Indonesia Conference Directory

Corresponding Author
Ahmad Taufiq

Institutions
Department of Physics, Universitas Negeri Malang, Jl. Semarang 5, Malang 65145, Indonesia.

Abstract
Regarding the physical and chemical performances, Fe3O4 and multi wall carbon nanotubes (MWCNT) combined with with other metal oxide such as titanium dioxide opens new opportunity to be widely used for energy application such as for supercacitor. In this paper, we report the preparation of Fe3O4/MWCNT nanocomposite combined with titanium dioxide using sonochemical-precipitation method. The nanocomposite was characterized using X-ray diffractometer, Fourier transform infra-red spectroscopyr, and scanning electron microscopy, and Uv-Vis spectrometer. The results of diffraction data analysis showed the presence of crystalline phase in nanocomposite derived from Fe3O4 and titanium dioxide with cubic inverse spinel and anatase structures, respectively. The existence of MWCNT was then confirmed by functional groups data which indicated the vibration of C=C functional group at the wavelength of 1400-1600 cm-1, while the vibration of Fe-O was detected at the wavelength of 409 cm-1 and 667 cm-1 overlapped with Ti-O functional group. MWCNT considered to be crosslinked the surface of Fe3O4 or titanium dioxide nanoparticles. Furthermore, the bandgap energy of the nanocomposite were 2.2 eV for Fe3O4/MWCNT, and 3.2 eV for Fe3O4/MWCNT.

Keywords
Fe3O4, MWCNT, titanium dioxide, iron sand, sonochemical, precipitation.

Topic
Smart materials

Link: https://ifory.id/abstract/YBgavPALjWh8

Corresponding Author
Samsul Hidayat

Institutions
(1)Brawijaya Volcano and Geothermal Research Center, UniversitasBrawijaya, Malang, Indonesia
(2)Faculty of Sciences, UniversitasNegeri Malang, Indonesia
(3)Lab., of Measurement & Circuit System, UniversitasBrawijaya, Malang, Indonesia

Corresponding author : sukir[at]ub.ac.id

Abstract
ABSTRACT Cangar Hot Springs (CHS) located at flank of Arjuno-Welirang Volcano Hosted Geothermal Field in Batu city, East Java has a high potential as pilot project of regional in the frame of Ecotourism and Edu Techno Park development. A few hot spring found in the Arjuno-Welirang volcanic complex, such as Padusan hot spring, Songgoriti hot spring, Kasinan hot spring, and Cangar hot spring. Based on previous Peak Ground Acceleration observations, the area was concluded a safe zone indicated by low seismic index. Furthermore, based on the self potential investigations, the fluid flow around CHS can be predicted that the direction of hot fluid flow spread from southeast to northwest. This results can be used to consider a high potential for Eco tourism of CHS mainly related to the use of hot springs and community education related to volcano hosted geothermal. We develop a concept and observed some aspect to improve the development CHS area as Ecotourism and Edu Techno Park. In addition, the visual observation shows that the occurrence of solfatara and fumaroles with magmatic gasses indicated the existence of a volcanic geothermal system in the subsurface around Arjuno-Welirang volcano hosted geothermal complex. This visual observation can be done direct from the developed Cangar Techno Park area on UniversitasBrawijaya for monitoring of ArjunoWelirang volcanic eruption as part of integrated ecotourism concept and idea to community education for developing of geothermal prospecting area.

Keywords
Cangar Hot Spring (CHS), ArjunoWelirangvolcano, Ecotourism, Edu Techno Park

Topic
Renewable Energy

Link: https://ifory.id/abstract/b8x4a27NnpQX

Corresponding Author
Didin Zakariya Lubis

Institutions
State University of Malang

Abstract

Keywords
Punch Tool Speed, Material Effect, Element Method

Topic
Smart materials

Link: https://ifory.id/abstract/kDx4uzAPejW7

Corresponding Author
Sukarni Sukarni

Institutions
1Department of Mechanical Engineering, State University of Malang, Semarang Street 5, Malang 65145, Indonesia
2Centre of Advanced Materials for Renewable Energy, State University of Malang, Semarang Street 5, Malang 65145, Indonesia

Abstract
Pyrolytic characteristics and kinetics of cassava stalk as a renewable energy source were studied using a thermogravimetric (TG) analyzer. Around 10 mg powder of the sample was heated up in the chamber under inert conditions with 50 ml/min nitrogen flow rate and operated at a heating program of 20 oC min-1. The pyrolysis process of cassava stalk was taken place into three main stages, in which the peak reaction occurred at the second stage with 70% of the mass was degraded. The differential method of Arrhenius kinetic evaluation resulted in the values of reaction order (n) that was 0.99, activation energy that was 89.46 kJ/mol and logarithmic frequency factor (logA) was 7.7 min-1.

