1,720,955 research outputs found
Environmental design and thermal comfort in urban courtyards within different urban design patterns in Saudi Arabia
No full textUrban open space design and patterns play a vital role in shaping the microclimate of outdoor environments, significantly influencing user comfort and activities. In a harsh arid environment like that of Saudi Arabia, creating high-quality, thermally comfortable outdoor urban spaces is critical. However, studies have highlighted the lack of detailed policies for the environmental planning and design of outdoor urban spaces in Saudi cities, particularly in Makkah, contributing to increased thermal discomfort.
This research investigates the influence of alternative urban design patterns on the microclimate and thermal comfort of outdoor urban spaces in Makkah, as an example of a city in a hot-arid climate region. Using three types of courtyard at Umm Al-Qura University (semi-enclosed, partially-open with a canopy, and fully-enclosed), the study analyzes key urban design parameters, namely, orientation, aspect ratio, tree coverage, and mist system density and examines their impact on air temperature, RH, WS, mean radiant temperature (MRT) and physiological equivalent temperature (PET). Field measurements were conducted during extreme summer and winter conditions, with meteorological data outside the courtyards recorded for 10 days and microclimatic conditions inside each courtyard monitored for 48 hours. Numerical modelling using ENVI-met software was then used to simulate a series of proposed scenarios (seven for orientation, three for aspect ratio, five for tree coverage, and three for misting), which were then assessed against the base case data to identify the most effective options in each case.
The findings reveal that the impact of the design parameters varies by courtyard type. Orientation adjustments had the greatest influence on the fully-enclosed courtyard, where a 135° rotation reduced daily PET by 0.39°C in summer through improved shading. In contrast, the partially-open courtyard benefitted most from orientation changes that enhanced airflow, reducing PET by 0.15°C in winter. Aspect ratio changes were particularly effective in the semi-enclosed courtyard, where increasing the height-to-width ratio to 0.75 H/W lowered PET by 1.08°C in winter and 0.41°C in summer, due to enhanced shading, without significant airflow restriction. The fully-enclosed courtyard and the partially-open courtyard with the structural canopy benefitted more from the lowest aspect ratio (0.25 H/W), as this enhanced airflow and reduced PET. In winter, the most significant PET reduction occurred in the fully-enclosed courtyard with a low aspect ratio (0.25 H/W), achieving a daily PET reduction of 1.34°C, driven by an increase in WS of 0.66 m/s.
Tree coverage was found to provide substantial cooling across all courtyard types, with 30% coverage reducing PET by 2.34°C in summer and 2.78°C in winter in the fully-enclosed courtyard. The semi-enclosed courtyard experienced a PET reduction of 1.46°C in summer, while the partially-open courtyard with the canopy showed more moderate reductions due to the pre-existing shade. High-density mist systems (2-meter intervals) proved most effective in reducing PET during summer, with the semi-enclosed courtyard showing the largest reduction of 7.61°C, followed by the fully-enclosed courtyard at 6.98°C. However, excessive humidity in enclosed spaces during winter required balancing mist density to prevent discomfort.
These findings are used to develop actionable urban design guidelines for architects and urban designers to promote the efficient use of orientation and aspect ratios to optimise shading and airflow and to ensure that tree coverage and mist systems are utilised most effectively. Recommendations for policy-makers are also provided to create a holistic framework to support the use of urban design to enhance outdoor thermal comfort in Makkah. This research therefore contributes to sustainable urban planning in hot-arid climates by offering practical strategies to reduce thermal stress and mitigate rising temperatures caused by climate change. At the local level it offers solutions to create more comfortable outdoor environments in Makkah and in other Saudi cities, aligning with the goals of Saudi Vision 2030. At an international level, the findings will also be of benefit in other regions which experience similar climatic conditions
Environmental design and thermal comfort in urban courtyards within different urban design patterns in Saudi Arabia
No full textUrban open space design and patterns play a vital role in shaping the microclimate of outdoor environments, significantly influencing user comfort and activities. In a harsh arid environment like that of Saudi Arabia, creating high-quality, thermally comfortable outdoor urban spaces is critical. However, studies have highlighted the lack of detailed policies for the environmental planning and design of outdoor urban spaces in Saudi cities, particularly in Makkah, contributing to increased thermal discomfort.
