bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Seeding and Planting Scheduling Algorithms for Contract Farming of Organic Vegetable with Multi Seeding and Planting Center
Authors: Putri M M , Mardhiyyah Y S , Rusdiansyah A 
Published: November 2019

Abstract
Organic vegetables are perishable products with special characteristics because its shelf life is influenced by product characteristics, environmental conditions and production time. Customer only buys fresh organic vegetables because its price is more expensive than the non-organic ones. The scheduling of seeding and planting process becomes the most important thing for organic vegetables producer. They must ensure the right time and good condition in organic vegetables consumer delivery. An organic vegetable products company is implementing a contract farming system. They have some Planting and Seeding Centers (PSCs) across several cities. PSC is an organization which cooperate with farmers in contract farming. The functions of PSC are to seed, distributing the seeding result to farmers, packing vegetables form farmers and shipping vegetables to customers. Farmers will plant the seeds received from PSC based on a schedule given by PSC. This research will develop an algorithm of seeding and planting scheduling by PSC and farmers. There are several types of vegetables: vegetables with seeding, vegetables without seeding, planted inside green house, and planted in an open field. PSC and farmers are determined by the nearest distance to customers, the availability of green houses and open fields. The purpose of this algorithm is to optimize PSC seeding and planting scheduling, so we can minimize production costs (seeding, planting, packing and distribution costs) and maximize profits.
The Effect of 45º Upward Flow Straightener Position on Flow Uniformity in Sampling Point of Chimney
Authors: Puspitasari D , Sihombing R , Bunyamin  , Ellyanie  , Marwani  
Published: November 2019

Abstract
Air pollution is one of the factors that can cause the decreasing of air quality in urban areas, especially in areas close to the industry. The government made a policy for the industrial sector to conduct the emission quality measurements in their operating chimneys. Commonly, the quality of emissions from the chimney sampling point is still above the permissible threshold. This condition occurs due to the lack of uniform emission flow near the sampling point. Based on the EPA method, the exhausted gas flow condition near the sampling point must have uniform velocity and small helicity. Therefore in this study the author tried to modify the channel in the chimney by installing a flow straightener (FS) in order to reduce helicity and the degree of uniformity of the flow. The upward 45° FS was chosen. For further research, position of flow straightener at a chimney vertical distance was set at 0.75D, 1D and 1.25D from lower disturbance. Based on the computational results, the best KV value of 32.32% with FS 1.25 D and KV value of 35.52% with 0.75 D were obtained. The closer to the sampling point, the KV value will improve. This result indicated that the accuracy of measurement of emission quality at the sampling point can be improved.
The Influence of Electric Current and Electrolyte Solution on Porous Characteristics on Aluminum Anodizing
Authors: Zulaida Y M , Ramadhannisa A H , Dwiyanti Y 
Published: November 2019

Abstract
For decoration purposes, aluminum metal has widely used metal coloring techniques to enhance the aesthetic value of the metal. Most coloring techniques of the aluminum metal use aluminum metal dipping with dye or with chrome (Cr) directly. This coating technique has the disadvantage, such as the color fade easily or the chrome layer peels off. The anodizing method becomes a potential method to improve coloring techniques because this process is able to provide a protective layer and improve surface appearance through staining and can change the aluminum surface to aluminum oxide, high hardness, and corrosion resistance. This study aims to analyze the surface condition of the aluminum after the anodizing process with several variables. In this research uses the variation of H2SO4 electrolyte solution concentration and electric current as variables to improve aluminum surface quality. Anodizing process is carried out with electrolyte concentration up to 20% and current up to 5 A. The Characteristic of an aluminum oxide layer is tested using hardness test, optical and Scanning Electron Microscope to observe the hardness, the pores distribution and the average of pores diameter. The results of the hardness show that increasing electric current will decrease the hardness of the Aluminum surface. The significant results are also showed in electrolyte concentration variables, increasing electrolyte concentration will reduce hardness and enlarge pores diameter.
Heat transfer analysis of iron ore spherical pellet in the direct reduction process
Authors: Milandia A , Juniarsih A , Muadz R , Sactianto A 
Published: November 2019

