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Kosmos
Astronomia Astrofizyka
Inne

Kultura
Sztuka dawna i współczesna, muzea i kolekcje

Metoda
Metodologia nauk, Matematyka, Filozofia, Miary i wagi, Pomiary

Materia
Substancje, reakcje, energia
Fizyka, chemia i inżynieria materiałowa

Człowiek
Antropologia kulturowa Socjologia Psychologia Zdrowie i medycyna

Wizje
Przewidywania Kosmologia Religie Ideologia Polityka

Ziemia
Geologia, geofizyka, geochemia, środowisko przyrodnicze

Życie
Biologia, biologia molekularna i genetyka

Cyberprzestrzeń
Technologia cyberprzestrzeni, cyberkultura, media i komunikacja

Działalność
Wiadomości | Gospodarka, biznes, zarządzanie, ekonomia

Technologie
Budownictwo, energetyka, transport, wytwarzanie, technologie informacyjne

Energy Research Journal

http://www.thescipub.com/abstract/10.3844/erjsp.2014.1.3 2014/09/12 - 05:04

Glasses based on Sm3+ doped zinc fluoroborate have been synthesized and characterized. Formation of glass has been investigated in the 30 ZnF2-20 TeO2-(50-x) B2O3-x Sm2O3 matrix. Fast quenching is required to prevent melt crystallization and adequate heat treatment to diminish thermal stress, which results in an efficient amorphous material. The Differential Scanning Calorimeter (DSC), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDAX), stability, density and refractive index have been recorded, calculated, measured and analyzed for the glass samples with different concentrations of Sm3+ ranging between 0 to 3 moL%. Density increases as dopant concentration increases and glass transition temperature Tg ranges between 395 and 420°C. The increase of molar volume with Sm2O3 content indicates that the extension of glass network is due to the increase of the number of NBOs. The results found in this investigation showed that the refractive index of glass does not only depend on the density but also depends on the electronic polarizability of the glass. The increasing stability of the glass samples shows that they are thermally resistant. The presence of NBOs in the glass network is also approved by the decrease in glass transition Temperature (Tg). The variation of the properties with different composition of dopant plays a dominant role in determining a good host material in the field of optics and photonics.

http://www.thescipub.com/abstract/10.3844/erjsp.2013.52.58 2014/07/15 - 21:31

This research paper seeks to explain and analyse the effects of green taxes on investment in renewable energies in the case of the UK. As climate change is challenging the world, different measures and instruments have been implemented to tackle it. The implementation of green taxes on environmental pollution is one example. Even though green taxes aim to reduce greenhouse gas emissions, they also affect investments in renewable energy projects both positively and negatively. Firstly, the topic is seen in the context: The UK energy targets and green taxes are described and the connection between environmental taxes and investments in renewable energies is discussed. This is followed by a discussion and analysis part, which is achieved by collecting and evaluating qualitative and quantitative secondary data that mainly comprises governmental documents, newspaper and academic articles as well as numeric statistics and graphs. It can be seen that on one hand, green taxes, besides cutting on emissions, encourage investment in renewable energies as they put particularly energy intensive organisations under pressure to use more renewable sources, which means that companies will have to change behaviour and fall back on renewables. On the other hand, it can likewise be seen that green taxes come along with negative side effects. This is due to how taxes are implemented and how politicians do not agree on how to handle them. They lead to high energy bills and can have a deterrent effect on investment in renewable energies as companies may choose to obtain more reasonable energy from other countries and sources.

http://www.thescipub.com/abstract/10.3844/erjsp.2013.39.51 2014/04/04 - 23:06

In Thailand, the average wind speed throughout the country is comparatively low for normally-available wind turbine. Designing of a new blade suitable for applications in the average wind speed of 3-7 m sec-1 is, thus, a main objective of this study. High torque has to be obtained properly to generate electricity. In order to design and evaluate performance, our mechanical model has been developed based on Blade Element Momentum theory and, the model is consequently employed to determine the optimized blade shape under constrains that are rotor diameter of wind turbine is not higher than 3 m, design wind velocity is 6 m sec-1, 12 and 24 V battery chargers respectively. New wind turbine blade manually made from fiberglass (GRP) with safety factors of 4 (for 12 V battery) and 2.8 (for 24 V battery). Experimental study is conducted by testing both of commercial blades and our new blade with a specific wind turbine set. We found that, at designed wind velocity, the efficiency of our new wind turbine blade of 27% is obtained while that of the commercial wind turbine is only 16%.

http://www.thescipub.com/abstract/10.3844/erjsp.2013.1.7 2013/08/26 - 10:47

Known disadvantages of high-dense α-U metal fuel (intense radiation growth and radiation swelling, poor compatibility with steel claddings) can be reduced to the minimum by “constructive” approaches based on mechanical restraint of radiation growth and swelling and also on application of protective layers on fuel columns and claddings. Effectiveness of these methods has been confirmed during irradiation of full-sized fuel pins with high-dense metal fuel (γeff≥12.5g h.a./cm3) in the BOR-60 and BN-350 reactors.

http://www.thescipub.com/abstract/10.3844/erjsp.2013.8.14 2013/08/26 - 10:47

This study is to investigate the financial and technological challenges and opportunities facing the utilisation of renewable energy resources in Libya. The work investigates the availability of different renewable energy resources in Libya and the practicality of implementing some of these options. The study aims to study and identify the contribution of renewable energy in the mixture of total energy supply in Libya. It also investigates the essential legislation in the field of energy, which contributes to supporting the expansion of the implementation of renewable energy as an alternative energy and proposing the necessary recommendations for the necessary investment. This study integrates data and information for literature review and secondary data from field visits to Libya to paint a comprehensive picture in relation to energy demand and consumption in Libya. Based on the literature review and secondary data, it is evident, despite the recent political changes in Libya that renewable energy is still strategically of high importance. Solar and wind energy a reconsidered the main sources of renewable energy in addition to wave and tidal energy. In addition, it has been found that energy demand is increasing in Libya and that renewable energy could be the solution to cover some of this demand. Moreover, there is a need to attract investors in renewable technologies by enhancing the infrastructure and the existing investment regulations.

