cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Rahmat Azis Nabawi
Contact Email
raazna@ft.unp.ac.id
Phone
+6281277328670
Journal Mail Official
Syahril@ft.unp.ac.id
Editorial Address
Jl. Prof. Dr. Hamka Kampus UNP Air Tawar
Location
Kota padang,
Sumatera barat
INDONESIA
Teknomekanik
Published by Universitas Negeri Padang
ISSN : 26219980     EISSN : 26218720     DOI : 10.24036/tm.
Core Subject : Engineering,
Mechanical Engineering
Teknomekanik is an international journal that publishes peer-reviewed research in engineering fields (miscellaneous) to the world community. Paper written collaboratively by researchers from various countries is encouraged. It aims to promote academic exchange and increase collaboration among scientists, engineers and researchers to support sustainable development goals.
Arjuna Subject : Teknik (semua kategori) - Teknik Mesin
Articles 99 Documents
 6   7   8   9   10 
The impact of exponentially varying viscosity on magnetized tangent hyperbolic nanofluid over a nonlinear stretching sheet with PHF and PMF conditions Ghazy, Mohamed Magdy; Mekheimer, Khalid Saad; Abo-Elkhair, Rabea Elshennawy; Megahed, Ahmed Mostafa
Teknomekanik Vol. 8 No. 1 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i1.33772

Abstract

This article aims to explore the characteristics of tangent hyperbolic nanofluid flow over a nonlinear exponentially stretching sheet with suction or injection embedded in a Darcy porous medium. We consider a non-Newtonian magnetohydrodynamic fluid with prescribed surface temperature and temperature-dependent viscosity, relevant to applications in aerospace, automotive and marine engineering, electronic cooling, solar-energy systems, and filtration. Given its fundamental importance, the study of prescribed exponential order heat flux (PHF) and prescribed mass flux (PMF) of hyperbolic tangent nanofluid became a key in research aimed at improving the efficiency and performance of these systems. The partial differential equations are converted into ODES by using transformation procedure. The system of transformed equations is numerically solved by Chebyshev spectral method. Graphical results illustrate the impact of key parameters on concentration, velocity, and temperature profiles, while tabulated data report the local Nusselt number, Sherwood number, and skin friction coefficient. Our results show that increasing both the power-law index and the variable-viscosity parameter reduces the fluid’s velocity while elevating its temperature and concentration. The comparative analysis confirms a high degree of agreement with previous studies. This research holds significant importance as it focuses on the extensive utilization of tangent hyperbolic nanofluids in cooling electronic components that produce substantial heat during their operation.
Durability performances of ferronickel slag aggregate and seawater concrete Sandra, Nevy; Caronge, Muhammad Akbar; Sunaryati, Jati; Kawaai, Keiyu; Nsama, Willick; Arbi, Yaumal; Arifin, Ari Syaiful Rahman
Teknomekanik Vol. 8 No. 1 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i1.34572

Abstract

The rising demand for concrete in the building sector has resulted in the exhaustion of natural sand and freshwater supplies, leading to the pursuit of sustainable substitutes. Coastal areas have plentiful ferronickel slag (SL) and seawater (SW), which can be used to manufacture concrete. Nevertheless, the possibility of corrosion to steel reinforcement raises concerns that require further research. This investigation examines the mechanical and durability performance of concrete that incorporates SL as a partial replacement for fine aggregate and SW as a mixing component. The objective is to optimize SL content to improve compressive strength, resistance to chloride ions, and overall durability. Experimental results show that replacing 25% of the aggregate with SL yields the best combination of workability, strength, and durability, significantly enhancing compressive strength, decreasing porosity, and lessening chloride ion penetration, as evidenced by the Rapid Chloride Penetration Test (RCPT). Although seawater promotes early-age hydration and strength development, its extended use slightly diminishes compressive strength due to salt-induced micro-cracking. However, SL counters these effects, making SW–SL mixture a feasible and sustainable option for concrete production in coastal and resource-limited areas. A significant relationship between RCPT and compressive strength underscores the important role of SL in densifying the matrix and improving impermeability. The concrete mixture with 25% SL exhibits the lowest abrasion weight loss at 28 and 120 days, showing improved durability. This study highlights the potential of using SL and seawater to create eco-friendly and high-performance concrete for harsh environments.
Microstructural and mechanical properties of 17-4PH stainless steel fabricated via material extrusion 3D printing Cao, Dang Long; Nguyen, Van Cuong; Thi, Van Nga Tran
Teknomekanik Vol. 8 No. 1 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i1.34872

