bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporary Occupancy Permit ( SLF ) for Building Sustainable Strategy
Authors: Juliardi R D , Puri E R , Aziza M I
Published: April 2021

When both deterioration and obsolete being considered reutilizing, it needed to assess a temporary occupancy for this existing Building. Temporary Occupation Permit as an assessment stage on function properly as building operation. Deterioration and obsolete both are a result of a condition on utilizing for more than 20 years. Hence, as a visual, it has a few decreasing physical values caused by utilization usage. Present, the buildings in Indonesia started to focus on this process. So, how this assessment to be a part of sustainability building, related that matter. Bank Jawa Barat in Jl Naripan, is a case study for this paper. As one of a few multi-stories buildings in Bandung, this Building runs into decreasing quality. Directions of the paper aim at strategy on building sustainable based and methods to take adaptation, certification, and building age aspects into account. These will define temporary occupation, deterioration, and obsolescence related to the current Building of new construction. In this paper, the perspectives of the building sustainability of a whole building are presented, based on state of the art, a study of function properly as building operation on the temporary occupation of life-cycle assessment for buildings. Finally, the Building of Bank Jawa Barat will illustrate to answer all regarding evidence the topic, that occupancy permit is a sustainable building strategy.
Web based development of information system administration
Authors: Suhada S , Amali L N , Takdir R , Pakaya G
Published: April 2021

Mail administration information system is a web-based system that can manage incoming-outgoing mails as well as leave applications. The management and preparation of mails, both incoming and outgoing, are often recorded manually in a journal book. The incoming mail is recorded in general and subsidiary journals, while the outgoing mail is recorded in one journal book only. This mail administration information system offers better document management to prevent any document loss. In designing the system, the study relied on system architecture, context diagrams, data flow diagrams, database modeling and ERD (Entity Relationship Diagrams). The purpose of this study is to create an administrative information system that is capable of managing and archiving mails. The system development employed a prototype method. The development resulted in web-based information systems of document archiving. This application is also expected to help the District Military Command in Gorontalo to manage and archive mails for efficient administration.
Design variations optimization of jib crane 24500 N using I beam 300
Authors: Sirojuddin S , Nurfarihah K Z A , Nurkhozin M
Published: April 2021

A jib crane is a type of lifting equipment that is commonly attached to the walls of factory buildings to raise or lower a load. The lifting mechanism can rotate with a turning angle of 180 degrees. A trolley hoist can be moved manually by chain drive. This research aimed to optimize the design of several variations of the jib crane structure of load lifters that meet the criteria of optimizing safety factor. Firstly, the design concept was made by varying the main beam of the I Beam 300. Then calculated analytically. The 2D and 3D geometry were made in four variants of JC-1, JC-2, JC-3, and JC-4. The strength of the main beam structure and others was analyzed using FEM software. The load of the crane was 24500 N, a range radius of 3 meters, and a turning angle of 180 degrees. The best results were obtained by comparing the yield stress to the maximum stresses that occurred according to Von Mises. Based on the simulation results, the best design is the JC-4 variant. Variant JC-4 simulation results show that the safety factor closed to the optimum point.
The synthesis of magnetic molecularly imprinted polymer against di-(2-ethylhexyl)phthalate
Authors: Rizqi Utami Asyifa , Ali Zulfikar Muhammad , Wahyuningrum Deana
Published: April 2021

Magnetic molecularly imprinted polymer (MMIP) was prepared against di-(2-ethylhexyl)phthalate, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker and benzoyl peroxide as an initiator. MMIP was characterized using Scanning Electron Microscope and infrared spectrophotometer. IR spectrum shows successful preparation of MMIP. The peak at 586 cm−1 is a typical vibration of Fe-O. The strong peaks at 1728 cm−1, 1261 cm−1, and 1153 cm−1 are stretching vibration of C=O and C-O of methacrylic acid and DEHP. The peak at 1462 cm−1 due to C-C aromatic vibration of DEHP. A broad absorption band at 3468 cm−1 due to the stretching vibration of hydroxyl bonds between target molecule and functional monomer. The MMIP has a spherical morphology and pores that important for adsorption process. Experimental results show the potential of magnetic molecularly imprinted polymer for recognition of di-(2-ethylhexyl) phthalate.
Effective Deagglomeration in Biosynthesized Nanoparticles: A Mini Review
Authors: Khairunnisa S , Wonoputri V , Samadhi T W
Published: April 2021

Materials with nanoscale particle size have different properties from its bulk phase, which allows for wider application of the material. There are various methods to synthesize nanoparticles, namely physical, chemical, and biological method. Nowadays, nanoparticle synthesis method is focused on biological method because of its advantages, such as environmentally friendly, relatively simple procedures, and lower production costs. Biosynthesis by co-precipitation method using extracts from biological agents is considered the most efficient among other biological methods. Biochemical compound in the extract have a dual role in synthesis, they act as a reducing agent which reduces metal salt to metal ion, and as a capping agent which stabilizes the nanoparticle. Biosynthesis has been shown to result in nanoparticles as good as physical and chemical method. However, several studies report that the synthesized nanoparticles have low stability regardless of the presence of their capping agent, resulting in agglomeration of nanoparticles, which reduces its efficiency. Until now, studies on particle deagglomeration especially during nanoparticle biosynthesis have not been widely carried out. This mini review will explain the phenomenon of agglomeration during biosynthesis. Moreover, deagglomeration treatment using physical and chemical approaches will be examined. Each approach is considered to be able to deagglomerate nanoparticles well, and the combination of the two is projected to be able to provide better results.
Numerical Investigation of Double Chamber Acetate-Fed Microbial Fuel Cell in Unsteady-State Condition
Authors: Subadri I , Satriyatama A , Budi I D M , Harimawan A
Published: April 2021

