Facades Solar Screens Impact on Daylighting Performance in Buildings

Cities in hot climates feature clear skies most of the year, guarantting the provision of daylight into the interior. With the use of large glazed façades, controlling the penetration of solar radiation that contributes to thermal discomfort with passive solutions is acheived through the use of shading devices.These devices decrease energy loads of mechanical cooling. The facade solar screens is one of the shading strategies used and reported to be succeful in such hot climatic regions, blocking solar radiation while allowing visual access to external views. Such a strategy of screening the opennings with perforated surfaces has cultural and historical significance in multiple urban environmnets, demonstrated by the use of the traditional mashrabeya which are the inspiration for contemporary screens design. However, throughout the last decade, a large body of research has been concerned with the negative impact of solar screens on daylighting performance in internal spaces, leading to an increase in energy loads of artifical lighting. This paper aims to review the current research body concerned with the correlation between solar screens design parameters and daylighting performance. 21 articles fall under this paper’s realm. They are reviewed according to multiple comparison points, including: aims, spatial configuration of the test spaces, types and design of the tested solar screens, design parameters tackled, daylighting simulation tools, daylighting metrics, and finally, findings including parameters impact, empirical process methodolgy, and coorelation with other enviromental aspects. Thispaper discusses how the curent reviewed research body informs the design process for an environmentally conscious design of optimized solar screens with respect to daylight availability thereby promoting the use of passive design strategies towards greener cities and urban environments

Effect of Scan Body Design on the Accuracy of the Implant Position in Implant Supported Prosthesis

Background: Several treatment options are planned for completely edentulous patients rehabilitation which were developed to meet patients desires and requirements, starting from conventional complete denture till implant supported fixed full arch cases. Each technique has its own indication and limitations. Passive fit is an important factor for the long-term success of implant- prosthesis, which necessitate accurate transfer of the implant position. Recently, digital impressions have been introduced in dental implant treatment. By the use of scan body and different optical scanning methods, the position of scan bodies can be transferred to a virtual implant position within the dental arch. Material and Methods: a standardized model was used to evaluate trueness, precision and overall accuracy between two types of scan body. The first is a scannable healing abutment. and a second a scannable healing abutment modified by adding plastic cap. A scan was made to four standard long scan bodies, and it was considered a base line of measurement (control group) control baseline. Results: The results showed that there was a statistically significance difference when comparing trueness between scannable healing abutment and healing abutment with plastic cap on both occlusal and mid axial direction with a P-value 0.000* and 0.003* respectively. Conclusion: Within limitations of this study it could be concluded that using scannable healing abutment with plastic cap had better accuracy than scannable healing abutment without plastic cap