25 research outputs found

    Building overcooling in warm climates

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    The Energy Cost of Cold Thermal Discomfort in the Global South

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    EXTREME COLD DISCOMFORT IN EXTREME HOT CLIMATES, A STUDY OF BUILDING OVERCOOLING IN OFFICE BUILDINGS IN QATAR

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    Indoor cold discomfort in Qatar due to “building overcooling” is increasing, as air-conditioning prevails, and global temperatures rise. Overcooling is not dependent only on the inappropriate design of cooling systems, but on “international” thermal comfort standards that are not customized for warm climates. International standards are unintentionally biased towards cooler climates and cultures, the application of which in warm climates result in colder indoor temperatures observed by building occupants and increased cooling energy demand. Overcooling is an over-expenditure of energy, resulting in uncomfortably cold indoor thermal conditions, and unnecessary carbon emissions. In this study, the analysis of field data from 6 office buildings in Doha in a range of indoor thermal conditions and investigation of overcooling on occupant comfort and building performance is conducted. The analysis uncovers over 35% of occupants state being uncomfortably cold and a consensus across the surveys highlight comfortable temperatures higher by 2°C from current setpoint temperatures. Greater occupant comfort and energy efficiency are found by increasing the indoor temperature setpoints investigated through thermal comfort analysis and energy simulation models. Around 50% decrease in occupant discomfort and a 15% decrease in cooling energy demand is found. Such an adjustment in Qatar would improve occupant comfort levels and reduce cooling energy demand throughout the existing office building stock

    The Future of Thermal Comfort in a Warming World

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    Building cooling energy demand in the warmer climates of the world is increasing due to population growth and built environment expansion. Currently, cooling energy demand is increasing at a rate of 8% per annum, and this is projected to increase more rapidly with global warming. However, much of this demand is driven by unsustainably low indoor building temperature set points, that are also fundamentally seen as undesirable by most building occupants. In this study, we examine the effect of this “overcooling” in a changing climate using data from Qatar as a case study of a location with high average and peak external temperatures. Field data from 4 buildings in public and private settings demonstrate that cold discomfort is about 20 percentage points higher than warm discomfort due to excessive air-conditioning. Computer energy simulations using morphed future weather data and the extrapolated effect of observed low internal building temperatures, demonstrate that overcooling exacerbates the effect of a warming world by 16 percentage points. In other words, the use of more climatically appropriate thermal comfort standards that avoid unnecessary overcooling could reduce 28% of global carbon emissions in a future warmed world. As anecdotal evidence of excessive cooling in other warm climates demonstrates that the effects of overcooling are true, the reduction of building overcooling results in a greater achievement of thermal comfort, a decrease in cooling energy consumption, and a decline in carbon emissions across the warm climates of the world

    A FRAMEWORK FOR THE EVALUATION OF CYBERSECURITY EFFECTIVENESS OF ABU DHABI GOVERNMENT ENTITIES

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    Cyberspace has become one of the new frontiers for countries to demonstrate their power to survive in the digitized world. The UAE has become a major target for cyber conflicts due to the rapid increase in economic activity and technology. Further, the widespread use of the internet in the region to the tune of 88% by the end of 2014 has exposed the critical infrastructure to all forms of cyber threats. In this dissertation, the researcher presents a detailed study of the existing cybersecurity defences globally and an investigation into the factors that influence the effectiveness of cybersecurity defences in Abu Dhabi government entities. Further, the role of cybersecurity education, training, and awareness in enhancing the effectiveness of cybersecurity and the role of senior management in providing strategic direction to government entities on cybersecurity are evaluated in addition to determining the contribution of strategic planning and technology level in ensuring an effective cybersecurity system. The study has evaluated the level of Cybersecurity Effectiveness (CSE) in Abu Dhabi Government Entities and the results show that Science and Technology entity performed better than all other Entities with CSE Mean = 4.37 while Public Order showed the least performance with CSE Mean = 3.83 and the combined model of six factors with R-square value 0.317 after multiple regression implying that 32% change in CSE in the government entities is occurring due to the six (6) independent variables used in the study. Further, results show that management has the responsibility of putting in place strategies, frameworks and policies that respond appropriately to the prevention, detection and mitigation of cyberattacks. Results further indicate that culture-sensitive training and awareness programmes add to the quality and effectiveness of cybersecurity systems in government entities. Further, study findings reveal that qualified and experienced personnel in government entities show a greater understanding of cyber and information security issues. Finally, the researcher proposes a cybersecurity framework and a checklist, with checkpoints, for evaluating the effectiveness of cybersecurity systems within government entities and future research interventions

    Freezing from the heat:Building overcooling in Qatar

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    Qatar has the unfortunate reputation of the country with the highest per-capita carbon emissions in the world, 15% of which is due to space cooling demand. We investigate the extent to which this demand is driven by ‘overcooling’ in non-domestic buildings, that is low indoor set-points resulting in wasted energy and cold thermal discomfort. Using a recently developed overcooling metric, ISO 7730 compliant sensors and occupant survey data comprising 2,472 responses from eight morphologically diverse office buildings, we find that 32% of occupants can be classed as uncomfortably cold. Our analysis implicates the application of the ‘international’ ASHRAE 55 thermal comfort standard in the observed overcooling. Using computer models of the studied buildings, we find that this overcooling is responsible for 27% of their cooling energy demand, translating to 4% of national cooling energy demand and 2% of carbon for all non-domestic buildings. Thus, a simple upward adjustment of set-point temperatures by ∼ 2°C in non-domestic buildings would greatly improve comfort and reduce energy consumption and carbon emissions without changing the building or its systems. This suggests an urgent need for a new localised thermal comfort standard, with wider regional applicability due to similar culture and climates.</p

