A Loss Analysis for a 28% Efficient 520X Concentrator Module
A module efficiency loss analysis has been conducted by comparing the efficiency of the module on-sun (28.2% peak) to the efficiency of the bare cell measured in the laboratory (35.5% peak). This analysis suggests that there are two main loss mechanisms in the module: elevated operating temperature and an optical efficiency less than unity. This analysis also suggests that the effects of spectral and intensity non-uniformity have been well controlled
III-V Solar Cells and Concentrator Arrays
Semiconductor heterostructures allow solving the problems of controlling the fundamental parameters of semiconductor devices owing to the possibility of change in the electronic band structure, bandgaps and refractive indices of a material itself during epitaxial growth, as well as effective masses and mobilities of charge carriers in it.
Cognitive Correlaretes of Physics Achievement of Some Nigeria Senior Secondary Students
Some cognitive correlates of physics achievement of some Nigeria senior secondary students were considered in the study. Specifically, the study examined the relationship between measures of student’s field independency. Cognitive tasks, formal reasoning and their achievement in physics. Purposive and stratified random sampling techniques were employed to obtain a sample of 524 senior secondary two students from six education zones in Kogi State of Nigeria. Three instruments were used. They are science Reasoning Tasks (SRTs). Group Embedded Figures Test (GEFT) and Physics Achievement Test (PAT). Data analysis using multiple regressions reveals that measures of students’ fields’ independency and cognitive tasks predicted student’s achievement in physics generally. However, only measure of field independency predicted students’ achievement in physics in the higher order cognitive demand questions. Measures of formal reasoning had no significant relationship with students’ achievements in physics generally or in higher order cognitive demand questions in physics. However, the overall relationships between measures of field independency, cognitive tasks, formal reasoning and students’ achievement in physics generally and in higher order cognitive demand questions in physics were both significant. Educational implications of these findings were discussed.