Keywords
Pyrolysis, Thermogravimetric, Cassava Stalk, Arrhenius Method

Topic
Biomass, Biofuel

Link: https://ifory.id/abstract/84YhEVcxpu3z

Corresponding Author
Fitria Tahta Alfina

Institutions
1Teacher Training and Education Faculty, Sebelas Maret University, Indonesia
2School of Environment and Society, Tokyo Institute of Technology, Japan

Abstract
Abstract: Among the keys to successful industrialization in the field of renewable energy is the availability of ready-to-work human resources in the industry. Although Indonesia has a lot of potential renewable energy, the development of its utilization is still small. One obstacle is the lack of development of industries that develop renewable energy that are not supported by the readiness of human resources ready for work in the field. Indonesia has a very large renewable energy potential, but the utilization is still not maximal. One of these obstacles is the lack of human resources that is in the way it is an effort to improve the quality human resources to achieve the development of maximum renewable energy is through education. Furthermore, good, unknown and unique social technical education technical and Vocational School is a place to start the development of the individuals awareness of the individual who is traveling vocational education, about renewable energy sources. A survival surgical renewal of source of energy is distributed to 82 respondents from different education class levels. Respondents consist of education students of vocational techniques of engineering machinery and Vocational School students Department of engineering machinery. This study will be one of the reference in determining the direction of national policy especiallyin education in the field of development of renewable energy in Indonesia.

Keywords
Renewable energy, Awareness, Vocational School, Education Policy

Topic
Renewable Energy

Link: https://ifory.id/abstract/32frcLFmE4KJ

Corresponding Author
Poppy Puspitasari

Institutions
Politeknik Manufaktur Bandung, Universitas Negeri Malang

Abstract
Any defect in casting products should be avoided at all cost, and treatment must be done as early as possible. One alternative to produce a sound-casting product is using simulation application such as SOLIDCast to analyze a defect, which this research used to analyze the shrinkage defect in Lifter Cooler Big made from SCH 11 material. This research was conducted at the Foundry Laboratory, Bandung Polytechnic of Manufacturing and aimed to investigate the main causal of shrinkage in Lifter Cooler Big. The first step of the research was to analyze the shrinkage defect on three Lifter Cooler Big products. It was followed by the visual inspection test, Liquid Penetrant Testing (LPT), and Scanning Electron Microscope (SEM) test to verify the defect. Next was to calibrate the SOLIDCast simulation application to obtain material and sand parameters matching the real products condition. Using material density analysis from SOLIDCast simulation, a defect prediction was obtained similarly to the shrinkage on the samples. The result stated that the sand condition was in 1.5 W/m&

Keywords
Shrinkage, SCH 11, Lifter Cooler Big, SOLIDCast Simulation software

Topic
Smart materials

Link: https://ifory.id/abstract/qnHPrWTXUdVB

Corresponding Author
Galih Kurniawan

Institutions
State University of Malang

Abstract
This study aims to analyze knee joint implants from Ti6Al4V alloys using experimental and simulation methods with Finite Element Analysis (FEA). The experimental method was designed to observe the microstructure, crystal size, and chemical composition of Ti6Al4V. The simulation method is designed to analyze total deformation, maximum principle stress, and maximum shear stress with time and load variations. This study uses SEM, XRD, and XRF analysis to obtain data from the experimental method while the FEA simulation uses ANSYS software. Simulation is done based on the activities of walking, jumping, and walking down stairs for 0-0.01 seconds. SEM results indicate that Ti6Al4V has parallel strokes after the cutting process and resembles the shape of needles that regularly resemble weaving. The XRD results show that the crystal size is 2.906 x 10-5 nm. Then, the XRF results show that Ti6Al4V has 85% Ti, 2.7% Al, and 4% V. The FEA analysis results show that the knee joint implant has a total deformation of 0.00013637 mm in walking activity, 0.00015165 mm in jumping activity, and 0.00015706 mm in activity down the stairs. The maximum shear stress is 1.0852e7 Pa in the running activity, 1.4383e7 Pa in the jumping activity, and 1.2498e7 Pa in the activity down the stairs. The maximum principal voltage on the activity goes 1,404e7 Pa, at the activity jumping 1.7546e7 Pa, and on the activity down the stairs 1.6171e7 Pa.

Keywords
Simulation, Characterization, Ti6Al4V

Topic
Smart materials

Link: https://ifory.id/abstract/H8vRNVQPMqpy

Corresponding Author
Dahried Wahyu Herlambang

Institutions
Electronic Engineering Polytechnic Institute of Surabaya

Abstract
A Three-phase induction motor is an electric machine that is widely used in the industry and electric vehicles. An Induction motor has some advantages such as strong and simple construction, relatively cheap prices with high reliability and low maintenance costs. To adjust the rotational speed of an induction motor can be driven by adjusting the input voltage and frequency. Usually, to change the input voltage and frequency was used a three phase inverter that requires DC voltage to be converted into three-phase AC voltage. However, this method has some disadvantages including non sinusoidal output voltage waveform also can cause high harmonics. Harmonics will cause an increase in losses that can decreasing the efficiency and disturbing the power system stability. The Direct Matrix Converter with Space Vector Modulation (SVM) method has several advantages that can solve the problem to get a good quality of electrical power system and stable performance can be obtained in driving three phase induction motor speed .

Keywords
Three-phase induction motor, Matrix converter, Space Vector Modulation (SVM), Harmonics.

