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Economic incentives are widely used to promote green buildings (GB) and consume social resources. However, few studies evaluate the costs and benefits of implementing economic incentives, including hidden costs and benefits. This paper applies cost–benefits analysis (CBA) and transaction cost (TC) theory to systematically evaluate the costs and benefits of implementing the green building economic incentives, with focused study on the Gross Floor Area (GFA) Concession Scheme in Hong Kong. The data of costs and benefits indicate how the GFA Concession Scheme motivates stakeholders and how much it benefits the built environment, which provides a solid foundation for the improvement of the GFA Concession Scheme. Expert interviews were conducted to verify and compliment the new CBA framework and provide empirical evidence for policy-makers and researchers to better understand the allocation of costs and benefits. The results show that the effectiveness of the GFA Concession Scheme is readily justified even if it has caused a lot of extra transaction costs and actual costs. A 10% GFA concession attracts developers to enter the GB market but discourages them to go for a higher level of GB. It is the right time to differentiate the GFA concession to promote a higher level of GB. [ABSTRACT FROM AUTHOR]

A successful extrusion of fiber-reinforced cementitious composites requires a thorough understanding and proper design of the rheological properties of extrudates. The squeeze flow test is regarded as an effective method to evaluate the rheological properties of semi-solid-state fresh extrudates. Based on the strain rates derived from a generalized velocity field, the viscoplastic behavior of cementitious extrudates can be analyzed using the von Mises yield criterion combined with the nonlinear Herschel- Bulkley constitutive relationship. As far as the squeezing force is concerned, the theoretical predictions show good agreement with the experimental measurements. It is found that the bulging phenomenon of a specimen during the squeeze flow process can be depicted by the radial velocity component. Moreover, the velocity field of fresh cementitious extrudates under large plastic deformation is obtained. The present viscoplastic analysis of short fiber-reinforced cementitious extrudates under plastic flow is believed to be a promising mathematical tool toward optimization of formulation for the booming extrusion application. [ABSTRACT FROM AUTHOR]

Accelerated durability assessment is one of the promising ways to provide a sound basis for service life prediction of concrete. To follow the rapid pace of research in modern concrete technology, an effective accelerated assessment system for concrete durability with automatic control and consistent working performance is highly desired. In this paper, the general concepts and ways of implementing computerized feedback control of a multipurpose accelerated concrete durability test system are first presented and applied to frost-resistant (one of the main durability factors of concrete structures in cold regions) assessment of different concretes. The experimental investigations showed that the newly developed automatic feedback controlled system was reliable and had a promising future for the accelerated durability assessment of concretes. Second, based on the premise that the deterioration mechanisms and the surrounding aggressive environment of the concrete under consideration cannot be precisely described by classical logic, it is believed that durability assessment of concrete is indeed a decision-making process and belongs to the fuzzy logic field. Following this line of thought, a general framework of synthetic concrete durability evaluation was developed by combining the principles of various individual accelerated durability tests, such as frost resistance, water permeability, crack width, and carbonation penetration and concepts of fuzzy logic. The working examples showed that the fuzzy synthetic evaluation developed agreed well with the experimental results for concrete durability investigated. [ABSTRACT FROM AUTHOR]

