ANALYSIS OF FUNGI IN MUSHROOM COMPOST USING PCR AND TGGE OF RIBOSOMAL DNA

Introduction　　 Preparation of a uniform and productive sub-strate forthe growth of Agaricusbisporusis impor-tant in commercial edible mushroom production.The traditional production of synthetic compostforthe growth of Agaricus bisporus consists of an un-controlled outdoor composting process called phase ,followed by an indoor,temperature- controlledprocess called phase . Phase involves a pas-teurisation followed by substrate conditioning,which promotes the selectivity of the compost fo…     

Hedonic modeling of commercial property values: distance decay from the links and nodes of rail and highway infrastructure

Transportation - This study investigates the impacts of positive and negative externalities of highways and light rail on commercial property values in Phoenix, Arizona. We hypothesize that the...     

孔隙介质中含砷聚集物的三维成像

为观测砷沉积导致的孔隙介质内部结构的改变,采用X射线差异微断层扫描技术,扫描从Loa流域获得的河床沉积物和实验室配制的含砷样品,对含砷聚集物在孔隙介质中的分布进行了成像分析.经过图像处理去除图像上的噪点和增强图像中砷的信息,获得了孔隙介质中含砷聚集物的三维数据组;采用Avizo 6和Blob3D等工具,对三维数据组进行重建和可视化.成像显示:大量含砷聚集物沉积在介质孔隙和介质表面;不同尺寸聚集物的形态呈现出明显的多样化特征——小颗粒聚集物趋于球形,大颗粒聚集物则趋于扁平状.研究表明,该技术可在不破坏样品的前提下,实现对孔隙介质沉积前后内部结构变化的直接观测.     

Snowplow Steering Guidance with Gain Stabilization

Acquisition and utilization of lateral guidance information is crucial for steering a vehicle. With practice, drivers can successfully perform the steering function using visual perception and hand-eye coordination. However, this seemingly simple task becomes difficult when the visual information loses its clarity. Driving a snowplow during whiteout conditions is one such example. In order to improve the safety and efficiency of snow removal operations, a supplemental guidance display was proposed and successfully implemented in a California Department of Transportation (Caltrans) snowplow. The guidance information was calculated based on the magnetic markers embedded in the roadway. The crucial step to this success is a transformation of the guidance display problem into a robust driver-in-the-loop control problem. This transformation considers the 'display' law as part of the overall driver-steering-control algorithm. Two key 'assumptions' for this design are (1) the 'display' law should be designed in such a way that drivers can use 'proportional' control gain alone to satisfy the performance and stability requirements of the steering tasks, and (2) the driver steering model can be described as a combination of gain and dynamic delay under the display law in (1). This paper describes the validation process for the 'gain' stabilization design concept as well as the associated driver steering model using the initial snowplow test data.     

Sliding mode observers for vehicle mode detection

This paper explores the use of sliding mode observers to detect the onset of potentially dangerous vehicle modes such as oversteer, understeer or split-μ braking. Provided these modes can be detected quickly enough, existing stability controllers can be engaged to ensure safe performance of the vehicle. It is shown that the equivalent output error injection signals associated with the sliding mode observer have distinctive signatures depending on the particular mode encountered. Appropriate thresholds on these signals can be set so the scheme ignores variations which arise during normal driving, but can detect and isolate different undesirable vehicle modes within 0.3 seconds of their onset.     

A justice-theoretic approach to the distribution of transportation benefits: Implications for transportation planning practice in the United States

Transportation improvements inevitably lead to an uneven distribution of user benefits, in space and by network type (private and public transport). This paper makes a moral argument for what would be a fair distribution of these benefits. The argument follows Walzer’s “Spheres of Justice” approach to define the benefits of transportation, access, as a sphere deserving a separate, non-market driven, distribution. That distribution, we propose, is one where the maximum gap between the lowest and highest accessibility, both by mode and in space, should be limited, while attempting to maximize average access. We then review transportation planning practice for a priori distributional goals and find little explicit guidance in conventional and even justice-oriented transportation planning and analyses. We end with a discussion of the implications for practice.     

Carbon flux in ice–ocean–plankton systems of the Bellingshausen Sea during a period of ice retreat

Most analyses of marine microbial systems in the seasonally ice covered areas of the Southern Ocean have been based on data from the major embayment areas of the Ross and Weddell Seas. In this study data were collected at stations covering a range of regimes from full ice cover through to open water in the Bellingshausen Sea. A major feature of the production system was a rapid retreat of the ice-edge, which uncoupled the marginal ice zone from a phytoplankton bloom which remained associated with a frontal system. This bloom was maintained, and probably initiated, in an unusual environment generated by the interaction between the marginal ice zone and the front. Size-based analyses of the microbial system were derived for ice-covered, recently ice-covered and open water sites. Estimates of standing stocks and key rate processes were combined to produce a single food web network for each station. The under-ice system was one of low production and low recycling but apparently high retention. As the ice retreated the microbial systems to the north began to develop, but these were constrained by grazing pressure. The bloom in the area appeared to be sustained even though estimated losses were far higher than production, although the high sedimentation losses expected were not observed. The carbon flow networks are discussed in relation to the environmental changes and the interaction of the marginal ice zone and the frontal system appears crucial to the phytoplankton. Microzooplankton grazing is implicated as a major controlling factor. The local microbial dynamics are strongly influenced by material which was produced at an earlier time and somewhere else in the Southern Ocean.