bluuebunny/crossref_metadata_2025_split huggingface dataset:
Groundwater level in the southern part of surakarta city depicted from vertical electrical sounding
Authors: Koesuma Sorja , Sunaryo  , Sutarno Doddy , Handono Ramelan Ari 
Published: March 2021

Abstract
In the last two decades, the city of Surakarta has shown significant population development, as well as in industry and tourism. This development must be accompanied by the provision of water resources for the lives of the population. As we know that in 2015 and 2019, there was a long dry season that resulted in a lack of water for residents and for the hotel industry, where most residents of Surakarta and the hotel industry are located in the southern part of the city of Surakarta. Therefore, the purpose of this study was to determine the level of groundwater aquifers in the south part of the city of Surakarta. We used the vertical electrical sounding (VES) method with the Schlumberger configuration at 10 survey locations. The current electrode interval in the Schlumberger configuration is from 1.5 meters up to 300 meters. With this stretch of electrode current, it is expected to reach target depth of up to 150 meters. Data processing uses the principle of non-linear optimization method which is to minimize errors from measurement data and models. We found that the depth of the groundwater aquifer was at 40 meters at S9 (shallowest), and at 80 meters at S5 (deepest). Then we compared this result with the survey in 2010 in the same location and same method. We found the lowering of the water table in some site surveys around 3 to 10 meters.
Analysis of Sea level Rise by Using Satellite Altimetry Data of West Sumatra Waters in 2009 – 2019
Authors: Vina Chrismiantari Riza , Koesuma Sorja , Legowo Budi 
Published: March 2021

Abstract
The West Sumatra Waters is one of the vulnerable area exposed to impact of Sea Level Rise where the West Sumatra Waters located adjacent to the Indian Ocean Waters and Andaman Sea. Some of the negative impact caused by SLR are coastal abrasion, erosion, and sinking of small islands also increases risk of flooding. Therefore, research about SLR must be continued as an information in management of coastal areas. The technology that is widely used in observing SLR is the satellite altimetry. The data used in this research are Jason 2 and Jason 3 satellite altimetry data from NOAA since 2009 until 2019 and the tidal data of the IOC as a comparator. The research uses linear regression method to get the sea level rise value. From the research results obtained SLR value in the West Sumatera Waters is -2.5 mm/years. The decline of the sea level in the region is caused by many factors such as the Indian Ocean Dipole and ENSO phenomenon.
Very low frequency - electromagnetic (vlf-em) for detecting groundwater river patterns in karst area of kaligambir village
Authors: Iswahyudi A , Prabawa SE , Warnana DD , Widodo A 
Published: March 2021

Abstract
Groundwater flow in the limestone areas through gaps, fractures, and dissolving channels whose dimensions and directions are erratic. If the dimensions and direction of the river flow are known, it will be easier to exploit water to meet the needs of the community. The dimensions and direction of the underground river flow can be mapped using the VLF-EM method. VLF-EM measurements were carried out on 18 trajectories spread across two study areas. Each VLF-EM track has a length of 200 meters, taking data at intervals of 2 meters. Processing of VLF-EM data on each path produces a distribution of resistivity values along the measurement path. Resistivity values around Bleri Cave range between 53 Ωm - 685 Ωm, underground river flow is located at a depth of ± 40 meters and the direction of flow is from northeast to southwest. The distribution of underground river flow around the Bleri Cave with resistivity values around the Lowo Cave ranges from 61 Ωm - 550 Ωm, in the area around the Lowo cave there are no underground anomaly caves that are not drained by water. If you want to exploit underground river water it should be done in the area around Bleri Cave.
Mitigation Strategic of Drought in Central Java Indonesia during Covid-19 Pandemic
Authors: Koesuma Sorja , Azzahra Kusuma Delfina , Widya Harmoko Iis 
Published: March 2021

