45 research outputs found
The effects of rhythm on building openings and fenestrations on airflow pattern in tropical low-rise residential buildings
Effective passive airflow in low-rise residential buildings in hot-humid environment is crucial to maintaining good indoor thermal comfort for occupants. However, investigation of effects of the rhythm of window openings on achieving a passive airflow pattern in such buildings in the tropical climate of sub-Saharan Nigeria have been rarely studied. Therefore, this research aimed to evaluate the effects of the rhythm of window openings on passive airflow patterns for indoor thermal comfort in low-rise residential buildings in the hot-humid environment of Obosi, Nigeria. It involved experimental research using the Anemometer TA465 instrument for measuring wind velocity, relative humidity, and temperature of the purposively designated buildings in the three layouts of the study area for both wet and dry seasons. Employing the Yamane statistical formula, a sample size of 433 was obtained, and questionnaires were administered to occupants of the studied buildings and analyzed using categorical Regression Analysis (CATREG). The regression analysis showed that p=0.000, i.e. p<0.05 indicating that there was a significant relationship between the type and sizes of windows (elements used in measuring rhythm) and the intensity or force of breeze (a measure of passive airflow pattern). Further analysis of the data involved the use of Autodesk CFD 2018 (Computational Fluid Dynamics) for building wind flow simulations. The result showed variations in temperature levels (indications of differences in indoor thermal comfort) of various indoor spaces of the investigated designated floors and buildings, especially ground floors and the top-most floors of the buildings. The study underscored the need to use architectural rhythm design strategies to create a positive impact on airflow patterns in low-rise buildings, especially in densely built-up urban areas. The results of this study are instructive in noting that in order to attain passive airflow in buildings in the face of challenge of land restrictions, vertical stacking of building floors could be used once an adequate rhythm of window openings is adopted
Impact of Landuse Morphology on Urban Transportation
People, cities, nations and the world, in general, would remain largely underdeveloped without transportation systems. However, Transportation puts significant pressure on land use and poses a great challenge to urban sustainability in developing countries. This study examines the influence of Land use structure on Intra-urban transportation in the developing city of cities in the West African sub-region – using Enugu city as a case study. The study uses a descriptive research method. A survey was carried out in six districts within the Enugu metropolis based on a stratified, purposive sampling technique. Questionnaires were used as data collection instruments; 400 respondence participated in the study employing Yamane equation. Furthermore, a twelve-hour (7 am to 7 pm) traffic count was conducted to assess traffic volume. The study finding revealed that Transportation within the urban areas is significantly impacted by Land-use structure, city morphology, neighbourhood characteristics in terms of population and residential density of the city. The hypothesis suggests no significant difference between the various land uses across the Enugu metropolis (p = 0.129). It was also discovered that an average of 122,431 Passenger Car Units (PCU) constantly ply the metropolis roads to service a total population of 564,725 daily, indicated a high rate of car dependency. The study surmises that land use generates vehicular traffic, which impacts the socio-economic environment and the effectiveness of the transportation system. The significance of this study is that the findings contribute to the existing knowledge base that would advance stratic policy formation towards acceleration of the uptake of sustainable urban transportation systems in the region. Doi: 10.28991/cej-2021-03091758 Full Text: PD
The Effects of Rhythm on Building Openings and Fenestrations on Airflow Pattern in Tropical Low-Rise Residential Buildings
Effective passive airflow in low-rise residential buildings in hot-humid environment is crucial to maintaining good indoor thermal comfort for occupants. However, investigation of effects of the rhythm of window openings on achieving a passive airflow pattern in such buildings in the tropical climate of sub-Saharan Nigeria have been rarely studied. Therefore, this research aimed to evaluate the effects of the rhythm of window openings on passive airflow patterns for indoor thermal comfort in low-rise residential buildings in the hot-humid environment of Obosi, Nigeria. It involved experimental research using the Anemometer TA465 instrument for measuring wind velocity, relative humidity, and temperature of the purposively designated buildings in the three layouts of the study area for both wet and dry seasons. Employing the Yamane statistical formula, a sample size of 433 was obtained, and questionnaires were administered to occupants of the studied buildings and analyzed using categorical Regression Analysis (CATREG). The regression analysis showed that p=0.000, i.e. p<0.05 indicating that there was a significant relationship between the type and sizes of windows (elements used in measuring rhythm) and the intensity or force of breeze (a measure of passive airflow pattern). Further analysis of the data involved the use of Autodesk CFD 2018 (Computational Fluid Dynamics) for building wind flow simulations. The result showed variations in temperature levels (indications of differences in indoor thermal comfort) of various indoor spaces of the investigated designated floors and buildings, especially ground floors and the top-most floors of the buildings. The study underscored the need to use architectural rhythm design strategies to create a positive impact on airflow patterns in low-rise buildings, especially in densely built-up urban areas. The results of this study are instructive in noting that in order to attain passive airflow in buildings in the face of challenge of land restrictions, vertical stacking of building floors could be used once an adequate rhythm of window openings is adopted. Doi: 10.28991/CEJ-2023-09-08-016 Full Text: PD
Transit, walking and cycling infrastructure and sustainable development in Enugu city, Nigeria.
