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This paper discusses an attempt to compares the electrical characteristics of two solar modules of the same type and size in which one of the solar modules at the bottom is mounted a copper pipe for circulating water (as call photovoltaic thermal). The research was steered to observe water cooling effect to electrical characteristics of PV module. This system serves as a heat absorption on the bottom of the solar module. The experiment is conducted at the same time, place, and sunlight intensity conditions for both solar modules. The characteristics of short-circuit current, open circuit voltage, upper and lower temperature and the irradiation of sunlight from the two solar modules are observed. The test results show that photovoltaic thermal generate greater electrical power than solar modules not equipped with heat absorption

This experimental study aims to analyse the performance of sorted coffee beans-based biodiesel. This study is carried out in three main stages; (a) the preparation process of coffee beans raw material, (b) the biodiesel formation process, and (c) biodiesel performance analysis. In manufacturing process, the coffee bean powder is added with two chemical treatments sequentially; extraction-distillation and esterification/transesterification. Parameters of analysis in this study are the characteristics of the biodiesel and the performance of the biodiesel-diesel mixture in terms of fuel consumption efficiency and engine smoke opacity. Measurements of Engine Running Time (ERT) and smoke opacity were carried out on a single-piston diesel engine. There were five biodiesel-diesel mixture specimens; B0, B5, B10, B15, and B20 (20% biodiesel fraction). The experimental results show that mixing biodiesel with diesel fuel provides two main advantages; extending engine running time which means fuel consumption efficiency, and lowering the smoke opacity level. Therefore, it is more environmentally friendly. The efficiency of fuel consumption and smoke opacity depends on the biodiesel fraction in the fuel mixture. The results and methodology of this research are expected to be an additional reference in the development of biodiesel as an alternative fuel.

This experimental study intent to design and to analyse the passive cooling effect of an Earth-Air Heat Exchanger (EAHE) integrated into the building ventilation system. For hot climate regions, ground thermal inertia can be used as a passive cooling strategy in the building ventilation where the air supply comes from outside with hot temperature. The proposed EAHE device consists of two main-components; a water tank and a PVC hose as a heat-exchanger between air and water in the tank. Fresh air from outside with a flow rate of 5.63 kg. min -1 is blown through a 2 ½-inch PVC hose, and cooled by the low water-soil temperature before being distributed into the room. To analyze the effectiveness of the passive cooling effect, measurements are performed for several parameters; inlet and outlet air temperature of ventilation ducts and indoor-outdoor air temperature using a multichannel thermocouple data logger for 48 hours of measurement time. The results present that the EAHE device can reduce the air temperature to a maximum of 10.6 °C. This proposed EAHE device presents good performance as a passive cooling technique for a building ventilation system, especially during the day.

Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding properties. Among all types of cellulose materials available, cellulose nanofiber (CNF) has great potential to be utilized in a diverse range of applications, including as a film material. In this study, CNF biocomposite film was prepared by using polyvinyl alcohol (PVA) as a matrix and Uncaria gambir extract as a filler. This study aims to investigate the effect of Uncaria gambir extract on the optical properties and thermal stability of the produced film. The formation of the CNF biocomposite films was confirmed using Fourier Transform Infrared Spectroscopy, their transmittance characteristics were measured using UV-Vis spectroscopy and a transmittance meter, while their reflectance was determined using a reflectance meter. The results revealed that the addition of Uncaria gambir extract to the CNF biocomposite film improved its UV-shielding properties, as indicated by the lower percentage of transmittance in the visible region, 10%–70%. In addition, its reflectance increased to 10.6% compared to the CNF film without the addition of Uncaria gambir extract. Furthermore, the thermal stability of the CNF biocomposite film with the addition of Uncaria gambir extract improved to around 400°C–500°C. In conclusion, the results showed that CNF biocomposite film prepared by adding Uncaria gambir extract can be a promising candidate for optical and thermal management materials.

The current scarcity of fossil fuels requires the use of alternative fuels in motor fuels, especially diesel engines and gasoline engines. One of the alternative fuels used in plant-based internal combustion engines is biodiesel fuel produced from palm oil. A comprehensive analysis is needed with the use of crude palm oil (CPO) biodiesel fuel because it still causes decreased diesel engine performances. The purpose of this study was to determine the impact of using crude palm oil biodiesel fuel on performance of diesel engine. The research method was carried out experimentally on a diesel engine by comparing the performance of engines using pure biodiesel (B100) and biodiesel (B30) fuels from CPO fuel and compared with diesel fuel (B0) as a control parameter tested by varying the engine loads. The results showed that pure biodiesel fuel (B100) can be used in diesel engines, especially in biodiesel fuel (B30) even though the engine performance is still below diesel fuel (B0). This is marked by the power of 4.24 kW and torque of 19.83 Nm at a high engine load. The use of biodiesel fuel also causes reduced thermal efficiency and increased specific fuel consumption (SFC).

