Soiling of building envelope surfaces and its effect on solar reflectance—Part I: Analysis of roofing product databases

The use of highly reflective “cool” roofing materials can decrease demand for air conditioning, mitigate the urban heat island effect, and potentially slow global warming. However, initially high roof solar reflectance can be degraded by natural soiling and weathering processes. We evaluated solar reflectance losses after three years of natural exposure reported in two separate databases: the Rated Products Directory of the US Cool Roof Rating Council (CRRC) and information reported by manufacturers to the US Environmental Protection Agency (EPA)'s ENERGY STAR^® rating program. Many product ratings were culled because they were duplicative (within a database) or not measured. A second, site-resolved version of the CRRC dataset was created by transcribing from paper records the site-specific measurements of aged solar reflectance in Florida, Arizona and Ohio.Products with high initial solar reflectance tended to lose reflectance, while those with very low initial solar reflectance tended to become more reflective as they aged. Within the site-resolved CRRC database, absolute solar reflectance losses for samples of medium-to-high initial solar reflectance were 2-3 times greater in Florida (hot and humid) than in Arizona (hot and dry); losses in Ohio (temperate but polluted) were intermediate. Disaggregating results by product type—factory-applied coating, field-applied coating, metal, modified bitumen, shingle, single-ply membrane and tile—revealed that absolute solar reflectance losses were largest for field-applied coating, modified bitumen and single-ply membrane products, and smallest for factory-applied coating and metal products.The 2008 Title 24 provisional aged solar reflectance formula overpredicts the measured aged solar reflectance of 0-30% of each product type in the culled public CRRC database. The rate of overprediction was greatest for field-applied coating and single-ply membrane products and least for factory-applied coating, shingle, and metal products. New product-specific formulas of the form ρ_a′=0.20+β(ρ_i−0.20) can be used to estimate provisional aged solar reflectance ρ_a′ from initial solar reflectance ρ_i pending measurement of aged solar reflectance. The appropriate value of soiling resistance β varies by product type and is selected to attain some desired overprediction rate for the formula. The correlations for shingle products presented in this paper should not be used to predict aged solar reflectance or estimate provisional aged solar reflectance because the data set is too small and too limited in range of initial solar reflectance.     

Comparison of measurement methods for quantifying hand force

Hand force is a known risk factor for upper extremity disorders. The objective of the present study was to determine the characteristics of, and the relationships between, exposure assessment methods to quantify hand force. Five methods, used in the laboratory or the field, were used to quantify hand force at three force magnitudes: two direct (or technical) measurement methods, force transducers and electromyography; an observational method; and two self-report approaches, force matching and a visual analogue scale. Five tasks, simulating manual work activities, were performed by 20 participants. The coefficients of variation of measures within and between participants were moderate. All approaches clearly distinguished between the three force levels tested. The reliability of the methods ranged from poor (observation method without information) to good (force transducers method and observation method with information). The measurement methods correlated moderately over all five tasks. Predictions of grip force across all five tasks were poor and even for single tasks the predictions were not much better. The tasks in this study were still simplified; in the field tasks are even more complex and the measurement characteristics might be expected to be less good. A hand force exposure assessment method should therefore be calibrated and tested for each type of hand activity before use.     

Mental strain and the problem of repeated measurements

In the past, stress and strain arising from the execution of mentally demanding tasks have been measured by means of surveys. Such methods require repeated investigation of the individual perceptions and valuations during task fulfilment to record time-dependent changes in strain levels. However, it is possible that the individual measurement procedures employed in surveys-as artefacts-may cause a change in the stress situation and subsequently in the resulting mental strain. The results of the experiments carried out to investigate this hypothesis verify that repeated measurements have a similar effect as a short break. The repeated measurements taken during progressive studies are, therefore, likely to affect the conditions of stress. A change in the level of mental strain recorded can be expected, particularly if the post-test rating is preceded by a long period of low stress before or during which an additional measurement of strain is implemented.     

Assessment of existing steel railway bridges

A series of dynamic tests, acceleration measurements, evaluation, finite element model simulations and safety index calculations were performed on existing steel railway bridges giving service on railway network. Dynamic tests were fulfilled by using a special test train on these bridges to obtain the dynamic parameters and these parameters were then used to refine the finite element models of the bridges. Once the models have been updated to represent the actual condition, safety indices were calculated for structural components of the bridges for each proposed loading condition. These safety indices were used to calculate failure probabilities of structural members. As the final step, system reliability of the bridges was evaluated based on proposed system models of the bridges. It is believed that this study will provide a reliable background for proposed heavier axle loads resulting from new freight trains by realizing the current condition of bridge structures.     