Microbial fuel cells (MFCs) are devices that utilize the work of microorganisms to oxidize organic substrate involving biochemical pathways. Several studies have been done based on experiments while simulation and modelling remain unexplored. Basically, MFCs have a lot of similarities to chemical fuel cell systems, which modelling and simulation have been widely developed. Hence, a study should be done to develop the model in order to widen the implementation of MFCs. In order to evaluate MFCs performance with less cost and time, numerical modelling might be an effective approach. Models could also be easily developed or modified for various operation conditions and configurations to generate experimental data on MFCs. A number of papers on simulation and modelling focused on cell voltage as function of both cell current density and chemicals concentration. In this paper, a double chamber acetate MFCs under continuous operation and unsteady state condition would be investigated. MFCs model based are developed by calculating biochemical reactions, Butler-Volmer equation, and electrochemical equations using MATLAB 2018a software. The parameters and constants data reported from recent literature are used. Results show that periodic flow rate of fuel could improve the power production. This result also gives the prediction of cell voltage and current density. Nevertheless, models with various conditions or configurations could be developed to scale-up or create more efficient MFCs using simple methods.
Syngas fermentation for production of ethanol
Authors: Istiqomah N A , Kresnowati M T A P , Setiadi T
Published: April 2021

The global demand for fossil fuels has increased sharply in the past 50 years. Plant biomass is one of the fourth largest non-fossil renewable energy sources after geothermal, solar, and wind energy. Biomass can be first converted into another energy form, such as ethanol, to provide a more efficient energy source. Syngas fermentation enables converting all biomass components, including lignin, into ethanol, thereby increasing the biomass quantity. The development of the syngas fermentation process will be reviewed in this article, which focuses on the types of microorganisms used, the effect of syngas composition, and the gas-liquid mass transfer to be used as a reference for optimizing the syngas fermentation process.
Catalytic Process Development of Bio-BTX from Lignocellulose Derived Product: Preliminary Study Using Transition Metal Catalysts
Authors: Pandu Winoto Haryo , Rasrendra C B , Rizkiana Jenny , Kurniawan Leo Johanes , Citawijaya Andre
Published: April 2021

Lately, the increase in biofuel production has simultaneously led to lignocellulose material disposal activities. As a waste produced by the biofuel industry, lignocellulose materials are not utilized fully yet due to their complex polymeric structure. As one compound of lignocellulose, lignin possesses the lowest economic value due to its recalcitrant nature. In this work, guaiacol as one of monomeric substance originated from lignin is used as a representative molecule to be valorized due to the existence of both hydroxyl and methoxy moiety groups in it. One important reaction of lignin monomeric substance (phenolic compounds) valorization is oxygen removal. Aromatic substances such as Benzene and Toluene are produced through oxygen removal from the guaiacol molecule. Hydrodeoxygenation of guaiacol is aimed to remove oxygen atoms from it. Though conventionally hydrogen for the Hydrodeoxygenation process is supplied by external molecular hydrogen, in this work it is supplied from hydrogen atom abstraction of methylcyclohexane. Therefore, in a one-pot catalytic reaction system, methylcyclohexane dehydrogenation is the sole hydrogen provider for subsequent hydrodeoxygenation of guaiacol and this novel concept of a circular hydrogen economy has been proven its feasibility through heterogeneous catalytic reaction schemes conducted in this work. Metal supported on zeolite beta is selected as heterogeneous catalysts to evaluate the feasibility of one-pot hydrodeoxygenation and dehydrogenation reaction. Of every catalytic reaction attempt, multiple products consist of alkylated phenol, phenol itself, and toluene are observed proofing the feasibility of this concept. Possible interaction of catalyst surface acidity and metal contents are also probed through the distribution of byproducts. Overall, sequential dehydrogenation and hydrodeoxygenation have been proven through a catalytic reaction catalyzed by metal-supported zeolite beta catalyst and this work can potentially pave the way for further application.
Cost-Benefit Analysis of Palm Kernel Shells as a Diesel Fuel Substitution for Hot-Mixed Asphalt
Authors: Gravitiani Evi , Resti Chayyani Nuri , Herwi Pranolo Sunu , Setyono Prabang , Setyawan Ary
Published: April 2021

