Gravitasi
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Pertamax Quantity Optimization by Controlling Losses Using Vapor Recovery Unit at Fuel Terminal Bandung
Full text linkThis research was conducted at the fuel terminal, a storage and distribution facility for Pertamax fuel, with the aim of addressing Pertamax losses due to evaporation in fixed roof tanks. This evaporation leads to the emission of hydrocarbon vapors, which have a negative impact on the environment. One proposed solution was the use of a Vapor Recovery Unit (VRU), which can capture up to 95% of hydrocarbon vapors and convert them back into liquid form. This study employed the calculation methods of breathing loss and working loss to analyze the efficiency of the VRU in controlling losses. The research findings shows that the VRU was effective in reducing emissions and controlling losses, making the implementation of VRU a recommended strategic step to enhance operational efficiency and reduce environmental impact at the fuel terminal. This research is expected to serve for further studies on optimization of VRU usage in the fiel
Identification of Chemical Element Using X-Ray Fluorescence in Soil with Landslide Potential from Sandabilik Village, Tana Toraja
Full text linkLandslides occur frequently in the South Makale sub-district. The disaster resulted in material losses and casualties. Landslides can occur due to a variety of factors. One of these is unstable soil conditions caused by the soil's physical properties, specifically weak soil cohesion (binding capacity) or rocks. This study aims to identify the mineral properties of soil in potential landslide areas in Sandabilik Village, Tana Toraja. This sample was tested using X-ray fluorescence (XRF). The soil samples collected at the landslide site were 50 cm and 100 cm deep. Sample test results show that the content of soil chemical compounds in Sandabilik Village, South Makale District, Tana Toraja Regency, is dominated by SiO2 (Silica Oxide), both at a depth of 50 meters (72.02%) and at a depth of 100 meters (56.55%), respectively. Fe2O3 compounds were 15.65% at a depth of 50 meters, and 24.50% at a depth of 100 meters
Identification of Land Subsidence in Semarang Area Using Gravity Method
Full text linkGravity data processed with Surfer software and Microsoft Excel using gravity corrections, spectrum analysis, and separation of residual and regional anomalies, can then be identified which areas are vulnerable to surface deformation such as Semarang City. The results obtained several areas that have the threat of deformation and disasters due to geology, namely in the northeast and southwest of the Semarang area marked by negative green to blue anomalies including Gajah Mungkur, Tugu Muda, Tanah Mas, and Gayamsari areas have negative anomalies, so they are identified as areas with thick sedimentary layers which are one of the causes of surface deformation. In the southeast to northwest of Semarang, Candi Sari, Simpang Lima, Tugu Mas, and Tanjung Mas, marked by yellow to reddish colors, are areas that have positive anomalies, so they are identified as areas that are quite safe in terms of deformation characterized by thin sediment layers
Effect of Magnetic Field on Germination of Purple Eggplant (Solanum melongena L) using Helmholtz Coils
Full text linkResearch has been carried out on the effect of magnetic field on the germination of purple eggplant (Solanus Melongena L) using Helmholtz coil. This research aims to determine the effect of exposure to a magnetic field and exposure time on the germination of purple eggplant. This study used 100 samples of purple eggplant seeds, of which 10 samples were controls (0 mT) and 90 samples were exposed to a magnetic field 0,3 mT, 0,4 mT and 0,5 mT which was divided into three exposure treatments, namely 15 minutes/day, 25 minutes/day and 35 minutes/day for 7 days. Based on the data obtained, it is proven that the strength of the magnetic field and the long exposure time have an effect on the growth and increase in the length of purple eggplant seed sprouts. The optimum magnetic field strength and exposure time is 0.4 mT and exposure time is 25 minutes/day. 