Topic
Smart materials

Link: https://ifory.id/abstract/knCEv7AP8V6B

Corresponding Author
Robi Kurniawan

Institutions
1 Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang 5, Malang 65145, East Java, Indonesia
2 Centre of Advanced Materials for Renewable Energy, Universitas Negeri Malang, Jl. Semarang 5, Malang, 65145 East Java, Indonesia
3 Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603, Singapore

a)Corresponding author: robi.kurniawan.fmipa[at]um.ac.id

Abstract
The main keys in developing solar cells are their optical absorption and electron transfer (optical conductivity) levels. To enhance these two characteristics, an electron transport layer (ETL) was added to the solar cell, which is used to prevent electron recombination. Zinc oxide nanorod (ZnO NR) is one of the potential ETL candidates in the new generation of solar cells due to its high electron transfer. To optimize the use of ZnO NR in new generation solar cells, we combine NR ZnO with graphene, into a hybrid ZnO NR/graphene system. Optical absorption and conductivity of hybrid ZnO NR/graphene were studied using spectroscopic ellipsometry. A dramatic change in ellipsometry spectra has been observed, which increases with a higher number of graphene in the hybrid systems. Furthermore, the role of graphene on the optical absorption and conductivity of hybrid systems was investigated through fittings by applying the effective medium approximation (EMA) model. This study will provide a good understanding of optical absorption and optical conductivity of hybrid ZnO NR/graphene, which is an important key in the development of high-performance new generation solar cells.

Keywords
Hybrid ZnO NR/graphene, spectroscopic ellipsometry, optical absorption, optical conductivity

Topic
Smart materials

Link: https://ifory.id/abstract/gXP4hJuWQR3Y

Corresponding Author
nandang mufti

Institutions
UM

Abstract
Solar cell-based Copper Indium Gallium Selenide (CIGS) is one type of solar cell that has high efficiency. However, the most commonly used vapor deposition technique to deposit CIGS is a technique that requires high environmental control and cost. The research aims to produce thin-film CIGS with hot injection methods. Variations of the Decantation 4, 6 and 8 times were performed to acquire the pure CIGS nanoparticles carried out to study their influence on phases, crystal structures, morphologies, and optical properties at the same time to the methods of deposition of the Doctor Blade. CIGS Film is defied over the ITO substrate with the Doctor blade technique. The XRD diffraction pattern shows the structure of tetragonal crystals. CIGS grain size increases with the number of oleylamine solvent decantation processes. SEM results indicate that CIGS can be deposited evenly throughout the substrate surface. CIGS with decantation process as much as 8 times easiest to be deposited with the best properties to be applied as easy and cheap CIGS solar cell.

Keywords
CIGS, decantation oleylamine, hot injection, doctor blade

Topic
Renewable Energy

Link: https://ifory.id/abstract/YmP9T8x4BgHU

Corresponding Author
Ade Rifaldi

Institutions
(a) Departement of Chemistry, Faculty of Mathematics and
Natural Sciences, Universitas Negeri Malang, Jalan
Semarang 5 65145, Indonesia

Corresponding Author: idasna[at]um.ac.id

Abstract
Prussian Blue Like (PBL) complex compounds have been synthesized and studied as K-Ion Battery (KIB) electrodes. KIB can be developed as an alternative battery because its advantages are more cheaper and secure in comparison with L-Ion Battery (LIB). In this research, the complex compound of K2[Zn(Q)2][Co(SCN)6] was synthesized from K4[Co(SCN)6], Zinc(II) Chloride and Quinoline using a direct reaction method. Synthesized complex compounds was characterized through melting point, SEM-EDX, FT-IR, electrical conductivity,UV-Vis and cyclic voltammetry. The PBL complex has melting point 179-181degree C, electrical conductifity 468 microsiemens, and indicated an ionic compound. Characterization using FT-IR showed the pbl complex has a functional groups of thiocyanate and quinoline. The UV-Vis spectrum of K4[Co(SCN)6] and PBL complex shows absorption peaks at 619.5 and 519 nm. The PBL complex can be oxidized on 0.34 V.

Keywords
K-Ion Battery, Prussian Blue Like, cyclic voltammetry, cathode material

Topic
Energy Storage

Link: https://ifory.id/abstract/DAGnc3QUFeYW

Corresponding Author
Zaharul Azhar

Institutions
(a) State University of Malang Jalan Semarang 5, Malang 65145, Indonesia
*idasna[at]um.ac.id

Abstract
Lithium-ion Battery (LIB) is one of the best batteries for daily application, but lithium in the world is lack of abundance, so its worried it will be out of stock in the next few years. Another alternative is using the potassium ion based batteries. The most common cathode well used on potassium ion battery is Prussian Blue Like (PBL) compound. The purpose of this research is to synthesize PBL compound of zinc(II) chloride, quinoline, chromium(III) chloride hexahydrate, and potassium thiocyanate with mole ratio of 1:2:1:6 as well as the characterization of complex compound as material for Kalium Ion Battery. Synthesized Complex compounds form a dark greeny purple crystals and has a melting point of 182-185 celcius degree and act as ionic compound. Two peaks in the UV-Vis spectra indicate the presence of transition metal Cr3+ ion. XRD and EDX analysis showed the synthesized compound has empirical formula K[Cr(C9H7N)2(SCN)2][Zn(SCN)4], FT-IR analysis proved the presence of quinoline and thiocyanate ligands in complex compounds. Analysis of cyclic voltammetry showed the complex compounds has a reduction potential of -0.55 volts.