Abstract
The aim of iron ore direct reduction process is to convert iron oxide into metallic iron. The conversion of iron oxide into metallic iron occurs through saveral stages of intermediate phase. This intermediate phase included of hematite, magnetite and wustite. Temperatures is one of the important variables to ensure the trasformation of the phase completly. Generally in the direct reduction process, iron oxide process should be agglomerated into 1,5 cm – 2 cm in diameter spherical or cylindrical pellet. Agglomerates form, caused unevan temperatur distibutions within pellet inside. The objectives of this work is to observed energy and the rate of heat flux during reduction process so that intermadiate phase can be trasformed perfectly into metallic iron. To analize temperatur pellet inside, Ansys software was utilized to simulated iron ore direct reduction process. This simulation using agglomerate spherical form. Temperatures simulation take place at 900 into 1100 Celcius for 30 and 69 minute. This simulation also simulated carbon monoxide (CO) as reduction gas at 1 atm
Synthesis and Characterization of Zeolite Lynde Type A (LTA): Effect of Aging Time
Authors: Ginting S B , Yulia Y , Wardono H , Darmansyah  , Hanif M , Iryani D A 
Published: November 2019

Abstract
Zeolite Lynde Type A (LTA) has been widely applied, such as adsorbent, catalyst, membrane, ion exchanger, and even molecular sieve. As molecular sieve, the zeolite LTA has high dehydration ability and has a prospect as separation agent such as water removal from the ethanol-water mixture to obtain high purity bioethanol. Furthermore, it can repeatedly be used, lower energy usage, and environmentally friendly. Due to the number of advantages possessed, this research conducted to synthesize the zeolite LTA. The sources of silica and alumina used are from Coal Bottom Ash (CBA), PLTU Tarahan, Indonesia. CBA is a waste of coal burning that has not fully utilized. This effect of aging time was examined to obtain the highest percentage of its crystallinity. The results showed that 36 hours aging gave a product of zeolite with the best characteristics. The XRD analysis reported that this zeolite had 89.43% of crystallinity. The FTIR identification showed the presence of double rings structure which is characteristic of zeolite LTA. Finally, the result of SEM expressed the morphology of zeolite A on 3.163 μm of crystal size.
Bioplastics synthesis based on sorghum–Eucheuma spinosum modified with sorghum stalk powder
Authors: Darni Y , Sumartini S , Lismeri L , Hanif M , Lesmana D 
Published: November 2019

AbstractIn this study, a bioplastic was produced by addition of filler and plasticizer. Sorghum stalk powder was selected as a filler and glycerol as plasticizer. The effects of filler and plasticizer concentration on physical and mechanical characteristics of the bioplastics were observed. In the bioplastic production, the amount of sorghum stalk powder varied from 0.25 to 1 g, and glycerol concentration was varied from 5 to 20%. On the other hand, the amount ofEucheuma spinosum, as a fiber, and sorghum starch as a matrix remained constant. The bioplastic production has conducted by stirring the starch, fiber, filler, and glycerol for 35 minutes at 95°C and 375 rpm. The mixture was dried at 50°C for 8 hours. The best physical and mechanical characteristics of the product were obtained from the formulation consisting 0.5 g of filler and 10% of plasticizer concentration. The bioplastic itself had 21.265 MPa of tensile strength, 4.467% of elongation, 498.463 MPa of Young’s Modulus, 0.95 g/cm3of density, and 21.265% of water uptake which are in the range of commercial HDPE plastic characteristics.
The Study of the Effect of Final Tin Slag as Partial Substitution in Portland based Concrete towards Corrosion Resistance of Reinforcement Steel against Chloride Environment with Linear Polarization Method
Authors: Aryani Irma T. , Riastuti Rini , Ibnu Muhammad , Shidqi Afif 
Published: November 2019

Abstract
The final tin slag is the final product of the tin smelting process which contains oxide compounds such as SiO2, CaO, Al2O3, and Fe2O3 which have similarities to the content of the oxide compounds found in Portland cement (OPC). The existence of the final tin slag has not been widely used. For that reason, the final tin slag will be very useful if it is used as a cement substitute as a raw material for making concrete. This study aims to analyze the resistance of cement and steel reinforcement mixtures on concrete to a corrosive environment using linear polarization method. In this study, the composition of the final tin slag used was 10%, 20%, 30%, and 40%. The final tin slag used came from PT. Timah Tbk on Bangka Island Indonesia. Then, the 0.5 w/c ratio concrete will be cured for 28 days and will be immersed with a 3.5% NaCl solution for 6 days. The results presented that the reinforcement steel embedded in concrete OPC60-FTS40 was the sufferest towards corrosion since it had the highest corrosion rate in each immersion day among all the concrete samples and followed by OPC80-FTS20, OPC70-FTS30, OPC100, and OPC90-FTS10 in six days of immersion.
The Influence of Yttrium Addition on The Corrosion Resistance and Tensile Strength of as-Cast Mg-Y Alloys
Authors: Setiawan Asep Ridwan , Ardiyana Herdi , Basuki Arif , Wibowo Untung Ari 
Published: November 2019

