Aceh International Journal of Science and Technology
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Development of Rainfall-runoff Model Using Tank Model: Problems and Challenges in Province of Aceh, Indonesia
Get PDFAbtstract - Rainfall-runoff model using tank model founded by Sugawara has been widely used in Asia. Many researchers use the tank model to predict water availability and flooding in a watershed. This paper describes the concept of rainfall-runoff model using tank model, discuss the problems and challenges in using of the model, especially in Province of Aceh, Indonesia and how to improve the outcome of simulation of tank model. Many factors affect the rainfall-runoff phenomena of a wide range of watershed include: soil types, land use types, rainfall, morphometry, geology and geomorphology, caused the tank model usefull only for concerning watershed. It is necessary to adjust some parameters of tank model for other watershed by recalibrating the parameters of the model. Rainfall runoff model using the tank model for a watershed scale is more reasonable focused on each sub-watershed by considering soil types, land use types and rainfall of the concerning watershed. Land use data can be enhanced by using landsat imagery or aerial photographs to support the validation the existing of land use type. Long term of observed discharges and rainfall data should be increased by set up the AWLR (Automatic Water Level Recorder) and rainfall stations for each of sub-watersheds. The reasonable tank model can be resulted not only by calibrating the parameters, but also by considering the observed and simulated infiltration for each soil and land use types of the concerning watershed. Key words: rainfall-runoff model, tank model, infiltration, land use types, soil types, watershe
Impact of On-street Parking on Urban Arterial Performance: A Quantitative Study on Travel Speed and Capacity Deterioration
Get PDFAbstract - Traffic congestion has been a serious social and technical problem since the early years rapid motorization in Banda Aceh, Aceh Province of Indonesia. Urban arterial performance becomes the crucial concerns of many traffic engineers. Arterial performances were analyzed using oblique cumulative plots and breakdown method. The approaches are time series treatment between cumulative vehicles arrival versus time contracted from data recorded by video cameras. Investigations were conducted during both morning and evening peak hours on three regular weekdays for observing saturation condition in order to observe the maximum capacity under prevailing conditions. This study examined the impact of presence on-street parking on deterioration both travel speed and capacity. It found that capacity diminished slightly 10-13% (275-368vph) compared to the pre-breakdown condition. Likewise, during the breakdown, speed dropped about 13-19% (3-5kph) controlled by pre-breakdown as well. The simulation software so called VISSIM 5.30 was governed to estimate the measurement of effectiveness (MOEs) by removing on-street parking from a site of study. The MOEs reveal that removing on-street parking able to reduce average delay approximately 12 sec/veh (32%) and increase speed about 5kph (24%). Keywords: Arterial performance, pre-breakdown, breakdown, travel speed, capacity, on-street parking, simulation, VISSIM 5.30, MOEs
Response of Some Biochemical and Mineral Constituents of the Postharvest Mango (Mangifera indica L.) Influenced by Different Levels of Bavistin DF
Get PDFAbstractAn investigation was carried out with the postharvest mangoes (viz., the Langra and the Khirshapat) treating with different levels of Bavistin DF solution (namely, 250, 500, and 750 PPM) for obtaining results on the biochemical and mineral content changes as well as storability of postharvest mango. The results of the experiments exhibited that only the single effect of varieties was found to be significant in most of the parameters studied. The Langra enriched a greater quantity of crude fiber, lipid, water-soluble protein, phosphorus, and potassium constituents over the Khirshapat. It is revealed that the expansion of mineral contents in the mango was intimately associated with ripening during storage. The results also noticed to be an increasing trend of lipid and protein content in mango pulp with the advance of storage period using Bavistin DF.Keywords: Postharvest mango; Biochemical constituents; mineral contents; Bavistin DF
Facility Location Modeling in Multi-Echelon Distribution System: A Case Study of Indonesian Liquefied Petroleum Gas Supply Chain
Get PDFAbstract -This paper presents model of Indonesian LPG supply chain by opening new facilities (new echelon) taking into account the current facilities. The objective is to investigate the relation between distribution costs such as transportation, inventory cost and facility location in Indonesian multi-echelon LPG supply chain. Fixed-charged capacitated facility location problem is used to determine the optimal solution of the proposed model. In the sensitivity analysis, it is reported that the trade-offs between facility locations and distribution costs are exist. Results report that as the number of facility increases, total transportation and inventory cost also increase.Keywords: LPG supply, location, inventory, transportatio
Some Practical Guidelines for Effective Sample-Size Determination in Observational Studies
Get PDFAbstract- The purpose of this present study was to determine the right sample size in observational study which is focusing on medical or health sciences field. Sample size calculation is actually depends on the type of how the study is designed. For example different formulas are used to calculate the sample size in different type of the study. In this article, the formula of single proportion and two proportions is discussed and an example from medical research, which may contribute to the understanding of this problem, is presented
Development of Rainfall-runoff Modeling Using a Tank Model: Problems and Challenges in Province of Aceh, Indonesia
