bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of NTC thermistors with screen printing method from natural yarosite minerals
Authors: Aningratri Iga Purwitasari , Nazriati Nazriati , Syarif Dani Gustaman 
Published: February 2021

Abstract
NTC thermistors can make from a mixture of metal oxides. Fe2O3 is a metal oxide contained up to 93.80% in the natural yarosite mineral and has the potential to be used as a material for making thermistors. The objective of this research is to use Fe2O3 from yarosite and Fe2O3 from imports in the production of NTC thermistor and to determine the effect of adding ZrO2 to a mixture of Fe2O3 from yarosite, ZnO and CuO in the manufacture of thick-film oxide ceramic NTC thermistors. Oxide ceramic powder is synthesized, using the sol-gel method. Furthermore, oxide ceramic powder was made into thick-film oxide ceramics made by screen printing technique with a sintering temperature of 1100°C for 2 hours, then characterized using XRD and SEM. After a thick-film oxide ceramic was coated, with silver paste, an NTC thermistor was obtained and measured its electrical resistance to temperature using a multimeter and temperature controller. The results of the analysis of XRD characterization reveal that the crystal system of the ceramic mixture from the samples was rhombohedral. Based on the results of SEM analysis, the addition of ZrO2 doping showed a change in grain size to be smaller. NTC thermistors with raw materials Fe2O3 from yarosite, ZnO, and CuO (Sample I) have resistance which decreases with increasing temperature according to the characteristics of NTC thermistors and has better electrical characteristic than Fe2O3 from imports, ZnO, and CuO (Sample III) for NTC thermistor applications that are preferred commercially. The addition of ZrO2 doping (Sample II) increases the resistance.
Physicochemical characteristics and electrical conductivity of bismuth oxide/activated carbon composite
Authors: Astuti Yayuk , Widiyandari Hendri , Zaqia Faradina A. , Annisa Lifiany , Fajarwati Roshana M. , Hartinah Siti 
Published: February 2021

Abstract
Bismuth oxide/activated carbon composite was prepared from precursors of bismuth nitrate pentahydrate and activated carbon. At first, the Bi(NO3)3 solution was mixed with activated carbon. The activated carbon used varies, namely commercial activated carbon and activated carbon derived from rice husk. The resulting mixtures were then heated into a hydrothermal reactor at a temperature of 110°C for 5 hours. The results obtained were then characterized using FTIR, XRD and LCR meter. The results showed that Bi-O and Bi-O-Bi functional groups and α-Bi2O3 had appeared in both products indicating bismuth oxide had been formed. Meanwhile, the results of electrical conductivity characterization for bismuth oxide/rice husk activated carbon composite is higher than bismuth oxide/commercial activated carbon composites. In the future, bismuth oxide/activated carbon composites can be applied as materials for producing battery electrodes; however, further research must be undertaken.
An overview on antibiofouling agent from carica seeds waste as antifoulant coating
Authors: Sari Ni Kadek Adnya Kusuma , Arrois Sadam , Gunawan Tiara Amelia , Ariyanti Dessy 
Published: February 2021

Abstract
TBT (Tributyltin) is used to prevent biofouling, but it causes a dangerous effect on other marine biodiversity. In Wonosobo Regency, there are lots of Carica seeds (9 tons/month) which not utilized and considered as wastes. Whereas Carica seeds contain active compounds (saponins, alkaloids, phenols, flavonoids, and tannins) which are classified as antibacterial agent. Antibacterial compounds are used to prevent the formation of biofilms (which cause biofouling). This article discusses the antibacterial activity of Carica seeds and its prospects as an antifoulant coating. The general mechanism of the inhibition of the biofilm formation featuring bacteria were explained as sequences as follow (1) inhibiting cell division, (2) inhibiting DNA and RNA synthesis and (3) damaging cell membranes. By the number of antibacterial components contained in Carica seed, it has the potential to be used as an antifoulant coating because of its antibacterial and antibiofilm activity. However, further research needs to be done regarding the effective composition of the Carica seed waste and coating materials (binders, pigments, solvents, and additives) and their characteristics.
Synthesis of 131I Iopamidol as a Tracer for Development of Iopamidol CT-Scan Contrast Agent
Authors: Widjaksana W , Rezka Putra A , Juliyanto S , Khoirunnisa  , Hanifah B 
Published: February 2021

