Aceh International Journal of Science and Technology
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Isotherm and Kinetic Adsorption of Cadmium (Cd) onto Biosorbent Made from Kepok Banana Peel (Musa Acuminata balbisian): The Effect of Activator Type and Biosorbent Dosage
Full text linkThe present study determined the isotherm and kinetics model of the cadmium adsorption process onto a biosorbent made from kepok banana peel (Musa Acuminata balbisian). The experiments were carried out in batch process, laboratories scale, room temperature, pH of Cadmium of 4, volume of Cd solution of 20 ml, and biosorbent size particle of 60 meshthe biosorbent produced using chemical activation method onto dry banana peel. The variation in this research was the type of activator (H3PO4 and H2SO4) and the biosorbent dosage (1, 1.5, and 2 g). The experimental data was used to calculate the Langmuir and Freundlich isothermKinetics analysis based on pseudo-first-order and second-order kinetics models. The best condition of the cadmium removal occurred at 90 minutes of contact time and 2 g dosage for H2SO4 and H3PO4 activators. Cadmium biosorption was in accordance with the Langmuir isotherm and pseudo-second-order kinetic model. The linear equation obtained is positive, with the maximum adsorption capacity and the affinity constant. Cadmium adsorption onto banana peel biosorbents followed the Langmuir adsorption isotherm pattern, so chemical adsorption occurred in this study. Cadmium adsorption kinetics onto biosorbent that activated with an acid activator of H3PO4 and H2SO4 followed the pseudo-second-order kinetic model. The best condition of the cadmium removal occurred at 90 minutes of contact time and 2 g dosage for H2SO4 and H3PO4 activators. Cadmium biosorption in this study was in accordance with the Langmuir isotherm and pseudo-second-order
Assessment of Safety Measures and Operational Challenges of Inland Waterway Transport along Oron - Calabar Route, Nigeria
Full text linkThis study assessed the safety measures and operational challenges of inland waterway transport along the Oron - Calabar route. Observation and structured questionnaires were used for the collection of data. Quantitative data was analyzed using descriptive statistics, while qualitative data was coded and analyzed using the 4-point Likert scale, which was converted to a relative importance index (R.I.I.) for each factor, posing a challenge to operators. The result showed that safety equipment was provided onboard boats by operators. The R.I.I. computed showed that boat and engine replacement (R.I.I. = 0.874) was the most challenging factor, while water hyacinth (R.I.I. = 0.418) was the least. Other challenges were frequent bad weather conditions, high running costs, floating logs and debris, extortion by law enforcement agents, difficulty making headway against the opposite current, high cost of safety equipment, passengers' refusal to adhere to safety measures, and poor berthing facilities in their order of impact. Proper funding and enforcement of safety measures are hereby recommended
Impacts of Land Cover Changes on Land Surface Temperature Using Landsat Imagery with the Supervised Classification Method
Full text linkLand cover changes affecting the area's ecology align with the development and increase in urbanization. Tarogong Kidul Subdistrict, Garut Regency, experienced changes in the land cover which changed the soil surface temperature. This study aims to determine the relationship between changes in land cover and land surface temperature. This study used Landsat 8 Surface Reflectance Tier 1 satellite imagery to extract information on the Normalized Difference Vegetation Index and process ground surface temperatures for three periods, 2014, 2017, and 2020, and the guided classification method. Image collection and processing were carried out using Google Earth Engine and software. ArcGIS Pro. The distribution of land surface temperature was then correlated with changes in the NDVI (value of the land cover vegetation index) using simple linear regression analysis and spatial correlation. This study reveals that land cover change is closely related to an increase in soil surface temperature, as indicated by the rise in soil surface temperature in areas experiencing land use change. The results of the linear regression analysis (84.49%) showed that changes in land cover and the greenness index of vegetation were the most critical driving factors for changes in soil surface temperature
Adsorption of Phosphate from Aqueous Solution by Calcination of Silicified Coal: Kinetic and Isotherm Studies
