Analisis Kondisi Atmosfer Saat Kejadian Hujan Lebat dan Angin Kencang di Probolinggo Berdasarkan Citra Satelit dan Citra Radar

The phenomenon of extreme weather, heavy rain and strong winds hit four sub-districts in Probolinggo Regency, East Java on January 3, 2020 at 17.00 WIB. Based on data from the East Java Regional Disaster Management Agency (BPBD), the incidence of heavy rain and strong winds resulted in damage to as many as 204 houses. This study uses remote sensing data in the form of C-Band Radar and Himawari-8 Satellite and Copernicus ECMWF renalysis data. The data is processed into spatial maps and graphs which are then analyzed descriptively. The results of data analysis show that the reflectivity value reaches 43 dBZ and the wind speed reaches 13.57 m / s with a rainfall of 15.83 mm / hour at 10.00 WIB. Based on the analysis of the Himawari-8 Satellite, the peak temperature of the clouds reached -73.1 oC and the atmospheric lability data showed that the atmosphere was unstable, which could indicate the possibility of heavy rain and strong winds. The value of vortices in the 1000 mb - 500 mb layer is negative and the humidity value ranges from 85% - 90% and a positive sea surface temperature anomaly value and the presence of windshields result in convergence of air masses which can support convective cloud growth as the cause of heavy rain events and strong winds in Probolinggo Regency, East Java

Microzonation of Cisarua District Using Horizontal Vertical Spectral Ratio

The Bandung region is part of the framework of the Indonesian tectonic system, namely the tectonic plate meeting zone, where the Indo Autralia plate is infiltrated under the Eurasian plate in a convergent manner. The subduction process produces an effect in the form of an active fault geological structure in the Bandung area. One of these active faults is the Lembang Fault, which has a length of ± 29 kilometers and a shear acceleration of 3 to 5.5 millimeters per year. The microtremor measurement method is a passive geophysical method that utilizes natural subsurface vibrations so that it can provide dominant frequency data and amplification factors for soil layers. Based on the results of seismic susceptibility research using microtremor measurements using the HVSR method in the Lembang Fault zone in Cisarua Sub-District, it can be seen that the distribution of the dominant frequency values tends to be influenced by lithology and topography. In the research area, it is known to have a dominant frequency value that varies due to the different types of lithological units. In general, the dominant frequency ranges from 1-3 Hz because it is dominated by tuff sand and tuff pumice, and areas composed of volcanic breccias have a dominant frequency value between 3-6 Hz. Meanwhile, the amplification factor value will be influenced by rock deformation and weathering. The area that has a very high amplification factor value is in the southeast of the study area with an A0 value greater than 5. This indicates that the area is composed of a layer of thick and not dense tuff sand

Pemetaan Tingkat Kerawananan Banjir Di Kota Jambi Menggunakan Metode Scoring Dan Overlay Berbasis Sistem Informasi Geografis

This research is about flood vulnerability mapping in Jambi City based on Geographic Information System (GIS). This study is aiming to find out the flood vulnerability level, spatial distribution of flood, and flood prone areas in Jambi City. We used five parameters that affect flood vulnerability, including land slope, land level, land use, soil type, and rainfall during 2019. The method used is the scoring and overlay method with the help of ArcGis software. Flood vulnerability level was divided into three categories, namely quite vulnerable, vulnerable, and very vulnerable. The results obtained in this study are that most of Jambi City has a level of flood vulnerability in the vulnerable category, which is an area of 9254.82 ha (58%), while for the area that is dominated quite safe from flooding, Jambi Selatan sub-district, is 2849.14 ha (18%). This shows that more than half of the Jambi city area is a flood-prone area so it is very important to carry out structural and non-structural mitigation actions

Analisis Proksimat Karbon Kulit Kemiri (Aleurites moluccana) dengan Variasi Suhu Karbonisasi

