bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chitosan Pesticides for Control Aphids (Aphis craccivora) on High Population in Long Bean (Vigna sesquipedalis) Cultivation
Authors: Adiwena M , Nurmaisah  , Imuly D.P , Rahim A. 
Published: December 2021

Abstract
Pesticides with chitosan as an alternative are still relevant for aphids which are important pesticides in vegetable crops. This research was conducted to see the effect of several types of pesticides with chitosan active ingredients, the concentration of pesticides, and interactions between types of pesticides and concentrations of aphids on long bean plants. The study used factorial methods with randomized block designs. The first factor was the type of pesticide made from chitosan, which consisted of control (JO), pure chitosan (Jl), soft guard (J2), super biovit (13). The second factor was the concentration of pesticides that consisted of 0.1% (Kl), 0.3% (K2), and 1% (K3). There were 48 experimental units consisting of 12 treatment combinations and 4 replications. Data were analysed using Analysis of variance (ANOVA), and comparison between averages using Duncan Multiple Range Test (DMRT). The results showed the effect of the treatment was single or there was no interaction between the types of pesticides made from chitosan with an active concentration in all parameters of observation. Furthermore, the effect of the type of pesticide with active chitosan was significantly different only on the average aphid population I and 3 days after the first application. Whereas pesticides made from active chitosan soft guard type tended to control the aphid population higher than other types of pesticides, then the effect of pesticide concentration was not significantly different from all parameters. However, the concentration of 1% indicated to inhibit the population of aphids higher than other concentrations. The high early aphid population, the behaviour of aphid colonies, the application method, and the nature of the active ingredient of chitosan were thought to be factors that reduce the ability of pesticides to control aphids on long bean plants.
Service Quality and Interest Impact on Satisfaction and Loyalty of Agro Tourism Visitors
Authors: Andayani Sri Ayu , Umyati Sri , Dani Umar , Turnip Arjon 
Published: December 2021

Abstract
The agricultural sector is one of the opportunities for improving the economy of local communities. Opportunities will be a challenge for agro-tourism managers in their development. The purpose of this study was to determine the impact of service quality and importance on visitor satisfaction and loyalty. The research method used is a survey method and research sampling using incidental sampling technique to 127 tourists who come to visit. Furthermore, the data is processed using the Structural Equation Modeling (SEM) method with the support of Amos SPSS Version 24. The results show that good service performance can significantly increase visitor satisfaction by 44%. However, it is inversely proportional to the effect of service performance on consumer loyalty directly. Improved service performance can lower visitor loyalty rates by 48%. In addition, increased satisfaction can also have a significant effect on visitor loyalty by 111%. In contrast to service performance and satisfaction, interests do not have a significant effect on visitor satisfaction or loyalty. So that the presence or absence of complete facilities at the research location does not guarantee that visitors will feel significant satisfaction and loyalty.
Recovery of cobalt and molybdenum from consumed catalyst using hydrochloric acid
Authors: Sutama D K , Prasetya A , Petrus H T B M , Astuti W 
Published: December 2021

Abstract
Cobalt and molybdenum are valuable metals whose presence in nature is very limited. The consumed catalyst, which is abundantly available in the petroleum refinery industry, is a potential source of those metals. A hydrometallurgical process using acid as a leaching agent is usually used to extract and separate the metals more effectively. This method is considered capable of yielding recovery of a higher percentage of metal. In this study, hydrochloric acid solutions at various concentrations of 1.0, 1.5 and 2 M were used. The consumed catalyst was obtained from Pertamina Refinery Unit IV, Cilacap, Indonesia. Leaching experiment was carried out for 300 minutes and sampling was undertaken at 1, 3, 5, 15, 30, 90 and 300 minutes. The particle size and agitation speed were fixed at 200 mesh and 400 rpm. Samples of consumed catalyst were analyzed using EDXRF before the leaching process. Samples of solution were analyzed using ICP-EOS. Experimental results have shown that the recovery of cobalt and molybdenum increases with the increase of either concentration of hydrochloric acid or temperature. The highest recoveries in cobalt and molybdenum were 34.66% and 5.03%, respectively, obtained at a concentration of hydrochloric acid of 2 M and temperature 60°C.
The extraction of tin (Sn) from primary tin ore deposits using wet chlorination
Authors: Rodliyah I , Wijayanti R , Septiarani A , Sudrajat A , Firmansyah D 
Published: December 2021

