Articles

  1. MODELING OF PERMEABILITY OF POROUS MEDIA WITH MIXED WETTABILITIES BASED ON NONCIRCULAR CAPILLARIES Download Article

    Junichiro Takeuchi, Hidetaka Tsuji and Masayuki Fujihara
    • Article Type: Research Article
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    • Pages (1-7)
    • No of Download = 614

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    Hydraulic conductivity of hydrophobic porous media is greater than that of hydrophilic porous media under the same saturation condition. One of the reasons for this is that the size of the pores filled by water in hydrophobic porous media is greater than that in hydrophilic media under unsaturated conditions. The validity of this phenomenon was ascertained through numerical experiments using a pore-network model. However, the pore-network model with circular tubes could not account for the phenomena sufficiently. Then, noncircular tubes are employed to take air-water interfaces formed at gaps between grains into account. In one case of hydrophobic grains, water cannot occupy corners and flows in the center of capillary tubes. In the other case of hydrophilic grains, water invades the corners first and flows through the corner filaments until water enters the tube completely. In this study, equilateral triangular and cuspate cross-sections are used, and the relation between the flow resistance of the tube, which is separated into shape and scale factors, and capillary pressure is investigated. The computed results show that the flow resistance of center flows could become smaller than that of full flow and that it leads to higher hydraulic conductivity of hydrophobic porous media.

  2. ENVIRONMENTAL IMPACTS OF RECYCLED NONMETALLIC FRACTION FROM WASTE PRINTED CIRCUIT BOARD Download Article

    Suphaphat Kwonpongsagoon, Sawanya Jareemit and Premrudee Kanchanapiya
    • Article Type: Research Article
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    • Pages (8-14)
    • No of Download = 613

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    Recently in Thailand, the recycling process of waste printed circuit board (WPCB) has retained a large volume of nonmetallic fraction (NMF), which has entered the industrial waste stream and awaits an appropriate treatment to be suggested. The aim of this paper was to assess environmental impacts of the recycled nonmetallic fraction from waste printed circuit board in Thailand, using the ReCiPe midpoint assessment method of life cycle assessment approach. For this purpose, one of the glass fiber reinforced plastic (GFRP) manufacturers in Thailand was selected to obtain data for NMF waste and the production of two new recycled NMF products. The environmental impacts of two new recycled NMF products compared with traditional GFRP product, and two recycled NMF products compared with conventional waste disposal methods by means of landfilling and incineration were considered. The result showed that the potential environmental impacts were in the damage categories of climate change, human toxicity, marine ecotoxicity, and fossil depletion. For overall comparison, the recycled NMF as a modified GFRP product (recycled product 1) showed the worst impacts to human toxicity, marine ecotoxicity, and fossil depletion categories compared with other methods because of the complex production technique and the chemical-based process. Moreover, the recycling of NMF as a new product (recycled product 2) is likely to be the most suitable waste management option in Thailand.

  3. EFFECTS OF BEND-TWIST COUPLING DEFORMATION ON THE AERODYNAMIC PERFORMANCE OF A WIND TURBINE BLADE Download Article

    Nawapon Sompong and Pongtorn Prombut
    • Article Type: Research Article
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    • Pages (15-20)
    • No of Download = 960

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    Comprehensive research exists on passive pitch control of wind turbines using bend-twist coupling property of composite materials. Blades with bend-twist coupling deformation can increase energy capture, improve dynamic stability, or reduce aerodynamic loads. The objectives of this work are to apply bend-twist coupling into an existing blade design and to investigate the resulting aerodynamic performance. The 41.25-meter blade was based on GE 1.5 GLX wind turbine. Aerodynamic loads were calculated using Blade Element Momentum (BEM) theory and Computational Fluid Dynamics (CFD) simulation. The resultant thrust and torque from both methods agree well. However, only the CFD can provide details of pressure distribution over the complex blade surface. Three levels of bend-twist coupling were designed for the Glass/Epoxy blade skins i.e. no coupling, low coupling, and high coupling. From Finite Element Analysis (FEA), the deflections of the three blades were slightly different while the twist angles were considerably different. The deformed geometries of the blades were then used to produce new three dimensional (3D) models for the prediction of the power coefficient (CP) by CFD. The results show that the proper bend-twist coupling laminate can improve the performance of the blade. At low wind speed, the CP is higher than the baseline blade. At wind speed greater than rated speed, however, the blades twist two much and the CP decreases below the baseline blade. Simulation of 3D blade models can help in the design of a bend-twist coupling level suitable to the blade shape and wind speed.

