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Contact Name
Heru Suryanto
Contact Email
jmest.journal@um.ac.id
Phone
+62341588528
Journal Mail Official
jmest.journal@um.ac.id
Editorial Address
3rd floor of H5 Bulding, Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Malang Jl. Semarang 5 Malang, Jawa Timur, 65145 Telp 0341-588528 / 0341-551312 ext 298
Location
Kota malang,
Jawa timur
INDONESIA
Journal of Mechanical Engineering Science and Technology
ISSN : 25800817     EISSN : 25802402     DOI : 10.17977
Journal of Mechanical Engineering Science and Technology (JMEST) is a peer reviewed, open access journal that publishes original research articles and review articles in all areas of Mechanical Engineering and Basic Sciences
Articles 96 Documents
Backpack Effects on Two-Dimensional Gait Spatiotemporal and Kinematic Parameters Nardo Rizaldy; Alvin Alvin; Wirawan Lingga; Ethan B.W. Goeij; F. Ferryanto
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 6, No 2 (2022)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v6i22022p057

Abstract

Loads could affect the body gait in various ways. Backpacks, sling bags, suitcases, and even trolleys could hugely affect human gait without us realizing it. The effects of these loads have been scientifically researched in biomechanics and sports science for the past few years. For instance, the comparison of walking with and without a backpack could easily reveal significant differences in body segments, which could be utilized for therapy and medicine development. The aim of this research is to determine the differences of the spatiotemporal kinematic parameters between a conventional human gait and a backpack-loaded gait. Some parameters to be highlighted are stride lengths, stride duration, joint angles, linear and angular segment positions, velocities, and accelerations. The method used for marker data acquisition is based on the 2-dimensional Direct Linear Transformation. The results demonstrate that the backpack increases stride lengths and reduces stride duration, contrast to the expected where backpacks would reduce stride lengths. It was observed that the angle between the bag and the body posterior affects the abdomen relative angle, which directly translates to stride lengths as well. During unloaded walking, increases in pelvic rotation contribute to increases in stride length with increasing walking speed. However, in loaded walking, the back angle is also a factor in determining kinematic parameters.
The Effect of Nozzle Temperature, Infill Geometry, Layer Height and Fan Speed on Roughness Surface in PETG Filament Doohan Taqdissillah; Aris Zainul Muttaqin; Mahros Darsin; Dedi Dwilaksana; Nasrul Ilminnafik
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 6, No 2 (2022)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v6i22022p074

Abstract

3D printing is a process of making three-dimensional solid objects from a digital file process created by laying down successive layers of material until the object is created. Many filaments can be used in 3D printing, one of which is PETG (PolyEthylene Terephthalate Glycol). PETG is a modification of PET (PolyEthylene Terephthalate) with added glycol at a molecular level to offer different chemical properties that provide significant chemical resistance, durability, and excellent formability for manufacturing. This study aims to find the most optimal parameter of surface roughness of PETG with different parameters of nozzle temperature, infill geometry, layer height and fan speed. Taguchi L16 (44), with four levels for each parameter, was used to determine the effect of each parameter. Each experiment was repeated five times to minimize the occurrence of errors. Based on the result, the effect of each parameter is nozzle temperature at 4.9%, infill geometry at 5.9%, layer height at 82.3%, and fan speed at 4.6%. Layer height has the highest effect on surface roughness, and other parameters have a low effect, under 7%. Research shows that the optimal combination of parameters is a nozzle temperature of 220 °C, infill geometry zig-zag, layer height of 0.12 mm, and a fan speed of 80 %.
Mechanical Properties of Biocomposite with Various Composition of CaCO3 and Starch Agris Setiawan; Fransisca Diana Wahyuningsih; Riria Zendy Mirahati
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023001

