Articles

  1. ADSORPTIVE BEHAVIOR OF LOW-COST MODIFIED NATURAL CLAY ADSORBENTS FOR ARSENATE REMOVAL FROM WATER Download Article

    Borano Te, Boonchai Wichitsathian and Chatpet Yossapol
    • Article Type: Research Article
    • View Abstract
    • Pages (1-7)
    • No of Download = 486

    Abstract

    close

    Millions of people in more than 70 countries are at risk of developing arsenicosis and other health issues due to consuming elevated arsenic contaminated water. The present study aimed to use natural clays heated at high temperature and treated with ferrous and ferric solutions through a simple coating technique enhanced by moderate temperature for arsenate uptake from water. BET, XRF, XRD and SEM methods were applied for the adsorbent characterization. Adsorption experiments were conducted in a series of batch systems in terms of contact time, solution pH, initial concentration and the presence of coexisting anions. The results indicated that the adsorption kinetics was better described by the pseudo-second order rate model for all adsorbents. All adsorbents exhibited higher arsenate uptake efficiency in the acidic condition. Langmuir model provided the maximum arsenate adsorption capacity of 250μg/g, 429.74μg/g and 747.38μg/g for calcined clay (MC), ferric calcined clay (MC-FeIII) and ferrous calcined clay (MC-FeII), respectively. Among added coexisting anions, phosphate (PO43-) significantly decreased the arsenate adsorption capacity of all adsorbents. Overall, regarded to a wide availability of raw materials, simplicity of the modification and improvement of arsenate adsorption capacity, modified natural clay adsorbents, especially MC-FeII, could be considered to be effective and low-cost to remove arsenate from water.

  2. NUMERICAL SIMULATION OF DESICCATION CRACKING PROCESS BY WEAK COUPLING OF DESICCATION AND FRACTURE Download Article

    Sayako Hirobe and Kenji Oguni
    • Article Type: Research Article
    • View Abstract
    • Pages (8-13)
    • No of Download = 622

    Abstract

    close

    The prediction of the possibilities for the desiccation cracking is important for the building construction because they could cause damages to the foundation structures. While the experimental and numerical researches were performed with various materials and conditions, the mechanism of the desiccation cracking is still not clear. In this research, the desiccation cracking is modeled by the coupling of the desiccation governed by the diffusion equation, the deformation, and the fracture. We perform the weak coupling analysis of the finite element analysis for the desiccation and the analysis of Particle Discretization Scheme Finite Element Method (PDS-FEM) for the deformation and the fracture. The simulation is carried out with the different thickness of the desiccation layer under various boundary conditions. The simulation results show the satisfactory agreement with the experimental observation in terms of the crack pattern with
    net-like structure, pattern formation process, and the change in size of the cells framed by the cracks depending on the thickness of the desiccation layer. This agreement between the simulation results and the experimental observations indicates that the coupling of desiccation, deformation, and fracture is a fundamental mechanism of the desiccation cracking.

  3. EVALUATION OF THE EFFECTIVENESS AND APPROPRIATENESS OF BANGKOK ACTION PLANS ON GLOBAL WARMING MITIGATIONS Download Article

    Anna Kiewchaum, Sarawut Thepanondh, Duanpen Sirithian, Kamolthip Mahavong and Pantitcha Outapa
    • Article Type: Research Article
    • View Abstract
    • Pages (14-21)
    • No of Download = 464

    Abstract

    close

    Bangkok Metropolitan Administration (BMA) action plans consist of 10 action plans aimed to reduce at least 15% of the total greenhouse gases emissions anticipated in the year 2012 under business as usual projection. In this study, the Multi Criteria Attribute (MCA) analysis was carried out to determine the most appropriate greenhouse gas mitigation measures for implementation in Bangkok, Thailand. Five criteria were used in this analysis included 1) mitigation potential, 2) total costs, 3) feasibility, 4) owner of benefits and 5) environmental benefits. Although, the action plan which focused on improving electricity consumption of the building and promoting electricity conservation campaign for Bangkok resident was expected to the highest reduction of greenhouse gases (2.7 million tons of CO2 reduction). However, effort on expanding of the park area was evaluated as the most appropriate initiative when consider both of its effectiveness in reducing emissions, and its implementation cost. Carbon removal rate of trees in Bangkok’s park was also evaluated through an intensive study at selected parks using data collected over the period of 10 years (2005-2015). It was found that the park in Bangkok could store carbon of about 1.86 tC/y (6.82 tCO2/y) or 0.58 tC/ha/y. These predicted results were coincided with actual outcomes evaluated from the implementation of each policy in the metropolitan area. Methodology of this study can be applied for further use in analysis and selection of appropriate measures for policy maker in other cities as well as in the national level.

