Jurnal Teknosains
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Proses difusi relativistik melalui persamaan langevin dan fokker-planck
No full textBrownian motion theory is always challenging how to describe diffusion phenomena with the main issue is how to extend the classical theory of Brownian motion to the special relativity framework. In this study, we formulated dynamics and distribution of a Brownian particle in relativistic framework by using Langevin and Fokker-Planck equation. By representing Brownian particle dynamics by Langevin equation, the velocity curves were dependent on the presence of viscous friction coefficient (heat bath), and were used generalized in special relativity theory, A relativistic Langevin equation reduces to the classical theory at low velocities. Likewise, the distribution of Brownian particles is represented as a stationary solution of the relativistic Fokker-Planck equation. From numerical results, we found that the probability density in the relativistic Fokker-Planck equation for was reduced to the standard Fokker-Planck equation in Netownian classical theory. For the calculation result showed that the Hanggi-Klimontovich approach has a consistent result to the relativistic Maxwell distribution. This work could open a promising interpretation to formulate the diffusion phenomena into general relativity theory
Optimasi unjuk kerja pada sistem pendinginan adsorpsi dengan siklus pemanasan-ulang kombinasi
No full textThe adsorption refrigeration system is a cooling system that offers several benefits, including being environmentally friendly due to the very small amount of global warming effect given, the lack of potential for ozone depletion, the low energy consumption of its operation, the low heat source used in its operation and good for reducing gas emissions on earth. This paper describes a combined reheating adsorption refrigeration system with three heat exchangers, as well as operating modes. The operation of the adsorption refrigeration system with combined reheating is schematically described with operational modes and diagrams. This adsorption cooling system is made up of three heat exchangers (H), one evaporator, and one condenser. The combination cycle is intended for heat exchanger systems that operate in a reheat cycle (H1 and H2) and a non-reheating cycle (H3). This paper also discusses system cycle time optimization. Research to get the optimum value of cycle time in this system is still rarely done and therefore optimization of cycle time is carried out on the system to get the best performance. The PSO (particle swarm optimization) program is paired with the MATLAB program to simulate the performance of the system under discussion while also enhancing its performance. The goal of this work is to use simulation to determine the optimal system performance versus the overall cycle time, which includes adsorption/desorption time, pre-cooling and pre-heating time as well as mass recovery time. Getting the best value for the entire cycle time is made possible by fusing the simulation of the system's process performance with performance optimization. As a results, the greatest increase in the optimization results' performance value occurs at a heat source temperature of 55ºC with a longer time to achieve optimal performance
Jejak karbon pada tahap operasional agro-eduwisata kota mataram menggunakan pendekatan penilaian daur hidup
No full textClimate change is one of the global issues that require the participation of all stakeholders for handling. In addition, the climate change issue is listed as one of the sustainable development goals (SDGs). The Government of Mataram city, as one of the stakeholders, has committed to involve the climate change consideration into its planned program, including the development of agro-edutourism facility. This study aims to calculate a carbon footprint of agroedutourism facility during the operational stage in order to implement the Greenhouse Gas (GHG) emission reduction strategy. The method used is a life cycle assessment approach with ReCiPe analysis, and the functional unit is an annual carbon footprint per m2 area of agro-edutourism. The study showed that the total carbon footprint per m2 was 2.88 KgCO2-e per annum with the primary environmental hotspot was fossil fuel utilization in energy source of agro-edutourism facility (Electricity State-own Company) and visitor vehicles. Therefore, some strategies could be applied for reducing the carbon footprint, such as increasing the utilization percentage of renewable energy (solar panel), using energy-saving bulbs, preparing the facilities for zero-emission vehicles, and applying the green building concept or design. Further research is required to assess the energy management concept from the technical feasibility aspect and economic aspect for complimenting this study
Optimization of chitinase production from bacillus cereus smg 1.1 using response surface methodology
