Autothermal Reforming of Methane with Integrated CO2 Capture in a Novel Fluidized Bed Membrane Reactor. Part 2 Comparison of Reactor Configurations

The reactor performance of two novel fluidized bed membrane reactor configurations for hydrogen production with integrated CO2 capture by autothermal reforming of methane (experimentally investigated in Part 1) have been compared using a phenomenological reactor model over a wide range of operating conditions (temperature, pressure, H2O/CH4 ratio and membrane area). It was found that the methane combustion configuration (where part of the CH4 is combusted in situ with pure O2) largely outperforms the hydrogen combustion concept (oxidative sweeping combusting part of the permeated H2) at low H2O/CH4 ratios (<2) due to in situ steam production, but gives a slightly lower hydrogen production rate at higher H2O/CH4 ratios due to dilution with combustion products. The CO selectivity was always much lower with the methane combustion configuration. Whether the methane combustion or hydrogen combustion configuration is preferred depends strongly on the economics associated with the H2O/CH4 ratio

Information seeking and reciprocity: A transformational analysis

The motivation to reciprocate is analyzed within the framework of interdependence theory, with focus on the process of transformation of situations. A model of transformation is presented for the motivation to reciprocate and hypotheses regarding allocation behavior and information seeking are derived. The hypotheses are tested in two experiments implementing a game where participants allocate payoff to self and other in a sequential way, with one participant able to gather costly information regarding the other's previous behavior. Individual differences in the motivation to reciprocate are assessed with the Personal Norm of Reciprocity questionnaire. Results show that participants with high motivation to reciprocate seek information regarding other's past behavior, and react to this information as the norm of reciprocity prescribes. Participants with low motivation to reciprocate prefer information regarding the future of the interaction (Study 1), or no information (Study 2), and behave in a more selfish way. Results are discussed with respect of (1) the transformation of situation process, (2) the role of reciprocity as an interpersonal motive, and (3) the validity of the individual differences measure. Copyright © 2003 John Wiley & Sons, Ltd

Looking for a simple Big Five factorial structure in the domain of adjectives.

The Big Five factors structure is currently the benchmark for personality dimensions. In the domain of adjectives, various instruments have been developed to measure the Big Five. In this contribution the authors propose a methodology to find a simple factorial structure and apply this methodology to the domain of Big Five as measured by adjectives. Using data collected on a sample of 337 Ss (mean age 21.69 yrs), a five-factor benchmark structure is proposed derived from the 50 best marker adjectives selected among the adjectives contained in three instruments specifically developed to measure the Big Five (i.e., L. R. Goldberg's 100 adjectives list, IASR-B5, and SACBIF (1992)). They use this common factor structure (or benchmark structure) to investigate the differences and the similarities between the three operationalizations of the Big Five, and to investigate the placements of the full set of adjectives contained in the three instruments. The main features of the proposed methodology and the generalizability of the obtained results are discussed

La implementación del concepto de marketing : un estudio exploratorio en empresas españolas.

Este artículo tiene como objetivo contribuir al conocimiento de un fenómeno escasamente estudiado: la implementación del concepto de marketing. La literatura muestra que este fenómeno organizativo ha sido estudiado solamente con modelos teóricos deterministas que no se han validado empíricamente. Para solucionar este vacío presentamos una investigación exploratoria desarrollada en una muestra de empresas españolas de di versos sectores industriales. Esta investigación se basa en un modelo que permite evaluar las variables organizativas que integran la implementación del concepto de marketing. Las variables estudiadas son: l. La estructuración de la función de marketing, 2. las responsabilidades organizativas asignadas, 3. Las tácticas de marketing desarrolladas por las firmas. Los resultados muestran que la implementación del concepto de marketing es un proceso multidimensional que no impide que en una misma empresa puedan coexistir estructuras y acciones pertenecientes a diferentes etapas evolutivas. Como consecuencia, se invalidan los modelos que señalan la influencia determinista del entorno sobre el proceso de implementación. Los resultados obtenidos permiten a los académicos reorientar sus recomendaciones teóricas pues muestran como se implementa realmente el marketing en las empresas. Para los gerentes, la investigación permite identificar las variables a desarrollar para mantener una orientación de marketing en sus empresas.Implementación; Adopción; Concepto de marketing; Competitividad; Marketing organizacional; Marketing estratégico;

Urinary estrogen metabolites and prostate cancer : a case-control study and meta-analysis

Objective: To investigate prostate cancer (Pca) risk in relation to estrogen metabolism, expressed as urinary 2-hydroxyestrone (2-OHE1), 16α-hydroxyestrone (16α-OHE1) and 2-OHE1 to 16α-OHE1 ratio. Methods: We conducted a case-control study within the Western New York Health Cohort Study (WNYHCS) from 1996 to 2001. From January 2003 through September 2004, we completed the re-call and follow-up of 1092 cohort participants. Cases (n = 26) and controls (n = 110) were matched on age, race and recruitment period according to a 1:4 ratio. We used the unconditional logistic regression to compute crude and adjusted odds ratios (OR) and 95% confident interval (CI) of Pca in relation to 2-OHE1, 16αOHE1 and 2-OHE1 to 16α-OHE1 by tertiles of urine concentrations (stored in a biorepository for an average of 4 years). We identified age, race, education and body mass index as covariates. We also conducted a systematic review of the literature which revealed no additional studies, but we pooled the results from this study with those from a previously conducted case-control study using the DerSimonian-Laird random effects method. Results: We observed a non-significant risk reduction in the highest tertile of 2-OHE1 (OR 0.72, 95% CI 0.25-2.10). Conversely, the odds in the highest tertile of 16α-OHE1 showed a non-significant risk increase (OR 1.76 95% CI 0.62-4.98). There was a suggestion of reduced Pca risk for men in the highest tertile of 2-OHE1 to 16α-OHE1 ratio (OR 0.56, 95% CI 0.19-1.68). The pooled estimates confirmed the association between an increased Pca risk and higher urinary levels of 16α-OHE1 (third vs. first tertile: OR 1.82, 95% CI 1.09-3.05) and the protective effect of a higher 2-OHE 1 to 16α-OHE1 ratio (third vs. first tertile: OR 0.53, 95% CI 0.31-0.90). Conclusion: Our study and the pooled results provide evidence for a differential role of the estrogen hydroxylation pathway in Pca development and encourage further study