  4. INVESTIGATING THE RELATIONSHIP BETWEEN RAINFALL INTENSITY, CATCHMENT VEGETATION AND DEBRIS MOBILITY Download Article

    Rick Jaeger and Terry Lucke
    • Article Type: Research Article
    • View Abstract
    • Pages (22-29)
    • No of Download = 537

    Abstract

    close

    Urbanisation creates the need for engineered hydraulic structures in catchments, floodplains and watercourses. These include piped and open-channel drainage networks, flood control systems and waterway crossings such as culverts and bridges. During larger storm events, debris and other material located higher in the catchment can be mobilised and transported towards these hydraulic structures creating the potential for blockages. This debris is often trapped by the hydraulic structures, causing partial or full blockage which can reduce the flow capacity of the structure. This may cause upstream flooding during high intensity rainfall events. This study investigated the debris transport behaviour in a natural channel. A model of an existing catchment and culvert system in Australia was build based on Froude similitude scaling. Different sized twigs were used to replicate natural debris of various sizes. The experimental results demonstrated that the mobility of debris during rainfall events was dependent on a range of factors including stream depth and width, the size and availability of debris, and on the condition of the riparian vegetation within the catchment. This could have significant implications for culvert design and maintenance procedures.

  5. ANALYTICAL SOLUTION FOR A LONG WAVES PROPAGATION IN TWO-LAYER FLUID OVER A SUBMERGED HUMP Download Article

    Fatimah Noor Harun and Muhammad Afiq Ahmad Khairuddin
    • Article Type: Research Article
    • View Abstract
    • Pages (30-37)
    • No of Download = 604

    Abstract

    close

    The study of internal waves has become important because they are associated with the energy transfer mechanism across continental shelf edges. In addition, they also can cause strong localized departures from the surrounding ocean conditions, resulting in increased shear stresses on underwater structures and large variations in acoustic transmission properties of the ocean. Therefore, the internal waves cause problems in many areas such as offshore oil recovery, acoustic propagation in the ocean, and deep water outfall. Hence, this paper is conducted to study the two-layer long-waves propagation through submerged humps using analytical solution. Equation involved in this study are mild slope equation and the methods involve are separation of variables and a series solution. In this study the effect of the geometry of the hump when water waves propagating through the humps are also studied. Besides, the density ratio also give significance effect to the surface wave elevation. An analytical solutions obtained in this study is useful in reviewing applications and condition of the wave amplitude on submerged hump.

  6. A COMPARISON OF PARALLEL BRANCH AND BOUND ALGORITHMS FOR LOCATION-TRANSPORTATION PROBLEMS IN HUMANITARIAN RELIEF Download Article

    Chansiri Singhtaun and Suriya Natsupakpong
    • Article Type: Research Article
    • View Abstract
    • Pages (38-44)
    • No of Download = 519

    Abstract

    close

    This paper studies the effect of branching rules (BR) and heuristic algorithms (HA) to find feasible solutions for a branch and bound (BB) algorithm used to solve sub-problems in a parallel two-phase branch and bound (PTBB) approach. The nine PTBB algorithms, which are developed by varying 32 combinations of BR and HA strategies, are tested on the facility location-transportation problem for disaster response (FLTDR). The mathematical model for the problem determines the number and location of distribution centres in a relief network, the amount of relief supplies to be stocked at each distribution centre and the vehicles to take the supplies in order to maximize the percentage of needs coverage of disaster victims under capacity restriction, transportation and budgetary constraints. To examine the performance of the algorithms, computational experiments are conducted on the various sizes of generated problems. Three strategies of BR and HA provided in the “intlinprog” function of MATLAB were applied for these problems. The objective function values and the computational times of all algorithms were collected and analyzed. The results showed that all PTBB algorithms can solve problem sizes of four candidate locations with fifteen demand points without premature termination by time. The PTBB algorithm using “maxfun” branching rules and “rss” heuristic to find a feasible solution is recommended for FLTDR because of the least computational time usage.

