bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of demineralization towards gasification performance of low-rank coal
Authors: Rizkiana Jenny , Ananda Reyhan Fitri , Kamilah Nasywa , Aulia Ghiffary Azka Nur , Maulana Sandy Fajar , Zahra Aghietyas Choirun Az , Wulandari Winny , Sasongko Dwiwahju 
Published: May 2020

Abstract
Gasification process is an alternative way to utilize low-rank coal. However, gas production is not very high due to the high content of volatile matters and high mineral content. One interesting way to increase gas production is by reducing the mineral content in the coal by acid leaching process. In the present study, acid leaching is occupied to pre-treat the coal by using HF solution so that the mineral content in the coal can be leached out. The results show that acid leaching process successfully decreased the ash content in the coal. However, in terms of gas production, it appears that acid leaching slightly decreases the total gas production. It could happen since acid processing of coal might increase its crystallinity and thus it becomes more difficult to be gasified.
Green diesel production from Crude Palm Oil (CPO) using catalytic hydrogenation method
Authors: Zikri Ahmad , Aznury Martha 
Published: May 2020

Abstract
Green diesel is an alternative solution for solving problems using biomass energy as a fuel source. The advantages of this second-generation green diesel or biodiesel (Gen-2nd) are capable of reaching cetane numbers 70-90, far higher than the Gen-1st biodiesel performance of cetane numbers 50-65, respectively. The production process is through hydrogenation reactions with hydrogen injection of 4-9 MPa, the use of heterogeneous NiMo/Al2O3 catalysts, and takes place in temperatures of 280 - 380°C. The need to design this catalytic hydrogenation reactor to convert crude palm oil (CPO) into green diesel fuel is good and safe when operating at high pressures and temperatures. The optimum operation was obtained by varying the amount of CPO oil raw material and NiMo/Al2O3 catalyst used in producing the best percent yield and green diesel characterization. At a temperature of 315°C, the highest yield was 68.2%, where the number of products began to decline above these temperature conditions. The green diesel specifications obtained have met diesel oil standards (Directorate General of Oil and Gas, 2016) by testing density, kinematic viscosity, water content, flash point, calorific value, and cetane numbers.
Effects of coal and biomass types towards the quality of hybrid coal produced via co-torrefaction
Authors: Rizkiana J , Zahra A C A , Wulandari W , Saputra W H , Andrayukti R , Sianipar A M , Sasongko D 
Published: May 2020

Abstract
Coal is an abundant source of energy in Indonesia, but the reserves are dominated by low-rank coal, which is less favorable to be utilized. Indonesia also has various biomass that has potential to be used as an alternative energy source. Combining low-rank coal and biomass in a co-torrefaction process resulted in hybrid coal: an upgraded solid fuel that has higher calorific value than its original coal. The aims of this research are to analyze the effect of different biomass and coal blends on hybrid coal yield, calorific value, energy yield, and non-neutral CO2 emission reduction. This study utilized two types of coal that are X and Y, and three different types of biomass: (a) sugarcane bagasse, (b) rubberwood, and (c) empty palm fruit bunch that are being most widely found in Indonesia. The blends consist of 30%wt biomass were co-torrefied in a vertical tubular furnace reactor for 60 minutes with temperature 300°C in an inert environment and ambient pressure. Solid yields of hybrid coal founded in the range of 57.0 to 63.8% which different types of biomass gave significant effect. Calorific value was increased 37.6-44.1% to 5681-6288 kcal/kg from its original coal. The energy yield ranges from 77.0 to 89.0%. The product reduced non-neutral CO2 emission within the range of 18.1-22.2%.
Lithium and Calcium recovery by activated carbon from coconut shell char
Authors: Purnomo C W , Widyadhana A 
Published: May 2020

