The Role of Interpretive Evaluation in Engineering Information Systems Requirements

The requirements for complex systems inevitably change continuously. Any successful software or information systems engineering approach needs to observe this simple fact. This paper argues for the critical importance of formative evaluation activities in any non-sequential, or learning-based RE process. We argue that evaluation with its focus on understanding and interpreting the evaluation results, is distinct from measurement. We also outline how evaluation activities can be performed from an interpretivist perspective, in a way that systematically informs formative evaluation activities during gradual, experimental requirements engineering activities

Design Wind Loads Including Torsion for Rectangular Buildings with Horizontal Aspect Ratio of 1.6

Limited information is available regarding wind-induced torsional loads on buildings. This paper presents results of tests carried out in a boundary-layer wind tunnel using building models with the same plan dimensions (aspect ratio of 1.6) and located in a simulated open terrain exposure for different wind directions. Synchronized wind pressure measurements allowed estimating instantaneous base-shear forces and torsional moments on the tested rigid building models. Results were normalized and presented in terms of shear and torsional coefficients for two load cases, namely: maximum torsion and corresponding shear, and maximum shear and corresponding torsion. Comparison of the wind-tunnel test results with current torsion- and shear-related provisions in the American standard demonstrates good agreement for low-rise buildings but differences for medium-rise buildings

Double-diffusive natural convection with Soret/Dufour effects and energy optimization of Nano-Encapsulated Phase Change Material in a novel form of a wavy-walled I-shaped domain

Background: As building segment grows in parallel with amplifying population, the necessity for consumption of energy needed to passive and active heating or cooling buildings for thermal comfort increases. Schemes such as developing green buildings for sustainable architecture were utilized to address this issue. The utilization of Phase Change Materials (PCMs) with the aim of active and passive cooling or heating of buildings illustrates a promising and modern technique. Methods: This study's objective is to perform a numerical analysis using the finite element method, FEM for modeling free convection produced by double-diffusion (DDNC) with Soret/Dufour effects of Nano-Encapsulated PCMs within an I-shaped enclosure equipped with a novel type of corrugated vertical walls subjected to Neumann thermal and solutal conditions. Findings: Results are interpreted and assessed in relation to the governing factors, such as buoyancy ratio (N), Rayleigh and Lewis numbers (Ra, Le), the height of corrugated walls (a), Stefan number (Ste), non-dimensional fusion temperature (θf), Dufour (Df), and Soret (Sr) parameters. High values of N and Ra, and low values of Le and a, caused in the highest rate of heat and mass exchange. The irreversibilities due to the heat and mass transfer effects increase as the flow intensity within the system decrease. Decreasing the latent heat of the NEPCM cores and increasing their fusion temperature lowering the heat transfer rates, while improving mass transfer rates. This configuration can help in the design of the storage tank in hydronic apparatus for cooling, heating, and domestic hot water in buildings

Comparison of Wind Tunnel Measurements with NBCC 2010 Wind-Induced Torsion Provisions for Low- and Medium-Rise Buildings

The aim of this study is to assess wind-induced torsional loads on low- and medium-rise buildings determined in accordance with the National Building Code of Canada (NBCC 2010). Two building models with the same horizontal dimensions but different gabled-roof angles (0° and 45°) were tested at different full-scale equivalent eave heights (6, 12, 20, 30, 40, 50, and 60 m) in open terrain exposure for several wind directions (every 15°). Wind-induced measured pressures were numerically integrated over all building surfaces and results were obtained for along-wind force, across-wind force, and torsional moment. Torsion load case (i.e., maximum torsion and corresponding shear) and shear load case (i.e., maximum shear and corresponding torsion) were evaluated to reflect the maximum actual wind load effects in the two horizontal directions (i.e., transverse and longitudinal). The evaluated torsion and shear load cases were also compared with the current torsion- and shear-related provisions in the NBCC 2010. The results demonstrated significant discrepancies between NBCC 2010 and the wind tunnel measurements regarding the evaluation of torsional wind loads on low- and medium-rise buildings. Finally, shear and torsion load cases were suggested for evaluating wind loads in the design of low- and medium-rise rectangular buildings