http://www.thescipub.com/abstract/10.3844/erjsp.2013.15.23 2013/08/26 - 10:47

Manufacturing of polymer composites using plastic waste is one of the solutions to solve the environmental pollution problems caused by non-biodegradable polymer. In this study, Rice husk fiber Reinforced Polyethylene composites (RhRP) have been fabricated with rice husk fiber and plastic waste (recycle low density polyethylene) by compression molding method. Effect of fiber volume fraction, pressure and temperature on the properties of the composite samples was studied. In addition, mechanical properties, thermal properties and durability of RhRP composites were measured. Moreover, chemical modification of rice husk fiber was done through acid and aqueous alkaline solution. The modified fiber samples exhibit the higher strength as well as the lower water absorption rate compared with the unmodified fiber composite samples. Therefore, the resistance to aging of the composites in aqueous environment improved significantly for the modified composite samples. Furthermore, Scanning Electron Microscope (SEM) was also used to characterize the surface feature and the interfacial adhesion between fiber and matrix polymer. The modified composite samples reveal better interfacial adhesion than the unmodified composite ones. Thermo Gravimetric Analysis (TG/DTA) was employed to determine thermal stability of the composite samples. The modified fiber samples have higher thermal stability than the unmodified composite ones.

http://www.thescipub.com/abstract/10.3844/erjsp.2013.24.29 2013/08/26 - 10:47

Drying is an energy-intensive process. In general, heating and evaporation require large quantities of energy. This study has been conducted to evaluate analysis for dying apple slices in two drying systems including hot-air convection and infrared drying.The apple samples were dried at temperatures of 90, 120 and 150°C and radiation intensity of 0.22, 0.31 and 0.49 W/cm2 in the hot-air and infrared dryer, respectively. The results showed that the minimum energy consumed for drying apple slices in infrared dryer was 1 kW h while minimum energy consumption in hot air dryer was 7.02 kW h. Also, the specific energy consumption in IR dying was about 82-86% shorter than that of hot-air drying. The value of SEC of apple under IR and hot air drying was ranged from 110.35 to 71.78 kWh/kgwater and 635.53 to 501.15 kWh/Kgwater, respectively. The calculated value of moisture diffusivity varied from 3.499×10-7-4.746×10-7 m2/sec and 3.671×10-7-5.101×10-7 m2/sec and the value of energy activation were found to be 140.1 and 94.62 kJ moL-1 for IR and hot air drying, respectively. Therefore,one way to improve drying operations is to use infrared energy.

http://www.thescipub.com/abstract/10.3844/erjsp.2013.30.38 2013/08/26 - 10:47

In Thailand, the average wind speed throughout the country is comparatively low for normally-available wind turbine. Designing of a new blade suitable for applications in the average wind speed of 3-7 m sec-1 is, thus, a main objective of this study. High torque has to be obtained properly to generate electricity. In order to design and evaluate performance, our mechanical model has been developed based on Blade Element Momentum theory and, the model is consequently employed to determine the optimized blade shape under constrains that are rotor diameter of wind turbine is not higher than 3 m, design wind velocity is 6 m sec-1, 12 and 24 V battery chargers respectively. New wind turbine blade manually made from fiberglass (GRP) with safety factors of 4 (for 12 V battery) and 2.8 (for 24 V battery). Experimental study is conducted by testing both of commercial blades and our new blade with a specific wind turbine set. We found that, at designed wind velocity, the efficiency of our new wind turbine blade of 27% is obtained while that of the commercial wind turbine is only 16%.

http://www.thescipub.com/abstract/10.3844/erjsp.2012.52.58 2013/07/04 - 14:46

Known disadvantages of high-dense α-U metal fuel (intense radiation growth and radiation swelling, poor compatibility with steel claddings) can be reduced to the minimum by “constructive” approaches based on mechanical restraint of radiation growth and swelling and also on application of protective layers on fuel columns and claddings. Effectiveness of these methods has been confirmed during irradiation of full-sized fuel pins with high-dense metal fuel (γeff≥12.5g h.a./cm3) in the BOR-60 and BN-350 reactors.

http://www.thescipub.com/abstract/10.3844/erjsp.2012.45.51 2013/06/09 - 17:02

The aim of this work is to experimentally study, the effect of the heat recovery on water production in a solar desalination process that is working with multiple stage humidification technique. The water production, the temperature and the humidity were tested for such a pilot plant, which operates without and with a heat recovery system. The humidifier efficiency increases with the number of the operating heat exchangers and cannot normally exceed 45% when the system operates without heat exchangers. The air temperature in the heat exchangers decreases by 41.1, 39.2 and 36°C respectively when the system operates with three heat exchangers, tow heat exchangers in the and only one heat exchanger. The number of the heat exchanger use for heat recovery system in such desalination pilot plant has a significant influence on the water productivity. In short, results show that such a pilot plant working without the use of a heat recovery system (heat exchangers) is unable to deliver the desirable minimal amount distilled water at the exit of the condenser. Furthermore, the optimum number of heat exchangers that should be used to upgrade the overall efficiency of the desalination plant is two."