  4. NUMERICAL INVESTIGATION FOR THE ENHANCEMENT OF THE AERODYNAMIC CHARACTERISTICS OF AN AEROFOIL BY USING A GURNEY FLAP Download Article

    Julanda Al-Mawali and Sam M Dakka
    • Article Type: Research Article
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    • Pages (21-27)
    • No of Download = 570

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    Numerical investigation was carried out to determine the effect of a Gurney Flap on NACA 0012 aerofoil performance with emphasis on Unmanned Air Vehicles applications. The study examined different configurations of Gurney Flaps at high Reynolds number of 3.6×105 in order to determinethe optimal configuration. The Gurney flap was tested at different heights, locations and mounting angles. Compared to the clean aerofoil, the study found that adding the Gurney Flap increased the maximum lift coefficient by19%, 22%, 28%, 40% and 45% for the Gurney Flap height of 1%C, 1.5%C, 2%C, 3%C and 4%C respectively, C represents the chord of the aerofoil. However, it was also found that increasing the height of the gurney beyond 2%C leads to a decrease in the overall performance of the aerofoil due to the significant increase in drag penalty. Thus, the optimal height of the Gurney flap for the NACA 0012 aerofoil was found to be 2%C as it improves the overall performance of the aerofoil by 21%. As for the location, it was found that the lifting-enhanced effect of the gurney flap decreases as it is shifted towards the leading edge. Thus the optimal location of the Gurney Flap mounting was found to be at the trailing edge or at distances smaller than 10%C. The Gurney flap was also tested at different mounting angles of -45, 90 and +45 degrees and it was found that the Gurney flap at +45 mounting angle leads to the optimal performance of the aerofoil.

  5. DC AND RF CHARACTERISTICS FLUCTUATION OF INALAS/INGAAS HEMTS ACCORDING TO THE OPERATING TEMPERATURE VARIATION Download Article

    Kenta Otsuki, Yuta Kainuma, Ryuichi Miyashita, Kimihiro Yamanaka and Hirohisa Taguchi
    • Article Type: Research Article
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    • Pages (28-31)
    • No of Download = 656

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    InAlAs/InGaAs high electron mobility transistors (HEMTs) are a type of field effect transistor that can achieve extremely high high-frequency gain owing to quantum effects operating in the channel layer. HEMTs are important components for devices that involve millimeter waves and high-speed optical transmission systems. However, InAlAs/InGaAs HEMTs have a frequency dispersion that depends on carrier recombination within the device. This is an InGaAs-specific phenomenon, which degrades the device’s high-frequency gain performance. In this study, we investigated the direct current (DC) and radio frequency (RF) characteristics of InAlAs/InGaAs HEMTs by varying the operating temperature from liquid nitrogen temperature to 125 °C. The DC characteristics showed an increase of the device transconductance (Gm) at low temperature. Reducing the operating temperature from 125 °C to liquid nitrogen temperature increased Gm to 60 mS. High-frequency gain was also confirmed in the RF characteristics. The current gain cutoff frequency was 50.2 GHz at room temperature, and 66.8 GHz at liquid nitrogen temperature, representing an increase of 33.1%. Analyzing the high-frequency characteristics showed that the high-frequency gain increase at low temperature was related to the temperature dependence of the parasitic capacitance.

  6. SHEAR ZONE DEVELOPMENT AND FRICTIONAL INSTABILITY OF FAULT GOUGE Download Article

    Momoko Hirata, Jun Muto and Hiroyuki Nagahama
    • Article Type: Research Article
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    • Pages (32-37)
    • No of Download = 750

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    Earthquakes are typical phenomena of frictional slip of geomaterials in nature. To evaluate slip instability, shear development in a gouge layer or fault material has been investigated. However, the quantitative relationship between slip instability and shear development has not been revealed because of difficulty in quantitative observation of microstructures under high pressure. Hence, we aim to describe shear development in a gouge layer energetically, and discuss the relation between shear development and slip instability. To this end, we calculated shear angles by utilizing experimental data of gouge. As a result, this study reveals that shear bands in a gouge layer develop at lower angles or almost parallel to rock-gouge boundaries toward the occurrence of unstable slip, particularly under low confining pressure. Additionally, variation in Riedel shear angles throughout gouge layers depends on confining pressures: Under low confining pressures, heterogeneous localized shears trigger voluntary increase in strain. On the other hand, under a high confining pressure, gouge layers deform homogeneously, and the whole of samples slips dynamically. Clarification of shear development of geomaterials is useful for evaluating the occurrence of frictional slip such as earthquakes and slope failures.