This study formulated a new index for evaluating both the air quality and wind comfort induced by building openings at the pedestrian level of street canyons. The air pollutant concentrations and wind velocities induced by building openings were predicted by a series of CFD simulations using ANSYS Fluent software based on standard k-ɛ model. The types of opening configurations investigated inside isolated and non-isolated canyons included separations, voids and permeable elements. It was found that openings with permeability values of 10% were adequate for improving the air quality and wind comfort conditions for pedestrians after considering the reduction in development floor areas. Openings were effective in improving the air quality in isolated canyons and different types of opening configurations were suggested for different street aspect ratios. On the contrary, openings were not always found effective for non-isolated canyons if there were pollutant sources in adjacent street canyons. As such, it would also be recommended introducing openings to adjacent canyons along with openings to the target canyons. The formulated index can help city planners and building designers to strike an optimal balance between air quality and wind comfort for pedestrians when designing and planning buildings inside urban streets and thus promoting urban environmental sustainability., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Environmental Management System (EMS) has been one of the important tools for sustainable construction for around two decades. However, many issues concerning sustainable development have not been properly addressed, and there is a need for the introduction of green specifications to advance green performance in construction through contract management. This paper defines green specifications, identifies the reasons for adopting green specifications and highlights the environmental issues that may not be addressed by solely adopting EMS. It also presents the results of a recent survey of practitioners concerning their opinions towards green specifications and possible impacts arising from their adoption. From the results of the survey, a framework for developing green specifications is deemed valuable for the cities striving for sustainability. Interestingly, the level of acceptable changes brought about by green specifications as perceived by different industry stakeholders is found to be unrelated to whether they were from organizations implementing EMS or not., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Annoyance has been identified as the most important psychological impact arisen from noise. Besides socioeconomic status, residing neighborhood characteristics such as greenery has been shown to be able to reduce noise annoyance. To study the effects of these potential annoyance modifiers, nine hundred and ninety-two responses were collected through face-to-face interviews via questionnaire surveys. Among them, six-hundred and eighty-eight responses were collected together with adequate dwelling information which enabled a more accurate prediction of home noise levels. All these data were analyzed using an ordered logit model. Results indicate that greenery perception exerts considerable influence on noise annoyance rated at home. Wetland parks and garden parks are shown to be able to reduce noise annoyance to a greater degree than grassy hills. And the effects of the perceived amount of greenery on noise annoyance reduction at home differ according to the setting of greenery to which participant perceived from individual home., (Copyright 2010 Elsevier B.V. All rights reserved.)

Green specifications constitute one of the important elements in green construction. New sustainability requirements and changing priorities in construction management have spurred the emerging green specifications to a faster pace of development. A cross-sectional survey has been conducted in Hong Kong in 2007 to identify principal factors leading to the success of preparing green specifications. Based on extensive construction management literature, 20 variables concerning sustainable construction were summarized. Using the Mann-Whitney U-test, the subtle differences between stakeholders in specifying construction work have been detected even with the high consistency of the responses among the groups. Moreover, five independent factors for successful specification of green construction have been categorized by factor analysis. They are related to (1) green technology and techniques, (2) reliability and quality of specification, (3) leadership and responsibility, (4) stakeholder involvement, and (5) guide and benchmarking systems. Whilst the first and fourth factors are generally more important, different stakeholder groups have different emphases. The results of the survey have been validated against established principles., (2009 Elsevier Ltd. All rights reserved.)

Unlike commercial premises, the indoor air quality of residences is more dynamic, uncontrolled, and prone to human behavioral changes. In consequence, measuring the health benefit gains derived from improving indoor air quality in residences is more complicated. To overcome this, a human thermal comfort model was first integrated with indoor microenvironment models, and subsequently linked with appropriate concentration-response and economic data for estimating the economic benefit gains derived from improving indoor air quality in residences for an adult and an elderly person. In this study, the development of the model is illustrated by using a typical residential apartment locating at the worst air quality neighborhood in Hong Kong and the daily weather profiles between 2002 and 2006. Three types of personal intervention measures were examined in the study: (i) using air cleaner in residence, (ii) changing time spent in residence, and (iii) relocating to a better air quality neighborhood. Our results revealed that employing air cleaners with windows closed in residence throughout the entire year was the most beneficial measure as it could provide the greatest annual health benefit gains. It would give a maximum of HK$2072 in 5-year cumulative benefit gain for an adult and HK$1700 for an elderly person. Employing air cleaners with windows closed in only cool season (October through March) could give the highest marginal return per dollar spent. The benefit gains would become smaller when windows were opened to a greater extent. By contrast, relocating to a better air quality neighborhood and changing the time spent in residence did not appeal to be beneficial intervention measures.

In contrast to a majority of reported damage-cost literature being focused on outdoor pollution, this paper describes the development of a protocol that links population exposure data with reported epidemiological concentration-response coefficients. A change in indoor particulate level is expressed as a change in total exposure levels, which is then linked with a corresponding change in ambient particulate concentrations before evaluating the associated health benefits. In this study, the development of protocol is illustrated by using a typical office building environment and daily time activity patterns of office occupants in Hong Kong. Our results indicate that some benefit gains for the owners-employers and the society would be anticipated if certain filter set configurations had been adopted. However, the amount of benefit gains for the owners-employers is shown to be increased with the average salary level of employees and the duration of their stay in offices.

