Indonesia Conference Directory

Corresponding Author
Wahyu Aji Eko Prabowo

Institutions
(1) Informatics Engineering Department, Faculty of Computer Science, Universitas Dian Nuswantoro Semarang, 50131, Indonesia

(2) Catalysis and Reaction Engineering, Faculty of Industrial Technology, Institut Teknologi Bandung, Bandung, 40132, Indonesia

(3)Engineering Physics Department, Faculty of Industrial Technology, Institut Teknologi Bandung, Bandung, 40132, Indonesia

(4)Research Center for Nanoscience and Nanotechnology, Institut Teknologi Bandung, Bandung, 40132, Indonesia

(*) Corresponding author: prabowo[at]dsn.dinus.ac.id

Abstract
Molybdenum disulfide (MoS2) and nickel promoted MoS2 are increasingly used as catalyst in hydrotreating process, which involve adsorption, dissociation and formation of molecular hydrogen. This study aims at investigating the adsorption, dissociation and formation of hydrogen molecular over MoS2 and Ni promoted MoS2 (NiMoS) surface by using first-principles density functional theory (DFT). By using CI-NEB method, the activation energies of H2 dissociation and H2 formation are calculated. The most stable adsorption site is found in MoS2 surface. From the evaluation of H–H formation energy barrier on catalyst surface, NiMoS shows better reactivity than MoS2.

Keywords
Hydrogen, adsorption, dissociation, MoS2, NiMoS, density functional study

Topic
Theoretical and Analysis in Materials

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

Corresponding Author
Nadya Aryani Putri

Institutions
a)Departement of Metallurgy and Materials Engineering, Faculty of Engineering, Universitas Indonesia, Depok, 16424, Indonesia
b)Departement of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Depok, 16424, Indonesia
*sugeng[at]eng.ui.ac.id

Abstract
Titanium is classified as a bio-inert material, so it still does not support osseointegration when compared to bio-active material. This study aims to increase the surface roughness of Titanium, thus increasing the material osseoconductivity, because cells tend to stick and develop in materials with a more rough surface topography. In this study, anodized Ti-6Al-4V at 30, 50, 70, 120 V in H3PO4 and H2SO4 electrolyte, both in concentration of 0.5 and 1 M was successfully prepared to evaluate the effect of parameters applied and its kinetic aspect to the color oxide film, surface roughness and using SEM-EDS, Accretech Surfcom 2900SD3, and scriber. The results show an increase in surface roughness with the increase of voltage and electrolyte concentration because of the surface texture in the form of valleys and peaks. Moreover increasing the voltage will thicken the oxide layer, and changing the color produced. Meanwhile the higher the concentration of the electrolyte will relatively makes the oxide layer less thick. The composition of the oxide layer shows incorporation of Phosphorus and Sulfur ions in both electrolyte, and the results of the scratch resistance test do not show any cracks.

Keywords
Anodizing, Surface Roughness, Ti-6Al-4V, Colored Oxide Film

Topic
Theoretical and Analysis in Materials

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

Corresponding Author
Intan Masruroh S

Institutions
Universitas gadjah mada

Abstract
Ferroelectric material has been used for advanced semiconductor technology. A necessity of a better processing instruments increased every year. Spintronics material as perovskite (PbTiO_3 and BaTiO_3) become new approach in processing instruments because of their ferroelectricity. This paper describes a new study of structure and electronic system perovskite. The ferroelectricity and spin splitting material influence energy and structure in momentum space. The spin splitting in this material proved by Rashba parameter.

Keywords
Spintronics, ferroelectric, spin splitting

Topic
Theoretical and Analysis in Materials

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

Corresponding Author
Nikodemus Umbu Janga Hauwali

Institutions
Physics for Electronic Material Research Division, Department of Physics
Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology

Abstract
A first principles study with density functional theory method has carried for parallelogram graphene nanoflakes. In this work, we used ABINIT package to calculate the fundamental properties of parallelogram graphene nanoflakes in armchair and zigzag types, due to the increase of the number of atoms. The effect of defect for these characters in each type is also presented. Depend on the calculation results, the bandgap of parallelogram graphene nanoflakes only exists in armchair types with largest bandgap 0.021 eV for 54 atoms, while the zigzag types have no bandgap. Based on these results, it can be said that the properties of parallelogram graphene nanoflakes is semimetal. In addition, the density of states results shows that the magnetic properties of parallelogram graphene nanoflakes is non-magnetic since the symmetrical properties between density of states in spin up and spin down. Based on the results study of defect effect, it was found that the defect only affected the bandgap, but not the magnetic properties.

