Enhancement of composite scarf joint interface strength through carbon nanotube reinforcement

It was investigated whether there was a potentially significant improvement to scarf joint bonding that was achieved through the dispersion of carbon nanotubes (CNTs) along the interface of the composite joint. The study examined various factors that might affect CNT-reinforced joint interface strength. Each composite joint consisted of a vinyl-ester matrix base (DERAKANE 510-A) interlaced with a carbon fiber weave (TORAY T700CF). During the curing process, the research explored several variables concerning the CNT application. The testing included single-walled CNTs (SWCNT), and conventional and bamboo-structure multi-walled CNTs (MWCNT) with varying length, purity, and concentration levels along the surface area of the joint interface. This wide array of data demonstrated the effect of CNTs introduction at the joint interface, and provided the ideal type, size, purity level, and concentration level for composite scarf joint bond reinforcement using CNTs. Furthermore, a computational model was developed to predict the strength of the scarf joints. The predicted model agreed well with the experimental data.     

Trust, power and interorganizational information systems: the case of the electronic trading community TransLease

This paper focuses on Cap Gemini’s electronic commerce system, TransLease. TransLease is an interorganizational information system (IOS), which facilitates electronic commerce between motor vehicle leasing and repair companies. During our investigation, the system was used by approximately 1000 repair agents working for seven of the UK’s leading vehicle leasing and contract hire companies. This system was originally developed by AT&T and acquired by Cap Gemini in July 1998. At the time of acquisition, the system was seen as being of high strategic value, although it was also seen as underperforming. This paper reports the results of an action research project, which formed one element of the process by which Cap Gemini investigated the former problem. In the paper, TransLease is described as a complex electronic community, dependent upon the existence of symbiotic relationships. As such, the problems that the system users and developers experienced can be attributed to factors that impeded the mutual benefit accruing from participation in the system. The efficacy of the terms of exchange and the degree to which participants mutually benefit through electronic interaction is determined by the complex interplay of a number of relational and organizational factors. The research therefore illustrates the importance of the ‘soft’ organizational issues in IOS management and development, and suggests a conceptual model of the factors relevant in this case. At the time of this study, TransLease was still in the early stages of its life cycle, having only been available in the marketplace for approximately 18 months. During this time, through recognizing the complex problems and issues detailed in this paper, Cap Gemini accordingly redressed the way in which the system was managed and maintained. TransLease is now seen as having matured into a highly successful example of an IOS – a view reflected by its position as market leader in the industry. As this paper will show, the key to improving the existing service has been the emphasis Cap Gemini now places on managing the ‘soft’ aspects of the electronic community.     

Sex differences in jealousy: Evolutionary mechanism or artifact of measurement?

Two studies are presented that challenge the evidentiary basis for the existence of evolved sex differences in jealousy. In opposition to the evolutionary view, Study 1 demonstrated that a sex difference in jealousy resulting from sexual versus emotional infidelity is observed only when judgments are recorded using a forced-choice response format. On all other measures, no sex differences were found, both men and women reported greater jealousy in response to sexual infidelity. A second study revealed that the sex difference on the forced-choice measure disappeared under conditions of cognitive constraint. These findings suggest that the sex difference used to support the evolutionary view of jealousy likely represents a measurement artifact resulting from a format-induced effortful decision strategy and not an automatic, sex-specific response shaped by evolution. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Radiation protection concepts and quantities for the occupational exposure to cosmic radiation.

For the purposes of dose limitation and dose control, the harm, or detriment, of exposure to radiation is assessed by the quantity effective dose. Effective dose is evaluated by the application of factors to the averaged absorbed dose in the organs and tissues of the body. Radiation monitoring instruments are generally calibrated in terms of the quantity ambient dose equivalent which is defined in a simple spherical phantom. The relationship of these quantities is described. Requirements for the radiation protection of aircraft crew are given in the European Union Council Directive 96/29/EURATOM. There are requirements to assess the exposure of aircraft crew, to inform them of health risks, to reduce higher doses, and to control the dose to the fetus. There are no explicit dose limits, other than a dose objective to be applied to the exposure of the fetus, and no requirements for designation of areas or classification of workers. There are significant differences between the exposure condition of aircraft crew and workers in most other industries where there is occupational exposure to radiation. There are greater ranges of radiation types and energy, and there are different dose distributions and characteristics of the working populations. However, the field intensity is predictable and, with the exception of rare solar events, there is no risk of significant unexpected exposures. Dose assessment is anticipated to be by folding staff roster information with estimates of route doses, since there is little variability of dose rate within an aircraft. Route doses, which may be either an agreed average value for a given airport pairing and aircraft type, or be flight specific, will be closely linked to measured values. Requirements as to the accuracy of dose assessment should be applied which are broadly similar to those used in individual monitoring generally.     

