Density of nafion exchanged with transition metal complexes and tetramethyl ammonium,ferrous, and hydrogen ions: commercial and recast films

The densities of commercial Nafion 117 and cast Nafion 1100 films were determined by the hydrostatic weighing method for films fully exchanged with hexaammineruthenium(III), tris(2,2' bipyridyl)ruthenium(II), tetramethylammonium, ferrous, and hydrogen ions. Films were pretreated in either water or concentrated nitric acid prior to cation exchange. All densities ranged between 1.65 and 2.19 g/cm3. Excluding the proton-exchanged films, the average density is 1.90 +/- 0.14 g/cm3, well in excess of the 1.58 g/cm3 commonly employed for Nafion. The density of acid-pretreated Nafion 1100 was constant at 1.95 +/- 0.03 g/cm3 for all cations except the proton. A simple, empirical model based on the Coulombic interaction between the intercalated cation and the sulfonate sites of the Nafion characterizes density for the commercial Nafion 117 films. A modified version of the model is appropriate for water-treated Nafion 1100. Water content of the films and implications for characterizing modified electrodes are discussed.     

Strengths, Weaknesses, Opportunities, and Threats for Foreign-Invested Construction Enterprises: A China Study

China has been attracting overseas construction enterprises with its vast expanding business market. The country is further opening its construction market to overseas businesses as the result of its accession to the World Trade Organization in 2001. In line with this development, there are an increasing number of foreign-invested construction enterprises (FICEs) entering into the market. Using Porter’s competitiveness factor analysis method, this paper identifies the FICEs’ strengths, weaknesses, opportunities, and threats in the Chinese construction market. Data used in the analysis stem from multiple sources including statistical reports, literature review, regulations and policies, and interviews with construction professionals. These findings should provide a valuable reference for overseas construction enterprises who are interested in developing business in the Chinese construction market.     

Color from shape from color: a simple formalism with known light sources

Photometric stereo is a well-known technique for recovering surface normals of a surface but requires three or more images of a surface taken under illumination from different directions. At best, one may dispense with the need for multiple images by using colored lights tuned to camera filters. But a less restrictive paradigm is available that uses the orientation-from-color approach, wherein multiple broadband illuminants impinge on a surface simultaneously. In that method, colors for a Lambertian surface lie on an ellipsoid in color space. The method has been applied mainly to single-color objects, with ellipsoid quadratic-form parameters determined from a large number of pixels. However, recently Petrov and Antonova [Color Res. Appl. 21, 97 (1996)] developed an entirely local approach, useful also for multicolored objects with color uniform in each patch. We investigate to what extent a method such as that of Petrov and Antonova can be applied in the ostensibly simpler situation in which the complex lighting environment is known, i.e., a color photometric stereo situation, with all lights in play at once with only a single image to analyze. We find that, assuming a simple model of color formation, we are able to recover the object colors along with surface normals, using only a single image. Because we immerse the object in a known lighting environment, we show that only half of the equations utilized by Petrov and Antonova are actually needed, making the method more stable. Nevertheless, solutions do not exist at every pixel; instead we may determine a best estimate of patch color, using a robust estimator, and then apply that estimate throughout a patch. Results are shown to be quite good compared with ground truth. The simple color model can often be made to hold more exactly by transforming the color space into one corresponding to spectrally sharpened sensors, which are a matrix transform away from the actual camera sensors. In our study the reliability and accuracy of the normal vector and of the surface color recovery algorithm are improved by this straightforward transformation.     

Clinical assessment of attachment patterns and personality disorder in adolescents and adults.

The relevance of attachment theory and research for practice has become increasingly clear. The authors describe a series of studies with 3 aims: (a) to validate measures of attachment for use by clinicians with adolescents and adults, (b) to examine the relation between attachment and personality pathology, and (c) to ascertain whether factor analysis can recover dimensions of attachment reflecting both interpersonal and narrative style. In 3 studies, experienced clinicians provided psychometric data using 1 of 4 attachment questionnaires (2 adolescent and 2 adult samples). Attachment dimensions predicted both personality pathology and developmental experiences in predictable ways. Factor analysis identified 4 dimensions that replicated across adolescent and adult samples on the basis of a combination of interpersonal and narrative indicators: secure, dismissing, preoccupied, and incoherent/disorganized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A toolkit for the incremental implementation of heterogeneous database management systems

The integration of heterogeneous database environments is a difficult and complex task. The A la carte Framework addresses this complexity by providing a reusable and extensible architecture in which a set of heterogeneous database management systems can be integrated. The goal is to support incremental integration of existing database facilities into heterogeneous, interoperative, distributed systems. The Framework addresses the three main issues in heterogeneous systems in tegration. First, it identifies the problems in integrating heterogeneous systems. Second, it identifies the key interfaces and parameters required for autonomous systems to interoperate correctly. Third, it demonstrates an approach to integrating these interfaces in an extensible and incremental way. The A la carte Framework provides a set of reusable, integrating components which integrate the major functional domains, such as transaction management, that could or should be integrated in heterogeneous systems. It also provides a mechanism for capturing key characteristics of the components and constraints which describe how the components can be mixed and interchanged, thereby helping to reduce the complexity of the integration process. Using this framework, we have implemented an experimental, heterogeneous configuration as part of the object management work in the software engineering research consortium, Arcadia.     

Energy absorbing capacities of braced metal tubes

The collapse and energy dissipation characteristics of metal tubes braced with tension members are considered experimentally and load bounding techniques are employed to estimate collapse loads of such tubes. The results are applied in the full scale crash testing of a vehicle impact attenuation device composed of clusters of steel tubes and subjected to high speed roadway collisions.     

A turbulent dispersion model for particles or bubbles

A model for dispersed two-phase flow is derived based on a Boltzmann equation. This model is shown to be compatible with the two-fluid model, and includes the source of dispersion. In this model, dispersion is the result of the correlation of the liquid velocity fluctuations with the number density (perhaps more appropriately, with the trajectories of the individual dispersed units). Using this derived force, and a very simple assumption regarding the correlation of the presence of a dispersed unit and the carrier fluid velocity, a form for this force can be derived. This form gives a force which is proportional to the scalar (dot) product of the fluid Reynolds stress tensor with the gradient of bubble number density. For isotropic turbulence, the force is proportional to the gradient of number density. The constant of proportionality depends on the ratio of the dispersed unit relaxation time to the liquid turbulence time scale.     

Assessing risk for completed suicide in patients with alcohol dependence: Clinicians' views of critical factors.

The assessment of potential for suicide among patients with a diagnosis of alcohol dependence has consistently been a dilemma for clinicians. Specifically, a problem for both clinicians and researchers has been determining what risk factors distinguish patients with suicidal ideation from those that are in danger of completed suicide. Identifying what clinicians who specialize in substance abuse view as critical in the assessment and treatment of suicidal patients is a first step in gaining a greater understanding of suicide risk within an alcoholic population. The views of these clinicians are presented and compared with empirical findings on the subject. (PsycINFO Database Record (c) 2010 APA, all rights reserved)