Abstract
Computed Tomography (CT) Scan is a means of imaging/diagnostic method which is preferable in hospitals in terms of availability, efficiency and cost. Currently, CT contrast agent most widely used is the iodinated derivatives, due to its high X-ray absorption coefficient. Contrast agent is a medical preparation used in CT-scan modality which has capability of enhancing the performance of CT-scan to differentiate between target organs and surrounding tissues, and one of them is iopamidol. Development of iopamidol contrast agent requires several steps, i.e formulation, characterization, in-vitro and in-vivo tests prior to clinical study. To do in vivo study or biodistribution study in experimental animals, a radioactive iopamidol should be used to trace the compound throughout the body to predict its pharmacokinetics, and for that purpose a radioiodine (Iodium-131 or 131I) labeled iopamidol will be used. Optimation in the synthesis of 131I iopamidol was carried out by varying pH, temperature and reaction time to obtain 131I iopamidol with high radiochemical purity of more than 90% as a requirement of radiopharmaceutical preparation. The radiolabeled product was characterized using HPLC and the labeling efficiency was measured by TLC. The optimum condition obtained was repeated 3 times and the product was tested for stability in room temperature. Characterization using HPLC showed that retention time (Rt) of radiolabeled iopamidol was close to that of native iopamidol at ∼ 6 min, indicating that 131I iopamidol was already formed. Iodium-131 labeled iopamidol has been successfully synthesized with labeling efficiency or radiochemical purity of 96% ± 1%, and the optimum condition of 131I iopamidol reaction was obtained at pH 9, temperature of 140°C in 5 minutes reaction time, and the product was stable in room temperature up to 7 days. It is concluded that radioiodinated iopamidol has been successfully synthesized and will be used in the formulation of iopamidol as a part of iopamidol contrast agent development for CT-Scan purpose.
Lactic Acid Fermentation from Durian Seeds (Durio zibethinus Murr.) Using Lactobacillus plantarum
Authors: Abdullah Abdullah , Winaningsih Ima , Hadiyarto Agus 
Published: February 2021

Abstract
Durian is one of the abundant seasonal fruits at harvest time. Generally, the part consumed in durian is its salute fruit or its meat. Durian seeds contain 70-80% carbohydrates, but not yet utilized. Carbohydrates can be fermented into lactic acid using Lactobacillus plantarum bacteria. Lactic acid is a raw material for biodegradable plastic/poly lactic acid (PLA). The purposes of this study were to determine the effect of substrate concentration (7.5%, 10%, 12.5%, 15% and 17.5%), inoculum concentration (2%, 5%, 7%, 10% and 12%), and yeast extract concentration ( 0 g/L, 2.5 g/L, 5 g/L, 7.5 g/L and 10 g/L) on the yield and the concentration of lactic acid produced. The research was initialized by making durian seed flour, testing the proximate value of the materials, bacterial inoculation, fermentation of durian seed flour at 37°C, agitation speed of 100 rpm for 72 hours, then the fermentation results were analyzed for lactic acid concentration using UPLC (Ultra Performance Liquid Chromatography). The highest yield and lactic acid concentration at substrate concentration of 15% were 12.51% and 13.75g/L, at inoculum concentration of 2% were 19.44% and 21.3 8g/L, while the highest yield and lactic acid concentration at 10 g/L yeast extract concentration were 21.76% % and 23.92 g/L.
Optimization of Lactic Acid Fermentation from Durian Seeds (Durio zibethinus Murr.) Using Response Surface Method
Authors: Abdullah Abdullah , Winaningsih Ima , Hadiyarto Agus 
Published: February 2021