Abstract
This study shows the effect of Yttrium addition (2-6 wt%) on the mechanical properties and the corrosion resistance of Mg-Y binary fabricated from sacrificial magnesium anode. The beneficial of Mg anode source was tremendous for magnesium alloy especially for corrosion resistance. Improvement of mechanical properties due to the addition of Yttrium was caused by grain refinement solid solution strengthening. Tensile strength increased with the addition of Yttrium. Mg-Y binary is immersed in the SBF solution to see the corrosion resistance. The hydrogen evolution was increased from 0,32 mL/cm2 day, 1 mL/cm2 day, and 34,42 mL/cm2 day for Mg-2%wt Y, Mg-4%wt Y, and Mg-6%wt Y respectively.
Magnetization Dynamic Analysis of Square Model CoFe and CoFeB Ferromagnetic Materials Using Micromagnetic Simulation
Authors: Mustaghfiroh Qoimatul , Kurniawan Candra , Djuhana Dede 
Published: November 2019

Abstract
In this study, dynamic magnetization of square model CoFe and CoFeB ferromagnetic materials were observed using micromagnetic simulation based on LLG equation. The geometrical side size was varied from 50 to 500 nm with the thickness of 5 nm and 10 nm. For simulation process, the used damping factor was 0.05 and the cell size of 2.5×2.5×2.5 nm3 was used with respect to exchange length of CoFe and CoFeB. The external magnetic fields were applied in in-plane and out-plane direction to generate magnetic hysteresis loop. It is found that the coercivity decreased as square size increased for both in-plane and out-plane magnetization direction. The coercivity were around 40 to 200 mT for in-plane field magnetization of CoFe. The coercivity tends to constant at 40 mT in diameter less than 100 nm and zero coercivity for diameter greater than 100 nm for out-plane field magnetization. Compared to CoFe, the coercivity in out-plane field is higher than in-plane field in CoFeB square. It is also observed that the switching time and nucleation field increased as the size increased in out-plane direction of both CoFe and CoFeB. The results showed that the different characteristics of magnetic anisotropy of both materials are important in the development of high density magnetic storage.
Investigation of Dynamic Magnetization in FePt and FePd Disk Ferromagnets Using Micromagnetic Simulation
Authors: Fadhilah Ummaira , Kurniawan Candra , Djuhana Dede 
Published: November 2019

Abstract
In this study, we have observed the magnetic hysteresis loop of the highly anisotropic ferromagnetic materials FePt and FePd with disk model by micromagnetic simulation method based on the Landau-Lifshitz-Gilbert (LLG) equation. We used disk shaped model with varied size from 50 to 500 nm, thicknesses of 5 and 10 nm, and damping constant α = 0.05. The cell size of 2.5 × 2.5 × 2.5 nm3 was used and the in-plane and out-plane fields were applied to the materials. The results showed that the hysteresis loop has a large coercivity when the external in-plane field and close to zero when the external out-of-plane field was applied. This characteristic was similar as typical of the material’s hysteresis loops given the field toward the hard-axis. However, coercivity still observed in materials with size below ≤ 100 nm with ranging values between 20 and 80 mT. From the results, a certain value of the coercivity field appeared in out-plane applied field indicated a perpendicular magnetic anisotropy (PMA) behaviour in FePt and FePd ferromagnets. Moreover, the nucleation field was shifted as the material’s size varied. The results showed that the size affected the magnetic properties of the FePt and FePd thin layers.
The Effect of Thermo Reactive Diffusion (TRD) Processing Time with Ferrochromium Powder on Carbide Layer Characteristics on SUJ 2 Tool Steel Substrate
Authors: Maulida Annida Jihan , Ariati Myrna 
Published: November 2019

