Aceh International Journal of Science and Technology
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Effect of Silica Addition on Mechanical Properties of Eggshell-Derived Hydroxyapatite
Full text linkEggshell is a solid waste that is available in abundance but is being left unused. Eggshell containing calcium in a high amount. Calcium can be used as a precursor for hydroxyapatite (HAp). Modification of HAp with SiO2 is expected to improve its low mechanical properties for biomedical applications. In this study, HAp is synthesized from the eggshell. Then, it was modified by adding SiO2 utilizing the coprecipitation method with concentrations of 10%, 20%, 30%, and 40%, respectively. The HAp and HAp/SiO2 were characterized using; X-ray diffraction and Fourier transform infrared spectroscopy. The analysis HAp and HAp/SiO2 were density, compressive strength, and hardness. The best mechanical properties of HAp/SiO2 were characterized using SEM-EDS. The HAp were prepared successfully with a ratio of Ca/P was 1.673, close to the theoretical 1.67. The addition of SiO2 caused a decrease in crystallite size and density but increased compressive strength and hardness. The best mechanical properties of HAp/SiO2 were obtained with SiO2 of 30% and 40% with similar values
The Implementation of Machine Learning in Lithofacies Classification using Multi Well Logs Data
Full text linkLithofacies classification is a process to identify rock lithology by indirect measurements. Usually, the classification is processed manually by an experienced geoscientist. This research presents an automated lithofacies classification using a machine learning method to increase computational power in shortening the lithofacies classification process's time consumption. The support vector machine (SVM) algorithm has been applied successfully to the Damar field, Indonesia. The machine learning input is various well-log data sets, e.g., gamma-ray, density, resistivity, neutron porosity, and effective porosity. Machine learning can classify seven lithofacies and depositional environments, including channel, bar sand, beach sand, carbonate, volcanic, and shale. The classification accuracy in the verification phase with trained lithofacies class data reached more than 90%, while the accuracy in the validation phase with beyond trained data reached 65%. The classified lithofacies then can be used as the input for describing lateral and vertical rock distribution patterns
Physical Characteristics of Krueng Seunagan Watershed and River Storage Capacity Against Peak Discharge
Full text linkPeak discharge information is indispensable for flood control planning by taking into account the physiographic factors of the watershed. Flood occurs because the capacity of the watershed and river channels is smaller than the flood discharge. One of the causes of rivers' reduced flood flow capacity is vegetation cover and land use that cannot store rainfall. Thus, this paper aims to determine the peak discharge from the watershed's physical characteristics and land-use changes by comparing the river storage capacity in the Krueng Seunagan watershed. The rational method is used to calculate the peak discharge. Some of the data used in this study are the shapefile map provided by Geospatial Information Agency, land use, rainfall, soil types, and Landsat 8 OLI/TIRS digital imagery. Analysis of the physical characteristics of the watershed consists of morphology and morphometry. Land use in the area of the Krueng Seunagan watershed increased the peak discharge during the observation year (2003-2017). Besides the land-use factor, discharge is also influenced by high rainfall intensity and runoff coefficient obtained from land use analysis. In the Krueng Seunagan watershed area, the C value obtained was 0.0505 0.0720, indicating that the Krueng Seunagan watershed area was classified as good or harmless. The river flow density of 0.53 belongs to the medium category. The river flow increases and decreases in the flood water level, which is neither too fast nor too slow. The roundness index of the Seunagan watershed of 1.0004 indicates that the basins are widened or circular and, consequently, the rate and volume of surface runoff are fast. Krueng Seunagan watershed runoff coefficient increased by 42.51% and rainfall intensity by 37.05%, while discharge increased by 95.31%. The discharge capacity that the Krueng Seunagan River Basin can accommodate from the measurement results in the downstream watershed is 158.47 m3/sec. While the peak discharge using the rational method gets a value that varies in each year of observation from (2003-2017). The peak discharge value in 2003 amounted to 183.52 m3/sec, and the highest in 2017 amounted to 358.44 m3/sec. This shows that the river holding capacity in the Krueng Seunagan watershed will not accept the amount of peak discharge, and consequently, the flood will always occur
Space Adequacy Analysis Based on Population Pressure National park Area (Case Study : Putri Betung Sub District, Gayo Lues, Aceh)
