BERKALA SAINSTEK
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254 research outputs found
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Generation of Fractal Objects with Iterated Function System on the Developments of Trellis Ornament Designs
No full textFractals are one of a mathematical concept that provides artistic value and is therefore widely used to design various kinds of objects. The purpose of this study is to obtain various trellis ornament designs generated from fractal objects. Some fractal objects that will be used are Koch Snowflake (m,n,c), Koch Anti-Snowflake (m,n,c) and dragon curve. The basic trellis pattern is built from basic geometry, namely line segments, rhombuses and elliptical curved lines with certain sizes. In this study, the generation of fractal objects was carried out using the Iterated Function Systems (IFS) method. In this case, IFS is carried out by utilizing Affine transformations, namely dilation, rotation and reflection. Related to the generation of the Koch Snowflake curve (m,n,c), an m-sided polygon with 3≤m≤5 is used and the side looping form uses an n-sided polygon with 3≤n≤5. The c value or the middle segment divisor used is 0.3; 0.2; and 0.19. The dilation scale on the dragon curve is 0.6≤k≤9.8 and the angle θ=90°. The iteration used to generate the Koch curve is 2 iterations while the dragon curve is 15 iterations. By taking several parameters, a trellis ornament design consisting of 5 patterns is obtained and each pattern has 3 variations of trellis motifs.
Optimization of Water Distribution Based on Head loss Analysis Using EPANET Software
No full textWater is a vital resource that supports various sectors of life, particularly agriculture. In irrigation systems, efficient water distribution is often hindered by pressure loss (head loss) caused by friction between the water flow and pipe walls. This study aims to analyze head loss in irrigation networks using the Darcy-Weisbach equation and compare the results with simulations conducted using EPANET software. The analysis involved manual calculations based on field discharge data and network simulations replicated in EPANET. The results showed an accuracy level of 80.69% with a relative error of 19.31%. Network modification was performed by increasing the pipe diameter in the primary channel (P1-P4), resulting in a uniform discharge of 0.04 L/s in secondary channels and 0.02 L/s in tertiary channels. This modification reduced the average head loss by 69.72%, indicating a significant improvement in water distribution efficiency
Numerical Solution of Anisotropic Diffusion with Localized Source Using Euler Scheme and Finite Element Method
No full textThis study investigates the numerical modeling of two-dimensional anisotropic diffusion processes involving a spatially localized and temporally limited energy or thermal source. The governing model is formulated as a parabolic partial differential equation, discretized in space using the Finite Element Method (FEM) with linear triangular elements, and in time using both explicit and implicit Euler integration schemes. To ensure spatial accuracy, a dense mesh configuration is employed, which has been shown to produce smooth and representative solution distributions. Simulation results demonstrate that the implicit Euler method exhibits superior numerical stability across various time step sizes, whereas the explicit method requires significantly smaller time steps to remain stable. Analysis of the transient regime reveals that the numerical solution gradually converges toward a steady-state configuration once the source is deactivated. These findings confirm that the combination of FEM with implicit time integration and dense meshing is effective in capturing the spatiotemporal dynamics of anisotropic diffusion processes with localized sources, a phenomenon relevant to thermal analysis, anisotropic materials, and environmental modeling
The Decision Support System for Determining Poor Families Who Receive Blt Uses The Simple Additive Weighting (SAW) Method Case Study: Batubulan Village Perbekel Office
No full textMany government programs have been created to overcome poverty in an area. However, the assistance provided is not on target so it has not reached the hands of the people who really need it. This happened because the determination of prospective poor families to receive BLT was not optimal. Seeing this, the author helped the Head of Social Welfare by creating a Decision Support System for Determining Poor Families Using the Simple Additive Weighting (SAW) Method. Case Study: Batubulan Village Perbekel Office so that it could provide two categories namely poor and not poor. The SAW method was chosen because it can determine the weight value of each criterion and then continue with the ranking process which will select a number of alternatives, in this case families that are categorized as poor families. With this ranking process, correct assessments and accurate results are obtained both in manual calculations and system calculations