Abstract
Lactic acid production in Indonesia has not been able to meet the needs of the industry, especially as the raw material for biodegradable plastic/poly lactic acid (PLA), thus an inexpensive and abundant alternative material is needed, based on previous research, durian seed waste has the potential as a raw material to produce lactic acid by fermentation using Lactobacillus Plantarum bacteria, but there is no optimization yet. This study aimed to determine the optimization mathematical modeling of the variables that affected yield and concentration of lactic acid, namely substrate concentration (15%), inoculum concentration (2%), and yeast extract concentration (10 g/L), using the Response Surface Method (RSM) and Central Composite Design (CCD) to save time and costs. This research was conducted in several stages, preparation of raw materials, testing the proximate value of the materials, inoculation and rejuvenation of bacteria, fermentation at 37°C, agitation speed of 100 rpm for 72 hours, then the fermentation results were analyzed using UPLC (Ultra Performance Liquid Chromatography) for its lactic acid concentration. Response Surface Method (RSM) was executed by using software Minitab 17. The obtained mathematical equation model for the fermentation reaction of lactic acid production was Y = 22.49 + 1.883X1 + 1.305X2 + 1.380X3 - 3.273X1*X1 - 2.558X2*X2 - 1.475X3*X3 - 0.968X1*X2 + 0.390X1*X3 + 0.954X2*X3 with the optimum conditions for substrate concentration, inoculum concentration, and yeast extract concentration respectively of 15.14%, 2.16% and 10.3 g/L.
A Comparison of the Bioethanol Production from Suweg (Amorphophallus campanulatus) through Separate Hydrolysis and Fermentation as well as Simultaneous Saccharification and Fermentation Using Saccharomyces cerevisiae
Authors: Hargono H , Jos B , Purwanto P , Sumardiono S , Zakaria MF 
Published: February 2021

Abstract

Suweg has the potential to develop bioethanol because of the high starch content. This is a form of ethanol produced from living organisms. The processes used include separate hydrolysis and fermentation (SHF) as well as simultaneous saccharification and fermentation (SSF). Furthermore, the components utilised in this study include StargenTM 002 (1.5%, w/w) for hydrolysis, Saccharomyces cerevisiae for fermentation at a temperature, and PH of 30ºC and 4.5 respectively, with varying starch concentrations (150-250 gL−1). The results showed the highest ethanol yield of 89.57 and 99.52 gL−1 from SHF and SSF, respectively from a suweg concentration of 200 gL−1 treated for 54 h. Meanwhile, 250 gL−1 samples attained 62.22; 99.57; and 101.56 gL−1, respectively. Therefore, SSF method provided a more efficient process for producing bioethanol using the 250 gL−1 concentration, although the increase from 200 gL−1 to 250 gL−1 only produced a 1.96% higher yield.
Garcinia mangostana L. fruit rind extract in ethyl acetate, n- butanol and water fractions: phytochemical analysis, antioxidant assay and cytotoxicity assay
Authors: Krisanti Elsa Anisa , Farizal Ashri Nadhira , Mulia Kamarza 
Published: February 2021

Abstract
The aim of the study is to investigate the relationship between the phytochemical content of the fruit rind of Garcinia mangostana Linn with antioxidant activity and cytotoxicity of different fractions (ethyl acetate, n-butanol, water) of the xanthones extract. The ethyl acetate fraction showed the highest total xanthones as quercetin equivalent and &#x03B1;-mangostin equivalent, total xanthones as a-mangostin, and, total polyphenol content. High antioxidant activity and cytotoxicity were also shown from the ethyl acetate fraction with 55.8 μg/ml and 0.0029 μg/ml for IC50 and LC50 values, respectively. The linear correlations were confirmed between the total phenolic content and antioxidant activity as well as cytotoxicity of the xanthones extracts. The results of bioactivity assays and photochemical analysis of different fractions of xanthones extract showed that the ethyl acetate fraction of xanthones extract can be considered as a promising source of anticancer bioactives to be used in controlled release formulations.
Consistency of batch anaerobic digestion process of high and low activated sludge concentrations to the interference of sodium benzoate as preservative material
Authors: Sumantri I , Murdiyono  
Published: February 2021

Abstract
Anaerobic digestion resulted best performance in degradation of organic materials. Degradation of the organic materials was stated as complete by the formation of methane, carbon dioxide etc. (or biogas) as the final product of degradation. Food or beverages products utilized preservative agents in order to prolong the expired date. Sodium benzoate is the most common of preservative agent which can be used for both food and beverages. This experiments were pointed out to observe the effect of high and low activated sludge to the formation of biogas. Research was conducted in some batch mode reactor systems employing high and low of activated sludge (80% and 20% of volume) and solution concentration of sodium benzoate volume. The activated sludge used was 12 g MLSS/L. Concentrations of sodium benzoate used were 400, 600, and 800 mg/L. Product of biogas samples was measured every two days for 60 days of experiment. The results showed that the volume ratio of activated sludge and sodium benzoate of 80% able to reduce the interference of sodium benzoate and for 20% was not able to produce biogas where the load of sodium benzoate influenced the production of biogas.
Alginate Modification for Stabilizing Fish Oil Emulsion
Authors: Wardhani D H , Ulya H N , Kumoro A C , Aryanti N 
Published: February 2021