The indoor temperature in public buildings varies according to its internal loads scenario. In fact, this building typology in temperate climates is generally non-air conditioned and naturally ventilated. In order to improve indoor thermal conditions with appropriate solutions, it is necessary to study the vertical temperature profile. The main objective of this study is to show the impact of thermal stratification on thermal comfort of public buildings. The thermo-airodynamic modeling using TRNSYS(C) and CONTAM(C) have been performed in this numerical simulation study. The indoor air volume is vertically subdivided into several levels to evaluate the evolution of temperature profile taking into account the different inside-outside air exchange and air coupling between sub-zones. This study is performed in the city of Morocco that represents Mediterranean climate region with a moderate temperature. The effect of several parameters, such as indoor occupation pattern, internal lighting, sub-zones air exchange and vertical thermal stratification are studied. Numerical simulation results show that thermal stratification of buildings affects the occupant's comfort level

This study examines the effectiveness of static and dynamic PV module models for solar energy gathering. The static design of the first solar panel is used, while the dynamic design of the second solar panel with a single-axis tracker is used. Finding the best model for capturing solar energy and turning it into electrical energy is the aim. Monitoring systems use IoT technologies. To detect variables including current, voltage, radiation, temperature, and humidity, the system has a number of sensors. The Thinger i.o program, coupled to the Arduino Uno used to control these sensors uses the Internet of Things (IoT) concept to evaluate and keep track of the outcomes of parameter measurements. As a result, the acquired measurement results can be viewed on the Thinger i.o application and checked remotely from any location. The three tests show that systems using dynamic ideas are better able to capture solar energy than static systems. The performance discrepancy is at its widest in the third test, when the dynamic system generates 14.4% more electrical energy than the static system.

The ducting system is made up of 90° elbows and a few other fittings and accessories in addition to straight ducts. The friction loss, separation loss, and secondary flow loss are the main causes of the pressure decrease in an elbow, and they all increase with the presence of elbows. Utilizing too much energy to propel the flow is a cost associated with pressure loss. The aim of this research is to investigate turbulent flow via 90° square elbows and a square-sectioned duct through experimental methods by adding a circular turbulator (CT) close to the elbow wall's inner radius. The Reynolds numbers (ReDh) used in this research are 1.6×104, 4.8×104, and 9.5×104, with average flow velocities of 2 m/s, 6 m/s, and 12 m/s. Circular turbulators are added to the inner walls with angular positions (α) of 5°, 10°, 15°, and 20°. The results showed that the turbulence intensity increased toward the inner radius wall of the elbow in ducting with CT. For this study, the flow within the ducting with the CT is generally more turbulent than the flow inside the ducting without the CT. By including CT, it was possible to reduce the overall pressure loss in ducting with an elbow. The pressure reduction at two ReDh values (1.6×104 and 4.8×104) was only lessened by CT positioned at α=10°, 15°, and 20° out of the four CT placements. Conversely, CT positioned at α=5° can only effectively mitigate pressure decrease at ReDh=1.6×104. CT installation cannot lessen the pressure drop that happens in the ducting at a value of ReDh=9.5×104. CT placement at the three α values often helps to lower the pressure drop in the ducting. Using the CT, positioned at α=15°, is the greatest strategy to reduce the overall pressure decrease

This experimental study aims to investigate and analyze the performance of a Water-Air Heat Exchanger that functions as passive cooling in a building ventilation system in the tropics. Before being blown into the room, the high-temperature outdoor air will be passively cooled by the lower-temperature water. Air driven by an Inline Duct Fan with a constant mass flow rate of 4.68 cubic meters per minute flows through a PVC hose as a heat exchanger inserted into a full water reservoir with a diameter of 100 cm and a height of 110 cm. A heat exchanger hose with a diameter of 6.35 cm and a length of 4130 cm is installed in a spiral-circular manner with a total of 16 coils with a diameter of 80 cm to increase the heat transfer effectiveness between water and air. The passive cooling effectiveness is analyzed by decreasing the air temperature between the inlet and outlet of the ventilator after passing through the heat exchanger. The temperature, humidity, and daylight measurement data were carried out for 36 consecutive hours using a multichannel data logger at several locations; ventilator inlet, ventilator outlet, water in the tub, and outside air. The measurement results show that the designed water-to-air heat exchanger provides a significant passive cooling effect and can reduce air temperature to 6.88 °C. By utilizing the passive cooling effect, the cooling energy gain obtained during the measurement period in the ventilation system of this building is 8.3 kWh. The methodology and results of this research are expected to make a positive contribution to the development of the concept of energy-efficient buildings by using passive cooling techniques