Do ‘green’ buildings have better indoor environments? New evidence

A post-occupancy evaluation (POE) of 12 green and 12 conventional office buildings across Canada and the northern United States was conducted. Occupants (N = 2545) completed an online questionnaire related to environmental satisfaction, job satisfaction and organizational commitment, health and well-being, environmental attitudes, and commuting. In each building on-site physical measurements at a sample of workstations (N= 974) were taken, including: thermal conditions, air quality, acoustics, lighting, workstation size, ceiling height, window access and shading, and surface finishes. Green buildings exhibited superior performance compared with similar conventional buildings. Better outcomes included: environmental satisfaction, satisfaction with thermal conditions, satisfaction with the view to the outside, aesthetic appearance, less disturbance from heating, ventilation and air-conditioning (HVAC) noise, workplace image, night-time sleep quality, mood, physical symptoms, and reduced number of airborne particulates. A variety of physical features led to improved occupant outcomes across all buildings, including: conditions associated with speech privacy, lower background noise levels, higher light levels, greater access to windows, conditions associated with thermal comfort, and fewer airborne particulates. Green building rating systems might benefit from further attention in several areas, including: credits related to acoustic performance, a greater focus on reducing airborne particulates, enhanced support for the interdisciplinary design process and development of POE protocols.

Il a été mené une évaluation après occupation (POE) de 12 immeubles de bureaux verts et 12 immeubles de bureaux classiques répartis à travers le Canada et le nord des Etats-Unis. Les occupants (N?=?2545) ont rempli un questionnaire en ligne portant sur la satisfaction environnementale, la satisfaction au travail et l'implication organisationnelle, la santé et le bien-être, les attitudes environnementales, et les trajets réguliers. Dans chaque immeuble, des mesures physiques in situ sur un échantillon de postes de travail (N?=?974) ont été effectuées, comprenant : les conditions thermiques, la qualité de l'air, l'acoustique, l'éclairage, la taille des postes de travail, la hauteur de plafond, l'accès aux fenêtres et leur occultation, et les finitions de surface. Les bâtiments verts ont affiché des performances supérieures par rapport aux bâtiments classiques similaires. De meilleurs résultats ont été obtenus concernant la satisfaction environnementale, la satisfaction à l'égard des conditions thermiques, la satisfaction à l'égard de la vue sur l'extérieur, l'aspect esthétique, la diminution des perturbations liées aux bruits provenant du chauffage, de la ventilation et de la climatisation (CVC), l'image du lieu de travail, la qualité du sommeil nocturne, l'humeur, les symptômes physiques, et la réduction du nombre de particules en suspension dans l'air. Différentes caractéristiques physiques ont conduit à une amélioration des résultats pour les occupants dans tous les immeubles, concernant notamment les conditions liées à la confidentialité des conversations, les niveaux inférieurs de bruit de fond, les niveaux de luminosité plus élevés, l'accès accru aux fenêtres, les conditions associées au confort thermique, et le nombre moindre de particules en suspension dans l'air. Les systèmes de notation des bâtiments verts pourraient bénéficier d'une plus grande attention apportée à plusieurs domaines, s'agissant en particulier des crédits relatifs aux performances acoustiques, d'un accent accru sur la réduction des particules en suspension dans l'air, d'un soutien renforcé en faveur du processus de conception interdisciplinaire et du développement de protocoles POE.

Mots clés: performances des bâtiments, bilan environnemental, bâtiments verts, environnement intérieur, Leadership in Energy and Environmental Design (LEED), satisfaction des occupants, évaluation après occupation     

中小城市——法国国土开发的催化剂

法国有大量的中小城市,这些城市在1945—1973年间经历了急剧的人口和经济增长。从那以后,中小城市的活力与大聚落的活力就不相上下。半个多世纪以来,小城市发展的重要因素是欧洲的农业政策,中型城市则受益于法国的国土规划政策。然而无论中型城市还是小城市又各自有其内生的发展,主要因为它们提供的良好生活环境可以促进住宅经济发展。法国北方分布较多工业,只要它们懂得创新之道就能抵抗风险;南方以旅游业为主,是全球旅游的胜地。总之,中小城市以它们特有的吸引力为国土的发展做出了贡献。     

Planning in the Ethno-culturally Diverse City: A Comment

This article examines how major retailers, in their attempts to secure sites for very large stores (over 7000 m2 sales area), have had to adopt new strategies in order to overcome resistance from local authority and central government retail planning policy. These strategies include recycling of old retail developments with ‘open A1 consent’, participation in urban regeneration projects and development or redevelopment of ‘district shopping centres’ in urban areas. Discussion of these strategies reveals weaknesses and inconsistencies in retail planning policy in the UK.     