Adult psychological functioning of individuals born with craniofacial anomalies

This study represents an initial investigation into the adult psychological functioning of individuals born with craniofacial disfigurement. A total of 24 men and women born with a craniofacial anomaly completed paper and pencil measures of body image dissatisfaction, self-esteem, quality of life, and experiences of discrimination. An age- and gender-matched control group of 24 non-facially disfigured adults also completed the measures. As expected, craniofacially disfigured adults reported greater dissatisfaction with their facial appearance than did the control group. Craniofacially disfigured adults also reported significantly lower levels of self-esteem and quality of life. Dissatisfaction with facial appearance, self-esteem, and quality of life were related to self-ratings of physical attractiveness. More than one-third of craniofacially disfigured adults (38 percent) reported experiences of discrimination in employment or social settings. Among disfigured adults, psychological functioning was not related to number of surgeries, although the degree of residual facial deformity was related to increased dissatisfaction with facial appearance and greater experiences of discrimination. Results suggest that adults who were born with craniofacial disfigurement, as compared with non-facially disfigured adults, experience greater dissatisfaction with facial appearance and lower self-esteem and quality of life; however, these experiences do not seem to be universal.     

An in vitro tissue culture bilayer model to examine early events in Mycobacterium tuberculosis infection

A tissue culture bilayer system that mimics some aspects of early alveolar infection by Mycobacterium tuberculosis was developed. This model incorporates human lung epithelial type II pneumocyte (A549) (upper chamber) and endothelial cell (lower chamber) layers separated by a microporous membrane. This construction makes it possible to observe and quantify the passage of bacteria through the two layers, to observe the interaction of the bacteria with the various cell types, and to examine the basic mechanisms of immune cell recruitment to the site of infection. After 10(7) organisms were added to the upper chamber we microscopically observed large numbers of bacteria attached to and within the pneumocytes and we determined by viable-cell counting that a small percentage of the inoculum (0.02 to 0.43%) passed through the bilayer into the lower chamber. When peripheral blood mononuclear cells were added to the lower chamber, microscopic examination indicated a migration of the mononuclear cells through the bilayer to the apical surface, where they were seen associated with the mycobacteria on the pneumocytes. The added complexity of the bilayer system offers an opportunity to define more precisely the roles of the various lung cell types in the pathogenesis of early tuberculosis.     

Identification and structural and functional characterization of human enamelysin (MMP-20)

A cDNA encoding a new human matrix metalloproteinase (MMP) has been cloned from RNA prepared from odontoblastic cells. The open reading frame of the cloned cDNA codes for a polypeptide of 483 amino acids and is extensively similar to the sequence of recently described porcine enamelysin, suggesting that the isolated cDNA codes for the human homologue of this enzyme. Human enamelysin (MMP-20) has a domain organization similar to other MMPs, including a signal peptide, a prodomain with the conserved motif PRCGVPD involved in maintaining enzyme latency, a catalytic domain with a Zn-binding site, and a COOH-terminal fragment similar to the sequence of hemopexin. The calculated molecular mass of human enamelysin is about 54 kDa, which is similar to that of collagenases or stromelysins. However, this human MMP lacks a series of structural features distinctive of these subfamilies of MMPs. The full-length human enamelysin cDNA has been expressed in Escherichia coli, and the purified and refolded recombinant protein is able to degrade synthetic peptides used as substrates of MMPs, confirming that human enamelysin belongs to this family of proteases. Furthermore, the recombinant human enamelysin is able to degrade amelogenin, the major protein component of the enamel matrix. On the basis of its degrading activity on amelogenin, and its highly restricted expression to dental tissues, we suggest that human enamelysin plays a central role in the process of tooth enamel formation. Finally, we have found that the human enamelysin gene (MMP-20) maps to chromosome 11q22, clustered to at least seven other members of the MMP gene family.     

APACS: a system for the automatic analysis and classification of conceptual patterns

Many existing inductive learning systems have been developed under the assumption that the learning tasks are performed in a noise-free environment. To cope with most real-world problems, it is important that a learning system be equipped with the capability to handle uncertainty. In this paper, we first identify the various sources of uncertainty that may be encountered in a noisy problem domain. Next, we present a method for the efficient acquisition of classification rules from training instances which may contain inconsistent, incorrect, or missing information. This algorithm consists of three phases: ( i ) the detection of inherent patterns in a set of noisy training data; ( ii ) the construction of classification rules based on these patterns; and ( iii ) the use of these rules to predict the class membership of an object. The method has been implemented in a system known as APACS (automatic pattern analysis and classification system). This system has been tested using both real-life and simulated data, and its performance is found to be superior to many existing systems in terms of efficiency and classification accuracy. Being able to handle uncertainty in the learning process, the proposed algorithm can be employed for applications in real-world problem domains involving noisy data.