22 research outputs found
A preliminary factor analytic investigation into the first-order factor structure of the Fifteen Factor Plus (15FQ+) on a sample of Black South African managers
The original publication is available at http://www.sajip.co.zaMoyo, S. & Theron, C. 2011. A preliminary factor analytic investigation into the first-order factor structure of the Fifteen Factor Plus (15FQ+) on a sample of Black South African managers. SA Journal of Industrial Psychology, 37(1), 1-22, doi: 10.4102/sajip.v37i1.934.Orientation: The Fifteen Factor Questionnaire Plus (15FQ+) is a prominent personality
questionnaire that organisations frequently use in personnel selection in South Africa.
Research purpose: The primary objective of this study was to undertake a factor analytic
investigation of the first-order factor structure of the 15FQ+.
Motivation for the study: The construct validity of the 15FQ+, as a measure of personality, is
necessary even though it is insufficient to justify its use in personnel selection.
Research design, approach and method: The researchers evaluated the fit of the measurement
model, which the structure and scoring key of the 15FQ+ implies, in a quantitative study that
used an ex post facto correlation design through structural equation modelling. They conducted
a secondary data analysis. They selected a sample of 241 Black South African managers from
a large 15FQ+ database.
Main findings: The researchers found good measurement model fit. The measurement model
parameter estimates were worrying. The magnitude of the estimated model parameters
suggests that the items generally do not reflect the latent personality dimensions the designers
intended them to with a great degree of precision. The items are reasonably noisy measures of
the latent variables they represent.
Practical/managerial implications: Organisations should use the 15FQ+ carefully on Black
South African managers until further local research evidence becomes available.
Contribution/value-add: The study is a catalyst to trigger the necessary additional research
we need to establish convincingly the psychometric credentials of the 15FQ+ as a valuable
assessment tool in South Africa.Publisher's versio
Computer Modeling the Excitonic Reflection and Photoluminescence Spectra of GaN Epitaxial Layers
Photoluminescence (PL) and reflection excitonic spectra o f GaN single layer grown on sapphire substrate by MOVPE were modeled with aim to estimate a basie parameters o f free A- and B- excitons. The calculations were performed in the frame o f two-oscillator model for dielectric function e(E). Three layered model o f crystal was used for fitting o f reflection spectrum which was measured at T=80K. In this way the dead layer thickness d=6 nm, resonance energies Eа=3.4916 eV and Eв = 3.5008 eV as well as the broadening parameters Га = 5.27 meV and Гв = 7.14 meV of the free excitons were obtained. These parameters were used then for fitting of PL spectra in assumption o f the thermal equilibrium for excitons taking into account the self-absorption of resonance emission. The values of diffusion coefficients Dа =0.3 cm²/s, Dв = 0.1 cm²/s and exciton lifetimes Ƭa = 37 ps, Ƭв = 17 ps were estimated
Иммобилизация РАО в перовскитоподобную матрицу
Выпускная квалификационная работа с., рис., табл., источников, прил.
Ключевые слова: перовскит, иммобилизация радиоактивных отходов, самораспространяющийся высокотемпературный синтез, матричные материалы
Объектом исследования является иммобилизация радиоактивных отходов в матричный материал методом СВС на основе перовскита.
Цель работы – получение химически устойчивой матрицы для иммобилизации актиноидной фракции радиоактивных отходов методом СВС
В процессе выполнения магистерской диссертации отработана технология получения матричного материала методом СВС. В результате исследования были определены закономерности образования фаз состава матриц.
Степень внедрения: организация технологического процесса иммобилизации актиноидной фракции радиоактивных отходов методом СВС
Область применения: атFinal qualifying work with., Fig., Tab., Sources, adj.
Keywords: perovskite, radioactive waste immobilization, self-propagating high-temperature synthesis, matrix materials
The object of research is the immobilization of radioactive waste in the matrix material by the SHS-based perovskite.
The purpose of work - to obtain a chemically stable matrix for the immobilization of actinide fraction of radioactive waste by SHS
In carrying out the master's thesis the technology of producing the matrix material by SHS. The study of the formation of the composition of the matrix phase have been identified.
Degree of implementation: the organization of the process of immobilization actinide fraction of radioactive waste by SHS
Scope: the nuclear industry
Modeling AlGaN p-i-n photodiodes
Ternary AlGaN alloys with a band gap of 3.4 to 6.2 eV are very promising for photodetectors in the UV wavelength range. Using the COMSOL MULTIPHYSICS software based on AlGaN, a p-i-n photodiode model was developed, including its I–V characteristic, spectral sensitivity of the received radiation, absorption coefficient as a function of the aluminum fraction and the depletion layer thickness. To calculate the process of interaction of a semiconductor with EM radiation, we used a model based on the use of an element of the transition matrix through the carrier lifetime during spontaneous recombination. In this case, the peak sensitivity of the photodiode is from 0.08 to 0.18 A/W at wavelengths of 0.2–0.33 µm. This is in line with experimental results taken from the relevant literature.Ternary AlGaN alloys with a band gap of 3.4 to 6.2 eV are very promising for photodetectors in the UV wavelength range. Using the COMSOL MULTIPHYSICS software based on AlGaN, a p-i-n photodiode model was developed, including its I–V characteristic, spectral sensitivity of the received radiation, absorption coefficient as a function of the aluminum fraction and the depletion layer thickness. To calculate the process of interaction of a semiconductor with EM radiation, we used a model based on the use of an element of the transition matrix through the carrier lifetime during spontaneous recombination. In this case, the peak sensitivity of the photodiode is from 0.08 to 0.18 A/W at wavelengths of 0.2–0.33 µm. This is in line with experimental results taken from the relevant literature
Modeling AlGaN p-i-n photodiodes
Ternary AlGaN alloys with a band gap of 3.4 to 6.2 eV are very promising for photodetectors in the UV wavelength range. Using the COMSOL MULTIPHYSICS software based on AlGaN, a p-i-n photodiode model was developed, including its I–V characteristic, spectral sensitivity of the received radiation, absorption coefficient as a function of the aluminum fraction and the depletion layer thickness. To calculate the process of interaction of a semiconductor with EM radiation, we used a model based on the use of an element of the transition matrix through the carrier lifetime during spontaneous recombination. In this case, the peak sensitivity of the photodiode is from 0.08 to 0.18 A/W at wavelengths of 0.2–0.33 µm. This is in line with experimental results taken from the relevant literature
Modeling AlGaN p-i-n photodiodes
Until recently the main technique for modeling physical processes was to compose equations that would
describe the processes and solve them with some math package, like in. But today’s expert systems for modeling different processes are not worse than “manual” modeling. At the same time they provide a rich apparatus to program equations and present their results. This report considers using COMSOL MULTIPHYSICS software to create a model of a p-i-n photodiode based on AlGaN alloy