Modeling Radiation Heat Transfer for Building’s Cooling and Heating Loads: Considering the Role of Clear, Cloudy, and Dusty Conditions in Hot and Dry Climates

The influence of transient factors such as sky long wave radiation exchange and atmospheric aerosols (i.e., smog, and dust – made up of sand, clay, and silt) are not carefully considered in current building design and simulation models. Therefore, the research objective was to better understand and account for such variables, resulting in improved radiative predictive capabilities, especially important for hot and dry climates under different sky conditions including clean, cloudy, and dusty. Overall, results of this dissertation provided a better prediction method for sky long wave radiation exchange with a building’s roof and the impact of dust accumulation on energy use, especially for poorly and uninsulated residential buildings. The two most significant results for this study were (1) a new absorptivity model was introduced in an effort to relate a building’s exterior roof solar and thermal properties (absorptivity, reflectivity, and emissivity) to monthly averaged dust accumulation, and (2) a new dusty sky temperature model was introduced as a function of atmospheric aerosol optical depth to better account for dust impact on sky temperature prediction

Machine learning for improved detection and segmentation of building boundary

The first step in rescuing and mitigating the losses from natural or man-made disasters is to assess damaged assets, including services, utilities and infrastructure, such as buildings. However, manual visual analysis of the affected buildings can be time consuming and labour intensive. Automatic detection of buildings, on the other hand, has the potential to overcome the limitations of conventional approaches. This thesis reviews the existing methods for the automated detection of objects using multi-source geospatial data and presents two novel post processing techniques. Effective building segmentation and recognition techniques are also investigated. Artificial intelligence techniques have been used to identify building boundaries in automated building-detection applications. Compared with other neural network models, the convolutional neural network (CNN) architectures based on supervised and unsupervised approaches provide better results by looking at the image details as spatial information of the entity in the frame. This research incorporates the improved semantic detection ability of Region-based Convolutional Neural Network (Mask R-CNN) and the segmentation refining capability of the conditional random field (CRF)s. Mask R-CNN uses a pre-trained network to recognise the boundary boxes around buildings. It also provides contour key points around buildings that are masked in satellite images. This thesis proposes two novel post-processing techniques that operate by modifying and detecting the building’s relative orientation properties and combining the key points predicted by the two head neural networks to modify the predicted contour with the help of the proposed novel snap algorithms. The results show significant improvements in the accuracy of boundary detection compared with the state-ofthe-art techniques of 2.5%, 4.6% and 1% for F1-Score, Intersection over Union also known as Jacard coefficient (IoU), and overall pixel accuracy, respectively. CNNs have proven to be powerful tools for a wide range of image processing tasks where they can be used to automatically learn mid-level and high-level concepts from raw data, such as images. Finally, the results highlight the potential of further approaches to these applications, such as the planning of infrastructure

The coastal fog and ecological balance for plants in the Jizan region, Saudi Arabia

Fog water collection provides a sustainable resource for watering of crops. The Jizan region is one of the smallest states in the Kingdom of Saudi Arabia (KSA) but very rich with unique flora, fauna, landscape diversity, and occurrence of fog. According to satellite data from the period between (1991–2021) the average visibility in this fog belt varied between 5 m and 100 m. Specific relief properties, such as elevation contrast, present rare space for flora preservation and sustainable fog utilization and use in the watering of crops. Some results showed that number of foggy days is not equal and can be divided in three big cycles. It was estimated that 8 × 1013 L, or 80 m3 of fresh water from fog per year, could be used for drinking and partly for farming in Jizan region from settlements Al Araq and Al Gandla, city of Jizan, Al Madaya, Al Mubarakiyah, Muwassam. This amount of water varied through time. The last observational period had large amount of water, 10 × 1013 L or 100 m3. The main methodologies used in this research were advanced GIS (Geographical Information Systems), Remote Sensing (RS), and numerical analysis. Satellite data were downloaded from National Oceanic and Atmospheric Administration (NOAA) and Landsat 8 and 9 satellite missions. This kind of alternative water may produce stability for three main plants in Jizan region, palm, wheat and olive. Typical arid regions in KSA can be transformed by water used from the fog

Characteristics of Sustainable Concrete with Partial Substitutions of Glass Waste as a Binder Material