http://www.thescipub.com/abstract/10.3844/erjsp.2012.27.36 2013/03/12 - 22:03

Acceptance of renewable energy is influenced by attitude of the users towards new technology. Lack of research on renewable energy in emerging countries and drive for switching to alternative energy urge for studies on attitude of the users’ towards renewable energy adoption. This study investigates perception towards renewable energy use in Malaysia. A survey over 200 respondents from Klang-valley area was analysed using exploratory factor analysis and multiple regression analysis. Five factors emerged from factor analysis are relative advantage, perceived behavioural control, ease of use, awareness and benefit-cost trade-off. Multiple regression analysis was conducted to examine the explanatory power of these five factors while predicting intention to use renewable energy. The analysis showed that relative advantage and perceived behavioural controls positively mediate attitude towards renewable energy and attitude positively mediates intention to use. However, ease of use, benefit-cost trade-off and awareness positively but directly influence intention to use renewable energy. Study contributes to the literatures on social barriers of renewable energy in emerging nations and theory of planned behaviour. It contributes to existing policy initiative taken by government to enhance the use of renewable energy in Malaysia.

http://www.thescipub.com/abstract/10.3844/erjsp.2012.37.44 2013/03/12 - 22:03

The aim of this study is to evaluate the soil composition, the radioactive isotopes concentration and the outdoor air Kerma in the region of the Uraniferous Province of Lagoa Real, Bahia State, located at northeast of Brazil. It has used data from an airborne gamma-ray survey previously carried out in the region, namely Projeto Sao Timoteo and computer simulations of the soil and radiation transport by the Monte Carlo method. The simulation, considering environmental characteristics, mainly soil chemical composition and density, provide means to evaluate the air Kerma rate due to radionuclides present in the different types of soils. The evaluation was carried out considering the main contributors to the terrestrial natural radioactivity: 40K and the isotopes of the radioactive series of 238U and 232Th. In radiometric studies used to quantify exposure to natural radioactivity, a normal trend showed that regions with high values of the surface distribution of radionuclides had the highest values of air Kerma. The highest value was found for soil type LVe1 (146.40 nGy.h-1 average, ranging from 23.97 nGy.h-1 to 450.62 nGy.h-1), this type of soil and most of the anomalies located in this region, being rich in silica minerals, is of granitic rocks type.

http://www.thescipub.com/abstract/10.3844/erjsp.2012.20.26 2013/02/15 - 00:09

The reasons for implementing a high power density (>1 kW/m2) terrestrial rectenna for a space power plant system are described. The physical limitations on rectenna implementation are outlined and formal criteria for the rectenna site selection are proposed. The best site found was Mikura-jima, Japan.

http://www.thescipub.com/abstract/10.3844/erjsp.2012.12.19 2012/08/28 - 22:58

After reviewing the literature, we noticed that the vast majority of studies in the field of environmental accounting and disclosure have focused on developed countries such as Western Europe, America and Australia, while neglected developing countries. This study investigates the relationship between the level of environmental disclosure and company’s characteristics. The researchers identified a number of characteristics that associate with companies’ environmental disclosure, these are: Company’s size, company’s privatization, company’s age and company’s nationality. In the light of empirical results it is noticed that almost 100% of companies disclose some environmental information and they provide three types of environmental information good, neutral and bad news. In addition a significant positive association found between level of environmental disclosure and company’s size, company’s privatization and company’s nationality. Therefore it provide further evidence which emphasize that these characteristics are important elements and have an impact on the level and value of environmental disclosure. On the other hand it was found that age of company is insignificant and negatively related to the level of environmental disclosure.

http://www.thescipub.com/abstract/10.3844/erjsp.2012.1.11 2012/07/11 - 19:18

The designing of an automatic incubator consists of three main parts. The first part is a mathematical model of an incubator. Thermo-physical properties of selected materials were substituted to investigate its heat transfer characteristics. The second part is the consideration of equipment used to measure and control temperature and humidity. The last part is to select the controller for an inclined egg tray. In this study the incubator was designed to incubate 30 eggs each time. The dimension of incubator cabinet was 0.47×0.48×0.41 m. Within the incubator cabinet, the temperature of 37°C and humidity of 60% RH was set. Inside wall made from Zinc sheet and outside wall made from Acrylic plastic sheet. Insulation was plywood. Four lamps of 60 Watt halogen were selected as a heat source. Inside cabinet, two little fans were installed for air ventilation. An AP 104 board received input signals from thermocouple type K and connected to a relay. This board utilized for measuring and control temperature and humidity. To control the angle of the inclined egg tray, a limit switch was used. From testing the measuring and control system without egg, the results shown that measuring and control system gave high accuracy. From incubation experiments of the hatching eggs, the average of the chick biddy hatched 81.665%.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.51.56 2012/06/01 - 16:06

This study seeks to quantify and model the significance of the deepwater oil development for domestic US energy supplies in the short-term. It explores the significance and potential contribution deepwater oil supply from the Gulf of Mexico (GoM) can make in providing energy security to the US. The output of this research demonstrates the growth in deepwater oil production and how this latter relates to total US oil production over the next 10 years; and therefore the role it can play in providing energy security to the USA. The literature offers commercial and academic debate on this topic. The research model analyses current available data and make sensible assumptions on the likely future growth of deepwater oil production in the GoM based on a number of scenarios. Our results support the high/best case and suggest that deepwater oil from the GoM can significantly provide energy security to the US on the short term. However, on the long term and in order to maintain its energy security, the US needs to develop and use renewable sources of energy.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.38.50 2012/03/03 - 12:31