A voluntary indoor air quality certification scheme has been proposed in Hong Kong for assessing and evaluating the indoor air quality level in a variety of public places like offices, restaurants and pubs. The scheme intends to promote the public well being, however, its technical and financial practicality has led to serious discussions among the government officials, practitioners and premises owners. Accordingly, this study intends to develop a protocol for examining its financial viability by linking the appropriate dose-response and economic data with the results from indoor micro-environment models. The financial viability of the scheme is evaluated by examining the cost and benefit associated with compliance on the different prescribed indoor particulate (PM10) levels. According to our analysis, the indoor action level of 180 microg/m3 as 8-h mean (with the objective of protecting the health of general public) does not require office owners to improve beyond the base setting. Nevertheless, owners should consider altering the base settings in their air conditioning systems so as to secure more benefit on every dollar they spent. On the contrary, the 20 microg/m3 level as 8-h mean (with the objective of providing comfort) is not considered to be financially viable for office owners as they will incur financial loss on compliance. Subsequent sensitivity analysis indicates that the total net benefit derived have a great dependency on the value-of-life estimates used. If conservative health estimates are adopted, the optimum level determined to be beneficial to both owners and the society will be 55 microg/m3, which can be obtained by operating the air conditioning system with a ventilation rate of 10 l/s, primary filters of 80-85% efficiency and secondary filters efficiency of 60-65% arrestance. This information should be extremely valuable for government officials and policy makers in assessing the financial viability of the voluntary indoor assessment scheme.

Objective: To study the injury pattern of children admitted for management of severe trauma or thermal injury., Design: Retrospective review., Setting: Paediatric intensive care unit of a regional hospital, Hong Kong., Patients: Twenty-eight children were admitted under this category from July 1996 to December 1999., Main Outcome Measures: Mechanisms, severity, and circumstances of injury., Results: Road traffic accident was the most common cause of admission, followed by thermal injury, accidental fall, and non-accidental injury. However, children with non-accidental injury were admitted in a significantly more severe condition, as measured by the paediatric risk of mortality score, than those admitted for the other three reasons. Non-accidental injury was also associated with significantly higher morbidity and mortality than the other causes of admission., Conclusions: During the 42-month study period, trauma and thermal injury accounted for 7% of all admissions to the paediatric intensive care unit. Road traffic accident was the most common reason, while non-accidental injury accounted for the most serious injury. Detailed analysis of these cases identified certain preventable risk factors.

Given that Hong Kong is one of the most densely populated cities in the world, the exposure of the Hong Kong people is one of the interesting research areas. In this study, an indirect approach was used to estimate the exposure to nitrogen dioxide (NO2), respiratory dust (PM10) and carbon monoxide (CO) pollutants experienced by different age groups of people in Hong Kong. The average concentrations of the 20 major microenvironments obtained from our measurement survey data, together with the people activity pattern data obtained from 7-day recall questionnaires, were used to predict frequency distributions to exposure assessment. Our results showed that Hong Kong people spent more than 86% of their time indoors. Homes were shown to be the one of the major exposure sites to NO2, CO and PM10 for all age groups. Our results also indicate that the 24-h NO2 exposure for individuals, irrespective of age, spending more than 2 h in commuting daily, was observed to be exceeding the 24-h NO2 exposure standards. This study was one of the pioneering studies with valuable contribution for modeling the estimates of exposures to NO2, PM10 and CO of different age groups in Hong Kong.

We show that D85N/V49A, a mutant bacteriorhodopsin in which two residues, aspartate (D) at position 85 and valine (V) at position 49, have been replaced with asparagine (N) and alanine (A), respectively, has significantly improved optical properties compared with other forms of blue-membrane Bacteriorhodopsin. Absorption studies of the mutant in gels show that it forms the P(490) state at light levels that are comparable with M-state formation in wild-type films. Theoretical calculations based on Kramers-Kronig transformation of light-induced absorption data predict that the refractive index is three times larger than that of mutant D85N. Holographic measurements performed on gelatin-based films confirm that the sensitivity is improved by a factor of 50 over that of D85N.