Low-temperature synthesis of large-area CNx nanotube arrays

Well-aligned nitrogen-doped multiwall carbon nanotube arrays have been successfully grown over large areas on quartz and silicon wafers by floating-catalyst chemical vapor deposition at low temperatures (600 degrees C). These nitrogen-including nanotubes, derived from pyridine-ferrocene mixtures, have smaller outer diameters but larger inner diameters compared with carbon nanotubes grown from a xylene-ferrocene mixture under similar conditions. The N-doped nanotubes exhibit bamboo-like structures in the core. Elemental analysis and electron energy loss spectroscopy analysis show that the as-prepared nanotubes contain as much as 2.62 wt.% N, with most of the N concentrated in the inner few shells of the nanotube. Such large-scale arrays of well-aligned N-doped nanotubes on silicon wafers have a current density as high as 23.8 mA/cm2 at an applied electric field of 17 V/micron, which can be further improved by patterning the tubes and coating the silicon substrate with a conductive thin metal film for the fabrication of flat panel displays.     

The impact of continuing care adherence on environmental risks, substance use, and substance-related problems following adolescent residential treatment.

The effectiveness of adolescent treatment to reduce substance use has been demonstrated by a number of different literature reviews, yet longer term outcome studies have suggested that continued alcohol and other drug use is common. Participation in continuing care services and reductions in environmental risk factors (e.g., peer substance use or alcohol or drug use in the home) have both been found to be associated with improved posttreatment substance use. The authors conducted Path analysis to examine the experimental direct effect of the Assertive Continuing Care Protocol (S. H. Godley, M. D. Godley, & M. L. Dennis, 2001) on general continuing care adherence following residential treatment and the protocol's indirect effect (via general continuing care adherence) on social and environmental risk factors, as well as subsequent substance use and substance-related problems. Supporting previous findings, the final model indicates that greater adherence to continuing care is associated with reductions in environmental risk, which in turn is associated with reduced adolescent substance use and substance-related problems 9 months after discharge from residential treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Irradiation of synthetic garnet by heavy ions and α-decay of Cm

Garnet, A₃B₂X₃O₁₂, has a structure that can incorporate actinides. Hence, the susceptibility of the garnet structure to radiation damage has been investigated by comparing the results of self-radiation damage from α-decay of ²⁴⁴Cm and a 1 MeV Kr²⁺ ion irradiation. Gradual amorphization with increasing fluence was observed by X-ray diffraction analysis and in situ transmission electron microscopy. The critical dose, D_c, for an yttrium-aluminum garnet (Y₃Al₅O₁₂) doped with 3 wt.% ²⁴⁴Cm is calculated to be 0.4 displacements per atom (dpa). While the doses obtained by ion irradiation experiments of garnets with different compositions (Y_2.43Nd_0.57)(Al_4.43Si_0.44)O₁₂, (Ca_1.64Ce_0.41Nd_0.42La_0.18Pr_0.18Sm_0.14Gd_0.04)Zr_1.27Fe_3.71O₁₂, and (Ca_1.09Gd_1.23Ce_0.43)Sn_1.16Fe_3.84O₁₂, varied from 0.29 to 0.55 dpa at room temperature. The similarity in the amorphization dose at room temperature and critical temperature of the different garnet compositions suggest that the radiation response for the garnet structure is structurally constrained, rather than sensitive to composition, which is the case for the pyrochlore structure-type.     

Performance Measurement of Training in Engineering Organizations

This work introduces a new training program performance assessment methodology for engineering organizations that is based upon needs assessment, types of training, and training effectiveness measures. The methodology checks whether predefined objectives of a company are identified through a needs assessment. Effectiveness is judged on whether the types of training and coursework content are formulated to fulfill the needs assessment objectives, whether the coursework is available to the proper employees, whether the courses are attended and understood by the employees, and whether the coursework content is utilized in the work place to meet the needs assessment objectives of the company. A case study of three training programs conducted within a public sector engineering organization is included to demonstrate the methodology and evaluate both the three programs and the methodology effectiveness. Conclusions suggest improvements to future training programs for the public sector engineering organization, as well as describe potential enhancements to the effectiveness measures of the methodology that can be recognized through further study of existing training programs.     

