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PENGARUH KOMPOSISI CU TERHADAP SIFAT MEKANIK DAN STUKTUR MIKRO DARI PENGECORAN AL-SI Anderson, Willy; Rudianto, Haris; Haryadi, Deni
Jurnal Ilmiah Teknologi dan Rekayasa Vol 23, No 2 (2018)
Publisher : Universitas Gunadarma

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35760/tr.2018.v23i2.2464

Aluminium (Al) merupakan logam ringan, mempunyai ketahanan korosi yang baik dan hantaran listrik yang baik dan sifat-sifat baik lainnya sebagai sifat logam, selain itu aluminium juga mempunyai sifat mampu membentuk (machinability). Tembaga (Cu) ditambahkan untuk meningkatkan kekuatan material tersebut, makin tinggi kadar tembaga maka makin banyak fasa yang terbentuk, sehingga kekerasan dan kekuatan paduan akan meningkat. Selain itu, peningkatan komposisi tembaga di dalam paduan Al-Si-Cu dapat juga meningkatkan sifat ketahanan korosi dan sifat ketahanan aus. Penelitian ini bertujuan untuk mengetahui pengaruh komposisi tembaga terhadap sifat mekanik dan struktur mikro dari pengecoran Al-Si. Hasil uji hardness rockwell menunjukkan bahwa semakin banyak unsur Cu yang ditambahkan pada paduan Al-Si maka semakin besar nilai kekerasan dan kekuatan paduan. Hasil pengujian impact charpy didapat nilai impact pada sampel 1 yaitu 0,0307 J/mm2 dan sampel 2 yaitu 0,0129 J/mm2. Hasil pengujian tensile kekuatan tarik sampel 1 yaitu 93.50 N/mm2, sampel 2 yaitu 39.39 N/mm2, dan sampel 3 yaitu 33.60 N/mm2.

MOLECULAR DYNAMICS STUDIES ON THE STRENGTH PREDICTION OF INTERFACE BETWEEN AL-AL4C3 IN METAL MATRIX NANOCOMPOSITES Haryadi, Deni; Rudianto, Haris; Yamin, Mohamad
Jurnal Ilmiah Teknologi dan Rekayasa Vol 25, No 1 (2020)
Publisher : Universitas Gunadarma

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35760/tr.2020.v25i1.2490

In this study, molecular dynamics simulations (MD) will be applied to modelling the Al4C3-aluminum interface in aluminum nanocomposite, Al4C3 is an interface that results from the shaker mill process which becomes a bridge that plays an important role in Carbon particles with Aluminium Matrix and Based on observations from the TEM characterization, it is found that the relationship between Al orientation to Al4C3 is (111) (002) (220). The characteristics of the interface between Aluminum matrix and Al4C3 will be analyzed using uniaxial tension and shear test simulation. The atomic potential used in this simulation is the embedded atomic method (EAM) for Al, empirical-order intermolecular potential (AIREBO) for C and lennard jones for the reaction of Al-C atom. The result shows that, the interface orientation is Al matrix (002) || Al4C3 (003) has the highest interface strength compared to Al matrix (111) || Al4C3 (003) and Al matrix (200) Interface orientation || Al4C3 (003). Results from the molecular dynamics simulations are also discussed with analytical results obtained experimental

Study of First Principles of Mg-Si Binary Systems as Precipitates from T6 Heat Treatment of AL-MG-SI ALLOYS Deni Haryadi; Haris Rudianto
INDONESIAN JOURNAL OF APPLIED PHYSICS Vol 10, No 01 (2020): IJAP Volume 10 ISSUE 01 YEAR 2020
Publisher : Department of Physics, Sebelas Maret University

One of the purposes adding the two main alloying elements Si and Mg in small quantities (≈ 1%) on Aluminum is to form strengthening precipitates in aluminium alloy, which typically contribute with a fivefold strength increase from pure aluminum. In the last decades, the investigation has begun to understand the structure and formation of the different phases during heat treatment. An important precipitate in Al-Mg-Si Alloy is β" and β. when the Precipitate β is created after β" is that the strength suddenly drops and the alloy is said to be overaged. By means of a first-principles supercell approach and density functional theory calculations, this research studied precipitate energy and interface energy of precipitate β" and β. Results show that precipitate β have precipitate energy higher then β" but have interface energy lowers then β". And each low energy interface was found possesses interface with the Al matrix is fully incoherent. The final result of calculation and simulation values for the interfacial energies, precipitate energies and strain energies that can be used in future predictions of the characteristic precipitate.

