Development of a dynamic model for estimating the food web transfer of chemicals in small aquatic ecosystems

A dynamic combined fate and food web model was developed to estimate the food web transfer of chemicals in small aquatic ecosystems (i.e. ponds). A novel feature of the modeling approach is that aquatic macrophytes (submerged aquatic vegetation) were included in the fate model and were also a food item in the food web model. The paper aims to investigate whether macrophytes are effective at mitigating chemical exposure and to compare the modeling approach developed here with previous modeling approaches recommended in the European Union (EU) guideline for risk assessment of pesticides. The model was used to estimate bioaccumulation of three hypothetical chemicals of varying hydrophobicity in a pond food web comprising 11 species. Three different macrophyte biomass densities were simulated in the model experiments to determine the influence of macrophytes on fate and bioaccumulation. Macrophytes were shown to have a significant effect on the fate and food web transfer of highly hydrophobic compounds with log K_OW > = 5. Modeled peak concentrations in biota were highest for the scenarios with the lowest macrophyte biomass density. The distribution and food web transfer of the hypothetical compound with the lowest hydrophobicity (log K_OW = 3) was not affected by the inclusion of aquatic macrophytes in the pond environment. For the three different hypothetical chemicals and at all macrophyte biomass densities, the maximum predicted concentrations in the top predator in the food web model were at least one order of magnitude lower than the values estimated using methods suggested in EU guidelines. The EU guideline thus provides a highly conservative estimate of risk. In our opinion, and subject to further model evaluation, a realistic assessment of dynamic food web transfer and risk can be obtained using the model presented here.     

The measurement of just in time wastage for a public housing project in Singapore

Just in time waste data is useful for a number of reasons; these include the ability to streamline operations, the ability to be more responsive to the environment, and the improvement in productivity, quality assurance, scheduling and cost savings. Les informations 'juste a temps' relatives aux pertes de temps et de productivite sont utiles pour plusieurs raisons. Elles offrent notamment la possibilite de rationaliser les operations, de mieux repondre aux besoins du milieu, d'ameliorer la productivite et l'assurance qualite, de renforcer les plannings et de reduire les couts.     

A review of ET measurement techniques for estimating the water requirements of urban landscape vegetation

Increasing urbanisation combined with population growth places greater demands on dwindling water supplies. This is especially the case in arid and semi-arid areas like Australia, which is known as the driest inhabited continent on earth. Sustainable irrigation management necessitates better understanding of water requirements in order to decrease environmental risks and increase water use efficiency. Although the water requirements of agricultural crops are well established in field and laboratory studies, little research has been conducted to investigate the water requirements of urban green spaces. In addition, most previous research investigations have focused on the water requirements of turf grasses and not on other landscape plant species. Landscape plants can include various species of trees, shrubs and turf grasses with different planting densities and microclimates. Such complicated environments make measuring the water requirements of urban landscapes difficult.

This paper reviews previous studies and techniques for measuring the water requirements of urban landscapes and describes how optimum irrigation management strategies for urban landscape vegetation can assist in better water conservation, improved landscape quality and reduced water costs. The authors conclude that WUCOLS is a practical approach that can provide an initial estimate of urban landscape water demand but ideally this should be further refined based on the health and aesthetic condition of the urban vegetation. The authors recommend calibration of the WUCOLS estimates with an in-situ method such as a soil water balance.     

航空配餐楼暖通设计

介绍了航空楼的配餐工艺流程、食品生产流程和温度控制要求,结合三个工程实例着重介绍了航空配餐楼空调系统、通风系统、自控系统设计。     

Method for estimating urban morning mixing height and its distribution in time and space over India

G. C. Holzworth was the first to suggest a method of determining morning mixing heights over an urban area. This method, when applied to some Indian stations could not yield proper results under all circumstances and at all times. These points are thoroughly discussed in this paper. A modified method, which suits well in all seasons and to all stations in India, has been suggested by the present author. Daily urban morning mixing heights are determined based on the modified method and from that mean monthly and seasonal values are evaluated and discussed. During post‐monsoon, winter and summer seasons the heights are very shallow, while they are fairly large during the southwest monsoon season. The coastal regions show greater depths than the inland ones.     

The effect of political unrest on construction time for food grain warehouses in Bangladesh

A range of poorly understood factors affect actual construction time in the context of food sector projects in Bangladesh. One factor of particular interest is political unrest. The data for this study were obtained from a leading design and construction management company in Bangladesh. The sample size consisted of data for 104 food grain warehouse projects scattered all over the country. The effect of political unrest on construction time was analysed in conjunction with other known variables for actual construction time, such as increase in project cost and delay in procurement of construction materials. The effect of local political unrest on construction time was statistically significant even in the presence of project cost and procurement of materials variables. Political unrest could be included in prediction models used for finding out actual construction time of food grain warehouse projects in Bangladesh. Based on these findings, a prediction model for construction time for such projects is developed.     

