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All Journal Rotasi Semesta Teknika KAREBA : Jurnal Ilmu Komunikasi JMPM (Jurnal Material dan Proses Manufaktur) Turbo : Jurnal Program Studi Teknik Mesin Chemistry Indonesian Journal of Chemical Research Iqtishoduna: Jurnal Ekonomi Islam Humantech : Jurnal Ilmiah Multidisiplin Indonesia Eksergi: Jurnal Teknik Energi Jurnal Polimesin
Muhammad Nadjib, Muhammad
Universitas Muhammadiyah Yogyakarta
Religion Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Environmental Science Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Library & Information Science Materials Science & Nanotechnology Mechanical Engineering Public Health

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Journal : Semesta Teknika

 1 
Pemantauan Lapangan Sistem Penerangan Tenaga Surya 6 x 50 Wp di Sleman Nadjib, Muhammad
Jurnal Semesta Teknika Vol 14, No 2 (2011): NOVEMBER 2011
Publisher : Jurnal Semesta Teknika

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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 Nadjib, Muhammad
Jurnal Semesta Teknika Vol 15, No 1 (2012): MEI 2012
Publisher : Jurnal Semesta Teknika

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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.
Thermal Stratification Characteristics of Storage Tanks on Solar Water Heater Inserted with Latent Heat Material Nadjib, Muhammad; Wahyudi, Wahyudi; Santosa, Tito Hadji Agung; Hidayat, Yaafi
Semesta Teknika Vol 27, No 1 (2024): MEI
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v27i1.21753

Abstract

As a latent heat medium, phase change material (PCM) can be applied to heat storage for solar water heaters (SWH). The method used to place PCM is to put it in a capsule. Thermal stratification is critical in generating SWH thermal efficiency. Installation of horizontal capsules in the tank has no known effect on thermal stratification. This paper aims to study the thermal stratification in active-type SWH incorporating PCM. A cylindrical capsule containing the PCM was placed inside the tank. The thermocouple was installed on both the water and PCM sides. The charging process was conducted indoors, and the water flow rate varied from 1, 2, and 3 LPM. Water temperature data for each variation was analyzed to evaluate the thermal stratification. Richardson number analysis proved that thermal stratification was formed in all water flow rates. It was found that a low water flow rate results in high thermal stratification.
Investigasi Kapasitas Energi Termal pada Solar Water Heater Berbasis Kalor Laten dengan Variasi Debit Air Nadjib, Muhammad; Caroko, Novi; Thoharudin, Thoharudin; Darmawan, Hanifan
Semesta Teknika Vol 26, No 1 (2023): MEI
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v26i1.18196

Abstract

Material penyimpan kalor pada solar water heater adalah air sebagai kalor sensibel. Kekurangan air adalah densitas energinya rendah. Material lain adalah dari golongan kalor laten (phase change material, PCM) yang memiliki densitas energi tinggi. Unjuk kerja termal SWH tipe aktif dengan tangki horizontal dan memakai PCM jenis paraffin wax terhadap perubahan debit aliran air belum pernah diungkap. Tujuan penelitian ini adalah untuk mendapatkan karakteristik pengaruh perubahan debit air terhadap kapasitas penyimpanan energi termal di tangki. Penelitian menggunakan SWH dengan tangki yang di dalamnya diletakkan kapsul silinder berisi paraffin wax RT55. Termokopel dipasang di sisi air dan PCM. Eksperimen dilakukan secara indoor memakai solar simulator. Debit aliran air yang digunakan adalah 1 lpm, 2 lpm dan 3 lpm. Penelitian ini mendapatkan hasil yaitu kapasitas energi termal untuk debit aliran tersebut masing-masing adalah 10,45 MJ, 10,59 MJ dan 10,71 MJ. Semakin besar debit air maka kapasitas penyimpanan energi termal semakin tinggi.
Correlation between Physical Properties and Specific Fuel Consumption in Jatropha -Used Cooking Oil Biodiesel Mixtures Wahyudi, Wahyudi; Nadjib, Muhammad; Apriyanto, Apriyanto
Semesta Teknika Vol 26, No 2 (2023): NOVEMBER
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v26i2.20163

Abstract

This study was motivated by the need to understand the influence of using waste jatropha biodiesel on the physical properties of fuel and the performance of diesel engines. The primary aim was to determine the relationship between the fuel's physical properties, spray angle, and specific fuel consumption (SFC) at various load levels. The methodology employed included measurements of density, viscosity, flash point, calorific value, spray angle, and SFC for different blends of waste jatropha biodiesel and diesel (B5, B10, B15, B20). The research results demonstrate an increase in density, kinematic viscosity, and flash point, along with a decrease in calorific value, as the biodiesel content increases. The density of the biodiesel mixture ranges from 823 kg/m³ at B5 to 836.50 kg/m³ at B20. The kinematic viscosity increases from 3.9 cSt at B5 to 5.2 cSt at B20, and the flash point rises from 112.9°C at B5 to 128.7°C for B20. Meanwhile, the calorific value decreases from 10308.2670 cal/g at B5 to 10133.8280 cal/g for B20. A strong correlation exists between density and kinematic viscosity with the spray angle, exhibiting R2 values of 0.9141 and 0.8287, respectively. The correlation between the fuel's physical properties and the specific fuel consumption (SFC) is also substantial, marked by high R2 values above 0.93. These findings provide a solid foundation for the development of more optimal biodiesel formulations.
Co-Authors A.A. Ketut Agung Cahyawan W Aji, Yogi Purnomo Andi Alimuddin Unde, Andi Alimuddin Andi Batari Alimuddin, Andi Batari Andi Muhammad Rajanuddin, Andi Muhammad Andi Rivai Beta, Andi Rivai Anggara, Fajar Apriyanto, Apriyanto Arif Setyo Nugroho Asfah Rahman, Asfah Ayatullah, Maulana Wahyu Bambang Riyanta, Bambang Caroko, Novi Darmawan, Hanifan Decy Wahyuni, Decy Djabir Hamzah, Djabir Eka Mardariyanti, Eka Erna Areks, Erna Faizi, Achmad Hafied Cangara, Hafied Hidayat, Yaafi Ihsan Ihsan Kenny Monica Kemal Putri, Kenny Monica Kemal Kusuma Yudha, Fitroh Anugrah Majduddin, Muhammad Mariono, Mariono Maya Sari Muhammad Farid Mustati Mustati, Mustati Nevi Danila Nolvy Ruata, Nolvy Nur Asnawi Pambudi, M. Anugrah Rizky Pathur Razi Ansyah Prayogo, Nanda Rahmad Arsyad, Rahmad Ratna Ediati Santosa, Tito Hadji Agung Suhanan Suhanan, Suhanan Sunardi Sunardi Susetyorini, Jurit Tri Suyono, Warsito Kabul Thoharudin, Thoharudin Wahyudi Wahyudi Yati BT Samsuddin Yudha, Fitroh Anugrah Kusuma