Dr.Ir.Zuryati Djafar, MT - Profile on Academia.edu (original) (raw)

Papers by Dr.Ir.Zuryati Djafar, MT

Potential of seawater as a source of electrical energy based on electrochemical - Voltaic cells

Nucleation and Atmospheric Aerosols, 2023

Variable Step-Size Decremented Window-Size Scanning-based MPPT Algorithms for Thermoelectric Generator Systems

2018 2nd International Conference on Applied Electromagnetic Technology (AEMT)

Variable Step-Size Decremented Window-Size Scanning-based MPPT Algorithms for Thermoelectric Gene... more Variable Step-Size Decremented Window-Size Scanning-based MPPT Algorithms for Thermoelectric Generator Systems are presented in this paper. The proposed MPPT algorithm is simple to implement and can tune automatically the TEG system to operate at its maximum power point effectively. By using different step-size decrements and step-number changes for each scanning-step iteration, four types of DWS-based MPPT algorithms are derived. The performance of the four DWS algorithms are verified through simulations. The optimal or appropriate selection of the variable step-size decrements for each scanning-step iteration can improve the convergence speed of the algorithms to reach the expected maximum power points. The DWS-based MPPT algorithm, which uses for example a 13-4-1 step-size decrement with 1% minimum duty-ratio step-size, can reach the maximum power point after 22 P&O-steps. The need for relatively small number of the required P&O-steps, in addition to the simple computing implementation, is the impressive features of the proposed DWS-based MPPT algorithms for thermoelectric-based energy harvesting applications.

Analisis Kelayakan Kondensat Sistem Pengkondisian Udara (AC) sebagai Air Minum

Experimental Test of the Thermoelectric Performance on the Dispenser Cooler

Analisis Waktu dan Biaya Pemakaian Briket Blotong sebagai Bahan Bakar Rumah Tangga

The Performance of Clay Furnace with Variation in the Diameters of the Briquette Burning Chamber

IOP Conference Series: Materials Science and Engineering, 2020

Biomass fuel is an alternative energy source used in the form of briquettes using clay stoves. Ut... more Biomass fuel is an alternative energy source used in the form of briquettes using clay stoves. Utilization of clay as a briquette stove often results are not satisfactory as is the use of other fuel stoves, this is because the amount of air in the furnace burning chamber has not been determined and focused properly, so the purpose of this study is to determine the thermal efficiency of the furnace at variations in the diameter of the aluminum sleeve in the furnace burning chamber. The method used is to test 5 variations in diameter of the furnace burning chamber (cylinder). The results showed the best thermal efficiency was obtained at 52.87% at 180 mm slab diameter, boiling time at 9 minutes, with a heat loss of only 2.02 kW.

A New Simulation of Photovoltaic and Thermoelectric Generator Hybrid System with a Beam Splitter Cold and Hot Mirror for Low Intensity

International Review of Mechanical Engineering (IREME), 2019

In this study, the simulation of Photovoltaic (PV) and Thermoelectric Generator (TEG) hybrid was ... more In this study, the simulation of Photovoltaic (PV) and Thermoelectric Generator (TEG) hybrid was developed using a spectrum splitter. The simulation was carried out by using the AM1.5G solar spectrum as a standard for 1 Sun, with a variation of 0.05, 0.1, 0.25, 0.50, and 0.7 Suns. The light spectrum was concentrated by using a Fresnel lens and then transmitted to a spectrum splitter. Spectrum splitter that was used is a hot and cold mirror with dimensions of 50 × 50 mm, which is positioned at the angle of 45o from the Fresnel lens’s direction. Additionally, PV used is a type amorphous Silicon (a-Si) and TEG types of Bismuth telluride (Bi2Te3). The simulation result shows that by using a cold mirror, its maximum total power is better than a hot mirror. In addition, the Suns and temperature changes have a significant effect on the output power and efficiency of the hybrid. Particularly at 0.7 suns, 25 °C PV temperature, and 55 °C hot-side temperature of TEG, the power obtained was 0.096 W/m2, and the efficiency was 50.37% compared to the hot mirror, which is relatively lower, accounted for 0.094 W/m2 and 48.07%.

