The unequal clinical profile, quality of life and hospital mortality in patients undergoing aortocoronary bypass in the public and private centers of Catalonia. The CIRCORCA Study

INTRODUCTION AND AIMS: The influence of the type of health care funding and management of hospital centres on hospital mortality in coronary artery bypass surgery (CABG) has not been analyzed in detail. We therefore assessed clinical and quality of life preoperative profiles and in-hospital mortality in public and private patients undergoing coronary bypass surgery in Catalonia. METHODS: Clinical questionnaires, Duke Activity Status Index (DASI) and SF-36 were preoperatively administered to all patients undergoing first coronary bypass surgery without associated procedures in Catalonia between November 1996-June 1997. In-hospital morbidity and mortality were recorded. RESULTS: Predictors of in-hospital death, including DASI, SF-36 and comorbidity scores, were significantly worse in public than in private patients. In-hospital mortality rate was more than ten times greater in public than in private patients (8.2% vs 0.7%; p < 0.001). Multivariate analysis identified private funding of health care, among others, as an independent predictor of in-hospital survival. Non evidence-based indications for surgery were significantly more common in private than in public patients (6% vs 0.7%, p < 0.001). CONCLUSIONS: a) In catalonia, the risk profile of public patients undergoing coronary bypass surgery was significantly higher than that of private patients, accounting, at least in part, for a remarkable mortality difference; b) non evidence-based indications for surgery were more common in private than in public patients; c) these unequal patterns raise questions about the adequacy of care and referral patterns in both private and public sectors.     

A new two-stage curing system: Thiol-ene/epoxy homopolymerization using an allyl terminated hyperbranched polyester as reactive modifier

An allyl terminated hyperbranched polyester (HBP) was added to an epoxy formulation containing a trithiol compound to perform a thiol-ene click reaction. By this procedure a flexible thioether network was formed. The photoirradiation of the reactive mixture, which contained a cationic photoinitiator, converted the thioether network in a multifunctional thermal macroinitiator, capable to initiate the cure of the cycloaliphatic epoxy resin(CE) in a second thermal stage. Depending on the proportion of HBP, thermal or photocuring of the epoxy resin took place in different extent, leading to networks with different structures. The photocuring procedure was followed by FTIR and the thermal second stage by DSC. The materials obtained were characterized by DMTA, TGA and SEM. The addition of HBP-Allyl and the trithiol to the formulation allowed increasing the T_g on comparison with the neat epoxy thermoset. The system proposed constitutes a new two-stage dual photo-thermal curing procedure for cycloaliphatic epoxy resins with a thermal latent character.     

Heat and fluid flow characteristics of liquid sodium flowing past a nuclear fuel element with non-uniform energy generation

The prime objective of the present study is to analyze numerically the steady state fluid flow and heat transfer characteristics of liquid sodium as a coolant flowing past over a rectangular nuclear fuel element having non-uniform volumetric energy generation. Accordingly, employing stream function-vorticity formulation and using finite difference schemes, the equations governing the flow and thermal fields in the coolant are solved simultaneously with energy equation for the fuel element by satisfying the conditions of continuity of temperature and heat flux at the solid–fluid interface. Keeping Prandtl number Pr = 0.005 for liquid sodium as constant, numerical results are presented and discussed for a wide range of aspect ratio A_r, conduction–convection parameter N_cc, total energy generation parameter Q_t and Reynolds number Re_H. It is concluded that the rate of heat dissipation from the fuel element to the coolant is independent of A_r, N_cc and Q_t, whereas it increases in proportion to the increase in Re_H. It is also found that for a given material of the fuel element, there is an upper limiting value of N_cc and Re_H beyond which decrease in coolant temperature is negligibly small.     

Investigation of dimensionless parameters and geometry effects on heat‐transfer characteristics of liquid sodium flowing over a flat plate

To improve the cooling performance of a nuclear fuel element, it is important to appraise the effect of dimensionless parameters and the geometry on heat‐transfer characteristic of sodium flowing over a nuclear fuel element. To fulfill this objective, the effects of geometry, Reynolds number (Re_H), conductivity ratio ( N _cc ), and dimensionless total heat generation parameter ( Q_t) on a two‐dimensional steady flow of liquid coolant flowing over a nuclear fuel element are studied. For this purpose, the stream function‐vorticity formulation method is applied. Full Navier Stokes equations and energy equation for the fluid domain are solved concurrently with conduction equation of fuel element applying finite difference scheme. The pseudotransient form of the vorticity transport and energy equations is solved using the alternating direction implicit method. A line‐by‐line technique is used for other discretized equations. Isotherms are also plotted and studied in detail. From the obtained results it can be concluded that for fixed values of aspect ratio and Re _H there exists a critical value of Q_t and N _cc beyond and below which peak temperature in the fuel element surpasses its tolerable limit. The results can also be applied to minimize the peak temperature in the nuclear fuel element (hot spots).     

Process simulation of hydrogen production by steam reforming of diluted bioethanol solutions: Effect of operating parameters on electrical and thermal cogeneration by using fuel cells

The possibility to exploit diluted bioethanol streams is discussed for hydrogen production by steam reforming. An integrated unit constituted by a steam reformer, a hydrogen purification section with high- and low-temperature water gas shift, a methanator reactor and a fuel cell were simulated to achieve residential size cogeneration of 5 kW electrical power + 5 kW thermal power as target output.Process simulation allowed to investigate the effect of the reformer temperature, of bioethanol concentration and of catalyst loading on the temperature and concentration profiles in the steam reformer. The net power output was also calculated on the basis of 27 different operating conditions.P_electrical output ranging from 3.3 to 6.0 kW were obtained, whereas the total heat output P_{thermal, total} ranged from 3.9 to 7.2 kW. The highest overall energy output corresponded to P_electrical = 4.8 kW, P_{Thermal, FC} = 3.1 kW, P_{heat recovery} = 4.1 kW, for a total 12 kW energy output. This was achieved by feeding a mixture with water/ethanol ratio = 11 (mol/mol), irrespectively of the catalyst mass, and setting the ref split temperature so to have an average temperature of 635 °C in the ESR reactor.     

