current (SCC), while C-Zn electrode pair shows less Open Circuit Voltage (OCV) and SCC. By the studies of cow urine and different electrodes, it is found that C-Zn electrode battery is more economical. The cow urine battery with C-Zn electrode provides maximum power (707.4 mW) and durability (up to 145 h). This result shows that the bio-batteries have the potency to full fill the need of electricity demand for lower energy equipment.

Keywords: Bio-batteries, cow’s urine, electrodes, non-conventional.

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902 Enhanced Dimensional Stability of Rigid PVC Foams Using Glass Fibers

Authors: Nidal H. Abu-Zahra, Murtatha M. Jamel, Parisa Khoshnoud, Subhashini Gunashekar

Abstract:

Two types of glass fibers having different lengths (1/16" and 1/32") were added into rigid PVC foams to enhance the dimensional stability of extruded rigid Polyvinyl Chloride (PVC) foam at different concentrations (0-20 phr) using a single screw profile extruder. PVC foam-glass fiber composites (PVC-GF) were characterized for their dimensional stability, structural, thermal, and mechanical properties. Experimental results show that the dimensional stability, heat resistance, and storage modulus were enhanced without compromising the tensile and flexural strengths of the composites. Overall, foam composites which were prepared with longer glass fibers exhibit better mechanical and thermal properties than those prepared with shorter glass fibers due to higher interlocking between the fibers and the foam cells, which result in better load distribution in the matrix.

Keywords: Polyvinyl Chloride, PVC Foam, PVC Composites, Glass Fiber Composites.

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901 Molecular Dynamics Simulation of Lubricant Adsorption and Thermal Depletion Instability

Authors: Bei Li, Qiu B. Chen, Chee H. Wong

Abstract:

In this work, we incorporated a quartic bond potential into a coarse-grained bead-spring model to study lubricant adsorption on a solid surface as well as depletion instability. The surface tension density and the number density profiles were examined to verify the solid-liquid and liquid-vapor interfaces during heat treatment. It was found that both the liquid-vapor interfacial thickness and the solid-vapor separation increase with the temperatureT* when T*is below the phase transition temperature Tc *. At high temperatures (T*>Tc *), the solid-vapor separation decreases gradually as the temperature increases. In addition, we evaluated the lubricant weight and bond loss profiles at different temperatures. It was observed that the lubricant desorption is favored over decomposition and is the main cause of the lubricant failure at the head disk interface in our simulations.

Keywords: Depletion instability, Lubricant film, Thermal adsorption, Molecular dynamics (MD).

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900 To Study the Parametric Effects on Optimality of Various Feeding Sequences of a Multieffect Evaporators in Paper Industry using Mathematical Modeling and Simulation with MATLAB

Authors: Deepak Kumar, Vivek Kumar, V. P. Singh

Abstract:

This paper describes a steady state model of a multiple effect evaporator system for simulation and control purposes. The model includes overall as well as component mass balance equations, energy balance equations and heat transfer rate equations for area calculations for all the effects. Each effect in the process is represented by a number of variables which are related by the energy and material balance equations for the feed, product and vapor flow for backward, mixed and split feed. For simulation 'fsolve' solver in MATLAB source code is used. The optimality of three sequences i.e. backward, mixed and splitting feed is studied by varying the various input parameters.

Keywords: MATLAB "fsolve" solver, multiple effectevaporators, black liquor, feeding sequences.

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899 Scots Pine Needles as Bioindicators in Determining the Aerial Distribution Pattern of Sulphur Emissions around Industrial Plants

Authors: Risto Pöykiö, Jari Hietala, Hannu Nurmesniemi

Abstract:

In this study, the Scots pine (Pinus sylvestris L.) C needles (i.e. the current-year-needles) were used as bioindicators in determining the aerial distribution pattern of sulphur emissions around industrial point sources at Kemi, Northern Finland. The average sulphur concentration in the C needles was 897 mg/kg (d.w.), with a standard deviation of 118 mg/kg (d.w.) and range 740 – 1350 mg/kg (d.w.). According to results in this study, Scots pine needles (Pinus sylvestris L.) appear to be an ideal bioindicators for identifying atmospheric sulphur pollution derived from industrial plants and can complement the information provided by plant mapping studies around industrial plants.