Journal of Physics: Conference Series, 2018

Chemical and physical properties of Rice Husk as a potential energy resource were analyzed by mea... more Chemical and physical properties of Rice Husk as a potential energy resource were analyzed by means Fourier transform infrared (FTIR), x-ray diffraction (XRD), scanning electron microscope (SEM), and energy disperse spectroscopy (EDS). Rice husk is heated with varied temperature of 250˚C, 350˚C, 450˚C and 30, 60, 90 minutes respectively combine with time variation. The results show that the calorific value decreases whenever the temperature and time increase. The heating time of 30 minutes at 250˚C of temperature gives calorific value of 10.4 MJ/Kg. While at the 450˚C of temperature, the calorific value decrease to 4.7 MJ/Kg. The EDS shows that the time of heating is an important parameter where carbon and nitrogen were decreasing with the increment of the heating time while the oxygen increase when the heating time increase. The XRD shows that the broad (002) reflections between 20 o and 30 o indicate carbon disordered with small domains of coherent and parallel stacking of the graphene sheets, which consists of surface morphology from SEM. FTIR shows that the O-H stretching pronounced at around 3452 cm -1 and 3412 cm -1 and pronounced clearly at the highest temperature. The aromatic group from lignin gives rise to C=C asymmetric stretching at cm -1 as a G band corresponds to the sp2-hybradization bonding of carbon atoms and C-H bending modes at 2927 at 796 cm -1 . This results of the characteristic of chemical and physical properties of the rice husk examination provide the prominent source of useful energy that can eventually replace the fossil fuel.

Heat and technology, Feb 29, 2024

Data centers, serving as vital support infrastructure for telecommunications and data storage sys... more Data centers, serving as vital support infrastructure for telecommunications and data storage systems, allocate nearly half of their total electricity consumption -approximately 50% -to cooling systems for temperature and humidity regulation. Enhancing the efficiency of these systems is crucial for energy conservation and reducing operational costs in data centers. In this regard, the integration of flexible heat pipes presents a promising solution for alleviating the data center's heat load. Heat pipes, as passive cooling system technologies, function by absorbing heat on one side while simultaneously releasing it on the other. Strategically positioned in the air ducts subsequent to the data server, these pipes aim to lower the air temperature, thereby reducing the burden on the cooling system. This study focuses on evaluating the effectiveness of heat pipes in transferring heat from the air within hot air ducts, considering variables such as the density distance between the pipes and their operating tilt angle. Distances between the heat pipes vary from 3 mm to 6 mm, with tilt angles set at 0°, 15°, and 30°. The results reveal that lower density distances lead to higher heat ab sorption; specifically, for a slope of 0°, densities of 6 mm, 5 mm, 4 mm, and 3 mm correspond to heat absorptions of 2.749 kW, 2.545 kW, 2.448 kW, and 2.358 kW, respectively. Additionally, smaller tilt angles result in greater heat absorption, with a 3 mm density at slopes of 30°, 15°, and 0° yielding 2.017 kW, 2.125 kW, and 2.749 kW, respectively. Optimal heat transfer occurs at a density of 3mm and a slope of 0°, where the heat pipe can transfer 2.749 kW of heat out of the cooling system and reduce the temperature of the air flowing through it by 13℃.

Protek: Jurnal Ilmiah Teknik Elektro, Sep 3, 2023

The intensity of solar energy is an important factor in viewing the performance of the thermoelec... more The intensity of solar energy is an important factor in viewing the performance of the thermoelectric generator (TEG). Most studies only look at the effect of treatment on the TEG module in the form of cooling mode and its materials. Therefore this study examines the effect of the solar intensity value on the magnitude of the module voltage. On the hot side of the module are placed heat absorber plates of copper, Fe and aluminum plates as well as non collector plates. Modules are cascaded and connected in series as many as 14 modules per plate, so that a total of 56 TEG modules are used. Data collection is carried out simultaneously on all plates. The test results show that the increase in solar intensity is liner with the magnitude of the TEG module voltage or in other words the correlation is positive. The data also shows that copper collector plates produce the highest voltage difference, followed by Ferro, Alumina and no-plates at ∆V 0.871, 0.805; 0.369 and 0.153 V, respectively.

International Journal of Design & Nature and Ecodynamics, Aug 30, 2023

Given Indonesia's average atmospheric humidity of 75% to 85%, this study explores the potential o... more Given Indonesia's average atmospheric humidity of 75% to 85%, this study explores the potential of atmospheric air as an alternative clean water source to mitigate water shortage. The research employs a thermoelectric cooler (TEC 1-12706), supplemented with a heatsink and fan on its hot side to enhance heat dissipation. A copper-made cooling coil serves as both a heat absorber and a condenser for atmospheric air passing through it. The cooling source for the coil (diameter=7.9mm; length=1000mm) is derived from a waterblock attached to the cooler's cold side. Experiments were conducted across three environmental conditions: laboratory, residential area, and coastal area, with the air flow rate of the heatsink cooling fan varied. Data collection spanned a humidity range of 72.27%-83.01%. Findings revealed a direct correlation between the air mass flow rate of the heatsink cooling fan and the amount of water extractable from the air. In initial testing at the Laboratory, at a mass flow rate of 0.046 kg/s it produced 4.25 ml/hour and at 0.069 kg/s it produced 4.625 ml/hour and at 0.092 kg/s it produced 5.5 ml/hour. Furthermore, from the three environmental conditions tested, more water can be extracted on the coast than in laboratories and residential areas. In coastal areas, the air mass flow rate is 0.092 kg/s, water that could be extracted is 7.75 ml/hour, while in the laboratory environment it is 5.5 ml/hour and in residential areas it is 4.75 ml/hour. These promising results encourage further research to augment water extraction by maximizing the contact surface between the air cooler and the coil surface, potentially offering a viable solution for clean water shortage.

