Search

The present study examined the level of outcome satisfaction of two main engineering courses taken by students in the Architectural Engineering department (AE) by evaluating the students' satisfaction result (SR), the attained level of the students' opinions (SO), and the instructors' opinions (IO). The AE program in United Arab Emirates University is one of the departments in the College of Engineering accredited by the Engineering Accreditation Commission of ABET which provides assurance that a College or University program meets the quality standards of the profession for which that program prepares graduates. The AE program offers a wide range of engineering courses at different levels from sophomore level to senior level. All the engineering courses are mainly prerequisites to the Capstone Engineering Design Project which builds on the outcomes of all courses to perform detailed design and cost estimates of the selected alternative solutions to a well-defined engineering problem. The two courses considered in this study are Building Electrical Circuits and Building Acoustics and Lighting. New assessment parameters which are the student course outcome satisfaction coefficient (SCOSC) and the mean absolute deviation around a central point (AMD) have been introduced in this paper. These two parameters are calculated based on the comparison of the students' satisfaction results with both students' opinions and insructors' opinions, and compare the mean absolute deviations of the students' direct results with the students' opinions and the instructors' opinions, respectively. Indeed, the course learning outcomes (CLOs) of the SR of some sections for both courses show higher attainment compared with the SO and IO.

This paper illustrates the impact of embedding an insulation layer of variable thermal conductivity in a typical building wall on the cooling effect and energy performance. The evaluation was performed by applying a conjugate heat transfer model, which was tested in extremely hot conditions of Al Ain (UAE). The thermal performance of a building incorporating insulation layers of variable thermal conductivity (k-value) was compared to a non-variable thermal conductivity system by quantifying the additional heat transferred due to the k-relationship with time. The results show that, when the k-value is a function of operating temperature, its effects on the temperature profile through the wall assembly during daytime is significant compared with that obtained when a constant k-value for the polystyrene (EPS) insulation is adopted. A similar trend in the evolution of temperatures during the day and across the wall section was observed when EPS material with different moisture content was evaluated. For the polyurethane insulation, the inner surface temperature reached 44 °C when constant k-value was adopted, increasing to 48.5 °C when the k-value was allowed to vary under the same ambient conditions.

The Ksar of Kenadsa counts among the most important old cities of the south-west region of Algeria by its cultural and religious dimension, its architectural value and the extent of its urban influence.Ksar has long been held as a functional and culturally radiant regional centre for all the western part of the Maghreb. this formerly powerful and influential centre is a shadow of its former self and today forms one peripheral district of a much larger city. The Ksar district is deserted by its occupants and subjected to the process of degradation. In this area, the traditional architecture evolved from an empirical knowledge, particularly oriented to the realisation of comfort in the hot season. The comfort requirements have changed, and so has the current architectural design. The city's development follows the example of the northern cities, which have a different climate. This raises questions concerning how the current architecture addresses local climate conditions characterised by a long and severe hot season. For this reason, the buildings must be designed according to the summer requirements. Winter conditions are less extreme so comfort conditions are easier to achieve. The comfort of the users was ensured in the past by a combination of several passive strategies of thermal control, which are the result of a thorough knowledge of the climatic conditions. To evaluate the thermal behaviour of this housing, a comparative analysis between the existing traditional and typical modern housing is carried out using TRNSYS software. The simulation results show that the typical modern house seems inappropriate for a desert climate. Indeed, except for the air- conditioning in summer there is no other solution that can ensure thermal comfort. For the two other traditional houses, in summer, are most effective in answering the heat problem for the two types of building materials tested (stone adobe, and hollow concrete block) . Keywords: Modern house, Temperature, Thermal comfort, Traditional house, TRNSYS, Introduction The new architecture produced during the last decades in Algeria, known as 'modern construction is completely non-adapted to climate and has high-energy consumption. This situation is attributed to a [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.solener.2005.06.002 Byline: Maatouk Khoukhi (a), Shigenao Maruyama (b) Keywords: Flat-plate solar collector; Glass cover; Optical constants; Non-gray; Semi-gray; Efficiency; Wind speed Abstract: A rigorous theoretical approach of a flat-plate solar collector with a black absorber considering the glass cover as an absorbing-emitting media is presented. The glass material is analyzed as a non-gray plane-parallel medium subjected to solar and thermal irradiations in one-dimensional case using the Radiation Element Method by Ray Emission Model (REM.sup.2). The optical constants of a clear glass window proposed by Rubin have been used. These optical constants, 160 values of real part n and imaginary part k of the complex refractive index of a clear glass, cover the range of interest for calculating the solar and thermal radiative transfer through the glass cover. The computational time for predicting the thermal behavior of solar collector was found to be prohibitively long for the non-gray calculation using 160 values of n and k. Therefore a suitable semi-gray model is proposed for rapid calculation. The profile of the efficiency curve obtained in the present study was found to be not linear in shape. Indeed, the heat loss from the collector is a combination of convection and radiation and highly non linear. The effect of the outside convective heat transfer on the efficiency curve is also studied. In fact, when the convection is the dominant heat transfer mode compared with the radiation one, the profile of the efficiency curve is more or less straight line. Consequently, the heat loss coefficient could be calculated using Klein model. It has been also shown that the effect of the wind speed on the glass cover mean temperature is very important. This effect increases with the increase of the mean absorber temperature. Author Affiliation: (a) Department of Architecture and Building Science, Graduate School of Engineering, Tohoku University, 6-6-11-1204, Aoba ku, Sendai 980-8579, Japan (b) Institute of Fluid Science, Tohoku University, Katahira, 2-1-1, Aoba ku, Sendai 980-8577, Japan Article History: Received 7 April 2004; Revised 1 June 2005; Accepted 7 June 2005 Article Note: (miscellaneous) Communicated by: Associate Editor Brian Norton

