DO浓度对SUFR系统同步硝化反硝化的影响

采用螺旋升流式反应器（SUFR）处理生活污水，考察了好氧反应池中DO浓度对其同步硝化反硝化的影响。结果表明，在好氧反应池上部溶解氧浓度为3．0～3．5mg／L时，发生了明显的同步硝化反硝化现象，其对TN的去除量占SUFR系统对TN去除总量的16％左右；好氧反应池中的同步硝化反硝化反应只发生在池的下部，其中、上部只进行了好氧硝化反应；SUFR系统中好氧反应池上部的最佳溶解氧浓度范围为3．0～3．5mg／L，此时系统的硝化和反硝化效果最佳，好氧反应池中的脱氮效果也较好，系统对TN的去除率〉84％。     

Multiple Random Forests Modelling for Urban Water Consumption Forecasting

The precise forecasting of water consumption is the basis in water resources planning and management. However, predicting water consumption fluctuations is complicated, given their non-stationary and non-linear characteristics. In this paper, a multiple random forests model, integrated wavelet transform and random forests regression (W-RFR), is proposed for the prediction of daily urban water consumption in southwest of China. Raw time series were first decomposed into low- and high-frequency parts with discrete wavelet transformation (DWT). The random forests regression (RFR) method was then used for prediction using each subseries. In the process, the input and output constructions of the RFR model were proposed for each subseries on the basis of the delay times and the embedding dimension of the attractor reconstruction computed by the C-C method, respectively. The forecasting values of each subseries were summarized as the final results. Four performance criteria, i.e., correlation coefficient (R), mean absolute percentage error (MAPE), normalized root mean square error (NRMSE) and threshold static (TS), were used to evaluate the forecasting capacity of the W-RFR. The results indicated that the W-RFR can capture the basic dynamics of the daily urban water consumption. The forecasted performance of the proposed approach was also compared with those of models, i.e., the RFR and forward feed neural network (FFNN) models. The results indicated that among the models, the precision of the predictions of the proposed model was greater, which is attributed to good feature extractions from the multi-scale perspective and favorable feature learning performance using the decision trees.     

燃煤锅炉NOx生成数值模拟研究

因锅炉NOx生成受多种因素影响,仅借助现场试验探索NOx的生成规律及其影响因素存在一定的局限性。以410 t/h四角切圆燃煤锅炉为原型,利用Fluent软件建立其流动、燃烧等相关数值模型,利用常规现场试验对数值模型进行验证及修正,使Fluent数值模型的准确性及可靠性得以提高,以此对某些不具备试验条件的影响因素进行了NOx生成特性的模拟研究。结果表明：所建数值模型能够为正确分析燃烧及NOx生成规律提供充分的理论依据,弥补了现场试验方法的不足。     

Physiological condition monitoring of construction workers

Monitoring of workers' physiological conditions can potentially enhance construction workforce productivity, safety, and well-being. Recently, Physiological Status Monitors (PSMs) were validated as an accurate technology to assess physiological conditions during typical sport science and medicine testing procedures (e.g., treadmill and cycle ergometer protocols). However, sport science and medicine testing procedures cannot simulate routine construction worker movements in a comprehensive manner. Thus, this paper investigated the validity of two PSMs by comparing their measurements with gold standard laboratory instruments' measurements at rest and during dynamic activities resembling construction workforce's routine activities. Two physiological parameters such as heart rate and breathing rate were considered. Ten apparently healthy subjects participated in the study. One of the PSMs proved to be a viable technology in assessing construction workers' heart rate (correlation coefficient ≥ 0.74; percentage of differences within ± 11 bpm ≥ 84.8%).     

Applying building information modeling to integrate schedule and cost for establishing construction progress curves

A cost-based progress curve (called S-curve) is often used to control construction project schedules. To establish a progress curve, the costs that are associated with each scheduling activity must be determined. However, the distributions of the quantities (costs) of cost items among various activities are time-consuming to obtain and error-prone, yielding an unreliable S-curve. This work proposes the use of three-dimensional building information model (BIM) objects to integrate schedule and cost by using the powerful BIM for data acquisition and storage. BIM objects are incorporated into a proposed four-step model to establish construction progress curves. The proposed model defines search criteria (cost item, object, floor, and zone) that precisely identify takeoff objects for extracting the quantities of cost items associated with each activity. The BIM uses keynote, assembly code, and family type catalog functions to provide pop-up menus for the efficient identification of cost items that are associated with each object to preventing errors in the manual typing of cost-item names. Finally, this work demonstrates that uploading the cost items and unit prices into cost estimation software in advance is critical to automating cost estimations in BIM.     

Transportation interface facilities design using interactive high-level computer graphics

A prototype pedestrian facilities design system is described. The design system exploits the capabilities of an intelligent high-resolution vector graphics workstation which features a highly interactive computer graphics environment. A summary of historical developments in pedestrian facility design and graphics workstation architecture is presented, followed by a discussion of the stochastic model and interactive computer graphics features utilized by a prototype facilities design system. Potential applications of such a design system are discussed, and promising areas of future development are outlined.     

Potential of solar heat pipe vacuum collectors in the desiccant cooling process: Modelling and experimental results

Desiccant cooling is an alternative technique to vapour compression systems. When thermally driven at moderate temperatures, it can be coupled to solar collectors. The use of flat-plate collectors and air collectors has demonstrated low efficiency in the coupling process and so a low potential of solar energy use in desiccant cooling. In this paper the use of heat pipe vacuum tube (HPVT) collectors in a solar desiccant cooling set up is investigated. First, a model for the collectors is proposed and experimentally validated under various operating conditions. A model of the storage tank taking into account thermal stratification is also validated. The experimentally evaluated efficiency of the HPVT collectors for one operating day varies between 0.6 and 0.7. Finally, simulation of the solar desiccant plant cooling a building is performed for different climates over a summer season. The solar fraction and the overall efficiency of the solar plant are calculated for this period and the potential of the vacuum tube collectors is evaluated for application to the desiccant cooling process.     

Smoke and heat control for fires in large car parks: Lessons learnt from research?

This paper focuses on car park fire safety, more particularly on fire and smoke (and heat) dynamics. The first part deals with the choice of design fire, based on recent full-scale car fire experiments with modern cars and different set-ups. Different aspects of smoke and heat control (SHC) systems are then discussed from the perspective of smoke (and heat) dynamics. The focus is mainly on the effect of horizontal mechanical ventilation, a popular technique, on the smoke and heat generated by the fire source. Some fundamental differences from (longitudinal) mechanical ventilation in tunnels are described. Possible effects of water (sprinklers, water mist or from a fire brigade intervention), as well as some possible routes for further research, are briefly commented.     

A new design of roof-integrated water solar collector for domestic heating and cooling

A new design of roof-integrated water solar collector is presented. It takes advantage of new synergies found between collector and roof. Its main concept is based on the use of water redistribution for changing the roof configuration. This design provides a low-cost system for household heating and cooling that could be even cheaper than conventional roofs with similar thermal qualities, by using fully its configurable property. In this sense, this design could help us to modify the deeply-rooted paradigm of the classic roof.