Abstract

This study investigates the microstructural and mechanical properties of metal 3D printing products fabricated using material extrusion technology. It focuses on the critical post-processing stages: printing, washing, and sintering. A Markforged 3D printing system and 17-4 PH stainless steel material were utilized to assess the effect of printing orientation and sintering conditions on microstructural and mechanical properties of the final product. The results demonstrate that printing orientation and sintering conditions critically govern the microstructural and mechanical properties of the final product. During sintering, the microstructure undergoes significant phase transformation and densification, while micropores and shrinkage voids emerge due to capillary stresses during binder removal. Furthermore, the mechanical properties are significantly influenced by the combined effects of printing orientation and sintering conditions. Optimizing deposition parameters (printing orientations and sintering conditions) substantially enhances the mechanical performance of the final printed product.
Characteristics of sisal-epoxy composite boards with sodium chloride-treated fibers at different treatment temperatures Setyayunita, Tamaryska; Suryanto, Heru; Aminnudin, Aminnudin; Osman, Azlin Fazlina; Yanuhar, Uun
Teknomekanik Vol. 8 No. 1 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i1.35572

Abstract

The growing environmental concerns associated with synthetic fibers have led to the increased adoption of bio-fibers as reinforcements in polymer composites. Sodium chloride (NaCl) is explored as a fiber treatment agent to enhance the adhesion between fibers and the matrix. The study aims to evaluate the effects of NaCl treatment on the characteristics of sisal fiber-epoxy composite boards. A completely randomized design was applied with three factors: treatment temperature (25 °C and 100 °C), NaCl concentration (1, 3, and 5 wt%), and composite board density (0.40, 0.60, and 0.80 g/cm³). Sisal fibers were soaked in NaCl solutions for one hour, rinsed, dried, and manually blended with epoxy at a ratio of 80:20 wt%. Composite board properties were observed according to the standards of JIS-A-5908, Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). Results indicated that increasing the NaCl concentration and treatment temperature significantly improved the properties of the composite board. The optimal parameters (5wt% NaCl, 100 °C, 0.80g/cm³) yielded a modulus of elasticity of 4.59±0.26 GPa, modulus of rupture of 18.88±0.03 MPa, and internal bond strength of 3.92±0.18 MPa, representing increases of 200.32%, 130.65%, and 218.70%, respectively. Thickness swelling decreased to 2.13±0.43% (48.14%) and water absorption to 8.95±0.05% (32.25%). These findings confirm that NaCl treatment is an eco-friendly method to enhance the mechanical strength and moisture resistance of biofiber composites. It also supports the development of high-performance composite boards.
High-pressure adsorption isothermal on a novel microporous material from polyethylene terephthalate plastic waste in carbon dioxide capture applications Martin, Awaludin; Taer, Erman; Nasruddin, Nasruddin; Khotimah, Nur
Teknomekanik Vol. 8 No. 1 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i1.36172

