Effects of microclimate and human parameters on outdoor thermal sensation in the high-density tropical context of Dhaka

open access articleA thermal comfort questionnaire survey was carried out in the high-density, tropical city Dhaka. Comfort responses from over 1300 subjects were collected at six different sites, alongside meteorological parameters. The effect of personal and psychological parameters was examined in order to develop predictive models. Personal parameters included gender, age, activity, professiontype (indoor or outdoor-based), exposure to air-conditioned space and sweat-levels. Psychological parameters, such as ‘the reason for visiting the place’ and ‘next destination is air-conditioned’, had statistically significant effects on thermal sensation. Other parameters, such as ‘body type’, ‘body exposure to sun’, ‘time living in Dhaka’, ‘travelling in last_30 min’, and ‘hot food’ did not have any significant impact. Respondents’ humidity, wind speed and solar radiation sensation had profound impacts and people were found willing to adjust to the thermal situations with adaptive behaviour. Based on actual sensation votes from the survey, empirical models are developed to predict outdoor thermal sensation in the case study areas. Ordinal linear regression techniques are applied for predicting thermal sensation by considering meteorological and personal conditions of the field survey. The inclusion of personal and weather opinion factors produced an improvement in models based on meteorological factors. The models were compared with the actual thermal sensation using the cross-tabulation technique. The predictivity of the three models (meteorological, thermos-physiological and combined parameter) as expressed by the gamma coefficient were 0.575, 0.636 and 0.727, respectively. In all three models, better predictability was observed in the ‘Slightly Warm’ (71% in meteorological model) and ‘Hot’ (64.9% in combined parameter model) categories—the most important ones in a hot-humid climate

Outdoor thermal comfort and summer PET range: A field study in tropical city Dhaka

© 2019 Elsevier B.V. Urban microclimate has important consequences on the thermal sensation of pedestrians. However, the extent of this effect may vary as other parameters such as respondents’ personal factors, psychological and behavioural aspects and cultural backgrounds may be involved. This heightens the need for subjective assessment and on-site questionnaire surveys alongside objective field measurements to understand outdoor comfort conditions which is essential for creating sustainable urban spaces. In this study thermal comfort conditions outdoors are examined through field surveys in the high-density, tropical city Dhaka, where extensive microclimatic monitoring has been carried out in parallel to subjective responses of the pedestrians. Microclimatic conditions, which are affected by the urban geometry, are found to be statistically correlated with thermal sensation votes (TSV), with air temperature, globe temperature and mean radiant temperature being the most important parameters (correlation coefficients of r = 0.47, 0.45 and 0.44 respectively). The study also reports the effect of urban geometry parameters on microclimatic conditions, identifying strong correlations with globe temperature (r = −0.50), mean radiant temperature (r = −0.48) and wind speed (r = 0.72). Furthermore, the study proposes acceptable ranges (upper limits) for PET for the tropical climate of Dhaka with a ‘Neutral’ range between 29.5° and 32.5 °C confirming that people in outdoor conditions will feel comfortable at a higher PET range.Schlumberger Foundatio

Ruthenium and osmium carbonyl clusters incorporating stannylene and stannyl ligands

The reaction of [Ru₃ (CO)₁₂] with Ph₃SnSPh in refluxing benzene furnished the bimetallic Ru-Sn compound [Ru₃(CO)₈(μ-SPh)₂(μ3-SnPh₂)(SnPh₃)₂] 1 which consists of a SnPh₂ stannylene bonded to three Ru atoms to give a planar tetra-metal core, with two peripheral SnPh₃ ligands. The stannylene ligand forms a very short bond to one Ru atom [Sn-Ru 2.538(1) Å] and very long bonds to the other two [Sn-Ru 3.074(1) Å]. The germanium compound [Ru₃(CO)₈(μ-SPh)₂(μ₃-GePh₂)(GePh₃)₂] 2 was obtained from the reaction of [Ru₃ (CO)₁₂] with Ph₃GeSPh and has a similar structure to that of 1 as evidenced by spectroscopic data. Treatment of [Os₃(CO)₁₀(MeCN)₂] with Ph₃SnSPh in refluxing benzene yielded the bimetallic Os-Sn compound [Os₃(CO)₉(μ-SPh)(μ₃-SnPh₂)(MeCN)(ƞ¹-C₆H₅)] 3. Cluster 3 has a superficially similar planar metal core, but with a different bonding mode with respect to that of 1. The Ph₂Sn group is bonded most closely to Os(2) and Os(3) [2.7862(3) and 2.7476(3) Å respectively] with a significantly longer bond to Os(1), 2.9981(3) Å indicating a weak back-donation to the Sn. The reaction of the bridging dppm compound [Ru₃(CO)₁₀(μ-dppm)] with Ph₃SnSPh afforded [Ru₃(CO)₆(μ-dppm)(μ₃-S)(μ₃-SPh)(SnPh₃)] 5. Compound 5 contains an open triangle of Ru atoms simultaneously capped by a sulfido and a PhS ligand on opposite sides of the cluster with a dppm ligand bridging one of the Ru-Ru edges and a Ph₃Sn group occupying an axial position on the Ru atom not bridged by the dppm ligand