Abstract

Calcium carbonate has the potential to be used in the development of medical materials, including biomaterials. Biocomposite is composed of CaCO3 as matrix material and bioplastic from the combination of corn starch and cassava starch as reinforcement. This study aims to determine mechanical properties such as tensile strength and bending/flexural strength with varying compositions of CaCO3 and bioplastic. Characterization of the biocomposite uses Scanning Electron Microscope to observe the microstructure and composition elements of their structure. This study used 4 variations in the ratio of CaCO3 suspension: (Corn Starch + Cassava Starch). Each sample was characterized using specimen code A for composition 30:70 (w/w) percent and specimen B for composition 40:60 (w/w) percent, specimen C for composition 50:50 (w/w) percent, and specimen D for composition 60:40 (w/w) percent. Based on the results of shrinkage measurements on flexural strength specimens, specimen B has the lowest percentage value of 15±0.01 percent. The lowest tensile strength specimen is found in specimens C and D at 12±0.01 percent. The tensile test results also showed that specimen D had a higher ultimate strength value than the other specimens, which was 0.06±0.03 MPa. Microstructure characterization was carried out using scanning electron microscopy with energy-dispersive X-ray spectroscopy, which revealed the presence of Oxygen at approximately 48.39 percent mass, Carbon at approximately 30.27 percent mass, Nitrogen at approximately 11.77 percent mass, Calcium at approximately 9.57 percent mass, with Calcium being detected in the form of Calcium Carbonate (CaCO3).
Effect of Grafting Nano-TiO2 on Sansevieria cylindrica Fiber Properties Chrisrulita Sekaradi Wiguna; Heru Suryanto; Aminnudin Aminnudin; Joseph Selvi Binoj; Alamry Ali
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023010

Abstract

Natural fibers, which are abundant, environmentally friendly, and biodegradable, are used as a replacement for synthetic fibers. The composite strength can be increased by treating the surfaces of natural fibers with suitable chemicals, which can also improve the interface interaction between fiber and matrix. Application of a coupling agent in chemical treatment is utilized to reinforce the bonding between fiber and matrix. The objective of the study is to determine the influence of silane concentration on the Sansevieria cylindrica fiber properties. The methods included fibers treatment using ethanol and coupling agent as dissolving and TiO2 with concentrations of 0 percent, 0.25 percent, 0.5 percent, 0.75 percent, and 1 percent. The mechanical strength testing was conducted through a single fiber test. Fiber morphology was observed using an electron microscope. FTIR analyzes the change in fiber chemical composition caused by TiO2 addition. As a result, the morphology of S. cylindrica fibers became rougher and showed a rougher surface after a silane concentration of 1 percent, but with the proper concentration, some fiber surfaces provided a good interface. Ti-O bonds are formed at a wavelength of 475 cm-1. The shift in a peak at 400–500 cm-1 indicates Ti-O-Ti group stretching vibrations believed to have originated from TiO2 particles. The mechanical strength increases as the concentration of TiO2 increases, with the highest fiber strength of 284.66 MPa observed at a TiO2 concentration of 1 percent. This represents a 26 percent higher tensile strength compared to the control specimen.
Synthesis and Characterization of Nitrogen-Doped Activated Carbon for Lithium Battery Anode Applications Prihanto Trihutomo; Poppy Puspitasari; Muhammad Bustomi Radja; Milzam Rahmat Busono
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023p020

Abstract

Nitrogen-dopped activated carbon was synthesized to see its effect on the characterization of the nitrogen surface functional groups, crystal size, and morphology of the resulting sample. Synthesis of nitrogen-doped activated carbon was carried out by varying the addition of Urea as a nitrogen doping source. Activated carbon compared its characteristics with variations in the concentration of added Urea to activated carbon, at 1:3 and 1:5. The FTIR results obtained were the presence of functional groups indicating the presence of nitrogen bonds in each sample. The crystallinity results showed that the samples were classified as crystalline and nitrogen doping influenced the size of the crystallinity of each sample. The morphology of nitrogen-doped activated carbon shows differences in the grain size of nitrogen-doped activated carbon. Crystallinity and morphology have been shown to affect battery anode performance. The more crystalline of anode material, the electrochemical properties are better. The smaller the grain size of the sample morphology, the stability of the battery cycle is to be great.    
The Combustion Characteristics of Calophyllum inophyllum Fuel in the Presence of Magnetic Field Imam Rudi Sugara; Nasrul Ilminnafik; Salahuddin Junus; Muh Nurkoyim Kustanto; Yuni Hermawan
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023p028