军用飞机再次出动准备时间仿真预计方法研究

再次出动准备时间是衡量军用飞机作战能力的主要参数,针对如何计算军用飞机再次出动准备时间这一问题,将计划评审技术与仿真技术相结合,提出了基于Stateflow仿真软件的单架飞机再次出动准备时间仿真预计方法,并进行了仿真实例分析。仿真结果表明,该方法能够有效计算再次出动准备时间和关键路径,且具有可视化、流程化和层次化的特点。     

A thermal theory for estimating the flammability limits of a mixture

Because it is difficult to treat the contributions of diluents explicitly using Le Chatelier's rule, a methodology based on thermal balance is proposed for estimating the flammability limits of a mixture. This method converts the flammability information of a mixture into a binary domain of heating/quenching potentials and, after some simple manipulations, converts them back into the flammability domain. The advantage of this conversion is the separation of the heating and quenching potential sums. The dual contribution (heating and quenching) of each species is stressed, while the simplicity of hand calculation is preserved. This method is equivalent to Le Chatelier's rule but has increased flexibility in dealing with various fuel/oxygen/diluents combinations. It will help safety engineers gain more confidence in the hazard analysis of flammable mixtures involving diluents.     

供热系统分时分区控制节能实测分析

针对特殊用途的公共建筑在无人情况下仍照常供暖而造成能源浪费的现状,采用分时分区控制系统对实例工程供热系统进行了节能改造.测试分析了改造后系统的节能量、整体节能效果、不同控制方案对住户温度的影响.结果表明,采用分时分区控制后供热系统节能率高达25.8％,锅炉房总节能8.7％,节能效果显著.     

高空作业平台作业斗称重装置的研究

高空作业车上的作业平台在工作过程中,如果不能准确称量作业斗内的重量,容易造成翻车的重大事故。传统的称重装置无法消除人或物体在斗内不同位置时对称重精度的影响。介绍一种新型称重装置的结构组成和称重原理,该称重装置通过测量碟形弹簧处的受力值,经过计算得出物体的重量,测量值只与两个铰接体的距离有关,不受负载在作业斗中位置的影响,能够准确地称出物体的重量,确保高空作业车的作业安全。     

Application of dynamic time warping to the recognition of mixed equipment activities in cycle time measurement

Analyzing and measuring construction equipment operation are key tasks for managing construction projects. In monitoring construction equipment operation, the cycle-time provides fundamental information. Traditional cycle-time measurement methods have been limited by requiring significant efforts such as additional observers, time, and cost. Thus, this study investigates the feasibility of measuring cycle times by using inertial measurement units (IMUs) embedded in a smartphone. Because the mixed activities of construction equipment involve simultaneous actions of multiple parts, they cause low accuracy in equipment activity classification and cycle-time measurement. To enhance the recognition of these mixed activities and translate the results into reliable cycle time measurements, a dynamic time warping (DTW) algorithm was applied and the DTW distances of IMU signals were used as additional features in activity classification. To test its feasibility, data was collected on-site and the excavator's operation was recorded via IMUs embedded in a smartphone attached to a cabin. Using DTW, the suggested method achieved 91.83% accuracy for cycle-time measurement. This result demonstrates an opportunity to use operators' prevalent mobile devices to measure and report their equipment's cycle times in a cost-effective and continuous manner.     

A critical review of preparation design and workability measurement of concrete material for largescale 3D printing

In recent few years, significant improvement has been made in developing largescale 3D printers to accommodate the need of industrial-scale 3D printing. It is of great feasibility to construct structural components and buildings by means of 3D concrete printing. The major issues of this innovative technique focus on the preparation and optimization of concrete materials which possess favourable printable properties as well as the measurement and evaluation methods of their workability. This paper firstly introduces three largescale 3D printing systems that have been successfully applied in construction industry. It then summarizes the commonly used raw materials in concrete manufacturing. Critical factors that should be particularly controlled in material preparation are specified. Easy-extrusive, easy-flowing, well-buildable, proper setting time and low shrinkage are significant for concrete mixture to meet the critical requirements of a freeform construction process. Thereafter, measuring methods that can be employed to assess the fresh and hardened properties of concrete at early stages are suggested. Finally, a few of evaluation methods are presented which may offer certain assistance for optimizing material preparation. The objective of this work is to review current design methodologies and experimental measurement and evaluation methods for 3D printable concrete materials and promote its responsible use with largescale 3D printing technology.     