Indonesia is one of the biggest oil palm producing countries. Solid waste from processing palm oil into crude palm oil (CPO) includes palm shells. This palm shell waste can be used as an alternative to diesel fuel for aggregate heating. This study aims to analyze the investment of the use of palm shells as an asphalt burner replacing diesel. Primary data were obtained from field and laboratory identification. In contrast, secondary data were obtained from relevant agencies, the Department of Public Development and Public Housing, PT Bara Energi Biomass and PT Damai Citra Mandiri. The method used is a quantitative descriptive analysis by calculating the annual costs and benefits over the machine’s life, ten years. This study uses the Cost-Benefit Analysis. Four investment criteria are calculated: (1) Net Present Value (NPV), (2) Benefit-Cost Ratio (BCR), (3) Payback period (PbP), (4) Internal rate of return (IRR). The results found that palm shells’ use as an asphalt burner for diesel substitutes showed high costs and top benefits. The calculation of economic feasibility with investment criteria shows that the NPV has a positive value, which means it is feasible. BCR shows a ratio of costs and benefits is more than one; it indicates that investment in asphalt production activities is feasible. The calculation of investment in replacing diesel fuel with palm shells shows a positive value of PbP since the first year. The internal rate of return shows that the investment value has met the minimum standard of general interest or replacement.
Cogasification performance of deashed coal with various biomass
Authors: Rizkiana Jenny , Fajar Maulana Sandy , Azka Nur Aulia Ghiffary , Kamilah Nasywa , Fitri Ananda Reyhan , Fauzan Mahendraputra Sastrohutomo Naafi , Muhammad Nashirudin Latif Edo , Wulandari Winny , Sasongko Dwiwahju
Published: April 2021

Cogasification of lignite and EPFB is present as a production of energy sources that aim to get a synergy effect. However, not all cogasification gives better product quality than fuel parent gasification. In this study, demineralization acted as lignite pre-treatment stage is achieved through HF leaching at 70°C for 4 hours. The mixing ratio varied by lignite to empty palm fruit bunches (EPFB) are 1: 2, 1: 1, and 2: 1 both for non-demineralized lignite (BLM) and lignite demineralized (BLD). The negative synergy effect of two combination is caused by the high content of silica and alumina from the empty palm fruit bunches (EPFB). The lignite demineralization cogasification produces a lower H2 yield than BLM because it also dissolves the mineral content which functions as a catalyst for cogasification synthesis.
Mass Balance analysis of Bioethanol Production from Sweet Sorghum (Sorghum bicolor)
Authors: Lauda Muhammad , Rahmawati Nadiya , Rahma Putri Fajar Wayda , Ramadhani Aliya , Amirah June Rahmah , Pratiwi Meiti , Rizkiana Jenny
Published: April 2021

Current fossil fuel reserves cannot keep up with the world’s need for fuel, leading to a global energy crisis. The issue raises attention to renewable energy sources. Indonesia has committed to using 15% bioethanol in gasoline mixture by 2025, as outlined in Presidential Decree No. 5 of 2006. This article discusses past studies on sweet sorghum plants in their use as a raw material for bioethanol production from various aspects. The study shows that sweet sorghum juice has a high potential to be converted into bioethanol due to its high sugar content. Pretreated sweet sorghum seeds and bagasse also have great potential to be converted into bioethanol due to their rich oligomer and polymer sugar content. The main challenge of producing bioethanol from sweet sorghum is the low economic competitiveness of utilizing sweet sorghum as an energy crop compared to using sweet sorghum as a food crop. The present study focuses on the mass balance analysis of bioethanol production from sweet sorghum. It is expected that the results of the present study may give a preliminary overview of the bioethanol production potential from sweet sorghum.
Economic and Life Cycle Assessments of Integrating Gasification Unit into Production Unit of Pellet from Fallen Leaves and Twig
Authors: Abdul Rahman Fadil , Utomo Gendewa , Purwadi Indra , Susanto Herri
Published: April 2021

Conversion of fallen leaves and twigs from urban waste into pellets may be one of several options to reduce the amount of waste transported to the landfill. However, the production of pellet needs very high mechanical energy or electricity. A case study has been conducted to evaluate the advantages and disadvantages of integrating a gasification technique into the production unit. In this integrated unit, the source of electricity for the pellet production was based on the conversion of a portion of pellet product to gaseous fuel which was then used as substitute of diesel fuel for running an electricity generator set. Three scenarios for supplying the electricity were compared: (i) scenario-A: from PLN (national grid, coal fired power plant), (ii) scenario-B: diesel-generator set; and (iii) scenario-C: diesel-genset and gasification unit. Total CO2 emissions in the production of pellet were as follows (kg CO2 eq /ton pellet): 81.8, 47.2 and 16.3 for scenario-A, B and C respectively. Due to the addition cost of investment, the integrated pellet production and gasification unit needed a Payback Period of about 5.6 years, while those of diesel based electricity and PLN were 5.1 and 4.8 years respectively. Data for this study was obtained from experiments on a pellet production unit with a design capacity of about 9 ton/week. The diesel engine was run in dual fuel mode using producer gas from the gasification of pellet. The producer gas heating values were in the range of 3300-4600 kJ/Nm3. Oil saving in dual fuel operation was up to 70%.
Food Safety Analysis and Improvement Concept of p -Carotene Extraction from Fungal Fermented Palm Oil Empty Fruit Bunches (EFB); Extraction Method and Solvent Selection
Authors: Amir Muhammad Syahdan , Novia Clara , Qodim Syafaatullah Achmad
Published: April 2021