[EN] Manufacturing waste has been quickly increasing over time as a result of the fast‑rising population as well as the consumption of foods that are thrown away dishonestly, resulting in environmental contamination. As a result, it has been suggested that industrial waste disposal may be considerably reduced if it could be integrated into cement concrete manufacturing. The aim of this study is to analyze the properties of concrete employing waste glass (WG) as a binding material in proportions of 5%, 10%, 15%, 20%, 25%, and 30% by weight of cement. The fresh property was assessed using a slump cone test, while mechanical performance was assessed using flexural, compressive, splitting tensile, and pull‑out strength after 7, 28, and 56 days. Furthermore, microstructure analysis was studied by scan elec‑ tronic microscopic (SEM), Fourier‑transform infrared spectroscopy (FTIR) and thermo‑gravimetric analysis (TGA) test. The results reveal that the addition of discarded glass reduces the workability of concrete. Furthermore, mechanical performance was increased up to a 20% substitution of waste glass and then gradually declined. Waste glass can be employed as a micro filler or pozzolanic material without affecting the mechanical performance of concrete, accord‑ ing to microstructure research.S

3D Magneto-buoyancy-thermocapillary convection of CNT-water nanofluid in the presence of a magnetic field

Anumerical study is performed to investigate the effects of adding Carbon Nano Tube (CNT) and applying a magnetic field in two directions (vertical and horizontal) on the 3D-thermo-capillary natural convection. The cavity is differentially heated with a free upper surface. Governing equations are solved using the finite volume method. Results are presented in term of flow structure, temperature field and rate of heat transfer. In fact, results revealed that the flow structure and heat transfer rate are considerably affected by the magnitude and the direction of the magnetic field, the presence of thermocapillary forces and by increasing nanoparticles volume fraction. In opposition, the increase of the magnetic field magnitude leads to the control the flow causing flow stabilization by merging vortexes and reducing heat transfer rate. © 2020 by the authors

Investigation of MPPT Techniques Under Uniform and Non-Uniform Solar Irradiation Condition-A Retrospection

A significant growth in solar photovoltaic (PV) installation has observed during the last decade in standalone and grid-connected power generation systems. The solar PV system has a non-linear output characteristic because of weather intermittency, which tends to have a substantial effect on overall PV system output. Hence, to optimize the output of a PV system, different maximum power point tracking (MPPT) techniques have been used. But, the confusion lies while selecting an appropriate MPPT, as every method has its own merits and demerits. Therefore, a proper review of these techniques is essential. A “Google Scholar” survey of the last five years (2015-2020) was conducted. It has found that overall seventy-one review articles are published on different MPPT techniques; out of those seventy-one, only four are on uniform solar irradiance, seven on non-uniform and none on hybrid optimization MPPT techniques. Most of them have discussed the limited number of MPPT techniques, and none of them has discussed the online and offline under uniform and hybrid MPPT techniques under non-uniform solar irradiance conditions all together in one. Unfortunately, very few attempts have made in this regard. Therefore, a comprehensive review paper on this topic is need of time, in which almost all the well-known MPPT techniques should be encapsulated in one paper. This article focuses on classifications of online, offline, and hybrid optimization MPPT algorithms, under the uniform and non-uniform irradiance conditions. It summarizes various MPPT methods along with their mathematical expression, operating principle, and block diagram/flow charts. This research will provide a valuable pathway to researchers, energy engineers, and strategists for future research and implementation in the field of maximum power point tracking optimization

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Evaluation and optimization of the performance and efficiency of a hybrid flat plate solar collector integrated with phase change material and heat sink

This study presents an experimental real case study on the performance optimization of a flat plate solar collector (FPSC) by integrating a layer of phase change material (PCM) and a heat sink. The system was tested under the semi-arid climatic conditions of Abha, Saudi Arabia. Based on preliminary experimental testing on conventional FPSCs, the novel composite structure of the PCM material was developed by mixing polyethylene glycol (PEG) and magnesium hydroxide (Mg (OH)2) in an absolute ethanol solution. The PEG/Mg (OH)2 PCM was installed beneath the pipe and had a lower supercooling value, a higher latent heat value, and thermal stable characteristic, thus increasing the thermal performance of the FPSC. The results showed that using a PCM ensured that the collector continued to deliver hot water for a longer period of time. Furthermore, a heat sink was attached to the PCM layer for proper temperature distribution. The results demonstrated that the FPSC equipped with a PCM and heat sink produced hot water for a longer period of time in the evening while having a lower output temperature in the morning. Also, the average daily FPSC thermal efficiency was enhanced by 6–8% by adding only PEG/Mg (OH)2 PCM as compared with conventional FPSCs and those with PCMs and heat sinks