Abstract
More than half of the world’s tin production is from secondary ore deposits. However, along with its depletion, PT Timah Tbk has explored and mined the primary deposits in Belitung, one that is expected to become tin’s new source. Tin was found liberated as cassiterite in the secondary deposits, while in the primary, it was associated with other minerals requiring more complex processing. Therefore, a suitable technology is needed to extract the tin from the primary ore deposits. This research aims to observe the extraction of tin from primary deposits (oxide and skarn ores) using HCl wet chlorination, observed at different temperature (60 – 90°C), HCl concentrations (10 – 50 % excess of stoichiometric amount), leaching time (60 – 300 minutes), and with or without the addition of oxidant (hydrogen peroxide, H2O2). The research found that the highest percentage of tin extraction from oxide and skarn ores was 92.32% and 97.28%, respectively. Both results were achieved at the same optimum condition: temperature of 60°C, 50% excess of HCl, 240 minutes of leaching time, and at two-fold excess of the stoichiometric amount of H2O2. It was concluded that oxidative wet chlorination could be used to recover tin from its primary ore deposits.
Laboratory test and analysis of recovery from separation of iron sand using magnetic separator
Authors: Permatasari I , Palit C , Subandrio  
Published: December 2021

Abstract
The iron sand mining is a prevalent practice because such a material is a mineral with many uses, including as a raw material in the iron and steel industry. In mining, iron sand certainly carries other minerals as impurity minerals. Thus the iron sand needs a further processing to increase the content of the iron itself. The widely used method is using a magnetic separator since the iron ore is a material that is strongly attracted by magnetic force. In contrast, the impurity material is repelled by magnetic forces so that the separation of iron sand from impurities can be carried out properly. The purpose of this study is to increase the content of valuable minerals available in the iron sand material. The variables used in this study includes the strong electric current and the size of iron sand. This study obtained a maximum result at a material size of 100 mesh with a current strength of 5 amperes with the acquisition of concentrates as much as 165,189 grams and a recovery value of 65,041%.
Characteristic of heat transfer nanofluid of Al2O3 improved by ZrO2 addition
Authors: Gustaman Syarif Dani , Usman Jakaria , Ike Pratiwi Yofi , Yamin Muhammad , Hardian Arie 
Published: December 2021

Abstract
Efforts to replace conventional fluids as coolants for heat transfers with new fluids are continuously being made to improve heat transfer efficiency. Nanofluids are currently widely studied around the world as candidates for conventional fluids substitutes. In this research, the synthesis of Al2O3-ZrO2 nanocomposites for heat transfer nanofluid applications was carried out. The synthesis of the nanoparticles was conducted by the hydrothermal method. Here, we used ZrO2 to improve the characteristics of Al2O3. The results of XRD analysis showed that the nanocomposite had an Al2O3 gamma structure. The Al2O3 nanoparticles and Al2O3-ZrO2 nanocomposite have a crystallite size of 7.41 nm and 6.84 nm, respectively. The addition of 0.1 % ZrO2 decreased the crystallite size and BET particle size and increased the zeta potential, hence the stability of the nanofluids. The increase of stability increased the heat transfer coefficient of the Al2O3 nanofluids, making them suitable for heat transfer.
Analysis of cyclic voltammetry in the recovery of copper from printed circuit board waste using diluted deep eutectic solvent
Authors: Sugondo E , Harjanto S , Ulum R M 
Published: December 2021