Keywords
Synthesis of complex compound, Prussian Blue Like, Kalium-ion Battery, cyclic voltammetry

Topic
Energy Storage

Link: https://ifory.id/abstract/MUWADdQxJNCb

Corresponding Author
Fauziatul Fajaroh

Institutions
Universitas Negeri Malang

Abstract
Until now, used cooking oil (jelantah) has not been utilized optimally. This study seeks to convert this waste into biodiesel. Used cooking oil usually contains high concentration of free fatty acids which can be converted into methyl esters through transesterification by methanol. This effort is in line with the increasing need for renewable energy sources. Because of the waste still contains high concentrations of free fatty acids, then it is necessary to think about the proper process and utilization of superior catalysts for transesterification. One of the allegedly superior catalysts is ferrit-based nanocomposite catalyst, namely CaO@CoFe2O4. This hypothesis is based on the properties of ferrite which are thermally and chemically stable and can be drawn by magnetic fields. The particles on the nanometre scale are thought to show high reactivity as a catalyst. The composite with strong base oxide CaO which is not soluble in methanol is also a supporting factor.The purpose of this study was to synthesize and to characterize CaO@CoFe2O4, then to study its potential as a catalyst in biodiesel production from used cooking oil in various weight percent of catalyst. The main steps include: (1) synthesis of CoFe2O4by coprecipitation; (2) Impregnation of CaO into CoFe2O4 and converted to CaO@CoFe2O4; (3) Characterization of the synthesized material was carried out by XRD, BET, and SEM/EDX; (4) application of CaO@CoFe2O4 to biodiesel production from used cooking oil; (5) characterization of biodiesel produced. Based on the results of XRD and SEM/EDX analysis, the CaO@CoFe2O4 catalyst has been successfully synthesized. At optimum condition, the addition of 4% catalyst in trans-esterification reaction of used cooking oil produced 95.27% of methyl esters. This means, CaO@CoFe2O4 is a catalyst that can be seeded in biodiesel production.

Keywords
Renewable energy, biodiesel, CaO@CoFe2O4, catalyst

Topic
Biomass, Biofuel

Link: https://ifory.id/abstract/k3R9zqUWbgcK

Corresponding Author
Mukhamad Suhermanto

Institutions
(a) Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Malang, Indonesia
(b) Purdue University, Mechanical Engineering, West Lafayette, IN, USA

Abstract
This paper presents the comparative techno-economic analysis on three different renewable energy sources (i.e. Solar (Thermal and PV) and Wind Energies (WE)) paired with two desalination systems (i.e. Multistage Flash (MSF), Multiple-effect Distillation (MED) and Reverse Osmosis (RO)). The aim of this investigation is to provide thorough technology and economic analysis on the renewable-energy-driven desalination system for Nusa Tenggara Timur (NTT) province. NTT has nationally most districts (20 regions) accounted for water drought every year due to low water precipitation and lack of fresh water resource. It is investigated numerically using Engineering Equation Solver (EES) taking account for most major input considerations. The Solar thermal driven desalination is used to power MSF and MED. The Solar PV and WE are utilized separately for the source of energy for RO system. The results can be utilized as major consideration on which technology should be applied to tackle the fresh water supply drought in NTT. In addition, the economic analysis provides ample explanation for the economic feasibility on the project to be applied. Based on the investigation, the Solar Thermal powered MED and MSF promises biggest feasibility techno-economically with lowest LCOEs.

Keywords
renewable energy, desalination, indonesia, techno-economic, reverse osmosis

Topic
Renewable Energy

Link: https://ifory.id/abstract/g7eRE6TynQHp

Corresponding Author
Yeny Rachmawati

Institutions
Sebelas Maret University

Abstract
This study will conduct a study on the attitudes of hotel tourist to renewable energy especially solar PV for hotel accommodation in Surakarta, Indonesia. This research has been carried out in many countries in the world in involving community participation to consider new policies. This research is important to do to obtain valid information by directly involving community participation. This is good for government and hotels use in taking new policies on energy. This study uses a survey method with questionnaire research instrument and emphasizes the problem of responses (feedback) to obtain a broad explanation through the attitudes of hotel tourist to the application of renewable energy in Surakarta. This study uses a quantitative approach with descriptive statistical data analysis and simple random sampling by formula of Slovin to determine the number of samples from the population with an error rate of 5%. This research looks for 336 samples in star hotels from 1 to 5 stars in Surakarta hotels. Visitor attitudes in reducing energy consumption were 74%, visitor attitudes in recognizing RES failures were 40%, visitor attitudes in paying extra for RES installation were 35%, visitors perception of solar PV installation on the roof at 55%, and visitors perceptions of solar PV installation on balconies were 78%.

Keywords
Renewable energy; Solar PV; Tourist hotel accommodation.