Abstract
In 2019, most of the areas in Central Java Indonesia experienced drought disaster. There are 3 districts that conduct emergency response due to drought disasters. If there is another drought in this year during Covid-19 pandemic, it will be very fatal due to the need for more water than usual. Besides being used for daily needs, water is also needed for washing hands and bathing during the Covid-19 pandemic. This study aims to determine the level of drought in Central Java province and provide solutions on how to reduce the drought strategy so as not to aggravate the spread of Covid-19. The method used to determine rainfall prediction is the Canonical Correlation Analysis (CCA) method with input data of average monthly rainfall for approximately 30 years in Central Java. Then to determine the drought map using the Standardized Precipitation Index (SPI) method with input data of rainfall prediction for the last 3 months from the CCA method. The results of data processing show that in August to October 2020 there was a drought with normal levels in almost all regions in central Java, except in the Muria peninsula which is still very wet (August-September) and wet (October). In November and December 2020 there was a drought in all regions in Central Java with normal levels. The level of dryness in this period is normal, meaning it is neither too high nor too dry. Meanwhile, based on several references that at the end of the year there will be a La Nina phenomenon, so that at the end of the year there will be no drought but there will be lots of rain. Several recommendations to overcome this situation will be presented in the final section of this paper.
Microzonation Efforts of Disaster Mitigation using Mikrotremor Refraction Method (ReMi) in Kuwu, Grobogan
Authors: Legowo Budi , Harjana  , Wildan Rantanaka Kidura 
Published: March 2021

Abstract
Microtremor refraction is one application of geophysical methods for disaster mitigation microzonation in a region based on dominant frequency value and amplification value. The purpose of this study is to determine microzonation of soil vulnerability index (Kg
) from the result of the dominant frequency value (f0
) and amplification (A0
). This research has been done in the Kuwu of Grobogan District using P.A.S.I Seismograph Mod. 16S24-P and 3D Borehole Geophone Model GFA 60/100. Measurements at each point for 20 minutes and performed for 2 repetitions. The interval of each measurement point is about 350-400 m with a total of 12 points of measurement. Microtremor data processing using Geopsy and Surfer 11 software to create microzonation maps. The result of the dominant frequency value is between 2.14 Hz to 10.26 Hz with an amplification value between 1.47 to 2.40. The value of soil vulnerability index is between 0.23 to 2.20. The location with the highest soil vulnerability index value is at location 5 with a soil vulnerability index value of 2.20.
Development of air temperature and soil moisture monitoring systems with LoRA technology
Authors: Aji Purnomo Fendi , Maulana Yoeseph Nanang , Alim Tri Bawono Sahirul , Hartono Rudi 
Published: March 2021

Abstract
One of the problems in agriculture is the difficulty of monitoring agricultural field because its location is far from the farmer’s house. Factors affecting agricultural crops are air temperature and soil moisture. Both factors are important to be maintained so that agricultural output can be optimized. LoRA is a spread spectrum modulation technique derived from spread spectrum chirp technology and the first low cost implementation of spread spectrum chirp. LoRA s able to transmit data within a distance of 7.5 km with a frequency of 433 MHz. In this study, machine-to-machine method with LoRA technology was used to send air temperature and soil moisture data. This method is advantageous because communication can be carried out at frequency of 433 MHz and thus does not depend on cellular frequencies. Monitoring via the internet can be done by connecting LoRA with the ESP32 microcontroller which connected to an access point for sending data online through the Ceyene application. Test environment is build by giving variations in air temperature and variations in the depth of the sensor that was planted in the soil. The research proves that monitoring of soil temperature and humidity can be done with LoRA technology at a low cost.
Electrical Signal Propagation in Four Probes System Measuring at The Range of 20Hz - 600Hz
Authors: Hidayat Samsul , Santoso Didik R , Maryanto Sukir , Nadhir Ahmad 
Published: March 2021