Candlenut (Aleurites moluccana) is a plant with various benefits. Currently, candlenut is mostly used as a spice, candlenut shells also has a high calorific value so that it can be used as fuel. Candlenut has shells which is an organic waste. Candlenut shells have a hard texture and high carbon content. Most of the candlenut shell is used as fuel and only a small part is used as raw material for carbon production. Candlenut shell have good physical and chemical properties as carbon raw materials. Activated carbon is one of the carbon phases that can be used for various applications. In this paper, we report on the synthesis and characterization of carbon from candlenut shells to obtain high-quality carbon by controlling the carbonization temperature. In carbon production, we use variations in carbonization temperatures of 300, 400, 500, 600 and 700 C. Proximate analysis was carried out to determine the moisture content, ash content, volatile matter content and bound carbon content. Analysis of the effect of carbonization temperature on the quality of carbon from candlenut shells resulted in the highest carbon in the sample with a temperature of 700 C, producing carbon with 5.32% moisture content, 9.40% ash content, 12.76% volatile matter content, and fix carbon content 72,52%

Synoptic and Mesoscale Analysis of Extreme Rainfall Event in Cilacap Meteorological Station, Indonesia on December 7, 2018

The highest rainfall for the last five years (2016-2020) was recorded at 199.5 mm in twenty-four hours at the Cilacap Meteorological Station. This study examines the dynamics of the atmosphere with a focus on the synoptic scale and the meso scale. This is done because high rainfall with a long duration is usually caused by a wider scale atmospheric circulation than just local convection scale. The rush of cold air masses from the Asian highlands that propagates across the equator is the main cause on the synoptic scale. In addition, the air flow from the south meets the air mass flow from the north right on the island of Java. On the meso scale, numerical simulations have not been able to properly estimate rainfall with values that tend to be underestimated. However, the value of convective available potential energy is high enough to support the growth of convective clouds. Based on himawari-8 satellite imagery, it is clearly observed that the clouds formed due to atmospheric dynamics are meso-scale convective cloud systems with a life span of more than six hours. The cloud growth is quite massive, which is indicated by the cloud top temperature value being lower than -80C in the mature phase. Thus, the resulting rainfall is quite heavy, causing flooding in parts of Cilacap

Physical and Thermal Properties of Briquettes from Empty Fruit Bunches and Palm Kernel Shell by Mixing Tapioca Flour and Molasses

West Java has the potential of palm oil wastes such as empty fruit bunches (EFB) and palm kernel shell (PKS) that can be used for fabrication of briquettes as raw materials. Briquette as a solid fuel and as a substitute for fossil fuel must have a good quality to be accepted in the market, such as having a good thermal and good physical properties. This research, reviewing the effect of particle size parameter and the effect of adding adhesive on briquette to heating value, thermal properties and physical properties. Briquettes were determined by using varying EFB and PKS biomass ratios of 50:50 and by adding 7% adhesive from tapioca flour or molasses of the total mass of the briquette. Particle size variations are set for 20 mesh and 40 mesh. The best heating value was found at 5,898 cal/g in the sample briquette by using 40 mesh particle and tapioca flour adhesive. The thermal properties test shown the combustion rate of 0.34 g/minutes and combustion lenght of 111 minutes found in 40 mesh briquette sample by using tapioca flour adhesive. The physical properties test shown the best density value of 0.215 g/cm3 and shattering resistance of 66,23% found in the 40 mesh briquette sample by using tapioca flour adhesive. The best durable value found in sample briquette with 20 mesh particle with tapioca flour adhesive which is 54.35%. The result was indicated that briquette with 40 mesh particle size and tapioca flour adhesive gives the best result of heating value, thermal properties and physical properties

Karakterisasi Sifat Fisis dan Mikrostruktur Papan Gipsum dengan Variasi Komposisi Lateks

Gypsum board is one of the advanced products of gypsum material with a mixture of fiber/fiber or other materials. Gypsum board has a weakness in its physical properties that easily absorb water. Therefore, there is a need for innovation in the manufacture of gypsum boards that will produce even better quality. The manufacture of gypsum board can utilize waste materials such as coconut shells and rice husks and latex as adhesives. The mixture of gypsum board materials including: gypsum, coconut shell, and rice husk used was 70%, 15%, 15% with latex variation 10%, 12%, 14%, 16%, 18% with FAS 0.5 and drying for 28 days. The parameters of the physical properties test include: density and thickness expansion, as well as microstructural testing to determine the morphology of the gypsum board sample. Analysis of the physical properties of gypsum board obtained optimal results, namely in sample A with a variation of 10% latex composition, the density value was 1.35 g/cm3, and the thickness expansion was 5.03% which met the SNI Standard 01-4449-2006. While the microstructure produces morphological images that show inhomogeneous distribution, particle agglomeration forms, and impurities

