Measurement of the Sound Absorption Coefficient of Rice Straw (Oryza Sativa) Acoustic Material as Noise Dampener

This study determines the sound absorption coefficient values of rice straw acoustic material as a noise reducer using the two-microphone impedance tube method based on ISO 10534-2:1998 standards. Two test variables were employed in this research. Composition variation consisting of three samples and thickness variation also comprising three samples. Composition variation was conducted to evaluate the ability of rice straw as a sound absorber, while thickness variation was used to determine the effect of thickness on the sound absorption coefficient of rice straw acoustic material. All test samples obtained the highest absorption coefficient values at a frequency of 1600 Hz. The acoustic material in the composition variation achieved the highest absorption coefficient values of 0.30, 0.34, and 0.37, respectively. The thickness variation obtained the highest absorption coefficient values of 0.73, 0.79, and 0.95, respectively. The obtained sound absorption coefficient values meet the standards established by the International Standardization Organization 11654

Identification of Chemical Element Using X-Ray Fluorescence in Soil with Landslide Potential from Sandabilik Village, Tana Toraja

Landslides 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

Effect of Filter and Thickness Variation on Entrance Skin Exposure (ESE) Values of Thorax Organs

the 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

The Subsurface Rock Modeling with Half Slope Inversion of Reduce to the Pole Geomagnetic Anomaly in Hot Spring Natar-Lampung Area

The research in South Lampung's Natar area assesses geothermal heat source potential using the magnetic method with 89 measurement points along the Lampung-Panjang Fault line in a 3 km^2 area. Reduce To The Pole filtering enhances magnetic data accuracy. The Peter Half Slope method is employed, revealing depth ranges for different underground indicators (82.63 m to 144.25 m for very thin bodies, 61.97 m to 108.19 m for intermediate bodies, and 49.57 m to 86.55 m for very thick bodies). Geological analysis of the Lampung-Panjang fault area correlates with the Tanjungkarang Sheet Map, indicating various rock types within the Lampung Formation. The study underscores the Peter Half Slope method's effectiveness in determining subsurface anomaly depth through magnetic data

Subsurface Utility Mapping on SYT Road Segment, Yogyakarta Using Ground Penetrating Radar (GPR) Frequency 500 Mhz

This research was carried out aimed to detect the presence of subsurface utilities and map the utilities contained in the SYT road segment, Yogyakarta. This aims to prevent damage and leakage when planting new utilities in the future. Ground Penetrating Radar (GPR) method with a frequency of 500 MHz measure in 12 lines, processed using ReflexW. The result shows the utilities consist of cable and pipe utilities. The wires will provide a nested hyperbolic anomaly response, while the pipe provides a single hyperbole anomaly. The continuity anomaly is suspected as a utility network. The continuity is seen based on the depth and dimensions of the hyperbola are similar. The utilities contained in the SYT road segment; Yogyakarta are at a depth of 0.5 m - 2.8 m. Where there is continuity which is suspected as a cable and pipe network

Subsurface Profile Mapping for Infrastructure Foundation Laying

Proper evaluation of soil layers is crucial to prevent potential construction issues. The selection of the layer for the foundation of a construction project impacts the loading, stability, and fundamental behaviour of the structure. In this study, we will map the geological structure and lithology of the subsurface layers of the earth to identify a suitable location for the foundation of infrastructure. The resistivity geoelectric method was utilized for predicting structural conditions beneath the soil's surface layer by measuring a material's specific resistance. The obtained results were refined by conducting geological and geophysical analysis. The study site's resistivity values ranged from 16.8 Ωm to 584 Ωm and were interpreted as layers of mud, sand, and gravel. The investigation determined that the suitable layers for foundation construction consist of sand and gravel situated beyond a depth of 37.06 meters beneath the surface

The Identification of Aquifer Layers Using Geoelectric Resistivity Method in Jono Oge Village, Sigi Biromaru District, Sigi District

Research has been carried out in Jono Oge Village to find out the distribution of aquifer layers after liquefaction caused by the earthquake on 28 September 2018. This research uses Automatic Array Scanning method with a total of 5 passes. Data collection was carried out on 5 tracks, with a total length of each measurement track of 240 meters. The results obtained show that the aquifer layer has a specific resistance value of 59.70 - 149.24 Ωm with a formation factor value of 2 - 5. It is thought to be an aquifer layer consisting of sand and gravel. This layer is at a depth of ± 18 – 39 m below the ground surface with a thickness of around ± 10 – 20 m, so this aquifer layer is thought to have experienced a decrease or change in depth of around ± 10 m after the liquefaction disaster

The Influence of Eco Enzyme on The Reduction of Electromagnetic Radiation from Mobile Phone

Radiation 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

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

PT. 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

Identification of Land Subsidence in Semarang Area Using Gravity Method

Gravity 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