Abstract

The study objective is to investigate the combustion characteristics of Callophyllum inophyllum fuel in presence of a magnetic fields. To conduct the experiment, a bunsen burner was utilized, with fuel and air being dispensed via a syringe pump and compressor, both regulated by a flowmeter. The fuel and air pipes were heated to 532.15 (K) to facilitate fuel evaporation. The equivalent ratio of 0.5, 1, and 1.5 was adjusted to control air discharge and fuel. An 11,000 gausses artificial magnet was used, with N-S, N-S, N-N, and S-S being the various magnetic pole configurations. The study found that the magnetic field can enhance combustion quality by affecting the molecules involved in the combustion process. The magnetic field's force also intensifies the movement of O2, making it more energetic. As O2 travels from the North Pole to the South Pole through the combustion reaction zone, it quickens the oxidation-reduction process and curtails diffusion combustion. The red color's intensity diminishes with the magnetic field's effect, indicating this phenomenon. When a magnetic field is applied, the polarity of C.inophyllum biodiesel fuel becomes highly favorable. The triglyceride carbon chain bonds become unstable, and the van der Walls dispersion forces are weakened, which facilitates easier O2 binding to the fuel, resulting in more efficient combustion. An increase in the laminar burning velocity value can be noticed when exposed to a magnetic field.
Effect of Current and Pulse-on Time on Material Removal Rate and Surface Roughness of Tungsten Carbide in Electric Discharge Machine Die-sinking Mochammad Deny Riyanto; Andoko Andoko; Heru Suryanto
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023p039

Abstract

The focus of manufacturing for tungsten carbide applications often demands a smooth surface quality as the result of the Electric Discharge Machine (EDM) die-sinking process, especially in the manufacture of die and mold with tungsten carbide material processed using a die-sinking EDM machine. The purpose of this study is to analyze the effect of electric current and pulse-on time on the Material Removal Rate (MRR) and surface roughness of tungsten carbide. Through the experimental method, the parameters varied, namely electric current 17 A, 20 A, 23 A, and pulse-on time 30 µs, 55 µs, and 80 µs. MRR was calculated through weight loss. Surface roughness was obtained from a surface roughness tester and a Scanning Electron Microscope for surface morphology. The results showed that the highest material removal rate was 1.509 mm3/min at 23 A and 30 µs, and the lowest material removal rate was 0.262 mm3/min at 17 A and 80 µs. The highest surface roughness value was 4.278 µm at 23 A and 80 µs. The lowest surface roughness value was 2.166 µm at 17 A and 30 µs. The tungsten carbide surface topography results are crater, globule, crack, and porous. The greater the current used, the higher the MRR value and surface roughness. Meanwhile, the greater the pulse-on time used, the MRR value decreases, and the surface roughness increases.
Lap Joint on St.37 Steel Plate with Friction Welding Clamping Method Widia Setiawan; Nugroho Santoso; Wiyadi Wiyadi; Muhammad Sulistiyo Aji; Rachmat Alamin; Achsan Tarmudi
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023p047