Prevalence of Red-Green Color Blindness In High School Students In Malang City
No full textColor blindness is a visual impairment caused by the cone cells of the eye not being able to perceive a certain color spectrum. Color blindness is an X chromosome-linked genetic disorder that has a cross-inheritance pattern (Criss-Cross Inheritance). One type of partial color blindness is red-green color blindness. Red-green color blindness is divided into deutans and protans. The purpose of this study was to determine the prevalence of red-green color blindness in high school students in Malang City. This research was conducted in five high schools in Malang City and total sample was 254 students. The red-green color blindness detection was done using Ishihara's 24 plate book. The analysis was conducted to determine the prevalence of red-green color blindness, allele frequencies of color blindness and patterns of inheritance of color blindness.The results of the study showed that the prevalence of red-green color blindness among students in Malang was 3.54%, with all male patients having a prevalence of 7.89%. Specifically, 1.18% of students were identified as having protan color blindness, while 2.36% had deutan color blindness. The allele frequency for red-green color blindness is 0.0263, while the frequency of the normal allele is 0.9737. Analysis of the pedigree diagram in families with color blindness show proband inherited the color blindness gene from a carrier mother, following a criss-cross inheritance pattern
Analysis of the Time of Dew Occurrence on the DCDB Panel at PLN GIS 150 kV Gunungsari Surabaya
No full textThe DCDB panel is a panel for distributing direct current electricity. Inside the panel there are cables to carry current which affects the temperature of the panel. The greater the current flowing, the greater the resulting temperature. Dew that occurs on the DCDB panel can cause various kinds of electrical disturbances, so the DCDB panel must be kept dry and protected from condensation. The dew parameter is the dew point. In order to minimize the occurrence of dew on the DCDB panel, it is necessary to know the prediction or estimate of the occurrence of dew on the DCDB panel by evaluating the Rectifier room temperature with the external environmental weather temperature. Therefore, research was carried out for 10 days in the PT. PLN (Persero) GIS 150 kV Gunungsari Rectifier room, Surabaya, which contained a DCDB panel. The data obtained is temperature monitoring data in the Rectifier room, DCDB panel body, and DCDB panel door. From this data, observations are made to see the temperature changes that occur in the panel. Environmental weather data is obtained via the Weather Underground website. The research data obtained was analyzed using RMSE and MAPE to check errors and graph plotting using SPSS. Based on the research conducted, it can be concluded that the dew point is estimated to occur at 03.30-05.00 in July with a temperature range of 21.3℃-23.3℃
Tsunami Hazard Evaluation in Temon Sub-district, Kulon Progo Regency Based on the Worst-Case Scenario of the South Java Megathrust Earthquake
No full textKapanewon Temon, the location of New Yogyakarta International Airport (NYIA), is projected to become a new economic center but is vulnerable to tsunami hazards due to its proximity to the southern Java subduction zone. Mitigation efforts are necessary to prepare for the worst-case scenarios. This study assesses tsunami hazard potential based on a worst-case scenario using a geophysical approach through numerical simulations with the COMCOT software. The data used include bathymetry, topography, administrative boundaries, land cover, and fault parameters. Simulation results indicate potential tsunami inundation up to 20 meters in key areas such as Congot Beach, the southern coast of NYIA, and Glagah Beach, with an estimated arrival time of 0.6-0.63 hours. These findings are expected to serve as a reference for spatial planning and disaster risk mitigation efforts in Kapanewon Temon, Kulon Progo Regency
Synthesis of Nanofiltration Membrane with Silica Variation for Waste Water Reduction