    Thermal comfort standards in the Middle East: Current and future challenges

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    Cooling energy demand has increased three-fold in the Middle East (ME) over the last 30-years. This is driven by the need to maintain thermal comfort in an extremely hot climate, and supported by rising incomes, falling costs of air-conditioning and growth in the number of buildings. The definition of thermal comfort in these buildings is drawn from “international” standards, which, though empirically derived, have no basis data from this region. Hence, we ask, to what extent do indoor conditions in the ME fall within the standards recommended range of thermal comfort, and when they do, whether they are found to be comfortable by their occupants. We present the first large-scale study of thermal comfort in the ME, consisting of two approaches: (i) a meta-analysis of data from existing studies, (ii) independent field data covering four countries representing 27% of the region's population, 31 air-conditioned buildings of different types, including “green” buildings, and 1,101 subjects. The meta-analysis demonstrates that current thermal comfort standards fail to predict thermal sensation of 94% of occupants. Our own data show that, while indoor conditions are within standards-recommended ranges 58% of the time, only 40% of occupants find these conditions acceptable. We find evidence of overcooling in summers, with 39% occupants expressing cold discomfort. Computer models suggest that this is likely to have increased annual cooling energy demand between 13% and 20%, compared to non-overcooled conditions. These results suggest the necessity of localised thermal comfort standards that mitigate excess cooling energy demand, without compromising occupant thermal comfort.</p

    Effects of combined treatment of probiotics and metformin in management of type 2 diabetes:A systematic review and meta-analysis

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    Background: Lifestyle changes and dietary intervention, including the use of probiotics, can modulate dysbiosis of gut microbiome and contribute to the management of type 2 diabetes mellitus (T2DM). This systematic review and meta-analysis aim to assess the efficacy of metformin plus probiotics versus metformin alone on outcomes in patients with T2DM. Methods: We searched MEDLINE and EMBASE from inception to February 2023 to identify all randomized controlled trials (RCTs), which compared the use of metformin plus probiotics versus metformin alone in adult patients with T2DM. Data were summarized as mean differences (MD) with 95 % confidence interval (CI) and pooled under the random effects model. Findings: Fourteen RCTs (17 comparisons, 1009 patients) were included in this systematic review. Pooled results show a significant decrease in fasting glucose (FG) (MD = −0.64, 95 % CI = −1.06, −0.22) and HbA1c (MD = −0.29, 95 % CI = −0.47, −0.10) levels in patients with T2DM treated with metformin plus probiotics versus metformin alone. The addition of probiotics to metformin resulted in lower odds of gastrointestinal adverse events (Odds ratio = 0.18, 95 % CI = 0.09, 0.3.8; I2 = 0 %). Conclusions: The addition of probiotics to metformin therapy is associated with improvement in T2DM outcomes. However, high-quality and adequately reported RCTs are needed in the future to confirm our findings.</p

    Haematological abnormalities and risk of covid-19 infection in adult patients attending primary healthcare settings

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    Centres for Disease Control and prevention (CDC) reports that there are limited data and information about the impact of underlying medical conditions and the risk of infection. To date, there are no studies that report on the risk of infection among patients with haematological diseases or abnormalities. This cross-sectional study reports on the baseline complete blood count in patients attending publicly funded primary care settings with a diagnosis of suspected COVID-19 infections in the state of Qatar. The study will report on the descriptive characteristics of the population, including gender, age and prior abnormalities to their blood test results. We will compare the results of those with positive and negative PCR test results, where appropriate. Nine hundred sixty-two adult patients attended publicly funded primary health care settings in the state of Qatar between February the 10th and April the 30th 2020 with a diagnosis of suspected COVID-19 infections had prior recorded blood investigations in the last six months and were included in this study. The population was young, mean of age is 38.8±11.6. (Median: 36 [Min: 19-Max: 85]). Complete blood count of the sample had minimal missing data points. Females were more presented in our samples, Female (n=560, 58.21%) and Male (n=402, 41.79%). Most of our sample had a documented PCR test result, negative (n=831, 86.38%); positive (n=123, 12.79%) and missing (n=8, 0.83%). Low haemoglobin values (n=265, 27.5%) and low red blood cell count (n =170, 17.7%) were the most prevalent complete blood count abnormality in the population. Leukopenia was less common (n=50, 8.2%). Most of the population had normal platelet count (n=895, 93%). Gender was the most influential factor in our sample to increase the odds of having a positive PCR test Non-results; males were more likely to be affected (P<0.001, Chi-square test) (OR 2.56, 95% CI 1.73-3.77). Categories for haematological abnormalities were not associated with increased risk of having a positive PCT test result. In a population attending primary healthcare settings with early presentation of symptoms of COVID-19 infection, the risk of infection among our cohort was not affected by the prior haematological values of those patients. Gender was the most influential parameter in the risk of infection in our population. Analysis of the results using gender-specific categories for different haematological parameters suggested that patients with abnormal haematological values were not at increased risk of having a positive COVID-19 infection
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