No full textShrimp shell waste are potential to be processed further into value-added products, such as N-acetylglucosamine (GlcNAc). In the production of GlcNAc, biological approach is preferred and environmentally friendly to chemical treatment. Chitinase is an enzyme that plays a vital role in bioprocessing of shrimp shell waste into GlcNAc. Previously, Bacillus cereus SMG 1.1 was isolated from fermented shrimp paste (terasi) and showed the ability to produce chitinase. This study was designed to determine the optimum medium for the production of chitinase from B. cereus SMG 1.1 through the Response Surface Method (RSM) using a factorial design with 15 treatments. The optimization of the media was carried out by determining the factors that influence the production of chitinase through the Plackett-Burman design followed by optimization of the concentration of the media through the Box-Behnken design. The test was designed to assess the effect of the independent variables on chitinase activity. Placket Burman analysis shows that colloidal chitin, fructose, and MgSO4.5H2O were the significant components in the medium affecting the production of chitinase by B. cereus SMG 1.1. Box-Behnken analysis developed a linear model capable of predicting the response. The highest response value was achieved at a concentration of 0.75% fructose, 1.5% colloidal chitin, and 0.075% MgSO4.5H2O resulted in optimum chitinase activity of 0.0016 U/ml
Organizational internal and external resources as drivers of success in product development: A conceptual model
No full textProducts succeed if they meet customer needs and expectations. However, the capability of a corporation or organization to achieve the success of its products is determined by many variables, including being able to exploit its internal and external resources. This study is aimed to test variables that generate impacts on successful products. With the aid of research tool Vosviewer, a bibliometric network is mapped based on Scopus data of previous publications. Then an in-depth analysis is conducted on variables that are identified with a systematic review technique, in which corporational internal and external factors that have great significance on the success of products are grouped. By virtue of this research, a conceptual model is built to describe how corporational internal and external resources affect product success. It is found driving forces in promoting success of products are four internal resources like product characteristics, organization & management characteristics, innovative, and knowledge sharing, and one external resource market characteristics. The conceptual model built in this study would serve as a model for measuring the success of product development in the subsequent studies
Analisis spasial temporal zona rawan kekeringan lahan pertanian berbasis remote sensing
No full textA mapping model of drought-prone zones for agricultural land based on Geographic Information Systems is needed to determine the distribution of drought vulnerability levels that occured in Bantul Regency, DI Yogyakarta. This study aims to determine the estimated area of agricultural land drought based on the interpretation of aerial images. This study compares the performance of the drought potential index of agricultural land using the Normalized Difference Drought Index (NDDI) algorithm based on remote sensing technology/ Landsat 8 satellite imagery to identify the estimated zones indicated for agricultural land drought that occurred in Bantul Regency, based on trends in spatio-temporal data with recording intervals from the 2015 until 2020 data representative during the dry season. Comparisons were made by looking at the performance between indices extracted from Landsat 8 imagery data based on the value of the green vegetation parameter/ Normalized Difference Vegetation Index (NDVI) and the soil and vegetation moisture parameters/ Normalized Difference Water Index (NDWI). The method used in this research is descriptive correlative method: quantitative and qualitative deductive using geostatistical indicators based on big data analysis to measure and compare various data variables spatio-temporal. The distribution of agricultural land drought through the NDDI index transformation method on a normal, mild, moderate, to severe scale occurs in almost all areas of Bantul Regency. This happened, due to the influence of natural activities of the global climate phenomenon ENSO, the impact of the transition of the El Nino phenomenon to La Nina (wet drought) which was more dominant in 2016. The average area affected by drought in Bantul Regency on a normal scale affected was ± 6.500,49 ha, affected by mild drought was ± 17.192,16 ha, affected by moderate-scale drought was ± 8.636,155 ha, and affected by drought of heavy scale agricultural land was ± 2.407,485 ha
Efisiensi termal dan efektivitas produksi kondensor pada solar still terpadu
No full textWater is a basic human need that must be fulfilled. The need for clean water is increasing while the availability of clean water is limited, so researchers are trying to use sea water as raw material for fresh water. Sea water is an abundant source of water but still contains salt, therefore it is necessary to separate sea water and its salt content to produce fresh water or desalination, one way is to use solar stil. Solar stills are mostly used for desalination processes on the coast and remote area because they can be operated easily and can be manufactured at low cost. However, solar still has low productivity, so various studies have been carried out to increase desalination yields, such as the addition of a condenser. Aim of this study was to determine the thermal efficiency and effectiveness of the condenser on solar stills. The research was conducted in period March - May 2021. The materials used are aluminum with a length of 300 mm, a width of 300 mm and a thickness of 1.6 mm for the basin plate, double glass with a thickness of 3 mm for the top and sides of the solar still. The study was conducted indoor with radiation intensity using halogen lamps. The variables measured were water temperature, evaporation, inner glass surface, condenser, inlet and outlet of the condenser cooler using a fluke meter, radiation intensity using a solar power meter and desalinated water using a digital balance. From the results of the study, the average thermal efficiency of the condenser in the integrated solar still reached 83.94% and the desalination mass of seawater reached 451.32 grams with the effectiveness of condenser production of 96.4% and the correlation value of 0.99