Full text linkSilicified coal (SC) consisting of SiO2 is a promising raw material for adsorbent. The present study aimed to utilize silicified coal bottom ash (SCBA) adsorbent by calcination of the SC at temperatures of 600, 800, and 1000 oC for 1 hour. The FTIR result showed that the SCBA_600, SCBA_800, and SCBA_1000 had chemical functional groups such as the asymmetric Si-O-Si, the symmetric Si-O-Si and Si-O-Si bond rocking for adsorption of phosphate (PO4 3) with the lowest percentage of transmittance of SCBA-1000. The adsorption test showed that rapid adsorption occurred in the first 10 minutes of contact time, and it did not change significantly for the rest of contact time until reaching an equilibrium time of 30 min. The PO4 3 adsorption efficiency and capacity fluctuated over the initial PO4 3 in solution in the 60.02480.29 mg/L range. The highest PO4 3 adsorption efficiency and capacity were at 480.29 mg/L, 95.49 %, and 45.86 mg/g, respectively, using the SCBA-1000. The adsorption kinetic fitted better to the pseudo-second-order kinetics model (average R2 = 0.999) with the adsorption capacity of 45.454, 45.662, and 45.872 for the SCBA_600, SCBA_800, and SCBA_1000, respectively, and the PO4 3 adsorption rate was 0.0007, 0.0008 and 0.001 g/mg.min, respectively. The adsorption isotherm followed Langmuir model (average R2 = 0.873), with the adsorption capacity being 2.357, 1.198, and 8.196 mg/g, respectively, and the pore volume being 0.0316, 0.0364 and 0.2103 L/mg, respectively
The Performance of Concentrically Braced Frames (CBF) in Chevron V Brace and Diagonal Configuration by Considering Various Frame Heights
Full text linkConcentrically Braced Frame (CBF) is a structural system with high stiffness, so it is recommended to be implemented in earthquake-hazard areas. The stiffness in CBF is contributed by its diagonal component, which is called bracing. Bracing reduces lateral deformation on the frame system because of the earthquake and prevents heavy damage or failure of the structure. So far, several studies have been conducted. However, the effect of the frame height and the bracing configuration on the CBF performance has not yet been clarified. This study analytically investigated several models of CBF in Chevron V Brace and Diagonal configurations. Those models were prepared with different frame heights. The analyses were conducted by employing the cyclic load and considering yield displacement control in each model. The observation was emphasized on the load-displacement hysteresis curve, from which the performance of each model can be revealed. Three parameters of performance are evaluated: strength, stiffness, and dissipation energy. The analysis discovered that the Diagonal CBF performed better than the Chevron V Brace CBF by presenting a larger and more stable hysteresis curve, which is addressed to better energy dissipation. It is also discovered that reducing the frame height is suggested to enhance the CBF performance due to the earthquake
Evaluation of Land Capability and Land Use Direction in the Krueng Peusangan Hilir Sub-watershed, Bireuen Regency
Full text linkThe destruction of forests in watershed areas has now become a concern of many parties, resulting in floods, landslides, and droughts that continue to increase. Watershed damage is accelerated by increased utilization of natural resources due to population growth and economic development, conflicts of interest, and lack of integration between sectors between the upstream-middle-downstream areas. For this reason, it is necessary to assess land capability in a watershed so that land development follows the land capability class. The research was carried out in the Krueng Peusangan Hilir Sub-watershed, Bireuen Regency, Aceh, Indonesia, from October 2021 to February 2022, which is geographically located at 9558''00 - 9652''00 East Longitude and 506''00- 517 ''00" North Latitude. Land use in the study is dominated by dry land agriculture, covering an area of 19,100.28 ha with a topography area from 0-8% to 25-40%. A survey method by analyzing land capability classes at the study site was carried out for each land map unit (LMU) by comparing land conditions with the land capability evaluation Hockensmith and Steeles criteria (overlaid of determined thematic maps). The result shows that soil erodibility decreased linearly with increasing organic matter in the soil. Soils with high organic matter content have high erodibility. For the limiting factor on slopes in land capability classes found in II, III, IV, and VI class categories that are found in all LMUs, if these LMUs are used for agricultural cultivation, soil conservation measures are needed, such as making mound terraces or canal mound terraces, planting in strips and using mulch. The results show that the land capability classes consisted of 16668.30 ha in the land capability II class, 4184.06 ha land capability in the III class, 4524.91 ha in the land capability IV class, and 190.79 ha land capability VI class with a factor inhibiting soil erodibility (medium very high) and slopes (wavy - rather steep)
Preliminary Study of NFRP-Confined Concrete for Enhancing Compressive Strength