Abstract
Spent rechargeable batteries and electronic waste become a future challenge. The precious metal inside should be recovered for pursuing a circular economy society. Here, lithium phosphate battery has been dismantled and leached the cathodes by acidic solution to produce metal solutions. The metal content will be separated by a simple adsorption mechanism using activated charcoal. Coconut shell char has been activated by KOH in several temperature settings and then tested to adsorb lithium and calcium ions in the leaching solution. The capacity of adsorption and selectivity between the ions were investigated. The adsorption capacity is strongly related to the activation temperature and KOH/char ratio. Higher activation temperature and agent ratio tend to provide better-activated carbon for metal ion adsorption. It is found that Li ions have lower affinity toward the surface of carbon especially in low concentration than Ca ions.
Oil palm empty fruit bunch ash valorization through potassium extraction
Authors: Samadhi Tjokorde W. , Wulandari Winny , Tirtabudi Kezia R. 
Published: May 2020

Abstract
Oil palm empty fruit bunch (OPEFB) is a by-product of palm oil processing that is considered solid waste. It is produced in a large amount, counting up to 23% of the fresh fruit bunch (FFB). The ash content in OPEFB comprises a potassium compound. Potassium can be potentially recovered as potassium carbonate by extracting it with water. This study aims to investigate a method to recover potassium from OPEFB ash as potassium carbonate for further processing into potassium-based fertilizer. This research consists of pyrolysis process of OPEFB into char, then the char is analyzed by TGA in order to determine the ashing temperature. The temperature of 250°C, 400°C and 550°C are chosen for the ashing (combustion) process. The resulted ash is then extracted by water with the Feed to Solvent ratio of 1:4, 1:5, and 1:6, respectively. From the AAS analysis result, the highest potassium concentration is obtained at temperature of 400°C with F:S ratio = 1:6, with the potassium concentration of 49,94 %-w/w. This value is suitable for liquid fertilizer.
Plant extract-assisted biosynthesis of zinc oxide nanoparticles and their antibacterial application
Authors: Rahayu E , Wonoputri V , Samadhi T W 
Published: May 2020

Abstract
ZnO nanoparticles are multi-purposes materials that can be synthesized by several methods, including physical and chemical routes. A novel synthesis method of ZnO nanoparticles is the biological method using plant extracts as reducing and capping agents, such as the fruit extract of Averrhoa bilimbi. Plant extracts are superior agents for synthesizing nanoparticles because it provides essential phytochemical substances as reductor, capping agents, and free from toxicants. In this study, the effects of precursor concentrations and the amount of plant extract on the formation and morphology of nanoparticles were investigated. The characteristics of ZnO particles were studied by UV-Vis spectroscopy, XRD, FTIR, TEM, and DLS. The study showed that the formation of ZnO nanoparticles occurred after five hours reaction at 70°C, as indicated by color change of the solution. ZnO nanoparticle formation was confirmed by the maximum absorption at the wavelength of 372 nm and XRD analysis. FTIR analysis showed that the as-synthesized ZnO contained significant organic compounds on its surface, especially compared to commercial ZnO. Reduction reactions using A.bilimbi produce nanoparticles in the size from 35.4 to 59.5 nm with round shape and some agglomeration that were observed by TEM. The ZnO antibacterial property was tested against planktonic and biofilm Escherichia coli. The result showed that as-synthesized ZnO have comparable antibacterial antibiofilm property as the commercial ZnO nanoparticles at low concentration. Interestingly, this property was diminished when as-synthesized ZnO nanoparticles were used at high concentrations.
Identification of plants natural dye by Meto tribe in South Central Timor
Authors: Charis Sabuna Alan , Nomleni Fransina T. 
Published: May 2020

Abstract
Information on plant species, natural dyes and the dying process of the yarn of ikat weaving in South Central Timor is still minimal and not well documented. Therefore, this study aimed to identify natural dye in South Central Timor. The samples were collected by exploration methods. Parts of plants, dyeing processes, and kinds of color were recorded based on observation, interviews with craftsmen and documentation. Our results showed that there are 7 plant species were successfully identified, Curcuma longa L., Indigofera tinctoria L., Morinda citrifolia L., Phyllanthus reticulates Poir, Phaseolus lunatus L., and Tectona grandis. The plant organs used as a source of natural dye are leaves, barks, rhizome, and roots. The method of processing was to be pounded, squeezed, soaked in water and the color produced was red, dark blue, yellow, black, and green.
Upscaled synthesis of carbon nanotube from palm oil mill effluent using pyrolysis for supercapacitor application
Authors: Widiatmoko P , Nugraha N F , Devianto H , Nurdin I , Prakoso T 
Published: May 2020