In a predominantly urban world, people's ability to move within cities is a critical driver of sustainability. The transportation system which constitutes a large percentage of the physical urban environment provides mobility and aid economic sector. However, it contributes to several major environmental pressures including pollution, congestion, accidents, waste accumulation, resources depletion and disruption of nature. While urban population growth and
increase in economic activities combine to generate higher demand for transportation services and heighten the problem. How to effectively deal with these imposing threats and simultaneously provide optimal mobility for city dwellers is the backbone of this research. Drawing experiences from developed cities, the study used Achara layout in Enugu as a case study. From observation, surveys and published literature data were collected and analysed qualitatively. The primary data include, physical traffic count, existing road character, traffic infrastructure and demographic statistics. Findings show the extensive sterility of Enugu’s urban infrastructure to motorized traffic and lack of provision for walking and cycling. It recommends strategies for planning and managing the urban environment which recognizes and acknowledged the social, environmental and economic realities. The conclusion demonstrates that cities designed for pedestrians and cyclist are cities designed for people and sustainable development
An Examination of Site Meetings: Essential Factors and Implications on Building Quality in Construction Projects within Higher Institutions in Ekiti State
The building and construction industry (BCI) is made of diverse professionals and despite its emphasis on quality project delivery, the essentials of site meetings have not been adequately explored. The study examined the fundamental aspects of Site Meetings and their impact on the execution of construction projects in the building sector, specifically focusing on higher education institutions in Ekiti State, Nigeria. An online survey questionnaire was used and administered to the Consultants and Contractors, within Higher Institutions in Ekiti State, and only seventy-four (74) Respondents filled out the questionnaire and submitted it. The results indicated that 67.6% and 31.1% strongly agreed and agreed respectively that site minutes are important to project implementation. 50% each strongly agreed and agreed that the agenda is a critical tool for project implementation. 37.7% of respondent do not have a definite time for sending notice of a meeting while 10.8% do not have an agenda for their site meetings, also, 52.7% make the minutes of site meetings available before the meeting and 47.3% during the meeting. The study recommended that all stakeholders should take the essentials seriously. Notice of meetings, agendas, and Minutes should be prepared and sent ahead of site meeting dates
Keeping up with changing technologies: The nexus between architecture and engineering
Advancements in technology are fundamentally transforming architectural and engineering domains within the building and construction sector. This study investigates the intersection of both fields in assimilating emerging innovations by eliciting empirical perspectives from practitioners. Embracing a quantitative approach, a survey was conducted among 203 architects and 392 engineers within Enugu metropolis, Nigeria using proportionate random sampling. Results were analyzed using descriptive statistics, revealing insights into awareness, perception, and collaboration concerning emerging technologies. Findings revealed high awareness but uneven adoption of building information modeling tools, with 97.3% of architects employing them versus only 25.4% of engineers. Although virtual reality and cloud-based platforms showed promise for enhancing project coordination, actual usage lagged significantly, likely owing to systemic and attitudinal barriers. However, respondents strongly endorsed tighter, technologically unified partnerships to smooth industry transformation, necessitating digital literacy interventions, supportive policy and binding protocols bridging persistent digital divides stalling seamless innovation diffusion along construction value chains
Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021
Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic
Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