  7. STUDY ON ADSORPTION ABILITY OF ADSORBENTS FOR STRONTIUM IN DIFFERENT SOLUTIONS Download Article

    Keiichiro Shibata, Hidenori Yoshida, Naomichi Matsumto and Yoshihiro Suenaga
    • Article Type: Research Article
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    • Pages (38-44)
    • No of Download = 697

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    The Tsunami due to the Great East Japan Earthquake on March 11, 2011 indirectly caused a nuclear disaster at the Fukushima Daiichi nuclear energy plant of the Tokyo Electric Power Company. The radioactive strontium dispersed by the accident has spread to the soil, lake, river and marine environments. In addition, contaminated groundwater continues to be generated by the flow under the damaged facilities of the plant. The increase of collected tainted water makes it difficult to secure the storage facility. In the face of such situation, the decontamination work for the radioactive strontium has not been completed. It is possible that humans may be exposed as a result of transfer through the food chain and biomagnification when the tainted water, including the major quantity of strontium leak to the marine environment. Therefore, the decontamination of strontium is an urgent requirement. To help address this risk, we previously conducted an experiment to sequester strontium into an adsorbent so as to decrease the degree of contamination. The results of this earlier study confirmed that the uptake ability of adsorbent for strontium varied in different solutions. In this study, the adsorption test of adsorbent is conducted to understand its ability in solution composed of magnesium, potassium or chloride. The hydroxyapatite derived from fish bones is developed and used as the adsorbent. From the result of tests, it is confirmed that the adsorption ability of the hydroxyapatite for divalent cation is high in the various solutions.

  8. INVESTIGATION ON THE BIODEGRADATION CAPACITY OF URBAN RIVERS IN JAKARTA, INDONESIA Download Article

    Yonik Meilawati Yustiani and Imas Komariah
    • Article Type: Research Article
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    • Pages (45-50)
    • No of Download = 754

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    Jakarta is a city with dense population and various activities causing the heavy pressure to the environment. Domestic and non-domestic activities are generating pollution to its rivers. The water body actually has itself a self natural purification capability. The characteristic of the river water quality will affect this pollution degradation process. This research is conducted to examine the biodegradation capacity of Jakarta’s rivers. Water quality data of 23 rivers were collected for the time period of 2011 to 2015. Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) concentrations are then being used to calculate the BOD/COD ratio. The calculation results show that during the period time of 2011-2013 the ratio ranges between 0.36 and 0.63, which indicates that the rivers have average biodegradation capability. However, the 2014 year’s data show that almost all of the rivers have ratio less than 0.2, indicating the no-biodegradation capability. Existence of metals can also inhibit the biodegradation process. The water quality data shows significant increase of metals in the year of 2014, especially Copper and Zinc in several rivers. Surfactant was also observed in extremely high concentration. Thus, most of the Jakarta’s rivers have relatively low capability in biodegradation capacity and self purification capability. Although the latest year data shows an improvement, yet the BOD/COD ratio is still in the range of slow of biodegradation capacity.

  9. CHARACTERISTICS OF THE SLUDGE PARTICLES IN REMOVAL PROCESS OF RADIOACTIVE CESIUM FROM OCEAN SLUDGE BY DECOMPOSITION SYSTEM WITH CIRCULATION TYPE USING MICRO BUBBLES AND ACTIVATING MICROORGANISMS Download Article

    Kyoichi Okamoto, Takeshi Toyama and Tomoe Komoriya
    • Article Type: Research Article
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    • Pages (51-56)
    • No of Download = 612

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    The Fukushima nuclear accident of March 11, 2011, soil and water had been contaminated by radioactive cesium. Moreover, radioactive cesium was found in the ocean sludge in Tokyo Bay flowing from rivers. Cesium which is adsorbed to the sludge cannot be easily removed. One of the authors developed decomposition and purification system, a circulation-type system by micro bubbles, that is, by creating aerobic state, aerobic bacteria are activated resulting to decomposition and purification of ocean sludge. Based on the hypothesis that radioactive cesium is adsorbed on the surface of the sludge deposition. It is considered cesium can be eluted after decomposing the deposited sludge. Once the cesium is eluted in the water, it can fix to a mineral such as zeolite. Now we need the properties of sludge in removal process by decomposition system with circulation type. In this study, our objects is to check the characteristics of the sludge particle in removal process of radioactive cesium from ocean sludge by decomposition system with circulation type using micro bubbles and activating microorganisms. As the results of this experiments, we had very good purification ratio on total nitrogen and had made 40 times of smaller size on diameter of the particle of sludge.