  7. GAS CONTENT APPRAISAL OF SHALLOW COAL SEAMS IN THE SOUTH PALEMBANG BASIN OF SOUTH SUMATRA Download Article

    Ana Asmina, Edy Sutriyono and Endang Wiwik Dyah Hastuti
    • Article Type: Research Article
    • View Abstract
    • Pages (45-52)
    • No of Download = 725

    Abstract

    close

    The gas content of coal seams in the South Palembang basin has been assessed using well log data and core analysis. The seams are stratigraphically exposed at shallow levels (<300 m), and present in the Late Miocene-Early Pliocene Muara Enim sequence. The coal thickness of single bed in each well varies between ~7 m and ~14 m. All samples analyzed are low rank coals, suggesting subbituminous and high volatile bituminous. Vitrinite reflectance (VR) measurements vary from 0.49-0.59%, but there appears an increase in the VR value with depth. The coals contain predominantly huminite (56-86 vol. %), whereas liptinite and inertinite are less abundant, ranging from 0.2-12.2 vol. % and 4.2-19.2 vol. % respectively. These low rank coals comprise a small number of minerals (6-11 vol. %), high moisture content of 2.4-12.6 wt. %, volatile matters of >39 wt. %, and fixed carbons of >43 wt. %. The amount of gas within individual coal layer varies from 4.1-5.3 m3/t, but the gas content tends to increase with deeper burial. The sum of the estimated gas-in-place is approximately 3,019x106 m3. In addition, the onset of gas generation within these near surface coals may occur due to biogenic controls during the coal-forming processes, as a result of sedimentation of the overburden in Pliocene time prior to the subsequent basin inversion commencing in the Plio-Pleistocene.

  8. FLOW CONTROL THROUGH VORTEX SHEDDING INTERACTION OF ONE CYLINDER DOWNSTREAM OF ANOTHER Download Article

    Jonathan Payton and Sam M Dakka
    • Article Type: Research Article
    • View Abstract
    • Pages (53-59)
    • No of Download = 536

    Abstract

    close

    This study investigates the vortices produced between two 2d cylinders, and the relationship between the structures of the vortices produced at both cylinders when one is placed in the wake flow of another. CFD simulations using ANSYS Fluent were used to determine the coefficients of lift and drag, as well as the frequency of vortex shedding and size of vortices at three separate Reynolds numbers of 16000, 32000 and 65000 in different arrangements. Each arrangement of cylinders was compared against controls, which consisted of a single cylinder to determine the alteration of forces produced. Two trip wires at 7 different angles of 40, 45, 50, 55, 60, 65, and 70 degrees were then investigated at a Reynolds number of 65000 which was compared to the smooth cylinder control forces and frequency of vortex shedding. The most optimum angle of trip wires was then combined with linear cylinder arrangements also at a Reynolds number of 65000 for comparison with only the upstream cylinder utilizing the trip wires.

  9. FEASIBILITY STUDY OF BIODIESEL PRODUCTION FROM RESIDUAL OIL OF PALM OIL MILL EFFLUENT Download Article

    Monthatip Klabsong, Nipapun Kungskulniti, Chanakan Puemchalad, Naowarut Charoenca and Vittaya Punsuvon
    • Article Type: Research Article
    • View Abstract
    • Pages (60-64)
    • No of Download = 539

    Abstract

    close

    Pollution from residual oil contaminating wastewater is a serious environmental problem. The rapid development and growth of palm oil industries in Thailand have generated large volumes of palm oil mill effluent (POME) which contains residual oil. Instead of becoming a pollutant in the environment, residual oil from POME can be used as raw material for producing biodiesel. Biodiesel has recently become more attractive as an alternative energy source due to its environmental friendly properties generated from renewable resources. This study investigated the characteristics of residual oil and found: a free fatty acid content of 22.03 % wt, fatty acid methyl ester (FAME) of 3.767 %wt, acid value of 49.29 mg KOH/g, water content of 1.01 % mg/Kg, and total glycerines as monoglycerides, diglycerides, and triglyceride at 1.15 % m/m, 11.88 % m/m, and 87.54 % m/m respectively. Optimal conditions to separate water from oil contents are also determined. Separation of residual oil from POME is carried out using the solvent extraction process.

  10. ANALYSIS OF TIME-DEPENDENT MERCURY FLOWS THROUGH THE USE OF THERMOMETERS AND SPHYGMOMANOMETERS IN THAILAND Download Article

    Manaporn Wongsoonthornchai, Ruth Scheidegger, Suphaphat Kwonpongsagoon and Hans-Peter Bader
    • Article Type: Research Article
    • View Abstract
    • Pages (65-70)
    • No of Download = 436

    Abstract

    close

    Thermometers and sphygmomanometers pose a potentially large source of mercury emissions to the environment due to their high elemental mercury content. Many countries, e.g. most European countries, US have banned their uses already and many more strictly limited their use. However, in Thailand these mercury-based devices are still used, accumulating large stocks in the use phase as well as in landfills. To understand the development of mercury stocks and flows from thermometers and sphygmomanometers, a time-dependent mathematical material flow model is used in this study. The flows of mercury through these two products were calculated based on data between the years of 1962 and 2013. The simulation showed that the stock of mercury in thermometers is about 20 times smaller than the stock in sphygmomanometers. However the sum of waste flows and emissions to air and water from thermometers is 3 times larger than from sphygmomanometers. The reason is the lifetime of thermometers which is about 70 times shorter than the lifetime of sphygmomanometers. The calculated emission to air from mercury thermometers in hospitals can explain the higher mercury level measured in urine of health care staff. In order to reduce the mercury flows to the environment mercury thermometers should be replaced by alternative products as soon as possible.

