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All Journal Jurnal Mekanova : Mekanikal, Inovasi dan Teknologi Vocatech : Vocational Education and Technology Journal Jurnal VORTEKS Jurnal Derma Pengabdian Dosen Perguruan Tinggi (Jurnal DEPUTI) Journal of Innovation Research and Knowledge Jurnal Pengabdian Mandiri Jurnal Teknik Mesin Sinergi
Refiza, Refiza
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The Effect of fuel mixture composition on gasoline engine emissions in urban conditions Siregar, Zufri Hasrudy; Nasution, Arif Fadillah; Fazri, Muhammad; Refiza, Refiza; Puspita, Riana; Thamrin, Husni; Nasution, Asmara Sari
Jurnal VORTEKS Vol. 5 No. 2 (2024): October 2024
Publisher : Program Studi Teknik mesin, Fakultas Teknik, Universitas Al Azhar Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.54123/vorteks.v5i2.389

Abstract

The increasing number of motorized vehicles in urban areas significantly impacts air quality and public health. Gasoline engine emissions, including CO, HC, and NOx, contribute to pollution issues such as volatile organic compounds (VOCs) and secondary organic aerosols (SOAs). Understanding these factors is crucial for developing effective emission control strategies. This study investigates the effect of ethanol-blended gasoline on vehicular emissions, focusing on CO, HC, and NOx. The research aims to optimize fuel mixtures to reduce harmful emissions while considering environmental and health impacts. The study uses a quantitative experimental design, combining laboratory tests with field trials on 10 vehicles under controlled conditions. Results show that ethanol-blended fuels significantly reduced CO emissions, from 2.4 g/km (E0) to 1.5 g/km (E30). A moderate reduction was observed in HC emissions, from 0.55 g/km (E0) to 0.40 g/km (E30). A slight decrease in NOx emissions was noted. Ethanol's oxygen content improves combustion efficiency, reducing CO and HC emissions, but may slightly increase NOx due to combustion temperature changes. This study highlights the potential of ethanol as an environmentally friendly fuel alternative, with further research needed to address NOx-related challenges
Rancang mesin peraut lidi kelapa sawit dengan menggunakan motor listrik kapasitas 1800 lidi/jam Siregar, Zufri Hasrudy; Ramadhan, Andri; Syafputra, Nanda; Mawardi, Mawardi; Refiza, Refiza
Jurnal Mekanova : Mekanikal, Inovasi dan Teknologi Vol 10, No 2 (2024): Oktober
Publisher : universitas teuku umar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35308/jmkn.v10i2.10595

Abstract

The palm oil industry is a vital sector in Indonesia, yet it still faces challenges in optimizing waste management, particularly with palm leaf midribs, which are commonly used in various industries. This research aims to design an efficient and economical palm leaf midrib shaving machine with a capacity of 1800 midribs per hour. The novelty of this research lies in the development of a specialized machine for palm leaf midribs, a topic that has not been extensively studied. The research methodology employed is engineering design, involving needs analysis, conceptual design, and implementation using a 0.5 HP electric motor. The materials and tools used include mild steel, stainless steel 304, wood, and other manufacturing components designed for durability and efficiency. The results show that the machine is effective in shaving midribs with a shaft force of 1.91 N and a power output of 0.425 kW, meeting the specified design requirements. In conclusion, this machine can enhance the efficiency of midrib production processes and contribute to more sustainable waste management in the palm oil industry..
PROSES PEMANENAN HASIL TANAMAN UNTUK KECUKUPAN PANGAN MAHASANTRI PENGHAPAL AL QURAN DI YAYASAN LAYAR DAKWAH Masdania Zurairah; Muhammad Fiza Lubis; Muhammad Fazri Pasaribu; Refiza, Refiza; Refiza4, Edi Syahputra Saragih
JURNAL PENGABDIAN MANDIRI Vol. 4 No. 7: Juli 2025
Publisher : Bajang Institute

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Abstract

The harvesting process for each plant is different according to the time. The harvesting process to achieve maximum results is carried out by maintenance, fertilization and watering. The harvesting process for chilies, tomatoes, eggplants, pumpkins, long beans, peanuts and cassava. Harvesting is done by pulling out such as peanuts, by pulling out plants with loose soil, the pulling process is very easy to do, so that it will produce peanuts in the soil. Likewise, cassava harvesting is done by pulling out or pulling the tree trunk until the cassava fruit is also pulled. Chilies, tomatoes, eggplants, long beans and pumpkins are harvested by picking them. The fastest harvest time is tomatoes 60 days. The longest time to harvest is cassava up to 240 days. With this post-harvest, it can meet the needs of students in food
ANALISA PRODUKTIVITAS PRODUKSI OLEIC ACID MENGGUNAKAN METODE OBJECTIVE MATRIX (OMAX) DI PT. PERMATA HIJAU GROUP Iqbal Habibi; Refiza, Refiza; Rizkha Rida; Sanco Simanullang
Journal of Innovation Research and Knowledge Vol. 5 No. 3: Agustus 2025
Publisher : Bajang Institute