Abstract
Cyclic voltammetry has been successfully analyzed from a diluted deep eutectic solvent (DDES) electrolyte for recovery printed circuit boards (PCB) containing 17.91% copper. The raw material sample is made through the dismantling stage until the grinding and then sieved to 80 mesh size for testing samples. Temperature variations are used to increase the surface area of the electrodes. The temperature variations used were 40⁰C, 50⁰C, and 60⁰C. The cyclic voltammetric measurement method was carried out using the potentiostat / galvanostat autolab PGSTAT302N connected to a computer with NOVA 1.11 software and a DC power source used for electrolysis with a scan rate of 10 mV / s. From the measurement results, it was found that the largest capacitance value was at 60⁰C with an oxidation peak of 1.15 A. with a current efficiency of 99.83%. Additional testing was also carried out using SEM-EDX to see the morphological surface of the cathode used.
Effect additional pH on separation extraction gadolinium from terbium and europium with Di-2-(ethylhexcyl)phosphate acid
Authors: Budiman S , Saputra B , Hardian A , Yuliana T , Murniati A , Kusumaningtyas V A , Nurdeni  , Effendy S , Mutalib A , Anggraeni A , Bahti H H 
Published: December 2021

Abstract
Rare earth elements are strategic materials, difficult to obtain, and have wide uses. Currently, it is still difficult to separate and refine REE’s because it has similar physical and chemical properties. Solvent extraction is most successful method used for the separation of REE’s. Di-2-ethylhexyl phosphoric acid has been widely used in industry for the separation and of REE’s. Purpose of this study is effect of pH on basic parameters extraction which include distribution coefficient, extraction efficiency and separation factor in extraction gadolinium, terbium and europium through complex with D2EHPA. Determination effect pH is a parameter determined in process extracting standard solutions gadolinium, terbium and europium using D2EHPA with n hexane. Basic parameters in extraction gadolinium, terbium and europium with D2EHPA at pH 4 are as follows KdGd = 89.90; αGd/Tb = 5.63, Gd/Eu = 1.83; %E = 98.90. KdTb = 15.94; αTb/Gd = 0.17; Tb/Eu = 0.32; % E = 94.10; KdEu = 1.40; αEu/Gd = 0.01, Eu/Tb = 0.08; %E = 98.29. From these valuesit can be concluded that gadolinium, can be separated from terbium and europium by the solvent extraction method by forming complex D2EHPA with best separation results obtained at pH 4.
Study of making coal water slurry with lignite Pendopo coal
Authors: Rahmanta M A 
Published: December 2021

Abstract
The Coal Water Slurry (CWS) technology increases the calorific value and changes the phase of coal from solid to liquid. The CWS Plant with a coal capacity of 1.4 t/hour located at Karawang, West Java converts lignite coal to CWS. Coal undergoes pulverizing, upgrading, and slurry-making processes to become CWS. Pulverization is the process of refining coal size into 200 mesh. The upgrading process is through reducing the moisture content in heat exchangers (HE). It occurs in HE where the coal is pressurized to 15 MPa and the temperature is maintained at 330 0C for 30 minutes. The research objective was to determine the CWS characteristics of the South Sumatra Pendopo lignite coal. The method used is through testing where the Pendopo coal is converted into CWS at the CWS Plant. The result shows that Pendopo coal which has a heating value of High Heating Value (HHV) 2,725.00 kCal/kg As Received (AR) has an increase in HHV heating value of 3,218.00 kcal/kg AR when it becomes CWS. The total moisture content of Pendopo coal has decreased from 49.36% to 44.58% when it becomes CWS. The fixed carbon content of Pendopo coal increased from 19.78% AR to 24.01% AR.
Fitting the variogram model of nickel laterite using root means square error in Morowali, Central Sulawesi
Authors: Anggara Benny , Marwanza Irfan , Ahmad Azizi Masagus , Dahani Wiwik , Subandrio  
Published: December 2021