Palm oil is one of the main agricultural commodities in Indonesia. Beside CPO and PKO as the main downstream product, the palm oil industry also produces solid wastes such as shells, fibers, and palm oil empty fruit bunches (EFB). Palm oil EFBs are often dumped nearby the palm oil plantations and being left to be decomposed, but several literature studies indicated that palm oil EFB still contained oil residue rich in β - carotene as well as other lipids components dissolved on it. β - carotene is among the major products of the food industry which have been widely employed as nutrients, food colorants, and additives. It serves as antioxidants and so-called pro-vitamin A. The previous research used n-Hexane as a solvent in β - carotene extraction from fungal - fermented palm oil EFB, whereas n-Hexane has a moderate toxicity level and low solubility of β - carotene which is only 600 ppm. Quality and food safety aspects of β - carotene extract haven’t been reviewed or analyzed yet. This paper will be focused on the food safety analysis and improvement concept that can be applied in the extraction method and appropriate solvent selection to obtain high-quality extracts of food-grade β - carotene from fungal - fermented palm oil EFB. Toxicity level and the Hansen Solubility Parameter (HSP) simulation results are the main criteria for solvent selection, while thermal stability, operational cost, and practical aspects are being considered to choose a better extraction method. Based on the HSP simulation results and all criteria mentioned before, n-Hexane can be substituted with 3 recommended solvents; D-Limonene, Tetrahydrofuran (THF), or Tetrahydrofurfuryl Alcohol. According to the economic analysis, the maceration method using THF at room temperature is being preferred to the soxhletation method. Moreover, food safety analysis is being reviewed based on HACCP principles.
Pediocin and Grape Seed Extract as Antimicrobial Agents in Nanocellulose Biobased Food Packaging: A Review
Authors: Weslie Timotius , Felixius Vincent , Amala Zulfah , Shofinita Dian
Published: April 2021

The food industry is a life-long and highly demanded industry as it is an essential human need. Food safety has become an urgent discussion related to this industry since the foodborne disease has gradually increased. One of the causes of the disease is L. monocytogenes, usually discovered in fresh meat, ready-to-eat meat, vegetables, and milk. L. monocytogenes causes an infection known as listeriosis. Food packaging plays an essential role as it protects the food from external contaminants to increase the shelf life. The high usage of conventional food packaging derived from fossil fuel contributes to the environmental issue as it creates long-term wastes. Therefore, biobased food packaging has been in favor as it is biodegradable. However, it lacks antimicrobial properties, so the development of biobased material as the antimicrobial food packaging is a potent solution in the food safety scope. This review paper intends to summarize current advancements in incorporating antimicrobial agents with nanocellulose biobased food packaging to increase the packaging’s functional value. Pediocin is the antimicrobial agent produced by Pediococcus sp. integrated with Grape Seed Extract (GSE), which gives an antioxidant property that boosts the food packaging’s antimicrobial effect. Observations show that incorporating these antimicrobials agents obstructs the growth of L. monocytogenes in biobased food packaging. Incorporating antimicrobial agents into nanocellulose matrix shifts the tendency to make biobased packaging that gives better mechanical strength and longer shelf life. Overall, this greener antimicrobial food packaging could be a solution to environmental waste as well as foodborne pathogens.
Production of Coconut Oil and Protein for Food and Cosmetic Ingredients
Authors: Lestari Dianika , Ridho Rahmani Amilah , Ariono Danu
Published: April 2021

Coconut (Cocos nucifera) is a tropical plant that is almost spread throughout the archipelago. Coconut is a plant of the genus Cocos widely used in various fields ranging from food to cosmetics. Most coconut parts can be utilized so that the coconut is dubbed a versatile plant and has high economic value. This tree has a fruit which is also called coconut. Coconut fruit is the most widely used and processed. Coconut meat can be directly consumed or processed into coconut milk, coconut flour (desiccated coconut), and cooking oil. Coconut oil was obtained from dried or fresh coconut flour using the Soxhlet extraction method with organic solvents. Defatted coconut flour contained a high protein of approx. 19-20%. Coconut protein has a good quality compared to other vegetable protein sources. This research investigated solvent’s effect on solid ratio and oil content on coconut protein extraction yield and recovery from coconut flour. Based on experiments, the highest value of extracted protein and yield was obtained after coconut flour extraction at a solvent to flour ratio of 30 g/g. Coconut protein isolate and coconut whey protein were expected to have different functional properties which need to be further evaluated to determine their application as cosmetics or food ingredients.
Techno-economic Analysis: Antioxidant-Rich Natural Colorant Production from Dragon Fruit Peel
Authors: Shofinita D , Bindar Y , Dinnita R U , Rizqi F
Published: April 2021

In this study, the economics of the various way production of natural colorant has been evaluated, specifically related to the effect of the drying methods: spray drying and freeze-drying. It has been found in this study that, the manufacturing costs of the food colorant in the form of extract, spray-dried powder, and freeze-dried powder were USD 6.01/kg, USD 29.89/kg, and USD 56.6/kg total solid content, respectively. The economic parameters consist of NPV, DPBP, PVR, and IRR of powder production using spray drying method were USD 1,989,412.68, 4.3 years, 3.31 and 20.6%, respectively, while that of using freeze-drying were USD 2,156,866.29, 7.27 years 1.78, and 8%. It is also known that drying using spray drying shows better economic parameters than freeze-drying. The sensitivity analysis of powder production using the spray drying method shows that the selling price parameter is a parameter that has a significant effect on the economics of production activity, followed by the cost of peel and cost of labor.
Multi-Objective Optimization of Blending Strategy of FAME, HVO, and Petroleum Diesel
Authors: Mustika Shanti , Wahyu Purwanto Widodo
Published: April 2021

