Interaction of a phosphorus‐based FR,a nanoclay and PA6. Part 2 interaction of the complete PA6 polymer nanocomposites

Polyamide 6 (PA6) is modified with a nanoclay (NC), Cloisite 30B and/or a flame retardant (FR), OP1311. The thermal decomposition of pure PA6 and PA6 nanocomposites is done by thermogravimetric analysis (TGA). The decomposition products from TGA in nitrogen and air are analysed online by Fourier transform infrared (FTIR) spectroscopy in order to examine the time/temperature‐dependent thermal degradation processes and monitor the evolved gases online. The profiles of the evolved gases are compared with ε‐caprolactam spectra, which are the main species in the gas phase. Results show that the addition of the fire retardant decreases the degradation temperature, whereas the incorporation of NC (PA6+NC) contributes to increased residual mass and char formation. The evolved gases from TGA‐FTIR in nitrogen from pure PA6 and (PA6+NC) are hydrocarbons, carbon dioxide, water, ε‐caprolactam and ammonia. The (PA6+FR) and (PA6+NC+FR) evolve the same volatiles with an additional phosphorus‐containing species, namely diethylphosphinic acid. The thermo‐oxidative degradation of all these composites in air yields carbon monoxide with an increased production of carbon dioxide, water and hydrogen cyanide. Another important result is that the hydrogen cyanide does not increase when the phosphinate FR is used. Copyright © 2009 John Wiley & Sons, Ltd.     

Downscaling a supercritical water loop for experimental studies on system stability

In industry, supercritical water is being used as e.g. separation agent, solvent or coolant due to the unique fluid properties near the critical point. This has lead to the proposal for a nuclear reactor based on supercritical water, operating at a pressure of 25 MPa and bulk temperatures between 280 °C and 500 °C. The large change of the water density in such a reactor may cause the system to become thermal-hydraulically unstable. Numerical as well as experimental investigation of this phenomenon is therefore essential. The rather high pressure, temperatures and power significantly push up the costs of an experimental facility. For this reason, we propose a scaling procedure based on Freon R-23 as the working fluid so that (i) pressure, power and temperatures are significantly reduced and (ii) the physics determining the dynamics of the system are almost completely preserved. Practical issues, such as the onset of deterioration of heat transfer, are touched upon as well.     

Shear capacity of steel plate girders with large web openings, Part I: Modeling and simulations

Numerical simulations are carried out in order to provide data for the development of a design model for the shear capacity of steel girders with web openings, with and without transverse stiffeners and opening reinforcements. The numerical model is designed such that the girder is in a state of pure shear at the opening center. Results are presented in terms of ultimate shear capacity and distribution of transverse web deformations and von Mises stresses. Based on the numerical data, a design model is presented that accounts for the reduction in web shear area, shear buckling of the web and the effect of opening position, vertical stiffeners and opening reinforcements.     

Occurrence of human papillomavirus infection in cervical intraepithelial neoplasia. A retrospective histopathological study of 317 cases treated by laser conization

The aim of the study was to compare the histological outcome of the cone specimens with the diagnoses of the preoperative biopsies, to assess the distribution of histological features consistent with human papillomavirus (HPV) infection and, finally, to analyse the impact of cellular HPV features on classification of cervical intraepithelial neoplasia (CIN). The study comprised a population of 317 women treated for CIN by laser conization during the period 1983-85. A total of 634 cervical specimens (317 preoperative biopsies and their corresponding cones) were studied retrospectively for CIN classification and examined for morphological signs of HPV infection. For presentation of the results, we used a modified terminology for CIN. Low-grade (LG) CIN included borderline lesions and CIN I, while high-grade (HG) CIN included CIN II and CIN III. The blinded histopathological review revealed HG CIN both in the preoperative biopsies and the cones in 71% of the cases. LG CIN or benign lesions were found in the preoperative biopsies and their corresponding cone specimens in 6% of the study population. HPV features were present in 65% of the preoperative biopsies, and were most prevalent in women under 29 years of age (p < 0.001). Thirteen percent of the total biopsy material was downgraded. The downgrading was most prevalent among original CIN II (p = 0.009) and HPV-negative biopsies (p < 0.001). This study demonstrates that CIN lesions are frequently associated with HPV features, which are significantly more prevalent in the youngest women. Concomitant HPV features do not influence the CIN classification.     

