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The object of this research is to compare the performance of Stairmand and Lapple type cyclone separators. The main problem to be solved in this research is determining which Stairmand or Lapple type cyclone separator is more suitable for integration into the pyrolysis system. The comparison is based on key performance indicators: pressure drop and collecting efficiency. The research findings indicate that both Stairmand and Lapple cyclone separators exhibit similar trends in pressure drop and collecting efficiency. As inlet velocity increases, the pressure drop also increases for both types. However, the collecting efficiency initially rises but then declines when inlet velocities exceed 13 m/s. The Lapple variant achieved a peak collecting efficiency of 98.94 % and pressure drop 16.26 mbar at an inlet velocity of 13 m/s, whereas the Stairmand design reached 97.33 % and pressure drop 12.16 mbar at 13 m/s inlet velocity. The Lapple type cyclone separator outperformed the Stairmand type in terms of both of pressure drop and collecting efficiency. This superiority is attributed to the specific design features and characteristics of the Lapple type. The superior performance of the Lapple type cyclone separator can be explained by its unique design elements that contribute to improved particulate matter separation and pressure drop. These elements may include differences in cylinder height and particulate matter outlet diameter. Based on the findings of this research, the Lapple type cyclone separator is recommended for integration into pyrolysis systems. However, it is important to consider the specific operating conditions of the pyrolysis process, such as temperature, the particulate matter size distribution, flow rate, and desired separation efficiency [ABSTRACT FROM AUTHOR]

Bio-lubricants are the future of lubricants as a substitute for mineral lubricants; however, bio-lubricants have drawbacks, such as poor thermal-oxidative stability. In addition, during the friction process, the temperature of the lubricant increases, so the lubricant must have good thermal conductivity to conduct heat to the environment. To combat the drawbacks of bio-lubricants, some additives have been used to improve their performance as lubricants. Composites of carboxymethyl cellulose (CMC)/MXene and Span 60 as surfactants were used as additives in CPO with different compositions. The physicochemical properties of the addition of CMC/MXene and Span 60 in CPO have changed, including kinematic viscosity, TAN, thermal conductivity, and fatty acids, which have a positive impact on lubrication performance in terms of reducing oxidation processes and increasing thermal conductivity. From fatty acid composition tests and FTIR analysis, the additives work to suppress the oxidation process. A pin-on-disk test was performed to evaluate the tribological performances of bio-lubricants. The results show that CM 10 SP (0.5% wt of CMC and MXene and 1% wt Span 60) demonstrated a significant decrease in CoF and wear rate by 49% and 74%, respectively, at a load of 50 N and a speed of 1400 rpm compared to CPO without additives. An interface layer of CMC/MXene and Span 60, separating two surfaces, could induce wear on the surface of the disk and pin. [ABSTRACT FROM AUTHOR]

The encapsulation of stem cells into alginate microspheres is an important aspect of tissue engineering or bioprinting which ensures cell growth and development. We previously demonstrated the encapsulation of stem cells using the hanging drop method. However, this conventional process takes a relatively long time and only produces a small-volume droplet. Here, an experimental approach for alginate emulsification in multistage microfluidics is reported. By using the microfluidic method, the emulsification of alginate in oil can be manipulated by tuning the flow rate for both phases. Two-step droplet emulsification is conducted in a series of polycarbonate and polydimethylsiloxane microfluidic chips. Multistage emulsification of alginate for stem cell encapsulation has been successfully reported in this study under certain flow rates. Fundamental non-dimensional numbers such as Reynolds and capillary are used to evaluate the effect of flow rate on the emulsification process. Reynolds numbers of around 0.5–2.5 for alginate/water and 0.05–0.2 for oil phases were generated in the current study. The capillary number had a maximum value of 0.018 to ensure the formation of plug flow. By using the multistage emulsification system, the flow rates of each process can be tuned independently, offering a wider range of droplet sizes that can be produced. A final droplet size of 500–1000 µm can be produced using flow rates of 0.1–0.5 mL/h and 0.7–2.4 mL/h for the first stage and second stage, respectively. [ABSTRACT FROM AUTHOR]