The utilization of biofuels based on palm oil could decrease greenhouse gasses (GHG) emitted by fossil fuels. The aim of this research is on the optimization of blending strategy of Fatty Acid Methyl Esters (FAME), Hydrogenated Vegetable Oil (HVO), Diesel CN48 (DCN48), and Diesel CN53 (DCN53) to meet the fuel quality standard, Euro2 and Euro4 by minimizing levelized cost of fuel supply and GHG emission. The process simulation is performed by Aspen Plus software, proceed by Life Cycle Analysis (LCA) calculation. The optimization is carried out by General Algebraic Modelling System (GAMS) with Cplex solver. The result showed the percentage of the optimal blending composition of fuel quality Euro2 were FAME 43.9-51.1%, HVO 2.6-40.1%, DCN48 15.3-17.6%, and DCN53 46.3-100% with LCOE was 0.55-0.864 USD/Liter and GHG intensity 599.46-3000.78 gCO2eq/Liter. For Euro4 specification consists of FAME 32.5%, HVO 28.6%, and DCN53 38.8% with LCOE were 0.637-0.786 USD/Liter and GHG intensity of 902.69-2863.03 gCO2eq/Liter.
Simulation of CO2 Capture Process for Coal based Power Plant in South Sumatra Indonesia
Authors: Eviani M. , Devianto H. , Widiatmoko P. , Sukmana I. F. , Fitri H R , Yusupandi F.
Published: April 2021

Indonesia committed to reduce greenhouse gas emission by 29% in 2030. Carbon dioxide (CO2) emissions from flue gas in coal power plant must be captured to reduce greenhouse gas emissions. Technology to decrease greenhouse gases on a large scale and in a relatively short period is Carbon Capture and Storage (CCS). Chemical absorption method is a more advantageous CCS technology than other methods owing to high efficiency, low cost, and mature technology. Solvents in chemical absorption include amine-based solvent such as monoethanolamine (MEA) was frequently utilized to absorb CO2 from low-pressure flue gas streams, especially fossil fuel-based power plant, owing to rapid reaction rate with CO2 and low cost of raw amines compared to other amines. In this study, Aspen Hysys was used to simulate the CO2 capture process and 30 wt% of MEA was selected as a solvent which is mainly handy for CO2 capture from flue gas. The results show that lean amine temperature, flue gas temperature, and regenerator feed temperature has effects on the CO2 capture and energy consumption. The rich-split stream configuration was developed to examine energy reduction in various split fractions. The minimum in energy consumption and reboiler duty occurs when 30% of the solvent is split to the top of the column.
Integrated Biorefinery Technology: Monetization of Oil Palm Empty Fruit Bunch to Biofuel & Bio-based Chemicals, and Beyond
Authors: Mariyana Rina , Azkiya Choliq Azka , Adi Rahmanto Kharis , Nugroho Yusuf , Purwadi Ronny , Kresnowati MTAP , Septiningrum Krisna , Frans B.M. Dabukke
Published: April 2021

As the largest producer of palm oil, Indonesia has abundant oil palm empty fruit bunch (EFB), as one of the solid wastes produced from palm oil mill, which utilization has not yet been optimal although it has a potency to be used as feedstock for biofuel and bio-based chemicals. However, due to the recalcitrant characteristic of EFB as lignocellulosic material, EFB conversion into biofuel and bio-based chemicals has been a challenge, especially in regard to its economic viability. To obtain the economically viable of the conversion of EFB, the integrated EFB biorefinery technology concept was proposed to produce multiple products which are precursors for biofuel and bio-based chemicals. This paper presents the integrated EFB biorefinery technology concept, economic analysis of the technology, the role of the technology for circular bioeconomy in Indonesia, and the biorefinery industrialization concept in Indonesia as part of an effort for “Making Indonesia 4.0”.
Microplastic pollution in Surabaya River Water and Aquatic Biota, Indonesia
Authors: Lestari P , Trihadiningrum Y , Firdaus M , Warmadewanthi I D A A
Published: April 2021

Microplastics (MPs/MP) have been considered as an emerging environmental threat worldwide. It occurs due to its persistent, ubiquitous presence, and potential ecotoxicological risks to almost all aquatic environments. The MPs could release chemical additives and adsorb persistent organic pollutants. It could also be ingested mistakenly by aquatic biota due to its similarity with their original prey’s size and colour. This situation could impact water resource quality, aquatic biota biodiversity, even human health. Additionally, rivers have been estimated as the main pathway of plastic transport from the land to the ocean. Surabaya River, is the main lower part of the Brantas, which is one of the top 20 plastic polluted rivers globally. The Surabaya River takes essential role in clean water supply for Surabaya City, aquatic biota habitat, and irrigation. This study aimed to investigate the distribution and characteristics of the MPs in water and aquatic biota in Surabaya River. Fish and bivalve were selected as the representative aquatic biota due to their specific habitat, movement, and feeding behavior. Water and biota samples were collected from five sampling sites in the river. The MP abundance in the water ranged from 9.66 ± 8.87 to 21.16 ± 19.35 particles/m3. The highest MP abundance (21.16 ± 19.35 particles/m3) was found at Joyoboyo. The MP abundance in the fishes ofOreochromis niloticus, Barbonymus gonionotus,and in the bivalves ofElongaria orientaliswere 105.25 ± 45.07 – 155.50 ± 61.96; 62.13 ± 20.33 – 155.00 ± 81.71; and 36.00 ± 13.67 – 76.17 ± 29.46 particles/individual, respectively. The MPs in the water were dominated by film shaped, transparent coloured particles. Meanwhile, the MPs in the fishes and the bivalves were generally found in transparent and black fiber particles. Only small amounts of film particles were discovered in the biota. Moreover, most of the MPs in the water and the biota were in large sized (1 – 5 mm) particles.
Effect of Graphene Oxide on the Performance of Cellulose Acetate/ Polyethylene Glycol Membrane with Blending Method for Desalination of Brackish Water
Authors: Nyamiati R D , Devi B C , Febriansyah B A , Ramadhani A , Rahmawati Y , Nurkhamidah S
Published: April 2021

