Estimation of Maximum Liquid Head over Landfill Barriers

To properly design a drainage layer for either landfill leachate collection systems or final covers, the designer must be able to estimate the maximum liquid head over the barrier for any proposed configuration. This paper presents four explicit formulas for estimating the maximum liquid head over an impervious sloping barrier. By means of numeric comparisons, McEnroe’s 1993 method is recommended for design of drainage layers for both bottom liners and final covers. Pipe slope is an important parameter that influences the maximum leachate head on the liner. Different combinations of base grade and pipe slope can directly affect the actual drainage behavior. If the pipe slope is steeper than the base grade, it will make a longer drainage distance and cause a high leachate head on the liner. A method for calculating the maximum liquid head in multilayered drainage media (e.g., geosynthetic and soil) is presented in the paper. The key consideration for this case is to determine the equivalent hydraulic conductivity of the combined drainage media under the phreatic surface under unconfined seepage conditions.     

Real-Time Collision-Free Path Planning for Robots in Configuration Space

Collision-free path planning for an industrial robot in configuration space requires mapping obstacles from robot‘s workspace into its configuration space.In this paper,an approach to real-time collision-free path planning for robots in configuration space is presented.Obstacle mapping is carried out by fundamental obstacles defined in the workspace and their images in the configuration space.In order to avoid dealing with unimportant parts of the configuration space that do not affect searching a collision-free path between starting and goal configurations,we construct a free subspace by slice configuration obstacles.In this free subspace,the collision-free path is determined by the A^* algorithm.Finally,graphical simulations show the effectiveness of the proposed approach.     

The Economic Burden of Anxiety Disorders in Canada.

Concern over the costs of medical conditions has traditionally overshadowed interest in assessing the costs of mental health problems. Recent research, however, indicates that mental disorders impose considerable costs on society and on the sufferer. Most of this research comes from the United States, while little is known about health-care use patterns, impairment, and costs associated with psychological problems in Canada. Given that cost containment has become a priority, it is crucial to examine mental disorders that may exert pressure on Canada's health-care system. Among mental health problems, anxiety disorders have received considerable attention, as they have been shown to be costly. Among the anxiety disorders, generalized anxiety disorder deserves closer examination as it is highly prevalent in the community and in the general medical sector, and has been shown to be disabling, which suggests that this disorder is a potential cost driver. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of a metal detector to detect buried drums in sandy soil

A commercially available metal detector was used to detect buried steel drums, in a variety of patterns, at a site consisting of relatively dry sand. TThis relatively inexpensive (～ $400–$500) instrument could be used to detect buried objects at most hazardous materials dump sites. It remains, how     

Use of a proton precession magnetometer to detect buried drums in sandy soil

A commercially available proton precession magnetometer (PPM) was used to investigate the detection of containers buried in a prescribed manner at a siThe results indicate that the PPM should be able to detect and delineate any typical dump site with predominantly steel (ferromagnetic) drums. In the uThe ease of deployment combined with the reliability, sensitivity and cost-effectiveness makes the PPM surveying a very promising nondestructive testin     

Porous polymer monolith assisted electrospray

Coupling low-flow analytical separation instrumentation such as capillary electrophoresis, capillary electrochromatography, nano-HPLC, and microfluidic-based devices with electrospray ionization mass spectrometry has yielded powerful analytical tools. However, conventional coupling methodologies such as nanospray suffer from limitations including poor conductive coating robustness, constant clogging, complicated fabrication processes, and incompatibility with large flow rate regimes. This study demonstrates that robust nanospray emitters can be fabricated through the formation and utilization of a porous polymer monolith (PPM) at the end of a fused-silica capillary. Stable electrosprays can be produced from capillaries (75-100-microm i.d.) at a variety of flow rates (50-1000 nL/min) without the need to taper the capillaries by etching or pulling. The PPM is photopatterned to be present only near the capillary exit aperture using conditions that generate pore sizes similar to those seen with nanospray tips. The porous nature of the PPM aids in developing a stable electrospray generating a single clearly visible Taylor cone at relatively high flow rates while at low flow rates (<100 nL/min) a mist, presumably from multiple small Taylor cones, develops. The hydrophobic nature of the PPM should limit problems with band broadening associated with droplet spreading at the capillary exit, while the multiple flow paths inherent in the PPM minimize clogging problems associated with conventional nanospray emitters. Total ion current traces for a constant infusion of standard PPG and cytochrome c solutions are very stable with deviations ranging from only 3 to 8%. The PPM-assisted electrospray produces mass spectra with excellent signal-to-noise ratios from only a few femtomoles of material.     

Best of Both Worlds: Synergistically Derived Material Properties via Additive Manufacturing of Nanocomposites

With an exponential rise in the popularity and availability of additive manufacturing (AM), a large focus has been directed toward research in this topic's movement, while trying to distinguish themselves from similar works by simply adding nanomaterials to their process. Though nanomaterials can add impressive properties to nanocomposites (NCs), there are expansive amounts of opportunities that are left unexplored by simply combining AM with NCs without discovering synergistic effects and novel emerging material properties that are not possible by each of these alone. Cooperative, evolving properties of NCs in AM can be investigated at the processing, morphological, and architectural levels. Each of these categories are studied as a function of the amplifying relationship between nanomaterials and AM, with each showing the systematically selected material and method to advance the material performance, explore emergent properties, as well as improve the AM process itself. Innovative, advanced materials are key to faster development cycles in disruptive technologies for bioengineering, defense, and transportation sectors. This is only possible by focusing on synergism and amplification within additive manufacturing of nanocomposites.