Optimizing Hot Embossing of Poly(methyl methacrylate) Microfluidic Chip Whulanza, Yudan; Dhira, Pandya; Haryadi, Deni; Soemardi, Tresna P.
Jurnal Teknik Mesin Indonesia Vol. 19 No. 2 (2024): Jurnal Teknik Mesin Indonesia
Publisher : Badan Kerja Sama Teknik Mesin Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36289/jtmi.v19i02.760

Microfluidic research become a more important research field in mechanical and bioengineering fields. The application of microfluidic positively relates to the ability to manufacture micro or precision. Nowadays, the manufacturing in this area is aimed at around 100-500 µm. Here, a hot embossing method is reported to realize microchannel with height and width dimensions of 150-300 µm and 600-800 µm, respectively. This study also shows that the margin factor between the mould/dies to the realized dimension is 50-70% and 5-7% for height and width, respectively.

Design and Implementation of FTTB Network Transmission in High-Rise Buildings Using GPON Yuhani, Ahmad; Haryatmi, Emy; Haryadi, Deni; Arafat, Yunus Bakhtiar
International Journal of Engineering Continuity Vol. 4 No. 1 (2025): ijec
Publisher : Sultan Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58291/ijec.v4i1.375

The advancement of digital communication technology has significantly increased the demand for reliable network infrastructure, particularly in high-rise buildings such as hotels and resorts. This study aims to design and evaluate a Fiber To The Building (FTTB) network system based on Gigabit Passive Optical Network (GPON) technology at The Anvaya Beach Resort Bali. The system is designed to distribute integrated communication services including data voice, and video, through a zoning approach based on the functional layout of the building. The Waterfall method is employed in the system development, encompassing the stages of requirement analysis, topology design, field implementation, and optical performance testing. The findings indicate that most zones have optical attenuation values within the standard range (15–28 dB), and the received signal power remains within the acceptable threshold (-28 dBm). However, several areas exhibit suboptimal signal performance, particularly those with long distribution paths and a high number of optical splitters. Zone C1.1 demonstrates the best performance, with stable attenuation levels and signal strength within standards, without requiring additional active devices. The study concludes that a GPON-based FTTB system can efficiently and flexibly meet the data communication needs of high-rise buildings and other complex building environments with similar systems.

Tax Compliance Dynamics: The Role of Trust, Perception of Power, and Tax Knowledge in Taxpayers Haryadi, Deni; Hidayah, Nurul
Jurnal Ekonomi Teknologi dan Bisnis (JETBIS) Vol. 4 No. 7 (2025): JETBIS : Journal of Economics, Technology and Business
Publisher : Al-Makki Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.57185/jetbis.v4i7.189

This study aims to analyze the influence of trust and power perception on taxpayer compliance in the Jabodetabek area and to examine the moderating role of tax knowledge as a moderating variable. A quantitative approach was employed using a survey method. A total of 350 questionnaires were analyzed using the sampling approach by Hair et al., and the data were processed using Structural Equation Modeling (SEM) with SmartPLS 3.0 software. The results show that trust in tax authorities significantly affects tax compliance, indicating that greater trust leads to higher compliance. Conversely, power perception does not significantly influence compliance, suggesting that perceived authority alone does not directly impact taxpayer behavior. Tax knowledge strengthens the relationship between both trust and power perception with compliance. The study’s practical implication is that tax authorities should emphasize education and trust-based strategies rather than relying solely on authoritative approaches to enhance tax compliance.

Influence of TiO₂ Nanofluid Concentration on Friction Factor and Reynolds Number in Laminar–Turbulent Flow through 4 mm and 6 mm Acrylic Pipes Ali Nashirudin, Hamzah; Samsul Bakhri, Mohammad; Haryadi, Deni; Poernomo Sari, Sri
International Journal of Engineering Continuity Vol. 4 No. 1 (2025): ijec
Publisher : Sultan Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58291/ijec.v4i1.404

This study examines the hydraulic and thermal performance of TiO₂–water nanofluids in small-diameter acrylic pipes, focusing on the influence of nanoparticle concentration and pipe geometry. Experiments were conducted using internal diameters of 4 mm and 6 mm, with TiO₂ volume concentrations of 0.3% and 0.5%. Nanofluids were prepared via a two-step method combining magnetic stirring and ultrasonic sonication to ensure uniform dispersion. Flow parameters, including Reynolds number, friction factor, and Nusselt number, were determined from measured pressure drop and flow rate data. Results show that increasing TiO₂ concentration elevates friction factor, with the effect more pronounced in smaller pipes due to intensified wall shear and higher surface-area-to-volume ratios. The 0.3% nanofluid consistently achieved higher Reynolds numbers and competitive heat transfer performance, while 0.5% concentration often reduced Nusselt number at equivalent flow conditions, likely due to viscosity-induced flow resistance and particle agglomeration. Deviations from classical laminar and turbulent correlations were observed, particularly in the transitional regime, indicating altered boundary layer behaviour. These findings highlight the need for optimised nanoparticle loading and diameter selection to balance heat transfer enhancement against hydraulic penalties in compact thermal management systems.