AbstractThe utilization of Palm Oil Mill Effluent (POME) is advantageous to reduce environmental problems and increase its value as a source of carbon. Carbon nanotube (CNT) was synthesized by pyrolysis of POME and ferrocene mixture at 900°C under a flowing nitrogen atmosphere. CNT is nanosized and has high electrical conductivity; it is compatible as electrodes for energy storage devices such as supercapacitor. The study investigated the process for the upscaled formation of CNT from POME. The synthesis consists of POME polymerization, pyrolysis, and CNT characterization. Additionally, before pyrolysis, the CNT collecting system was applied in tube furnaces. The result showed that this process produced 1.2 g of CNT, a diameter of 47-100 nm, and a surface area of 635.5 m2.g-1. XRD analysis, 2Ɵ of 26.58° indicated structure of graphite C (002), Raman spectra resulted ratio IG/IDof 1.16 indicated higher graphite than disorder. CNT was characterized and applied as electrode material for supercapacitor which exhibits a specific capacitance of 13.98 F.g-1.
Kinetic studies of turpentine isomerization using hydrochloric acid and acetic acid as catalysts
Authors: Azis Muhammad Mufti , Qani’a Farahfestura Rio , Pratiwi Suci Indah , Kristanto Jonas , Purwono Suryo , Indarto Antonius 
Published: May 2020

Abstract
Turpentine is a non-wood forest product derived from pine trees. Turpentine oil can be produced from the distillation of pine tree sap (family Pinaceae). The main component of turpentine is α-pinene, and turpentine isomerization may produce various derivative products. The objective of the present study was to investigate the isomerization products of turpentine oil with two acid catalysts: hydrochloric and acetic acid. Here, the influence of acid concentration was investigated by using various concentrations of hydrochloric and acetic acid concentrations between 0.4 to 1 M. Further, the combination of acetic acid and hydrochloric acid as catalyst was also investigated by varying the molar ratio of HCl:Acetic Acid=1 : 0.5 and 1:1. The experiments were carried out in a batch reactor equipped with heater, condenser, and stirrer. The reaction temperatures were maintained at 150°C and reaction time of 6 h. The resulting products from turpentine isomerization were analyzed using GC-MS. The results showed that the largest isomerization product obtained with HCl and combination of HCl:H.Acetic was trans sabinene hydrate. Additional products that could be detected varied among α-terpinolene, α-terpineol, α-terpinene, γ-terpinene and δ-carene. The experimental data showed that α-pinene conversion as high as 62, 63 and 57% were obtained by using HCl concentrations of 0.4, 0.7 and 1 M, respectively. In addition, the use of HCl:H.Acetic=1 :0.5 and 1:1 gave final conversion of 63 and 61%. The modeling results showed the kinetic model for pinene conversion for both catalysts was

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Calcium soap from Palm Fatty Acid Distillate (PFAD) for ruminant feed: The effect of CaO quality on reaction temperature
Authors: Handojo Lienda A. , Indarto Antonius , Shofinita Dian , Stanley Nicholas George , Karen  , David Ignatius , Jorgensen  
Published: May 2020

Abstract
Indonesia is the largest palm oil producer in the world and contributes to about 58% of the world’s total palm oil production in 2018. Palm fatty acid distillate (PFAD) is a palm oil refining by-product that contains lots of free fatty acids. Previous research related to the production of calcium soap has successfully found the right stoichiometry and operating conditions at the laboratory and bench scale. This research examines the influence of CaO active concentration on the reaction temperature of calcium soap production on the pilot scale. First, molten PFAD, CaO solids, and water are feed into a CSTR. The mixture is discharged from the CSTR to the screw reactor at a certain temperature, which is then released to the belt conveyor. The experimental result shows that the rate of temperature increment of the mixture using CaO with an active concentration of 79% is greater than CaO of 72%. This may be caused by the different amounts of heat released during the reaction, viscous mixture properties which then influence the mass transfer process between the reaction components. The result also shows that there is a 14% - 19% difference between the calculated and measured temperature, which is predicted due to heat loss, particularly caused by water evaporation during the reaction.
Production of valuable chemical compounds isolated from plants by endophytic fungi
Authors: Ola Antonius R B 
Published: May 2020