Polymeric membrane must be strong during the reverse osmosis process. Carbon-based materials like carbon nanotubes (CNTs), graphene, and its derivative graphene oxide (GO) have strong mechanical strength, high resistance to strong acids/ alkaline and organic solvents, and easy in accessibility. In this study, GO were blendingd into Cellulose Acetate/ Polyethylene Glycol (CA/PEG) membranes prepared by phase inversion method. Performance of the membrane was evaluated from the water flux, salt rejection, and permeability. Morphology, hydrofilicity, tensile strength were isvestigated by using Scanning Electron Microscopy (SEM), Fourier-Transformed Infra-Red (FTIR) and contact angle analysis, and Dynamic Mechanical Analysis (DMA), respectively. The experiment results show that hydrophilicity and porosity increase with the addition of GO with the addition of 0.005% GO exhibits the highest value of them resulting membrane with better flux and salt rejection values as compared to the GO-free membrane. With the addition of 0.005 wt% GO resulted in salt rejection (%R) 83.3% and flux permeate (F) 2194 L/m2.h. and tensile strength of 0.0148 Mpa. Membrane with CA/PEG/GO has more advantages, where GO affects the porosity of the membrane by increasing the pore size such as fingers and reducing the thickness of the wall which will result in increased membrane performance ability.
Kinetic studies and performance analysis of Indonesian rice husk pyrolysis
Authors: Kasmiarno L D , Steven S , Rizkiana J , Restiawaty E , Bindar Y
Published: April 2021

Rice husk is abundantly available biomass in Indonesia and it can be a potential source of high-value energy source. In the present work, pyrolysis of rice husk was subjected to various temperature and used as a method to produce bio-oil. The decomposition profile of rice was examined at different heating rates (10, 20, 30, and 40°C/min) using a thermogravimetric analysis (TGA) method. The pyrolysis kinetics were evaluated using three different kinetic models: Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), and Coats-Redfern (CR). The activation energy for KAS, OFW, and CR was centered at 251.62 kJ/mol, 253.32 kJ/mol, and 33.92 kJ/mol, respectively. Varying activation energy with conversion was observed, which reveals that the pyrolysis of rice husk processes through complex reaction. The production of bio-oil from rice husk using pyrolysis method was studied at different temperature conditions (300, 400, 500, 600°C). Results showed that bio-oil and gas products increase at higher temperature. The highest yield of bio-oil was produced at 600°C with 46.3 grams (37%-wt). The specific test showed that the density, viscosity, and acid value of bio-oil decreased at higher temperatures indicating that different pyrolysis conditions might lead to the different bio-oil quality.
Application of Reverse Flow Reactor for Vent Gas Emission Reduction in Catalytic Oxidation Unit at Purified Terephthalic Acid Plant
Authors: Hanafiah F M , Budhi Y W
Published: April 2021

PTA (Purified Terephthalic Acid) manufacturing process generates waste gases containing VOC (Volatile Organic Compounds) that have negative health effects, one of it is benzene. Catalytic oxidation method consists of a recuperative (need external energy to reach the reaction temperature) and reverse flow reactor (RFR) which uses the principles of auto thermal (requires no external energy). Fuel consumption for heating the feed gas is a major operating cost in the catalytic oxidation, so that the fuel reduction becomes important. The objective of this study is to assess the technical possibility of RFR to lower the fuel consumption; and to assess the operating conditions for autothermal conditions. The mathematical model consisted of the unsteady state mass and energy balances and was numerically solved using a software package of FlexPDE verion 6.32. The recuperative system was simulated in the steady state condition, while RFR with the same amount of catalyst was simulated in the unsteady state condition. As the key parameter, the switching time was varied to consider the performance of RFR. At various switching times and inlet concentrations, the autothermal was achievable even heat extraction was required to prevent the catalyst overheat. At the feed gas linear velocity of 1.2 m/s and the switching time of 7.5 s or higher, RFR provides energy saving that is equivalent to US$ 0.1208/ton feed gas up to US$ 0.7248/ton of feed gas compared to recuperative system.
Titania Modified Silica from Sugarcane Bagasse Waste for Photocatalytic Wastewater Treatment
Authors: Hendra Saputera Wibawa , Egiyawati Candra , Setyani Putrie Amellia , Fathoni Amri Aryan , Rizkiana Jenny , Sasongko Dwiwahju
Published: April 2021

