Chosen diagnostic methods of photovoltaic modules
Solar modules under ordinary working condition are exposed to amount of degradation factors which deteriorate their properties. The most important degradation of PV modules during operation are optical, electrical and thermal degradation. The result of these factors is performance degradation of the modules, or even can caused their fault. It is important to find the cause of the fault and its timely removal. The choice of convenient diagnostic method can reduce financial losses and increases safety of photovoltaic power plant. The example of tests performed on PV modules by using infrared (IR) thermography and, potential induced degradation (PID) are presented in this paper.
Faults in photovoltaic modules and possibilities for their detection by thermographic studies
This paper presents a review of the studies of photovoltaic modules through passive thermography. The different types of faults in photovoltaic panels and their representation in the thermographic images are considered. The factors that influence the study and the ways to avoid them are described.
Drug Testing in Public Agencies: Are Personnel Directors Doing Things Right?
The results of a survey of 300 public agencies personnel directors are reported. The report describes the drug and alcohol testing policies and procedures now used by these respondents. The implications of the survey results are evaluated in terms of critical issues of personnel management practice and public policy: (1) the protection of employees' constitutional rights, (2) the public's right to an effective public service, and (3) management's need to reduce liability risks and to increase program effectiveness.