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All Journal Semesta Teknika BERDIKARI : Jurnal Inovasi dan Penerapan Ipteks Teknika STTKD: : Jurnal Teknik, Elektronik, Engine Jurnal Polimesin
Muhammad Nadjib
Universitas Muhammadiyah Yogyakarta
Automotive Engineering Computer Science & IT Control & Systems Engineering Education Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

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Pengaruh Komposisi Biodisel Jagung Terhadap Sifat-Sifat Campuran Biodisel Jatropha-Jagung Wahyudi Wahyudi; Andre Sasuta; Muhammad Nadjib
Semesta Teknika Vol 22, No 2 (2019): NOVEMBER 2019
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.222249

Abstract

Biodisel merupakan bahan bakar alternatif untuk mesin disel yang biasanya terbuat dari minyak nabati. Minyak jatropha dan minyak jagung merupakan bahan baku biodisel yang potensial. Namun biodisel dari bahan baku minyak jatropha memiliki kelemahan, diantaranya adalah viskositas yang relatif tinggi dan nilai kalor yang relatif rendah. Salah satu upaya perbaikannya adalah pencampuran dengan minyak jagung. Penelitian ini bertujuan untuk mengetahui pengaruh dari variasi komposisi campuran terhadap karakteristik biodisel. Kedua jenis bahan baku diproses menjadi biodisel melalui reaksi transesterifikasi. Selanjutnya dilakukan pencampuran antara biodisel jatropha dan biodiesel jagung. Campuran dibuat dalam sembilan variasi komposisi. Setiap komposisi campuran diaduk dan dipanaskan pada suhu 90 °C selama 60 menit. Hasil penelitian menunjukkan bahwa campuran biodisel jatropha dan jagung memiliki viskositas yang lebih rendah daripada biodisel jatropha murni. Densitas dan titik nyala campuran biodisel tersebut juga mengalami penurunan. Hasil lainnya adalah nilai kalor biodiesel campuran lebih tinggi daripada nilai kalor biodiesel jatropha murni. Biodiesel is an alternative fuel for diesel engines that are usually made from vegetable oil. Jatropha and corn oil are potential biodiesel feedstocks. However, biodiesel from jatropha oil has disadvantages, including high viscosity and relatively low heating value. An effort to improve its properties is mixing it with corn oil. The purpose of this study was to determine the effect of the composition of the mixture on the biodiesel properties. Both raw materials were processed into biodiesel through transesterification reactions. The next step is mixing jatropha and corn biodiesel. There were nine variations of the biodiesel mixture. Each mixture was stirred and heated at 90 °C for 60 minutes. The results showed that the mixture of jatropha and corn biodiesel had lower viscosity than pure jatropha biodiesel. Density and flash point of the biodiesel mixture also decreased. The heating value of mixed biodiesel is higher than its of pure jatropha biodiesel.
Efek Variasi Beban Pendinginan Terhadap Coefficient Of Performance (Cop) Alat Uji Pengukuran Koefisien Evaporasi Menggunakan Refrigeran R-134A Tito Hadji Agung Santosa; Muhammad Nadjib; Thoharuddin Thoharuddin; Muhammad Akhid Riza
Semesta Teknika Vol 20, No 2 (2017): NOVEMBER 2017
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v20i2.3412

