868 resultados para decomposition of a support


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Resumen del póster presentado en Symposium on Renewable Energy and Products from Biomass and Waste, CIUDEN (Cubillos de Sil, León, Spain), 12-13 May 2015

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Thermal decomposition of flexible polyurethane foam (FPUF) was studied under nitrogen and air atmospheres at 550 °C and 850 °C using a laboratory scale reactor to analyse the evolved products. Ammonia, hydrogen cyanide and nitrile compounds were obtained in high yields in pyrolysis at the lower temperature, whereas at 850 °C polycyclic aromatic hydrocarbons (PAHs) and other semivolatile compounds, especially compounds containing nitrogen (benzonitrile, aniline, quinolone and indene) were the most abundant products. Different behaviour was observed in the evolution of polychlorodibenzo-p-dioxins and furans (PCDD/Fs) at 550 °C and 850 °C. At 550 °C, the less chlorinated congeners, mainly PCDF, were more abundant. Contrarily, at 850 °C the most chlorinated PCDD were dominant. In addition, the total yields of PCDD/Fs in the pyrolysis and combustion runs at 850 °C were low and quite similar.

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A systematic investigation of the thermal decomposition of viscoelastic memory foam (VMF) was performed using thermogravimetric analysis (TGA) to obtain the kinetic parameters, and thermogravimetric analysis coupled to Fourier Transformed Infrared Spectrometry (TGA-FTIR) and thermogravimetric analysis coupled to Mass Spectrometry (TGA-MS) to obtain detailed information of evolved products on pyrolysis and oxidative degradations. Two consecutive nth-order reactions were employed to correlate the experimental data from dynamic and isothermal runs performed at three different heating rates (5, 10 and 20 K/min) under an inert atmosphere. On the other hand, for the kinetic study of the oxidative decomposition, the data from combustion (synthetic air) and poor oxygen combustion (N2:O2 = 9:1) runs, at three heating rates and under dynamic and isothermal conditions, were correlated simultaneously. A kinetic model consisting of three consecutive reactions presented a really good correlation in all runs. TGA-FTIR analysis showed that the main gases released during the pyrolysis of VMF were determined as ether and aliphatic hydrocarbons, whereas in combustion apart from the previous gases, aldehydes, amines and CO2 have also been detected as the main gases. These results were confirmed by the TGA-MS.

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The impact of social support on dissonance arousal was investigated from a social identity view of dissonance theory. This perspective is seen as augmenting current conceptualizations of dissonance theory by predicting when normative information will impact on dissonance arousal and by indicating the availability of identity-related strategies of dissonance reduction. An experiment was conducted to induce feelings of hypocrisy under conditions of behavioral support or nonsupport. Group salience was either high or low, or individual identity was emphasized. As predicted, participants with no support from the salient in-group exhibited the greatest need to reduce dissonance through attitude change and reduced levels of group identification. Results were interpreted in terms of self being central to the arousal and reduction of dissonance.

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The purpose of the current study was to access the degree to which the support needs of women with a newly diagnosed, early invasive, primary breast cancer and their families are being met. A random sample of 544 women diagnosed with early breast cancer was recruited to participate in a telephone survey via state and territory cancer registries. Sixteen percent of women reported not receiving enough support during their diagnosis and treatment, and only 65% of these women reported that their families received enough support. The primary sources of support for women and their families were medical practitioners (eg, surgeons, oncologists, and general practitioner) with very few women or family members utilizing mental health professionals. Given the importance of adequate support when being diagnosed and treated for breast cancer, urgent attention needs to be paid to training medical professionals in providing appropriate support and referrals for their patients.

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A parallel computing environment to support optimization of large-scale engineering systems is designed and implemented on Windows-based personal computer networks, using the master-worker model and the Parallel Virtual Machine (PVM). It is involved in decomposition of a large engineering system into a number of smaller subsystems optimized in parallel on worker nodes and coordination of subsystem optimization results on the master node. The environment consists of six functional modules, i.e. the master control, the optimization model generator, the optimizer, the data manager, the monitor, and the post processor. Object-oriented design of these modules is presented. The environment supports steps from the generation of optimization models to the solution and the visualization on networks of computers. User-friendly graphical interfaces make it easy to define the problem, and monitor and steer the optimization process. It has been verified by an example of a large space truss optimization. (C) 2004 Elsevier Ltd. All rights reserved.