Full text linkThe land requirement for Putri Betung Sub District in Gunung Leuser National Park (GLNP) area kept increasing along with the population growth. The population density in the Putri Betung Sub-district was driven by the need for cultivation and residential area along the GLNP conservation boundary. This study aims to analyze the space adequacy for Putri Betung Sub-District in the GLNP area based on the population pressure prediction for 20 years. The research method was conducted by field survey using remote sensing, interviewed the residents, and analyzed the population pressure index using the Soemarwoto formula. ThePopulation Pressure Index (PPI)forthe cultivation area was determined from 13 villages in Putri Betung Subdistrict and shows that 12 villages had a PPI 1 value (population pressure was over the land carrying capacity limits). Only one village had PPI 1 (population pressure less than the land carrying capacity. Based on data surveys obtained, the cultivation area set in the Putri Betung area was no longer sufficient for population, resultingfrom the expansion in the GLNP area of 4,776.97 ha. Meanwhile, predictive analysis on space adequacy for people living decently in Putri Betung Sub District for 20 upcoming years is 6117.15 ha. In conclusion, 12 out of 13 villages in the Putri Betung SubDistrict havePPI 1 value, which is inversely proportional to the land carrying capacity. The PPI values could result in other pressures on the ecology and biodiversity conservation in National Park. It is suggested that the government need to surpassthe pressure by making new policy on peoples resettlement, expanding the cultivation area, or shifting people's livelihoods
The Effect of Low-Density Poly Ethylene (LDPE) Towards Plastic Oil Quality
Full text linkNowadays, the use of plastics is inseparable from daily life activities for both industrial commercial and household needs. Every year, an average individual consumes 700 plastic bags. Furthermore, the major types of plastic pollutants are High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE). The nature of LDPE plastic makes it very difficult to undergo decomposition. Subsequently, efforts to overcome this problem have been carried out by several methods of processing or utilizing its waste through pyrolysis. This s tudy aims to determine the effect of the quality of LDPE plastic waste on the plastic oil produced from the pyrolysis process. Based on their chemical compounds, all plastic oils produced were categorized as carbon compounds instead of hydrocarbons. Althou gh, from the quality of the LDPE plastic used, the process produced gasoline, naphtha, and kerosene, the quality of each oil was different. Therefore, the higher the quality of the LDPE plastic used, the better the quality of the oil produced
Developing a Computer Simulation Game as a Training Tool for Mine Self-Escape in Underground Coal Mine
Full text linkGaming technology has been growing these years rapidly. The game engines have the capability of creating a very realistic virtual environment model. This technology can also be used for mining purposes. In this research, the game engine is specifically used to develop a mine self-escape simulation game for training purposes. The game engine which is used to develop the simulation game is Unreal Engine 3. The main advantage of using such a simulation game as a training tool is because it allows the trainee to experience a dangerous situation while not being put in danger. This kind of training is considered better than conventional briefing, normally conducted by showing a video or pamphlet. Studies have shown that people retain more information when they are involved interactively in the learning process. In this research, a computer simulation game as a training tool for underground coal mine self-escaped has been successfully created using fire scenarios. The player/trainee should follow some procedures to get to the safety zone
Evaluation Of Interfacial Adhesion Between Concrete Substrate And Self-Compacting Concrete As A Repair Material
Full text linkThis paper focuses on using self-compacting concrete (SCC) as a material in the repair technique given the advantages it presents in the fresh state, namely: stability, homogeneity, and deformability, because it perfectly matches the shapes of the surfaces to be repaired. The interest is mainly focused on the evaluation of bond strength at the interface: Repair/Substrate. The assessment is made via a repair applied to a half-cylinder of the ordinary concrete substrate (OC), by using as a repair material two classes of self-compacting concrete (SCC) of different strength (30 and 40 MPa), the interface bond strength obtained in this case is compared to that of a half-cylinder (BO) repaired with vibrated concrete (OVC) used as a reference control concrete. The rheological properties of the (SCC) used were determined with the aid of the Slump-flow, L-Box, V funnel, and stability under sieve tests. Mechanical properties include compressive strength, and tensile strength. The test to assess the interface bond strength of the specimens is based on a splitting tensile test (indirect tensile). Finally, to determine the type of failure produced after the test. The results obtained showed that self-compacting concrete appears to be a very promising material in the repair and rehabilitation of concrete structures. SCC offers good interfacial bonding and therefore gives satisfactory interface bond strengths