Abstract

Abstract. The nickel commodity is getting popular due to its role as one of the raw materials for battery manufacture. It is estimated that this trend will continue for the next 2 - 3 years and reaching its peak when the factories that process the raw material for electric vehicle batteries are established. For this reason, the nickel mining companies are competing to explore new nickel deposits. The research location is a nickel mine in Sulawesi. The purpose of this study was to determine the most suitable Nickel variogram model based on root means square error (RMSE). To obtain an accurate number of resources, it is necessary to apply an accurate and validated estimation method to gain data that are in line with the actual conditions. Therefore, this study uses a geostatistical method that takes into account the spatial relationship of each data using a variogram which is validated by the cross-validation method and RMSE. From the results of the RSME analysis, the most suitable variogram model for nickel content in the limonite and saprolite layers is the exponential variogram model. In addition, the values of root mean square error for nickel content in the limonite and saprolite layers were 0.022 and 0.098 respectively.
The planning of mine drainage system at PT Perkasa Inakakerta, East Kutai Regency
Authors: Dewi M C , Anggara R , Hidayatullah R , Nurhakim I 
Published: December 2021

Abstract
This research located in Beruang Block Kalimantan. The purpose of the mine drainage planning system is to control runoff water. Therefore, an excellent drainage system is needed without interfering with mining activities such as runoff water pollution, which could cause contamination in the surrounding area and outside the mining sites. Based on the analysis of rainfall data of 2009-2020, the precipitation plan was 341.67 mm/day; the concentration time was 2.37 h, the rain intensity was 41.06 mm/h, and repeated rain periods were 2-years. The extensive catchment area was 1.52 km2 because the runoff entering the sump was 44.38 m3/h. To prevent the water from entering the mining area, an open channel was made around the mine openings, and the water flows naturally into the sump. The water pumped into the settling pond with the pump type Allight HL 150MHD-IT at 50 m/s for 3-days with a single rain, resulting in total water volume of 17,556.5 m3/day. A trapezoidal shape was designed for a sump with dimensions of 3.96 m in length and width at the surface, 1.79 m length and width at the base, and 1.03 depth.
Slope stability and bearing capacity analysis of disposal in open-pit coal mining
Authors: Sirait Bagaraja , Zulfahmi  
Published: December 2021

Abstract
Open-pit mine is a mining method by excavating overburden strata to get coal seam near the surface. One of potential hazard often occur in mining area is slope failure. The hazard can be prevented by performing geotechnical study. The study is required to provide recommendations regarding safe design of slope geometries in both open-pit and disposal sites. This paper produce information related to the results of slope stability analysis especially on the disposal embankment. The analysis is performed by using the limit equilibrium method. It is also produce the bearing capacity analysis of subsurface strata in disposal site. The analysis is carried out to determine the ability of the strata to burden the load of disposal embankment above. The location was selected in a site of open-pit coal mine in Indonesia. The results will become consideration for management in designing slope disposal and choosing the location of disposal facilities.
Removal of mercury ion from wastewater using natural zeolite: effect of humic acid to adsorption isotherm
Authors: Prasakti L , Utami F N , Prasetya A 
Published: December 2021

Abstract
As Indonesia possessed a considerable amount of gold deposit, many golds mining activities, including the small-scale one, is commonly found. A simple mining technique (amalgamation) that utilizes mercury (Hg) will generate mercury-containing wastewater. One of the prospective Hg removal methods from wastewater is adsorption. In addition, it is also possible that metal contained in the wastewater interacts with other substances, such as humic acid. This experiment was aimed to examine the adsorption process of Hg2+ ions in the wastewater using natural zeolite. The effect of the presence of humic acid, which might be found in sewage, toward the adsorption capacity of Hg2+ onto natural zeolite was investigated. The natural zeolite, which contained several types of minerals, was obtained from Klaten, Central Java. The experiment was conducted using ten mg/L HgCl2 as the initial concentration and ten mg/L humic acids. A comprehensive study that includes isotherm and the kinetic study was carried out. Experimental results showed that the presence of humic acid was found to reduce the capacity of Hg2+ adsorption on natural zeolite. Freundlich isotherm model was found to be more suitable to represent equilibrium adsorption data. Kinetic examination revealed that the pseudo-second-order model was able to produce a better agreement with experimental data.
Prospect of coal-based methanol market in Indonesia
Authors: Suseno T , Umar D F 
Published: December 2021