L’effet des outils pédagogiques sur la compréhension spatiale dans l’enseignement des sciences de la santé : une revue systématique

Background: The concept of spatial orientation is integral to health education. Students studying to be healthcare professionals use their visual intelligence to develop 3D mental models from 2D images, like X-rays, MRI, and CT scans, which exerts a heavy cognitive load on them. Innovative teaching tools and technologies are being developed to improve students’ learning experiences. However, the impact of these teaching modalities on spatial understanding is not often evaluated. This systematic review aims to investigate current literature to identify which teaching tools and techniques are intended to improve the 3D sense of students and how these tools impact learners’ spatial understanding. Methods: The preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines were followed for the systematic review. Four databases were searched with multiple search terms. The articles were screened based on inclusion and exclusion criteria and assessed for quality. Results: Nineteen articles were eligible for our systematic review. Teaching tools focused on improving spatial concepts can be grouped into five categories. The review findings reveal that the experimental groups have performed equally well or significantly better in tests and tasks with access to the teaching tool than the control groups. Conclusion: Our review investigated the current literature to identify and categorize teaching tools shown to improve spatial understanding in healthcare professionals. The teaching tools identified in our review showed improvement in measured, and perceived spatial intelligence. However, a wide variation exists among the teaching tools and assessment techniques. We also identified knowledge gaps and future research opportunities.Contexte : Le concept d’orientation spatiale fait partie intégrante de l’enseignement des professions de la santé. Les étudiants qui s’y destinent utilisent leur intelligence visuelle pour se représenter mentalement en 3D des images en 2D comme la radiographie, l’IRM et le tomodensitogramme, ce qui constitue une lourde charge cognitive. On développe actuellement des technologies et des outils pédagogiques innovants pour améliorer l’expérience d’apprentissage des étudiants. Cependant, l’impact de ces ressources pédagogiques sur la compréhension spatiale est rarement évalué. L’objectif de cette revue systématique de la littérature était de recenser les outils et techniques pédagogiques destinés à améliorer la perception 3D des apprenants et d’examiner les effets de ces outils sur leur compréhension spatiale. Méthodes : Suivant les lignes directrices PRISMA (preferred reporting items for systematic reviews and meta-analysis), nous avons consulté quatre bases de données avec des termes de recherche multiples, examiné les articles recensés en fonction de critères d’inclusion et d’exclusion, et évalué leur qualité. Résultats : Dix-neuf articles correspondaient aux critères d’inclusion. Les outils pédagogiques axés sur l’amélioration des concepts spatiaux peuvent être regroupés en cinq catégories. L’examen a révélé que les résultats obtenus par les groupes expérimentaux ayant utilisé l’outil pédagogique pour effectuer les tests et les tâches sont aussi bons ou significativement meilleurs que les résultats obtenus par les groupes témoins. Conclusion : Notre revue de la littérature visant à recenser et catégoriser les outils pédagogiques a montré que ces derniers améliorent la compréhension spatiale, notamment l’intelligence spatiale mesurée et perçue, des professionnels de la santé. Toutefois, il existe une grande variation entre les divers outils pédagogiques et techniques d’évaluation. Nous avons également relevé les lacunes dans les connaissances et les pistes de recherche future

An electron-deficient triosmium cluster containing the thianthrene ligand: Synthesis, structure and reactivity of [Os₃(CO)₉(μ3-η2-C₁₂H₇S₂)(μ-H)]