Kinerja Metode Elektroflotasi pada Pengolahan Air Limbah Pewarna Tekstil Dispersi

Disposal of textile wastewater above the maximum quality standard into the environment will cause many negative impacts on the ecosystem in the environment. The textile industry utilizes about 2/3 of the total dye products. About 10-15% of the use of these dyes is wasted as waste water. Dispersion dyes are a type of synthetic dye that is relatively widely used in the textile industry. Disperse dyes are insoluble in water and have relatively high chemical resistance. One of the suitable methods applied to treat textile dye dispersion wastewater is electroflotation. Electroflotation works on the basic principle of an electrolytic cell. The performance of electroflotation is influenced by several factors, including the difference in electric potential and the length of time for electroflotation. The purpose of this study was to study the effect of electric potential difference and processing time on the performance of the electroflotation method in textile dye dispersion wastewater treatment. In this study, the electroflotation performance was measured based on the ability of the method to reduce the COD (Chemical Oxygen Demand) value and the color level of the treated textile wastewater. In addition, the specific electrical energy requirements and the value of the decrease in dye concentration per unit of electrical energy are also calculated. The results showed that the optimum conditions for electroflotation were achieved by using an electric potential difference of 12 V and an electroflotation time of 60 minutes. Under these conditions, the COD value and color level of textile wastewater can be reduced with separation efficiency of 88.9% and 93.3%, respectively, with a specific electrical energy requirement of 200 kWh/m3. Meanwhile, the decreasing value of dye concentration per kWh of electrical energy based on COD value and color level were 16293.3 ppm/kWh and 23333.3 Pt-Co/kWh, respectively

Kajian Pengaruh Temperatur Sintering terhadap Peningkatan Derajat Kristalinitas Karbon dari Limbah Kulit Kemiri

Allotropes of carbon has advantages in the ability to intercalate ions, atoms or molecules that potentially to apply in various technological applications. Graphite one of allotrope carbon which has well intercalation and ion transport capabilities. In case, the synthesis of activated carbon made from candlenut shell was carried out with carbonization temperatures at 700C and used a chemical activator in form of 30% KOH. After the activation process, given the sintering treatment for activating carbon with temperature of 950C and 1000C, respectively, which this process is expected to increase the crystalline phase of activated carbon close to the graphite phase. The result showed that dominantion of the structures were amorphous, with varying degrees of crystallinity ranging 35.23% and 35.44%, respectively, and the degrees of graphitization 36% and 37% for the vertical and horizontal directions, respectively. The treatment of the sintering process with a temperature of 1000C has the highest degree of crystallinity, 35.44%. This indicates that the sintering process has an effect on the activated carbon

Karakterisasi Reservoir Karbonat Berdasarkan Analisis Inversi Seismik Impedansi Akustik dan Atribut Seismik di Lapangan “CLM” Cekungan Jawa Barat Utara

Research with 2D seismic data and wells used for acoustic impedance (AI) seismic inversion analysis and seismic attribute analysis has been carried out in the "CLM" Field of the North West Java Basin. The purpose of this study is to obtain the distribution pattern of acoustic impedance in the carbonate reservoir and to determine the hydrocarbon prospect zone in the study area. The acoustic impedance distribution pattern is obtained by the AI inversion process carried out on 15 2D post-stack seismic lines and 2 wells. Meanwhile, the identification of hydrocarbon prospect zones is carried out by integrating 3 maps, namely acoustic impedance slice maps, RMS amplitude attribute slice maps and envelope attribute slice maps. Based on the results of the acoustic impedance seismic inversion, it was found that the target reservoir zone in the Upper Cibulakan Formation was carbonate that had high AI values with a range of 42500-52500 (ft/s)(g/cc). Sandstone has a moderate AI value with a range of 34000-42500 (ft/s)(g/cc) and shale has a low AI value with a range of 21000-34000 (ft/s)(g/cc) which has the potential to become a seal rock. Meanwhile, based on the results of the analysis of seismic attributes, the hydrocarbon prospect zone is located in the northeast and northwest of the ITSNU-2 well location in the "CLM" field in the research area