Development Of Optical Fiber Vis-Nir Spectroscopy System For Metrological Analysis On Intrinsic Qualities Of Averrhoa Carambola L

Optical measuring techniques are one of the methods that have shown promising results in non-destructive quality evaluation. In this research, several approach in quantifying fruits intrinsic quality have been successfully performed through absorbance, reflectance and interactance techniques via visible and near infrared spectral as well as novel application of monochromatic measurement systems. The research begins by Aquaphotomics assessment (NIR absorbance) of water-sugars (sucrose, glucose and fructose) and water-acids (citric, tartaric, malic and oxalic) solutions which are common biochemical composition in fruits

Reflections and Future Directions for the Green Maritime Supply Chain in Malaysia

The maritime sector and shipping industry have been argued to be effective drivers of international trade. Internationalization has become a strategic business plan by entrepreneurs and industry players to expand the business, especially when their business was already established in the domestic market. However, current international laws began to be tightened by requiring each exporting and shipping firms to implement green sea transport practices and documentations. A limited number of empirical-based evidence has forced the maritime practitioners to conduct business without clear green concepts knowledge and availability of best business practices to be benchmarked. With this in mind, the aim of this chapter is to examine current issues, differences, and dilemmas confronting practitioners, governments, stakeholders, and scholars. This chapter has developed a green maritime supply chain concept based on practitioners' reflections and provides future direction to scholars interested in studying green logistics and supplying chain management in the maritime sector

Magnus wind turbine: the effect of sandpaper surface roughness on cylinder blades

The Magnus wind turbine is an invention that uses rotating cylinders as blades to extract energy fromthe wind. This invention overcomes the limitation of operating a wind turbine at low wind speed conditions.However, research regarding the torque generated by enhancing the surface roughness of the Magnus windturbine is still lacking. Thus, the study aims to understand the effect of varied sandpaper surface roughnesses onthe Magnus wind turbine torque output. The approaches used are: experimentation using a 6 cylinders modelinside a wind tunnel for Magnus force comparison, a Magnus wind turbine model for torque performance andsmoke flow visualisation for boundary layer analysis. The results show that the torque coefficient producedby P40 sandpaper to smooth the surface roughness is 0.079–0.016, which is nearly a five times improvementin the torque coefficient. On the other hand, the tip speed ratio further increases from smooth to rough surfaceenhancement (0.057–0.147). This significant finding indicates that the Magnus wind turbine performance canbe further improved using sandpaper surface roughness

VIS-NIR spectral and particles distribution of Au, Ag, Cu, Al and Ni nanoparticles synthesized in distilled water using laser ablation

In this research, gold (Au), silver (Ag), copper (Cu), aluminium (Al) and nickel (Ni) nanoparticles have been prepared by laser ablation in distilled water using Q-switched Nd: YAG. Comparative analysis between 1064 nm and 532 nm laser wavelength in term of absorption spectra and particle size distribution is performed. The synthesized nanoparticles were characterized by visible (VIS) and near infrared (NIR) spectrometer and transmission electron microscopy (TEM). The effect of laser pulse energy and laser wavelength on the size distribution and absorbance spectrum of metal nanoparticles was studied. The absorption peak intensities of the nanoparticles increase at higher laser pulse energy. It is discovered that for all metals, 532 nm laser produced nanoparticles with higher absorption peak intensities than 1064 nm. The work also shows that there is no noticeable difference in the size of the nanoparticles produced at 532 and 1064 nm for the Ni and Cu metals. However, a considerable size difference can be seen for Au, Ag, and Al at the two laser wavelengths. Smaller Ag nanoparticles were produced by 1064 nm laser while smaller Au and Al nanoparticles were produced by 532 nm laser

An experimental investigation on the effect of surface roughness on the performance of Magnus wind turbine

Wind turbine that used airfoil-shaped blades cannot harvest wind energy at low speed wind condition efficiently. A wind turbine that used Magnus effect is proposed to overcome the wind speed problem. Magnus wind turbine (MWT) performance can be further enhanced by using sanded surface on the rotating cylinder blades but the surface roughness effect on MWT are not yet fully explored. Experimental approach by wind tunnel is conducted in order to understand the effect of surface roughness. Blades rotation speed and wind speed are the controlled variables. Meanwhile, torque, torque coefficient and tip speed ratio are the measured variables. The experiment shows that sanded surface roughness can significantly increase the MWT performance up to four times based on torque production in comparison with the smooth surface. In conclusion, the results proved that surface roughness can be used to improve MWT

Torque performance study of magnus wind turbine

Current wind turbine technology cannot operate in low wind velocity conditions to produce adequate torque for high capacity generators. This Magnus Wind Turbine (MWT) experiment aims to study the torque performance in relationship with the frequency of rotation of the cylinder blade. The experiment started with the design and fabrication of the MWT through computational calculation and simulation. This study solves the relationship gap between the torque generated and the rotation frequency of the cylinder blade by building upon previous research where only one type of rotation frequency of the cylinder blade was used. The research is done inside a wind tunnel by attaching a spring balance to the rotor shaft through a rope. The spring balance stops the rotor shaft from rotating at certain positions and the corresponding torques were measured, while the rotation frequency of the cylinder blade and wind velocity are controlled. The results show a positive trend that the torque generated will increases as rotation frequency of the cylinder blade and wind velocity are increased. Therefore, the results indicate the possibility that a higher torque can be produced by MWT in countries with low wind velocity

Computational approach in sizing of pulsejet engine

Research in pulsejet has intensified recently due to its design simplicity that can be developed into efficient small scale propulsive units for new applications such as UAVs and Unmanned Combat Vehicles (UCAV). A major obstacle for its development is low efficiency of the engine. The objective of this research is to investigate the possibility of using pulsejet in certain applications where the pulsejet can trade its low efficiency with low cost, simple design, and light weight. Numerical analysis is used for analysing the pulsejet engine design. The main results drawn from this research is in increasing efficiency and improving performance of engine by improving size of engine, especially diameter of combustion chamber. The computed results show good resemblance with published data

Brain-derived neurotrophic factor (BDNF) in schizophrenia research: a quantitative review and future directions

This review aims to perform a bibliometric analysis of the research related to brain-derived neurotrophic factor (BDNF) in schizophrenia and offer suggestions for further work. Based on the keywords used, our study retrieved 335 documents for further analysis using a combination of three bibliometric techniques: co-word analysis, document co-citation analysis, and bibliographic coupling. A general rising trend in the number of publications was found in BDNF and schizophrenia research. Researchers from China and the United States have mostly researched BDNF and schizophrenia. Molecular Psychiatry is the most prestigious journal in the field of BDNF and schizophrenia research. The main topics and important research areas are cognition and the involvement of BDNF as a neurobiological marker (pathogenesis, therapy monitoring, and risk factors). Future research is anticipated to concentrate on relevant subjects, such as factors that affect BDNF levels or are connected to BDNF dysfunction in schizophrenia, as well as animal models of schizophrenia, in addition to cognition in schizophrenia