Several studies on photovoltaic systems focused on how it operates and energy required in operating it. Little attention is paid on its configurations, modeling of mean time to system failure, availability, cost benefit and comparisons of parallel and series–parallel designs. In this research work, four system configurations were studied. Configuration I consists of two sub-components arranged ...

Information provenance is a mechanism for tracing and verifying sources of information. In software development, provenance can be seen in two dimensions: (a) traceability among different versions of the same artifact and (b) traceability among various artifacts across system lifecycle. Maintaining the provenance, including the history of changes and the rationale of changes, are critical in as...

The purpose of this study was to determine the effects of a particular psychological stress, exposure to an open-field, on plasma IL-6 activity in rats. Plasma IL-6 activity was 40.6 +/- 7.2 units/ml in control rats, 105 +/- 6.8 units/ml after 30 minutes exposure to an open-field, and 221 +/- 17 units/ml after 60 minutes of exposure (p = 0.0003). There was a positive correlation (r = .71, p = 0...

OBJECTIVES Many analytical methods are not very sensitive to change because of the difficulty of distinguishing short-term fluctuation from the developmental change of primary interest. The current project investigated one possible solution to this problem in the form of a measurement-burst design in which research participants perform several versions of each test at each measurement occasion....

General lifestyle activities were examined as a predictor of current cognition and cognitive change over a 6-year interval in older adults. Participants were drawn from a population-based longitudinal study, and they completed the Adelaide Activities Profile and a battery of tests measuring cognition and sensory functioning. Hierarchical regression analyses revealed that, after sensory function...

A moisture- electrical - temperature (MET) test is proposed to evaluate the outdoor reliability of high power blue LEDs, with and without phosphor, and to understand the degradation physics of LEDs under the environment of combined humidity, temperature and electrical stresses. The blue LEDs with phosphor will be the high power white LEDs. Scanning acoustic microscopy is used to examine the res...

It has been suggested that work characteristics, such as mental demands, job control, and occupational complexity, are prospectively related to cognitive function. However, current evidence on links between psychosocial working conditions and cognitive change over time is inconsistent. In this study, we applied the effort-reward imbalance model that allows to build on previous research on menta...

It is proposed that personality (conceptualized in terms of motives and psychological resources) changes normatively not only from young adulthood to middle age but also within middle age and that these changes take place in relation to social and biosocial change over the same period. Data from 123 women studied at ages 27, 43, 52, and 61 largely supported hypotheses about change in social rol...

BACKGROUND A Vygotskian framework links cognitive change to collaborative interaction with a more competent partner whereas a Piagetian perspective supports the view that cognitive conflict arising from peer interaction leads to cognitive change. AIMS The study investigated the effect of collaborative learning on children's problem-solving ability and whether differences in knowledge status o...

Research on age-related cognitive change traditionally focuses on either development or aging, where development ends with adulthood and aging begins around 55 years. This approach ignores age-related changes during the 35 years in-between, implying that this period is uninformative. Here we investigated face recognition as an ability that may mature late relative to other abilities. Using data...