Abstract
In this study, the formation of chromium carbide layer on SUJ 2 tool steel substrate as a surface treatment by thermo reactive diffusion process with pack cementation method was observed. The powder used are Al2O3, NH4CL, and FeCr as carbide forming elements with the composition of 37%, 3%, 60% for each. TRD process performed in rotating vacuum furnace for 4, 6, and 8 hours on 980°C. The results show time variation effects on the carbide layer. Thickenss carbide layer on SUJ2 after TRD process observed by Optical Microscope. The morphology of carbide layer observed with SEM shows a smooth and dense layer with almost no porosity formed. Cr23C6 and Cr7C3 found on the layer by XRD and hardness value obtained using Vickers microhardness testing for each samples are 1738.62, 1738.72, and 1739.64 HV. The wear rates are inversely proportional with the hardness value where the values are 0.000698, 0.000658, and 0.000627 mm3/m.
The Effect of Neodymium on the Solidification Process of Al-5Zn-0,5Cu Alloy Sacrificial Anode
Authors: Pratesa Yudha , Iqbal Adimas Habib , Ferdian Deni 
Published: November 2019

Abstract
The effect of the addition of neodymium rare earth on Al-5Zn-0.5Cu alloy was investigated with Optical Microscope (OM), Differential Scanning Calorimetry (DSC), and Cyclic Polarization. The content variable of neodymium tested was 0.1wt%, 0.3wt%, dan 0.5wt%. Observation with OM was conducted to see the changes of the SDAS and the precipitate formation. DSC was used to identify the phase transformation and solidification process of the intermetallic phase. Cyclic Polarization was used to know the corrosion characteristics of Al-5Zn-0.5Cu-xNd. The presence of neodymium formed precipitates on the grain boundary which made shorter SDAS. Addition of neodymium as an alloying element of Al-5Zn-0.5Cu sacrificial anode may decrease pitting corrosion resistance and reduce the size of the loop. This behavior will be more preferable for Al Anode because the indication of more uniform attack.
Characteristics of Products of Thermo Reactive Deposition Surface Treatment on JIS-SUJ2 Steel using Fe-Cr Coating Powder with Process Temperature Variation
Authors: Wiguna Muhammad Panji , Myrna Ariati  
Published: November 2019

Abstract
In this study the effect of temperature variation of the thermo-reactive deposition (TRD) process on carbide layer formation on SUJ2 steel substrates by pack cementation using Ferrochromium powder as carbide former was studied. This process was carried out on SUJ2 steel substrates at temperatures of 900, 980 and 1060 °C for 6 hours. The effect of temperature on layer thickness, homogenity and hardness was studied. Results show that the higher the temperature the thicker the layer formed on the substrate surfaces. Furthermore the XRD results show that the layer formed by this process is chromium carbide. The average microhardness of the layer for 3 process temperature variations is around 1750 HV while the wear rate is around 7 x 10−4 mm3/m.
Effect of Sodium Carbonate on the Reduction Process of Nickel Slag from Sulawesi
Authors: Setyabrata Arum Cahyanurani , Maksum Ahmad , Prasetyo Agus Budi , Priyono Bambang , Wahyuadi Soedarsono Johny 
Published: November 2019

Abstract
Nickel slag is one of the results of the nickel ore smelting process which is still a waste and has not been used optimally. Considering the amount of nickel slag waste in Indonesia, the effort to utilize it into a more valuable product becomes very important. Therefore, in order to extract the precious metal content in nickel slag, this study aims to analyze the effect of adding sodium carbonate in the reduction process of nickel slag. In this study, the reduction process is carried out using coal as a reducing agent, where the variation of the reduction temperature is 800, 900, and 1000°C; while the variation of the ratio between nickel slag and additives is 1:1, 1:2, and 2:1. The XRD analysis results show that the temperature rise up to 1000 °C and the addition of sodium carbonate will increase the amount of sodium magnesiosilicate up to 29.4% and also hematite up to 25.1%. The same thing happened in samples with a ratio of 1:1 and 1:2 where the amount of sodium magnesiosilicate increased from 29.4% to 30.0% and hematite from 25.1% to 28.8%.
Effect of Sn-addition on the properties of the biomedical Ti-17Nb-6Ta alloy.
Authors: Keshtta Alaa , Gepreel Mohamed A.-H 
Published: November 2019

Abstract
The effect of Sn-addition (0, 1.5, and 3 Sn, at.%) to the biomedical Ti-17Nb-6Ta alloy has been investigated in this study. The three alloys were proved using XRD analysis to be β-type alloys. Microstructural analysis using optical microscope showed martensite lathes in all alloys and proved that Sn addition stabilized β phase and suppresses the martensite formation during quenching. Micro-hardness results showed a slight increase with 1.5% Sn adding but superior addition of Sn with 3% at. has negligible effect on the hardness compared to Sn-free alloy. The compressive yield stress for the three alloys located between 400 to 500 MPa, and the stain values increased with the increasing of Sn percentages in the TNT alloy.
Aerogel Based High Performance Thermal Insulation Materials
Authors: Venkataraman Mohanapriya , Mishra Rajesh , Militky Jiri , Kremenakova Dana , Michal Petru 
Published: November 2019