Abstract
Alginate has been widely used in food industries, including for encapsulant of active agent preservation. This polysaccharide is highly hydrophilic and had been studied as an excellent material for encapsulating water-soluble substances. Fish oil which mainly contained omega-3, provides many health benefits including for reducing the effects of hearth and mental disorder. Regardless fish oil’s goodness, its taste and aroma become an obstacle in direct consumption. Encapsulation is one method to mask these problems. However, different hydrophilicity has been repelled the use of alginate as fish oil excipient. Succesful encapsulation requires a stable emulsion between alginate and fish oil. Hence, alginate should be modified to improve its hydrophobic properties. This study was aimed to investigate the effectiveness of the modified alginate using stearic acid on stabilizing fish oil emulsion. Effect of heating treatment on alginate modification was conducted. The infrared spectra confirmed the alteration of alginate functional groups. The modified alginate improved stabilization of fish oil emulsion up to 100 min at room temperature. This study revealed the possibility to modify the hydrophobic functional group on alginate using stearic acid to upgrade its emulsification ability.
Role of The Concentration of Fe/C Catalysts on Heterogeneous Fenton Degradation Remazol Yellow FG
Authors: Amelia Shinta , Muflikhah R. Septiani , Ustinah  
Published: February 2021

Abstract
Remazol Yellow FG is a thiazine dye widely used in textile industries. This compound is difficult to degrade naturally. One method that can be used for wastewater treatment is the Advanced Oxidation Process with heterogeneous Fenton reaction. The heterogeneous Fenton reaction mechanism uses H2O2 as an oxidizer and iron nanoparticles as a catalyst. One material that can be used as catalyst support for iron nanoparticles is activated carbon. Activated carbon can be modified as a catalyst support because it has a large surface area. Iron oxide (Fe2O3) is embedded in activated carbon through the process of impregnation and calcination at a temperature of 300°C. Fe2O3 loading varies 2%, 4%, and 6% of the total carbon mass. Fe/C catalysts were characterized by SEM and BET-BJH. The catalytic degradation reaction of Remazol Yellow FG was carried out by dissolving 200ml of Remazol Yellow FG at a concentration of 20ppm and adding 5ml of H2O2.The degradation results using 96 hours Fe/C catalyst for variations of concentration were analyzed using a UV-VIS spectrophotometer. Then the measurement of degradation for Fe2O3 concentration of 2%, 4%, 6% using the heterogeneous Fenton method resulted in the percent removal of 16.82%, 40.46%, 38.32%. Whereas using physical adsorption on each variable Fe2O3 concentration did not result in percent removal. Data shows that the degradation capacity of Remazol Yellow FG using heterogeneous Fenton reaction increases with increasing Fe2O3 concentration. This also proves that the heterogeneous Fenton method using the Fe/C catalyst is effective for the degradation of Remazol Yellow FG.
Kinetic Study of Glycerol Monolaurate (GML) Production from Glycerol with Lauric Acid Using a Dealuminated Zeolite Y Catalyst
Authors: Oktavianty H , Sasongko S B , Buchori L , Anggoro D D 
Published: February 2021

Abstract
This study aims is to study the ability of zeolite Y to produced higher yield of glycerol monolaurate. This study focused on dealumination zeolite synthesis Y applied on glycerol monolaurate synthesis and kinetic study of glycerol monolaurate synthesis. The stages of this research consisted of zeolite Y catalyst dealumination, synthesis of glycerol monolaurate and acid-base analysis of catalyst. The esterification process was carried out with 1: 7.5 mole ratio of reactant (glycerol/lauric acid) at 1300C and a stirring speed of 300 rpm. Data obtained from the experimental results show that the longer the time used, the greater the ability of the zeolite Y to synthesize the glycerol monolaurate. The esterification process was carried out by using 2nd order rate equation with R2 about 0,9051 with ratio of the first reactant CA0≠CB0. The determination of k value was expressed by equation

l
n

M
−
X
A

M

(

1
−
X
A

)

=

(

C

B
O

−

C

A
O

)

k
t

. Constant reaction rate value of glycerol monolaurate is 0,006805 L/mol.min.
PHENOL WASTE TREATMENT USING OZONE-PLASMA HYBRID REACTOR
Authors: Luvita Veny , Bismo Setijo , Sugiarto Anto Tri 
Published: February 2021