Keywords
parallelogram graphene nanoflakes, density functional theory, bandgap, density of states

Topic
Theoretical and Analysis in Materials

Link: https://ifory.id/abstract/2aGNcqkL7Bjd

Corresponding Author
Fanny Arviani Roseno

Institutions
a) Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia
*sugeng[at]eng.ui.ac.id

b) Department of Metallurgy and Materials Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia

c) Center for Science and Technology for Advanced Materials, BATAN-Indonesia

Abstract
In this study, fabrication process of Ti6Al4V implant material was developed using powder metallurgy. However, due to the high reactivity of titanium with oxygen at high temperature during sintering, TiO2 layer, which is excellent to corrosion resistance loses its protective properties and allows oxygen to diffuse into the bulk of material. This phenomenon is commonly undesirable because it can be detrimental which decreases the quality of material bonds and mechanical properties that causes brittle material. The Arc Plasma Sintering (APS) method was used to protect the material from the formation of an oxide layer (TiO2) on the Ti6Al4V surface and protects from oxygen diffusion. Sintering process was investigated using a new technology of Arc Plasma Sintering (APS). This sintering technology is carried out using both currents and plasma as a heat source which is capable of performing the sintering process with a very short time in just minutes, and low energy consumption. Sintering was performed on 50 A currents with variations in sintering time for 4 minutes, 8 minutes and 12 minutes. The results of the Arc Plasma Sintering (APS) process were compared to sintering using argon atmosphere at a temperature of 1300oC for 2 hours, 3 hours and 4 hours. The material characterization was performed using SEM-EDS and XRD. The density and hardness testing were measured between two methods of Arc Plasma Sintering (APS) and argon sintering. The results of this study indicate that with the Arc Plasma Sintering (APS) method, the material has better density and hardness with a relative density value of 98.40%, hardness value of 375 HV, and the thickness of the TiO2 surface layer continues to decrease from 16.4 µm to 12 µm without any diffusion of oxygen into the material when compared to argon sintering.

Keywords
Ti6Al4V, High Temperature, Arc Plasma Sintering, Oxidation, TiO2 layer

Topic
Theoretical and Analysis in Materials

Link: https://ifory.id/abstract/Kg47urDQRfhb

Corresponding Author
Muhammad Anshory

Institutions
(a) Departement of Physics, Universitas Gadjah Mada, Sekip Utara BLS 21, Yogyakarta 55281, Indonesia
*adib[at]ugm.ac.id
(b) Research Center for Physics, Indonesian Institute of Sciences (LIPI), Tangerang Selatan 15314, Indonesia

Abstract
Recently, two-dimensional (2D) materials have been studied due to its unique properties and potentials for electronic devices. Tin Selenide (SnSe) is a promising material to be developed in many fields by identifying its electronic structure. In this study, we investigate the effect of layer-dependent electronic properties of SnSe using first-principles calculations based on density functional theory (DFT). We firstly optimized layer dependent of the lattice constant and atomic distortion and then calculate the electronic structure-related parameter including band structure and density of electron (DOS). We find that the calculated band gap decreases with increasing the layers of SnSe which is not dependent on fully relativistic calculation by turning spin orbit coupling (SOC). However, we identify substantial spin splitting in the band structure under the presence of the SOC, making this multilayer is promising for spintronics.

Keywords
SnSe; spin splitting; layer-dependent; density-functional theory

Topic
Theoretical and Analysis in Materials

Link: https://ifory.id/abstract/bVyRtn9HN8CE

Corresponding Author
Ibnu Syuhada

Institutions
a) Department of Physics, Institut Teknologi Bandung, Physics of Electronic Materials Research Division, PECVD Lab. Ganesha 10, Bandung 40132, Indonesia

* toto[at]fi.itb.ac.id

Abstract
In this recent work, we develop new empirical interatomic potential for the construction of carbon materials. We started by expressing an explicit form of incorporate energy and the local environment to redefine bond order, allowing increased accuracy of computation to be realistic. As a result, we show comparisons of calculations with experiments and other methods for cohesive energy, bond length, mechanical properties, including phonon. The work limitations are also discussed for future use.

Keywords
bond order, empirical interatomic potental, local environment

Topic
Theoretical and Analysis in Materials

Link: https://ifory.id/abstract/vK6YPrMXRpQD

Corresponding Author
Sutikno Madnasri

Institutions
1,4,5) Department of Electrical Engineering, Dian Nuswantoro University, Semarang, Indonesia
2,3) Advanced Composite Laboratory, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang

Abstract
The new Electronic nose (enose) instrument is able to detect diseases through aroma blood, secret, stool, breath and urine. Scientists in the world develop enose for early detection of diabetes mellitus (DM). They developed a device and an enose recognition algorithm. Enose is an instrument consisting of hardware and software that contains a pattern recognition algorithm (PARC-Pattern Recognition). The instrument is able to provide decisions in realtime, sensitive to aroma changes and portable. A large number of e-nose instruments, based on a variety of technologies and operational mechanisms, are available for early detection of diabetes mellitus. Some of the common enose technologies used are polymer sensors (CP), metal-oxide semiconductors (MOS), and nano particles. The E-nose device is useful in designing portable and mobile technology as a remote monitoring tool for patients who require intensive control instulin. This article is a recent system review and enose algorithm, developed over the past decade, which has potential applications for early detection of diabetes mellitus. This article discusses a review of the development of enose for early detection of diabetes, starting from the use of the type of sensor, comparison of the number of sensors, the use of feature characterization methods, feature matrix, feature extraction methods and pattern recognition methods.