Abstract

Carbon capture is a vital strategy for mitigating climate change by reducing industrial CO2 emissions. Adsorption technology using microporous material shows significant promise. However, significant challenges persist in developing cost-effective and sustainable adsorbents. This study addresses this issue by simultaneously enabling CO2 adsorption and plastic waste utilization through activated carbon derived from polyethylene terephthalate (PET). It was evaluated under isothermal conditions (27°C, 35°C, and 45°C) at pressures up to 3500 kPa. The maximum CO2 adsorption capacity was 0.21313 kg/kg at 27°C and 3504.39 kPa, demonstrating the effectiveness of PET-derived activated carbon in capturing CO2. The Toth isotherm model exhibited a strong fit with experimental data, with an R2 of more than 99%. The Clausius-Clapeyron equation yielded an adsorption heat of 2223.66 kJ/kg using the Toth fitting, and the Chakraborty-Saha-Koyama model yielded a heat of 2383.65 kJ/kg, confirming strong adsorption potential. These results underline PET waste as a viable precursor for sustainable carbon capture adsorbents. Furthermore, the results provide essential data for developing numerical models to optimize adsorption-based carbon capture technologies.
Design, simulation, and static testing of an eco-friendly prosthetic foot using ramie-PLA composite Sopiyan, Iyan; Soemardi, Tresna P.; Purnomo, Herry; Polit, Olivier
Teknomekanik Vol. 8 No. 1 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i1.36572

Abstract

This study developed a sustainable lower-limb prosthetic prototype using biodegradable ramie fiber-reinforced PLA composite as its primary material. The design specifically addresses the needs of individuals with limb amputation while prioritizing environmental sustainability. PLA-based composites for structural biomedical applications—particularly those in lower-limb prosthetics—must meet rigorous mechanical and fatigue performance requirements under repetitive loading. This study investigates the development of a transtibial prosthetic foot prototype using a quasi-isotropic lay-up prepreg ramie-PLA composite fabricated via the hot press method. Material characterization was conducted per ASTM standards, and the design was evaluated using the Finite Element Method (FEM). The prototype underwent static testing according to ISO 22675 with a user load criterion. The laminate exhibited an ultimate tensile strength of 48.36 ± 0.95 MPa, an elastic modulus of 4.125 ± 0.25 GPa, and a flexural strength of 62.06 ± 3.43 MPa. FEM results showed that all normal and shear stresses during heel strike (17.78 MPa and 1.71 MPa) and toe-off (12.38 MPa and 5.69 MPa) phases remained below fatigue limits. Experimental static stresses were heel strike (12.72 MPa) and toe-off (20.09 MPa), both within safe operational limits. These findings highlight the structural viability and environmental sustainability of ramie-PLA composites, positioning them as a promising material for next-generation prosthetic foot development.
SIWEC-R: A rank-sensitive improvement to SIWEC methodology Trung, Do Duc; Özçalıcı, Mehmet; Ersoy, Nazlı; Duc, Duong Van; Bao, Nguyen Chi; Son, Nguyen Hoai
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.40172

Abstract

Determining the weights of criteria is a critical step in ranking alternatives characterized by multiple, often conflicting criteria which is a core challenge in Multi-Criteria Decision Making (MCDM). This study introduces the SIWEC-R method, a novel two-stage approach that integrates the SIWEC and R methodology to achieve more accurate and reliable weighting of criteria. Alongside the SIWEC-R method, a new performance metric, the UTAC score, was introduced to capture ranking consistency and strength across various MCDM methods. To ensure a comprehensive evaluation, sensitivity analysis was extended to cover all possible subsets of alternatives, offering an unprecedented level of scrutiny. Comparative assessments across three diverse case studies demonstrated that SIWEC-R consistently outperforms the original SIWEC method, achieving higher Spearman rank correlation coefficients and demonstrating superior robustness under sensitivity analysis. These compelling results firmly establish SIWEC-R as a significant advancement in the field of criteria weighting, delivering enhanced decision-making reliability for complex and uncertain environments.
Investigation of corrosion, hardness, and wear rate of rice husk-zinc composite coating on A36 steel using dual anode electrolytic deposition technique Ajayi, Samuel; Ikubanni, Peter; Onu, Peter; Adekanye, Timothy A.; Oyewo, Abideen T.; Ajide, Olufemi
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.42172