  10. A TURBIDITY REMOVAL STRATEGY FROM THE WATER RESOURCES OF BANDUNG CITY, INDONESIA Download Article

    Evi Afiatun, Hary Pradiko and Hari Prayoga
    • Article Type: Research Article
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    • Pages (57-61)
    • No of Download = 454

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    Cikapundung and Cisangkuy River are the sources of raw water used by Bandung City. The special characteristics of these water resources are the fluctuations of flow and turbidity in the dry season and the rainy season with the highest turbidity > 600 NTU. The turbidity fluctuation is not significantly followed by the coagulant dose changes. This research was conducted in order to evaluate and strategize the optimal performance of the water treatment plant based on the evaluation of the processed water. The laboratory analysis was carried out to find the dominant parameters, namely turbidity, with the steps such as 1) comparing the coagulation process that has been or has not been through preliminary sedimentation using coagulant polyaluminium Chloride (PAC); 2) observing the stability and efficiency of sediment that resulted by coagulation process for the several variation of time; 3) analyzing the efficiency of the preliminary sedimentation and coagulation process. The results of laboratory analysis show that the optimum time of the deposition processes is 35 minutes with a decrease in turbidity of about > 80%. The highest efficiency of sedimentation processes occur at the initial turbidity of 514 NTU in the amount of 85.02%. The optimum coagulant dosage without using the preliminary sedimentation is reached at initial turbidity of 147 NTU with an efficiency of 99.76%; while those using the preliminary sedimentation are achieved at initial turbidity of 514 NTU with an efficiency of 99.46%. Based on these analyses, it is necessary to adjust the operational process of preliminary sedimentation.

  11. A STUDY ON THE COOLING EFFECTS OF GREENING FOR IMPROVING THE OUTDOOR THERMAL ENVIRONMENT IN PENANG, MALAYSIA Download Article

    Julia Md. Tukiran, Jamel Ariffin and Abdul Naser Abdul Ghani
    • Article Type: Research Article
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    • Pages (62-70)
    • No of Download = 615

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    Shade tree coverage and reflective pavements are useful mitigation strategies to help cool the air and provide shade. It also helps to lower building energy consumption by providing better outdoor boundary conditions. This study presents a simulation approach to evaluate and determine the cooling effect of greening modification developments of a study area on the surrounding environment. This study presents two approaches, including an on-site measurement and a numerical simulation model that uses ENVI-met V 4.0 BETA. Five scenarios with different types of tree coverage and density canopy by adding reflective pavements at ground surface are used. This study was conducted at the RST Complex of Universiti Sains Malaysia. The simulation results showed significantly lower air temperatures in three greening scenarios compared to the current condition scenario with 10% tree coverage. Increasing 20% of tree coverage with less dense and high dense of canopy in the study area led to a maximum air temperature reduction of up to 0.97 °C and 1.15 °C, respectively. Meanwhile, increasing 20% tree coverage with a highly dense canopy and applying reflective pavements on the ground surface contributed to a maximum air temperature reduction of up to 1.16 °C. The outcome of this study could be used to help urban planners and designers to select strategies for designing outdoor spaces to relieve heat stress with the main aim of improving the outdoor living environment.

  12. THE POTENTIAL OF INDIGENOUS BACTERIA TO INCREASE POROSITY-PERMEABILITY OF RESERVOIR ROCK: A PRELIMINARY STUDY Download Article

    Astri Rinanti
    • Article Type: Research Article
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    • Pages (71-75)
    • No of Download = 404

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    Oil content extraction from the rock pores can be very complicated due to the high viscosity of petroleum oil and low degree of reservoir rock porosity as well as its permeability. A research had been carried out with the use of mix populations of indigenous bacteria isolated from formation water (fw), well-site sludge (ws) and well mud (wd). Limestones was used as samples. This cores were soaked for 2 (two) weeks in 550C, a media contained of 1% molasse dissolved in sterillized formation water and 20% crude oil as covering. During the research, there was a change in the pH environment from neutral to acid. Acid production from the reaction result with carbonate in the solution will lower pH of the water that was produced. Changing value of porosity (%) that was injected by bacteria from fw, ws, and wd, increases respectively 23.22, 68.29, 14.89, and changing value of permeability (%) respectively 56.28, 137.83, 35.77. Even though on average there were an increase in value of porosity and permeability, there were also a decrease in the value of porosity and permeability of a few of the limestones samples. Inoculum bacteria from the pollution around the oil well are much more adaptive and give more carbonate dissolving reaction than the other actions. MEOR (microbial enhanced oil recovery) technique is really dependent on the growth of the microbes in site, and the development of the secondary metabolit products that can change the porosity and permeability of the reservoir limestones.