Kinetics of Multi‐Step Redox Processes by Time‐Resolved In Situ X‐ray Diffraction

The kinetics of redox reactions of iron oxide in oxygen carrier 50Fe₂O₃/MgAl₂O₄ are examined using different time‐resolved techniques. Reduction kinetics are studied by H₂ temperature‐programmed reduction (H₂‐TPR) monitored by time‐resolved in situ XRD. In contrast to conventional TPR, in situ XRD distinguishes the three‐stage reduction of Fe₂O₃ → Fe₃O₄ → FeO → Fe. It also shows that the oxidation of Fe → Fe₃O₄ by CO₂ has no intermediate crystalline phases, explaining why its kinetics can easily be investigated by conventional CO₂ temperature‐programmed oxidation (CO₂‐TPO). A shrinking core model which takes into account solid state diffusion allows describing the experimental data.     

A Novel Technology for Natural Gas Conversion by Means of Integrated Oxidative Coupling and Dry Reforming of Methane

A novel process concept for the oxidative coupling of methane followed by the oligomerization to liquids has been developed within the frame of the EU integrated project OCMOL. This technology is based on process intensification principles via cutting‐edge structured microreactor technology. It is also a fully integrated industrial process through the re‐use and the recycling of by‐products, in particular CO₂, at every process stage. The focus of this contribution is on the reaction engineering aspects of the core steps, i.e., catalysts, kinetics and reactor design for the methane coupling and reforming.     

Comparison of Particle Number Counts Measured with an Ink Jet Aerosol Generator and an Aerodynamic Particle Sizer

Aerodynamic particle sizer (APS) users typically calibrate the particle sizing capabilities, but not the counting efficiency upon which aerosol concentration results are based. Herein, comparisons were made between the counts provided by an ink jet aerosol generator (IJAG) with those measured by an APS. Near-monodisperse (geometric standard deviation of about 1.06) liquid or solid aerosols in the size range of 0.95 to 13.3 μm aerodynamic diameter (AD) generated with an IJAG were released into the inner inlet-tube of the APS in a manner that rendered APS wall and aspiration losses negligible. For most experiments, the IJAG generated 75 particles/s, which rate was maintained by the IJAG system through control of electrical pulses applied to its ink jet cartridge. For particles in the size range of 2–13.3 μm AD, the ratio of relative detection efficiency (ratio of the number of particles counted by the APS to the number reported as generated by the IJAG) was 99.3 ± 1.4%; however, for test particles between 0.95 and 2 μm AD, the relative detection efficiency was somewhat lower, but the drop off was less than about 2%. This slight drop off is likely associated with the light scattering detection approach and corresponding counting algorithm of the APS. Tests were conducted where the IJAG produced 7.0 μm AD particles at rates of 1 to 500 s^-1 and the results showed essentially a 1:1 correspondence between IJAG and APS counts. The presence of smaller-sized background particles did not affect the measured APS counts of larger-sized challenge particles.

Copyright 2014 American Association for Aerosol Research     

Impact of the Cd2+ treatment on the electrical properties of Cu2ZnSnSe4 and Cu(In,Ga)Se2 solar cells

The present contribution aims at determining the impact of modifying the properties of the absorber/buffer layer interface on the electrical performance of Cu₂ZnSnSe₄ (CZTSe) thin‐film solar cells, by using a Cd²⁺ partial electrolyte (Cd PE) treatment of the absorber before the buffer layer deposition. In this work, CZTSe/CdS solar cells with and without Cd PE treatment were compared with their respective Cu(In,Ga)Se₂ (CIGSe)/CdS references. The Cd PE treatment was performed in a chemical bath for 7 min at 70 °C using a basic solution of cadmium acetate. X‐ray photoemission spectroscopy measurements have revealed the presence of Cd at the absorber surface after the treatment. The solar cells were characterized using current density–voltage (J–V), external quantum efficiency, and drive‐level capacitance profiling measurements. For the CZTSe‐based devices, the fill factor increased from 57.7% to 64.0% when using the Cd PE treatment, leading to the improvement of the efficiency (η) from 8.3% to 9.0% for the best solar cells. Similar observations were made on the CIGSe solar cell reference. This effect comes from a considerable reduction of the series resistance (R_S) of the dark and light J–V, as determined using the one‐diode model. The crossover effect between dark and light J–V curves is also significantly reduced by Cd PE treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

Performance of Sulfate-reducing Passive Bioreactors for the Removal of Cd and Zn from Mine Drainage in a Cold Climate

Mine Water and the Environment - Passive treatment is a promising, green technology that is increasingly being used for mine drainage treatment. However, several challenges remain concerning its...