Keywords
Review, diabetes detection, enose

Topic
Theoretical and Analysis in Materials

Link: https://ifory.id/abstract/FdZnRQckarX8

Corresponding Author
Sutikno Madnasri

Institutions
1,4,5) Department of Electrical Engineering, Dian Nuswantoro University, Semarang, Indonesia
2,3) Advanced Composite Laboratory, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang

Abstract
The need for aroma recognition devices or often known as enose (electronic nose) is increasing. In the field of health, enose is able to detect early type 2 diabetes mellitus (DM) from urine aroma. Enose is an aroma recognition tool that uses a pattern recognition algorithm to recognize urine aromas from diabetes mellitus patients based on input signals from gas sensor arrays. The need for portable enose devices is increasing, because of the increasing need for real-time needs. This has a large impact on the selection of the number of gas sensor arrays in the enose. This article discusses the effect of the number of sensor arrays used on the results of the introduction. Enose uses a maximum of 4 sensors, with a maximum feature matrix. After that, the characteristic matrix enters the feature extraction of PCA (Principle Component Analysis) and clustering using the FCM (Fuzzy C Means) method. Variations in the number of sensors consist of 1 sensor, 2 sensors, 3 sensors and 4 sensors. The sensor used consists of MQ2, MQ5, MQ6 and MQ8. The results of the introduction show that, enose using 2 sensors has a high accuracy of 98.3%.

Keywords
number of sensor arrays, MQ sensors, enose

Topic
Theoretical and Analysis in Materials

Link: https://ifory.id/abstract/N6nJfcRVrP3L

Corresponding Author
Sutikno Madnasri

Institutions
1,4,5) Department of Electrical Engineering, Dian Nuswantoro University, Semarang, Indonesia
2,3) Advanced Composite Laboratory, Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang

Abstract
Aroma based electronic nose recognition instrument develops for medical needs. This instrument is expected to be able to detect diseases in the body, through urine, blood, breath, sketch, sweat and human feces. This is a new challenge for instrument enose, especially for recognizing type 2 diabetes mellitus (DM). Some previous studies applied statistical methods using the time domain, such as using maximal, minimal, standard deviation, variance and means. Each sensor uses only 1 statistical feature. Enose has not used more than 1 statistical feature. This article discusses the effect of the number of features included in the process of recognition of the results of the introduction. Enose uses 4 polymer gas sensors, then calculates the statistical characteristics of the changes in the gas sensor resistance. This results in a feature matrix. The next process is calculating feature extraction using the PCA (Principle Component Analysis) method and clustering using the FCM (Fuzzy C Means) method of the feature matrix. Enose uses characteristic variations ranging from 2 traits, 3 traits, 4 traits and 5 traits. The results of the introduction show that, enose using 3 characteristics has a high accuracy of 83.3%.

Keywords
characterization, statistical characteristics, enose

Topic
Theoretical and Analysis in Materials

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

Corresponding Author
Yedija Yusua

Institutions
(a) Department of Physics, Universitas Gadjah Mada, Sekip Utara BLS 21 Yogyakarta,
55281 Indonesia
*adib[at]ugm.ac.id

Abstract
The electronic structure of bulk Hybrid Organic-Inorganic Perovskite (HOIP) CH3NH3PbX3 (X = Br and Cl) has been investigated using a computational method based on Density Functional Theory (DFT). The investigation demonstrates that spin splitting is found when a favoured orientation of organic cation is aligned along the [111], the [101] and the [011] directions. We show that Rashba splitting is induced with the anisotropical character of spin polarization in [111] directions, whereas the unidirectional out-of-plane of spin polarizations are achieved in [011] and [101] directions. By employing k ⃗∙p ⃗ perturbation theory based on symmetry consideration, we find a large spin-orbit strength from these splitting. These findings show that the bulk HOIP CH3NH3PbX3 is a promising material for the development of perovskite-based spintronic devices.

Keywords
First-Principles Calculations, Spin-Orbit Interaction, Spintronics, Condensed Matter and Materials Physics

Topic
Theoretical and Analysis in Materials

Link: https://ifory.id/abstract/aNj89EkMwtqy