Development of a building performance rating and labelling system in Canada

The recent GBC '98 conference presented the results of a two-year process of developing and testing a new approach to the performance assessment of buildings. The international process is continuing, but in many jurisdictions, including Canada, there is a desire to test the implementation of a system, one that includes ratings and labelling as well as performance assessments. This paper attempts to outline some of the factors that are seen by Natural Resources Canada (NRCan) as relevant to the need, market potential and barriers to such a system. The roles of various actors are considered including industry and government organizations, investors, utilities, building information centres, standards organizations, performance assessors, building owners and operators, tenants. La conference GBC 98 a recemment presente les resultats d'un exercice qui s'est deroule sur deux ans et qui etait consacre a l'elaboration et au test d'une nouvelle methode d'evaluation des performances des batiments. Ce projet se poursuit a l'echelon international mais de nombreux etats, notamment le Canada, souhaitent faire l'essai d'un systeme qui integrerait des notations et des classements ainsi que des evaluations de performances. Cet article tente de mettre en lumiere quelques-uns des facteurs que le ministere canadien des ressources naturelles (NRCan) a juges pertinents par rapport aux besoins, au marche potentiel et aux obstacles qui se dresseraient devant un tel systeme. L'article examine le role des divers acteurs, y compris l'industrie et les organisations officielles, les investisseurs, les services publics, les centres d'information sur le batiment, les organisations de normalisation, les evaluateurs de performances, les proprietaires et les exploitants de batiments, les locataires.     

Rasch-modeling the Portuguese SOCRATES in a clinical sample.

The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES) assesses motivation for treatment in the drug-dependent population. The development of adequate measures of motivation is needed in order to properly understand the role of this construct in rehabilitation. This study probed the psychometric properties of the SOCRATES in the Portuguese population by means of the Rasch Rating Scale Model, which allows the conjoint measurement of items and persons. The participants were 166 substance abusers under treatment for their addiction. Results show that the functioning of the five response categories is not optimal; our re-analysis indicates that a three-category system is the most appropriate one. By using this response category system, both model fit and estimation accuracy are improved. The discussion takes into account other factors such as item format and content in order to make suggestions for the development of better motivation-for-treatment scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

有线电视收视记录器的系统模型和改进

从事收视率调查的从业者都期望能实时掌握最新的收视行为,并由收视率调查信息的反馈来了解或证明该节目或广告的成功与否,作为节目或广告从业人员参考或修正的依据.收视记录器是提供媒体从业人员对收视率调查的测量仪器,它产生准确和客观的收视行为数据.在众多收视率调查方式中,收视行为记录器(People Meter)的测量方式是最客观的量化方式,因此,一部良好的收视行为记录器实时地从收视样本户中取得准确客观的收视行为数据是相当重要的.     

Interaction rules and strategies in psychotherapy.

To examine the presence of interaction rules and strategies used in therapy, the verbal responses of therapists and clients in 26 actual psychotherapy cases were coded using the Interpersonal Communication Rating Scale (ICRS; S. R. Strong, H. Hills, C. Kilmartin, et al., 1988). The conditional response probabilities of these MRS codes were examined from a rules and strategies perspective according to procedures suggested by S. Duncan (1983). The results supported the presence for rules for both the client and the therapist, and these rules were found to involve complementary interactions. No support was found for the presence of strategies in the interactive behavior of either participant. Finally, there was no relation between the presence of rules and session evaluation. The results are discussed with respect to the definition of rules in counseling and the concept of complementarity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Urban and Architectural Sustainability in the Gulf

What is the impact of rapid urbanisation on sustainable development, such as that experienced by cities in the Gulf? Robert Cooke , an Associate Sustainability Consultant at Buro Happold, based in Dubai, seeks to answer this question. He asks what the real contribution might be of the implementation of recent sustainable policies and urban projects, and what more needs to be done to improve the Gulf's ecological footprint and the water-energy nexus.     

江西省水利工程额定管理的思考和探索

就我省水利工程定额管理和造价管理存在的问题及今后的发展进行了说明和探索．