Photocatalytic oxidation is one of the technologies to overcome pollution that can be applied for air and water purification. TiO2 has been widely used as a photocatalyst, however, several disadvantages of TiO2 including low absorption of visible or solar radiation, rapid recombination of electron and hole as well as low stability limits its practical applications especially for wastewater treatment. Thus, to overcome this problem, this study aims to develop highly adsorbent photocatalyst using TiO2/SiO2 composites with sugarcane bagasse waste act as SiO2 source. The experimental results show that the photocatalytic performance of TiO2/SiO2 composite in the decolorization of methyl orange exhibits three-fold enhancement compared to neat TiO2. Several catalyst characterizations were obtained including X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray fluorescence (XRF). Characterization data show that a phase transformation was obtained from amorphous to crystalline phase by increasing TiO2 content. These results proved that the feasibility of SiO2 from sugarcane bagasse waste coupled with TiO2 can be utilized for wastewater degradation.
Improved Visible Light Activity of Copper Oxide/Carbon Nitride Photocatalysts Prepared by Photodeposition for Phenol Degradation
Authors: Sagita C P , Yuliati L
Published: April 2021

A series of copper(II) oxide deposited on carbon nitride (CuO/CN) as visible light-active photocatalyst was successfully prepared via a photodeposition method. The CuO modification was carried out to improve the photocatalytic activity of CN having fast electron-hole recombination. The CuO loading was varied from 0.05 to 0.5 wt% and the photodeposition was carried out at room temperature under UV light illumination. The CuO/CN samples were confirmed to have similar optical properties and functional groups to those of the unmodified CN. Meanwhile, the emission intensity of the CN decreased with the increase of the copper species loading, which could correspond to the suppression of charge recombination on the CN. After a 24-h reaction under visible light irradiation, the best photocatalyst, i.e. the CuO(0.1)/CN, gave 41.7% phenol degradation, which was almost two times higher than the unmodified CN (21.3%). However, the photocatalytic activity decreased when the added copper species was more than 0.1 wt%. Therefore, the optimum amount of copper species deposited on the CN surface would have a prominent contribution to improve the photocatalytic activity. It was also confirmed that holes, hydroxyl radicals, and superoxide radicals were important for the photocatalytic degradation of phenol on the CuO(0.1)/CN.
High photocatalytic activity of zinc metatitanate materials for phenol photodegradation
Authors: Priyangga K T A , Kurniawan Y S , Yuliati L
Published: April 2021

In this work, we synthesized zinc metatitanate (ZnTiO3) through a sol-gel method strictly using a 1:1 mol ratio of zinc nitrate and titanium(IV) isopropoxide as the precursors. The calcination temperature was set to 700, 900, and 1100 °C to give ZM-700, ZM-900, and ZM-1100, respectively. These ZM materials were characterized using X-ray diffractometer (XRD), diffuse reflectance ultraviolet-visible (DR UV-vis), Fourier transform infrared (FTIR), and fluorescence spectroscopies. The XRD analyses showed that the ZM-700 contained both cubic-ZnTiO3 and rhombohedral-ZnTiO3 phases with a small part of ZnO, while the ZM-900 contained cubic-ZnTiO3 and cubic-Zn2TiO4. In contrast to the ZM-700 and the ZM-900, the ZM-1100 contained cubic-Zn2TiO4 and rutile TiO2 as the main phases with a very small part of the ZnTiO3 phase. The formation of these crystal phases was also supported by their DR UV-vis spectra, FTIR analysis, and fluorescence spectra. Photocatalytic degradation of phenol was carried out under UV light irradiation for 1–24 h. The kinetic study revealed that the reaction followed first-order, in which the reaction rate constants were 0.0351, 0.0323, 0.0298 h−1 for the ZM-700, ZM-900, and ZM-1100, respectively. This study demonstrated that the formation of ZnTiO3 was crucial to obtain high photocatalytic activity on the ZM materials.
TiO2/AC Composites for Adsorption-Photocatalytic of Methyl Orange
Authors: Kartikowati C W , Wulansari A L , Poerwadi B , Supriyono  , Arif A F , Sulistyaningsih T , Arutanti O
Published: April 2021

Herein, the adsorption-photocatalytic performance of composite titanium dioxide (TiO2) and Activated Carbon (AC) to decompose methyl orange was investigated systematically. This work demonstrated the synthesis of TiO2/AC composite via the sol-gel method. After getting the composite TiO2/AC under different ratios of AC, the prepared particles were then annealed at 500°C for 2 h. The presence of AC detected by Fourier transform infrared (FTIR) spectra at 1028 nm. Based on Brunauer–Emmett–Teller (BET) analysis, the result showed that the prepared particles specific surface area increased by increasing the AC ratio. The prepared photocatalyst was used to decompose methyl orange under UV light irradiation for 90 minutes. From the photocatalytic performance, the additional AC did not influence the adsorption process significantly under dark conditions. Interestingly, during the irradiation process, methyl orang could be decomposed until 62.5%, which means 15% higher than that of bare TiO2. The present result showed that an additional AC could enhance photocatalytic performance due to its ability as an electron transfer and avoid the recombination process between electrons and holes.
Aperiodic biomimetic Vogel spirals as diffractive optical elements for tailored light distribution in functional polymer layers
Authors: Merkel M , Schemme T , Denz C
Published: April 2021

