Aceh International Journal of Science and Technology
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The Hardness of Boride Layer on the S45C Iron (A preliminary study on surface hardening of ferrous material)
Get PDFAbstract - The property such as microhardness of boridelayer formed on S45C iron was investigated. Boronizing was carried out in a solid medium consisting of nano size powders of 50% B4C as a donor, 45% SiC as a diluent, and 5% KBF4 as an activator treated at the temperature of 10000C for 8 hours. The phases that were formed on the substrate was found as Fe2B and FeB layer that had smooth and flate shape morphology. The hardness of boride layer on S45C was over 2000 HV, while the hardness of untreated S45C iron was about 196,39 HV. Depending on process time and temperature, the depth of boride layer ranges from 25 to 55 m, leading to a diffusion controlled process.Keywords : Boronization, hard layer, heat treatment, B4C.KBF4.SiC powder, low carbon steel
A Preliminary Study on Rainfall Interception Loss and Water Yield Analysis on Arabica Coffee Plants in Central Aceh Regency, Indonesia
Get PDFAbstract - Rainfall interception loss from plants or trees can reduce a net rainfall as source of water yield. The amount of rainfall interception loss depends on kinds of plants and hydro-meteorological characteristics. Therefore, it is important to study rainfall interception loss such as from Arabica Coffee plantation which is as main agricultural commodity for Central Aceh Regency. In this study, rainfall interception loss from Arabica Coffee plants was studied in Kebet Village of Central Aceh Regency, Indonesia from January 20 to March 9, 2011. Arabica coffee plants used in this study was 15 years old, height of 1.5 m and canopy of 4.567 m2. Rainfall interception loss was determined based on water balance approach of daily rainfall, throughfall, and stemflow data. Empirical regression equation between rainfall interception loss and rainfall were adopted as a model to estimate rainfall interception loss from Arabica Coffee plantation, which the coefficient of correlation, r is 0.98. In water yield analysis, this formula was applied and founded that Arabica Coffee plants intercept 76% of annual rainfall or it leaved over annual net rainfall 24% of annual rainfall. Using this net rainfall, water yield produced from Paya Bener River which is the catchment area covered by Arabica Coffee plantation was analyzed in a planning of water supply project for water needs domestic of 3 sub-districts in Central Aceh Regency. Based on increasing population until year of 2025, the results showed that the water yield will be not enough from year of 2015. However, if the catchment area is covered by forest, the water yield is still enough until year of 202
Potential Biomass Evaluation on Forest Plant Stands In Aceh Province, Indonesia: A Case Study of Forest Product Utilization Permit for Cultivated Forest Area by PT. Acehnusa Indrapuri
Get PDFAbstract Development of industrial forest plantation currently has a primary function to produce timber for the fulfillment of the pulp and paper industry raw matter. In times of growing trees plantations have the ability to absorb carbon dioxide gases (CO2) in the atmosphere throught the process of photosynthesis which builds biomass stands and produce oxygen gases (O2). The potency of forest stands biomass and build a model standing stock biomass using the Normalized Difference Vegetation Index (NDVI) value from Satellite Imagery was investigated. Types of crops grown in Forest Product Utilization Permit for Cultivated Forest Area in PT.Acehnusa Indrapuri are A.mangium and E.urophylla plantations with area approximately 15,500.59 ha. The results showed the biomass content at the lowest value 16.81 tons per hectare with the NDVI Value of 0.342 whereas the highest content of biomass amounted to 145.750 tons per hectare in NDVI value 0.813. The content of plant biomass of forest stands can be expected by NDVI values using the model equation Y = 250.32 X 2 -15.221X- 3.3623 with R2 of 97.27
Grey Model for Stream Flow Prediction
Get PDFAbstract Design, operation and planning of water resources, irrigation and water supply systems require estimation of stream flow. A grey system or stochastic approach is required for dealing with the hydrological complexities of mid and long-term stream flow prediction. Generally relatively long period data series of stream flow records is required for the prediction using stochastic methods. In developing countries like India, availability of long period hydrological records is a problem. Grey system theory is applicable in the case of unclear inner relationship, uncertain mechanisms and insufficient information and requires only small samples for parameter estimation. Stream flow records of Bharathapuzha river basin, Kerala, India is subjected to grey analysis. Model parameters were estimated using leastsquares method. Statistical indices for the developed models indicate their ability to predict stream flow in the river under study with reasonable accuracy
Linear Subspaces of Solutions Applied to Hirota Bilinear Equations
