Aceh International Journal of Science and Technology
Not a member yet
294 research outputs found
Sort by
The Heat Exchanger Performance of Shell and Multi Tube Helical Coil as a Heater through the Utilization of a Diesel Machines Exhaust Gas
Get PDFA review on reutilization of heat waste from a diesel machine is absolutely important. This is because the exhaust gas potential of a Diesel machine keeps increasing and not much has been utilized by the industry. One of the techniques of reutilizing the heat waste in industry is by using a heat exchanger. The technique is also very useful for the environment because it can reduce air pollution caused by the exhaust gas of the diesel machine. The main purpose of the research is to find out the capability of shell and multi-tube helical coil HE as an air heater by utilizing the exhaust gas of the Diesel machine. The heat exchanger of shell and multi-tube helical coil utilizes the exhaust thermal gas of the Diesel machine as the air heater already made. The apparatus has the following dimension: the shell length of 1.05 m, diameter 0.1524 m, tube length of 3.25 m with 20 coils, tube diameter of 0.011 m, coil diameter of 0.0508 m with 4 helical coils. The type of Diesel machine to use in the testing is 4FB1 Isuzu Diesel engine. The machine has the maximum machine power and rotation of 54 kW and 3,600 rpm. The performance testing of heat exchanger has been conducted in some variations of Diesel machine rotations of 1,500 rpm, 1,750 rpm, 2,000 rpm, 2,250 rpm and 2,500 rpm. The testing result shows a maximum effectiveness to happen at the machine rotation of 1,500 rpm. The maximum effectiveness to get is 67.8% and then it goes down drastically in accordance with the increase of air mass flow rate. The hot air temperature created is from 47.1C to 52.3C so that it can be used for the purpose of drying up the unhulled rice
Using Landsat-8 Imagery Data on Mapping of The Seagrass Distribution in Matahari Island, Pulau Banyak District, Aceh Province, Indonesia
Get PDFThe objective of the present study was to gathers information about the seagrass distribution area using the remote sensing that retrieved from Landsat-8. Analysis of Landsat-8 image is classified into 6 classes; seagrass, coral reefs, sand, sea, and cloud. The agreement between processed image of seagrass bed and ground truth reference was 70%. The seagrass ecosystem is well distributed along the Matahari Island, with the total area approximately 44.0123 Ha
Modeling Hydrologic Response to Land Use and Climate Change in the Krueng Jreu Sub Watershed of Aceh Besar
Get PDFSoil and Water Assessment Tool (SWAT) model was used to simulate impact of landuse and climate change on water resources in Krueng Jreu subwatershed located in Aceh Province Indonesia. The subwatershed is a primary source of water to irrigated 233.52 km2 paddy field area through a surface irrigation system. The model performance was considerably good in predicting streamflow. The coefficients of determination varied between 0.58 and 0.72, while the Nash-Sutcliffe coefficients (ENS) ranged between 0.65-0.72 and the percentage bias were in the range of -0.36 to 2.30. Scenarios were applied to the best fit model to evaluate watershed responses to land use and climate changes. The model predicted increases in both runoff and water yield by 1% and 0.1% respectively as the result of increasing 15% settlement area. When all agricultural land within subwatershed converted to forest, water yield would increase by 1% during dry period and runoff contribution would decrease by 5%. Increases in surface flow by 23.6% and water yield by 15.1% were found under scenario of increasing 10% of daily precipitation. Increasing in evapotranspiration caused by an increase of 1.5C in daily air temperature would decrease surface flow and water yield by 0.8% and 1.3%, respectively. Combination scenarios of changes in daily temperature and precipitation would increase evapotranspiration rate, annual water yield and runoff contribution
Spatial Statistic Analysis of Earthquakes in Aceh Province Year 1921-2014: Cluster Seismicity
Get PDFThe purpose of this study is to apply the analysis of spatial patterns of earthquakes in the province of Aceh by detecting clusters and looking for spatial patterns locally and globally during the period 1921-2014 using GIS (Geographic Information System).The selected techniques are Average Nearest Neighbor, Moran Global Index, the Getis-Ord General G, Anselin Local Moran Index, the Getis-Ord Gi*, and Kernel Density Estimation.Each technique is implemented using GIS so that calculations can be done efficiently and quickly.The results of this study indicate that (1) The techniques can detect clusters of dots on the spatial pattern of earthquakes;(2) Both globally and locally, it shows that earthquakes clustered in the southwestern heading to the northern part of the province;(3) An earthquake with a greater magnitude generally concentrated in the district of Simeulue, the western part of Aceh Besar and northwest of Saban
Fate of Chemical Activators in The Aqueous Environment: What Should We Do About It?