Problem statement: Perovskite lead zirconate exhibits in an orthorhombic formation at a temperature below the Curie temperature, TC. Approach: The orthorhombic is non-centrosymmetric which is capable of spontaneous polarization (electronic, ionic and orientation), depending on their composition and volume fraction. Results: The results from FTIR spectroscopy, XRD patterns, and SEM indicate that the lead zirconate particles are dispersed in Acrylic Rubber (AR72) matrix. At a small amount of lead zirconate particulates present in the AR72 matrix, at nearly 0.3986% V/V (AR72/PZ_5), the electrical conductivity increases dramatically by two orders of magnitude. Conclusion/Recommendations: Our synthetic Rubber (AR72)/lead Zirconate (PbZrO3) composite materials can be successfully used as the candidate materials of soft Electroactive (ER) actuators, sensors, artificial muscles, and smart engineering devices.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.34.37 2012/02/20 - 19:04

Mass attenuation coefficients of glass systems xPbO: 20Na2O: (80-x)B2O3 (x = 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 and 55% mol) were determined at 662 keV photon energy using gamma rays transmission method. The theoretical values of mass attenuation coefficients were calculated by WinXCom program. These coefficients were then used to determine the effective atomic numbers of glass samples. All shielding parameters were increased with increasing of PbO concentration. Our results have uncertainty less than 1% between experimental and theoretical values.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.29.33 2012/02/15 - 14:28

Problem statement: Assessment of the ground mass excavation is normally done by the deterministic method. A quantitative indication of mass stability provides as an index term known “the Factor of Safety (F.S.)”. There are uncertain to some degrees, such as only a single value of mass properties is used or variation in geologic conditions, computed values of F.S. are never absolutely precise. An alternative measurement of stability regarding use of index terms “Reliability (R) and probability of failure [p (f)]” is to cope with the uncertainty well. Concurrent processes of stability assessment are done using both the deterministic and reliability methods. Field data on the reliability approach assumed to be either normal function or lognormal function distribution. Conclusion/Recommendations: Three types of reliability model are proposed. Modeling types are based on the safety margin, the most likely value of F.S. and data simulation, respectively. These probabilistic values obtained from each model, are compared with the deterministic method. The risk on ground mass failures and environmental impacts due to excavation, be better defined and also achieved the optimized cost of construction excavation.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.17.21 2012/01/26 - 15:26

Problem statement: A brushless DC servomotor position control system using a fuzzy logic sliding mode model following controller or FLSMFC is presented. Approach: The FLSMFC structure consists of an integrator and variable structure system. Results: The integrator ensures the elimination of steady state error due to step and ramp command inputs, while the fuzzy control would maintain the insensitivity to parameter variation and disturbances. The FLSMFC strategy is implemented and applied to a position control of a brushless DC servomotor. Conclusion/Recommendations: Experimental results indicated that FLSMFC system performance with respect to the sensitivity to parameter variations is greatly reduced. Also, its can achieve a rather accurate servo tracking and avoids the chattering phenomenon.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.22.28 2012/01/26 - 15:26

Problem statement: Increasing air pollutions the big problem form internal combustion engines. Several attempts have been done to get a cleaner combustion process, one of which is the use of fuel ethanol in gasoline engines. Approach: The addition of ethanol in fuel will be change fuel properties. Results: To know the effect of fuel properties on engine performance and emissions produced, in this study was conducted tests against some root material, which is 95 octane gasoline, ethanol/gasoline 10, 20% ethanol, ethanol 30%, when the warm-up process. Conclusion/Recommendations: Result from this research, addition of ethanol in the fuel produces emissions of HC and CO is higher at the start, but with increasing time engine running the addition of ethanol to reduce emissions.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.1.5 2012/01/23 - 16:00

Problem statement: The energy demand in Thailand has significantly increased over last ten years, particularly in transportation sector. Road transportation contributes the highest energy consumption, 38% of the total energy in the whole country, but it consumes 60% of the total energy usage in the northern region of Thailand. Various chemical pollutants emitted from the road transportation affecting to human health and global warming situations. Approach: This study applied the system dynamics model to forecast the energy consumption and pollutant emission from the road transportation and to evaluate the policies in transportation management. The model integrates five related systems: (1) the socio-economic, (2) demographic, (3) land use, (4) transportation and (5) energy consumption and pollutant emission of vehicle. Data from 2002-2009 was collected and used to forecast the system from 2010-2030. The proposed model was applied to evaluate and compare five transportation policy scenarios including road expansion, public transit incentive, land use restriction, alternative vehicle (eco-car) promoting and alternative fuel promoting. Results: The both energy consumption and pollutant emission in the study area will increase substantially if no management plans are implemented. The energy consumption will increase from 958.2 kTOE in 2010-1,144.8 and 1,369.2 kTOE in 2020 and 2030. The pollutant emission will increase from 2.983 million MTCOE in 2010-3.497 and 4.182 million MTCOE in 2020 and 2030. Among five proposed scenarios, the public transit incentive policy maximizes the goal of energy conservation. It can save 730.21 kTOE and reduce 2.23 million MTCOE per year. Conclusion/Recommendation: The system dynamics modeling approach appropriates to simulate the trend of energy consumption and pollutant emission from the transportation sector. This application could be used as the tool for planning and management the transportation in context of the energy conservation and sustainably.