Get PDFAbstract - Linear subspace of solution is applied to Boussinesq and Kadomtseve-Petviashvili (KP) equations using Hirota bilinear transformation. A sufficient and necessary condition for the existence of linear subspaces of exponential travelling wave solutions to Hirota bilinear equations is applied to show that multivariate polynomials whose zeros form a vector space can generate the desire Hirota bilinear equations with given linear subspaces of solutions and formulate such multivariate polynomials by using multivariate polynomials which have one and only one zero.Keywords: Hirota bilinear form, solton solution, N-wave solution, linear subspaces
A Review on Viscometer Devices for Gas Phase
Get PDFAbstract -Viscosity, one of the transport properties, is a basic property required for developing anydevice in which fluid flows. In the present paper, major gas viscometers devices are reviewed. Thereview is covering to the pressures and the temperatures ranges, methods and accuracy of theinstruments, and the coefficient of viscosity-range of the sample. This study is expected becomeuseful information for any researcher who wants to develop a gas viscometer apparatus in a nearfuture. By identifying the coefficient of viscosity-range and the easurement-range of temperaturesand pressures, then we can choose the effective and efficient method to be developed
Analysing Threshold Value in Fire Detection Algorithm Using MODIS Data
Get PDFAbstract - MODIS instruments have been designed to include special channels for fire monitoring by adding more spectral thermal band detector on them. The basic understanding of remote sensing fire detection should be kept in mind to be able to improve the algorithm for regional scale detection purposes. It still gives many chances for more exploration. This paper describe the principle of fire investigation applied on MODIS data. The main used algorithm in this research is contextual algorithm which has been developed by NASA scientist team. By varying applied threshold of T4 value in the range of 320-360K it shows that detected fire is significantly changed. While significant difference of detected FHS by changing T threshold value is occurred in the range of 15-35K. Improve and adjustment of fire detection algorithm is needed to get the best accuracy result proper to local or regional conditions. MOD14 algorithm is applied threshold values of 325K for T4 and 20K for T. Validation has been done from the algorithm result of MODIS dataset over Indonesia and South Africa. The accuracy of MODIS fire detection by MOD14 algorithm is 73.2% and 91.7% on MODIS data over Sumatra-Borneo and South Africa respectively
Dropped in Capacity and Traffic Speed of Urban Arterial: A Case Study at U-Turn Section in Aceh Province, Indonesia
Get PDFAbstract - Dropped in traffic capacity and travel speed during congestion were studied at a u-turn section on an arterial road in Indonesia. Traffic characteristics during congestion were analyzed using oblique cumulative plots and breakdown method. Both approaches are time series treatment between cumulative vehicles arrival versus time contracted from data recorded by video tape. Studies were conducted in both morning and evening peak hours on three regular weekdays. This study found traffic breakdown condition during the peak periods; the breakdown lasted on average 40 minutes. It was found that capacity during traffic breakdown drops in the range 8-9 percent from the before-breakdown capacity. Similarly, during the breakdown, speed drops on average 10 percent from the before condition. Several alternatives were selected and tested for improving existing conditions. It was found that adding a 50m pocket lane would help improving the existing situation by reducing the delay to 69 percent, increasing speed to 39 percent, and improving capacity to 11 percent compared to the result of simulation an existing conditio
On the Oscillation of the Generalized Food-Limited Equations with Delay
Get PDFAbstract - The objective of the paper is to find conditions for the oscillation of the food-limitedequation. We established conditions for the oscillation of all solutions of the generalized foodlimitedequation by transforming the equation to a non-linear delay differential equation and then toa scalar delay differential equation and using the property of the scalar delay differential equation toobtain our result. Similarly we establish conditions for the oscillation of all solutions of the foodlimitedequation with several delays by transforming the equation to a scalar differential equation toobtain the oscillatory property
Electrochemistry Study on PVC-LiClO4 Polymer Electrolyte Supported by Bengkulu Natural Bentonite for Lithium Battery
Get PDFAbstract In this research bentonite was used as filler to produce polymer electrolyte (PVCLiClO4). Some weight variation of bentonite have been made by addition, such as 0% wt/wt; 5% wt/wt ; 10% wt/wt ; 15% wt/wt ; 20% wt/wt ; and 25% wt/wt of bentonite to the mixture of 0,5 gram of PVC and 0,125 gram of LiClO4. Ionic conductivity of polymer electrolyte was tested using impedance spectroscopy. The result of the research was showed that a mixture of PVCBentonite( 10% wt/wt)-LiClO4 gives the highest ionic conductivity (4,86 x 10-3 S.Cm-1). This result indicated that the presence of natural bentonite can be used as a filler in the current composite polymer electrolyte and can increase the ionic conductivity of the polymer electrolyte