  11. MERCURY CONTAMINATION IN ENVIRONMENT SURROUNDING COAL-FIRED POWER PLANT Download Article

    Kamolthip Mahavong, Poranee Pataranawat and Sopa Chinwetkitvanich
    • Article Type: Research Article
    • View Abstract
    • Pages (71-77)
    • No of Download = 547

    Abstract

    close

    Fossil fuels combustion has been widely known of their emission containing various heavy metals and gaseous substances. This study is to investigate the distribution of mercury (Hg) in environmental media surrounding the lignite coal-fired power plant in Lampang province, Thailand. Samples of surface soil and waters were collected within the vicinity of the power plant in order to analyze mercury contamination. Also, Hazard Quotient (HQ) will be determined to estimate environmental potential risks in this area of concern. Mercury contents in surface soil samples were observed in the range of 65 – 1338 μg/kg. The results also revealed that the distribution of mercury contamination in surface soils partly correlate with monsoon domination or distance from the power plant. Some samples of surface water and ground water in this area contained mercury concentration in the range of 0.1 μg/l – 0.2 μg/l. These mercury contents were further considered for environmental potential risks by HQ calculation. The environmental potential risks of mercury content in surface soil samples and water samples were classified as no environmental hazard (HQ < 1).

  12. THE ANAEROBIC BAFFLED REACTOR (ABR): PERFORMANCE AND MICROBIAL POPULATION AT VARIOUS COD LOADING RATES Download Article

    Sopa Chinwetkitvanich and Apaporn Ruchiraset
    • Article Type: Research Article
    • View Abstract
    • Pages (78-84)
    • No of Download = 479

    Abstract

    close

    Anaerobic Baffled Reactor (ABR) is one type of high-rate anaerobic reactor equipped with a series of baffles. This baffles plays an important role of biomass retaining, consequently, sludge retention time (SRT) could be operated separately from hydraulic retention time (HRT) without needs of filter or media packing. Three 10-liter laboratory scale ABRs with different compartment numbers (3, 6 and 8 compartments) were operated with constant HRT of 24 hrs. Synthetic carbohydrate-protein wastewater was fed to these reactors with COD loading rate of 4 g COD/l-d. The results evidently showed that the compartmentalized structure of ABR helped retard sludge washout rate. The more compartments, the lower of sludge washout rate was. The ratios of SRT/HRT were found as 35, 73 and 134 d/d in the reactors with three, six and eight compartments, respectively. In addition, COD removal efficiencies were observed with percentages of 74, 78 and 83, respectively. Moreover, studying of the microbial populations by FISH technique proved the existence of microbial phase (methanogens and acidogens) separation in ABR system with six and eight compartments, but not clearly distinguishable in three-compartment ABR.

  13. DEEP BASEMENT EXCAVATION IN SOFT BANGKOK CLAY CLOSED TO PALACES Download Article

    Wanchai Teparaksa
    • Article Type: Research Article
    • View Abstract
    • Pages (85-90)
    • No of Download = 838

    Abstract

    close

    The Bank of Thailand (BOT) head office is a large building constructed in the inner Ratanakosin Island of Bangkok along Chao Phraya River, a main river of Bangkok, where high-rise building construction with more than three stories is not permitted. The BOT building consists of five basements with excavation depth of 15.8 meters and only three stories of super structure. The soil condition consists of 15 m. thick soft to medium clay followed by stiff silty clay and sand layer. The basement construction was constructed only five meters away from Tewavej Palace and ten meters away from Bangkhunphrom Palace. The damage assessment by means of Finite Element Method (FEM) with simulation of basement construction method was carried out to predict the influence on both palaces. Finally, the top-down construction method was selected for basement construction with one meter thick and 20 meters long of diaphragm wall which was designed together with the 50 meters long bored pile to support the whole building. The full set of instrumentation was installed at the palaces, diaphragm wall and ground surface for monitoring the field performances and effect to the palaces during and after basement construction. The field measurement and FEM prediction is compared and the time dependent of lateral wall movement is discussed. The construction was completed without any damage or effect to both palace.