http://www.thescipub.com/abstract/10.3844/erjsp.2011.6.16 2012/01/23 - 16:00

Problem statement: The groundwater of Kathmandu Valley contained very high concentration of ammonia nitrogen which was in excess of WHO guideline value for drinking water. Approach: This study mainly focused on the removal of ammonia nitrogen in water by adsorption in locally available over burnt brick. The study was carried out in a 4.2 cm internal diameter column of 120 cm length packed with over burnt brick in up flow mode. Results: The study showed that the ammonia nitrogen removal rate increased with increase in contact time which decreased with time until steady state condition is attained. The contact time varied from 4-9.5 h for different particle sizes. Conclusion: The optimal value of adsorption rate constant was found as 0.1097 for particle size of 0.850-0.600 mm at corresponding contact time of 7 h. The adsorption data appears to fit the Freundlich’s isotherm. The fixed bed adsorption operation indicated that the ammonia nitrogen removal is the function of service time, bed depth and flow. Linear regression model showing correlation of these parameters has been developed.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.1.5 2011/01/11 - 03:52

Problem statement: Anaerobic digestion was a biological method used to convert organic wastes into biogas and a stable product for land application without adverse environmental effects. The biogas produced could be used as an alternative renewable energy source. The aim of this study was to analyze the influence of total solid contents on biogas yield from cattle manure using fluid rumen inoculums. Approach: A series of laboratory experiments using 400 mL biodigester were performed in batch operation mode. Given 100 g of fresh cattle manure was fed to each biodigester and mixed with fixed 50 mL of rumen fluid and different volumes of tap water resulting six different Total Solid (TS) contents i.e., 2.6, 4.6, 6.2, 7.4, 9.2, 12.3 and 18.4%. Results: The results showed that the best performance for biogas production was the digester with 7.4 and 9.2% of total solid i.e., gave biogas yield 184.09 and 186.28 mL gVSƒ{1, respectively after 90 days observation. While the other TSs content of 2.6, 4.6, 6.2, 12.3 and 18.4% gave the biogas yield 115.78, 122.33, 172.34, 137.99 and 54.87 mL gVS-1, respectively. Conclusion: These results suggested that, based on TS content effects to biogas yield, rumen fluid inoculum exhibit the similar effect with other inoculums. In all cases, there was no variation of pH, fat, protein and ash content in sludge after digestion at several variation of pH. During digesting, pH tends to increase to neutral pH i.e., optimum pH for methanogenic bacteria. The effect of rumen fluid concentration to biogas production will need to be studied in the next step research.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.6.11 2011/01/11 - 03:52

Problem statement: The purpose of this study is to design a renewable energy hydrogen based power system to provide electricity to a coastal residential area in east coast area (Kuala Terengganu) of Malaysia. Approach: The selected case study represents a power demand of 20 kWh day-1. The autonomous system used in this study is diesel generator, wind and photovoltaic hybrid system. The power system was redesigned and optimized as hydrogen-based autonomous power systems in order to meet the existing user’s power demand at a minimum cost of energy. Wind speed and solar radiations data obtained from Malaysian Meteorological Department have been used in the simulation process through optimization software, Hybrid Optimization Model for Electric Renewables (HOMER). Results: Three systems that were considered in this study area are stand alone PV-wind-diesel, stand alone PV-wind-hydrogen and grid connected PV-wind-hydrogen energy system. The proposed systems then were compared regarding on their operational characteristics and cost values. The comparisons prove that grid connected PV-wind-hydrogen energy system had the lowest total net present cost and cost of energy, $53,197 and $0.57/kWh, respectively that makes it the most cost effective system and followed by PV-wind-diesel and stand alone PV-wind-hydrogen system. Conclusion/Recommendations: It can be concluded that the hydrogen-based system can become a favorable system without aid from the grid system and bring advantage in technical and economic point of view and also suitable to be applied in the coastal residential application as energy carrier if only the current cost of wind turbine, PV arrays and hydrogen system technology have been reduced to its minimum rate.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.12.21 2011/01/11 - 03:52

Problem statement: The use of waste material is one of the options to add value to the residue. Nowadays, solid fuel development is necessary in current situation due to high price fossil fuel and the reduction of resource. Wood charcoal is widely used in the country which has abundant of forest. Becoming charcoal, it needs to be burnt under optimum condition. However, from this process the loss quality as in the form of breakage charcoal which is the blackish residue consisting of impure carbon is obtained. The price and utilization of this left are less benefit. Therefore, the improvement of charcoal residue by adding egg-shell powder is of interesting. The aim of this research is to study the feasibility of production of compressed charcoal mixed with egg-shell to extend the cooking temperature and time. Approach: Egg-shell was ground and pass through a sieve to get the different particle sizes. Three levels of particle sizes were achieved in the range of 300-600 microns (coarse), 150-300 microns (moderate) and less than 150 microns (fine). For the charcoal, it was obtained from the brakeage charcoal and ground to powder to be substance for making compressed charcoal. The ground charcoal was mixed with egg-shell powder at different ratios of 90:10, 85:15 and 80:20 by weight. The mixture was then compressed as a cylindrical shape by charcoal wet extruder. The formed charcoal was dried by open sun drying and was tested for compressive strength and water boiling. Results: The results showed that egg-shell powder enhanced the thermal property of charcoal regard to the results from water boiling. Conclusion/Recommendations: The best results of the highest compressive strength and the average water temperature were 89 kgf and 90°C for 45 min when application of coarse powder egg-shell at mixing ratio of 85:15.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.22.25 2011/01/11 - 03:52