Background: Understanding the health consequences associated with exposure to risk factors is necessary to inform public health policy and practice. To systematically quantify the contributions of risk factor exposures to specific health outcomes, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 aims to provide comprehensive estimates of exposure levels, relative health risks, and attributable burden of disease for 88 risk factors in 204 countries and territories and 811 subnational locations, from 1990 to 2021. Methods: The GBD 2021 risk factor analysis used data from 54 561 total distinct sources to produce epidemiological estimates for 88 risk factors and their associated health outcomes for a total of 631 risk–outcome pairs. Pairs were included on the basis of data-driven determination of a risk–outcome association. Age-sex-location-year-specific estimates were generated at global, regional, and national levels. Our approach followed the comparative risk assessment framework predicated on a causal web of hierarchically organised, potentially combinative, modifiable risks. Relative risks (RRs) of a given outcome occurring as a function of risk factor exposure were estimated separately for each risk–outcome pair, and summary exposure values (SEVs), representing risk-weighted exposure prevalence, and theoretical minimum risk exposure levels (TMRELs) were estimated for each risk factor. These estimates were used to calculate the population attributable fraction (PAF; ie, the proportional change in health risk that would occur if exposure to a risk factor were reduced to the TMREL). The product of PAFs and disease burden associated with a given outcome, measured in disability-adjusted life-years (DALYs), yielded measures of attributable burden (ie, the proportion of total disease burden attributable to a particular risk factor or combination of risk factors). Adjustments for mediation were applied to account for relationships involving risk factors that act indirectly on outcomes via intermediate risks. Attributable burden estimates were stratified by Socio-demographic Index (SDI) quintile and presented as counts, age-standardised rates, and rankings. To complement estimates of RR and attributable burden, newly developed burden of proof risk function (BPRF) methods were applied to yield supplementary, conservative interpretations of risk–outcome associations based on the consistency of underlying evidence, accounting for unexplained heterogeneity between input data from different studies. Estimates reported represent the mean value across 500 draws from the estimate's distribution, with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values across the draws. Findings: Among the specific risk factors analysed for this study, particulate matter air pollution was the leading contributor to the global disease burden in 2021, contributing 8·0% (95% UI 6·7–9·4) of total DALYs, followed by high systolic blood pressure (SBP; 7·8% [6·4–9·2]), smoking (5·7% [4·7–6·8]), low birthweight and short gestation (5·6% [4·8–6·3]), and high fasting plasma glucose (FPG; 5·4% [4·8–6·0]). For younger demographics (ie, those aged 0–4 years and 5–14 years), risks such as low birthweight and short gestation and unsafe water, sanitation, and handwashing (WaSH) were among the leading risk factors, while for older age groups, metabolic risks such as high SBP, high body-mass index (BMI), high FPG, and high LDL cholesterol had a greater impact. From 2000 to 2021, there was an observable shift in global health challenges, marked by a decline in the number of all-age DALYs broadly attributable to behavioural risks (decrease of 20·7% [13·9–27·7]) and environmental and occupational risks (decrease of 22·0% [15·5–28·8]), coupled with a 49·4% (42·3–56·9) increase in DALYs attributable to metabolic risks, all reflecting ageing populations and changing lifestyles on a global scale. Age-standardised global DALY rates attributable to high BMI and high FPG rose considerably (15·7% [9·9–21·7] for high BMI and 7·9% [3·3–12·9] for high FPG) over this period, with exposure to these risks increasing annually at rates of 1·8% (1·6–1·9) for high BMI and 1·3% (1·1–1·5) for high FPG. By contrast, the global risk-attributable burden and exposure to many other risk factors declined, notably for risks such as child growth failure and unsafe water source, with age-standardised attributable DALYs decreasing by 71·5% (64·4–78·8) for child growth failure and 66·3% (60·2–72·0) for unsafe water source. We separated risk factors into three groups according to trajectory over time: those with a decreasing attributable burden, due largely to declining risk exposure (eg, diet high in trans-fat and household air pollution) but also to proportionally smaller child and youth populations (eg, child and maternal malnutrition); those for which the burden increased moderately in spite of declining risk exposure, due largely to population ageing (eg, smoking); and those for which the burden increased considerably due to both increasing risk exposure and population ageing (eg, ambient particulate matter air pollution, high BMI, high FPG, and high SBP). Interpretation: Substantial progress has been made in reducing the global disease burden attributable to a range of risk factors, particularly those related to maternal and child health, WaSH, and household air pollution. Maintaining efforts to minimise the impact of these risk factors, especially in low SDI locations, is necessary to sustain progress. Successes in moderating the smoking-related burden by reducing risk exposure highlight the need to advance policies that reduce exposure to other leading risk factors such as ambient particulate matter air pollution and high SBP. Troubling increases in high FPG, high BMI, and other risk factors related to obesity and metabolic syndrome indicate an urgent need to identify and implement interventions