Keywords: Emission, Sulphur, Scots Pine, Pinus sylvestris

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898 Multimethod Approach to Research in Interlanguage Pragmatics

Authors: Saad Al-Gahtani, Ghassan H Al Shatter

Abstract:

Argument over the use of particular method in interlanguage pragmatics has increased recently. Researchers argued the advantages and disadvantages of each method either natural or elicited. Findings of different studies indicated that the use of one method may not provide enough data to answer all its questions. The current study investigated the validity of using multimethod approach in interlanguage pragmatics to understand the development of requests in Arabic as a second language (Arabic L2). To this end, the study adopted two methods belong to two types of data sources: the institutional discourse (natural data), and the role play (elicited data). Participants were 117 learners of Arabic L2 at the university level, representing four levels (beginners, low-intermediate, highintermediate, and advanced). Results showed that using two or more methods in interlanguage pragmatics affect the size and nature of data.

Keywords: Arabic L2, Development of requests, Interlanguage Pragmatics, Multimethod approach.

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897 Information Needs and Information Usage of the Older Person Club’s Members in Bangkok

Authors: Siriporn Poolsuwan

Abstract:

This research aims to explore the information needs, information usages, and problems of information usage of the older people club’s members in Dusit district, Bangkok. There are 12 clubs and 746 club’s members in this district. The research results use for older person service in this district. Data is gathered from 252 club’s members by using questionnaires. The quantitative approach uses in research by percentage, means and standard deviation. The results are as follows (1) The older people need Information for entertainment, occupation and academic in the field of short story, computer work, and religion and morality. (2) The participants use Information from various sources. (3) The Problem of information usage is their language skills because of the older people’s literacy problem.

Keywords: Information Behavior, Older Person, Information Seeking.

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896 Energy Management Techniques in Mobile Robots

Authors: G. Gurguze, I. Turkoglu

Abstract:

Today, the developing features of technological tools with limited energy resources have made it necessary to use energy efficiently. Energy management techniques have emerged for this purpose. As with every field, energy management is vital for robots that are being used in many areas from industry to daily life and that are thought to take up more spaces in the future. Particularly, effective power management in autonomous and multi robots, which are getting more complicated and increasing day by day, will improve the performance and success. In this study, robot management algorithms, usage of renewable and hybrid energy sources, robot motion patterns, robot designs, sharing strategies of workloads in multiple robots, road and mission planning algorithms are discussed for efficient use of energy resources by mobile robots. These techniques have been evaluated in terms of efficient use of existing energy resources and energy management in robots.

Keywords: Energy management, mobile robot, robot administration, robot management, robot planning.

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895 Charge-Pump with a Regulated Cascode Circuit for Reducing Current Mismatch in PLLs

Authors: Jae Hyung Noh, Hang Geun Jeong

Abstract:

The charge-pump circuit is an important component in a phase-locked loop (PLL). The charge-pump converts Up and Down signals from the phase/frequency detector (PFD) into current. A conventional CMOS charge-pump circuit consists of two switched current sources that pump charge into or out of the loop filter according to two logical inputs. The mismatch between the charging current and the discharging current causes phase offset and reference spurs in a PLL. We propose a new charge-pump circuit to reduce the current mismatch by using a regulated cascode circuit. The proposed charge-pump circuit is designed and simulated by spectre with TSMC 0.18-μm 1.8-V CMOS technology.

Keywords: Phase-locked loop (PLL), charge-pump, phase/frequency detector (PFD), regulated cascode.

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894 Analysis of Tool-Chip Interface Temperature with FEM and Empirical Verification

Authors: M. Bagheri, P. Mottaghizadeh

Abstract:

Reliable information about tool temperature distribution is of central importance in metal cutting. In this study, tool-chip interface temperature was determined in cutting of ST37 steel workpiece by applying HSS as the cutting tool in dry turning. Two different approaches were implemented for temperature measuring: an embedded thermocouple (RTD) in to the cutting tool and infrared (IR) camera. Comparisons are made between experimental data and results of MSC.SuperForm and FLUENT software. An investigation of heat generation in cutting tool was performed by varying cutting parameters at the stable cutting tool geometry and results were saved in a computer; then the diagrams of tool temperature vs. various cutting parameters were obtained. The experimental results reveal that the main factors of the increasing cutting temperature are cutting speed (V ), feed rate ( S ) and depth of cut ( h ), respectively. It was also determined that simultaneously change in cutting speed and feed rate has the maximum effect on increasing cutting temperature.

Keywords: Cutting parameters, Finite element modeling, Temperature measurement, Tool-chip interface temperature.

