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All Journal Jurnal Teknik Mesin International Journal of Innovation in Mechanical Engineering and Advanced Materials
Haftirman, Haftirman
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Aerospace Engineering Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Energy Engineering Materials Science & Nanotechnology Mechanical Engineering

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HUBUNGAN PENGETAHUAN SISWA TERHADAP IKLIM KESELAMATAN DAN KESEHATAN KERJA DI RPS TEKNIK PENGELASAN SMKN 1 CIBARUSAH wijaya, Surya; Haftirman, Haftirman
Jurnal Teknik Mesin (Journal Of Mechanical Engineering) Vol 11, No 2 (2022)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/jtm.v11i2.15071

Abstract

Penelitian  mengenai hubungan pengetahuan siswa terhadap iklim keselamatan dan Kesehatan kerja (K3) di RPS (Ruang Praktik Siswa) Teknik pengelasan SMKN1 cibarusah adalah untuk mengetahui pengetahuan dan kesadaran siswa terhadap K3 sehingga hasilnya dapat  menghasilkan data yang dapat menghindari/mengurangi kecelakaan kerja dan diharapkan dapat melakukan penekanan tingkat kecelakaan kerja sampai di titik terkecil mendekati  titik nol atau zero accident. Penelitian ini menggunakan metode penelitian kuantitatif deskripsi korelasi. Jumlah siswa untuk penelitian sebagai subjek sebanyak 35 siswa yang terdiri dari kelas X sampai kelas XII dijurusan Teknik Pengelasan SMKN 1 Cibarusah. Teknik pengambilan sampel menggunakan teknik purposive sampling. Instrumen yang diambila adalah pengetahuan keselamatan kerja yang terdiri dari 17 item dengan reliabilitas menggunakan formula Alpha Cronbach sebesar 0,843. Skala iklim keselamatan dan kesehatan kerja yang terdiri dari 16 item dengan reliabilitas menggunakan formula Alpha Cronbach sebesar 0,732.Data hasil penelitian dianalisis menggunakan metode regresi linier berganda. Hasil penelitian dapat disimpulkan bahwa anak kelas X sampai XII rentan terhadap kecelakaan kerja selama melakukan pekerjaan pengelasan yang ini terlihat dari data dimana pemahamansafty procedurebelum diketahui sebahagian besar siswa sehingga pengetahuan tentang keselamatan kerja sejak di bangku SMK tingkat bawah perlu diberikan.
Viability of R-290 Refrigerant as Residential AC Retrofit: Effect of Charge Mass Variations Aulia, Irham; Haftirman, Haftirman; Berman, Ega Taqwali
International Journal of Innovation in Mechanical Engineering and Advanced Materials Vol 7, No 2 (2025)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/ijimeam.v7i2.30904

Abstract

The growing concerns over ozone depletion and global warming caused by refrigerants have led to the search for environmentally friendly alternatives. This study evaluates the impact of varying R-290 refrigerant charge masses on the performance of a wall-mounted residential air conditioner using the drop-in substitute method. A ¾ HP residential AC unit originally charged with 550 grams of R-22 refrigerant was retrofitted with R-290 and tested at charge masses of 140 grams, 165 grams, and 190 grams—approximately 25%, 30%, and 35% of the original R-22 charge, in accordance with the commonly applied “one-third rule.” The results showed that retrofitting with R-290 increased the Refrigeration Effect (RE) by up to 75%, Compression Work (Wc) by 68%, and Coefficient of Performance (COP) by up to 18%. The system with a 25% refrigerant charge was unable to reach the set temperature due to a 23% reduction in cooling capacity, while the 30% charge showed a 10% reduction. The 35% refrigerant mass retrofit proved the most suitable, achieving adequate cooling capacity, an 18% increase in COP, and a 14% reduction in power consumption. Additionally, the retrofit resulted in an indirect CO₂ emission reduction of 1.15 metric tons annually, highlighting the environmental and energy-saving advantages of using R-290. These findings provide empirical validation of the one-third rule for refrigerant mass variation in R-290 retrofits and offer valuable insights into optimizing performance and efficiency in residential AC units, with significant energy and environmental benefits.
STRENGTH ANALYSIS OF STEEL ROPE ON FREIGHT ELEVATOR WITH A HOIST LIFTING CAPACITY OF 3 TONS Risdiyan, Asep; Haftirman, Haftirman; Arwati, I Gusti Ayu
Jurnal Teknik Mesin (Journal Of Mechanical Engineering) Vol 13, No 2 (2024)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/jtm.v13i2.19053

Abstract

Steel rope has advantages over chains, but also has disadvantages. The advantage is that it is resistant to shock loads, if it breaks it shows a brittle sign on one of the wires (Houda Mouradi, 2018). The drawbacks are that they are not resistant to corrosion, are difficult to bend, can stretch or elongate, and tend to rotate (Aginaparru, 2018). In this study the analysis carried out was the process for the Salt Spray test to determine the effect of the corrosion rate on steel rope and the tensile test process aimed at determining the phase transformation, plasticity, creep, fatigue, to the fatigue point, as well as metallographic tests for changes in the properties mechanic. Loss or loss of weight on steel rope type 6 x Fi (29), diameter 13 from the salt spray test process, increased the corrosion rate from 0.21 mpy to 0.23 mpy. The greater the tensile force, the greater the tensile stress that occurs. And the greater the tensile force, the greater the elastic modulus that occurs from the elastic limit to the fatigue limit due to the magnitude of the tensile force that exceeds the limit. In metallographic testing using the ASTM 317 / ASTM E 407 method, it can be concluded that the steel rope has a modulus of elasticity, visible crack lines in the steel rope structure indicating that the steel rope has undergone an elastic process to the fatigue limit or fracture limit. Keywords: Salt Spray, wire, creep, fatigue 
Co-Authors A-Samarai, Riyadh A. Aulia, Irham Ega Taqwali Berman I Gusti Ayu Arwati Risdiyan, Asep Surya Wijaya