This research investigates the influence of alternative urban design patterns on the microclimate and thermal comfort of outdoor urban spaces in Makkah, as an example of a city in a hot-arid climate region. Using three types of courtyard at Umm Al-Qura University (semi-enclosed, partially-open with a canopy, and fully-enclosed), the study analyzes key urban design parameters, namely, orientation, aspect ratio, tree coverage, and mist system density and examines their impact on air temperature, RH, WS, mean radiant temperature (MRT) and physiological equivalent temperature (PET). Field measurements were conducted during extreme summer and winter conditions, with meteorological data outside the courtyards recorded for 10 days and microclimatic conditions inside each courtyard monitored for 48 hours. Numerical modelling using ENVI-met software was then used to simulate a series of proposed scenarios (seven for orientation, three for aspect ratio, five for tree coverage, and three for misting), which were then assessed against the base case data to identify the most effective options in each case.
The findings reveal that the impact of the design parameters varies by courtyard type. Orientation adjustments had the greatest influence on the fully-enclosed courtyard, where a 135° rotation reduced daily PET by 0.39°C in summer through improved shading. In contrast, the partially-open courtyard benefitted most from orientation changes that enhanced airflow, reducing PET by 0.15°C in winter. Aspect ratio changes were particularly effective in the semi-enclosed courtyard, where increasing the height-to-width ratio to 0.75 H/W lowered PET by 1.08°C in winter and 0.41°C in summer, due to enhanced shading, without significant airflow restriction. The fully-enclosed courtyard and the partially-open courtyard with the structural canopy benefitted more from the lowest aspect ratio (0.25 H/W), as this enhanced airflow and reduced PET. In winter, the most significant PET reduction occurred in the fully-enclosed courtyard with a low aspect ratio (0.25 H/W), achieving a daily PET reduction of 1.34°C, driven by an increase in WS of 0.66 m/s.
Tree coverage was found to provide substantial cooling across all courtyard types, with 30% coverage reducing PET by 2.34°C in summer and 2.78°C in winter in the fully-enclosed courtyard. The semi-enclosed courtyard experienced a PET reduction of 1.46°C in summer, while the partially-open courtyard with the canopy showed more moderate reductions due to the pre-existing shade. High-density mist systems (2-meter intervals) proved most effective in reducing PET during summer, with the semi-enclosed courtyard showing the largest reduction of 7.61°C, followed by the fully-enclosed courtyard at 6.98°C. However, excessive humidity in enclosed spaces during winter required balancing mist density to prevent discomfort.
These findings are used to develop actionable urban design guidelines for architects and urban designers to promote the efficient use of orientation and aspect ratios to optimise shading and airflow and to ensure that tree coverage and mist systems are utilised most effectively. Recommendations for policy-makers are also provided to create a holistic framework to support the use of urban design to enhance outdoor thermal comfort in Makkah. This research therefore contributes to sustainable urban planning in hot-arid climates by offering practical strategies to reduce thermal stress and mitigate rising temperatures caused by climate change. At the local level it offers solutions to create more comfortable outdoor environments in Makkah and in other Saudi cities, aligning with the goals of Saudi Vision 2030. At an international level, the findings will also be of benefit in other regions which experience similar climatic conditions
Full Forcing Weather File
No full textMeteorological data from the weather station, recorded at 30-minute intervals, were used to generate the full forcing weather file for the simulations. Measurements of temperature, humidity, global radiation, and precipitation were taken at 4 meters above ground level, while wind speed and direction were measured at 10 meters. Data covering a total of 20 days — from 23 August to 2 September 2022, and from 26 December 2022 to 5 January 2023 — were used
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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