Tax Compliance Dynamics: The Role of Trust, Perception of Power, and Tax Knowledge in Taxpayers Haryadi, Deni; Hidayah, Nurul
Jurnal Ekonomi Teknologi dan Bisnis (JETBIS) Vol. 4 No. 7 (2025): Jurnal Ekonomi, Teknologi dan Bisnis
Publisher : Al-Makki Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.57185/jetbis.v4i7.189

This study aims to analyze the influence of trust and power perception on taxpayer compliance in the Jabodetabek area and to examine the moderating role of tax knowledge as a moderating variable. A quantitative approach was employed using a survey method. A total of 350 questionnaires were analyzed using the sampling approach by Hair et al., and the data were processed using Structural Equation Modeling (SEM) with SmartPLS 3.0 software. The results show that trust in tax authorities significantly affects tax compliance, indicating that greater trust leads to higher compliance. Conversely, power perception does not significantly influence compliance, suggesting that perceived authority alone does not directly impact taxpayer behavior. Tax knowledge strengthens the relationship between both trust and power perception with compliance. The study’s practical implication is that tax authorities should emphasize education and trust-based strategies rather than relying solely on authoritative approaches to enhance tax compliance.

Molecular Dynamics Studies of The Effects of Copper on The Mechanical Properties of Aluminum Rudianto, Haris; Haryadi, Deni
Journal of Applied Science and Advanced Engineering Vol. 2 No. 1 (2024): JASAE: March 2024
Publisher : Master Program in Mechanical Engineering, Gunadarma University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59097/jasae.v2i1.26

In this research, molecular dynamics (MD) simulations were performed to model the effects of copper content on aluminum properties. Copper has a low solubility in aluminum. Therefore, the main purpose of this research is to study the influence of copper content (Cu) on the mechanical properties of aluminum. Modeling and simulation of nano indentation and uniaxial tension tests were carried out to observe the mechanical properties under the conditions of copper content starting from 0.5 up to 10wt% at 300oK. The interactions between the atoms of aluminum and copper were modeled using Embedded Atom Method (EAM) potentials. The calculation showed that a higher amount of copper increased the tensile strength of aluminum, and in this research,10wt% copper gave the highest tensile strength. But when it comes to the nano indentation test to determine hardness value, it showed that 1wt% copper gave the highest hardness, it assumes that this is related to localization of nano indentation test position optimum formation of intermetallic aluminum-copper, Al2Cu on a certain area.

Analysis of Pressure Drop in Clean Water Piping Installation Using Revit Software Aslamia, Soibatul; Haryadi, Deni; Komarudin, Komarudin
International Journal of Engineering Continuity Vol. 4 No. 2 (2025): ijec
Publisher : Sultan Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58291/ijec.v4i2.405

Clean water piping systems in industrial facilities must be designed to ensure adequate residual pressure at all outlets while minimizing energy losses. One critical factor influencing system performance is pressure drop, which results from both friction in straight pipes and localized losses in fittings, valves, and other components. This study analyzes the pressure drop in the clean water distribution network of PT XYZ, Kendal Industrial Estate, using two approaches: manual calculation based on the Darcy–Weisbach equation with total loss coefficients, and simulation using Autodesk Revit’s Pressure Loss Report tool. The manual calculation yielded a total pressure drop of 2.30 bar (≈ 23.0 mH₂O) along the critical path, with approximately 72% of the loss originating from fittings and 28% from pipe wall friction. The Revit simulation produced a total pressure drop of 2.10 bar (≈ 21.4 mH₂O) for the same route, resulting in a deviation of 8.7%, which is within the accepted tolerance of ±10% for BIM-based hydraulic validation. The results demonstrate that Revit can reliably model hydraulic performance when accurate material, dimension, and fixture data are provided. The findings emphasize that optimization strategies should focus on reducing localized losses by minimizing fittings, improving pipe routing, and increasing branch diameters in high-velocity sections. These measures can enhance residual pressure, improve system efficiency, and reduce pump energy requirements. The study validates the use of Autodesk Revit as an effective tool for preliminary hydraulic analysis in compliance with SNI 03-6481-2000, while confirming the importance of manual validation during the design process.

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