Acoustic Material Capability of Pineapple (Ananas comosus) Leaf Fibre with PVA (Polyvinyl Alcohol) Adhesive as Noise Absorbent

Noise 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

Effect of Magnetic Field on Germination of Purple Eggplant (Solanum melongena L) using Helmholtz Coils

Research 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.&nbsp

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

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

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

Pertamax Quantity Optimization by Controlling Losses Using Vapor Recovery Unit at Fuel Terminal Bandung

This 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

Evaluating the Stability of Red Dragon Fruit (Hylocereus polyrhizus) as Natural Dyes: Impact of Concentration, pH and Storage Duration

This reseach explores the application of Hylocereus polyrhizus extracts as natural dyes, emphasizing anthocyanin content, stability, and light absorption under varying conditions. The findings indicate that undiluted extracts attain maximum light absorption in the 520-550 nm spectrum, aligning with the anthocyanin pigments that impart the fruit's vivid color. Increased dilution results in diminished absorbance, attributable to reduced anthocyanin levels. The research highlights the importance of pH on pigment stability, with optimal absorption at pH 3-4, while elevated pH leads to decreased absorption due to anthocyanin structural alterations. Notably, a rise in absorbance on Day 15 of a 15-day storage period may indicate pigment stabilization, potentially through copigmentation with phenolic compounds. Nonetheless, a general decline in total anthocyanin content across samples is noted, likely influenced by environmental conditions and extraction inefficiencies. This investigation underscores the potential of red dragon fruit extracts as viable, sustainable dye sources for DSSCs and other applications

Analysis of Lead Content in Cereal-Based Foods Using Atomic Absorption Spectrometer (AAS)

Cereals-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)

Characteristics of Rock Layers as Aquifers in Tamalanrea Region

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

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

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

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. &nbsp