4,516 research outputs found
Numerical study of a hybrid photovoltaic thermal desalination system
The world as we know it depends highly on fossil fuels. However, these resources are finite, and evidence suggests that their combustion contributes to climate change. In addition, fresh water supplies are becoming scarcer amidst instabilities in weather patterns and unsustainable water consumption levels. As such, photovoltaic (PV) systems have emerged as a potential off-grid alternative to traditional fossil fuel energy generation. However, their widespread proliferation is, in part, inhibited by their inefficiency as less than 20% of incident solar energy is converted to electrical energy. Hybrid photovoltaic thermal (PV/T) desalination systems have emerged as one way of improving the overall efficiency of PV panels as they make use of the waste heat from panels to aid the desalination process in solar stills. Solar stills have been modelled with software for the purpose of performance optimisation, but most of them do not account for the still's view factor in the calculation of internal radiative heat transfer coefficient. The aim of this study was to construct a numerical model for a hybrid PV/T desalination system and determine its accuracy. The modelling was undertaken in Matlab and was validated against experimental data from a previous study using Root Mean Square Error (RMSE) and correlation values. It was observed that the model performed adequately as a water yield RMSE value of 22.0% was found. Furthermore, it was found that the view factor reduces the RMSE of hourly water yield from 28.9% to 22.0% and improves the correlation factor from 0.9890 to 0.9896. Sensitivity analyses were performed with annual data from Stellenbosch, South Africa (33.935°S 18.7817°W) and indicated an optimal water depth of 0.02m for high water yield, and 0.04m for high electrical energy yield. Also, an optimal panel tilt angle of 30° was found for both water and electrical energy yields and optimal cover tilt angles of 40° and 60° were observed for maximum water and electrical yields respectively. The conclusion of this study was that the incorporation of a view factors does indeed improve the accuracy of hybrid PV/T desalination system models. Additionally, low basin water depth is favourable for high water yields and high basin water depth, for high electrical energy yields. Furthermore, a panel tilt angle of 30° is optimum for both types of yield. Finally, the still cover tilt angle should be set to 40° for optimal water yields, but should be as steep as possible for optimal electrical energy yields
E-Proxies for Sale? Corporate Vote-Buying in the Internet Age
Advances in electronic communications technology promise to invigorate shareholder voting as a viable tool for corporate governance, for example by decreasing the cost, and thereby increasing the frequency and effectiveness, of proxy fights. Increased use of shareholder voting, though, forces renewed focus on issues related to the shareholder voting process. One such issue is vote-buying. Traditionally, courts have treated vote-buying in the corporate context as per se illegal. More recently, however, courts have relaxed their attitude toward such transactions, a move generally applauded by commentators. This article argues that the newfound judicial acceptance of vote-buying is problematic, at least for publicly-held corporations. The article examines the reasons offered in support of vote-buying in such corporations, and suggests that the same benefits could be obtained, without the threat of harm presented by vote-buying, through the use of turnout payments to encourage shareholder participation in corporate voting contests. With regard to closely-held corporations, however, the article argues that vote-buying serves a useful preference aggregation function and generally should be permitte
Counsel Fees in Stockholders\u27 Derivative and Class Actions-Hornstein Revisited
In 1939, the first in a series of four comprehensive law review articles by Professor George D. Hornstein was published on the subject of the award of counsel fees in stockholders\u27 derivative suits and corporate class actions. These articles highlighted equitable principles peculiar to such actions, previously not fully understood by either attorneys or the courts, which have made derivative and class actions extremely effective weapons in the battle for corporate democracy. Three very basic questions were posed and answered: 1) Who will pay for the attorneys fees and expenses incurred in such litigation? 2) What factors govern the award of counsel fees? 3) How are they calculated
Engaging fathers : examining social service agency father-friendliness and its relationships with father involvement
Social scientists have become increasingly interested over the past 30 years in the role fathers play in child development. As a result, a large bank of research has been accumulated; however, one area in this literature which remains understudied is the relationships between agency father friendliness and father involvement. This paper is one attempt to understand the intricacies of the interchange point between fathers and agencies by using longitudinal data collected by the Supporting Father Involvement study, specifically examining the associations between father involvement and father friendliness, as well as the relationships among the various components of agency father friendliness over time. Based on the results of the analysis, recommendations are made about how agencies can increase their level of father friendliness and increase father involvement among their clients
Faculty Recital: Douglas Lindsey, trumpet
KSU School of Music presents Douglas Lindsey, trumpet.https://digitalcommons.kennesaw.edu/musicprograms/1297/thumbnail.jp
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