Characteristics of Sediment at Littoral Zone of Anoi Itam Beach (Eastern Weh Island, Indonesia) Based on Seasonal Changes
Full text linkAnoi Itam Beach (AIB), located in the eastern part of Weh Island, has the sediment characteristic of dark-sand color. Climatologically, the beach is influenced by two seasons, i.e., south-west (SW) monsoon and northeast (NE) monsoon. Sediment data are collected in the upper and lower littoral zones that are divided into six stations alongshore. Data were collected on October 2016 and April 2017, representing post (SW) monsoon and post-NE monsoon events. To examine the effect of seasonal, sediments statistics, e.g., mean, sorting, skewness, and kurtosis, have been calculated. AIB was characterized as well sorted to poorly sorted sediment. Sediments were identified as mesokurtic in October, varied to leptokurtic and platikurtic in upper littoral and lower littoral, respectively, in April. Grain size in both upper and lower littoral had increased from October to April. The impact on sediment sortation was minor due to the seasonal difference. Sediments in the upper littoral vary slightly skewed than lower littoral, which response to a more positively skewed during seasonal change from SW-monsoon to NE monsoon. The results suggested that lower littoral provide high variability of sediment characteristics depend on the season
Evaluation of Farmers Management Practices of Arabica Coffee Plantation Across Altitude for Climate Change Adaptation Strategies in Aceh, Indonesia
Full text linkThe productivity of Arabica coffee in low-altitude areas in Aceh have been declined, caused by an increase in temperatures, and by pests and diseases attack. This study aims to develop adaptation strategies to climate change in Aceh trough understanding how coffee productivity correlates with the management practices across the altitude. To find out a correlation between farming practices variables and coffee productivity, Spearman's rank test was used. To assess whether farming practice explanatory variables affected by the altitudes, a non-parametric with the Kruskal-Wallis Test, with Tukeys post-hoc test (P0.05) with Chi-square distance were used. The results showed that coffee productivity was positively and significantly correlated to pruning, weeding, application of fertilizer, and application of pest and disease control, but was not to coffee plant density, sustainability certification, land conservation, and age of the coffee plant. Adaptation strategies for farmers in higher altitudes are to maintain the coffee plant density as well as shade density at an optimum level, followed by increasing management practices such as pruning, weeding, application of fertilizer, and pest and diseases control; in lower altitudes, those are to increase shade density both with Leucaena and multipurpose plants such as avocado and citrus, as well as increasing management practices such as land conservation, pruning, weeding, application of fertilizer and pest and diseases control. In middle altitudes, those are to maintain and improve management practices applie
Characteristics of Pozzolan and Composite Portland Cements for Sustainable Concrete's Material
Full text linkTo support sustainable materials, the ordinary Portland cement production has been reduced since it left a high carbon footprint during manufacturing. As an alternative, the use of pozzolan Portland cement and composite Portland cement has been encouraged because they are more environmentally friendly. This paper examines some characteristics of cement made from pozzolan Portland cement (P.P.C.) and composite Portland cement (P.C.C.). The testing procedures were carried out on chemical and physical testing on P.P.C. and P.C.C. In addition, the mechanical testing of concrete made from both types of Portland cement and their combinations were conducted under compression load. Furthermore, the surface hardness of the concrete was evaluated using a rebound hammer measurement. Concrete testing was conducted after the curing age of 7, 28, and 42 days. According to chemical examination, P.P.C. has higher silica (SiO2) and iron (Fe2O3) than those of P.C.C., whereas P.C.C. has a higher lime (CaO) content. Compared to P.P.C., P.C.C. shows faster initial and final setting time. This result is proportionally influencing the strength development of concrete. P.C.C. concrete offers significant strength development at an earlier age. Meanwhile, P.P.C. concrete reacts slower at an earlier age, but it improves the compressive strength at a later age. The mix combination of 50% P.P.C. and 50% P.C.C. in concrete shows the highest average compressive strength and surface hardness. This combination achieves the average compressive strength of 30.27 MPa, 35.27 MPa, and 35.93 MPa respectively for 7, 28, and 42 days curing time. Furthermore, this concrete also shows the most remarkable characteristics of Young's modulus and surface hardnes