MCS在工程估价中的应用

作为一种数值模拟方法,蒙特卡罗模拟已经成功地应用于很多领域,工程估价本身具有不确定性,应用蒙特卡罗模拟来分析工程估价结果的统计特征及风险性,将会成为蒙特卡罗模拟具有现实意义的应用领域。     

A model for estimating radiation received by a person in the landscape

A computer model of physically-based and empirical micro-meteorological equations has been assembled to estimate the total radiation (short and long wave) that would be absorbed by a person in a range of landscapes. This information can be applied to a human thermal comfort model such as COMFA suggested by Brown and Gillespie (1986) to determine the thermal comfort levels in micro-environments. This type of information will aid landscape architects in making climatically-sensitive planning and design decisions.     

液化判别的双曲线模型

基于国内外液化判别方法存在的问题,提出了一个双曲线形式的液化判别新模型。采用中国大陆以往156例液化数据完成了基于标准贯入试验的新公式构造,利用近来集集和阪神地震312例液化新数据进行了检验,并与现有规范方法和Seed方法进行了对比,结果表明：提出的双曲线模型和液化判别公式对不同地震烈度、地下水位和砂层埋深均有较好的适用性;新模型弥补了现有规范Ⅶ度下浅层液化（砂层埋深小于10 m）判别偏于危险的缺欠,对Ⅷ度和Ⅸ度下浅层土液化和非液化场地的成功率比现有规范表现得更为均衡;新模型可满足临界曲线浅层内快速变化、深层时明显变缓的客观实际要求,克服了规范Ⅷ度、Ⅸ度下深层土（砂层埋深10~20 m）判别严重保守的弊端;新模型具有渐近线形式,更符合实际情况,消除了Seed方法中标准贯入临界值随土层埋深增加先递增后递减的不正常现象。     

A method for estimating the sampling variances of multipliers derived from a from-to model

Interindustry models provide a) a simple, logical, and internally consistent way of portraying the interdependent structure of a region and b) an analytic framework which can be used to provide answers to a wide variety of questions. Many of these answers can be expressed as easily understood multipliers, but because the persons for whom these multipliers are most useful possess only limited understanding of the underlying model, they are often forced to accept (or reject) them on faith. In many cases it should be possible to supply these users with some indication of the reliability of estimated multipliers. Many factors affect reliability and these factors are not equally measurable. This paper has the limited objective of estimating that component of multiplier variance induced by the use of sample data to construct the basic model. The procedure adopted exploits a first order approximation technique. It is applied to the data used to construct a from-to model of Oklahoma Planning Region 9. Selected limitations and implications of the resulting estimates are examined.Oklahoma Agricultural Experiment Station Journal Article 2727.     

Evaluation of quantitative real time PCR for the measurement of Helicobacter pylori at low concentrations in drinking water

A rapid DNA extraction and quantitative, real time polymerase chain reaction (QRTPCR) analysis method targeting the ureA gene of Helicobacter pylori was evaluated for the measurement of these organisms on membrane filters at levels that might be expected to be found in drinking water samples. No interference was seen from high levels of background organisms and related, non-target species were detected at approximately 4-5 log(10) lower levels of sensitivity than H. pylori by this assay. A standard curve was generated for the method from analyses of filters containing known numbers of added H. pylori cells. Cell numbers on these filters were determined by staining with a species-specific fluorescent antibody and solid phase cytometry analyses. The mean detection sensitivity of the method was 10 H. pylori cells per filter with a 95% confidence sensitivity of 40 cells and a 95% confidence precision interval of +/-0.57 log(10) based on duplicate analyses of the samples. One liter drinking water samples from several locations in the US were inoculated with the same H. pylori cell suspensions used to generate the standard curve and gave measurements that were consistent with the standard curve suggesting that these sample matrices produced no interference in the method. This method may be useful for the rapid screening of drinking water for H. pylori.     

日常工作的反映

Vilagrasa公司创建于1956年，从那个时候起公司一直注重人及其所处的环境。这就是为什么公司产品的设计无论用在什么场合，都能够迎合使用者以及产品的应用。出于同样的原因，Vilagrasa可以确信它们的产品是受欢迎的，因为它们的产品关注使用者及其所处的环境。     

Application of luminescence for estimating the efficiency of photocatalysts

Capabilities of new approaches in luminescence applications for estimating the quality of photocatalysts have been studied. Since photoluminescent processes are chain ones and initiated by free radicals, luminol and other indicators can be used to determine the efficiency of photocatalysts: the higher is the intensity of luminescent glow, the more is the number of free radicals in the system and the higher is the efficiency of photocatalyst. In some cases, by using special techniques it is possible to study the accumulation of superoxide radicals, hydroxyl radicals, and hydrogen peroxide in the system.