Get PDFThe commonly used activators in chemical activation of activated carbon are very toxic and poisonous to the aquatic environment. Finding trade-off solutions without compromising the quality of activated carbon and jeopardizing the environment have become the subject of considerable interest. This paper is aimed to shed some light on the inevitable release of chemical activators to the aqueous environment, and offers some possible solutions to overcome the emergence of secondary pollution
The Design of a Portable Municipal Waste Incinerator With Fuzzy Logic Based Support for Emission Estimation
Get PDFA fuzzy logic interface system to estimate oxygen requirement for complete combustion as well as the level of pollution from incinerator gas flue in order to manage solid waste from domestic, institutional, medical and industrial sources was designed. The designed incinerator is double chambered operating with a maximum temperature of 760 C in the lower chamber and 1000C in the upper chamber. The insulating wall is made up of a refractory brick of 55mm in thickness having a 2mm thickness low carbon steel as the outer wall. Hydrogen Chloride (HCl) and Nitrous oxides (NO)x are the gases was used to demonstrate the Fuzzy Inference System (FIS) model. The FIS was built with five input variables (Food, PVC, Polythene, Paper and Textile) and three input variables with two membership functions. The FIS was developed to estimation the degree of possibility distribution of pollution that should be expected when a certain composition of waste is incinerated. The plots of composition of waste high in food against oxygen require for combustion gives a possibility distribution of about 0.9 which is high according to the fuzzy set definition while the plot of waste composition high in PVC against HCL shows linearity
The Spatial Distribution of Bed Sediment on Fluvial System: A Mini Review of the Aceh Meandering River
Get PDFDynamic interactions of hydrological and geomorphological processes in the fluvial system result in accumulated deposit on the bed because the capacity to carry sediment has been exceeded. The bed load of the Aceh fluvial system is primarily generated by mechanical weathering resulting in boulders, pebbles, and sand, which roll or bounce along the river bed forming temporary deposits as bars on the insides of meander bends, as a result of a loss of transport energy in the system. This dynamic controls the style and range of deposits in the Aceh River. This study focuses on the spatial distribution of bed-load transport of the Aceh River. Understanding the spatial distribution of deposits facilitates the reconstruction of the changes in controlling factors during accumulation of deposits. One of the methods can be done by sieve analysis of sediment, where the method illuminates the distribution of sediment changes associated with channel morphology under different flow regimes. Hence, the purpose of this mini review is to investigate how the sediment along the river meander spatially dispersed. The results demonstrate that channel deposits in the Aceh River are formed from four different type of materials: pebble deposited along upstream left bank; sand located on the upstream, downstream, and along meander belts; and silt and clay located along the cut bank of meander bends. Because of different depositional pattern, the distribution of the sediment along the river can be used as a surrogate to identify bank stability, as well as to predict critical geometry for meander bend initiatio
Stochastic Production Frontier Models to Explore Constraints on Household Travel Expenditures Considering Household Income Classes
Get PDFThis paper explores the variation of household travel expenditure frontiers (HTEFs) prior to CC reform in Jakarta. This study incorporates the variation of household income classes into the modeling of HTEFs and investigates the degree to which various determinants influence levels of HTEF. The HTEF is defined as an unseen maximum (capacity) amount of money that a certain income class is willing to dedicate to their travel. A stochastic production frontier is applied to model and explore upper bound household travel expenditure (HTE). Using a comprehensive household travel survey (HTS) in Jakarta in 2004, the observed HTE spending in a month is treated as an exogenous variable. The estimation results obtained using three proposed models, for low, medium and high income classes, show that HTEFs are significantly associated with life stage structure attributes, socio-demographics and life environment factors such as professional activity engagements, which is disclosed to be varied across income classes. Finding further reveals that considerable differences in average of HTEFs across models. This finding calls for the formulation of policies that consider the needs to be addressed for low and medium income groups in order to promote more equity policy thereby leading to more acceptable CC reform
PM3 and DFT Computational Studies of the Reaction Mechanism of Formaldehyde and Isoleucine
Get PDFThe reaction of formaldehyde and Isoleucine was studied using semi-empirical and density functional theory methods. Possible reactive sites are proposed and reaction mechanism postulated. It was found that the Isoleucine nitrogen attacks the carbonyl carbon of formaldehyde and forms a methylol intermediate that undergoes a condensation with another Isoleucine to produce a Methylenediisoleucine through a methylene bridge (cross-linking). The enthalpies of the reaction are -78.79 kJ/mol and -39.14kJ/mol for PM3 and DFT respectively also So and Go, for the PM3 and DFT studies predicted. The reaction was found to be exothermic and second order
Sorption Analysis of 137Cs On Karawangs Clay Samples
Get PDFThe objective of this work is to characterize the specific of distribution coefficient (Kd) values of 137Cs onto Karawangs clay for radioactive waste disposal facility purpose. Sorption phenomena was affected by contact time, ionic strength and loaded concentration of CsCl. Experiments were done in a batch method, with initial concentration was 10-8 M CsCl in the experiments of contact time and ionic strength effects. In the CsCl loading experiment, the concentration was varied from 10-8 to 10-4 M CsCl and 137Cs radioactive solution was used as a tracer. The solid-liquid ratio is 10-2 g/mL. The results shown that obtained Kd values were 21,714 and 4035 mL/g after contacted for 8 days for Sample-1 and 2, respectively. The presence of K+ and Na+ ions in solution had reduced the Kd value Cs-137 where the effect of K+ is greater than Na+ on decreased the value of Kd. The increasing of CsCl concentrations in solution had reduced the value of Kd. In both samples of clay were closely fit to Freundlich isotherm and pseudo-second order kinetic model. The results are very useful as the input of the safety assessment activity of site candidate for radioactive waste disposal facility in the future