Topic
Renewable Energy

Link: https://ifory.id/abstract/LPZRtfaJubrx

Corresponding Author
zahir masrul

Institutions
State University Of Malang

Abstract
Dye Sensitized Solar Cells (DSSC) based on TiO2 material are very potential because of several advantages such as high photostability, high thermal stability and very effective for Dye absorption. However, TiO2 still has limitation in terms of electron mobility. It needs to be composited with other materials for electron mobility. Material that has a potential is ZnO material. beside that ZnO also has the same band gap range as TiO2. In this condition, the composite system of TiO2-ZnO becomes more potential to be used as a DSSC electrode. In the Photosupercapacitor system, with a high source of electrical energy from DSSC, a Supercapacitor unit with sufficient capacitance is also needed. In this case, the selection of capacitor electrodes is very influential. In this study, electrodes based on the BaTiO3-PVDF composite system were used. With the dielectric permittivity reaching 1700, BaTiO3 material is the main candidate for the supercapacitor dielectric material. But BaTiO3 has limitations such as fragile and unflexible nature. This limitation can be overcome in combination with the PVDF polymer which has advantage in terms of its flexible properties. Besides that, the dielectric permittivity is the most optimal compared to other types of polymers. This study examined the effect of irradiation duration and light intensity on Photosupercapacitor performance. The results showed that the length of light irradiation, photoelectric current (Isc) of DSSC (photosupercapacitor system) and capacitance (C) of Supercapacitor (photosupercapacitor system) had an exponential relation. Characterization of light intensity on photoelectric current (Isc) and potential difference (Voc) of DSSC (Photosupercapacitor system) had a linear relation. The same result also shown in the characterization of light intensity on potential difference (Vc) and capacitance (C) of Supercapacitor (Photosupercapacitor System) which produced linear relations.

Keywords
DSSC-Supercapacitor, Photosupercapacitor, TiO2, ZnO, PVDF,BaTiO3, Capacitance.

Topic
Renewable Energy

Link: https://ifory.id/abstract/ACK7m3NPuGvf

Corresponding Author
Putu Hadi Setyarini

Institutions
1Mechanical Engineering, Brawijaya University, Malang, Indonesia 65145
2Mechanical Engineering, Universitas Muhammadiyah Semarang, Semarang, Indonesia 50273
3Industrial Engineering, Brawijaya University, Malang, Indonesia 65145

Abstract
This research aims to determine the effect of adding filler material in the form of waste material on Nitrile Butadiene Rubber (NBR) in making roller rubber to improve quality in terms of hardness and tensile strength. Each rubber roller compound is made from a mixture of NBR with rice husk, waste rubber and wood charcoal. The test of hardness and tensile strength were done. The test results show that the addition of rice husk can increase hardness by 30% when compared to NBR without the addition of filler. While the value of tensile strength for NBR, and waste rubber alloys is much higher because this alloy is much more elastic.

Keywords
NBR, hardness, tensile strength, waste materials

Topic
Smart materials

Link: https://ifory.id/abstract/ZzLHK4yaqhdp

Corresponding Author
Priyo Agus Setiawan

Institutions
Shipbuilding Institute of Polytechnic Surabaya, Jalan Teknik Kimia Kampus ITS Keputih-Sukolilo Surabaya, Indonesia, 60111
Mechanical Engineering Department, Sepuluh Nopember Institute of Technology, Mechanical Engineering Department, Kampus ITS Surabaya, Indonesia, 60111
Center of Excellence in Automotive Control & System, Sepuluh Nopember Institute of Technology, Surabaya, Indonesia, 60111

Abstract
The hydrokinetic turbine is one of the renewable energy without generating emission impacted on environmental. In this work, the numerical simulation is used to investigate the influence of discretization along the blade surface towards the amount of the torque coefficient and power coefficient. This work will be done on Savonius hydrokinetic turbine numerically by using the Myring formula for n equal with 1 having the performance better than the conventional blade. This work will compare the performance among the blade discretization. Firstly, the numerical will be done the validation with experimental results at TSR of 0.8 and velocity of fluid kept constant at 0.22 m/s. Problem-solving uses Unsteady RANS with moving mesh for the rotating body. The turbulence model uses the Realizable k-epsilon (RKE) enhanced wall treatment with the discretization varied 800 and 1600. The layer number is 20 layers by varying the first layer on the blade surface of 1 and 1.2. This work focuses to obtain the torque coefficient and power coefficient. The results indicate that the increase of discretization on the surface of the blade has improved the accuracy results of the turbine performance.