Abstract
The electrical-supply on the earth’s surface are propagate from the positive electrode to the negative electrode. The electrons flow from the negative electrode to the positive electrode. In the conductor wire, an electric current tends to pass through the wire shell. The charge density decreases in proportion to the depth, the increase in frequency, and the material permeability. Based on these factors, practically, the conductor surface is often extended by making fibbers. If one of the trajectories on the earth gives an electric voltage, then the earth is not a perfect conductor, the earth as a large object with a surface is predicted to be relatively difficult to deliver an alternating electric current. Based on the previous statement, the granting of an electric current, and will more difficult to flow when the frequency is increased. The aim of this research is to find out the phenomena of earth resistance in the range of 20Hz-600Hz. It is expected that this data are useful for determining the frequency of effective exploration or also as a consideration when interpreting data. The study is conducted by giving an electric field to two electrodes with a measured current. Two electrodes are plugged into the ground for injecting current, and two others electrodes to pick up voltage which was reached. The measurements were made with an oscilloscope. The frequency was varied while recording the current that flow. The current flowed from the square wave current source that could be varied from 20Hz to 600Hz. From this experiment, it is found that the voltage decreases relatives along with the increase in the frequency.
Characteristics of The Type 5076100 Lithium-ion Battery for Integration System of Stand-alone Solar Street Lighting
Authors: Saputra M , Supriyanto A , Ramelan A H , Nugraheni E , Aga A 
Published: March 2021

Abstract
There is still little rearch that pays attention to the problem of integrating battery packs into stand-alone solar street lighting systems. In this paper, we will conduct a study of the characteristics of the 5076100 type Lithium-ion battery for integration systems of standalone solar street lighting systems. The hope of this study can be useful to provide a basic understanding of the integration of battery packs into the stand-alone solar street lighting systems and serve as a reference for selecting battery pack modules. 12-cell lithium-ion type 5076100 will be tested for its characteristics in terms of open circuit voltage (Voc ) and maximum capacity. Next, we integrated the battery pack into 6 model, namely 1S12P, 2S6P, 3S4P, 4S3P, 6S2P, 12S1P. We get the results that the 3S4P model is a battery pack model that is suitable for stand-alone solar street lighting systems. Battery performance is able to provide energy reserves of more than 20 hours for a 7 watt LED load at full charge.
Crystal structure and corrosion properties of alumunium organoclay composite by the hotpress method
Authors: Rofa Z M , Soegijono B 
Published: March 2021

Abstract
Alumunium Matrix Composite (AMC) is a material that has great potential especially in automotive industry. AMC has good corrosion resistance, density, electrical conductivity and heat properties. This paper will study the crystal structure form composite materials and the corrosion properties of the sample. Composite material made with Alumunium as a matrix and reinforcement in the of organoclay variations 0%, 1%, 2%, 3% wt by the hotpress method at 600°C for 1 hour. Characterization of crystal structure and phase using X-Ray diffraction. The corrosion properties of the samples were examine by potentiodynamic curves in 3,5 % wt NaCl solution. The results showed that the addition of weight percent composition of organoclay produce different characteristics and corrosion properties. Corrosion properties can be seen form the rate of corrosion slower along with the addition composition of the organoclay. The smallest corrosion rate results found in alumunium composites with reinforcement variations of 3% by 1,776 x 10−4 mm/year.
Effects of Nd and Mn Co-dopant on the Micro Structure and Optical Properties of BiFeO3 Thin Films Elaborated by Chemical Solution Deposition (CSD)
Authors: Noviastuti M D , Kusumandari  , Suryana R , Iriani Y , Fasquelle D. 
Published: March 2021

Abstract
Bismuth Ferrite (BiFeO3), Neodymium (Nd) and Manganese (Mn) (Bi1-xNdxFe1-yMnyO3) with (x, y = 0.03, 0.03; 0.03, 0.05; 0.05, 0.03; 0.05, 0.05) were prepared by Chemical Solution Deposition (CSD) method at annealing temperatures of 550 °C. The effects of addition of Nd and Mn co-dopants in the BiFeO3 on the crystal structure and optical properties are presented. The results of X-Ray Diffraction (XRD) characterization showed that the addition of Nd and Mn co-dopants leads the diffraction angles to shift to smaller angles and to decrease the crystal size. Doped-BiFeO3 samples were characterized by UV-vis in the wavelength range of 200 nm-800 nm. The transmittance value of Bi1-xNdxFe1-yMnyO3 samples decreased in the wavelength range of 400-800 nm (UV light). The addition of Nd and Mn co-dopants to BiFeO3 caused light dispersion and refractive index to decrease.
The addition of bismuth (Bi) to the barium titanate (BaTiO3) prepared by chemical solution deposition
Authors: Rini R P , Nurosyid F , Iriani Y , Fasquelle D. 
Published: March 2021

