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Thermoluminescence dosimetric characteristics of fabricated germanium (Ge) doped optical fibres for electron beams dosimetry: a preliminary study
No full textFlow velocity model for a coastal estuarine sandbar using multivariate regression
No full textFlow velocities through an estuarine sandbar under closed estuary condition for a temporary open/close estuary system (TOCE) corresponding to relation between river, groundwater and tidal levels were studied. Multivariate regression analysis was used to construct a model for estimating flow velocities. Validated model result shows a very good prediction for flow velocities in the sandbar (R2 = 0.9999). This simple approach could describe the effect of the transition phase (flow through a closed estuary) on channel flow and backwater behaviour in relation to tidal forcing into a sandbar. It implies a broader usefulness in channel flow routing in coastal areas with TOCE system for flood modelling and management purpose
Effects of microstructure architecture on the fracture of fibrous materials.
No full textFibrous materials is one of the potential scaffolds used for tissue engineered constructs. One of prerequisite properties for tissue engineered construct is fracture property. The work here study the relationship between microstructure architecture and fracture behavior of fibrous networks by using finite element analysis. The result shows that fibrous networks are toughened by either reducing the fiber density or cross-link percentage of networks. Such implementation increases the degree of non-affine deformation and produces a more compliant response at the crack-tip region. The nonaffine deformation in fibrous networks involves fiber movement like fiber rearrangement and reorientation, where such mechanisms allow stress delocalization to occur at the crack-tip region and results in a better fracture toughness of fibrous networks. The findings form this work provide the design guideline of fibrous materials with enhanced toughness for multiple applications
Numerical performance of AlGaN/GaN high electron mobility transistors under hydrostatic pressure and temperature.
No full textIn this paper, drain-source current, in AlGaN/GaN high electron mobility transistors have been investigated. In order to obtain parameters of exact AlGaN/GaN high electron mobility transistors such as electron density, the wave function, band gap, polarization charge, effective mass and dielectric constant, the hydrostatic pressure and temperature effects are taken into account. It has been found that the drain-source current decreases with increasing temperature and increases with increasing hydrostatic pressure. The increase in temperature is equivalent to a negative virtual gate and an increase in the hydrostatic pressure equivalent to the positive virtual gate voltage. Moreover, the temperature and hydrostatic pressure effective mass dependence in high electron mobility transistor structures are investigated, and it is observed that the increase of hydrostatic pressure decreases the effective mass and the wave function penetrated to quantum barrier AlGaN. The calculated results are in good agreement with existing experimental data
The potential of using Augmented Reality (AR) technology as learning material in TVET.
No full textIn the field of education today, people can choose from a variety of ways and methods to acquire specific information and skillshere are some good examples: classroom lectures with textbooks, computers, hand-held devices, and other electronics appliances such as tablets and smartphones. In a rapidly changing society, there are countless sources of knowledge and a great deal of available informationhence, adopting an appropriate method and applying relevant information at the right time and place are important in both schools and business settings. The augmented reality (AR) technology is one of the most advanced developments in the education sector tailored for 21st Century learning. With so much to offer, it is worthwhile to investigate the potential of integrating AR into the teaching-learning processes. This study focuses on exploring the possibility of merging TVET learning materials with the AR technolog
Optimization of headspace solid phase microextraction (HS-SPME) for the extraction of volatile organic compounds (VOCs) in MD2 pineapple
No full textSilver (I) Dicyanonitrosomethanide, Ag[ONC(CN)2] Complex as Catalyst for the Selective Oxidation of Styrene to Benzaldehyde
No full textSilver (I) dicyanonitrosomethanide, Ag[ONC(CN)2] represent a 3D interwoven coordination polymer organization in which all the donor atoms of the functional groups of ONC(CN)2- are coordinated to the Ag(I). Oxidation of styrene utilizing H2O2 as an oxidant in acetonitrile (CH3CN) was used as a model reaction to investigate the catalytic potential of the Ag (I) complex. The CH3CN was chosen as the solvent based on the data collected from Conductor like Screening Model for Real Solvents (COSMO-RS) study. The data indicate that the Ag [ONC(CN)2] complex was compatible and soluble in CH3CN. Different parameters such as styrene:H2O2 molar ratio, reaction time, catalyst mass, and reaction temperature were studied. Highest styrene conversion (36%) with 100% selectivity towards benzaldehyde (BZ) was achieved when 25 mg catalyst, 1:1 styrene to H2O2 molar ratio were used. The reaction was carried out at 303 K for 3 h. The catalytic conversion of styrene to BZ is proposed to take place via [Ag-H2O2] adduct with styrene oxide (StO) as an intermediate. Molecular Electrostatic Potential (MEP) shows that the Ag atom has the highest probability to coordinate with the oxygen atom of H2O2. The MEP data confirms the proposed mechanism