Abstract
In this paper, the thermal properties of polyester/polyethylene nonwoven thermal wraps of varying thicknesses treated with aerogel were analyzed and compared. The microscopic images were taken by confocal microscope and image analysis to compare the physical structure of the aerogel treated nonwoven fabrics. Thermal conductivity and thermal resistance were measured using FOX heat flow meter instrument. The water vapor resistance and thermal resistance were measured using sweating guarded hot plate (SGHP). These tests were conducted to understand and to compare the thermal properties and water vapor resistance of aerogel treated nonwoven fabrics. The results of the experiments were statistically analyzed and showed that the fabric density and the aerogel present in the fabric have a significant effect on thermal properties and water vapor resistance of the aerogel treated nonwoven fabrics.
Wood Plastic Composites from Waste Plastic Bags: Formula Optimization Using Extreme Vertices Mixture Design
Authors: Swasono Y A , Adhyati L , Ujianto O , Ramadhoni B , Wuryanti W 
Published: November 2019

Abstract
Waste plastic bags (WPB) from high density polyethylene (HDPE) have been reprocessed for many applications. However, it is limited to be used as wood plastic composites (WPC) for building applications as the decrease of mechanical properties. This research examined the optimal composition of WPB that can be added to WPC and complied with Indonesian Standard (SNI) 8154 – 2015. Samples were produced according to extreme vertices mixture design using twin screw extruder (TSE). The materials were WPB bounded in the range of 0 to 20 wt%, sawdust at 50 to 70 wt%, neat HDPE at 30 to 50 wt%, and HDPE grafting maleic anhydride (PE-g-MA) at 0 to 10 wt%. The compositions were optimized to obtain desired flexural modulus and strength as required on SNI standard. The optimized formula was then reproduced and characterized to analyze its water content, density, swelling, and formaldehyde content. The results showed that the optimum formula was predicted at 3 wt% of WPB, 50 wt% of sawdust, 37 wt% of neat HDPE, and 10 wt% of PE-g-MA, giving 2111 MPa and 27.3 MPa of predicted values that above the minimum requirement for WPC material (2000 MPa for modulus, 20 MPa for strength). Meanwhile, the modulus and strength of verification sample were 2173 MPa and 25.7 MPa. Further analysis on the other properties showed 0.6 ± 0.1% of water content, 1.7 ± 1.4% of swelling, and 0.015 ± 0.000 mg/L of formaldehyde that lower than maximum specifications, and 1.13 ± 0.01 g/cm3 of density that above minimum the requirement.
Improving Performance of LiFePO4by addition of Carbon Nano Tube for Lithium Ion Battery
Authors: Honggowiranto W , Kartini E , Sudaryanto  , Rofika R N S , Hutamaningtyas E , Subhan A , Sudjatno A 
Published: November 2019

AbstractLiFePO4(LFP) cathode material has been synthesized with hydrothermal method. The reaction was done by reacting a mixture of FeSO4.7H2O, H3PO4, LiOH and CNT. In order to improve performance of LFP, the carbon nano tube (CNT) was added with the variation of 5, 10 and 15 mmol, before hydrothermal process. The material was stirred using a magnetic stirrer for 30 minutes, and then autoclave was heated at 180°C for 6 hours then sintered at 700°C for 6 hours. The results were characterized by X-ray diffraction (XRD), and Scanning Electron Microscope (SEM), and Impedance Spectroscopy (EIS). The X-ray data shows that the crystal structure of synthesized LiFePO4has a group of Pmn with a space (olivine structure) which is in agreement with the LFP standard material. The addition of CNT does not change the crystal structure. This shows in SEM images that the crystallite size of LiFePO4particles does not have much effect on the composite. The battery cell performance was measured by Impedance Spectroscopy and charge/discharge Battery Analyzer BST-8. The EIS data, showed the decreasing of battery impedance total from LiFePO4material without CNT to addition of 5, 10 and 15 mmol CNT namely 214; 128.1; 88.6 and 70.1 Ω, and the specific capacity 0.1C are 38.78; 51.53; 106.84; 92.79 mAh/g, respectively. It is shown that the maximum specific capacity was obtained for LFP composite with the addition of 10mmol CNT. It can be concluded that the addition of CNT increases the conductivity and specific capacity, thus improving performance of lithium ion battery.