It is necessary to utilize desalination technology to clear the water available, including seawater, to meet the increasing need for clean water due to population growth. Several desalination methods, such as thermal methods, membranes, freezing g, and ion exchange, continue to be developed but have not overcome some deficiencies. Therefore, new alternative desalination methods with droplet atomization, which utilizes the air entrainment phenomena, are being developed. Research on non-dimensional fluid atomization is the basis for designing this method. The study used brine pumped through a nozzle with a small diameter to become mist or vapor. This study carried out variations of research parameters on the configuration of the experimental apparatus in the form of pressure, the diameter of the nozzle, and the number of nozzles. Quantitative data from experimental results obtained from measurement instruments and qualitative data in videos obtained using a camera are to be processed into quantitative data using image processing. The results showed that pressure affects the characteristics of a full cone-shaped water spray. It was found that the best spray system configuration with two nozzles with a diameter of 0.5 mm in a pressure of 9 bar. [ABSTRACT FROM AUTHOR]

Ocean current energy is a promising and reliable resource that offers sustainability and predictability in realizing green future needs. A diffuser-augmented horizontal-axis turbine is utilized to generate ocean current energy. A numerical study on the impact of diffuser angle variations on the power coefficient has been carried out in the previous research. To elucidate the fluid dynamics aspects and further validation of previous computational results, the experimental investigation on the optimal design of tidal turbine with 20.04° diffuser augmentation is presented in this study. The study was conducted in a flowing tank with a current velocity of 0.7 m/s. The maximum power coefficient of 20.04° is 0.436 experimentally, which is a little smaller than the numerical value. Moreover, to reinforce the 20.04° result, a diffuser with an angle of 10.43° was also manufactured and tested experimentally. The maximum power coefficient of 10.43° is 0.303 experimentally, which is 3% smaller than the numerical value. It was concluded that the numerical approach might be considered satisfactory and represent similar phenomena to the experimental investigation in an application for modelling of multi-objective optimization. [ABSTRACT FROM AUTHOR]

Loop heat pipe (LHP) is an effective two-phase heat transfer device that utilizes evaporation and condensation of a working fluid. LHP is widely used in a passive cooling system, highly reliable and a very high thermal conductive device. However, extreme power density can cause dry-out in the evaporator section of LHP and might hinder the performance of the cooling system. The purpose of this research is to design and manufacture a new prototype of LHP by modifying the conventional LHP. The modification was performed by adding a diaphragm pump, called hybrid loop heat pipe (HLHP). The experimental results show that the installation of pumps in the modified LHP was able to prevent the occurrence of a dry out and reduce the operating temperature. Under a constant conductance mode, the pump was activated for 20 minutes and succeded in forcing the system to a new stable condition with a significant temperature drop. These results indicate that HLHP is very promising as a two-phase cooling system that can be proposed for devices that produce high heat flux. [ABSTRACT FROM AUTHOR]

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The enhancement of heat transfer performance in heat exchanger is achieved by reducing the size of the hydraulic diameter or by using a working fluid that has a better thermal conductivity compared to conventional working fluids. The application of a small hydraulic diameter can be found in the microchannel heat exchanger (MCHE). The design and the testing of the MCHE were done in this research. The MCHE was tested with several working fluids, such as the distilled water, the Al2O3-water nanofluids at 1%, 3% and 5% volume concentration, and the SnO2-water nanofluids at 1% volume concentration. The temperature of inlet and outlet were set at 50°C and 25°C, respectively. The variations of flow rate at the inlet were applied from 100 ml/min up to 300 ml/min. The addition of nanoparticle in the base fluid was proven to improve the heat transfer of the MCHE, the 5% Al2O3-water and 1% SnO2-water nanofluids are able to absorb the heat 9% and 12% higher than the base fluid. The overall heat transfer coefficient of MCHE with 5% Al2O3-water and 1% SnO2-water nanofluids were 13% and 14% higher than the base fluid. [ABSTRACT FROM AUTHOR]