Abstract
Natural products have always been an integral part of medical therapy. Many drugs have been developed from natural products mostly derived from plants. For example, the most effective anticancer compounds such as anthracyclines, vinblastine, vincristine, paclitaxel and camptothecins are produced by plants. However, productions of these highly valuable compounds have threatened the existence of the plants as it requires a large number of materials from plants. This paper highlights the potential and importance of endophytic fungi as the producers of highly valuable compounds as it needs only a small amount of material from plants. For example, anticancer drugs like paclitaxel, vincristine and vinblastine were more commonly found in endophytic fungi than in plants.
Ethnobotany study of lontar tree (Borassus flabellifer L.) at Raijua Island
Authors: Age D L , Hendrik A Ch , Rupidara A D N 
Published: May 2020

Abstract
The aims of the study were to determine the utilization of Lontar Plant (Borassus flabellifer L.), its organ used in relation to the culture of the Savu community. Data were collected using semi-structured techniques interviews, field observations, questionnaires, preference and direct matrix ranking with an index of cultural significance. Data were analyzed to calculate the index value of cultural significance which was included 3 aspects, namely the use-value (q), the intensity value (i), and the exclusivity value (e) of the plant and were described qualitatively. The results showed that the utilization of plants in the cultural life of the Savu community was very high. The utilization of plant parts was carried out by cutting, slicing, tapping and weaving. The parts mostly used were the roots, stems, stalks, leaves, flowers, and fruit.
Insect diversity profile of mangrove ecosystem in Menipo Nature Tourism Park, East Amarasi, East Nusa Tenggara
Authors: Semiun Chatarina Gradict , Lengur Eufrasia R. A. , Boli Duhan Gaudensius U. U. 
Published: May 2020

Abstract
Insects are one of the biotic components that make up the mangrove ecosystem. The diversity of insects is believed to be used as one of the bio-indicators of the condition of the mangrove ecosystem. This study aimed at determining the profile of insect diversity in the mangrove ecosystem in Menipo Nature Tourism Park, East Amarasi, East Nusa Tenggara. The study was conducted in February 2018 to June 2018. Insect capture was carried out using the yellow pan trap method. Data analysis was done quantitatively to determine the profile of mangrove insects. The profile of mangrove insect diversity was determined based on species richness index, Shannon-Wienner diversity index, evenness index, and Jaccard similarity index. The results showed that there were 14 species, 11 families, and 5 orders with a total number of 56 individuals in mangrove ecosystem of Menipo Nature Tourism Park. Genetic wealth of mangrove buffer was still relatively low (R1 <3.5). The diversity of mangrove insects was classified as moderate (H’ = 1 - 3). All mangrove insects had almost the same level of evenness (E <1). The similarity index of mangrove insects in Menipo Nature Tourism Park, East Amarasi ranges from 0.18 to 0.5, meaning that the similarity of mangrove insect species among the three stations was different from each other.
Electrochemical reduction of CO2 to Formic Acid on Pb-Sn Alloy Cathode
Authors: Widiatmoko Pramujo , Nurdin Isdiriayani , Devianto Hary , Prakarsa Budi , Hudoyo Henry 
Published: May 2020

Abstract
Carbon dioxide released to the atmosphere due to fossil combustion needs to be reduced to decrease the global warming effect. Electrochemical reduction of CO2 is one of promising technology to convert CO2 to various valuable compounds, reducing the amount of released CO2 to the atmosphere. Metal alloys are interesting material for cathode. In this preliminary work, a CO2 electrochemical reduction was performed on a Pb-Sn alloy cathode using catholyte of KHCO3 and NaHCO3 at various concentrations. An anode from Pt-Ir and H2SO4 0.1 M as anolyte were used in the experiment. The CO2 was bubbled into 400 mL catholyte at rate of 75 mL min-1. It was found that Pb-Sn alloy in KHCO3 electrolyte provides higher productivity and faradaic efficiency than in NaHCO3. Increasing overpotential from 0.1 V to 1 V increases both formic acid productivity and efficiency. The optimum amount of formic acid produced was 9400 μmol in catholyte KHCO3 0.5 M with faradaic efficiency of 67.19% and conversion of 0.326%.
Study of sides stamping under one-sided magnetic pulse loading on form blocks of various materials
Authors: Bobin K N , Detinov M B , Ahmed Soliman M E , Kurlaev N V 
Published: May 2020

