Gravitasi

ZnO-Ag Synthesis Nanoparticles: Liquid Laser Ablation for Photocatalyst Degradation Of Textile Industrial Waste Dyes

2023-08-31T05:12:50+00:00

The highest absorption optimization occurred in the photocatalyst degradation test under UV light. The highest percentage of photocatalyst degradation was 72.14% in the ZnO/Ag 5 sample. It was adjusted according to the FESEM results for the morphology of the ZnO/Ag nanoparticles and the crystal size on XRD. The synthesis process was carried out using a two-step method in laser ablation in liquid (PLAL). The laser method supports photocatalytic performance to degrade textile dye waste. The lowest percentage of degradation was obtained in the UV-Visible t test of 12.37% as a comparison test, the Dark test was carried out at an interval of 0 and 8 hours and observed using a UV spectrometer. The degradation resistance in the dark is 7.61% on ZnO/Ag at 8 hours.

Identification of Hot Fluid Pathways in Jatimulyo Village, South Lampung Using Magnetic Method

2023-08-31T05:12:50+00:00

Geothermal energy originates from Earth's core heat, creating a hydrothermal system. Surface manifestations, like hot water, hold potential for geo-tourism. Detecting this system underground necessitates a comprehensive study. Geophysical methods, such as magnetics, can be used to predict hot fluid pathways and identify structural and alteration zones. This study aims to use the magnetic method to locate the outflow pathway in the Jatimulyo village, Jati Agung sub-district, South Lampung. Results reveal an anomaly in the form of a fault structure acting as a pathway for hot water. The distant hot spring lacks pluton granite and exhibits lower temperatures. The findings suggest a low magnetic anomaly along the outflow path, attributed to the loss of magnetic properties in heated rocks. Geological data indicates a northwest-southeast fault in the western part of the area, which may influence the fluid pathway.

Identification of the distribution of golf mineral carrier rocks using the geomagnetic method in Pujut Lombok

2023-08-31T05:12:51+00:00

Lombok Island is one of Indonesia's regions that has high gold potential. The purpose of this study was to determine the distribution and potential of rocks containing gold in Pujut, Central Lombok. The method used is geomagnetic. The results showed that the moderate geomagnetic anomaly was the response of the gold mineral host rock scattered in the center of the study area. The 2D inversion model shows that the rock layers in the study area consist of sandstone, claystone, tuff, tuff breccia, basalt, cracks, intrusions, and faults. This type of rock is thought to be a carrier of gold minerals, except for clay, basalt and breccia. The depth of the gold-bearing rock layer is 0 m to 230 m from the ground surface, with a volume of 1.22x109 m3 in an area of 12 km2. In the future it is necessary to drill and analyze the gold content.

Surface Rupture Hazard of Palu-Koro Fault in Palu City

2023-08-31T05:12:51+00:00

The Palu-Koro fault surface rupture, the latest active fault trace, provides valuable geological evidence and a chance to study its geometry, including strike length and damage zone width. Direct measurements indicate a primary north-northwest orientation, ranging from N314oE to N357oE, with a slip value of 2.3 – 5 m. The central part of Palu City experienced the most significant displacement. The surface rupture damage effect on the active Palu City fault spans 11 to 56 m, perpendicular to the fault line, causing substantial damage to buildings, shifting foundations, and altering roads. Liquefaction effects like sand boils, cracks, and stagnant water occurred. No buildings or infrastructure in the damaged zone remain in good condition, categorizing the area as a high-hazard zone. Based on geotechnical engineering and building structure assessments, continuing to construct buildings along the fault path is strongly discouraged.

Effect of Calcination Temperature Variation on Hydroxyapatite of Cuttlefish Shell Waste (Sepia Sp.)

2023-08-31T05:12:51+00:00

This study aims to determine the effect of calcination temperature variations on hydroxyapatite from cuttlefish shell waste. Extraction of calcium carbonate (CaCO3) into calcium oxide (CaO) using the calcination method with temperature variations 600C, 800C, and 1000C for 5 hours. The results showed that calcination temperature affects the synthesis of hydroxyapatite compounds. Based on FTIR characterization, the optimum calcination temperature is at 1000°C. Based on SEM analysis result, hydroxyapatite particles from cuttlefish shells appear homogeneous with an average particle diameter of 0.57 µm. EDX result shows that Ca/P ratio of hydroxyapatite from cuttlefish shell waste is 2.08. It can be concluded that the cuttlefish shell waste in this study can be used for biomedical applications, such us a bone implant material because it has a Ca/P ratio of more than 1 so it is not easily dissolved and can be accepted by the body.

Characteristics of Rock Layers as Aquifers in Tamalanrea Region

2023-08-31T05:12:51+00:00

Groundwater can be used as a form of fulfilling needs, such as making wells for shallow groundwater (surface water) and deep groundwater (aquifers). This study aims to determine the subsurface resistivity of the study area by calculating and modeling the results of geoelectrical measurements as well as information on the groundwater-bearing rock layers. Geoelectric measurements use the "Schlumberger" method then the data is processed by the "Res2DinV" program. Measurement points were in 3 places in the Tamanalrea area of Makassar City. The results found 6 subsurface layers, namely soil layers, tuff as shallow aquifers (freshwater), tuff as shallow aquifers (brackish), tuff as shallow aquifers (freshwater), hard volcanic breccias (massive), tuff as aquifers (freshwater) with prospects for exploited. The lithology is dominated by volcanic rocks consisting of water-saturated tuff rocks characterized by low resistivity values and volcanic breccia rocks have undergone weathering and massive conditions with high resistivity values.