Design principles for thermally comfortable and low energy homes in the extreme hot-humid climatic Gulf region, with reference to Dammam, Saudi Arabia

Indoor thermal comfort and its consequent energy consumption, are an increasingly important area of consideration in both developed and developing countries. The Gulf States, characterised by their composite extreme hot-humid climate and Airconditioning dependent society are renowned for their high energy consumption. The main aim of this research is to review and report on ways to enhance occupant thermal comfort in homes through improved building and system design and use that minimises energy consumption possible, in the extreme climate of Dammam, Saudi Arabia. The thesis does this by measuring and analysing the thermal performance of the buildings, the thermal satisfaction and comfort responses of their occupants and the energy consumption in them during August 2013 for the summer period and January 2014 for the winter period of the study. The comfort of occupants was assessed using the adaptive thermal comfort method. Neutral indoor air temperatures were, in several homes, surprisingly high. Moreover, most of the studied dwellings do not represent thermally comfortable homes as defined within either PMV or adaptive comfort limits. The study went on to review a broad range of factors that might strongly influence neutral temperatures indoors including the properties of the dwellings, occupant behaviours and attitudes towards high energy demand, loads and costs. The findings are discussed and conclusions drawn on individual design features that contribute to the comfort or discomfort experienced by occupants. It was found that lifestyle, attitudes and other socio-cultural factors have a clear influence on the comfort and in turn energy use in individual dwellings. Although several respondents did not sincerely care about the electricity as it is cheap, in late 2015 the Saudi government hiked the price of domestic energy bills by 60% as a result of low oil prices, putting pressure on many ordinary families to take more notice of their day to day living expenses. The recent electricity price hike provides an economic impetus for the design guidance proffered in the conclusions of this thesis to be taken seriously by householders and implemented by both them and regulating authorities in order to enhance domestic buildings and in turn reduce the CO2 emissions to the global atmosphere. The conclusion of this study is broadly applicable to other regions with similar climatic conditions and cultural contexts such as the Gulf countries

Crystal structures of 4-phenylpiperazin-1-ium 6-chloro-5-ethyl-2,4-dioxopyrimidin-1-ide and 4-phenylpiperazin-1-ium 6-chloro-5-isopropyl-2,4-dioxopyrimidin-1-ide

The title molecular salts, C10H15N2+·C6H6ClN2O2−, (I), and C10H15N2+·C7H8ClN2O2−, (II), consist of 4-phenylpiperazin-1-ium cations with a 6-chloro-5-ethyl-2,4-dioxopyrimidin-1-ide anion in (I) and a 6-chloro-5-isopropyl-2,4-dioxopyrimidin-1-ide anion in (II). Salt (I) crystallizes with two independent cations and anions in the asymmetric unit. In the crystal structures of both salts, the ions are linked via N—H...O and N—H...N hydrogen bonds, forming sheets which are parallel to (100) in (I) and to (001) in (II). In (I), the sheets are linked via C—H...Cl hydrogen bonds, forming a three-dimensional framework

Progressive Collapse Resistance of RC Beam–Slab Substructures Made with Rubberized Concrete

Abnormal loads can produce localized damage that can eventually cause progressive collapse of the whole reinforced concrete (RC) structure. This might have devastating financial repercussions and cause numerous severe casualties. Numerical simulation, using the finite element method (FEM), of the consequences of abnormal loads on buildings is thus required to avoid the significant expenses associated with testing full-scale buildings and to save time. In this paper, FEM simulations, using ABAQUS software, were employed to investigate the progressive collapse resistance of the full-scale three-dimensional (3D) beam–slab substructures, considering two concrete mixes, namely: normal concrete (NC) and rubberized concrete (RuC) which was made by incorporating crumb rubber at 20% by volume replacement for sand. The FEM accuracy and dependability were validated using available experimental test results. Concrete and steel material non-linearity were considered in the FE modelling. The numerical study is extended to include eight new models with various specifics (a set of parameters) for further understanding of progressive collapse. Results showed that slabs contribute more than a third of the load resistance, which also significantly improves the building’s progressive collapse resistance. Moreover, the performance of the RuC specimens was excellent in the catenary stage, which develops additional resilience to significant deformation to prevent or even mitigate progressive collapse

Coxiella burnetii, the causative agent of Q fever in Saudi Arabia: molecular detection from camel and other domestic livestock

AbstractObjectiveTo detect Coxiella burnetii (C. burnetii) DNA in clinical specimens from camel, goats, cattle and sheep in the Kingdom of Saudi Arabia.MethodsA total of 367 clinical samples including blood, milk, faeces and urine were collected from different livestock and subjected to PCR amplification using primers which amplify transposon-like region and transposase gene.ResultsPositive amplification from both regions was obtained from camel, goats and cattle but not from sheep. A percentage of 10.8% samples yielded positive PCR amplification from both blood and milk, where 15 of 139 blood and 16 of 148 milk samples were positive. Faeces and urine showed higher percentages of positive samples reaching 40.8% and 23.8% respectively.ConclusionsThe preferred route of shedding in camel appeared to be the faeces followed by urine, while that of goats appeared to be the faeces and that of the cattle appeared to be the milk

The Main and Most Important Radiological Role in the Future of the Healthcare Management: A Systematic Theoretical Review

This study aimed at exploring the main and most important Radiological role in the future of the healthcare management through a systematic theoretical review.  As radiology plays the key role of jumping in to investigate dis­ease diagnosing, staging, monitoring and following it over time and offering expertise and consultation on disease states. And highlighting that this discipline is now in a stage of profound metamorphosis through out of building the value of radiology and the radiologist, to empower radiologists to be larger contributors to care teams. The study concluded that the current radiology model, though useful in many respects, needs to adapt to changing economic incentives and in one way or another align itself with those of the clinicians radiologists serve.