EPI International Journal of Engineering

The refrigeration system used to meet the needs of human life can be in the form of a thermoelect... more The refrigeration system used to meet the needs of human life can be in the form of a thermoelectric cooler (TEC). Due to its small volume, environmental friendliness and several other advantages, TEC can be widely applied such as in fish cooler box. In this study, the cooler box used had dimensions of 290mm x 205mm x 254mm and were given twelve stacked 3 TEC modules with varied DC voltages. The purpose of this study is to determine the voltage that can provide the best TEC performance. This performance will be indicated by the Coefficient of Performance (COP) value of each voltage variation. The experimental results show that the best performance of the TEC is at 42 Volts. The lowest temperature achieved during the experiment was 7.74℃ on the cold-side.

PROtek : Jurnal Ilmiah Teknik Elektro

Biomass briquette stove is a cooking tool that is still widely used by the people of the interior... more Biomass briquette stove is a cooking tool that is still widely used by the people of the interior of South Sulawesi. Even in urban areas, it is not uncommon to find their use because of the ease of obtaining briquettes and its relatively good efficiency. This study aims to determine the best performance of a biomass stove from three types of clay material stove shapes in different configurations of geothermal variations. The three variations of the geometric shape of the stove are cylindrical, rectangular and hexagonal using biomass material from coconut shell charcoal in the shape of a honeycomb with an inner diameter of 15 mm and an outer diameter of 65 mm and a height of 45 mm. The uniqueness of this stove is the addition of a sleeve diameter of 180mm in the stove's combustion chamber as heat insulation so that the combustion process in the combustion chamber can be more perfect. The test results show that the presence of a flat surface on the stove wall will accelerate heat ...

EPI International Journal of Engineering

This study was conducted to obtain the angle of elevation of solar panels (PV) to harvest photon ... more This study was conducted to obtain the angle of elevation of solar panels (PV) to harvest photon light energy sources from LED bulbs that are often used in residential homes or buildings. The PV tilt angles tested are 0, 15, 30 and 90º by placing a constant bulb in its position. The results of the observations show that a slope of 0º produces the highest PV electrical power, although it is not significant compared to the other 3 slope angles. The decrease in PV output power occurs when the slope angle increases. Optimum power of 16.93 Watt is obtained by using a Hannochs bulb at a power of 15 Watt with an angle of elevation of 0º. Furthermore, the power decreased to 16.33, 12.92, and 12.91 Watts at angles of 15, 30 and 90º, respectively. Further research is still needed by increasing the variation of bulb power above 15 Watts to validate the position of the PV panels on the walls of the building according to light source.

International Journal of Engineering, 2017

The main power source of motor vehicle is combustion engines which use fossil fuels (diesel, gaso... more The main power source of motor vehicle is combustion engines which use fossil fuels (diesel, gasoline, pertamax etc.) as fuel. The total heat supplied to the engine in the form of fuel, 30-40% of fuel is converted into mechanical work, heat remaining is released through the exhaust pipe and the engine cooling system. The unused heat source in motor vehicles could potentially be used to generate electricity as a supplier of electricity needs in a vehicle. The technology used to convert the heat energy into electrical energy known as the thermoelectric generator, which uses the Seebeck theory as the basis of the principle works. This study uses a cylinder with a heating element inside (heater) as a heat source such as the exhaust pipes designed in a motor vehicle. Cylinder temperature is simulated as the temperature of the exhaust pipes of motor vehicles by varying the input voltage supplied to the heater (150V, 175V, 200V and 225V). This study also uses sub-sonic wind tunnel as a sou...

Analisis Termoekonomi pemasakan kompor briket, LPG dan Minyak Tanah

Pengaruh Perlakuan Permukaan Serat Alam Rami (Boehmeria Nivea) Terhadap Wettability Dan Kemampuan Rekat Matrik Epoxy Resin

Jurnal Penelitian ENJINIRING, 2010

Jitrnal Penelitian Enj iniring ISSN: 1411-6243 Vol. 12, No. 2, Tahun 2009 hai. 129-134 Pengaruh P... more Jitrnal Penelitian Enj iniring ISSN: 1411-6243 Vol. 12, No. 2, Tahun 2009 hai. 129-134 Pengaruh Perlakuan Permukaan Serat Alam Rami {Boehmería Nivea) terhadap Wettability dan Kemampuan Rekat Matrik Epoxy Resin Zulkifli Djafar & Onny S. Sutresman Jurusan Teknik Mesin ...

Performance analysis of sea wave power plant oscillating water column system (SWPP-OWC)

Nucleation and Atmospheric Aerosols, 2022

Performance analysis of sea wave power plant oscillating water column system (SWPP-OWC)

Nucleation and Atmospheric Aerosols, 2022