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893 Constitutional Complaint as an Instrument of Fulfilling the Worker ׳s Rights in Croatian Legal System

Authors: Dragana Bjelić, Mirela Mezak Stastny

Abstract:

This paper begins with formal defining of human rights and freedoms, and the basic document regarding the said subject is undoubtedly French Declaration of the Rights of Man and of the Citizen from 789. This paper furthermore parses legal sources relevant for the workers' rights in legal system of the Republic of Croatia, international contracts and the Labour Act, which is also a master bill regarding workers' rights The authors are also dealing with issues of Constitutional Court of the Republic of Croatia and its' position in judicial system of the Republic of Croatia, as well as with the specifics of Constitutional Complaint, and the crucial part of the paper is based on the research conducted with an aim to determine implementation of rights and liberties guaranteed by the articles 54. and 55. of the Constitution of the Republic of Croatia by means of Constitutional Complaint.

Keywords: a right to work, a freedom of work, Constitutional Court of Republic of Croatia, Constitutional Complaint.

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892 A Study of Water Consumption in Two Malaysian Resorts

Authors: Fu E. Tang

Abstract:

In the effort to reduce water consumption for resorts, more water conservation practices need to be implemented. Hence water audits need to be performed to obtain a baseline of water consumption, before planning water conservation practices. In this study, a water audit framework specifically for resorts was created, and the audit was performed on two resorts: Resort A in Langkawi, Malaysia; and Resort B in Miri, Malaysia. From the audit, the total daily water consumption for Resorts A and B were estimated to be 180m3 and 330 m3 respectively, while the actual water consumption (based on water meter readings) were 175 m3 and 325 m3. This suggests that the audit framework is reasonably accurate and may be used to account for most of the water consumption sources in a resort. The daily water consumption per guest is about 500 litres. The water consumption of both resorts is poorly rated compared with established benchmarks. Water conservation measures were suggested for both resorts.

Keywords: water consumption patterns, water conservation practices, water audit, water audit framework.

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891 Understanding and Measuring Trust Evolution Effectiveness in Peer-to-Peer Computing Systems

Authors: Farag Azzedin, Ali Rizvi

Abstract:

In any trust model, the two information sources that a peer relies on to predict trustworthiness of another peer are direct experience as well as reputation. These two vital components evolve over time. Trust evolution is an important issue, where the objective is to observe a sequence of past values of a trust parameter and determine the future estimates. Unfortunately, trust evolution algorithms received little attention and the proposed algorithms in the literature do not comply with the conditions and the nature of trust. This paper contributes to this important problem in the following ways: (a) presents an algorithm that manages and models trust evolution in a P2P environment, (b) devises new mechanisms for effectively maintaining trust values based on the conditions that influence trust evolution , and (c) introduces a new methodology for incorporating trust-nurture incentives into the trust evolution algorithm. Simulation experiments are carried out to evaluate our trust evolution algorithm.

Keywords: P2P, Trust, Reputation, Incentives.

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890 Powering Pacemakers from Heart Pressure Variation with Piezoelectric Energy Harvesters

Authors: A. Mathieu, B. Aubry, E. Chhim, M. Jobe, M. Arnaud

Abstract:

Present project consists in a study and a development of piezoelectric devices for supplying power to new generation pacemakers. They are miniaturized leadless implants without battery placed directly in right ventricle. Amongst different acceptable energy sources in cardiac environment, we choose the solution of a device based on conversion of the energy produced by pressure variation inside the heart into electrical energy. The proposed energy harvesters can meet the power requirements of pacemakers, and can be a good solution to solve the problem of regular surgical operation. With further development, proposed device should provide enough energy to allow pacemakers autonomy, and could be good candidate for next pacemaker generation.

Keywords: Energy harvester, heart, leadless pacemaker, piezoelectric cells, pressure variation.

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889 Characteristic on Compressive Strength of Blast Slag and Fly Ash Hybrid Geopolymer Mortar

Authors: G. S. Ryu, K. T. Koh, H. Y. Kim, G. H. An, D. W. Seo

Abstract:

Geopolymer mortar is produced by alkaline activation of pozzolanic materials such as fly ground granulated blast-furnace slag (GGBFS) and fly ash (FA). Its unique reaction pathway facilitates rapid strength development in comparison with hydration of ordinary Portland cement (OPC). Geopolymer can be fabricated using various types and dosages of alkali-activator, which effectively gives a wider control over the performance of the final product. The present study investigates the effect of types of precursors and curing conditions on the fresh state and strength development characteristics of geopolymers, thereby comparatively exploring the effect of precursors from various sources of origin. The obtained result showed that the setting time and strength development of the specimens with the identical mix proportion but different precursors displayed significant variations.