  14. EFFECT OF TEMPERATURE ON REMOVAL OF COD AND TSS FROM ARTIFICIAL RIVER WATER BY MUDBALLS MADE FROM EM4, RICE BRAN AND CLAY Download Article

    Fadjari Lucia Nugroho, Deni Rusmaya, Yonik Meilawati Yustiani, Fajar Ibnil Hafiz and Runie Besty TetaPutri
    • Article Type: Research Article
    • View Abstract
    • Pages (91-95)
    • No of Download = 598

    Abstract

    close

    In Indonesia surface water is often polluted by domestic waste causing degradation of river water quality. The use of activated Effective Microorganism Solution (EMS) mixed with rice bran or wheat bran, as well as soil and shaped into mudballs has in recent years shown promise as a direct method to improve quality of polluted river water. This study examined the effect of temperature on removal of COD and TSS by mudballs made from activated EM4 solution, rice bran and clay soil. Batch experiments treating artificial river water by the mudballs were conducted at temperatures 25ºC and 30ºC with the artificial river water having initial levels of 120 mg/L COD and 100 mg/L TSS. Efficiency removals of COD by 2.5 cm  mudballs at 25ºC and 30C were 66.7% and 59.4%, whereas that of TSS were 100% and 99.7% respectively. TSS sorption by the mudballs appears to better fit the Langmuir than the Freundlich isotherm models. At 25ºC and 30C, maximum sorption (Qm) of TSS is 6.89 mg/g and 7.52 mg/g; Langmuir constant (KL) is 0.0196 L/mg and 0.0168 L/mg, while equilibrium parameter (RL) is 0.338 and 0.373 respectively. Statistical hypothesis testing of the experimental data suggests that at =0.05, temperature affects removal efficiency of COD but not that of TSS.

  15. EVALUATION OF RESUSPENSION OF ROAD DUST IN A CEMENT INDUSTIAL COMPLEX ARE Download Article

    Tipawan Phetrawech and Sarawut Thepanondh
    • Article Type: Research Article
    • View Abstract
    • Pages (96-103)
    • No of Download = 430

    Abstract

    close

    Re-suspended road dust is an important contributor to ambient particulate matter (PM) particularly in an area where fugitive dust is significant emission source. This study evaluate PM-10 and PM-2.5 emissions as fugitive re-suspended dust from the road network in the Thai’s Pollution Control Zone. Emissions of road dust are determined by using the analysis of silt loading and physical characteristics of the roads located in the study domain. Diurnal profile of vehicles travelling on each roads were used to calculate temporal variation of the emission data. Diurnal pattern of PM-10 ambient concentration measured from curbside station in the study area was used to reveal the contribution of road dust emissions to particulate concentration in the air. Results indicated that road dust greatly influenced the temporal profile of PM-10 concentrations in this area. Therefore, the effort to control particulate emissions in this Pollution Control Zone should also give a priority not just only to the industrial sources but also to mobile source emissions particularly from those re-suspended road dust.

  16. A NEW QUEUING TECHNIQUE IN ADAPTIVE MULTIPATH ROUTING FOR CONGESTION CONTROL WITH PACKET PRIORITY IN WIRED DATA NETWORKS Download Article

    N.Krishna Chaitanya and S.Varadarajan
    • Article Type: Research Article
    • View Abstract
    • Pages (104-108)
    • No of Download = 569

    Abstract

    close

    This paper proposes a new queuing technique in Adaptive Multi-Path routing based on packet priority. Simultaneous Multi-Path routing is used to improve the data performance over a congested network. The traditional method of transmitting the data is done by using Simultaneous Multi Path Communication (SMPC). Two types of SMPCs are proposed, in which SMPC-I, which uses multiple paths independently and SMPC-P, which uses path priority control algorithm in conjunction with SMPC. SMPC-I and SMPC-P maintains throughput regardless of path length and priority control. In addition to available SMPC methods, proposed method provides better solution to improve the performance of communication network. A theoretical approach of AMPC-PP proposed here based on packet priority for important data over normal data on a congestion network with route adaptability.