A rigorous approach for the radiative heat transfer analysis in solar collector glazing is developed. The model allows a more accurate prediction of thermal performance of a solar collector system. The glass material is analysed as a non-gray plane-parallel medium subjected to solar and thermal irradiations in the one-dimensional case using the Radiation Element Method by Ray Emission Model (REM by REM). This method is used to analyse the combined non-gray convective, conductive and radiative heat transfer in glass medium. The boundary surfaces of the glass are specular. The spectral dependence of the relevant radiation properties of glass (i.e. specular reflectivity, refraction angle and absorption coefficient) are taken into consideration. Both collimated and diffuse incident irradiation are applied at the boundary surfaces using the spectral solar model proposed by Bird and Riordan. The optical constants of a commercial ordinary clear glass material have been used. These optical constants (100 values) of real and imaginary parts of the complex refractive index of the glass material cover the range of interest for calculating the solar and thermal radiative heat transfer through the solar collector glass cover. The model allows the calculation of the steady-state heat flux and temperature distribution within the glass layer. The effect of both conduction and radiation in the heat transfer process is examined. It has been shown that the real and imaginary parts of the complex refractive index have a substantial effect on the layer temperature distribution. The computational time for predicting the combined heat transfer in such a system is very long for the non-gray case with 100 values of n and k. Therefore, a simplified non-gray model with 10 values of n and k and two semi-gray models have been proposed for rapid computations. A comparison of the proposed models with the reference non-gray case is presented. The result shows that 10 bandwidths could be used for rapid computation with a very high level of accuracy.

In 2013, UAE imported around 772 million kilograms of rice, making it one of the largest consumers of this popular grain in the world. However, 40% of rice available in the market is discarded, contributing to the country's CO2 footprint. Given that CO2 emissions are recognized as a significant contributor to climate change and efforts aimed at their reduction are proving insufficient for combatting the global increase in temperature, various approaches aimed at its removal from the atmosphere have been proposed. The goal of this study is to contribute to this initiative by proposing a new method for CO2 removal based on a special gas contact device filled with buffered puffed rice cakes obtained by heating in a purposely designed sealed chamber at high pressure to obtain layers with 9−12 mm thickness. The resulting cakes are subsequently immersed in a sodium hydroxide liquor (0.25−2.5 M) to increase the moisture content to 5% and pH to >11.0. In the experiments, different rice structures (stacked layers, rice grains, and multi-spaced layers) were tested, varying the CO2 percentage in the simulated effluent gas (1−15%). The highest CO2 uptake value (7.52 × 10−3 mole CO2/cm2 rice cake surface area) was achieved using 10% CO2 and a 500 mL/min flow rate with rice cakes of 80 mm diameter, comprising 12 mm thick layers that occupied 20% of the device volume. These results indicate that the proposed design exhibits high CO2 removal efficiency and should be further optimized in future investigations. [ABSTRACT FROM AUTHOR]