Applying Passive Cooling at an Urban Level: Case Study of Dubai, UAE

This research employs the integrative process of sustainable urbanism by applying passive design strategies to promote a sustainable neighbourhood lifestyle. A selected neighbourhood in Dubai is analysed and assessed in terms of its existing achievements regarding sustainability. It does so by simulating a site’s potential, its limitations, characteristics, existing buildings, transportation status, climate, and the Dubai culture in order to optimize and develop design criteria that meet all the requirements at different levels for a sustainable neighbourhood. To permit this, five passive cooling strategies are applied. The methodology adopted for this study is the assessment of the implications of proposed designs through the use of Envi-met software simulation. As per LEED a variety of facilities are included, and land use is differentiated to enhance social interaction and to meet all the daily needs of community users in such a way as to maximize the potential of a sustainable urban design process compared with the conventional way. The sustainable corridor was also oriented toward the northwest which helped generate many wind loops towards in the direction of the central plaza and the community hall and which increased wind speed by 6m/s. Additionally, in the proposed design, open spaces and green areas were increased by 30% through the creation of a major central plaza, a walkable environment, and water features to enhance livability and comfort in the community. Additional daily facilities and entertainment destinations are provided to capitalize on the proposed open spaces. The study yielded several significant findings; most notable was the reduction of surface temperature by approximately 2.5 degrees centigrade as a result of increasing the green areas by 30% and introducing a large water body and water features on-site

Towards sustainable residential buildings in the kingdom of Saudi Arabia.

Residential buildings are not only a major energy consumer, but also have considerable ecological impact. Quite often, architects can constitute a large part of the problem of tackling climate change. It is notable, however, that architects around the world have recently been encouraged to embrace the principles of sustainable design, which essentially aims to promote a suite of sustainable architectural practices such as those centred on enhancing household energy and water efficiency. Nonetheless, there seems to be a comparatively limited interest in pursuing the sustainability agenda among architects in the Middle East. In addition, there has been a corresponding dearth of academic research on this topic in spite of its apparent importance. This thesis considers the case of Saudi Arabia, and analyses the energy and water consumption of its current residential buildings in the context of two different climatic settings in the country, with the ultimate aim of establishing guidelines towards achieving sustainable architectural practices within the Saudi residential sector . An extensive literature review has been conducted in order to establish a broad understanding of existing sustainable architectural practices around the world. Using available literature, the thesis also examines both the current status of sustainability within the Saudi building sector, and the need for sustainable residential buildings in Saudi Arabia. Current energy and water consumption within two typical Saudi houses (an apartment complex and villa) were analysed using simulation software packages. Next, a number of design-oricntated energy and water conservation measures were suggested, and their serving potential assessed. In addition, especially as for this Ph.D. research, fourteen highly-informed Saudi stakeholders were interviewed in order to both validate the simulation results and to engage in in-depth discussions on ways of making residential buildings within Saudi Arabia more sustainable. Ultimately, a number of barriers that currently impede a transition towards a sustainable residential sector in Saudi Arabia have been identified. The thesis goes further and provides a number of design and non-design related strategies that have the potential to change the status quo with regard to the limited application of sustainable architectural principles within Saudi residential buildings

SCREENING OF SOME EGYPTIAN PLANT EXTRACTS FOR BIOLOGICAL ACTIVITY AGAINST SOME PATHOGENIC BACTERIA

Plants and plant by-products are now gaining attractiveness in treatment of bacterial infections and food preservation. The objective of this study was to assess antibacterial activity of some Egyptian plant and plant by-products against the locally pathogenic isolates from patients having infectious diseases in our country. Screening of antibacterial activity of ethanol, methanol and hexane extracts of some plants: grape leaves (Vitis vinifera), mulberry leaves (Morus alba), mallow leaves (Corchorus olitorius) and lemon leaves (Citrus limon) toward Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella sp., were investigated. Antibacterial activity was performed by the agar disc diffusion method. The ethanol and methanol extract of tested plant leaves showed promising antibacterial activities against both Gram-positive and Gram-negative tested bacterial isolates due to its great ability to extract those polyphenolic and biological active compounds from natural sources which effectively act against broad spectrum bacteria. Ethanol followed by methanol were found to be the best solvents of choice to extract natural products to get maximum health and medicinal benefits. The results revealed that the extraction efficiency increase with polarity increasing of the solvents, hence the highest extraction done with ethanol and methanol and the lowest extraction with nonpolar solvent n-hexanedid not exhibit any activity against all the tested bacteria. Irradiation at 5 and 10 kGy did not significantly affect the antibacterial activity of all tested plant leaves. Results indicate the potential of these plants for further work on isolation and characterization of the active compounds responsible for antibacterial activity and its exploitation as therapeutic agent

Titanium nanoparticles (TiO2)/graphene oxide nanosheets (GO): an electrochemical sensing platform for the sensitive and simultaneous determination of benzocaine in the presence of antipyrine.

