Ahmed Sherif

Excavation Game: Computer-Aided-Learning Tool for Teaching Construction Engineering Decision Making

This paper reports on an interactive computer-aided-learning (CAL) tool that was developed for the education of construction engineering students: the excavation game. It builds on the large potential of using CAL in education. CAL tools could offer a better learning environment for students, as they provide an excellent opportunity for applying and testing the management skills learned in classroom, but are difficult to implement in reality. In this research, the CAL tool focuses on improving students’ decision-making skills in the aspects of excavation and related activities. These are excavation equipment, dewatering, and soil-support methods. It also covers mobilization, surveying, safety, overtime shifts, and reporting. Students compete with regard to time, cost, and quality of construction of a given project. The game flow is nonlinear as it depends on students’ decisions. Wrong decisions deviate the construction flow to a path that costs money and time, while reducing quality. This must be correcte...

Daylighting Efficiency of External Perforated Solar Screens: Effect of Screen Axial Rotation under Clear Skies

This paper aims at developing solar screens for use in front of windows under the clear desert skies. These external perforated panels revitalize a traditional solution named “Mashrabeya”. They contribute to sustainability through utilization of natural light. In this paper, series of experiments were conducted using Radiance software. The impact of solar screen axial rotation on indoor daylighting of a residential setting was investigated. The effectiveness of the axial rotation was demonstrated. Screen influence on daylighting was strongly dependent on the orientation of the window and time. Illuminance adequacy was tested. The North and South orientations with upward and downward horizontal axial rotation were most affected when the rotation angle increased from 0° to 30°, especially in the summer season. In the East, the winter season was the most affected by the rotation. As a response to changing the rotation angle, a linear increase relationship was observed in all orientations.

Improving Buildings' Energy Performance by Defining Optimum Shape Geometry of Sun-Breakers Window Shading

Sun-breakers are commonly used as external shading devices in buildings. They are composed of protruding surfaces around window edges to block solar rays from entering into the spaces to reduce energy cooling loads Good design of sun-breakers blocks solar rays during hot summer months to reduce cooling load, while passes them during cold winter season to decrease heating load. However, this design method may be over-simplified for global use. There are many locations where winter solar access generates cooling loads. Also, months that are similar in solar path location -e.g. August and April- cannot be similarly treated, as their climatic thermal conditions are different. Current design methods may use geometrical analytic Approaches to design sun Breakers, others are based on energy saving, usually are search methods. This paper reports on a research that aims at enhancing current methods for defining the optimum shape geometry of sun breakers. By providing energy based cut-off date that can be used with geometrical methods for design of shading devices for each geographical location. Cut-off date is defined according to optimum annual energy performance, including heating and cooling, and lighting loads. The energy performance of a typical building space was modeled using Energy Plus software. Sun breaker edge profiles were defined to fit around this window by geometric modeling of the solar rays for monthly time periods. Annual energy performance of series of edge shapes was simulated. The optimum edge profiles and cut off months and hours were defined for different locations. Results demonstrate that the cut-off date depends on both Latitude and climatic Conditions, using the method can lead to the design of sun breakers with significant energy savings.

FINISH MATERIALS OF HOSPITAL OPERATING ROOMS OF THE USA AND EGYPT: SELECTION AND ACTUAL PERFORMANCE-IN-USE

The materials selected in finishing the surfaces of operating rooms can have an effect on performance. They must be suitable and supportive to the functions of these specialized spaces. Also, they must withstand the various demands resulting from the intensive use. This is especially important with the strict aseptic techniques that are typically observed in these spaces. This can also result in increased hospital operation and maintenance costs. This paper reports on the results of two surveys on the finish materials used in the floor, walls and ceiling surfaces of operating rooms. The study covered more than 546 operating rooms in more than 86 hospitals. The first survey was conducted for hospitals built –or renovated in the USA between 1980 and 2003. The second survey was conducted in Egypt for hospitals built, renovated, or under design between 2008 and 2012. The time difference between the two surveys was of little concern, since the performance of finish materials does not become apparent except after long term use that extends for years. The surveys identified the materials that were most commonly used in finishing the operating rooms in both countries. Also, views of the facility managers of the USA hospitals in regards to the actual performance of these materials were collected. These were compared with previous studies in Egypt and the USA. The paper draws useful conclusions to architects, administrators and facility managers on the most popular finish materials used in these specialized spaces. Also, views of the facility managers on the performance-in-use of these materials were identified. This included performance of the most popular materials in regards to their sterile properties, durability, maintenance, aesthetics, comfort, safety and cost.

Energy Efficiency of External Perforated Window Solar Screens in Desert Environments: Effect of Screen Surface Reflectance

In hot-arid desert environments, solar radiation passing through windows increases buildings energy consumption. Shading of windows can reduce these loads. Previous research proved that external deep perforated solar screens can achieve up to 30% energy savings. Solar screen colors should be taken into consideration as the lighter the color, the more transmitted proportion of radiation due to increased reflectance, hence affecting daylighting and buildings thermal performance. This paper investigated the influence of surface reflectance on the energy saving capacity of solar screens in the hot arid desert environment. The relation between screen surface reflectance and other configuration parameters was examined. Series of experiments were performed using the EnergyPlus simulation software for a range of solar screen colors ranging from white screens having a visible reflectance of one, to black screens with a visible reflectance of zero. Simulations were conducted for a screen fixed in front of a window of a typical residential living room space in the Kharga Oasis, located in the Egyptian desert. It was found that light colored screens reduce lighting and heating energy. However, they significantly increase the cooling energy, and thus overall energy consumption. Results scientifically confirm the effectiveness of the traditionally used colors of the old Mashrabeya solar screens, which were typically dark. Conclusions prove that screens visible reflectance could reduce energy savings up to 14%. Optimum ranges of screen visible reflectance were recommended.