Abstract
The manufacture of BaTiO3 thin films and Ba1-xBixTiO3 have been conducted successfully on the quartz substrate using Chemical Solution Deposition method. The results of characterization using XRD showed that the crystals of BaTiO3 and Ba1-xBixTiO3 were perovskite. The diffraction angle shift between BaTiO3 and Ba1-xBixTiO3 shifts to the right as the mole concentration of Bi. The crystallinity of the Ba1-xBixTiO3 sample increases along with the increase of Bi mole concentration. The higher the sample annealing temperature, the crystallinity decreases. The addition of Bi mole concentrations and the increase of annealing temperature in Ba1-xBixTiO3 samples causes the crystal size of the thin film to increase. Lattice strain is greater with the addition of Bi concentration and the increase of annealing temperature. The result of UV-Vis showed that the transmittance of the thin film was relatively small. Therefore, the thin film made has a high ability to absorb light in the UV area. The greater the addition of Bi mole concentration, the greater the ability of light absorption. When the thin film was given an additional concentration of Bi mol, the refractive index value was greater. The addition of Bi mole concentrations in Ba1-xBixTiO3 thin films leads to an increase in dispersion values.
Development of electro-optics method for evaluation of quality degradation of some vegetable oils
Authors: Winarno  , Richardina V , Sugito H , Azam M , Soesanto Q M B , Firdausi K S 
Published: March 2021

Abstract
In this research we present a development of electro-optics effect to evaluate vegetable oil quality degradation. Some vegetable cooking oil samples after heating were placed in an external electric field to obtain the electro-optical characteristics, by measuring the polarization change using green pointer laser (532 nm). The results showed that the change on natural polarization and electro-optics effect were proportional to the duration of heating. An important result showed that the percentage of reduction in the quality of olive oil is the greatest from palm oil, rice bran oil, and corn oil. This provides electro-optics as a very potential method in the cooking oil quality test system and provides a new perspective for further research improvement in other relevant fields.
Mapping flooded risk area in East Java Indonesia using remote sensing data
Authors: Cahyono B E , Cahyatri P , Purwandari E , Misto  , Febrianti N 
Published: March 2021

Abstract
Flooded risk area describes the potential ease of an area to experiencing flooding. Several natural factors such as intensity, duration, and distribution of rainfall, land use / land cover, slope of the area, and soil type can affect the risk of flooding. This study aims to create the flooding risk map level of an area. Those parameters which affect the risk level are classified to be marked and weighted. The equation called Kingma algorithm is then applied to the weighted parameters to get the risk level value. The results are then classified and mapped into 3 classes of risk level that are safe, risky, and highly risk. This study showed that the highly risk areas are located in the flat area, low infiltration soil, and high intensity of rainfall. In contrast, the steep slope areas with high infiltration level of soil and still have a lot of vegetation growing.
Microstructure and corrosion behaviour of ultrafine-grained pure magnesium by severe plastic deformation as a biodegradable material
Authors: Rifai M , Prasetya A D , Mujamilah  , Miyamoto H 
Published: March 2021

Abstract
Microstructure and corrosion behaviour of ultrafine-grained pure magnesium by severe plastic deformation has been investigated in term on initial deformation process as a biodegradable material. Equal channel angular pressing (ECAP) has been chosen as severe plastic deformation which can be introduced into the material without changing the material geometry. The ECAP process was carried out at 523 K. The microstructure was characterized by scanning electron microscope which is equipped by electron backscatter diffraction, and the corrosion behaviour was investigated by electrochemical test. The ECAP processed sample show that the deformation structures has sub boundaries in one pass and a high fraction of high angle grain boundary due to high misorientation in the grain boundaries. The corrosion behaviour exhibited that ECAP processed sample has a lower corrosion rate than that as-annealed sample due to deformed structure.
Physical-chemical and antibacterial properties of green-synthesized silver nanoparticles mediated by leaf extract of Syzygium aromaticum L
Authors: Wattimena S C , Reniwuryaan A A , Patty P J 
Published: March 2021