No full textRapid industrial development in Indonesia is accompanied by an increase in liquid waste, especially those containing heavy metals such as Lead (Pb), becoming a serious problem for the environment. Based on PermenLHK regulation No. 5 of 2014, TDS and pH levels of industrial waste must meet certain standards. To overcome this, this research aims to develop chitosan-silica-based nanofiltration membranes modified with Polyvinyl Alcohol (PVA) and Polyethylene Glycol (PEG) to efficiently reduce Pb ion content. Chitosan was chosen due to its environmentally friendly nature and adsorption ability, while the addition of silica aims to improve membrane stability. The membrane synthesis method involves sol-gel process with Tetraethyl Orthosilicate (TEOS) precursor, mixing of chitosan, PVA, and PEG, as well as membrane printing and drying. Characterization was performed using FTIR for functional group analysis, BET to measure surface area and porosity, and swelling test to evaluate water absorption capacity. The results showed that the chitosan-silica membrane was successfully formed with a porous structure according to nanofiltration characteristics (pore size 0.0005-0.005 μm). The results showed that in the FTIR test, the 3261-3289 cm-1 region formed a silanol group (Si-OH) so that it could bind to metal ions. In the 1415-1416 cm-1 region is the absorption of C-H. In the 1241-1252 cm-1 region is the absorption of Si-O symmetry of Si-O-Si. FTIR analysis confirmed the presence of silanol (Si-OH) and siloxane (Si-O-Si) groups that play a role in metal ion adsorption. BET tests revealed that the membrane had a specific surface area and micro pores, while swelling tests showed an increase in hydrophilicity with the addition of siloxane
Design of a Thermoelectric Cool Box with Electronic Mobile-Based Temperature Control and Monitoring System
No full textTemperature control in a thermoelectric coolbox is important for maintaining the freshness and quality of stored items. This research aims to design a temperature control and monitoring system for a thermoelectric coolbox based on mobile electronics using the Wemos D1 R32 microcontroller and the Blynk application. The system uses the DHT11 sensor to detect temperature and humidity inside the coolbox. Data from the sensor is transmitted in real-time to the Wemos D1 R32 microcontroller, which then forwards it to the Blynk application via Wi-Fi. Users can monitor temperature, humidity, and control the coolbox's cooling function through the Blynk application on their mobile devices. This system is expected to provide an efficient solution for temperature management and improve user comfort. The test results show that the system can provide accurate and responsive temperature control, with an easy-to-use interface. The research uses 4 peltier elements, which have two different sides: hot and cold. The cold side of the peltier is used for storing mangoes, with a storage temperature between 10-15 oC. The test results show the temperature reached 14oC within 1 hour. In the automatic control system, the fan inside the cabin will turn off when the temperature reaches 14 oC and turn on again when the temperature exceeds 15 oC. Without control, the temperature of the mangoes was recorded at 11.6 oC and kept cooling, while with control, the temperature of the mangoes remained stable at 14.5 oC. This system is effective in maintaining optimal storage conditions
Characteristics and Potential Activity of Aerobic Denitrifying Bacteria from Fish Farming Ponds
No full textThe presence of inorganic nitrogen in the aquaculture environment is inseparable from the nitrogen cycle. The nitrogen cycle always involves microbiological processes, including the activity of microorganisms. Denitrification is one of the main processes to reduce inorganic nitrogen content. This study aims to isolate, characterize, and measure the activity of aerobic denitrifying bacteria in eliminating inorganic nitrogen in waters. Denitrifying bacteria isolated from fish farm pond water samples by enrichment and specific medium. The nitrate reduction activity of denitrifying bacterial isolates was analyzed through the measurement of nitrate, nitrite, and gas levels. Denitrifying bacterial isolates were characterized based on colony morphology, cell shape, and Gram type. Analysis of nitrate reduction rate determined based on Michaelis-Menten kinetics. A total of 7 isolates of aerobic denitrifying bacteria were successfully isolated from enrichment medium with diverse characteristics. The percentage of nitrate reduction activity of the seven denitrifying bacterial isolates ranged from 50.48 - 87.08%. Two selected denitrifying bacterial isolates namely isolates BP8 and BP11 showed the best nitrate reduction activity of 90.14% and 88.45%. Isolates BP8 and BP11 had a maximum speed of nitrate reduction (Vmax) of 0.08 mM/hour and 0.03 mM/hour. The Michaelis-Menten constant (Km) values of isolates BP8 and BP11 were 0.35 mM and 0.44 mM. The denitrifying bacterial isolates obtained have potential as bioremediation agents for inorganic nitrogen compounds in aquaculture