  13. A SIMPLIFIED METHOD FOR LABORATORY SOIL ANALYSIS Download Article

    N. Chaouqi, M.El Gharous, Z.Naceri and M.Bouzziri
    • Article Type: Research Article
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    • Pages (76-81)
    • No of Download = 768

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    The research goal was to develop a simplified method for estimating the available phosphorus for routine analysis. This study compared the measured Soil-P using the ICP-NaHCO3 with the simplified extraction method (SM-P). The correlation (r=0.99) and the regression(using XLSTAT-Pro) were employed for comparing the data of available phosphorus content in soil samples for a variety of Moroccan soil types, with contrasted physicochemical characteristics: Ali Moumen, Oued Qibane, Ouled Said, Dower Hbata, Dower Lhfaya, and Had Ghoualem (are located using ArcGIS 10.1 and fertiMap). SM-P is most suited for soils with pH >= 7 and CaCO3 content above 5%. In this experiment, several parameters are modified, particle size, the type and degree of mechanical agitation ,the color development solution ([(NH4)6Mo7O24.4H2O]&[ K(SbO), C4H4O6,5H2O],1 %(w/v) (C6H8O6) ), and the adaptation of the reading at 860 nm, are improving the accuracy of P analysis, the high correlation of this method with ICP-NaHCO3 content can be an indication for it. The results of this experiment showed that SM-P can be the best method for predicting the available phosphorus, simple, quick, and easy to execute.

  14. THE DISTRIBUTION AND ACCUMULATION OF CHEMICAL ELEMENTS IN THE ECOSYSTEM OF LAKE ILMENSKOE Download Article

    Tatyana G. Krupnova, Irina V. Mashkova, Anastasiya M. Kostryukova and Egor V. Artyukov
    • Article Type: Research Article
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    • Pages (82-88)
    • No of Download = 654

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    In the present study Mg, Al, Si, P, S, Cl, K, Ca, Mn, Fe, Zn, Ag, Sr contents were determined by X-ray fluorescence analysis in sediments and organisms of Contectiana listeri and Potamogeton lucens L. of Lake Ilmenskoe located on the territory of the Ilmen State Reserve (South Ural, Russia). It was shown that microelements-rich sapropels are formed in the Lake Ilmenskoe. The Lake Ilmenskoe is free of anthropogenic impact and may be regarded as models while assessing the lakes under anthropogenic impact. The average element composition of macrophytes, gastropod shells and muscles, sapropel and sandy sediment were compared with the clarkes of elements in the continental crust with a preliminary aluminium rating, aluminium being the least fluent and abiogenic element of the system ‘sediment – hydrobiont’. Sapropel was particular rich in microelements in comparison with sandy sediments. Study is shown that most elements are accumulated in aquatic organisms. Contectiana listeri and Potamogeton lucens L. may be considered as geochemical barriers. They can be used as biomonitors. We found out that low-iron, low-calcium, low-ash sapropel was forming in Lake Ilmenskoe.

  15. ECOLOGICAL STATE AND NEW APPROACHES TO THE RESTORATION OF LAKE UVILDY, RUSSIA Download Article

    Irina V. Mashkova, Tatyana G. Krupnova, Anastasiya M. Kostryukova and Varvara Yu. Schelkanova
    • Article Type: Research Article
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    • Pages (89-95)
    • No of Download = 693

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    Lake Uvildy is situated in the North of Chelyabinsk region. Lake Uvildy is one of the largest and the most unique of South Ural’s lakes. In 1975–1977 the drought occurred and water supplies dried up in South Ural. 234 million cubic meters were moved from the Uvildy lake in Argazi reservoir, which was a source of water supply of the Chelyabinsk city. The lake’s water level fell by more than 4 meters. Only in 2008 the water level returned to the previous position, but riparian vegetation was flooded. In July 2014 we carried out an ecological survey of the lake in five sites. We discovered submerged tree and shrub vegetation at 50–70 meters from the bank. Chemical analysis of water revealed the accumulation of organic substances and the transition of nitrogen from nitrate to nitrite and ammonia, of sulfur from sulfate to sulfite and hydrogen sulphide, of carbon to methane. We found blue-green algae (Microcystis, Anabaena, Oscillatoria) in all the sites. It indicates the beginning of water eutrophication. We proposed a new method of ecological restoration of the lake. In August 2014 we cleaned the bottom of the lake in two research points with a special innovative bottom-cleaning machine working both as a pump and a crusher. The research in summer 2015 showed that the water quality had significantly improved and the process of eutrophication had stopped in the points where the bottom was cleaned. Works on the lake trophicity will be continued.