  17. ROLE OF PUBLIC PARTICIPAITON IN ENVIRONMENTAL IMPACT ASSESSENT IN THAILAND Download Article

    Chutarat Chompunth
    • Article Type: Research Article
    • View Abstract
    • Pages (109-113)
    • No of Download = 686

    Abstract

    close

    An integration of public participation in Environmental Impact Assessment (EIA) is significant in terms of its implication for sound decision and a sustainability of development projects. Accordingly, the Thai EIA system provides a public participation process for stakeholders in an assessment and review of the EIA study process. There are a number of different participatory techniques to facilitate public participation. However, in Thailand traditional public participation methods like public hearing is preferred. The public hearing process in the Thai context, stakeholders including the project proponents and the opponents are brought together in a forum to express their view points and recommendations for the proposed projects in order to influence the decision-making process. Frequently, this process leads to violent conflict among stakeholders. This study aimed at trying to close the gap between regulators and civil communities with respect to public participation in the Thai EIA system. A case study approach was applied for this study. The study revealed that appropriate public participation is essential and may lead to enormous benefits for the proponents and stakeholders. Where public participation is ignored and ineffective conducted, environmental conflicts and problems may be created for project implementation and sustainability.

  18. ASSESSING TEMPORAL MOMENT CHARACTERISTICS OF SOLUTE TRANSPORT PHENOMENA IN HETEROGENEOUS AQUIFERS USING RANDOM WALK PARTICLE TRACKING Download Article

    Yasuteru Kobi, Kazuya Inoue and Tsutomu Tanaka
    • Article Type: Research Article
    • View Abstract
    • Pages (114-121)
    • No of Download = 567

    Abstract

    close

    Solute transport phenomenon is one of the crucial issues in predicting and spreading of a contaminant plume in natural aquifers. In this study, conservative solute transport simulations were conducted in two-dimensional heterogeneous aquifers to assess the transitional development of temporal moment characteristics up to the fourth order associated with macrodispersion phenomena. The aquifer system investigated here relied on the hydrogeologic data in the southwest of the Netherlands and was modeled as the heterogeneous aquifer with a certain geometric variance. Three types of physical heterogeneities in subsurface materials were represented as randomly correlated hydraulic conductivity fields, which were geostatistically generated under the isotropic assumption of the correlation length. Random walk particle tracking linked with temporal moment approach, which was based on observed breakthrough curves at several predefined control planes, demonstrated asymptotic variations of the second and fourth moments. Results also showed that the degree of the physical heterogeneity affected the degree of the increase of each moment, indicating that this plume behavior reflected the hydraulic conductivity distribution on which the evolution of plume was considerably dependent.

  19. TREATMENT EFFICIENCY AND COMPRESSIBILITY BEHAVIOR OF SOIL MODIFIED WITH POWDERED ACTIVATED CARBON Download Article

    Mohd Yuhyi Mohd Tadza and Fauzi Baharudin
    • Article Type: Research Article
    • View Abstract
    • Pages (122-126)
    • No of Download = 622

    Abstract

    close

    Riverbank filtration (RBF) systems are often used to treat surface water near rivers. The effectiveness of such systems depends heavily on the properties of the riverbank material that is used for filtering and treating the water. To improve the system’s treatment efficiency, modifications may be conducted to the riverbank soil. Altering the properties of the soil might, however, affect the stability of the riverbank. In this study, soil and water samples near Lake Chini were collected and characterized. Filtration test was conducted to evaluate the efficiency of the soil in treating the water. The soil was modified by mixing it with powdered activated carbon (PAC) at varying percentage of 5 and 10%. In addition, compressibility test was carried out using a standard oedometer. Test results indicated that the soil alone was insufficient to treat the water to drinking water quality standards. Modification with activated carbon improved the water quality from Class II to Class I. However, compressibility test revealed that there were some changes to the pressure - void ratio relationship, indicating that the alteration of soil properties with the addition of activated carbon filters might affect the stability of the riverbank.

  20. SHEAR STRENGTH OF CLAY REINFORCED WITH SQUARE AND TRIANGULAR ARRANGEMENT OF GROUP ENCAPSULATED BOTTOM ASH COLUMNS Download Article

    Muzamir Hasan, Nurul Aina Husaini and Norhayani Pangee
    • Article Type: Research Article
    • View Abstract
    • Pages (127-133)
    • No of Download = 525

    Abstract

    close

    Soft clay is known to be a problematic soil that consists of low shear strength, low permeability and high compressibility where the existing soil on the given site is low with load bearing capacity, and by that ground improvement is required. Granular column methods are being used extensively as ground improvement technique for supporting a wide variety of structures and infrastructures. In practice, the bearing capacity on soft clay increased by a layer of compacted sand or gravel. Bottom ash as by product of coal burning that has similar properties to granular material can be applied as one of the stabilizing method to the existing soil. Hence, by using bottom ash as substitute, the cost of construction can be reduced and make great progress of a growing awareness of the sustainable engineering. This research discusses the results of the improvement in the shear strength of soft clay after being reinforced with a group of square and triangular encapsulated bottom ash columns. The physical and mechanical properties of the materials used such as kaolin and bottom ash were determined. The results show that kaolin can be classified ad clayey soil and bottom ash has similarities of characteristic with granular material. A total of 52 unconfined compression tests had been conducted on kaolin specimens to determine the shear strength. The diameter for specimen is 50 mm and 100 mm in height. The diameter of bottom ash columns are 10 mm and 16 mm respectively and the height of the column are 60 mm, 80 mm and 100 mm. The group columns have been arranged in square and triangular pattern. It can be concluded that the shear strength parameters were improved based on the different diameter and the height of the column.