Keywords
Savonius hydrokinetic turbine, myring formula, discretization, Realizable k-epsilon, turbine performance

Topic
Renewable Energy

Link: https://ifory.id/abstract/TpjgzEbauRUh

Corresponding Author
Irma kartika

Institutions
UM

Abstract
Carboxymethyl kappa-carrageenan (CMKC), is the result of carboxymethylation of kappa-carrageenan. Carboxymethylation of k-carrageenan is carried out in two stages: (1) Alkalization of k-carrageenan using NaOH, to form alkoxy-k-carrageenan, then etherification of alkoxy-k-carrageenan with monochloroacetic acid (MCA) as reactant to produce carboxymethyl k-carrageenan (CMKC). The success of CMKC synthesis can be measured based on the value of the degree of substitution, (DS), DS is the average number of hydroxyl groups that are converted to carboxyl groups. The success of the conversion of hydroxyl groups into carboxyl groups is influenced by several factors, synthesis temperature, types of reactants and the polarity of the reaction medium. This study has been done to analyze the effect of the polarity of the CMKC synthesis reaction medium,to the DS value. k-carrageenan was reacted with NaOH, then the results were reacted with monochloroacetic acid, insome variation proportion of isopropanol-ethanol-acetone, as reaction medium. The value of DS of CMKC that were synthesized was measured by the titrimetric method. The results showed that the polarity of the reaction medium affected the value of DS CMKC. The highest DS value (1,7) was owned by CMKC which was synthesized in the isopropanol-acetone-ethanol (25:3:2) v/v as reaction medium.

Keywords
carboxymethylkappa carrageenan, polarity, degree of substitution

Topic
Biomass, Biofuel

Link: https://ifory.id/abstract/hvBqLrGfE9CH

Corresponding Author
Sukarni Sukarni

Institutions
1 Department of Mechanical Engineering, State University of Malang, Semarang Street 5, Malang 65145, Indonesia
2 Centre of Advanced Materials for Renewable Energy, State University of Malang, Semarang Street 5, Malang 65145, Indonesia

Abstract
The prospect of microalgae Spirulina platensis-synthetic waste mixture (SPSW) as alternative energy to replace fossil fuels was investigated in term of the elemental composition changes during the combustion process. The microalgae Spirulina platensis (SP) sample was achieved from BBPBAP Jepara, Central of Java, Indonesia. While synthetic waste (SW) sample was taken from the temporary shelter in Malang City. A quantity of 30% of SP and 70% SW were mechanically mixed to warranty the uniform mixture in samples powder. SPSW sample was tested its chemical content by using Energy-dispersive X-ray (EDX). To understand the stage of thermal decomposition, the samples firstly were tested under the thermogravimetric (TG) instrument. The combustion has been performed at a heating rate of 10 oC/min at the temperature range of 25-1000 oC, under 100 ml/min constant flow rate of air atmosphere. From this experiments result could be specified the temperature of onset and end of the decomposition stage. In accordance with the temperature parameters, the new samples were heated up in the furnace with the similar TGs condition. The residuals left over at every stage then were analyzed their elemental composition to evaluate the changes of their content. The TG result showed that SPSW combustion occurred in &

Keywords
combustion; Spirulina platensis-Synthetic waste mixture; elemental composition

Topic
Biomass, Biofuel

Link: https://ifory.id/abstract/9FUeRD7xE8gJ

Corresponding Author
Atika Sari Puspita Dewi

Institutions
1Department of Physics, Faculty of Mathematics and Natural Science, Universitas Negeri Malang. Jl. Semarang 5 Malang, 65145 Indonesia
2Centre of Advanced Materials for Renewable Energy, Universitas Negeri Malang, Jl. Semarang 5, Malang 65145, Indonesia
3Department of Physics, Faculty of Mathematics and Natural Science, Universitas Airlangga. Jl. Semarang 5 Malang, 65145 Indonesia
4Department of Physics, Faculty of Science, National University of Singapore

*Corresponding Author : nandang.mufti.fmipa[at]um.ac.id

Abstract
Steam deposition techniques for fabricating CIGS (Copper Indium Gallium Diselenide) thin films require accurate environmental control and high costs, for which several alternative fabrication techniques have been developed. In this research the liquid phase method has been used with variations of decantation which will further affect the energy of the band produced. The CIGS film has been deposited on ITO (Indium Tin Oxide) substrate with doctor blade technique and XRD measurement which shows the resulting sample has a tetragonal crystal structure. SEM results show that the porosity of the film varies and the grain size of the CIGS increases with the number of decantation processes of oleylamine solvents. Band energy gap from CIGS decreases as oleylamin solvent decreases after the decantation process.

Keywords
CIGS, Doctor Blade, Decantation, Solar Cell

Topic
Renewable Energy

Link: https://ifory.id/abstract/fHhm7gK6nqLu

Corresponding Author
Muhammad Afnan Habibi

Institutions
(a) Universitas Negeri Malang
(b) Jacobs University

Abstract
Transformer had been widely used for supplying electric power to many motors, such as electric pumps, fans, or conveyors. The motor voltage may vary that is depending on its power and speed between one to another motor. The load needs the transformer which generate the proper voltage. Unfortunately, the working performance of transformer is decreasing because of its daily operation. In order to observe the working performance, the repetition of the transformer technical assessment is needed. This study provides the periodical inspection of high power transformer in maintenance and outage condition in the one of utility site in Indonesia. The checking activity maintains the eligible performance of the user device. The measurement of Sweep Frequency Response Analysis (SFRA) in the 5th unit had been done once in every six years. The measured result was obtained from 2007 until 2013. SFRA test diagnoses the characteristics of transformer winding and core by injecting low voltage at a certain frequency.