Abstract
Silver nanoparticles have played an important role in many applications due to their unique properties, and green synthesis of the particles has been a popular choice as opposed to chemical and physical methods. In this study, the physical, chemical, and antibacterial properties of green synthesized silver nanoparticles mediated by leaf extract of Syzygium aromaticum L were examined. Initially, the formation of silver nanoparticles was indicated by the yellowish-brown color of the mixture of the extract and silver nitrate solution, followed by the UV-VIS spectrum of the mixture showing the surface plasmon resonance at 415 nm. The samples then were analyzed using TEM showing the particle diameters varying from 2.9 nm to 33.6 nm with the mean diameter of 20.5 ± 4.9 nm. The FTIR spectrum showed the presence of chemical bonding of organic materials on the particles indicating the involvement of the extract as reducing and capping agents in the formation of the particles. The antibacterial activity on Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were examined using disc diffusion and spectrophotometric methods, and the results show that the silver nanoparticles inhibit the growth of S. aureus and E. coli. Results from the disc diffusion method show that the particles inhibit the growth of S. aureus and E. coli equally, while from the spectrophotometric method, the particles inhibit the growth of E. coli faster than they inhibit the growth of S. aureus.
High power particle accelerator for driving the nuclear waste transmutation system at nuclear power plant
Authors: Pudjorahardjo D S , Wahyono P I 
Published: March 2021

Abstract
The existing technology for treatment of NPP nuclear waste is a deep geological disposal technology. But this technology is still has possibility of leakage due to heating caused by radioactivity process from long lived elements of nuclear waste. The development of high power particle accelerator technology which can produce high power proton beam to induce nuclear spallation reaction has introduced a new accelerator-based technology for treatment of nuclear waste from NPP named the Accelerator-driven Transmutation Waste (ATW). This paper describes result of study on status of accelerator based transmutation system for NPP nuclear waste. ATW is subcritical nuclear reactor combined with high power proton accelerator for transmutation of nuclear waste utilizing neutrons from spallation reaction due to collision of high power proton beam with heavy metal material as spallation target. The types of accelerators used for ATW are cyclotron, linac and synchrotron which able to produce proton beam of 10 up to 100 MW beam power, 10 up to 100 mA beam current and 0.6 up to 1.5 GeV beam energy. Demonstration scale ATW requires 1 up to 2 MW of proton beam power to generate 50 up to 100 MWth of thermal power in subcritical reactor. Whereas industrial ATW requires 10 up to 75 MW of proton beam power to generate hundred MWth of thermal power in subcritical reactor. Several countries have roadmap of ADS research and development which the main goal of nuclear waste transmutation using ADS called ATW. ATW also can be used for electrical energy production which is safer and more reliable.
Study of the Effectiveness of Radiation Retaining Materials for the Entrance of LINAC 6 MV Radiotherapy Room
Authors: Setiawati E , Arifin Z , Richardina V , Setiawan W A , Margiantono A 
Published: March 2021

Abstract
LINAC radiotherapy devices can produce scattering radiation and leak radiation from the gantry. The doses of scattering radiation result from the scattering radiations from the wall (HST) and the patient (HPS). Gantry leak radiation is gantry leak radiation through the labyrinth hall (HLS) and the one that goes directly to the entrance (HLT). These four components play a role in producing radiation doses at the entrance. The scattering radiation in the LINAC 6 MV radiotherapy installation can spread in all directions. Therefore, there is a need for a special review to examine the scattering radiation to the entrance of the room. The constituent of the radiation retaining wall also influences the reflection coefficient of the wall (α). Therefore, it is important to pay attention to the α value in evaluating the radiation dose at the labyrinth entrance. Radiation protection efforts for radiation workers and the community around the radiotherapy room need to be considered by creating a radiation barrier that can minimize the radiation received. With that in mind, the purpose of this study is to examine several possible materials for radiation shielding, especially at the entrance of the radiotherapy room. Materials used for the entrance are lead (Pb), borated polyethylene (BPE), aluminum (Al), and iron (Fe) with a thickness of 6 mm, respectively. The variation of the reflected angle used in the calculation of HST, HLS, and HPS values starts from an angle of 50° to 80°. The result showed that the most effective material for reducing the amount of radiation is lead with effectiveness of 86.79%.