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Forearm support during keyboard use has been reported to reduce neck and shoulder muscle activity and discomfort. However, the effect of forearm support on wrist posture has not been examined. The aim of this study was to examine the effect of 3 different postures during keyboard use: forearm support, wrist support and floating. The floating posture (no support) was used as the reference condition. A wrist rest was present in all test conditions. Thirteen participants completed 20 min wordprocessing tasks in each of the test conditions. Electromyography was used to monitor neck, shoulder and forearm muscle activity. Bilateral and overhead video cameras recorded left and right wrist extension, shoulder and elbow flexion and radial and ulnar deviation. The forearm support condition resulted in significantly less ulnar deviation (

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Background: Postnatal breastfeeding support in the form of home visits is difficult to accommodate in regional Australia, where hospitals often deal with harsh economic constraints in a context where they are required to provide services to geographically, dispersed consumers. This study evaluated a predominately telephone-based support service called the Infant Feeding Support Service. Methods: A prospective cohort design was used to compare data for 696 women giving birth in two regional hospitals (one public, one private) and participating in the support service between January and July 2003 with data from a cohort of 625 women who gave birth in those hospitals before the introduction of the support service. Each mother participating in the support service was assigned a lactation consultant. First contact occurred 48 hours after discharge, and approximately it weekly thereafter for 4 it weeks. Breastfeeding duration was measured at 3 months postpartum. Results: For women from the private hospital, the support service improved exclusive breastfeeding duration to 4.5 weeks postpartum, but these improvements were not evident at 3 months postpartum. No effects were observed for mothers from the public hospital. Quantitative and qualitative data demonstrated high levels of client satisfaction with the support service. Conclusions: This small-scale, predominately telephone-based intervention provided significant, although apparently context-sensitive, improvements to exclusive breastfeeding duration.

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Aim. This paper reports a study to examine the effectiveness of a 12-session mutual support group for Chinese families caring for a relative with schizophrenia compared with a psycho-educational group and routine family support services in Hong Kong. Background. Schizophrenia is a disruptive and distressing illness for patients and their families. With the current trend of community care for mental illness, there is evidence that family intervention reduces patient relapse and re-hospitalization, satisfies the health needs of families and enhances their coping capabilities. Methods. A randomized controlled trial was conducted from May 2002 to June 2003 with 96 Chinese families of a relative with schizophrenia selected from two psychiatric outpatient clinics in Hong Kong. Families were randomly assigned to receive mutual support (n = 32), psycho-education (n = 33) or standard care only (n = 31). The interventions were delivered at outpatient clinics over a 6-month period. Pre- and post- (1 week and 6 months) testing took place and families' functioning, mental health service utilization, patients' level of functioning and duration of re-hospitalization were measured. Results. At both post-test periods, family caregivers and patients in the mutual support group reported statistically significant improvements on family and patients' level of functioning, when compared with their counterparts in the psycho-education and standard care groups. Conclusions. The findings support the use of mutual support groups as an effective modality of family intervention in a Chinese population caring for a family member with schizophrenia to improve both family and patient functioning.

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Plant litter and fine roots are important in maintaining soil organic carbon (C) levels as well as for nutrient cycling. The decomposition of surface-placed litter and fine roots of wheat ( Triticum aestivum ), lucerne ( Medicago sativa ), buffel grass ( Cenchrus ciliaris ), and mulga ( Acacia aneura ), placed at 10-cm and 30-cm depths, was studied in the field in a Rhodic Paleustalf. After 2 years, = 60% of mulga roots and twigs remained undecomposed. The rate of decomposition varied from 4.2 year -1 for wheat roots to 0.22 year -1 for mulga twigs, which was significantly correlated with the lignin concentration of both tops and roots. Aryl+O-aryl C concentration, as measured by 13 C nuclear magnetic resonance spectroscopy, was also significantly correlated with the decomposition parameters, although with a lower R 2 value than the lignin concentration. Thus, lignin concentration provides a good predictor of litter and fine root decomposition in the field.

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Objective: To examine adjustment in children of a parent with multiple sclerosis within a stress and coping framework and compare them with those who have 'healthy' parents. Subjects: A total of 193 participants between 10 and 25 years completed questionnaires; 48 youngsters who had a parent with multiple sclerosis and 145 youngsters who reported that they did not have a parent with an illness or disability. Method: A questionnaire survey methodology was used. Variable sets included caregiving context (e.g. additional parental illness, family responsibilities, parental functional impairment, choice in helping), social support (network size, satisfaction), stress appraisal, coping (problem solving, seeking support, acceptance, wishful thinking, denial), and positive (life satisfaction, positive affect, benefits) and negative (distress, health) adjustment outcomes. Results: Caregiving context variables significantly correlated with poorer adjustment in children of a parent with multiple sclerosis included additional parental illness, higher family responsibilities, parental functional impairment and unpredictability of the parent's multiple sclerosis, and less choice in helping. As predicted, better adjustment in children of a parent with multiple sclerosis was related to higher levels of social support, lower stress appraisals, greater reliance on approach coping strategies (problem solving, seeking support and acceptance) and less reliance on avoidant coping (wishful thinking and denial). Compared with children of 'healthy' parents, children of a parent with multiple sclerosis reported greater family responsibilities, less reliance on problem solving and seeking social support coping, higher somatization and lower life satisfaction and positive affect. Conclusions: Findings delineate the key impacts of young caregiving and support a stress and coping model of adjustment in children of a parent with multiple sclerosis.

