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ANALYSIS OF THE EFFECT OF STUART NUMBER AND RADIATION ON VISCOUS FLUID FLOW Anggriani, Indira; Norasia, Yolanda; Tafrikan, Mohamad; Ghani, Mohammad; Widodo, Basuki
Journal of Fundamental Mathematics and Applications (JFMA) Vol 7, No 1 (2024)
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jfma.v7i1.22481

Abstract

Computational fluid dynamics (CFD) is a numerical solution of fluid flow problems built from applied mathematical modeling. The problem of the flow of a viscous fluid which is influenced by a magnetic field gives rise to a boundary layer, from this boundary layer a dimensional building equation is formed. The governing equation is obtained from the continuity equation, momentum equation, and energy equation, then transformed into a non-dimensional equation by substituting non-dimensional variables and transformed into a similarity equation. The numerical solution to this problem uses the Keller Box method. The numerical simulation results show that the Stuart Number increases the velocity profile, while the temperature profile decreases. The effect of radiation parameters on the velocity profile did not change significantly, but the temperature profile decreased.
UTILIZATION OF VOLUME COMPOSITE FRACTION IN KEPOK BANANA STEM (MASSA PARADISIACA) RANDOM CORNER ORIENTATION WITH POLYESTER MATRIX AGAINST THE MECHANICAL CHARACTERISTIC Widodo, Basuki; Subardi, Anang
Journal of Sustainable Technology and Applied Science (JSTAS) Vol. 1 No. 1 (2020): Journal of Sustainable Technology and Applied Science, May 2020
Publisher : Lembaga Penelitian dan Pengabdian Masyarakat, Institut Teknologi Nasional (ITN) Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36040/jstas.v1i1.2611

Abstract

This study aims to determine the effect of volume fraction (10%, 20%, 30%, 40%, 50%) of composite banana stem fiber with polyester matrix on tensile strength and impact strength. From the results of the study obtained an average strength value the most optimal tensile is found in the 10% fiber volume fraction and 90% matrix that is 51.863 N/mm2 and strain value 5.754 N/mm2. As for the lowest tensile strength at 20% fiber volume fraction and 80% matrix that is 36.356 N/mm2 and strain value 7.796%. The composite which has the highest average energy and impact value is the 50% volume fraction matrix 50% has an absorption rate with an average absorbed energy value of 0.8093 Joules and an average Impact Price of 0.0101 Joules / mm2, while the lowest in the volume fraction of 20%, 80% matrix with an average energy value of 0.4129 Joules and an average Impact Price of 0.0052 Joules/mm2. It can be concluded that the addition of fiber volume fraction affects the tensile strength and impact strength.
ADDITION OF MAGNESIUM (Mg) WITH ALUMINA (AL2O3) REINFORCER IN ALUMINUM MATERIAL COMPOSITES ON THE MECHANICAL PROPERTIES AND MICRO STRUCTURES Widodo, Basuki; Sasmito , Agung Panji
Journal of Sustainable Technology and Applied Science (JSTAS) Vol. 2 No. 2 (2021): Journal of Sustainable Technology and Applied Science, November 2021
Publisher : Lembaga Penelitian dan Pengabdian Masyarakat, Institut Teknologi Nasional (ITN) Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36040/jstas.v2i2.4159

Abstract

Aluminum is a widely used and applied material in daily life or in the industrial and automotive world. In order to improve the performance and properties of the application to be used, it needed an alloying element to improve the mechanical properties of the aluminum. Aluminum Matrix Composite (AMC) or better known as aluminum matrix composite is one type of material that has great potential to be developed, due to its good combination and properties such as high strength and hardness, low density, low density, capable of good machining, and its basic ingredients are easily found on the market and cheaper than other materials. This research was conducted using the stir casting process to be able to mix all the compositions contained in aluminum matrix composites and to help the distribution of alumina reinforcing particles (Al2O3) and aluminum matrices be evenly distributed. The parameters used in this casting process are varying the volume fraction of the Al2O3 amplifier by 0.5%; 1.5% and 2.5% plus the magnesium content remains 0.9%. The results showed that the addition of Al2O3 can increase the value of hardness and reduce the value of tensile strength. The highest hardness value was 75.3 HRB at the addition of Al2O3 by 2.5% and the lowest tensile strength value was 7.17 Kgf / mm2 with the percentage of Al2O3 addition of 0.5%.
STIR CASTING METHOD ON ALUMINA (Al2O3) COMPOSITE MATRIX WITH SiC STRENGTHEN AND MAGNESIUM (Mg) ADDITION TO MICROSTRUCTURE AND MECHANICAL PROPERTIES Widodo, Basuki; Wahyu Panji Asmoro; Amirullah Firmansyah
Journal of Sustainable Technology and Applied Science (JSTAS) Vol. 3 No. 2 (2022): Journal of Sustainable Technology and Applied Science, November 2022
Publisher : Lembaga Penelitian dan Pengabdian Masyarakat, Institut Teknologi Nasional (ITN) Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36040/jstas.v3i2.4160