Keywords
SFRA, Transformer, Outage, Motor

Topic
Renewable Energy

Link: https://ifory.id/abstract/Dt6bfM2wunRa

Corresponding Author
Sukarni Sukarni

Institutions
Universitas Negeri Malang

Abstract
Abstract. This study aims to analyze the thermal characteristics of Tetraselmis chuii (T.Chuii) microalgae in the presence of TiO2 (Titanium dioxide). The experiment was carried out on thermal analyzer equipment under inert condition. The blended sample has a mass ratio of microalgae and TiO2 that was 10:0.03 (wt%). The results of the thermal analysis show that the addition of TiO2 can change the temperature characteristics during the reaction process. The Coats-Redfern method is applied to calculate activation energy (Ea) resulted in the value of the blended fuel in the second stage that was 56.9 kJ/mol lower than that of pure microalgae that was 70.68 kJ/mol and conversely in the third stage the value of activation energy for blended fuel was 264.57 kJ/mol higher than pure microalgae that was 223.25 kJ/mol. Overall results pointed out that TiO2 had a significant impact on the thermal characteristic of Tetraselmis chuii during the pyrolysis process.

Keywords
Keywords: earthenware ceramic, firing stove, heat waste

Topic
Biomass, Biofuel

Link: https://ifory.id/abstract/TPw932DpReEc

Corresponding Author
Ardianto Prasetiyo

Institutions
1Department of Mechanical Engineering, State University of Malang, Semarang Street 5, Malang 65145, Indonesia
2Master Program of Mechanical Engineering, Graduate School, State University of Malang, Semarang Street 5, Malang 65145, East Java Indonesia
3Centre of Advanced Materials for Renewable Energy, State University of Malang, Semarang Street 5, Malang 65145, Indonesia

Abstract
The investigation of Titanium dioxide (TiO2) nanoparticles on thermal characteristic of Tetraselmis chuii microalgae during combustion process has been carried out through a thermogravimetric (TG) analyzer. Tetrasemis chuii microalgae samples were cultured within 8 days at BBPBAP Jepara, Central Java, Indonesia. The microalgae sediment was dried at 80oC for 24 hours then was powdered by means of a mortar. Thereafter, the dried powder of microalgae was filtered with a size of 60 mesh. Titanium dioxide (TiO2) nanoparticles were used as catalysts with the particle size of 25 nm, these were obtained from Singapore Sigma Aldrich. Amount of 0.03 mg of TiO2 and 10 mg of Tetraselmis chuii microalgae were mixed mechanically using a mortar to guarantee the homogeneous blend, and then this sample was heated up in the oven for 14 hours at 80oC. The TG experiment was performed at a temperature range 25 to 900oC with atmospheric air at a flow rate of 50 mL/min and a heating rate of 15 oC/min. Differential method of Arrhenius is applied to evaluate kinetic parameters, including reaction order (n), activation energy (Ea), and pre-exponential factor (log A). The catalytic effect of TiO2 during the combustion process is compared with the pure of Tetraselmis chuii. The overall results of the investigation will be presented in the next full paper version

Keywords
Microalgae, Tetraselmis chuii, Titanium dioxide (TiO2), combustion

Topic
Biomass, Biofuel

Link: https://ifory.id/abstract/NrbzXBVvyKEx

Corresponding Author
Sukarni Sukarni

Institutions
Universitas Negeri Malang

Abstract

Keywords
Keywords: earthenware ceramic, firing stove, heat waste

Topic
Biomass, Biofuel

Link: https://ifory.id/abstract/YT68rQeF7ZWV

Corresponding Author
Aloon EKo Widiono

Institutions
a) Department of Mechanical Engineering, State University of Malang, Semarang Street 5, Malang 65145, Indonesia
b) Centre of Advanced Materials for Renewable Energy, State University of Malang, Semarang Street 5, Malang 65145, Indonesia
c) Master Program of Mechanical Engineering, Graduate School, State University of Malang, Semarang Street 5, Malang 65145, East Java Indonesia
*sukarni.ft[at]um.ac.id

Abstract
Abstract. This study aims to determine the thermal characteristics of microalgae Tetraselmis chuii pyrolysis in the presence of TiO2 using thermogravimetric analysis. The algae sample was harvested after 8 days of culture on a lab scale from Jepara, Central Java, Indonesia. Meanwhile, TiO2 material that was measuring of 25 nm was obtained from Singapores SIGMA ALDRICH. The washing of the sample was done twice using distilled water, and then the algae were deposited until formed the gel. Afterward, the gel material was heated for 24 hours at 80 C to obtain a dry form. Then the dry material was broken by crusher to be a powder and then filtered on a mesh of 60. The final sample was achieved by combining 10 mg of microalgae with 0.03 mg of TiO2. To ensure the homogenius blend, the mechanically mixing process was performed by using a mortar, and subsequently, the last heating was occupied on the sample at a temperature of 80 C for 14 hours. Experiments were carried out on TG analyzer (Mettler Toledo TG DSC 1). Approximately (10.03 mg) of the sample is placed in an aluminum pan and then inserted into the chamber. The heating process was initiated at a temperature of 25 C, and constantly controlled by a computer at the rate of 10 C min until the completed temperature of 900 C. To prevent the oxidation during the thermal processes, nitrogen is chosen as a carrier gas with a flow rate of 50 ml min. From the TG experiments subsequently could be determined the mass loss of the sample during the escalation temperature and time; therefore, the thermal decomposition behavior of the material is possible to be specified. From this thermal characteristic, then the reaction kinetics, as well as thermodynamic parameters, are evaluated. By using a single heating rate, it is practicable to determine of Ea (Activation energy), A (Pre-exponential factor), and n (reaction order) using the model-fitting of Coats-Redfern. These results will be compared with the kinetic of the parent Tetraselmis chuii and will be immediately presented in the next paper.