Subsurface Flow and Transport in Tidal Wetlands: Marsh Plain Equations

Subsurface flow and salinity patterns in a tidal marsh plain determine the character and health of the wetland ecosystem. The presence of a flow field with both saturated and unsaturated regions requires that the governing equations and the associated equations of state transition smoothly between the two regions. The fluid density in the marsh plain is not constant; it responds to changes in both pressure head and salinity. These considerations lead to the development of the marsh plain equations, the coupled field equations for subsurface flow and salinity transport in the continuous saturated∕unsaturated flow domain of a tidal wetland.     

Comparison of the Halstead Category Test and the revised Category Test: Comment on Russell and Levy.

Russell and Levy recently published an article describing a new shortened version of the Halstead Category Test. They compared their revised Category Test (RCAT) with the Category Test (CAT) and reported it to be highly correlated with and as accurate as the CAT in predicting the presence or absence of brain damage. However, they substantially modified the CAT and claimed the two versions to be comparable without having administered the RCAT to a single person. This comment critiques their revision from a theoretical perspective and additionally questions the methodology reported by the authors to establish the RCAT's validity. We conclude that the Russell and Levy modifications of the CAT make the RCAT a new, different, and as yet unvalidated instrument. Suggestions are offered for future research in the area of modifying the CAT or its scoring system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Uncertainty in biomass supply estimates: Lessons from a Yakama Nation case study

The increasing demand for bioenergy in the United States necessitates detailed case studies of cost and supply to assess its feasibility. We have developed supply curves based on six feedstocks in five counties surrounding the Yakama Nation in central Washington using spatially explicit estimates of supply and transportation cost. The supply curves were used to examine a base case supply for a bioenergy plant, to analyze the effects of land ownership, and examine the impacts of uncertainty in parameters used to determine cost and supply. The results show that existing industries produce the cheapest supply of feedstock as a byproduct of their operations, while supplies harvested specifically for bioenergy are considerably more expensive. Fragmented land ownerships lead to the necessity of cooperation between owners and highlight the importance of a strong anchor supply close to the plant. Lastly, uncertainty in supply and cost parameters leads to larger ranges in available biomass, leading to reluctant investment in large plants.     

Multiwall carbon nanotubes enhance the fatigue performance of physiologically maintained methyl methacrylate-styrene copolymer

The introduction of multiwall carbon nanotube (MWCNT)-polymer composites ushered in fresh opportunities for engineering new materials with high performance capabilities. The nanoscale dimensions and extraordinary properties of MWCNTs directly address the sub-micron damage mechanisms (such as crazing) that culminate during the fatigue failure of most polymers. The large traditional graphite fibers commonly used in composite materials do little to address these microscopic mechanisms of cyclic deformation; thus, MWCNTs offer new promise for improving the fatigue performance of polymer systems where the previous successes of traditional graphite fibers were limited. To test this theory, small amounts (0-10 wt%) of MWCNTs were added to methyl methacrylate-styrene copolymer (MMA-co-Sty), a chief component of commercial bone cement. The resulting nanocomposites were tested to failure in fully reversed tension-compression fatigue in a 37 °C saline environment. Testing at 20 MPa peak stress showed that adding 2 wt% and 5 wt% MWCNTs enhanced the fatigue performance of MMA-co-Sty by 565% and 592%, respectively. These results clearly demonstrate that MWCNTs can substantially enhance the fatigue performance of this polymer. Furthermore, a comparison of these results with the literature shows that MWCNTs are better candidates than traditional graphite fibers for improving the fatigue performance of polymer systems.     

Constructing a literature from case studies: Promise and limitations of the method.

This article responds to "Coaching at the Top: Assisting A Chief Executive and His Team ' (M. M. Krajl, 2001 see record 2001-01213-005) by critiquing the article. It extends the discussion by focusing on the desired characteristics of a case study and how a professional literature can be derived from well constructed case studies. Applying these principles to Krajl's article, the author notes some issues concerning the intervention and preceding assessment, including the choice of the term coaching to describe complex and multifaceted interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

项目管理学派：决策学派和权变学派（下）

决策学派关注的第二个方面是通过项目对信息进行加工处理以减少不确定性，这就产生了阶段门的概念。