Abstract

Investigation of the cooling load effect toward Coefficient of Performance (COP) is important to conduct. The Coefficient of Performance (COP) is related with compressor work and refrigeration capacity in order to produce a refrigeration system which have a high COP. The high COP value can be reached with minimum compressor work, however it has a maximum refrigeration capacity. This research is to know the effect of cooling load variation toward the performance of experimental device of evaporation heat transfer measurement. By knowing the changing of performance toward cooling load variation, it can be useful in design of an effective and efficient air conditioning system.The method of coolecting data is by experimental method that is by varying water mass flowrate (cooling load) which is flowed to evaporator. An evaporator is soak in a 30 xm x 15 cm x 20 cm water box. Water flowrate can be varied and be masured by a water rotameter. Refrigerant is using Freon R-134a. Experiment is conducted with an evaporation heat transfer coefficient device. The device is a model of modified refrigeration system by adding instruments : an orifice, a test section, and an electric heater. Thermocouple and some pressure gauges is installed at some points which has been determined. Thermocouple and pressure gauges is used to collect temperature and pressure data. After conducting an experiment by evaporator cooling load variation, temperature and pressure data is got. Furthermore based on the temperature and pressure data, the enthalpy is got and can be used to counting the compressor power. Refrigeration capacity can be counted from total heat absorbed by evaporator from water and is divided refrigerant mass flowrate. In this research is got results that cooling load given in evaporator enfluences the COP of the experiment device. By increasing in cooling load at the determined variation, the Coefficient of Performance (COP) of the device is increase. In this research it get results increasing of COP at some refrigerant mass flowrate. The maximum result is get at minimum range inverter variation, that is 16 Hz (ṁr = 9,4 g/s - 10,26 g/s) and the maximum cooling load variation is 2 LPM with COP of 4,96. Whereas the minimum results is get at the maximum inverter range variation, that is 24 Hz (ṁr = 11,83 g/s - 12,25 g/s) and the minimum cooling load variation is 1 LPM with COP of 1,98. This research give some information, if a cooling load of an air conditioning room is chanhing, then it will change the parameter (temperature and pressure) and COP of the air conditioning system in a room.
Pemantauan Lapangan Sistem Penerangan Tenaga Surya 6 x 50 Wp di Sleman Muhammad Nadjib
Semesta Teknika Vol 14, No 2 (2011): NOVEMBER 2011
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v14i2.540

Abstract

Solar module and battery are important components in photovoltaic systems. These components have higher investment cost compared to controller device, lamp, cable, and the frame. Currently, there are six of 50 Wp of solar lighting systems (SLS) installed for cowshed lighting purpose in Sleman. The aim of this research is to investigate the pattern of electricity usage in SLS and to assess its performance, especially in the solar modules and their batteries after two months period of operation. The output voltage and current of solar module, the voltage of charging battery, the load consumption time, and the battery voltage at the end of charging and discharging were measured. The data were analyzed to determine the output power of solar module, average daily load, system performance ratio, and battery performance. It was revealed that the average daily load and performance ratio are 7.26 Ah/day and 49% respectively. Whilst at the end of charging of the battery is 100%, the maximum depth of discharge is 18.03% and its average efficiency is 59.85%. Overall, the SLSs have been well-operated; the solar module has produced electricity and all of the batteries were fully charged from the daily sunlight. However, it appears that the level of electric energy usage is still low. To increase the SLS’s efficiency it is recommended to optimize the usage of the produced electricity by intensifying livestock handling during night time. This solution also needs periodical monitoring of the SLSs which in turn will increase their lifetime.
Perpindahan Kalor pada Penukar Kalor Selongsong dan Pipa Memakai Sekat Miring Tidak Sejajar Muhammad Nadjib
Semesta Teknika Vol 15, No 1 (2012): MEI 2012
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v15i1.441

Abstract

Generally speaking, baffle installation of a shell-and-tube heat exchanger is in straight-standing with respect to shell axis. A common problem of this arrangement is that there will be found a stagnant fluid condition in the death-zone. The impact is the heat transfer coefficient could not reach an optimum value. Based on baffle configuration, the death-zone effect can be minimized by installing an un-parallel tilted baffle. The purpose of this research is to investigate the effect of using non-parallel tilted baffle on heat transfer coefficient. The heat exchanger model was made with single pass fluids. Hot water is going through inside the tube bundles and cold water pass is in the shell. The baffle was installed in various angle of 0°, 15°, 30°, and 45° with respect to shell axis. The cold water flow rates were varied from 75 l/hr, 100 l/hr, 125 l/hr, 150 l/hr, 175 l/hr, to 200 l/hr. The hot water flow rate was fixed at 150 l/hr. Temperature of the hot and cold water at inlet and outlet was recorded by means of K type thermocouple and data logger. The data was then analyzed to obtain the convection heat transfer coefficient. The data were also used to determine the empirical correlation of Nusselt number and Reynolds number. The results indicate that baffle in angle 0° produce the highest convection heat transfer coefficient. Installing the baffle at tilted position is not significant in convection heat transfer coefficient. The empirical correlation of Nusselt number and Reynolds number is influenced by angle function of the baffle.
Studi Termoelectric Generator untuk Solusi Pemanfaatan Waste Energy dengan Peltier Sebagai Sistem Pengkondisi Temperatur Gaguk Marausna; Joni Kasmara; Muhammad Nadjib
Teknika STTKD: : Jurnal Teknik, Elektronik, Engine Vol 6 No 1 (2020): Teknika STTKD: Jurnal Teknik, Elektronik
Publisher : Sekolah Tinggi Teknologi Kedirgantaraan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (627.015 KB) | DOI: 10.56521/teknika.v6i1.186