Full text linkA column is a structural element that carries axial compressive loads. This compressive axial load causes the shortening of the structural column. It causes the column to be subjected to a tensile force in its axis perpendicular to the compression axis. This tensile force causes the column to collapsereinforcement methods to improve the quality of concrete in resisting higher axial compressive loads. Strengthening the column with external restraints is expected to increase the strength of the concrete. The use of synthetic Fiber Reinforced Polymer (FRP) as a composite material for external restraint on structures is widely used for strengthening concrete structures. Considering the environmental impact, natural FRP materials have been developing nowadays. One of the natural fibers that have been researched and used as a composite material for Natural Fiber Reinforced Polymer (NFRP) is abaca fiber. This research aims to find the contribution of abaca fiber in increasing the compressive strength of confined concrete as a preliminary study. This study conducted the test by applying a compressive load to concrete specimens reinforced with NFRP restraints. Specimens were cylinders with a diameter of 150mm and 300mm in height. NFRP was applied at the cylinder circumference area (jacketing method) by using manual wet-layup techniques. The NFRP was investigated with variations in the number of NFRP layers. The results showed that NFRP-confined concrete has a higher compressive strength of 34.73% than the controlled specimen
Comparison Study the Modeling of Limiting Current in the Magneto Electrodeposition of Vanadium using Neural-Wiener Model and Feed Forward Neural Network
Full text linkVanadium has long been used as a corrosion-resistant coating, including as a metal alloy for battery cathodes. However, batteries discovered with non-smooth cathode surfaces due to the fabrication process have a short battery life. So, a cathode coating stage is required via the electroplating method under the influence of a magnetic field or Magneto Electro Deposition (MED). Knowing the limiting current in MED is very important because the optimum mass transport achieves at the limiting current (iB). The smoothest and most compact electrodeposit surface will occur at this limiting current. In this study, Feed Forward Neural Network and Neural-Wiener are suggested and compared as a nonlinear modeling approach to determine the ideal limiting current because of their strong capacity to anticipate the link between input and output from experiment data. The Levenberg-Marquadt optimization technique with hidden neurons was used to evaluate and compare the modeling capabilities of two neural networks, the Feed Forward Neural Network, and the Neural Wiener. The results of this study are presented as a comparison of the Mean Square Error (MSE) values obtained from the nonlinear modeling of two artificial neural network algorithms. The algorithm that models the ideal current limiting has the lowest MSE value (iB)
Urban Spatial Patterns of Banda Aceh Using a Shannon Entropy Method
Full text linkThe rapid development of Banda Aceh City has occurred mainly in suburban areas. The impact is that spillover is a complex urban phenomenon that is difficult to measure. Policymakers need a simple method to control and evaluate urban sprawl. This study integrates Shannon's Entropy model with remote sensing and GIS to analyze the pattern of sprawl in each sub-district in Banda Aceh City based on two aspects of distance, namely distance to the city center and road network in order to illustrate the pattern of urban sprawl. The application of Shannon's Entropy method in Banda Aceh City in 2010-2020 can be seen in the Relative Entropy Matrix, which shows that the linear spreading pattern (Quadrant C) is more dominant in Banda Raya Sub-district, Baiturrahman Sub-district, Kuta Raja Sub-district, Kuta Alam Sub-district, Lueng Bata Sub-district, and Syiah Kuala Sub-district. Meanwhile, the transmission pattern of Meuraxa and Jaya Baru sub-districts is in quadrant B, namely the longitudinal type transmission pattern (Radial); in 2020, Jaya Baru sub-district there was a change in the transmission pattern, namely a linear transmission pattern. In the Ulee Kareng sub-district, there is a change in the transmission pattern in 2020, which is in quadrant D, namely the leapfrog development pattern from the previous years, namely 2010 and 2015 in quadrant C with a linear transmission pattern. The spread pattern of Banda Aceh City tends to lead to the East, largely due to landform factors that are very suitable to be used as built-up areas
Investigation of Performance of Stone Fin Solar Still Absorber by Water Depth Variations
Full text linkPassive Solar is still suitable for Indonesia's islands and coastal areas. Various attempts have been made to increase the performance of passive solar stills, including using porous materials, fins absorber models, and making water in the form of a thin layer. This study aims to increase the distillate output and Efficiency of Solar still. This study's method compares stone fin solar stills absorbers using water depth variations of 1 cm, 2 cm, and 3 cm with conventional solar stills at a water depth of 1 cm. The study resulted in the distillate output of stone fin solar still absorber of 3.35 (liter/m2 .day) higher than the conventional solar stills 2.44 (liter/m2 .day) at a depth of 1 cm. The highest Efficiency of solar stills using the stone fin solar still absorbers is 58.45% higher than conventional solar stills, 43.60% at a depth of 1 cm. Solar stills with lower water depths resulted in higher distillate output and Efficiency. Solar stills using stone fin absorbent plates produce higher productivity and Efficiency than conventional ones