Abstract
In this paper, the influence of the tooling material on the accuracy of forming the resulting aluminum alloy part under one-sided magnetic pulse loading was estimated. As the materials of the form blocks were used: dry pine, steel 45 and PLA-plastic. Numerical simulation was carried out using the ANSYS software package in the Explicit Dynamics module. Studies have shown the dependence of the nature deformation of the workpiece and the final geometry of the resulting part from the mechanical properties of the form block materials.
Environmental management in automated systems for engineering production
Authors: Zhetessova G S , Yurchenko V V , Nikonova T Yu , Zharkevich O M , Savelyeva N A 
Published: May 2020

Abstract
The article describes the issues of environmental management and environmental savings. The goal of environmental management is to conserve and save raw materials, materials, energy resources, and to improve the environmental situation. This article describes the technical aspects of environmental management in mechanical engineering production. Identification of environmental aspects occurs on the basis of the process approach. To manage aspects of environmental management in engineering production an automated program “Coating Mode Solver” has been developed. The program interface is described. Automated program selects the optimal technical modes of the process. Optimal process modes allow managing environmental aspects, reducing resource consumption and having a positive impact on the green economy.
Stress state of two-layer composite elements of curved shape
Authors: Koryagin S I , Sharkov O V , Velikanov N L 
Published: May 2020

Abstract
Two-layer composite structures consisting of a metal base and a polymer coating are widely used in mechanical engineering. To assess the bearing capacity and durability of such structures, methods for calculating their stress-strain state are necessary. The paper theoretically investigates the stress state of a two-layer structural element of a curved profile for two variants - under pure bending and under temperature change. The radial and meridional stresses arising in the polymer coating and the metal base of the element are taken as the studied factors. The geometric, strength, and physical characteristics of the structural element are accepted as the independent factors. Mathematical models are obtained using the plane section hypothesis. The authors investigated how the radial and meridional stresses acting in the polymer coating are related to the ratio of the coating and the metal thicknesses, as well as the metal thickness to the curvature radius. It has been established that the curvature of the metal element and the ratio of the layers thickness have the most significant effect on the magnitude of the radial stresses, and the ratio of the thicknesses on the meridional stresses. The stress state of the polymer coating is mainly determined by the ratio of the metal thickness to the radius of curvature of the boundary layer.
Study of structure and physico-mechanical properties of welding joints on vessel tank of austenite steel SS316
Authors: Stoyanova A M , Mechkarova T M , Argirov Y B , Konsulova-Bakalova M I , Atanasov N M 
Published: May 2020

Abstract
The article addresses some problems related to the occurrence of cracks and defects in welding joints on a horizontal steel vessel tank after machine gas metal arc welding (GMAW). Tests have been carried out on the structure and mechanical properties of the welding joints between the cylinder and elliptical bottoms made of austenite steel SS316 according to AISI (X5CrNiMo17-12-2 according to BDS EN 10088-2). Proven methodologies of microstructural and X-ray analysis were used to investigate the changes in the structure (weld seam, heat affected zone and base metal). The mechanical characteristics are determined by measurements of macro- and micro-hardness by Vickers and of static tension.
Grinding specifics of plasma coatings melted with high-frequency currents
Authors: Zverev E A , Skeeba V Yu , Vakhrushev V , Lobanov D V 
Published: May 2020

Abstract
This paper presents the research into the finishing treatment of plasma sprayed nickel coatings hardened by high-energy heating with high-frequency currents. We analyzed the coatings surface topography images and profilograms of the after grinding. The coatings were melted at various specific power values and samples traverse speeds relative to the inductor. We also described the different types of surface structural modifications that are formed depending on the melting mode parameters. The research revealed that high-temperature treatment within the efficient range of technological modes results in forming a dense homogeneous structure in the coating with minimal number of pores. The polished surface of such molten coatings has a regular microrelief and a low level of roughness (Ra = 0.305μm). These properties are achieved owing to a significant increase in the structure qualitative properties during the melting process.