  16. SOCIO-ENVIRONMENTAL DIMENSIONS OF TOURIST SERVICE EXPERIENCE IN HOMESTAYS Download Article

    Boo Ho Voon, Jamil Hamali, Patricia Melvin Jussem, Ai Kiat Teo and Agnes Kanyan
    • Article Type: Research Article
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    • Pages (96-100)
    • No of Download = 761

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    Homestay tourism can be a lucrative service sector and the Culture, adventure and nature (CAN) have been recognized as the critical components of eco-tourism products for tourism-friendly nations like Malaysia. Many tourists have enjoyed the social and environmental aspects of the various tourist destinations and there are also tourists who are not very happy with certain aspects of their experiences. This research investigated the tourists’ experiences with the homestay programmes using qualitative and quantitative techniques, namely the focus groups and questionnaire survey to discover their experiences and thereafter developed a multi-item measurement. Responses of 330 sampled respondents were analyzed. A total of nine dimensions were found and the measurement fit indices of these socio-environmental measurement was satisfactory. The socio-environmental issues included culture, guiding, accommodation, services, food and beverages, journey, natural environment, access and cleanliness. The homestay service environment indeed must be holistic and sustainable to create the memorable and delightful tourist experience which can generate more income and other benefits for the stakeholders. Implications and future research were also discussed for continuous improvement of the environment-driven performance measurement and management process.

  17. MONITORING AIR QUALITY USING LICHENS IN CHELYABINSK, RUSSIAN FEDERATION Download Article

    Anastasiya M. Kostryukova, Tatyana G. Krupnova, Irina V. Mashkova and Elena E. Schelkanova
    • Article Type: Research Article
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    • Pages (101-106)
    • No of Download = 525

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    Air pollution in large cities is one of the most serious ecological problems, because emissions always go into the atmosphere. One of the specific methods of pollution monitoring is lichen indication. The aim of the study is to evaluate the quality of the atmospheric air of Chelyabinsk city (Russian Federation). The results were obtained from samples collected in June-July 2015. The trees for the lichen sampling were chosen from the areas with different pollution levels: relatively clean, moderately polluted, hardly polluted. For the purposes of the comparison lichens were measured in Ilmen reserve, as the protected relatively clean territory. Using the method of lichen indication mapping we identified an indicator species Parmelia sulcate. Based upon epiphytic lichen distribution in sampling areas we distinguished several zones of atmospheric pollution: polluted zone, relatively clean zone, the cleanest zone. Lichen biodiversity and their projective cover are stated to decrease as the anthropogenic load is increasing. In urban and anthropogenic environment lichen population density is declining more intensively than the number of species. Also we measured elemental composition of lichens by X-ray fluorescence (XRF) analysis. We have studied the presence of heavy metals. Zink oxide, chrome and mangan oxide rate in the samples from environmentally troubled areas near steel factories and the power plantis almost twice higher.

  18. DEVELOPING A METHODOLOGY PACKAGE FOR LOCAL CAPITAL STOCKS MANAGEMENT : A CASE STUDY IN ICHIHARA CITY Download Article

    Tomomi Maekawa and Hidefumi Kurasaka
    • Article Type: Research Article
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    • Pages (107-114)
    • No of Download = 494

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    It is necessary that capital stocks be maintained in order to achieve environmental sustainability. However, there is as yet no firmly established methodology for maintaining and managing capital stocks. This study focuses on one example of a developmental process which took place in order to create a methodology package that will assist city officials and others such as the staff of not-for-profit organisations in Japan to manage local capital stocks. The methodology package has two main elements: providing access to a simulator which shows expected changes in local capital stocks in each city; and providing workshops to promote the sharing of knowledge and discussion among local students and people of other generations. Through the implementation of this methodology package by the project members, it has been found that these two elements generated a realisation within junior high school and high school students of expected changes to each city, and encouraged a diversity of ideas among them. Through promoting the sharing of ideas, this package has proved effective as a tool for generating suggestions regarding the management of capital stocks which have then been presented by participants at the workshops to the local mayor.

  19. ASSESSING TSUNAMI VULNERABILITY AREAS USING SATELLITE IMAGERY AND WEIGHTED CELL-BASED ANALYSIS Download Article

    Guntur, Abu Bakar Sambah, Fusanori Miura, Fuad, and Defrian Marza Arisandi
    • Article Type: Research Article
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    • Pages (115-122)
    • No of Download = 543