Brain metastases of bronchial and breast carcinoma. Differences in metastatic behavior and prognosis

Evaluation of 135 cases with brain metastases from non-small-cell lung cancer (group 1) compared with 51 cases from small-cell lung cancer (group 2) and 56 cases from breast cancer (group 3) showed that the frequency of solitary metastases was significantly higher in group 1 and 3. However, in group 2 lesions without surrounding edema occurred more frequently. The rate of patients with extracerebral metastases was significantly higher in groups 2 and 3. The longest median interval between primary tumor and brain metastases was observed in breast cancer patients. The highest local remission rate was seen in small-cell lung cancer if patients who received whole-brain irradiation of 30 Gy alone were compared (63% vs 45% in group 1 and 52% in group 3). However, with regard to clinical course no significant differences were recorded. Survival of lung cancer cases was similar, whereas breast cancer cases survived significantly longer, both after radiotherapy alone and after surgery plus radiotherapy. This might be caused by differences in the natural course of the two diseases as well as adjuvant treatment modalities like hormone and chemotherapy. In conclusion, because long-term survivors were observed only in the breast cancer group, these patients probably have the highest chance of profiting from a locally aggressive treatment approach.     

Picture perception: Toward a theoretical model.

Describes J. J. Gibson's new theory of picture perception and a program of research within his framework. An analysis of pictorial information is proposed in which a systematic investigation of the structural components of pictures and their varying effects on perception is seen as preliminary to the postulation of hypothetical pick-up mechanisms. The basic components of pictures are described, and literature is reviewed in the problem areas of distorted and impoverished information, observation from the wrong station point, coexisting flatness and depth information, and the ambiguity of the source of a single projection. The feasibility of the Gibsonian enterprise is demonstrated, and further avenues for research into a structural analysis of pictorial information are noted. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Survival after in-hospital cardiopulmonary resuscitation. A meta-analysis

OBJECTIVE: To determine the rates of immediate survival and survival to discharge for adult patients undergoing in-hospital cardiopulmonary resuscitation, and to identify demographic and clinical variables associated with these outcomes. MEASUREMENTS AND MAIN RESULTS: The MEDLARS database of the National Library of Medicine was searched. In addition, the authors' extensive personal files and the bibliography of each identified study were searched for further studies. Two sets of inclusion criteria were used, minimal (any study of adults undergoing in-hospital cardiopulmonary resuscitation) and strict (included only patients from general ward and intensive care units, and adequately defined cardiopulmonary arrest and resuscitation). Each study was independently reviewed and abstracted in a nonblinded fashion by two reviewers. The data abstracted were compared, and any discrepancies were resolved by consensus discussion. For the subset of studies meeting the strict criteria, the overall rate of immediate survival was 40.7% and the rate of survival to discharge was 13.4%. The following variables were associated with failure to survive to discharge: sepsis on the day prior to resuscitation (odds ratio [OR] 31.3; 95% confidence interval [CI] 1.9, 515), metastatic cancer (OR 3.9; 95% CI 1.2, 12. 6), dementia (OR 3.1; 95% CI 1.1, 8.8), African-American race (OR 2. 8; 95% CI 1.4, 5.6), serum creatinine level at a cutpoint of 1.5 mg/dL (OR 2.2; 95% CI 1.2, 3.8), cancer (OR 1.9; 95% CI 1.2, 3.0), coronary artery disease (OR 0.55; 95% CI 0.4, 0.8), and location of resuscitation in the intensive care unit (OR 0.51; 95% CI 0.4, 0.8). CONCLUSIONS: When talking with patients, physicians can describe the overall likelihood of surviving discharge as 1 in 8 for patients who undergo cardiopulmonary resuscitation and 1 in 3 for patients who survive cardiopulmonary resuscitation.     

Relationships between performance and satisfaction under contingent and noncontingent reward systems.

Investigated relationships between performance and satisfaction in 2 samples of female telephone company workers under a contingent (i.e., pay based on piece rates and promotions based on performance) and a noncontingent (i.e., rewards based on seniority) reward system. Performance levels were similar under the 2 systems but were related to satisfaction with the work itself, pay, and promotions for the contingent Ss and to satisfaction with interpersonal factors, pay, and work for the noncontingent Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)