An effective electrochemical sensing platform for the simultaneous determination of benzocaine (BEN) and antipyrine (ANT) based upon titanium dioxide nanoparticle (TiO2)/graphene oxide nanosheet (GO) bulk modified carbon paste electrodes (TiO2-GO/CPE) is reported. The TiO2-GO/CPE electrochemical sensing platform is found to exhibit linear ranges from 1.0 × 10-6 to 1.0 × 10-4 M and 1.2 × 10-8 to 8.0 × 10-5 M for BEN and ANT, respectively. The TiO2-GO/CPE sensor is explored towards the analysis of BEN and ANT in oral fluid (saliva) and pharmaceutical products. The synergy between the graphene oxide nanosheets and titanium dioxide nanoparticles results in a dramatic enhancement in the sensitivity of the sensor through a combination of increased surface area and improved electron transfer kinetics compared to other electrode alternatives. The fabricated TiO2-GO/CPE exhibits high sensitivity and good stability towards the sensing of BEN and ANT and has the potential to be utilised as a clinical assay and QA in pharmaceutical products

Neurological manifestations of COVID-19 in adults and children

Different neurological manifestations of coronavirus disease 2019 (COVID-19) in adults and children and their impact have not been well characterized. We aimed to determine the prevalence of neurological manifestations and in-hospital complications among hospitalized COVID-19 patients and ascertain differences between adults and children. We conducted a prospective multicentre observational study using the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) cohort across 1507 sites worldwide from 30 January 2020 to 25 May 2021. Analyses of neurological manifestations and neurological complications considered unadjusted prevalence estimates for predefined patient subgroups, and adjusted estimates as a function of patient age and time of hospitalization using generalized linear models. Overall, 161 239 patients (158 267 adults; 2972 children) hospitalized with COVID-19 and assessed for neurological manifestations and complications were included. In adults and children, the most frequent neurological manifestations at admission were fatigue (adults: 37.4%; children: 20.4%), altered consciousness (20.9%; 6.8%), myalgia (16.9%; 7.6%), dysgeusia (7.4%; 1.9%), anosmia (6.0%; 2.2%) and seizure (1.1%; 5.2%). In adults, the most frequent in-hospital neurological complications were stroke (1.5%), seizure (1%) and CNS infection (0.2%). Each occurred more frequently in intensive care unit (ICU) than in non-ICU patients. In children, seizure was the only neurological complication to occur more frequently in ICU versus non-ICU (7.1% versus 2.3%, P < 0.001). Stroke prevalence increased with increasing age, while CNS infection and seizure steadily decreased with age. There was a dramatic decrease in stroke over time during the pandemic. Hypertension, chronic neurological disease and the use of extracorporeal membrane oxygenation were associated with increased risk of stroke. Altered consciousness was associated with CNS infection, seizure and stroke. All in-hospital neurological complications were associated with increased odds of death. The likelihood of death rose with increasing age, especially after 25 years of age. In conclusion, adults and children have different neurological manifestations and in-hospital complications associated with COVID-19. Stroke risk increased with increasing age, while CNS infection and seizure risk decreased with age

Using passive cooling strategies to improve thermal performance and reduce energy consumption of residential buildings in U.A.E. buildings

Passive design responds to local climate and site conditions in order to maximise the comfort and health of building users while minimising energy use. The key to designing a passive building is to take best advantage of the local climate. Passive cooling refers to any technologies or design features adopted to reduce the temperature of buildings without the need for power consumption. Consequently, the aim of this study is to test the usefulness of applying selected passive cooling strategies to improve thermal performance and to reduce energy consumption of residential buildings in hot arid climate settings, namely Dubai, United Arab Emirates. One case building was selected and eight passive cooling strategies were applied. Energy simulation software – namely IES – was used to assess the performance of the building. Solar shading performance was also assessed using Sun Cast Analysis, as a part of the IES software. Energy reduction was achieved due to both the harnessing of natural ventilation and the minimising of heat gain in line with applying good shading devices alongside the use of double glazing. Additionally, green roofing proved its potential by acting as an effective roof insulation. The study revealed several significant findings including that the total annual energy consumption of a residential building in Dubai may be reduced by up to 23.6% when a building uses passive cooling strategies