Abstract

Friction stir (FW) welding is a relatively fresh method that was created and has been continually refined and adapted to industrial applications due to its benefits. This approach for solid-state joining entails connecting the components at a temperature below their melting point and then heating them up. Clamp joint applications are widely used using external heating and hitting with high strength, but the clamped joints with the FW method are rarely done. The research studied the characteristic of clamped joints at various plate thicknesses using the FW method. In this study, 30 specimens were used in the form of a St.37 low carbon steel plate with a size of 50 mm x 100 mm and a thickness of 3 mm, 5 mm, and 9 mm, and several holes were made with a diameter of 5 mm. The plate was connected by 2 clamps, and 4 clamps then the FW method was conducted in a milling machine. The results indicate that the plates were connected well. The highest hardness value was 256.4 VHN on the FW of 9 mm plate. The microstructure is dominated by ferrite and a little pearlite phase. The largest shear force is 66.54 kN obtained at 4 clamps with a plate thickness of 9 mm, and the lowest is 13.46 kN, obtained at 2 clamps with a plate thickness of 3 mm.
The Effect of Cutting Speed of Nitrogen Laser Cutting on the Surface Texture of SUS 304 Plate Yanuar Rohmat Aji Pradana; Raka Afrianto; Chandra Hairat Abdul Rahman; Andoko Andoko
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023p066

Abstract

The focus of today’s machining industry is on how to maintain high productivity and low cost achieved by high tool life during the operation. Laser cutting is considered the right solution because it offers cutting speeds of up to 170000 mm/min through a non-contact process regardless of the workpiece material hardness. The aim of this study is to analyze the effect of cutting speed on the surface texture aspects namely surface roughness, kerf shape, and dross height on the stainless steel 304 plate after laser cutting. The nitrogen laser was utilized with the cutting speed of 400, 1700, and 2000 mm /min and the average roughness (Ra) was then measured using a surface roughness tester. On the other hand, the top, middle, and bottom area of the kerf surface as well as the dross height were analyzed by scanning electron microscopy (SEM). The highest Ra value was resulted at cutting speed of 2000 mm/min with 2.965 ± 0.05 μm while the lowest was at 1400 mm/min with 2.522 ± 0.16 μm. In parallel, the Ra was found to be higher when subjected gradually from the top to bottom zone. The kerf surface also proved that the top zone is dominated by the cutting zone, while the middle and bottom zone are characterized by the transition and deformation zone respectively. The width between kerf lines increased when the higher cutting speed was performed. Additionally, the larger dross height was found at the cutting speed of 1400 mm/min with 32.75 ± 5.21 μm and then degraded gradually at the higher cutting speed. The heat input and laser capability in exposing the material thickness are responsible for determining the corresponding surface texture aspects.
Analysis of Fire and Smoke Spread in Ki Hajar Dewantara Auditorium, State University of Jakarta, Using Fire Dynamics Simulator Ariq Harits Arrizq; Pratomo Setyadi
Journal of Mechanical Engineering Science and Technology (JMEST) Vol 7, No 1 (2023)
Publisher : Universitas Negeri Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17977/um016v7i12023p076

Abstract

Fire behavior and smoke spread are influenced by various factors, including the amount and condition of combustible material, ventilation openings, and ceiling height. A high amount of combustible material in the auditorium poses a significant fire hazard, hence, efforts need to be made to minimize the risk. One approach is to use Computational Fluid Dynamic software, such as Fire Dynamics Simulator (FDS), to model fire combustion. In this research, it provides an overview of the heat release rate (HRR) of fires that occur as well as the effect of differences in ceiling height and the effect of ventilation on fire spread. This research employed Polyurethane foam, commonly used for auditorium seats, as the sample material. Furthermore, it modeled two fire points, one on the 9th floor and the other on the 10th floor, in the middle of seat rows. The development of fire in the modeling was described by the results of visualization, HRR, burning rate, and temperature rise. These results provided insight into the speed at which fire and smoke spread. The starting point on the 9th floor had the highest flame spread rate due to the ceiling jet phenomenon, where a high amount of combustible material caused the ceiling temperature to increase, producing a heat flux that could burn surrounding seats. In both scenarios, the smoke spread rapidly toward the ventilation openings. However, it was denser on the 9th floor as the starting point was farther from the ventilation openings, and the smoke on the 10th floor was less dense.

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