Abstract

Waste heat dapat dimanfaatkan untuk menghasilkan energi listrik, terutama waste heat dari flue gas mesin pesawat yang tersedia untuk membangkitkan energi listrik menggunakan thermoelectric generator (TEG). Penambahan phase change materials bertujuan meningkatkan kesetabilan sistem dan menyimpan energi dalam bentuk kalor laten dan sensibel. Untuk mendapatkan temperatur dingin pada pengujian TEG diperlukan sebuah sistem pengkondisi temperatur yang memanfaatkan peltier. Penelitian ini menggunakan metode eksperimen untuk mendapatkan karakteristik thermoelectric generator dengan jangkauan beda temperatur operasional 10.25-19.75 °C. Hasil penelitian menunjukkan penurunan tegangan rata-rata per menit sebesar 0.02 volt terjadi disebabkan penurunan beda temperatur sisi panas dan dingin rata-rata per menit sebesar 0.65 °C.
Pemeliharaan Sistem Fotovoltaik di Sekolah Menengah Kejuruan Muhammadiyah 2 Turi. Sleman Muhammad Nadjib; Fitroh Anugrah Kusuma Yudha
Berdikari: Jurnal Inovasi dan Penerapan Ipteks Vol 11, No 1 (2023): February
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/berdikari.v11i1.17330

Abstract

 SMK Muhammadiyah 2 Turi in Sleman Regency, Special Region of Yogyakarta, received photovoltaic system assistance from a government grant. Photovoltaic is a technology that converts solar energy into electrical energy. This equipment is used as a backup when the power is off. However, the partners did not understand how to maintain the photovoltaic system. The proposed solution was to conduct training on photovoltaic system maintenance. This activity aimed to provide knowledge for those in charge of operations on photovoltaic system maintenance methods. The applied method was tutorial/training and practice. The presented materials were photovoltaic technology, installation, and maintenance. The evaluation was to compare test results before and after training. The evaluation showed that this training increased participants' knowledge about photovoltaic systems by 25.29%. This training can be further developed in a community environment by adding photovoltaic installations in the vicinity. Communities should be able to carry out maintenance independently so that the performance of the photovoltaic system and the durability of its components are optimal.
Physical property analysis of biodiesel from nyamplung and used cooking oil: density, viscosity, calorific value, and flash point Wahyudi Wahyudi; Muhammad Nadjib; Achmad Faizi
Jurnal Polimesin Vol 22, No 2 (2024): April
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v22i2.4565

Abstract

The increasing dem and for energy and the depletion of fossil fuel shas led to the exploration of alternative fuels like biodiesel, which require sref inement tomatch diesel oil properties. This study investigates the combination of nyamplung oil, a non-edible potential source, with waste cooking oil for biodiesel production, aiming to improve its physical properties. Through a method ological approachin volving degumming, esterification, and transesterification, biodiesel was produce dfrom these oils in 11 different blend compositions. The physical properties of these blends, including density, viscosity, flashpoint, and calorific value, were rigorously tested. Results indicate that incorporating waste cooking oil into nyamplung biodiesel significantly reduces viscosity, density, and flashpoint while increasing the calorific value. Specifically, the addition of waste cooking oil altered the density from 912.74 kg/m³ in pure nyamplung biodiesel to 857.27 kg/m³, decreased the viscosity from 28.02 cStto 4.58 cSt, reduced the flash point from 223°C to 197°C, and increased the heating value from 7,626.59 cal/g to 8,348.94 cal/g.
Co-Authors Achmad Faizi Andre Sasuta Fitroh Anugrah Kusuma Yudha Joni Kasmara Marausna, Gaguk Muhammad Akhid Riza Thoharuddin Thoharuddin Tito Hadji Agung Santosa Wahyudi, Wahyudi