  21. INFLUENCE OF RAILINGS STIFFNESS ON WHEEL LOAD DISTRIBUTION IN ONE- AND TWO-LANE CONCRETE SLAB BRIDGES Download Article

    Mohammad Abou Nouh, Ghassan Fawaz, Mounir Mabsout and Kassim Tarhin
    • Article Type: Research Article
    • View Abstract
    • Pages (134-138)
    • No of Download = 465

    Abstract

    close

    The American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (AASHTO LRFD) do not account for the presence of railings as integral parts of highway bridges. This paper presents the parametric investigation of the influence of railings stiffness on the wheel load distribution in simply-supported, one-span, one- and two-lane reinforced concrete slab bridges using the finite-element analysis (FEA). A total of 80 bridge cases are modeled and bridge parameters such as span lengths and slab widths were varied within practical ranges. Various railings built integrally with the bridge deck are placed on both edges of the concrete slabs. The FEA wheel load distribution and bending moments are compared with reference bridge slabs without railings as well as to the AASHTO design procedures. According to the FEA results, the presence of railings reduces the longitudinal bending moment in slabs by 25% to 60% depending on the stiffness of the railings. The results of this investigation will assist structural and bridge engineers in better designing or evaluating concrete slab bridges in the presence of railings. This can also be considered to be a possible alternative for strengthening existing concrete slab bridges.

  22. RESOURCE USAGE PREDICTION BASED ON ARIMA-ARCH MODEL FOR VIRTUALIZED SERVER SYSTEM Download Article

    Biju R Mohan and G Ram Mohana Reddy
    • Article Type: Research Article
    • View Abstract
    • Pages (139-146)
    • No of Download = 444

    Abstract

    close

    Performance degradation is unavoidable in server systems and this is because of factors such as shrinkage of system resources, data corruption, and numerical error accumulation. The resource shrinkage leads to the system failure due to the error propagation. Thus the resource prediction is useful to the administrator of the system so that an accidental outage can be avoided. It has been observed in past that most of the failures occur due to the exhaustion of free physical memory, so here free physical memory of a server consolidation setup is observed. It is also found that most of the studies in this direction were using the measurement-based approach with time series models for prediction. This paper reviews the effectiveness of such models and it examines whether volatility is present in the data or not. It checks whether Gauss-Markov assumptions about homoscedasticity holds good for the ordinary least square estimators of such models or not. This paper applies a combination of AutoRegressive Integrated Moving Average - AutoRegressive Conditional Heteroskedastic (ARIMA-ARCH) model to predict resource usage. Experimental results demonstrate that the goodness of fit of the ARIMA-ARCH Model has improved when compared to the linear ARIMA model.

  23. HE VALUE OF GREEN BELTS IN URBAN SPRAWL: A CASE STUDY OD TAICHUNG CITY, TAIWAN Download Article

    Chih-Hao Chen and Walter Den
    • Article Type: Research Article
    • View Abstract
    • Pages (147-152)
    • No of Download = 509

    Abstract

    close

    The role of green belts is not only to provide the recreation for human activities but also to improve environmental quality and to provide refuges for wildlife under intensified urban development. After the new demarcation of administrative areas, the influx and construction of industrial zones and commercial buildings has caused a major change of the original landscape in the Dadu hill area in Taichung City, Taiwan. The aims of this study are to provide recommendations pertaining the design of ecological corridors to improve the connectivity of the remaining green places, and the assessment of the health of habitat for the developed urban area. We compared the biodiversity (birds, mammals, plantation) and carbon flux in three different suburban areas including a campus, a metropolitan park and an undeveloped woodland in regular disturbance by human and fire. According to the results of habitat similarity, the metropolitan park and campus were grouped with the higher diversity of birds, but the woodland had the higher diversity of plantation and mammals. Seasonal change is the main factor which affects the carbon flux and vegetation growth situation, and the disturbance by human activities and canopy and coverage by plantation are the causes of fluctuations. The habitat assessment which integrated the biodiversity and carbon flux provided another angle to evaluate the greenbelt design comprehensively. However, the quantification of the whole ecosystem service value is a further direction of environment management, especially in green place conserving under the urban sprawl.