Problem statement: Rice straw has been treated with different chemical (acid, alkali) and physical (subcritical water, ultrasound) methods to convert lignocellulose material to sugar. In addition enzyme treatment of pretreated samples has been applied to improve the conversion of lignocellulose material in sugar. Approach: Sulfuric acid at concentration of 1-9% was applied for acid treatment. For alkali treatment was sodium hydroxide solution at concentration of 1-5% used. Subcritical water treatment carried out at 160°C (5 bar) and 200°C (15 bar) for 10 min. Ultrasound was applied as combination method after acid pretreatment. The condition during ultrasound treatment was 40 W at 50°C and 10 min. Finally the pretreated sample was fermented using Saccharomyces cerevisiae yeast and the amount of produced ethanol was measured. Results: Acid treatment at 121°C, 15 min is an effective pretreatment method for converting lignocellulose to sugar. Up to 21.45% sugar w/w could be measure after acid treatment. Combination of chemical pretreatment and subsequent enzyme treatment increased the sugar yield drastically. Up to 37 and 28% sugar w/w could be achieved for acid and alkali pretreated samples respectively. Subcritical Water (SCW) treatment method is an effective physical method. SCW treatment at 200°C and 10 min followed by enzyme treatment yielded up to 17% sugar w/w. Combination of acid pretreatment with ultrasonic before enzyme treatment increased the conversion of lignocelluloses to sugar. Sugar yield up to 44% w/w after combination of acid and ultrasonic pretreatment and subsequent enzyme treatment could be achieved. Fermentation of pretreated rice straw shown that after 3 days fermentation most of sugar (55-65%) will be converted to bioethanol. The remaining sugar could not be converted in ethanol even after 6 days fermentation. Under these conditions, the maximum ethanol of 1.69% (v/v) was obtained. Conclusion: The combination method of acid pretreatment combined with ultrasound and subsequent enzyme treatment result the highest conversion of lignocelluse in rice straw to sugar and consequently, highest ethanol concentration after 6 days fermentation with S. cerevisae yeast.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.26.31 2011/01/11 - 03:52

Problem statement: The aim of this research is to determine the energy indices and to make a cost analysis of strawberry grown in open field in Kamyaran zone of Iran. Approach: The data used in the study were obtained from 35 local strawberry growers by using a face-to-face questionnaire in August-September 2009. Results: Total energy input for strawberry production was calculated to be 36822.9 MJ.ha-1. The Energy ratio was 0.48 and energy productivity was found to be 0.25 kg.MJ-1. About 74.5% of the total energy inputs used in strawberry production was non-renewable while only about 25.5% was renewable. The share of 56.6% of the total energy input was depended on the indirect form, whereas 43.4% of the total energy input was in the direct form. Specific energy was 3.96 MJ.kg-1. Economic analyses showed that profit/cost ratio and net profit were 1.49 and 4616.9 $.ha-1, respectively. Conclusion: The net energy in the study area was negative. This means that the amount of output energy is less than input energy and production in this situation is irrational, thus efficient use of resources and proper land management is needed.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.32.35 2011/01/11 - 03:52

Problem statement: Current researches had shown that the photostability of a luminescent solar collector depend on the method of its preparation and type of using dye. This research therefore aimed at studying the stability of luminescent solar collector prepared by sol-gel spin coating method using Ponceau 2R. Approach: The effect of silica matrix on the photostability and fluorescence properties of Ponceau 2R was investigated in terms of concentration using absorption and emission techniques. The photostability of Ponceau 2R doped sol-gel samples was also examined through 60 days exposure to sunlight. Results: The dye in the solid matrix had absorption and emission characteristics different from those in the liquid solution. The transition energy for electrons were direct allowed transition for all examined concentrations and there is no variation in the values of optical gap Energy (Eg) by increasing the dye content or exposure times. The dependence of the width of the tails of the localized states in the band gap (Eu) on the concentration and exposure times were also studied. The emission spectra for the samples before and after exposure to sunlight showed that the sample of concentration 0.1 wt% had the highest fluorescent intensity and fluorescence quantum yield. Conclusion/Recommendations: This study showed that Ponceau 2R of 0.1 wt% concentration has a good potential for application in a luminescent solar collector using sol-gel techniques.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.36.41 2011/01/11 - 03:52

Problem statement: A Closed-Loop Oscillating Heat-Pipe (CLOHP) heat exchanger was a heat exchanger with one of the most promising conductivity capacities because of its higher cooling and condensing potential. Therefore, the aims of this study were to design and fabricate a CLOHP to be applied to increasing oil yield in the pyrolysis process. Approach: Two types of oscillating heat-pipe arrangements-parallel and perpendicular to the gas flow direction-were compared with a conventional water-to-air condenser or glass-type heat exchanger. The oscillating heat-pipe was made of four sets of copper tubes working at 90° from the horizontal plane, with an inner diameter of 2.03 mm and a total length of 18 m. The number of turns was 15. The lengths of the evaporator and condenser sections were 50 and 100 mm in total, respectively. R123 was used as a working fluid, 50% by total volume. In the experiment, an air velocity of 0.4 m sec-1 was applied to the condenser section. 100 g of 5×5 mm pieces of motorcycle tire inner tubes were burned in a pyrolysis furnace of 500°C, having a heat-rate of 10°C min-1. Result: The results showed that a CLOHP parallel to the gas flow direction was more effective, resulting in 39.08 g crude oil from the hot gas in the pyrolysis process and a maximum heat flux of 1,181.53 W m-2. Conclusion: This study suggested that to improve the performance of a pyrolysis process which uses scrap motorcycle tire waste as a heating agent, a CLOHP should be placed in parallel to the gas flow line.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.42.46 2011/01/11 - 03:52