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Abstract

PT. Permata Hijau Group is a company that continues to develop both upstream and downstream, especially at the product sales level. Oleic acid is one of the expensive products sold among oleochemical processing companies. In producing oleic acid, several large costs were found due to lengthy repairs and the plantation not operating. So methods are needed to increase productivity. Analysis using the objective matrix (OMAX) method is a method that is widely used in analyzing the productivity of a company. The method used is the use of OMAX, including determining criteria, determining performance, determining average productivity values, determining the highest and lowest productivity values, determining realistic productivity values, determining scores and value weights, determining productivity indices and making cause-cause diagrams. consequence (fishbone). The results obtained from applying the objective matrix (OMAX) method include the first being the highest productivity index value in October 2023 of 66.66% and the lowest in September of -64.93%. The second result is that the factors that have the most influence on oleic acid productivity. And the third result is that 6 proposed actions are needed to increase oleic acid productivity
PENGUKURAN HUMAN KAPITAL KARYAWAN DENGAN MENGGUNAKAN METODE RETURN ON INVESTMENT DI PT. XYZ TANJUNG MORAWA MEDAN Jonperson Tamba; Refiza, Refiza; Rizkha Rida
Journal of Innovation Research and Knowledge Vol. 5 No. 5 (2025): Oktober 2025
Publisher : Bajang Institute

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Abstract

PT. XYZ merupakan suatu perusahaan yang bergerak di bidang pengolahan minuman, penelitian ini dilatar belakangi karena belum adanya sistem penilaian dalam kinerja karyawan yang bertujuan untuk menghitung tingkat pengembalian investasi oleh karyawan. Tingginya biaya sumber daya manusia pada PT. XYZ merupakan faktor untuk merancang sistem dalam pengukuran tingkat pengembalian investasi dengan return on invesment. Oleh karena itu perlunya dirancang sistem untuk melihat tingkat pengembalian investasi oleh karyawan tersebut terhadap perusahaan PT. XYZ, adapun langkah-langkah untuk melakukan pengukuran return on investment adalah melakukan pengukuran revenue per employee, pengukuran human capital cost factor, pengukuran human capital value added, pengukuran human capital return on investment menggunakan data biaya yang telah dikeluarkan perusahaan kepada karyawan, biaya-biaya tersebut adalah biaya remunerasi, biaya turn over dan biaya temporer. Hasil dari pengukuran return on invesment pada PT. XYZ menunjukkan pengembalian investasi yang mungkin diperoleh pada tahun 2017 sebesar 367,08 %, tahun 2018 sebesar 363,63 % dan tahun 2019 sebesar 337,6 %. Dari hasil pengukuran terhadap sumber daya manusia diperoleh bahwa sistem pengukuran return on investment menunjukkan pengembalian investasi oleh sumber daya manusia terhadap PT. XYZ sangat tinggi dilihat pada tahun 2017, 2018 dan 2019
Evaluasi Kritis dan Model Alternatif Hunter Curves untuk Sistem Plumbing Gedung Bertingkat di Medan Siregar, Zufri Hasrudy; Nasution, Arif Fadillah; Mawardi, Mawardi; Refiza, Refiza; Suherman, Suherman
Jurnal Mekanova : Mekanikal, Inovasi dan Teknologi Vol 11, No 2 (2025): Oktober
Publisher : universitas teuku umar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35308/jmkn.v11i2.13638

Abstract

Clean water is a fundamental necessity in high-rise buildings, so calculating peak water demand is a critical aspect of plumbing system design. So far, planners in Indonesia still rely on Hunter Curves (1940), a classic method developed in the United States and has been used for more than eight decades. The Hunter method is no longer relevant because water consumption patterns have changed, the use of water-saving devices is becoming more widespread, and the characteristics of tropical buildings in Indonesia are different from Hunter's basic assumptions. This study critically evaluates Hunter Curves through a case study of the Lexington Tower Medan Healthcare Building (20 floors, 160 units), comparing the Hunter method with an alternative model based on a locally calibrated Monte Carlo probabilistic simulation (P95). Monte Carlo simulations were performed in 10,000 iterations using MATLAB-based stochastic modeling to obtain peak discharge distributions. The results showed a peak discharge according to Hunter of 34,695 L/s, while the alternative model reached 37,440 L/s (+7.91%). This difference affects the pipe dimensions and pump power, but the additional energy cost (±Rp850,000/year) is commensurate with the increased reliability of the system. This study confirms that Hunter Curves are obsolete and need to be replaced by a more accurate, energy-efficient, and sustainable approach
Co-Authors Ali Imran Asmara Sari Nasution Damanik, Rahmat Indrajaya Fazri, Muhammad Husaini, Muhammad Alwi Husni Thamrin Ikhwan, Rosendra Iqbal Habibi Jayawarsa, A.A. Ketut Jonperson Tamba Masdania Zurairah Maulana, Acim Muhammad Fazri Pasaribu Muhammad Fiza Lubis Muhammad Irwansyah, Muhammad Nasution, Arif Fadillah Raden Mohamad Herdian Bhakti Ramadhan, Andri Rambe, Fajar Noer Refiza4, Edi Syahputra Saragih Rezeki, Rahmad Riana Puspita, Riana Rida, Rizkha Rigitta, Prinsi Rizkha Rida Safitri, Indriani Saktisahdan, T. Jukdin Sanco Simanullang Saragih, Edy Syahputra Silaban, Donni Simanullang, Irwan Prasetya Simorangkir, Simon Petrus Siregar, Masdania Zurairah Siregar, Roswani Siregar, Zufri Hasrudy Soaloon, Humala Raja Suherman, Suherman Syafira, Nadira Syafputra, Nanda Syuhada, Ferry Trisilo, Muji Zurairah, Masdania