Wind-induced Torsional Loads on Low Buildings

Wind-induced instantaneous pressures on low building envelopes continuously vary in temporal and spatial dimensions and this may lead to significant torsional moments on the building's lateral load resisting system. Studies on wind-induced torsional loads on low buildings are very limited. Wind-induced torsion provisions in the American Society of Civil Engineers Standard (ASCE/SEI 7-10, 2010), the National Building Code of Canada (NBCC, 2010), and the European Code (EN 1991-1-4, 2005) were reviewed and compared for three gabled-roof (18.4°) low buildings. Significant discrepancies were found among the provisions of these wind standards in evaluating torsional wind loads on low buildings. In addition, wind-induced torsional loads on low buildings have been measured in a boundary layer wind tunnel. Three low buildings, with the same plan dimensions but different gabled-roof angles (0°, 18.4°, 45°) and two different heights (i.e. full, and half eave building height) were tested in simulated open and urban terrain exposures for different wind directions (from 0° to 180° every 15°). The experimental results were compared with current wind-induced torsional load provisions. It was found that NBCC (2010) underestimates the torsional moments on low buildings significantly

Synthesis, structural and morphological characterizations of nano-Ru-based perovskites/RGO composites

Highly-dispersed Ru-based perovskites supported on reduced graphene oxide (A-RG) nanocomposites are prepared using different A-metal salts (Sr(NO₃)₂, Ba(NO₃)₂ and Ca(NO₃)₂). The procedure is based on a redox reaction between the metal precursors and graphene oxide (GO) using two different routes of reaction initiation: through thermal heating or by microwave-assisted heating. The resulting nanocomposites do not require further calcination, making this method less energy-demanding. In addition, no additional chemical reagents are required for either the GO reduction or the metal precursor oxidation, leading to an overall simple and direct synthesis method. The structure and morphology of the as-prepared A-RG (non-calcined) nanocomposites are characterized using various structural analyses including XRD, XPS, SEM/EDX and HR-TEM. Changing metal A in the perovskite as well as the “activation method” resulted in significant structural and morphological changes of the formed composites. SrRuO₃ and BaRuO₃ in combination with RuO₂ are obtained using a conventional combustion method, while SrRuO₃ (~1 nm size) in combination with Ru nanoparticles are successfully prepared using microwave irradiation. For the first time, a microwave-assisted synthesis method (without calcination) was used to form crystalline nano-CaRuO₃

EFFECT OF IRRIGATION SYSTEMS IMPROVEMENT ON WATER UNIT PRODUCTIVITY UNDER NORTH DELTA REGION CONDITIONS OF EGYPT

Several field trials and laboratory studies were conducted to evaluate the impact of the implementation of the activities and processes of the development of the field irrigation systems at ElMahmoudia area, El-Beheira Governorate, Egypt, during the successful growing seasons winter 2016/17 and summer 2017 to investigate the effect of irrigation systems improvement projects on water productivity. The measurements were conducted in a tertiary canal (Mesqa) at the head of Nekla canal (Arafa Mousa Mesqa). Water consumption values for different crops were calcaulated, and water application was calculated through calibrating the capacities of the pumps and recording the operation hours. The most important results were as follows: Applied irrigation water decreased after irrigation improvement. Applied irrigation water for wheat, rice, maize, sweet potatoes and watermelon before irrigation improvement were higher than the corresponding values after irrigation improvement by 9.0%, 15%, 11%, 15% and 10% respectively. The productivity of wheat, rice, maize, sweet potatoes and watermelon increased after irrigation improvement by 7.0%, 4.0%, 3.0%, 8.0% and 9.0% respectively. Water productivity increased after irrigation improvement, and the increase ratios for wheat, rice, maize, sweet potatoes were 14.0%, 16.0%, 13.0%, 20.0%, and 18.0% respectively

Torsional and Shear Wind Loads on Flat-Roofed Buildings

There is limited information available on wind-induced torsional loads on buildings. This paper presents results of wind tunnel tests carried out on a series of models of low- and medium-rise buildings. Four buildings with the same plan dimensions but different heights (6, 12, 25 and 50 m) were tested in a simulated open terrain exposure for different wind directions. Synchronized wind pressure measurements allowed estimating instantaneous base shear forces and torsional moments on the tested rigid building models. Results were normalized and presented in terms of mean and peak values of shear and torsional coefficients for two load cases, namely: maximum torsion and corresponding shear, and maximum shear and corresponding torsion. Comparison of the wind tunnel test results with current torsion- and shear-related provisions in the American Standard as well as the Canadian and European codes demonstrates significant discrepancies. The findings of this study could assist wind code and standards committees to improve provisions for wind-induced torsional loads on buildings