Diagnosis of avian adenovirus infections using DNA in situ hybridization

Three DNA oligonucleotide probes designated FN-23, FN-48, and FN-96 were evaluated for the diagnosis of aviadenovirus infections by DNA in situ hybridization. Paraffin-embedded tissues were obtained from birds with confirmed adenovirus infection, birds with putative adenovirus infections, and birds with intranuclear inclusions caused by herpesvirus and polyomavirus. In birds with confirmed adenovirus infection, probes FN-23 and FN-96 identified 78% and 72% of diseased individuals, respectively. Only probe FN-48 detected chickens with group II adenovirus infection. In birds with putative adenovirus infection, the DNA probes confirmed aviadenovirus infections in 76% of the population. Probes FN-23, FN-96, and FN-48 detected 85%, 74%, and 18% of adenovirus-infected birds, respectively. None of the DNA probes cross-hybridized with tissues from polyomavirus-infected psittaciform birds or with tissues from a chicken with infectious laryngotracheitis. In contrast, probe FN-23 did cross-hybridize to herpesvirus-infected tissues from two of eight psittaciform birds with Pacheco's parrot disease. Probes FN-48 and FN-96 did not react with these tissues.     

Calorimetric studies of PP/Mater‐Bi blends aged in soil

Blends of polypropylene and a commercial biodegradable additive (Mater‐Bi AF05H) were subjected to a soil burial test for 1 year. The effect of the degradation process on the morphology of the blend was studied by differential scanning calorimetry. The melting and crystallization temperatures, degree of crystallinity, lamellar thickness distribution, and crystallization kinetics were analyzed for both the nondegraded and degraded blends and for the pure components before blending and degradation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3446–3453, 2006     

Study of epoxy and alkyd coatings modified with emeraldine base form of polyaniline

In this work we examine the ability of the emeraldine base form of polyaniline to impart protection against corrosion when it is used as additive of commercial paints. For this purpose, three paints, which are used as primers in marine environments, were checked: two epoxy coatings that differ in the presence or absence of inorganic anticorrosive pigment (zinc) and one alkyd coating. In a first stage, the rheological, structural, thermal and mechanical properties of the three coatings were characterized using viscosity measurements, infrared spectroscopy, thermogravimetric analyses and stress–strain assays, respectively. Furthermore, we observed that the resulting properties were not altered by the addition of a low concentration of polyaniline (0.3%, w/w). Accelerated corrosion tests were performed to compare the degree of protection of both the modified and unmodified paints. The polyaniline did not affect to the protective properties of the epoxy without inorganic anticorrosive pigment nor the alkyd formulations. In opposition, the polyaniline added to the epoxy paint with inorganic anticorrosive pigment induced the formation of a zinc oxide layer, which promoted the corrosion attack.     

Novel thermal curing of cycloaliphatic resins by thiol–epoxy click process with several multifunctional thiols

Novel thermosets were prepared by the base‐catalysed reaction between a cycloaliphatic resin (ECC) and various thiol crosslinkers. 4‐(N,N‐Dimethylaminopyridine) (DMAP) was used as base catalyst for the thiol–epoxy reaction. A commercial tetrathiol (PETMP) and three different thiols synthesized by us, 6SH‐SQ, 3SH‐EU and 3SH‐ISO, were tested. 6SH‐SQ and 3SH‐EU were prepared from vinyl or allyl compounds from renewable resources such as squalene and eugenol, respectively. Thiol 3SH‐ISO was prepared starting from commercially available triallyl isocyanurate. A kinetic study of the mixtures was performed using differential scanning calorimetry. Stoichiometric ECC/thiol/DMAP formulations were cured at 120 °C for 1 h, at 150 °C for 1 h and post‐cured for 30 min at 200 °C. The materials were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and dynamic mechanical thermal analysis. The results revealed that the materials obtained from the synthesized thiols had higher thermal stability and glass transition temperatures than those obtained from the commercial PETMP. In addition, all the materials obtained exhibited very good transparency. This study proves the ability of multifunctional thiols to crosslink cycloaliphatic epoxy resins, leading to more flexible materials than those obtained by cationic homopolymerization of ECC or base‐catalysed ECC–anhydride copolymerization. © 2017 Society of Chemical Industry     

Conjugate conduction-forced convection heat transfer analysis of a rectangular nuclear fuel element with non-uniform volumetric energy generation

The main objective of this paper is to present a comparative study of uniform and non-uniform volumetric energy generation in a rectangular nuclear fuel element washed by upward moving stream of liquid sodium. Employing finite difference schemes, the boundary layer equations governing the flow and thermal fields in the fluid domain are solved simultaneously with two-dimensional energy equation in the solid domain by satisfying the continuity of temperature and heat flux at the solid–fluid interface. Numerical results are presented for a wide range of aspect ratio, A_r, conduction–convection parameter, N_cc, total energy generation parameter, Q_t, and flow Reynolds number, Re_H. It is concluded that for the same total energy generation, a somewhat realistic non-uniform volumetric energy generation puts greater restriction on the thermal power generation as compared to the idealistic uniform volumetric energy generation. Further, it is found that despite the total energy generation being the same for two cases, the non-uniform volumetric energy generation within the fuel element results in considerably higher energy dissipation rate.