The biomimetic, deterministic aperiodic golden angle Vogel spiral lacks both translational and rotational symmetry and exhibits circularly symmetric scattering rings in Fourier space. We present a versatile and low cost method for maskless fabrication of a Vogel spiral relief grating by illumination of a photoresist with laser light complexly structured using a spatial light modulator and subsequent transfer of its negative into a polymer layer via replica molding. We investigate its diffractive properties and present as one application its implementation as a surface structure, leading to an efficiency enhancement of 18% in an organic solar cell.
Investigating the characteristics of a magnetorheological fluid damper through CFD modeling
Authors: Badri Yousif , Syam Thaer , Sassi Sadok , Hussein Mohammed , Renno Jamil , Ghаni Sаud
Published: April 2021

Computational Fluid Dynamics (CFD) analysis is conducted on mono-tube vehicle MRF damper investigated experimentally in a previous study. In this study, the fluid of the type MRF-132DG was inserted inside a damper of a car rear suspension system. The CFD analysis describes the fluid flow through the internal orifices between the compression and the rebound chambers. Averaged Navier–Stokes equations were solved by the SIMPLE method, and the RNG k-ε was used to model the turbulence at the fluid crossing through the orifices. All the CFD model boundary conditions’ values were set to the same values reported in the previous experimental study, except for the viscosity values. When varying the applied magnetic field density, the changes of MRF’s viscosity values were assessed by using a viscosity meter. Results showed a viscosity increase of 70% when the magnetic field excitation current was elevated from 0 A to 5 A. The damping forced and damping values were calculated using the rebound and compression static pressures obtained from the contour plots. It was also observed that the damping values exponentially increase with the increase in viscosity. The results of the CFD simulation were compared against those from the experiments, and good matching was observed.
Room temperature ferromagnetism in N-implanted MgO: synergistic effects of intrinsic and extrinsic defects
Authors: Wang Xingyu , Ma Chunlin , Wang Xiaoxiong , Zhou Weiping , Tan Weishi
Published: April 2021

N-implanted MgO single crystals were prepared and their magnetic properties were studied. High Resolution x-ray diffraction, photoluminescence, and x-ray photoelectron spectroscopy measurements confirmed that both intrinsic defects (Mg vacancies, oxygen vacancies) and extrinsic defects (N-related defects) were presented in the implanted samples. Ferromagnetism was detected in the samples. The saturation magnetization (Ms) of the samples increases with the concentrations of Mg vacancies and N-related defects. We conclude that the enhanced Ms should be ascribed to the synergistic effects of intrinsic and extrinsic defects. The magnetic properties of various composite defects were also studied by first principle calculations. The results suggest that the ferromagnetism is mainly originated from the configurations of VMg (Mg vacancy)+NO (N substituting for O).
Energy-momentum tensor for the electromagnetic field in a dispersive medium
Authors: Heredia Carlos , Llosa Josep
Published: April 2021

On the basis of a non-local Lagrangian for Maxwell equations in a dispersive medium, the energy-momentum tensor of the field is derived. We obtain the Field equations through variational methods and an extension of Noether theorem for a non-local Lagrangian is obtained as well. The electromagnetic energy-momentum tensor obtained in the general context is then specialized to the case of a field with slowly varying amplitude on a rapidly oscillating carrier.
Manganese and cobalt substituted ferrite nanoparticles synthesized via a seed-mediated drip method
Authors: Yan Zichun , FitzGerald Sara , Crawford Thomas M , Mefford O Thompson
Published: April 2021

To produce multi-dopant ferrite nanoparticles, the ‘Extended LaMer’ and seed-mediated growth techniques were combined by first utilizing traditional thermal decomposition of metal acetylacetonates to produce seed particles, followed by a continuous injection of metal oleate precursors to increase the volume of the seed particles. With the choice of precursors for the seeding and dripping stage, we successfully synthesized particles with manganese precursor for seeding and cobalt precursor for dripping (Mn0.18Co1.04Fe1.78O4, 17.6 ± 3.3 nm), and particles with cobalt precursors for seeding and manganese precursors for dripping (Mn0.31Co0.74Fe1.95O4, 19.0 ± 1.9 nm). Combining transmission electron microscopy, energy-dispersive x-ray spectroscopy, x-ray diffraction, and vibrating sample magnetometry, we conclude that the seed-mediated drip method is a viable method to produce multi-dopant ferrite nanoparticles, and the size of the particles was mostly determined by the seeding stage, while the magnetic properties were more affected by the dripping stage.
Coherent Raman scattering microscopy for chemical imaging of biological systems
Authors: Zhang Chi , Aldana-Mendoza Jesus A
Published: April 2021

Coherent Raman scattering (CRS) processes, including both the coherent anti-Stokes Raman scattering and stimulated Raman scattering, have been utilized in state-of-the-art microscopy platforms for chemical imaging of biological samples. The key advantage of CRS microscopy over fluorescence microscopy is label-free, which is an attractive characteristic for modern biological and medical sciences. Besides, CRS has other advantages such as higher selectivity to metabolites, no photobleaching, and narrow peak width. These features have brought fast-growing attention to CRS microscopy in biological research. In this review article, we will first briefly introduce the history of CRS microscopy, and then explain the theoretical background of the CRS processes in detail using the classical approach. Next, we will cover major instrumentation techniques of CRS microscopy. Finally, we will enumerate examples of recent applications of CRS imaging in biological and medical sciences.