  24. FFECTIVENESS OF USING RIVER INSECT LARVAE AS AN INDEX OF CU, ZN AND AS CONTAMINATIONS IN RIVERS, JAPAN Download Article

    Hiroyuki Ii and Akio Nishida
    • Article Type: Research Article
    • View Abstract
    • Pages (153-159)
    • No of Download = 623

    Abstract

    close

    Analysis of Dobsonfly (a kind of Megaloptera, Protohermes grandis) larvae for concentrations of Cu and Zn was found to be an effective method of determining levels of Cu and Zn contamination of rivers in metal mine areas and non-metal mine catchments. Metal concentration in Dobsonfly larvae was used as an index of metal contamination because the amount of metal concentration in Dobsonfly larvae decreased with the dry weight of the larvae and also on the degree of metal present in the river water. Dobsonfly makes an excellent tool for contamination evaluation because of their easy classification, wide distribution and commonness. Furthermore, due to their relatively lengthy 2-3 year lifespan, river contamination assessment over a long term could be performed. In this study, Cu, Zn and As concentrations in river insect larvae in metal mine areas were found to be higher than those in non-mine catchments.

  25. MICROCOSM EXPERIMENTS ON A COCONUT-FIBRE BIOFILM TREATMENT SYSTEM TO EVALUATE WASTE WATER TREATMENT EFFICIENCIES Download Article

    Naofumi Sato, W. N. K. Dharmarathne, Takeshi Saito, Hiroyasu Sato, Norio Tanaka and Ken Kawamoto
    • Article Type: Research Article
    • View Abstract
    • Pages (160-166)
    • No of Download = 405

    Abstract

    close

    Interest in utilization of locally available biomasses as biofilm support media for wastewater treatment in developing countries is increasing. In this study, microcosm experiments on a coconut-fibre biofilm treatment system were carried out to evaluate wastewater treatment efficiencies in the laboratory using two wastewaters, synthetic sewage and leachate, with different pollutant loads. Three coconut-fibre conditions were set as a single bundle (low fibre density: LFD), two bundles (high fibre density: HFD), and no coconut fibre (blank). The wastewater was first circulated in the system for six weeks (circulation stage) and then discharged from the treatment tank for 7–24 weeks (treatment stage). Water quality parameters of effluents, pH, DO, EC, BOD, COD, TC, and TN, were measured at one-week intervals, and the sedimented sludge in each treatment tank was collected to determine C, N, and P contents. Results showed effective reductions in BOD and COD in the LFD and HFD conditions for the synthetic leachate, indicating that the coconut fibre contributed to the treatment of wastewater. On the other hand, the fibre density had less or no effect on the reduction of water quality parameters in the synthetic sewage. For both synthetic sewage and leachate, the C and N consumptions generally increased in the order of blank, LFD, and HFD. In particular, sludge sedimentation contributed to C consumption under the HFD condition.

  26. 1-D COMPRESSIBILITY PARAMETERS OF LIGHTLY SOLIDIFIED DREDGED MARINE SOIL (DMS) USING CEMENT, GGBS AND COARSE SAND Download Article

    Suaathi Kalianan and Chee-Ming Ch
    • Article Type: Research Article
    • View Abstract
    • Pages (167-171)
    • No of Download = 515

    Abstract

    close

    A consistent dredging is essential for the development along the coast and the maintenance of shipping routes. The dredging operation dislodges sediments from the seabed, and the retrieved materials, termed dredged marine soils, are considered a geowaste for dumping. Therefore reusing the material will benefit the civil sectors, and one option is solidifying with other materials, which are, cement, ground granulated blast furnace slag (GGBS) and sand. The present investigation is on a dredged marine soil (DMS) from Kuala Perlis state in Malaysia where in a laboratory study was undertaken to contemplate the compressibility characteristics of DMS with cement, GGBS and sand admixtures. Cement is the major constituent of concrete which is produced by natural raw materials like limestone rock, clay and chalk etc. These are produced by blasting quarries. Industrial wastes like Ground Granulated Blast Furnace Slag (GGBS) show chemical properties similar to cement. An attempt was made to understand the influence of cement plus GGBS as binder and sand as a granular material by studying the improved settlement rate of consolidation. The results showed that the optimum binder content was from 3C7G_20 specimen and when sand was added to it, it present that settlement decreased with increasing sand content. Binder combinations involving ratio of cement to GGBS of 3 to 7 with addition of sand were effective in improving the settlement and consolidation rate when compared to the performance of cement alone as binder.