Numerical analysis of natural convection in shed roofs with eave of buildings for cold climates

A numerical study has been carried out on partially heated triangular enclosures with eave. The eave and inclined wall has a cold temperature. The laminar, two-dimensional, steady governing equations of natural convection are solved in the streamfunction-vorticity form using a finite difference technique. Streamline, isotherm and Nusselt number are presented for different parameters such as aspect ratio AR=H/L from 0.25 to 1, ratio of eave length E=L/n where n changes from 3 to 7 and Rayleigh number from 10³ to 10⁶. It is observed that the heat transfer decreases with increasing aspect ratio for small Rayleigh number but increases for higher Rayleigh number. Heat transfer also increases with decreasing eave length.     

Magnetohydrodynamic natural convection in trapezoidal cavities

A computational numerical work has been done to see the effects of magnetic field on natural convection for a trapezoidal enclosure. Both inclined walls and bottom wall have constant temperature where the bottom wall temperature is higher than the inclined walls. Top wall of the cavity is adiabatic. To investigate the effects, finite element method is used to solve the governing equations for different parameters such as Rayleigh number, Hartmann number and inclination angle of inclined wall of the enclosure. It is found that heat transfer decreased by 20.70% and 16.15% as φ increases from 0 to 60 at Ra = 10⁵ and 10⁶ respectively. On the other hand, heat transfer decreased by 20.28% and 13.42% as Ha increases from 0 to 50 for Ra = 10⁵ and 10⁶ respectively.     

Situational Privacy Concerns and Antecedent Factors

This study examines the factors that contribute to context-based, or situational, privacy concerns drawing upon the theoretic lens of attribution theory. We posit that situational privacy concerns develop through individuals’ causal explanations of prior privacy incidents in addition to their trait-like, or dispositional, privacy concerns. Analysis of data from 156 participants confirms the significance of the relationships between a number of antecedent constructs and situational privacy concerns. The hypotheses developed to test these relationships were all supported through partial least squares, as were the psychometric properties of the scales used. The results further our understanding of context-based privacy concerns, particularly the mechanics of attribution in blaming, and holding online service providers responsible for privacy transgressions. Insights into situational privacy concerns help online service providers handle and ameliorate these concerns.     

Estimation of solar radiation using artificial neural networks with different input parameters for Mediterranean region of Anatolia in Turkey

An artificial neural network (ANN) model was used to estimate the solar radiation parameters for seven cities from Mediterranean region of Anatolia in Turkey. As well known that Turkey is a bridge between Asia and Europe and it lies in a sunny belt, between 36° and 42°N latitudes. Indeed, the country has sufficient solar radiation intensities for solar applications. In order to make estimation of solar radiation, the data from the Turkish State and Meteorological Service were used. Data of 2006 were used for testing and data of 2005, 2007, and 2008 were estimated. Effects of number of input parameters were tested on solar radiation that was output layer. With this aim, number of input layer parameters changed from 2 to 6. The obtained results indicated that the method could be used by researchers or scientists to design high efficiency solar devices. It was also found that number of input parameters was the most effective parameter on estimation of future data on solar radiation.