Problem statement: Cashew (Anacardium Occidentale L.) is one of the important tropical crops. India processed about 11,80,000 metric tons of raw cashew nut seeds through 3650 cashew processing industries scattered in many states of country. The cashew nut processing industries are typically located in the rural and backward areas. The most significant difficulty in processing cashew nuts is that the hard outer shell, which contains the edible kernel, contains a caustic oil which can burn the skin and produce noxious fumes when heated. More recently, smaller scale factories use the steaming and cutting method. Approach: At present cashew industries facing problem of interrupted power supply which affect the economical growth of the sector. The cashew industries in India employed different unit operations/methodology for processing depend on variety of raw material, location, technological mechanization, availability of secured energy supply. Results: Large disparities in energy intensity for similar process in the cashew processing reveal the scope for energy conservation to be in the order of 30-48%. There is good scope for effective utilization of solar energy and biomass gasification technology for energy generation in the sector. Conclusion: This study deled with the elucidation of the processing operations in the small-scale cashew processing of Maharashtra with identification of energy consumption for unit operations. The energy conservation opportunities in the cashew nut processing sector were discussed in the study. The scope for utilization of renewable energy technologies like solar dryers for drying of cashew nut seed and cashew kernel were elaborated. The characterization of cashew shell waste available in the processing industry revealed the scope for thermal gasification of shell for heat generation.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.47.50 2011/01/11 - 03:52

Problem statement: This research was conducted due to an increase of agricultural machinery cost for rice production (46.00%) of farmers in Phichit province. Based on an analysis of cost reduction using the method of John Deere, it was found that this may decrease from 46.00-28.50% of the total cost. Thus, there was a question how to mange the agricultural machinery. The objective of this research was to investigate the pattern of managerial administration of farming machinery for rice production, Phichit province. Approach: Research methodology in this research had many steps: In-depth interview with rice farmer members and farmer institution executives having good practice; an analysis of internal and external factors concerning about the managerial administration of rice farmer group; public hearing forum of stakeholders on rice farmer group management and the investigation of decision-making on the selection of management strategies. Descriptive statistics and Pearson co-efficient relation were used in this research. Results: Findings showed that there were four models of the managerial administration of agricultural machinery as follows: External hiring, co-investment, networking and participatory maintenance. For the management of farmer group, it should be in the form of networking connecting each sub-group. Also, it should have a coordination center for the planning of agricultural machinery, capital and welfare management. The management was dependent on three groups of strategies: (1) strategy a-the improvement of the managerial administration structure and grouping concept base; (2) strategy b-the development of potential and quality of the managerial administration and (3) strategy c-the creation of atmosphere in the participatory managerial administration of agricultural machinery, respectively. Conclusion: The implementation based on this model caused the farmers have confidence, unity and systematic working and power on the persuasions for group activity participation more than ever.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.51.54 2011/01/11 - 03:52

Problem statement: In this study, a combination of a classical Sliding Mode Control (SMC) and a PID tuning technique with low-pass filter is developed for a position tracking control of a DC servo motor. Approach: The DC servo motor will be used to adjust the throttle angle of the gasoline engine in our laboratory. To control the engine speed to be accurate, the servo motor position has to be controlled precisely. Results: Uncertainty and nonlinearity of the servo motor system can be surmounted by the sliding mode control while the system response can be fine adjusted via the PID gain tuning. A low-pass filter has been incorporated also in order to eliminate and limit amplification of noise due to differentiation in the PID algorithm. The stability of the control system is guaranteed by the Lyapunov stability theorem. The experimental results shown that, the proposed technique has good tracking performance compares to a PIDSMC and a conventional PID technique even without actuator model. Conclusion/Recommendations: However, the performance strongly depends on the specified control gain in PID portion and sliding function. Therefore, any self tuning control gain techniques should be developed further.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.55.61 2011/01/11 - 03:52

Problem statement: While classical PID controllers are sensitive to variations in the system parameters, Fuzzy controllers do not need precise information about the system variables in order to be effective. However, PID controllers are better able to control and minimize the steady state error of the system. To enhance the controller performance, hybridization of these two controller structures comes to one mind immediately to exploit the beneficial sides of both categories. Approach: A hybrid fuzzy PID controller for the Electro-Hydraulic Position Servo System (EHPSS) was proposed in this study. The proposed control scheme was separated into two parts, fuzzy controller and PID controller. Fuzzy controller was used to control the piston when the piston locates far away from the target position. PID controller is applied when the piston is near the desired position. Results: We demonstrated the performance of control scheme via experiments performed on the EHPSS. Conclusion: The results from the experiments showed that the proposed hybrid fuzzy PID controller has superior performance compared to individual PID controller and fuzzy controller.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.62.67 2011/01/11 - 03:52

Problem statement: Current researches have shown that the thermoplastic-clay nanocomposites have failed to live up to the earlier predictions albeit they have found some niche area of applications. This research work therefore aimed at studying the effect of carbon nanotube as secondary filler on the mechanical properties of polypropylene-clay nanocomposite. Approach: Hybrid polypropylene-clay nanocomposite was prepared in the presence of Multiwall Carbon Nanotubes (MWCNTs) as secondary additives using melt intercalation process. The effect of Multiwall Carbon Nanotubes (MWCNTs) on the polypropylene/clay matrix was investigated in terms of dispersion using XRD, tensile test (ASTM D 638) and notched Izod impact test (ASTM D256). These were compared with the conventional polypropylene-clay nanocomposite. Results: The resulting composite shows about 42% increase in the modulus, 26.20% in the tensile strength and 13.30 Kj m-2 impact strength when compared with binary combination of PP/Clay nanocomposite. XRD patterns of PP/Clay and PP/Clay/MWCNT nanocomposites show different diffraction peaks which are indications of intercalation mixed with macromixing. Conclusion: This study showed that MWCNT can successfully address the common shortcomings peculiar to PP/Clay nanocomposite.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.68.72 2011/01/11 - 03:52