Akurasi dimensi produk filamen 3d printing berbahan polipropilen menggunakan mesin ekstrusi
No full textAdditive manufacturing (AM) has been trending topic in industrial revolution 4.0. One technique and the most widely used AM is fused deposition modeling (FDM), which uses a melted filament and deposited it layer by layer. The common filaments used are made of PLA, PP, and ABS, which are available at the online market with variety of prices depend on the quality. It is an advantage if we can make these filaments. In filament manufacturing, the dimensional accuracy is one of the most important factors to comply with the existing 3D printers. The aim of this research is to fabricate a filament made of PP, then assessed the quality based on the accuaray of the targeted diameter of 1.75 mm. The manufacturing process used a self-made plastic extrusion machine. Variations were made on three variables with three levels each. There are (i) heater band temperature with a minimum and maximum range (150/170 oC, 155/175 oC and 160/180 oC), (ii) winding speed (13 mm/s, 16 mm/,s and 19 mm/s), and (iii) roll distance to the nozzle set point (200 mm, 500 mm and 700 mm). Taguchi L9 design was used to design the experiments and analysis.Minitab 19 was employed to find the S/N ratio and analysis the variance (ANOVA). The results of the analysis state that two parameters have a significant effect on the dimensions of the filament, i.e. temperature and roll distance to the nozzle, while, the winding speed has no dominat effect. The best accuracy of filaments diameter was achieved when applying a combination of temperature (160/180 ⁰C), the distance between the nozzle to the roll of 700 mm, and winding speed of 13 mm/s
Flash flood (Δ) risk and damage assessment in batu, East Java
No full textHydrometeorological disasters are showing an increasing trend in Indonesia. Flash floods are part of a hydrometeorological disaster that has a significant livelihood impact. Flash Flood is triggered by the intensity of extreme rain, several actions of mitigation can be taken by early warning systems, hazard and risk mapping, community preparedness, and climate change adaptation. So, how does future land use have an impact, and how much loss will result from the flash flood disaster in Batu City? The hydrometeorological disaster that occurred in Indonesia was the Batu Flash Flood. The Flash Flood occurred on November 4, 2021. The flash flood has a lot of impact on many locations, including the Bumiaji District and Junrejo District. Based on the disaster history recorded, the flash flood in Batu has only happened once, but the impact was quite big because there are many houses in the midstream of Bulukerto. Based on the losses caused, this can be the basis for efforts to control the spatial pattern of Batu City in the future. The methodology used in this study is risk assessment. While the risk study related to delta (Δ) the study of flash floods risk in spatiotemporal prevention uses the 2030 spatial plan for delta prediction (Δ), which can later predict the consequences of climate change and meteorological disasters from flash floods in Batu. The results of this study are the delta (Δ) of flash flood risk and the damage assessment of the flash flood that occurred in Batu.
Impact of slum upgrading to river water quality in Yogyakarta city, Indonesia
No full textDue to a lack of proper sanitation services, the disposal of residential wastewater from slum areas has become one of the river pollution contributors. In Yogyakarta slums were concentrated along the riverbanks of the Winongo, Code and Gajahwong rivers. Due to slum upgrading, slums have declined from 264.5 ha to 114.72 ha between 2016 and 2020. This research aims to determine the correlation between slum upgrading and river water quality. The data was acquired from the Government of Yogyakarta City, Indonesia, and examined using ten water parameters from 2013 to 2021. Using Pearson Correlation Coefficient and Spearman Rank, it was found that population density positively correlated with Total Coliform and Fecal Coliform (p<0.05). It was also seen that the slum ratio showed a positive correlation with BOD, COD, TSS, pH, and NH3-N (p<0.05). The number of WWTP had a positive correlation with PO4-P (p= 0.037), whereas the number of connected houses to WWTP reported a positive correlation with P04-P (p=0.028). In addition, a significant decrease in BOD, COD, NH3-N, pH, and TSS were found using the Paired t-test and the Wilcoxon Signed-Rank test. (p<0.05). Slum upgrading notably reduced organic pollutants and suspended solids. However, the performance of WWTP did not perform a maximal contribution to reducing PO4-P and Coliform; therefore, it is necessary to improve the performance. This study might be used to enhance the river and urban management in Yogyakarta City