Gravitasi

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

Pingki Pingki — 2024-08-30

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.

Identification of Land Subsidence in Semarang Area Using Gravity Method

Syamsurijal Rasimeng — 2024-08-30

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.

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

Syamsurijal Rasimeng — 2024-08-30

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.

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

Bergita Gella M. Saka — 2024-08-30

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 Calcination Temperature on Characteristics of Hydroxyapatite from Milkfish Bone (Chanos chanos)

Jumiarti Andi Lolo — 2024-08-30

This study investigates the synthesis of bioceramic hydroxyapatite (HAp) from milkfish bone (Chanos chanos) for medical applications. Due to its high bioactive properties and biocompatibility, HAp is becoming a main selection in biomaterials. Milkfish bone, a biological source abundant in calcium, phosphorus, and carbonate, was utilized in this study due to its high potential in the preparation of biocompatible and economical HAp. Applying various calcination temperatures, this study aims to optimize the HAp synthesis process, analyze the effect of temperature on the crystallinity, phase, and particle size of HAp, and evaluate its chemical composition and crystal structure through XRD and FTIR analysis. Results of this research are aimed to provide new solutions in the development of biomaterials from natural resources that are sustainable and biodegradable for medical applications.

Characteristics of ambient seismic noise in Southern Part of Sulawesi from BMKG and GSN network

Wa Ode Awaliah — 2024-08-30

Cross-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.