Abstract

Aluminum is a material that has the ability as a material that is widely used because of its light weight, good corrosion resistance, good appearance, reliable electrical conductor, good electricity conductor, and several other advantages of this material. The development of aluminum (Al) material in the form of aluminum matrix composite (AMC) is often applied in various fields including automotive, industry, military, and aviation. The reinforcing particle that is often used in AMC is silicon sarbide (SiC) to improve the properties of AMC. The addition of magnesium (Mg) is useful as a wetting agent for reinforcing particles and matrices. This study aims to determine the effect of adding magnesium (Mg) on the mechanical properties and microstructure of the aluminum matrix composite 1100 series reinforced with silicon carbide (SiC) using the stir casting method. The reinforcing silicon carbide (SiC) particles were added to the aluminum matrix composite (Al) by 5%. The variations in the addition of magnesium were 0.75%, 1.25%, and 1.75% as wetting agents. To find out the mechanical properties, this research was carried out by testing the tensile strength and hardness. The hardness test results showed the highest hardness in the magnesium (Mg) 1.75% variation of 84.67 HRB and the highest tensile strength in the pure aluminum (Al) variation of 9.41 Kgf/mm2.
Tantangan dan Peluang Pendidikan Matematika di Era Masyarakat Ekonomi Asean (AEC) Widodo, Basuki
Prosiding Konferensi Nasional Penelitian Matematika dan Pembelajarannya 2019: Prosiding Konferensi Nasional Penelitian Matematika dan Pembelajarannya
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3306.818 KB)

Abstract

(ASEAN Economic Community)Pasar Bebas ASEAN sangat Memungkinkan akan Mudahnya Mobilitas Barang, Jasa, Dan Orang Antarnegara Di Wilayah ASEAN Free flow of goodsFree flow of servicesFree flow of investmentFree flow of capitalFree flow of professionals and skilled labours Akan tetapi ada tantangan tersendiri yaitu Munculnya Kegagapan Massal Terutama Bagi Angkatan Kerja Yang Tidak Terdidik Dan Tidak Terlatih
MAGNETOHYDRODYNAMICS NANOFERRO FLUID FLOWS PASSING THROUGH A MAGNETIC POROUS SPHERE UNDER THERMAL RADIATION EFFECT Widodo, Basuki; Pamela, Eirene Juwita Ningtyas; Adzkiya, Dieky; Imron, Chairul; Rahayuningsih, Tri
BAREKENG: Jurnal Ilmu Matematika dan Terapan Vol 16 No 4 (2022): BAREKENG: Journal of Mathematics and Its Applications
Publisher : PATTIMURA UNIVERSITY

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (456.749 KB) | DOI: 10.30598/barekengvol16iss4pp1303-1312

Abstract

In the application of thermonuclear reactor cooling, temperature regulation relies on experiments based on practical experience. Therefore, the accuracy of this temperature setting is operator-dependent. So it is necessary to develop a mathematical model to solve these problems. The dimensional mathematical model therefore is generated using the conservation laws of mass, momentum, and energy. The dimensional mathematical model is further transformed into non-dimensional mathematical model by using non-dimensional variables. The non-dimensional mathematical model is simplified using the similarity equation by utilizing the stream function. The model obtained is a system of nonlinear ordinary differential equations. This system of equations is then solved using an implicit numerical method using Keller-Box scheme. This Keller-Box method has high accuracy and is more efficient. The numerical simulation results show that the velocity profile and temperature profile decrease as the magnetic parameter, porosity parameter, and the Prandtl number increases, respectively. Meanwhile, when the radiation parameter increases, the temperature profile also increases, but the radiation parameter does not affect the velocity profile.
Optimal Control and Model Analysis of The Spread of Pneumonia in Toddlers in East Java-Indonesia Using The Pontryagin’s Minimum Principle Widodo, Basuki; Kamiran, Kamiran; Syahputri, Denisa Dwi
Jambura Journal of Biomathematics (JJBM) Volume 6, Issue 3: September 2025
Publisher : Department of Mathematics, Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37905/jjbm.v6i3.31974

Abstract

Pneumonia is  a  type  of  acute  respiratory  infection   (ARI) that  attacks  the  lungs and  is  caused   by  various microorganisms, such  as bacteria, viruses, parasites,  fungi, exposure to chemicals, or physical damage  to the lungs. Pneumonia is  included in  the list  of  10 diseases  with  the highest  number   of  cases  according to the Indonesian Ministry of Health reported  in April 2023. Pneumonia is the biggest cause of death in toddlers  aged 12-59  months,  reaching  12.5%. Therefore,   to  reduce  the  spread   of  pneumonia,  this  research  will  discuss providing  optimal control using the mathematical model  of  SEIR (Susceptible-Exposed-Infected-Recovered). The model  used is a pneumonia spreading model  with  implementing control in the form of first stage treatment and second  stage treatment. The results  of the stability analysis show  that at the disease-free  equilibrium point and  the endemic  equilibrium point,  the system  is  stable  respectively. Based  on  controllability analysis, it  is obtained  that the system  is controlled so that the system  can be controlled. In addition, based on the results  of the analysis of the optimal control  problem  with  Pontryagin’s Minimum Principle simulated with  Runge Kutta order  4, it shows  that the first  stage of treatment control  (u1)  and  the second  stage of treatment  (u2)  are very effective   in   reducing  the  number   of  individuals  infected   with   mild  pneumonia and   severe   pneumonia respectively.