Abstract
Phenol is one of the most dangerous ingredients in industrial wastewater, which has acute toxicity and is difficult to degrade in the environment. Therefore, Ozone-Plasma Hybrid Reactor (RHOP) is an effective phenol waste treatment used to test the performance of the treatment of synthetic phenolic compounds. Its working principle is based on the combination of ozonation reaction in the liquid plasma field of the reactor. Ozone as a reagent is produced by the ozonator, which is fed into the RHOP by mixing it with the liquid phase feed in the injector to enable the intensive the reaction of the two-phase mixture react. Furthermore, the two-phase mixture intensifies hydroxyl radicals when the liquid phase is in alkaline condition and continuously exposed in plasma. The results obtained from the performance test carried out on several wastes with high concentrations, showed that the system needed improvement. The improvements were made by changing the reactor system to Dielectric Barrier Discharge (DBD) plasma with wire cylinder configuration, to degrade synthetic waste containing phenolic compounds through active species formed in the reactor. This process has a high oxidation potential and decomposes various organic pollutants in waste. Furthermore, the ozonation technique was applied to the DBD reactor with the aim of increasing the amount of ozone and OH• radicals, therefore maximizing the phenol degradation process.
Concrete Brick Production Using a Mixture of Paint Waste by Solidification Process
Authors: Purwanto P , Sudarno S , Citra A D P 
Published: February 2021

Abstract
Unutilized hazardous and toxic waste requires management and landfill costs. Hazardous and toxic paint waste can be used as additional raw material to make brick products through solidification. Concrete bricks are made from a mixture of cement (1 part) and sand (14 parts) with the addition of water for mixing purpose. The mixture composition is 0,1,2,4,6, and 8% by using paint waste as the raw material added. Then, the quality of concrete brick products is tested on compressive strength and water permeability. The test results can be used as recommendations for the use of paint waste into products and reduce waste management costs.
Review on hazard analysis and critical control point (HACCP) in the dairy product: Cheese
Authors: Suherman S , Janitra A A , Budhiary K N S , Pratiwi W Z , Idris F A 
Published: February 2021

Abstract
Hazard Analysis Critical Control Point (HACCP) is a control system in the effort to prevent problems that are based on the identification of critical points in the handling and production stages. HACCP is a form of risk management that was created to guarantee food safety with a preventive methodology which is considered to provide guarantees in producing food that is safe for consumers. The purpose of this study was to determine the application and effectiveness of HACCP from fresh milk and its derivative products in the form of cheese at PT. G, so that a system that is truly capable of guaranteeing the product is produced. In the milk production process there are many aspects that need to be considered, starting from the initial stage of quality control of raw materials to the final product of the production process which is then stored in a warehouse. The method used is the elaboration of the Codex Alimentarius Commission in the European Committee for Standardization 2004 Hazard Analysis Critical Control Point (HACCP) system. Based on the analysis of the flow diagram shows that there are critical control points both for microbiological, chemical and physical quality in the process of receiving raw materials (fresh milk) and at the production of critical points.
Development of Natural Gas Hub Network Based on Specific Total Annual Cost in East Java Region
Authors: Ardian Irfan , Rifqi Furtiansyah M. , Anugraha Rendra Panca , Sutikno Juwari Purwo , Handogo Renanto 
Published: February 2021

Abstract
Natural Gas is one of fossil fuel energy with the lowest CO2 emission and has been widely used in Indonesia. However, the absorption of natural gas in Indonesia is still not optimal. Several regions have natural gas supply above the region’s needs and some regions otherwise. The solution to these problems is to create a coordinated gas network in a system that called the hub method. In this method, all producers send their gas to the hub or collection point, then the gas is sent from the hub to consumers. Later a regasification station and LNG plant were connected into the hub. With this method, the problem of excess gas supply and lack of natural gas can be overcome. In this study, the natural gas network was developed by using hub method modelling with the case study in East Java. The first model is the grassroots model which assumes there is no natural gas network in the region. The second model is a combined model that was done by modifying/adding pipelines from existing pipelines. The two models were optimized by minimizing the total annual cost (TAC) needed which includes the cost of making and operating pipes and compressors. From the results obtained, the specific TAC which is the TAC divided by annual gas supply capacity from the grassroots, existing, and combined models are US$ 1.52/MMbtu, US$ 1.50/MMbtu, and US$ 1.44/MMbtu, respectively. Therefore, the combined model is the most optimal based on specific TAC.