Keywords
Thermal Characteristics, Tetraselmis chuii, Pyrolysis, Titanium dioxide

Topic
Renewable Energy

Link: https://ifory.id/abstract/BPqWMQCXtxYK

Corresponding Author
Arramel Arramel

Institutions
1Surface Science Laboratory, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542

2 Energy Research Institute [at] Nanyang Technological University (ERI[at]N) 50, Nanyang Drive, Singapore 637553

3CINTRA UMI CNRS/NTU/THALES 3288, Research Techno Plaza, 50 Nanyang Drive, Level 6, Border X Block, Singapore 637553

4 Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 1176033

5Centre for Advanced 2D Materials (CA2DM) and
Graphene Research Centre (GRC), National University of Singapore, Singapore 117546, Singapore

Abstract
In this talk we will highlights our recent findings that essentially to achieve a superior physical performance of all-inorganic perovskites. Namely, two representative novel material such as bismuth-based ternary halide and cesium lead bromide have recently gained a lot of attention for an enhanced solar cell applications. However, photovoltaic performances of these devices remain poor, mostly due to their low-dimensional crystal structure and large bandgap. Here, a dynamic hot casting technique to fabricate silver bismuth iodide-based perovskite solar cells under an ambient atmosphere with promising power conversion efficiencies above 2.5% is demonstrated. In addition, Second part of the talk to investigate the interfacial nature across such heterostructures, high-resolution photoemission technique were employed. This work provides a new direction for fabrication of solution-processed lead-free perovskite solar cells with a rapid fabrication strategy irrespective of the processing environment.

Keywords
Perovskites, photovoltaics, x-ray photoemission spectroscopy, power conversion efficiency.

Topic
Smart materials

Link: https://ifory.id/abstract/9QfXWYCrtJ2V

Corresponding Author
Ardiansyah Rachmatdianto

Institutions
Electronic Engineering Polytechnic Institute of Surabaya

Abstract
Batteries are an important component in terms of electricity. It is undeniable that the need for batteries is a primary need at this time. The greater the voltage needed, the more batteries needed to generate electricity. Ultra Step Up converter is a series of dc to dc that can increase the DC energy source. The Ultra Step Up converter has the advantage of being able to increase the voltage with a large enough gain so that the voltage output value is very large with a small input voltage. In this final project Ultra Step Up converter will be developed with constant voltage regulation using Fuzzy Logic Controller. The DC battery source is 48V as input from the converter which will produce an output voltage that exceeds the boost converter output voltage. The advantage of Ultra Step Up Converter is that it can increase the voltage higher than conventional converters such as Boost Converter, and has good efficiency. Based on the simulation results show that the output voltage has reached the expected value of 540V with the initial ripple not too high with a duty cycle of less than 50%. To keep the output voltage constant, the Sugeno type fuzzy logic controller is used.

Keywords
Baterries, Fuzzy Logic Controller, Ultra Step Up Converter

Topic
Energy Storage

Link: https://ifory.id/abstract/e7K4Wbpk2VUQ

Corresponding Author
Gamar Basuki

Institutions
Electronic Engineering Polytechnic Institute of Surabaya

Abstract
Induction motors are AC electric motors are the most widely used. Induction motor speed control can be done with some type of converter. However, not all types of converters can produce a great efficiency in terms of induction motor speed control. Matrix converter with venturini modultion may be a suitable option for the efficient speed control system with scalar control. Modulation switching of matrix converter was designed by Venturini. Therefore in this study MATLAB Simulink simulations to test the use modulation on matrix converter switching is Venturini method. Given this research is expected induction motor speed regulation can be more efficient in its application in the industrial world.

Keywords
Induction motor, matrix converter, Venturini modulation

Topic
Renewable Energy

Link: https://ifory.id/abstract/T4cEnHbpXhdg

Corresponding Author
Gamar Basuki

Institutions
Electronics Engineering Polytechnic Institute of Surabaya

Abstract
Induction motors are AC electric motors are the most widely used. Induction motor speed control can be done with some type of converter. However, not all types of converters can produce a great efficiency in terms of induction motor speed control. Matrix converter with venturini modultion may be a suitable option for the efficient speed control system with scalar control. Modulation switching of matrix converter was designed by Venturini. Therefore in this study MATLAB Simulink simulations to test the use modulation on matrix converter switching is Venturini method. Given this research is expected induction motor speed regulation can be more efficient in its application in the industrial world.

Keywords
Induction motor, matrix converter, Venturini modulation

Topic
Renewable Energy

Link: https://ifory.id/abstract/FCHumk64Bp2J