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Research shows that social support and maternal self-efficacy are inversely related to postpartum depression; however, little is known about the mechanisms by which these variables impact on depressive symptomatology. This study uses path analysis to examine the proposal that maternal self-efficacy mediates the effects of social support on postpartum depressive symptomatology. Primiparous women (n=247) completed questionnaires during their last trimester and then again at 4 weeks' postpartum (n=192). It was hypothesized that higher levels of parental support, partner support, and maternal self-efficacy would be associated with lower levels of depressive symptomatology postpartum and that the relationship between social support and depressive symptomatology would be mediated by maternal self-efficacy. Results indicated that as expected, higher parental support and maternal self-efficacy were associated with lower levels of depressive symptomatology postpartum. Partner support was found to be unrelated to both depressive symptomatology and maternal self-efficacy. Results from the path analysis supported the mediation model. Findings suggest that parental support lowers depressive symptomatology by the enhancement of maternal self-efficacy.

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Mesoporous chromium oxide (Cr2O3) nanocrystals were first synthesized by the thermal decomposition reaction of Cr(NO3)(3)(circle)9H(2)O using citric acid monohydrate (CA) as the mesoporous template agent. The texture and chemistry of chromium oxide nanocrystals were characterized by N-2 adsorption-desorption isotherms, FTIR, X-ray diffraction (XRD), UV-vis, and thermoanalytical methods. It was shown that the hydrate water and CA are the crucial factors in influencing the formation of mesoporous Cr2O3 nanocrystals in the mixture system. The decomposition of CA results in the formation of a mesoporous structure with wormlike pores. The hydrate water of the mixture provides surface hydroxyls that act as binders, making the nanocrystals aggregate. The pore structures and phases of chromium oxide are affected by the ratio of precursor-to-CA, thermal temperature, and time.

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The goal of evidence-based medicine is to uniformly apply evidence gained from scientific research to aspects of clinical practice. In order to achieve this goal, new applications that integrate increasingly disparate health care information resources are required. Access to and provision of evidence must be seamlessly integrated with existing clinical workflow and evidence should be made available where it is most often required - at the point of care. In this paper we address these requirements and outline a concept-based framework that captures the context of a current patient-physician encounter by combining disease and patient-specific information into a logical query mechanism for retrieving relevant evidence from the Cochrane Library. Returned documents are organized by automatically extracting concepts from the evidence-based query to create meaningful clusters of documents which are presented in a manner appropriate for point of care support. The framework is currently being implemented as a prototype software agent that operates within the larger context of a multi-agent application for supporting workflow management of emergency pediatric asthma exacerbations. © 2008 Springer-Verlag Berlin Heidelberg.

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This thesis is primarily concerned with the synthesis and polymerization of 5-methyl-1;3, 2-dioxathiolan-4-one-2-oxide (lactic acid anhydrosulphite (LAAS)) using anionic initiators under various conditions. Poly(lactic acid) is a biodegradable polymer which finds many uses in biomedical applications such as drug-delivery and wound-support systems. For such applications it is desirable to produce polymers having predictable molecular weight distributions and crystallinity, The use of anionic initiators offers a potential route to the creation of living polymers. The synthesis of LAAS was achieved by means of an established route though the procedure was modified to some extent and a new method of purification of the monomer using copper oxides was introduced, Chromatographic purification methods were also examined but found to be ineffective. An unusual impurity was discovered in some syntheses and this was identified by means of 1H and 13C NMR, elemental analysis and GC-MS. Since poly-α-esters having hydroxyl-bearing substituents might be expected to have high equilibrium water contents and hence low surface tension characteristics which might aid bio-compatibility, synthesis of gluconic acid anhydrosulphite was also attempted and the product characterised by 1H and 13C NMR. The kinetics of the decomposition of lactic acid anhydrosulphite by lithium tert-butoxide in nitrobenzene has been examined by means of gas evolution measurements. The kinetics of the reaction with potassium tert-butoxide (and also sec-butyl lithium) in tetrahydrofuran has been studied using calorimetric techniques. LAAS was block co-polymerized with styrene and also with 1,3-butadiene in tetrahydrofuran (in the latter case a statistical co-polymer was also produced).