Abstract

Zinc-bas ed composite coatings developed from synthetic ceramics (Si3N4, SiC, and Al2O3) have recently been employed as reinforcement to enhance their resistance to deterioration. However, there is limited literature on the utilization of ceramic particles sourced from agro-industrial wastes in the formulation of these coatings. This study investigated the effect of the surface improvement process (SIP) using rice husk (RH) nanoparticles on the hardness and wear rate of A36 steel. The A36 steel, zinc bar, and RH nanoparticles were procured and characterized using Energy Dispersive Spectroscopy (EDS). Four cathode specimens were produced, including an as-received specimen of A36 steel and two anodes of zinc. Four steel specimens coated with Zn-10RH(t25), Zn-10RH(t30), Zn-15RH(t25), and Zn-15RH(t30), denoted as S1, S2, S3, and S4, respectively, were developed with concentrations of 10 or 15 g/L and deposition times of 25 or 30 minutes at a constant cell voltage of 0.5 V. The as-received substrate steel was used as the control specimen (CS). The hardness and wear rate (WR) properties of the deposited samples were examined using Vickers hardness (HV) and a Pin-on-disc tribometer, respectively. All coated specimens exhibited substantial improvements in hardness and wear rate properties compared to CS (Hardness = 85.82±0.45 HV and WR = 2.45±0.34 g/min). For the coated specimens, the hardness and WR values ranged from 188.50 to 288.37 HV, 260.34 to 284.38 MPa, and 0.01 to 0.02 g/min, respectively. The inclusion of the coatings significantly enhanced the mechanical properties of the deposited specimens.
Performance analysis of soybean oil with CuO/Graphene hybrid additive nanoparticles as cutting fluid on CNC machining processes Agus Setiawan; Puspitasari, Poppy; Tauviqirrahman, Mohammad; Pramono, Diki Dwi; Salam, Haipan
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.42472

Abstract

This study investigates the performance of soybean oil-based nano-lubricants with CuO, graphene, and CuO/graphene hybrids under MQL-assisted CNC milling of AISI 1045 steel. The research aims to evaluate the thermophysical, rheological, and tribological properties of various lubricant formulations, including pure soybean oil and soybean oil with individual or hybrid nanoparticle additives. Nanoparticles were characterized by SEM, XRD, and FTIR, and fluid samples were evaluated for density, viscosity, thermal conductivity, sedimentation stability, and rheological behavior. Machining performance was assessed through tool wear, surface roughness, cutting temperature, wear debris morphology, and chip color analysis. Results showed that adding graphene nanoparticles significantly improved machining performance, achieving a surface roughness of 1.033 µm, tool wear of 0.0493 mm, and a cutting temperature of 46.1 °C, outperforming both conventional and alternative nanofluid formulations. Among all formulations, the graphene-based nanofluid delivered the lowest cutting temperature, surface roughness, and flank wear under MQL. The CuO/graphene hybrid improved performance relative to the base fluids but did not surpass the graphene formulation, indicating limited synergistic benefits under the present soybean oil-based-MQL conditions.

Page 10 of 10 | Total Record : 99

 6   7   8   9   10 

Filter by Year

2018 2025


Reset
Filter By Issues
All Issue Vol. 8 No. 2 (2025): Regular Issue Vol. 8 No. 1 (2025): Regular Issue Vol. 7 No. 2 (2024): Regular Issue Vol. 7 No. 1 (2024): Regular Issue Vol. 6 No. 2 (2023): Regular Issue Vol. 6 No. 1 (2023): Regular Issue Vol. 5 No. 2 (2022): Regular Issue Vol. 5 No. 1 (2022): Regular Issue Vol. 4 No. 2 (2021): Regular Issue Vol. 4 No. 1 (2021): Regular Issue Vol. 3 No. 2 (2020): Regular Issue Vol. 3 No. 1 (2020): Regular Issue Vol. 2 No. 2 (2019): Regular Issue Vol. 2 No. 1 (2019): Regular Issue Vol. 1 No. 2 (2018): Regular Issue Vol. 1 No. 1 (2018): Regular Issue More Issue