A review of implant provision for hypodontia patients within a Scottish referral centre

Background: Implant treatment to replace congenitally missing teeth often involves multidisciplinary input in a secondary care environment. High quality patient care requires an in-depth knowledge of treatment requirements. Aim: This service review aimed to determine treatment needs, efficiency of service and outcomes achieved in hypodontia patients. It also aimed to determine any specific difficulties encountered in service provision, and suggest methods to overcome these. Methods: Hypodontia patients in the Unit of Periodontics of the Scottish referral centre under consideration, who had implant placement and fixed restoration, or review completed over a 31 month period, were included. A standardised data collection form was developed and completed with reference to the patient's clinical record. Information was collected with regard to: the indication for implant treatment and its extent; the need for, complexity and duration of orthodontic treatment; the need for bone grafting and the techniques employed and indicators of implant success. Conclusion: Implant survival and success rates were high for those patients reviewed. Incidence of biological complications compared very favourably with the literature

The electromagnetic calorimeter of the AMS-02 experiment

The electromagnetic calorimeter (ECAL) of the AMS-02 experiment is a 3-dimensional sampling calorimeter, made of lead and scintillating fibers. The detector allows for a high granularity, with 18 samplings in the longitudinal direction, and 72 sampling in the lateral direction. The ECAL primary goal is to measure the energy of cosmic rays up to few TeV, however, thanks to the fine grained structure, it can also provide the separation of positrons from protons, in the GeV to TeV region. A direct measurement of high energy photons with accurate energy and direction determination can also be provided.Comment: Proceedings of SF2A conference 201

Chronic treatment with statins increases the availability of selenium in the antioxidant defence systems of hemodialysis patients.

Project. Oxidative stress (OS) is enhanced in hemodialysis (HD) patients. Lipid peroxidation and oxidative damage to glycids, proteins and nucleic acids are main consequences of OS and are associated to increased cardiovascular risk. Vitamin E and Glutathione Peroxidase (GSH-Px) represent main antioxidant systems in human cells. Selenium (Se), bound to the active sites of GSH-Px, plays a critical role in this antioxidant defense system. Statins are widely used and extensively investigated in the prevention of cardiovascular disease, notably in high-risk subjects. Several studies suggest that statins show antioxidant effects, protecting low-density lipoproteins from oxidation. Aim of our study was to compare serum Se concentration in ESRD patients on maintenance HD and in homogeneous healthy subjects and to investigate whether chronic assumption of statins may interfere with serum Se concentration in HD patients. Procedure. A total of 103 HD patients and 69 healthy subjects were enrolled; HD patients were then divided into patients who were not treated with statins (group A) and patients who assumed statins since six months at least (group B). Serum Se was determined by atomic absorption spectrometry. Results. Serum Se was significantly lower in HD patients of group A compared to healthy subjects (81.65±19.66mcg/L Vs. 96.47±15.62mcg/L, p<0.0040). However, in HD patients who assumed statins serum Se was significantly higher than in HD patients who did not. (111.83±18.82mcg/L Vs. 81.65±19.66mcg/L, p<0.0001). Conclusions. our results suggest that in HD patients chronic assumption of statins is related to a higher availability of active antioxidant agents and to reduced oxidative stress

Direct route from ethanol to pure hydrogen through autothermal reforming in a membrane reactor: Experimental demonstration, reactor modelling and design

This work reports the integration of thin (∼3–4 μm thick) Pd-based membranes for H2 separation in a fluidized bed catalytic reactor for ethanol auto-thermal reforming. The performance of a fluidized bed membrane reactor has been investigated from an experimental and numerical point of view. The demonstration of the technology has been carried out over 50 h under reactive conditions using 5 thin Pd-based alumina-supported membranes and a 3 wt%Pt-10 wt%Ni catalyst deposited on a mixed CeO2/SiO2 support. The results have confirmed the feasibility of the concept, in particular the capacity to reach a hydrogen recovery factor up to 70%, while the operation at different fluidization regimes, oxygen-to-ethanol and steam-to-ethanol ratios, feed pressures and reactor temperatures have been studied. The most critical part of the system is the sealing of the membranes, where most of the gas leakage was detected. A fluidized bed membrane reactor model for ethanol reforming has been developed and validated with the obtained experimental results. The model has been subsequently used to design a small reactor unit for domestic use, showing that 0.45 m2 membrane area is needed to produce the amount of H2 required for a 5 kWe PEM fuel-cell based micro-CHP system.The presented work is funded within the FluidCELL project as part of the European Union's Seventh Framework Programme (FP7/ 2007-2013) for the Fuel Cells and Hydrogen Joint Technology Initiative under grant agreement nº 621196