Get PDFAbtstract - Rainfall-runoff modeling using tank model founded by Sugawara has been widely used in Asia. Many researchers use the tank model to predict water availability and flooding in a watershed. This paper describes the concept of rainfall-runoff modeling using tank model, discuss the problems and challenges the use of tank model, especially in Province of Aceh, Indonesia and how to improve the outcome of simulation of tank model. Many factors affect the rainfall-runoff phenomena of a wide range of watershed include: soil type, land use types, rainfall, morphometry, geology and geomorphology, caused the tank model usefull only for concerning watershed. It is necessary to adjust some parameters of tank model for other watershed by recalibrating the observed and simulated discharges. Rainfall runoff modeling using the tank model for a watershed scale is more reasonable focused on each sub-watershed by considering soil types, land use types and rainfall of the concerning watershed. Land use data can be enhanced by using landsat imagery or aerial photographs to support the validation the existing of land use type. Long term of observed discharges and rainfall data should be increased by set up the AWLR (Automatic Water Level Recorder) and rainfall stations for each of sub-watersheds. The reasonable tank model can be resulted not only by calibrating the observed and simulated discharges, but also by considering the observed and simulated infiltration for each soil and land use types of the concerning watershed
Determining Groundwater Recharge from Stream Flow with Seasonal Recession Method
Get PDFAbstract- Volume of groundwater recharge showed a picture of a watershed to determine the flow instability due to the physical characteristics of the watershed and precipitation. Many methods had been constructed to understand the dynamic movement of water discharge. One of them was the analysis of the stream hydrograph with Seasonal Recession Method. Information about groundwater recharge condition at several sub watershed in Krueng Peusangan Watershed was really needed in management of watershed for sustainable water resources. The study aimed to determine groundwater recharge from stream flow with seasonal recession method was conducted in Krueng Peusangan watershed, Aceh Province, Indonesia. The results showed that the trend pattern of the stream hydrograph could be explained using the exponential function where the dots lowest discharge that is the end of the recession (y) than any period of time on stream hydrograph semi logarithmic (x). The pattern of results that occurred in the watershed of Krueng Peusangan: (A) Krueng Seumpo had a trend for y = 9.2x-0.35, (B) Simpang Jaya for y = 559.7x-0.5, (C) Beukah village for y = 142x-0.32, (D) Sub watershed of Lut Tawar (Wih Nareh) for y = 1.3x-0.12and (E) Sub watershed of Teupin Mane (Krueng Teumbo) for y = 1.94x-0.42. It also showed that the location of A, B, C, E had a higher slope and a decreased recharge pattern compared to the location of D (sub watershed of Lut Tawar) that tended to flat. The volume of groundwater recharge that occurred in a region (A and D) increased while the other location was very volatile. Moreover, recharge instability occurred in Krueng Teumbo. Therefore, it needed a clear direction for land use and functions of forests, especially in the recharge area, in order to maintain the balance of the hydrological cycle, and the quantity of groundwater.Keywords: groundwater recharge, seasonal recession method, base flow, stream flow, water resource
Changes in Color and Physiological Components of The Postharvest Mango (Mangifera indica L.) Influenced by Different Levels of GA3
Get PDFAbstract - This experiment consisted of two popular mango varieties in Bangladesh (viz., Langra and Khirshapat) and four different levels of Gibberellic acid (GA3) solution, namely control, 100, 200 and 400 ppm. The two factors experiment was assigned in randomized complete block design with tree replicates. Data obtained from various biochemical analyses in terms of physicochemical properties and shelf life of postharvest mango, were recorded and statistically analyzed for comparison among the mean values using DMRT and LSD. The results of the experiments exhibited that only the single effect of varieties was found to be significant in most of the parameters studied. Variety the Langra performed better in accumulating higher quantity of dry matter, ash, vitamin c content in all four experiments over Khirshapat. On the other hand, the Khirshapat showed better performance in achieving higher quantity of moisture, progressively lost physiological weight as well as extended shelf life and delayed skin color changes than Langra at all the storage duration.Keywords: Postharvest mango; Gibberellic acid; physiological components
Vectorial Formalism of Polyphase Synchronous Machine With Permanents Magnets
Get PDFAbstract- This paper presents a mathematical model that transforms the real machine to fictitious machines and our goal is to simulate these and see the behavior of these machines in load. The polyphase machines are developed mainly in the field of variable speed drives of high power because increasing the number of phases on the one hand allows to reduce the dimensions of the components in power modulators energy and secondly to improve the operating safety. By a vector approach (vector space), it is possible to find a set of single-phase machine and / or two-phase fictitious equivalent to polyphase synchronous machine. These fictitious machines are coupled electrically and mechanically but decoupled magnetically. This approach leads to introduce the concept of the equivalent machine (multimachine multiconverter system MMS) which aims to analyze systems composed of multiple machines (or multiple converters) in electric drives. A first classification multimachine multiconverter system follows naturally from MMS formalism. We present an example of a pentaphase (polyphase) synchronous machine for a simulation and study the behavior of the machine load.Keywords: Polyphase machines, multimachine concept, vector space, eigenvectors, eigenvalues, pentaphase machine
A Study on Learning Pre-Algebra Using Interactive Multimedia Courseware Within Collaborative Learning Set-Up and E-Mail Interactions
Get PDFAbstract Many students at diploma level are weak in mathematics even after spending eleven years in Malaysian education system. However, throughout the world there are research studies been done with mixed results using technology and collaborative learning. The objective of this paper is to analyze the effect of learning pre-algebra using interactive courseware with collaborative learning by using STAD set ups with interactive courseware using e-mail facilities during team discussion only. Quasi experimental type research was used. The gain score (differences between post and pre test) between the two equivalent groups were obtained. Diploma Information Technology first year students in two different intake years 2009 and 2010 in UTHM were employed. t-test results revealed the second group using e-mail is statistically significantly inferior to the group using purely interactive multimedia courseware CDiCL only with STAD team discussion. On average participants experienced higher gain scores in the first group (Mean = 3.28, SE=0.433), than participants in the second group (M=0.77, SE=0.354). This difference was statistically significant (t (74) = 4.51,