Effect of Aromatase Inhibitor Letrozole on the Placenta of Adult Albino Rats: A Histopathological, Immunohistochemical, and Biochemical Study

Background: Letrozole, an aromatase inhibitor, has recently been introduced as the preferred treatment option for ectopic pregnancy. To date, no study has investigated the effect of letrozole alone on placental tissue. The present study aimed to evaluate the effect of different doses of letrozole on the placenta of rats and to clarify the underlying mechanism. Methods: Sixty pregnant female rats were equally divided into three groups, namely the control group (GI), low-dose (0.5 mg/Kg/day) letrozole group (GII), which is equivalent to the human daily dose (HED) of 5 mg, and high-dose (1 mg/Kg/day) letrozole group (GIII), equivalent to the HED of 10 mg. Letrozole was administered by oral gavage daily from day 6 to 16 of gestation. Data were analyzed using a one-way analysis of variance followed by Tukey’s post hoc test and Chi square test. P<0.05 was considered statistically significant.Results: Compared to the GI and GII groups, high-dose letrozole significantly increased embryonic mortality with a high post-implantation loss rate (P<0.001) and significantly reduced the number of viable fetuses (P<0.001) and placental weight (P<0.001) of pregnant rats. Moreover, it significantly reduced placental estrogen receptor (ER) and progesterone receptor (PR) (P<0.001) and the expression of vascular endothelial growth factor (P<0.001), while increasing the apoptotic index of cleaved caspase-3 (P<0.001).Conclusion: Letrozole inhibited the expression of ER and PR in rat placenta. It interrupted stimulatory vascular signals causing significant apoptosis and placental vascular dysfunction. Letrozole in an equivalent human daily dose of 10 mg caused a high post-implantation loss rate without imposing severe side effects

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Design of variation-tolerant synchronizers for multiple clock and voltage domains

PhD ThesisVascular plants comprise 20-30% lignin, constituting a considerable organic input to soils. Lignin is not necessarily preserved in soils, but the fate of its decomposition products in the wider environment is not well understood. Therefore, the overarching hypothesis tested herein was that a significant proportion of lignin is solubilised and lost from soils by transport in water. Solid phase extraction was used to extract lignin phenols from dissolved organic matter (DOM) from water outlets adjacent to major land use types (grazed grassland, deciduous woodland, and moorland) and compared to the lignin phenols from representative vegetation types, animal dungs and soils from each land use type. The phenols were identified and quantified using thermally assisted hydrolysis and methylation using tetramethylammonium hydroxide. Leachates from lysimeters treated with four vegetation types (grass, buttercup, ash, and oak) were sampled in a 22 month chronosequence, showing that some of the dominant phenols detected in the vegetation were also dominant in the respective DOM. A proportional relationship between increasing temperature and loss of representative lignin phenols in DOM was observed. Comparison of the dominant phenols in vegetation, soil and water sampled from field sites suggested specific lignin phenols could be used as biomarkers for different land uses. The concentrations of organic carbon-normalised total lignin phenols in the soils were similar to those in water, indicating that a considerable proportion of lignin in soils is lost via leaching. There was no significant difference in losses of lignin phenols between each land use type. Application of different rates of dissolved lignin to lysimeters indicated that the amount of water added was a dominant driver of transport through soil over 16 days, and that molecular structure also influenced transport rates of individual phenols. The impact of this research is that climate change (increased precipitation and warming) may significantly affect the loss of lignin by increased solubilisation and leaching from soils.NERC and BBSRC for funding this project and providing my stipen

Evolution of udder morphology, alveolar and cisternal milk compartment during lactation and their relationship with milk yield in Najdi sheep

A total of 30 multiparous Najdi ewes were used to study the evolution of udder morphology traits and milk fractions in the udder during suckling (3rd, 6th, 9th wk) and milking (10th, 11th, 12th wk) periods. During suckling period, daily milk yield was estimated by using the double oxytocin injections method 4-h after milking. During milking period, ewes were hand-milked once daily. Udder and teat morphology traits for all ewes were measured 4-h after milking. Udder compartments were evaluated 8-h after milking by using atosiban and oxytocin; milk samples of each fraction were collected. Najdi ewes had a medium and healthy udders (CMT < 1), with medium sized teats (length, 3.2 ± 0.1 cm and width, 1.7 ± 0.1 cm) attached at 35.7 ± 11° angle. Milk yield averaged 1.88 ± 0.18 and 0.44 ± 0.12 L d�1 during suckling and milking periods, respectively. A drop in milk yield (�75%, p < 0.01) was found in the transition from suckling to milking. Udder traits, teats angle and width, and distance between teats declined (p < 0.05) throughout lactation, whereas teat lengths did not show any change. Positive correlations (p < 0.05) were observed between milk yield and udder depth (r = 0.47-0.49), width (r = 0.31-0.39) and distance between teats (r = 0.26-0.39). The cisternal milk volumes decreased (p < 0.05) after weaning, whilst the corresponding percentages increased (p < 0.05). Cisternal milk accounted for 55% and 67% of the total udder milk during suckling and milking periods, respectively. Cisternal milk was positively correlated (r = 0.93, p < 0.05) with total milk yield. The percentages of protein and total solids in alveolar and cisternal milk increased significantly (p < 0.05) after weaning, whilst fat percentages in cisternal milk did not change. In conclusion, the evaluated Najdi ewes showed medium sized cisterns and teats, which considered adequate for machine milking. Udder morphology traits had positive correlations with milk yield and hence, can be utilized in breeding programs