The dimensions of many water streams, which satisfy proper hydraulic conditions, may not be compatible with the designed dimensions of an irrigation work that needs to be constructed in some locations. The design requirements of such irrigation works may involve a contraction in the channel width in the required location. This contraction, of course, affects different flow properties and the scour hole formed downstream of these structures. Therefore, the present experimental study aims to investigate the effect of the transition angle and the contraction on the flow properties and on the scour phenomenon downstream water structures. Through 460 experimental runs, carried out on 20 experimental models, the study proved that, for an efficient hydraulic performance and economic design, the best transition angle (θ) for the approaches of water structures is 30° with a relative contracted width ratio (r = b/B) not less than 0.6.

Schools in hot arid climate depend on courtyard to encourage students’ for social activity. In order to improve Outdoor Thermal Comfort (OTC), applying passive mitigation strategies in the courtyard is critical issue. This paper aims to improve students’ thermal comfort in school courtyards throughout the study of a public school with an E-shaped style in New Assiut City. Hence, different shading strategies (shading with different heights, vegetation, and hybrid) are simulated by using ENVI-met model v 5.0.0 to improve OTC for students in school courtyards. Firstly, monitoring was conducted inside outer courtyards. Then nine scenarios of passive strategies were implemented inside two courtyards with a ratio H/W = 0.4 and 0.7. After that, Physiological Equivalent Temperature (PET) was used to compare different scenarios. The results found, by applying hybrid orthogonal and diagonal staggered shading with trees in …

Extensive construction augmenting the infrastructure and real estate projects underpin
Saudi Arabia’s Vision 2030 of sustainable cities. A part of this struggle involves the transformation
of the existing infrastructure together with new construction, which generates a large amount of
construction and demolition waste (CDW). In the absence of a structured life cycle assessment (LCA)
framework, the waste management companies are planning future scenarios (phased expansions
of material recovery facilities to improve the recycling rate) primarily on economic grounds. This
study assesses the environmental impacts of the existing and planned CDW management practices
of the Saudi Investment Recycling Company in Riyadh City by dint of LCA. Impact 2002+ performs
life cycle impact assessment of the base case (45% recycling), four treatments (61, 76, 88, and 100%
recycling), and zero waste scenarios. The study demonstrates the benefits of current CDW (mixed
soil, concrete blocks, clay bricks, glazed tiles, and asphalt) recycling in terms of avoided impacts of
non-renewable energy, global warming, carcinogens, non-carcinogens, and respiratory inorganics
potentially generated by landfilling. For the treatment scenario of 100% recycling, CDW conversion
into a wide range of aggregates (0–50 mm) can replace 10–100% virgin aggregates in backfilling,
precast concrete manufacturing, encasements and beddings of water mains and sewers, manholes
construction, non-load bearing walls, and farm-to-market roads. To achieve long-term economic
and environmental sustainability, municipalities need to improve source segregation, handling, and
storage practices to enhance the existing (45%) recycling rate to 100% in the next five years and
approach the zero-waste scenario by 2030. The findings of the present study motivate the generators
for source reduction as well as encourage the recycling companies and concerned organizations in
the continuous performance improvement of the CDW management systems across Saudi Arabia on
environmental grounds, as an addition to the perceived economic benefits.

The need to enhance the performance of building façades and mitigate adverse environmental
impacts has promoted the hypothesis of integrating green materials towards sustainable
buildings. Façade designers tend to select building materials based on their green characteristics
(origin) or green performance; however, this study highlights the importance of integrating both
into the decision process. The main objective is to develop a new assessment process for selecting
green building façade materials based on green performance and green originality. Furthermore,
the evaluation framework considers four green building rating systems as a reference to allocate
credits for the relevant criteria. Applying the proposed criteria in this study helps maximize the
points for accreditation when incorporating green building materials in building façades. Moreover,
the Analytic Hierarchy Process (AHP) is used to assign the proposed criteria’s weighting importance
based on the four rating systems’ average points. After that, performing sensitivity analysis to
identify each criterion’s influence is conducted. The study concluded that involving minimum levels
of adverse impacts is the preferable criteria regarding the green origin concept. As for the green
performance, promoting the performance of indoor air quality is the most favorable selection criteria.

The spread of the COVID-19 pandemic caused a tremendous impact on our societies, including changes in household energy consumption. Using measured electricity use data from 500 homes in Ottawa, Canada, this study applies changepoint analysis, descriptive statistics, k-means clustering, and the corresponding change of electricity utility bills before and after COVID-19. Our analysis indicates that the average household daily electricity consumption increased by about 12% in 2020 relative to 2019, about one-third was due to warmer temperatures, with much of the rest due to the temperature-independent loads (e.g., lighting and appliances). Additionally, the highest five peak loads corresponding to post-COVID are significantly higher (15–20%) than peaks that occurred pre-COVID. The lockdown’s impact on household electricity use is not consistent, and there are noticeable differences among different months, seasons, and day types. Two clusters of household electricity use patterns emerged, with about one-third showing significant increases during the pandemic and the remainder showing only minor changes. On the other hand, in the summer, all customers’ electricity use profile patterns after the pandemic resemble the pattern before the pandemic. Yet, there is a significant increase (from 16.3 to 29.1%) in daily demand after COVID-19. Finally, the average increase in the utility bill post-COVID would be 9.71% if TOU rates were used instead of the flat rate that was implemented as a subsidy to consumers.