Analysis of Lead Content in Cereal-Based Foods Using Atomic Absorption Spectrometer (AAS)
Full text linkCereals-based foods are foods with the highest level of consumers because they have high levels of carbohydrates. Food is also the largest contributor to heavy metal contamination that enters the human body, especially heavy metal Pb reaching 90%. Pb heavy metals with too high levels in humans can damage human organs and cause death. Research related to the analysis of heavy metal content in cereal foods, especially vermicelli has been carried out. The analysis method uses GFAAAS (Graphite Furnace Analysis Atomic Absorption Spectrometer). Some solution that must be prepared include vermicelli sample solution, working standards, and aquadem as a diluent. Based on BPOM regulation No. 5 of 2018 states that lead content in vermicelli must be less than 0.25 mg/Kg. Results indicate that First sample has an ineligible status, but second and third samples are qualified because they are negative at the time of rough determination heavy metal lead (Pb)
The Influence of Eco Enzyme on The Reduction of Electromagnetic Radiation from Mobile Phone
Full text linkRadiation generated by mobile phones can potentially cause health problems to users. This study aims to limit or suppress the effects of electromagnetic wave radiation using multifunctional fluids, namely eco enzymes. There are 2 treatments, namely using eco enzymes measuring 600 ml and 1.2 L with 6 passes with a certain distance and a duration of 0 minutes, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, and 30 minutes. The results of data analysis were carried out using the effectiveness equation. The highest average values of the electric field and magnetic field were found on path A before using the eco enzyme, with measurements of 6 V/m and 0.18 μT. Eco enzyme successfully reduced electromagnetic radiation from mobile phones with an effectiveness of 53%. Therefore, eco enzyme is very useful as an environmentally friendly material that can protect us from exposure to electromagnetic radiation
Characteristics of ambient seismic noise in Southern Part of Sulawesi from BMKG and GSN network
Full text linkCross-correlations between stations for ambient seismic noise derived from 1 year of uninterrupted data in southern part of Sulawesi has been conducted. The main purpose of this study is to investigate the characteristics of ambient seismic noise and to determine the reliable period band for surface wave tomography. We apply ambient noise analysis to vertical-component broadband data recorded by 11 stations deployed by BMKG and GSN network. Our results show that the ambient noise is dominantly coming from Flores Sea and Makassar Strait. The SNR > 5 is found at period between 8–30 s for most of interstation distance. The seasonal variation has not given significant impact, but strong ambient noise emerges when using recordings that are stack of 1 year in duration with data selection. We propose that the good period band EGF for surface wave tomography in southern part of Sulawesi is at period band 8-30 s
Acoustic Material Capability of Pineapple (Ananas comosus) Leaf Fibre with PVA (Polyvinyl Alcohol) Adhesive as Noise Absorbent
Full text linkNoise is noise pollution that can disturb health if its intensity exceeds the hearing threshold. Acoustic material is one way to control noise. This research uses pineapple (Ananas comosus) leaf fibre as an acoustic material with Polyvinyl Alcohol (PVA) adhesive. The purpose of this research is to measure the value of the sound absorption coefficient using the impedance tube method with variations in composition and thickness. The results showed that for variations in the composition of pineapple leaf fibre with PVA (7:3, 3:1, 8:2, and 6.5 :3.5) at a frequency of 800 Hz, the sound absorption coefficient values were 0.18; 0.17; 0.37 and 0.18, respectively. In the thickness variation (1 cm, 1.5 cm, and 2 cm), the sound absorption coefficient values were 0.47; 0.65 and 0.73, respectively. The results show that the amount of sound absorption in the composition variation and thickness variation has met the ISO 11654 standard
Application of the LEM-Bishop Based on the Generalized Hoek-Brown Criteria for Assessing the Stability of Rock Slopes at Mining Area of PT. Karya Sopai Sejahtera, Palu City
Full text linkPT. Karya Sopai Sejahtera (PT. KSS) operates in rock mining using an open-pit system in Watusampu, Palu, Central Sulawesi. Excavation alters slope geometry, affecting stability and risking landslides, impacting safety, equipment, and productivity. To address this, a geotechnical study assesses slope stability using the Limit Equilibrium Method (LEM) - Bishop method. Geological surveys and Electrical Resistivity Tomography (ERT) reveal predominantly andesite rock with fresh gray and weathered brown colors, hypocrystalline and equigranular textures, and quartz, pyroxene, biotite, and hornblende minerals. The slope design includes a 150-meter overall height, bench heights of 15-25 meters, widths of 3-5 meters, a single slope angle of 70°, and an overall angle of 61°. Static analysis shows stability (FS 1.94), but dynamic conditions, including earthquakes, reduce FS to 0.43, causing instability (FS < 1.1) with a 100% failure probability. The slope is stable except during strong earthquakes
Effect of Filter and Thickness Variation on Entrance Skin Exposure (ESE) Values of Thorax Organs
Full text linkthe aim of this research are to knowing the effect of using variations and thickness of Al, Cu and Pb filters on ESE values using thorax examination phantoms and to determine the effect of variations in irradiation time-current on the use of variations and thickness of Al, Cu and Pb filters on ESE values using thorax examination phantoms. The results showed that the thicker the filter used, the ESE value obtained decreased, and vice versa. While the results obtained for the irradiation time-current are the greater the time-current used, the ESE value obtained increases, and vice versa. Filters that enter the tolerance limit of thorax examination are Aluminum (Al) filters with a thickness of 1.5 mm and a time-current of 8 mAs, which is 0.089594 mGy. This is influenced by several factors including the thickness of the filter used, the irradiation time-current performed and the density of the filter