Problem statement: Titanium dioxide is a well known material using with self-cleaning application. This is due to its properties after exposed to UV light: Superhydrophilicity and photocatalysis. The addition of other oxides could prolong these properties without continuing exposed to UV. However, titanium dioxide phase is essential. In order to obtain these properties, titanium dioxide needs to be in anatase phase. Approach: In this Research, phase transformation temperatures of mixed oxide of titanium dioxide and other oxides were determined. Samples of different mixed oxides were prepared by sol gel method. The first sample contained 30%TiO2 and 70%SiO2. The second sample contained 30%TiO2, 15%CeO2 and 55%SiO2. The last sample contained 30%TiO2, 15%CeO2 and 55%SiO2. Each sample was separately calcined at various temperatures from 350-850°C stepping by 50°C and followed by grinding and sieving to obtain in the form of powders. Then, each powder was characterized for its microstructure and phases of titanium dioxide, crystallite size by X-Ray diffraction. Results: The results from XRD showed that for a 30%TiO2/SiO2, an increase in calcined temperatures from 350-850°C (increasing by 50°C) increased average crystallite sizes of titanium dioxide (from 5.1-11.8 nm). Also, titanium dioxide phase found in the samples was only anatase. For a 30%TiO2/15%CeO2/SiO2, an increase in calcined temperatures was not affect to the structure of the samples and XRD patterns seemed to be in an amorphous structure. Finally, for a 30%TiO2/15%AgO/SiO2, titanium dioxide was found in an anatase phase at 350°C until 650°C. Then, at calcined temperatures greater than 700°C, rutile phase started appearing in the structure while anatase phase peaks slowly declined with an increasing in calcined temperatures. This result showed that using these mixed oxides to coat over glass slides or mirrors for self-cleaning purposes, the films should be treated at certain temperatures to obtain an anatase phase. Conclusion: Phase transformation of titanium dioxide depends on calcined temperatures. The addition of other oxides such as silica, cerium or silver can effectively suppress the anatase-rutile phase transformation and resulted in an increase of anatase-rutile phase transformation temperatures.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.73.77 2011/01/11 - 03:52

Problem statement: The removal of heavy metals contaminated in aqueous solution/wastewater has been causing worldwide concern. However, the adsorbent materials are usually limited due to their high cost and environmentally benign. To overcome the above-mentioned disadvantages, low-cost and effective adsorbents are in demand. Approach: In this study, the sea mussel shells/natural clay beads were prepared for using as low-cost sorbent to remove Cd in the synthetic wastewater. Results: The sorbent were characterized using Scanning Electron Microscopy (SEM). The adsorption of Cd(II) ions from aqueous solution onto adsorbent has been investigated using kinetic approach to evaluate the effect of initial concentration and contact time on the removal of Cd. In adsorption studies, residual Cd(II) ion concentration reached equilibrium in duration of 240 min for initial Cd concentration of 5 ppm. The maximum removal achieves 99.75 mg g-1. Conclusion/Recommendations: The present results suggest that the adsorbent derived from sea mussel shells/natural clay bead is expected to be an economical material for removal of Cd(II) ions effectively from contaminated water.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.78.81 2011/01/11 - 03:52

Problem statement: Currently, in order to suppress intermetallic reaction layer formation during dissimilar metals welding between steel/aluminum alloy, only laser beam welding as self-brazing technique has been applied. However, TIG welding process might be one of welding process candidate for joining dissimilar metals welding between steel/aluminum alloys due to its capability in joining thin section. In the present study, the feasibility of application of TIG welding process in joining dissimilar metals between steel/aluminum alloy was evaluated. Approach: In order to realize the feasibility of TIG welding process, bead on the steel sheet experiment and dissimilar metals welding experiment was carried out. Results: From bead on the steel sheet experimental results, TIG welding could produce the partial penetration welding in 1 mm thickness steel sheet. In dissimilar metals welding experiment, TIG welding process as a self-brazing technique could successfully join dissimilar metal between steel and aluminum alloy. Moreover, the load resistance of bonded zone of dissimilar metals joints was higher than the load resistance of A1100 aluminum alloy after welding. Conclusion: These results indicated that TIG welding process is feasible to be dissimilar metals welding candidate for joining steel/aluminum alloy.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.82.86 2011/01/11 - 03:52

Problem statement: Electrical Discharge Machining (EDM) is now a well-established machining option in many industries. Tungsten carbide (WC-Co) is an important tool and die material mainly because of its high hardness, strength, wear resistance and high melting point. Normally, EDM is capable of machining geometrically complex or hard material component, that are precise and difficult to machine. The objective of this research is to study the performance of different electrode materials on tungsten carbide workpiece with EDM process. Approach: The electrode materials were graphite (Poco EDM-3), copper-graphite (Poco EDM-C3) and copper-tungsten (solid).The important parameters were discharge current, on time, off time, open-circuit voltage and electrode polarity. A workpiece material was a tungsten carbide (W 90-Co10). Results: The results show that the electrode negative polarity performs very well, Poco EDM-3 gives higher Material Removal Rate (MRR). Both powder electrode (EDM-3 and EDM-C3) give the better MRR and EWR more than solid electrode. Conclusion: The suitable duty factor is 11%. The Surface Roughness (SR) of copper-tungsten give the best when current peak intensity not over 20 amperes.

http://www.thescipub.com/abstract/10.3844/erjsp.2010.87.90 2011/01/11 - 03:52