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    The application of multi-criteria analysis followed by weighted cell-based processing is one of the methods for tsunami vulnerability mapping. In this study, vulnerability due to tsunami disaster in coastal area of East Java Province Indonesia was carried out. Appropriate input criteria were derived from Digital Elevation Model data, satellite remote sensing and survey data. The criteria applied were elevation, slope, coastal proximity, river proximity, coastal type, and land use. Five classes of vulnerability were defined from low to high vulnerability. Digital Elevation Model from Aster GDEM was applied for creating elevation and slope map, while ALOS satellite image was used in land use mapping. Moreover, vector map of East Java coastal area was used for creating coastal type, coastal proximity, and river proximity map. Analytical hierarchy process was applied in the calculation of parameter’s weight, and it described that elevation was the highest weight. The area that identified as slightly high and high class of tsunami vulnerability spread in the coastal area which has a lower elevation and predict as inundated area. Most of the area was urban areas with low vegetation density. The high vulnerability areas were mostly found in the coastal area with the sloping coast type. The result presented here can aid as a basic data for city planning related to disaster mitigation and for the evacuation process and management strategy during disaster.

  20. VERTICAL HANDOVER DECISION MANAGEMENT ON THE BASIS OF SEVERAL CRITERIA FOR LVQNN WITH UBIQUITOUS WIRELESS NETWORKS Download Article

    Sunisa Kunarak and Raungrong Sulessathira
    • Article Type: Research Article
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    • Pages (123-129)
    • No of Download = 653

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    Vertical handover decision management is an essential to keep the seamless ubiquitous heterogeneous wireless networks since each access network has different operations in the next generation. In this paper, WCDMA, LTE and WLAN are cooperated in the architecture of mobile IP regional registration (MIP-RR). We propose the Learning Vector Quantization Neural Networks (LVQNNs) approach in order to maintain uninterrupted communication that depends on received signal strength indicator, data rate requirement, monetary cost of service and mobile terminal device speed metrics are considered as multi-criteria to initial handover. Furthermore, the multi-criteria are dynamic to influence for real-time and non-real time services in different networks and the users select the optimal target network which is the highest handover factor score in order to balance against the network condition and user preference. To ensure the Always Best Connected (ABC) demands, the simulation results illustrate that our proposed algorithm provided outperform the performance in term of unnecessary handover, the call dropping probability, data packet delay and network utilization compared with conventional method as fuzzy logic and neural network based machine learning.

  21. OBTAINING COMPLETE MIXING USING HYDRODYNAMIC ANALYSIS ON BATCH REACTOR Download Article

    Rositayanti Hadisoebroto, Suprihanto Notodarmojo, Idris Maxdoni Kamil, Yazid Bindar and Rangga Santosa
    • Article Type: Research Article
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    • Pages (130-134)
    • No of Download = 543

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    This research aims to find the best possible mixing conditions in a multi-phase reactor consist of wastewater, activated sludge and aeration. This has been done by analyzing flow profiles in the system using experimental and computational work. Hydrodynamic characteristics, such as influent flow rate, aerator configuration, baffle installment, play important role for wastewater treatment process. Determination of influent flow rate and the reactor configuration have done by analyzing flow profile in laboratory scale single-phase reactor with the dimension of 16 L. Velocity profile was developed from tracer study. There were 2 influent flow rate variations of 0,0095 L/s and 0,02 L/s, in 3 variations of reactor configuration. The first variation was without modification (control), the second was baffled reactor and the third was porous reactor. From the experimental work, it was obtained that the influent flow rate of 0,0095 L/s gave longer Residence Time Detention (RTD) and longer time to reach the outlet than flow rate of 0,02 L/s. The baffled configuration gave longer RTD and longer time to reach the outlet as well than other configuration. This two results was reasonable since the first influent flow rate and the baffled reactor have higher effective volume than other variations. In multi-phase system, experimental work was done in batch system to observe the contact between air-bubble and sludge in reactor, which then calibrated using CFD (Computational Fluid Dynamic) model. The result showed that the model of mixture in k- equation was considerable to use in future simulation work. The using of diffuser could increase mixing condition inside the reactor due to its higher effective volume.

  22. PREDICTION OF LOCAL SCOUR AROUND WIDE BRIDGE PIERS UNDER CLEAR-WATER CONDITIONS Download Article

    Nordila Ahmad, Thamer A. Mohammad and Zuliziana Suif
    • Article Type: Research Article
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    • Pages (135-139)
    • No of Download = 573

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    Local scour is the removal of sediment from around bridge piers due to flowing of water. A large amount of local scour is dangerous to the bridge piers and causes the structure tend to collapse and loss of life without any warning. Many researchers have already investigated the phenomenon of local scour around bridge piers. The literature search revealed that there is very little information on predictive equations or data on scour around wide piers. Most of the predictive equations in the literature are intended to apply equally well to large and small piers. Hence, this leads to a situation in which design is prioritised over prediction, which thus proves costly and economically inefficient. This study attempted to fill this gap where new experimental data from a physical model of scouring around a cylindrical and rectangular wide pier embedded in two types of uniform sediment beds are presented. The effects of sediment sizes and various pier widths on equilibrium scour depth of wide bridge piers are described. New empirical relation for the estimation of non-dimensional maximum scour depth for a wide pier were proposed as functions of the sediment coarseness. The experimental data obtained in this study and data available from the literature are used to validate the predictions of existing methods and the accuracy of the proposed method. The proposed method gives reasonable scour depth predictions and was verified with statistical methods where the root mean square error was reduced from 71% to 26%. The new empirical relation agrees satisfactorily with the experimental data.