AbstractCoal is one of the commodities in the mining sector which is currently being pushed to strengthen the structure of the upstream petrochemical industry, including methanol as a raw material for various derivative industries, most of which are still imported. Currently, Indonesia has only one methanol plant with a production capacity of 660,000 tons. During 2023-2035, Indonesia needs an average of 1.77 million tons of methanol per year. If, until 2035, Indonesia does not add and build a methanol plant, then Indonesia will always import 1.51 million tons per year. Results indicate that the methanol plant, through coal gasification, can support the growth of the methanol-base industry to reach domestic needs and reduce imports. It can also as an export commodity to generate foreign exchange.
Business analysis of implementation of UCG technology in Indonesia
Authors: Kurnia Hudaya Gandhi , Huda Miftahul 
Published: December 2021

Abstract
There is a deep-seated coal potency with a depth more than 100 meters below surface in Indonesia that has not been exploited yet. Underground Coal Gasification (UCG) is an unconventional technology that can become the solution to exploit the deep-seated coal potential by extracting coal into in-situ gas that can be converted to electricity or chemicals. Based on business analysis, this paper aims to analyze the implementation of UCG technology in Indonesia, whether it is potential or not. Data are collected from literature and analyzed using Porter Five Forces and PESTLE Analysis. The Porter Five Forces analysis shows that the implementation of UCG in Indonesia is still potential as an industry because the only threat will come from substitute products. PESTLE analysis shows that almost all the factors, except for technology, are very supportive of implementing UCG commercial plants in Indonesia. Based on both studies, it can be concluded that the UCG project is very potential to be developed in Indonesia. However, it needs full support and control from the government because it will become a pioneer project with financial and environmental risk still has not quantified ideally.
Automation Design of Kentongan Sound for The Feeding Process of Vaname Shrimp Farming in Pond
Authors: Waryanto W , Zulkarnain R 
Published: December 2021

AbstractFeeding on vanamei shrimp culture in pondsis carried out on average 4 to 5 times a day. In aquaculture activities with a large number of ponds, the sound of kentongan becomes a time reference for the operator in providing feed. The purpose of this article was to describe the process required to turn the kentongan sound into a command input for an automatic feeder. The sound of kentongan will be used as input data (commands) for the microcontroller is translated as a command for the feeder to carry out its activities of feeding. The methodology used the following points: first, field observations of the use of kentongan sounds as a sign of the feeding process for feed operators; second, literature study covering sound frequency and sensor system; third, the creation of a chart in the form of step by step logic from input in the form of kentongan sounds to the process of feeding using an automatic feeding device; fourth, the design of the hardware that will be used and the creation of the software in the form of a command flow chart. The result was realized in the form of a chart from input in the form of kentongan sounds to the process of feeding using an automatic feeder. This includes hardware and software design. There were two important things in automation design. The identification process of kentongan sounds becomes a function of frequency against time, where this frequency had certain characteristics which were expressed by graphs that have certain equation values. This kentongan sound with a certain frequency will be the input for the microcontroller to carry out its task of giving orders to the feeding device to provide feed for vanamei shrimp in ponds.
Quality Improvement of Water Hyacinth (Eichornia Crassipes) Leaf Meal Fermented with Aspergillus Niger as Fish Feed Ingredient
Authors: Suharman I , Lukistyowati I , Ramayani S , Caipang C M A , Adelina A , Aryani N 
Published: December 2021

Abstract
An experiment was conducted to investigate the nutrient quality of water hyacinth leaf meal (WHLM) fermented with different doses of Aspergillus niger as fish feed ingredients. This study utilized a completely randomized design (CRD) with five treatments and three repetitions. The doses of A. niger supplemented in WHLM were 0; 6; 8; 10; and 12%. Results of this study showed that nutrient quality of WHLM with A. niger supplementation significantly affected the reduction of crude fiber and increase of crude protein (P<0.05). Addition of 12% A. niger is the best treatment for improving protein and fiber quality of water hyacinth leaf meal.