Performance of force circulation cross-matrix absorber solar heater integrated with latent heat energy storage material

The utilization of thermal energy storage in the thermal absorber applications has been increasingly important especially in the application where there is a mismatch between energy demand and energy supply. This technology implies that the heat is stored during charging or discharging process through melting and freezing of the thermal energy storage material so that it can be used in the future. This paper presents the outcome of the experimental investigation on the performance of cross-matrix absorber (CMA) utilizing paraffin as the thermal energy storage material. Experiments were carried out by exposing the CMA under different artificial solar radiation (300 W/m2, 500 W/m2, 700 W/m2 and 900 W/m2) for 30 minutes followed by 30 minutes of discharging process. Based on the observation, it was found that smaller mass flow rate value of 0.005 kg/s gave the highest temperature output regardless of the intensity of solar radiation as compared to the other after 30 minutes of charging process. In terms of heat gain by the thermal absorber, it was concluded that the highest mass flow rate of 0.01 kg/s passing through the absorber lead to the higher heat gain by the CMA, hence prolonged the cooling down / discharging period as shows by the result, where case with maximum mass flow rate (0.01 kg/s) consistently contributed to the higher heat gain by the absorber. This feature is very useful in the solar thermal collector related applications such as crop drying and domestic building heating. The heat gain by the absorber is also contributed by the intensity of the solar radiation

Blue Ocean Swimming Pool Service Center / Mohd Nasri A. Manan ... [et al.]

The business that establish is shareholder that depend on the shareholder act 1961. The business had been registered on the name of Blue Ocean Swimming Pool Service Center that address at No, 46G, Jalan. 27/70A Desa Sri Hartamas, 50480 Kuala Lumpur Business start operation on the 1st January 2002 that will focus on service of cleaning and maintenance swimming pool. This business is among four shareholder members that sponsor between RM 20,000 to RM14,000 each. We also had made a loan from Perwira Affin Bank to add our capitol. The total of loan that we made was RM 100,000

Immunological studies on nucleic-acids and their components .5. Antibodies specific to a deoxyribodinucleotide sequence

Antibodies were raised in rabbits against the bovine serum albumin conjugate of dpApT. Analysis by double diffusion in agar gel and quantitative precipitation test showed the presence of antibodies specific to the hapten in the antisera. Quantitative data on the specificity of the antibodies were obtained by studying the inhibition of the binding of 3H-dpApT to the anti-sera by various nonradioactive mono- and oligonucleotides, using a nitrocellulose membrane binding assay. The antibodies were found to be highly specific for the dinucleotide sequence dpApT. The antibodies were able to bind to synthetic oligonucleotides containing the sequence dpApT and to denatured calf thymus DNA

Characteristics of solar thermal absorber materials for cross absorber design in solar air collector

The solar thermal absorber is an integral component of a solar air collector, especially in determining the overall performance of a solar air thermal system. The type and shape of material will have a direct impact on the operating temperature and thermal energy storage effect of the solar air thermal collector. This paper focused on the investigation of aluminum and stainless steel hollow square rods in terms of their solar thermal absorber performance. Comparisons between different materials and coatings were conducted in order to determine their impact in solar thermal absorber applications. Experiments were conducted on both materials with flat-black coated and non-coated surfaces of aluminum (6063) and stainless steel sets respectively. Both sets were exposed under 585 W/m2 radiation and the temperature response was recorded. A significant improvement was shown to result from the application of flat-black coating against non-coated material, with maximum temperatures of 67.2oC and 48.3oC respectively. It was observed that for the hollow square metal absorber the heating and cooling characteristics can be established by means of the relation between the surface and inner air temperatures of the absorber. This method can assist in temperature profiling of hollow square metal for solar thermal application

A Review of Seaport Microgrids for Green Maritime Transportation: The Shore and the Seaside

Emerging from the field of microgrids is an efficient and persuasive transitional technology with great promise for easing energy crises, environmental worries, and economic limitations in seaports. When it comes to high-performance ports, this technology becomes even more important. One example is smart ports, which use state-of-the-art ICT applications to completely revamp container and vessel management. Strengthening national economic sustainability and global competitiveness are both impacted by this invention. Reducing the environmental impact of the maritime transport business is no easy feat. In this study, we take a look at how seaport microgrids are becoming more important in the quest for environmentally friendly marine transportation. We take a look at the major problems that contemporary seaports are facing, such as the ever-increasing need for energy, the contamination of both the air and water from ship emissions and the unpredictable cost of electricity. The goal is to bring together current information about smarter ports by giving examples and to encourage new ideas and research in this field. As part of our efforts to inspire new research into smart port development, we also outline certain open questions that need answering. This report could serve as a valuable resource for future research on seaport microgrids

A performance and technoeconomic study of different geometrical designs of compact single-pass cross-matrix solar air collector with square-tube absorbers