  23. SUSPENDED SEDIMENT DYNAMICS CHANGES IN MEKONG RIVER BASIN: POSSIBLE IMPACTS OF DAMS AND CLIMATE CHANGE Download Article

    Zuliziana Suif, Chihiro Yoshimura, Oliver Saavedra, Nordila Ahmad and Sengheng Hul
    • Article Type: Research Article
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    • Pages (140-145)
    • No of Download = 486

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    This paper evaluates the potential impact of climate change and dams on suspended sediment (SS) dynamics in the Mekong River Basin (MRB). To this end, a distributed process-based sediment transport model was used to examine the potential impact of future climate and dams on suspended sediment dynamics changes in the MRB. Climate scenarios from two GCMs outputs together with effects of 3 existing, 5 under construction and 11 planned dams were considered in the scenario analysis. The simulation results show that the reductions in annual suspended sediment load (SSL) are likely to range from a 20 to 33%, 41 to 62%, and 71 to 81% for existing, under construction, and planned dams respectively in case of no climate change for baseline scenario (1991-2000). Moreover, the reductions on sediment concentration (SSC) are even greater (23% to 78%) due to the potential impact of dams. In contrast, the SSL and SSC shows 40% to 92% increase in the near future (2041-2050) and 28% to 90% in the far future (2090-2099). As the projected climate change impact of sediment varies remarkably between the different climate models, the uncertainty should be taken into account in sediment management. Overall, the changes in SSL and SSC can have a great implication for planned reservoirs and related sediment management.

  24. HEAVY METAL SPECIATION IN SEDIMENTS IN SAGULING LAKE WEST JAVA INDONESIA Download Article

    Eka Wardhani, Suprihanto Notodarmojo and Dwina Roosmini
    • Article Type: Research Article
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    • Pages (146-151)
    • No of Download = 630

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    The purpose of this study was to assess the chemical speciation of selected heavy metals (Cd, Cr, Cu, and Pb) in 12 surface sediments at Saguling Lake West Java Indonesia. A five-step sequential extraction technique was used to evaluate speciation heavy metals from Saguling Lake surface sediments. A risk assessment code (RAC) was applied to estimate the risk of heavy metals release in to the environment. The total mean value of heavy metals in surface sediment varied in the following descending order Cr>Cu>Cd>Pb. Based on the RAC value the sediments of Saguling Lake had been polluted by heavy metals, and they did pose medium ecological risk. The information on total metal concentrations in sediment was not sufficient for assessing the metal behavior in the environment, but metal speciation greatly determines the behaviors and toxicity of metals in the environment so it was more effective in estimating the environmental impact of contaminated sediments.

  25. ESTABLISHMENT OF JET INDEX Ji FOR SOIL ERODIBILITY COEFFICIENTS USING JET EROSION DEVICE (JEd) Download Article

    Saerahany L. Ibrahim, Jazuri Abdullah, Khairulafinawati Hashim and Junaidah Ariffin
    • Article Type: Research Article
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    • Pages (152-157)
    • No of Download = 611

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    Soil erodibility has been identified as one of the major factors that govern threshold of resistance to erosion. Accurate measurement of soil erodibility in the field is indeed important for the determination of critical shear stresses. Critical shear stress is the stress that initiates particle movement that promotes shifting of the bankline. An attempt to establish soil erodibility parameters was successfully carried out using a newly fabricated Jet Erosion Device (JEd) based on soil properties. Soil erodibility coefficients are introduced to represent the erodibility of the soils under study. Statistical test is used to confirm the validity and accuracy of the proposed technique. Field data measurements were carried out on 3 rivers. Empirical models were developed using data from Selangor River and validated using data from Bernam and Lui rivers and other secondary river data. Analyses have shown high correlations and the parameters were further examined and analysed for the development of a predictive relationship for Ji. The most accurate model was selected based on the adjusted R2, standard error of the estimate and discrepancy ratio to illustrate its significance. Selection of the predictive variables was based on their ability to explain the variation of Ji. The models established could significantly reduce the cost, time and usage of water supply for field data collection using JEd.