Keywords: Alkali-activated material, blast furnace slag, fly ash, Flowability, strength development.

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888 A Study on Energy-efficient Temperature Control

Authors: Mitsuyuki Kawakami, Kimihiro Yamanaka

Abstract:

The top-heavy demographic of low birth-rate and longer lifespan is a growing social problem, and one of its expected effects will be a shortage of young workers and a growing reliance on a workforce of middle-aged and older people. However, the environment of today's industrial workplace is not particularly suited to middle-aged and older workers, one notable problem being temperature control. Higher temperatures can cause health problems such as heat stroke, and the number of cases increases sharply in people over 65. Moreover, in conditions above 33°C, older people can develop circulatory system disorders, and also have a higher chance of suffering a fatal heart attack. We therefore propose a new method for controlling temperature in the indoor workplace. In this study two different verification experiments were conducted, with the proposed temperature control method being tested in cargo containers and conventional houses. The method's effectiveness was apparent in measurements of temperature and electricity consumption

Keywords: CO2 reduction, Energy saving, Temperature control

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887 Small and Medium Enterprises (SMEs) Financing Practice and Accessing Bank Loan Issues -The Case of Libya

Authors: Kalsom Abd Wahab, Khalid Hassan Abdesamed

Abstract:

The purpose of this paper is to examine the financing practices of SMEs in Libya in two different phases of business life cycle: start-up and matured stages. Moreover, SMEs- accessing bank loan issues is also identified. The study was conducted by taking into account the aspect of demand. The findings are based on a sample of 76 SMEs in Libya through the adoption of questionnaires. The results have pinpointed several things- evidently, SMEs use informal financing sources which prefer personal savings; SME owners are willing to apply for bank loan, that the most pressing problem has been identified, not to apply bank loan is loan with interest (religion factor).

Keywords: SMEs, Formal Finance (loan from bank), Informal Finance, Loan with interest (religion factor), Libya.

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886 A Thirteen-Level Asymmetrical Cascaded H-Bridge Single Phase Inverter

Authors: P. Varalaxmi, A. Kirubakaran

Abstract:

This paper presents a thirteen-level asymmetrical cascaded H-bridge single phase inverter. In this configuration, the desired output voltage level is achieved by connecting the DC sources in different combinations by triggering the switches. The modes of operation are explained well for positive level generations. Moreover, a comparison is made with conventional topologies of diode clamped, flying capacitors and cascaded-H-bridge and some recently proposed topologies to show the significance of the proposed topology in terms of reduced part counts. The simulation work has been carried out in MATLAB/Simulink environment. The experimental work is also carried out for lower rating to verify the performance and feasibility of the proposed topology. Further the results are presented for different loading conditions.

Keywords: Multilevel inverter, pulse width modulation, total harmonic distortion, THD.

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885 Modelling of Heating and Evaporation of Biodiesel Fuel Droplets

Authors: Mansour Al Qubeissi, Sergei S. Sazhin, Cyril Crua, Morgan R. Heikal

Abstract:

This paper presents the application of the Discrete Component Model for heating and evaporation to multi-component biodiesel fuel droplets in direct injection internal combustion engines. This model takes into account the effects of temperature gradient, recirculation and species diffusion inside droplets. A distinctive feature of the model used in the analysis is that it is based on the analytical solutions to the temperature and species diffusion equations inside the droplets. Nineteen types of biodiesel fuels are considered. It is shown that a simplistic model, based on the approximation of biodiesel fuel by a single component or ignoring the diffusion of components of biodiesel fuel, leads to noticeable errors in predicted droplet evaporation time and time evolution of droplet surface temperature and radius.

Keywords: Heat/Mass Transfer, Biodiesel, Multi-component Fuel, Droplet, Evaporation.

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884 Innovation Strategy in Slovak Businesses

Authors: V. Lendel, M. Varmus

Abstract:

The aim of the paper is based on detailed analysis of literary sources and carried out research to develop a model development and implementation of innovation strategy in the business. The paper brings the main results of the authors conducted research on a sample of 462 respondents that shows the current situation in the Slovak enterprises in the use of innovation strategy. Carried out research and analysis provided the base for a model development and implementation of innovation strategy in the business, which is in the paper in detail, step by step explained with emphasis on the implementation process. Implementing the innovation strategy is described a separate model. Paper contains recommendations for successful implementation of innovation strategy in the business. These recommendations should serve mainly business managers as valuable tool in implementing the innovation strategy.

Keywords: innovation, innovation strategy, innovative management, innovative potential

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