This manuscript presents a performance study on a forced convection single-pass solar air heater channel with compact cross-matrix absorber (CMA) incorporating metal hollow square-tube absorbers. Four different geometries of CMA (Type I, II, III and IV) were investigated experimentally to evaluate their efficiency, pressure drops and heat transfer parameters. The experiments were conducted with uniform heat flux (indoor) and outdoor solar radiation as heat source. The air mass flow rates used were between 0.0142 kg/s and 0.0360 kg/s. Techno-economic feasibility studies were conducted using cost-benefit ratio (AC/AEG) method. Thermal efficiency of the CMA obtained by Type I with 76%, being the highest. CMA Type I also exhibited the highest temperature elevation than other configurations with 15.3 °C and thermal capacity of 38.7 kJ. Maximum pressure drop obtained was 1.33 Pa in turbulent condition with Reynolds number of 50,794. Type I has the advantage of high performance CMA and has comparatively lower cost-benefit ratio (AC/AEG) of 0.15 RM/kWh than other type of thermal absorbers

A review of water heating system for solar energy applications

Solar energy is one of the widely used renewable energy that can be harnessed either by directly deriving energy from sunlight or indirectly. Solar water heating system, on the other hand, is one of the applications of solar energy that has drawn great attention among researchers in this field. Solar collectors, storage tanks and heat transfer fluids are the three core components in solar water heater applications, which are reviewed in this paper. This paper discusses the latest developments and advancement of a solar water heater based on the three basic components that may affect the thermal performance of the system. It also reviews the development of various types of solar collectors in solar water heater, including both the non-concentrating collectors (flat plate collector, evacuated tube collector) and the concentrating collectors (parabolic dish reflector, parabolic trough collector). All these are studied in terms of optical optimization, heat loss reduction, heat recuperation enhancement and different sun tracking mechanisms. Among the non-concentrating and concentrating collectors, the parabolic dish reflector collectors show the best overall performance. The use of nanofluids as a heat transfer fluid was also discovered in this pape

Review on matrix thermal absorber designs for solar air collector

Solar thermal absorber is the main component of solar air collector. It absorbs solar radiation and converting energy received to thermal energy and transferring the energy by means of convection to working fluid, producing elevated air temperature output. Among thermal absorber used in solar air collector applications, permeable matrix thermal absorber is one of the promising thermal absorbers that delivers high thermal efficiency. Absorber topology, flow routing and materials contribute a significant portion towards thermal performance and overall thermal efficiency of collector and many research are being actively done in these areas. This review shall focus on the advances of topology designs, enhancement methods, thermal performance and absorber materials currently available for matrix type of solar air collector. Essential attributes influencing thermal performance of solar air collector with matrix absorber are also highlighted in this article

Design and performance of 20 watts portable solar generator

A new portable solar generator has been developed to generate electricity. It has the potential to replace petrol generator, widely used by peddlers at night markets (pasar malam). Conventional generators are heavy, oily, have high maintenance and use fossil fuel to generate electricity. The solar generator can generate 20 Watts of electricity. This amount of power can supply up to 96 hours of electricity for the purpose of lighting and running small electrical appliances. The power output is (alternating current) AC current using 150 Watts inverter with 200 Watts surge, suitable for all commercial single phase electric appliances. Solar charge controller is used to maximize the charging rate and to protect the battery. The system has low maintenance whereby the batteries need to be changed every three to four years, depending on the usage. The main concepts of portable solar generator are to reduce installation cost and to introduce a compact design of an optimal energy sizing system. The materials used to develop the solar generator can be easily obtained from local markets, thus reducing the cost of developing the system and making it suitable for commercialization

Evaluation of thresholding techniques on 3d fractal dimension MRI images

Currently, there are few textural measures being used to characterize the textual memorization of brain structures. Fractal Analysis (FA) application in medical field has been used to measure the occurrence of changes in the brain complexity for some diseased and normal aging brain. Within FA, there is Fractal Dimension (FD), which is an index of structural complexity. FD methods were classified into three major categories which are box-counting method, variance method and spectral method. Here in this study we used box-counting method to measure our FD due to its directness and automatic computability capabilities. We evaluated the impact of different thresholding techniques when quantifying the FD. We applied three different thresholding techniques on our brain MRI images: Otsu’s method, midpoint method, and hysteresis method. A total of 27 subjects (14 males and 13 females) aged ranging between 21-25 years old were voluntarily participated. The process of thresholding the images and computation of the FD values were done under MATLAB. There was a statistically significant difference between groups of thresholding techniques as determined by Friedman test with χ2(2)=48.667 and p-value was less than 0.001. Post-hoc Wilcoxon-Signed Ranked test with Bonferroni correction done where the p-value was set to 0.017. All three group pairs (midpoint vs Otsu’s, midpoint vs hysteresis and hysteresis vs Otsu’s) were statistically significant different with p-value less than 0.001. Pearson’s correlation showed moderate correlation (r=0.446, p-value = 0.02) between hysteresis and Otsu’s. Spearman correlation showed weak correlation which is not significant (r=0.256, p=0.198) for midpoint vs Otsu’s and (r=0.252, p=0.204) for midpoint vs hysteresis. In conclusion, different thresholding techniques do have impact on FD values, but with moderate correlation between them. Keywords: Box-counting; Thresholding; Fractal dimension; Brain; Magnetic resonance imaging; Textual memorizatio