Reaction of [Os₃(CO)₁₀(CH₃CN)₂] with thianthrene at 80 °C leads to the nonacarbonyl dihydride compound [Os₃(CO)₉(μ-3,4-η²-C₁₂H₆S₂)(μ-H)₂] (1) and the 46-electron monohydride compound [Os₃(CO)₉(μ₃-η²-C₁₂H₇S₂)(μ-H)] (2). Compound 2 reacts reversibly with CO to give the CO adduct [Os₃(CO)₁₀(μ-η²-C₁₂H₇S₂)(μ-H)] (3) whereas with PPh₃ it gives the addition product [Os₃(CO)₉)(PPh₃)(μ-η²-C₁₂H₇S₂)(μ-H)] (4) as well as the substitution product 1,2-[Os₃(CO)₁₀ ((PPh₃)₂] (5) Compound 2 represents a unique example of an electron-deficient triosmium cluster in which the thianthrene ring is bound to cluster by coordination of the sulfur lone pair and a three-center-two-electron bond with the C(2) carbon which bridges the same edge of the triangle as the hydride. Electrochemical and DFT studies which elucidate the electronic properties of 2 are reported

Harmonious accordance of indoor-outdoor thermal comfort and building energy performance by ameliorating urban microclimate in different urban block types in tropical climate

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Open access.This paper explores the effect of outdoor microclimatic environment upon indoor conditions for different urban block types in hot-humid climate. The main focus here is on courtyard patterns, considering its potentials for hot-humid climate is not fully understood yet. Courtyard spaces have been examined in conjunction with the internal spaces of surrounding buildings with the aim to create a link between both. Based on theoretical models, it intends to devise strategies to optimise both indoor-outdoor thermal comfort and building energy performance while enabling the building designers and urban professionals to consider these essential issues at the early design stage. For this study, four simplified archetypal urban arrays are selected, primarily developed by Martin and March. These are: pavilions, enclosed courtyard pavilions, open-square and open-rectangular courtyard pavilions. Firstly, it has observed the microclimatic characteristics of the geometric patterns through a high resolution CFD microclimatic model: ENVI-met. Thermal comfort in the adjacent and enclosed outdoor spaces was assessed against Physiological Equivalent Temperature (PET) index with the aid of Rayman 1.2. Secondly, the energy performance of the surrounding buildings was analysed by IES-VE: a building performance modelling tool. The methodology and results from the current study can be integrated in the future urban planning processes in a high-density warm-humid context

Microstrip Patch Antenna for GPS Application

The study and the design of rectangular microstrip patch antenna for multiband applications are presented in this paper. They can be simulated on antenna design software’s such as High Frequency Simulation Software (HFSS), Advanced Design System Momentum (ADS) and Agilent Vector Network Analyzer (E8361A) where different feeding techniques have been deployed to get the desired results. Two rectangular microstrip patch antennas of frequencies 1.5 GHz and 2.4 GHz are designed and simulated on HFSS

Microstrip Patch Antenna for GPS Application

The study and the design of rectangular microstrip patch antenna for multiband applications are presented in this paper. They can be simulated on antenna design software’s such as High Frequency Simulation Software (HFSS), Advanced Design System Momentum (ADS) and Agilent Vector Network Analyzer (E8361A) where different feeding techniques have been deployed to get the desired results. Two rectangular microstrip patch antennas of frequencies 1.5 GHz and 2.4 GHz are designed and simulated on HFSS

Parental supply of alcohol in childhood and risky drinking in adolescence: Systematic review and meta-analysis

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. Whether parental supply of alcohol affects the likelihood of later adolescent risky drinking remains unclear. We conducted a systematic review and meta-analysis to synthesize findings from longitudinal studies investigating this association. We searched eight electronic databases up to 10 September 2016 for relevant terms and included only original English language peer-reviewed journal articles with a prospective design. Two reviewers independently screened articles, extracted data and assessed risk of bias. Seven articles met inclusion criteria, six of which used analytic methods allowing for meta-analysis. In all seven studies, the follow-up period was ≥12 months and attrition ranged from 3% to 15%. Parental supply of alcohol was associated with subsequent risky drinking (odds ratio = 2.00, 95% confidence interval = 1.72, 2.32); however, there was substantial risk of confounding bias and publication bias. In all studies, measurement of exposure was problematic given the lack of distinction between parental supply of sips of alcohol versus whole drinks. In conclusion, parental supply of alcohol in childhood is associated with an increased likelihood of risky drinking later in adolescence. However, methodological limitations preclude a causal inference. More robust longitudinal studies are needed, with particular attention to distinguishing sips from whole drinks, measurement of likely confounders, and multivariable adjustment