Alternativas de ultimação de resíduo plástico termofixo

In the present work it was developed originals alternatives of enveronmentally safe and economically viable destination of thermoset plastic residue from a button factory, which at presnte stores such residue tempor and in a way that is inconvenient to the atmosphere, a waiting safe solutions. As the residue is not recycleab and its burning leberates strongly aggressive gases, safe alternatives were researched. Inicially, ghe residue in incineration was performed in cement ovens with precise control ofe emission of gases, but it was proved inviable due to its low calorific power, as well as the liberation of free lead in the ashes. An original and feasible option was the residue confinemente in soil-ciment blocks, lohich resulted in blocks highly resistant to simple compression with structural block, and also a significant increase in thermal resistence. Was got up other options of original and important composites as: making of blocks for pré-moulded flagstone, internal coating of walls with plaster being obtained good texture results, replenish of ceramic blocks and blocks with cement, also implying in increase of thermal resistance. Besides these original and scientific contributions, the it was technologically contribution of defreadation with suggestions of the material using torch of thermal plasm; for this was projected, built, characterized and tested a torch to it shapes it being obtained exciting results for the development of this technology come back for ending destruction from all the types of inconvenient garbage to the atmosphere

Alternativas de ultimação de resíduo plástico termofixo

In the present work it was developed originals alternatives of enveronmentally safe and economically viable destination of thermoset plastic residue from a button factory, which at presnte stores such residue tempor and in a way that is inconvenient to the atmosphere, a waiting safe solutions. As the residue is not recycleab and its burning leberates strongly aggressive gases, safe alternatives were researched. Inicially, ghe residue in incineration was performed in cement ovens with precise control ofe emission of gases, but it was proved inviable due to its low calorific power, as well as the liberation of free lead in the ashes. An original and feasible option was the residue confinemente in soil-ciment blocks, lohich resulted in blocks highly resistant to simple compression with structural block, and also a significant increase in thermal resistence. Was got up other options of original and important composites as: making of blocks for pré-moulded flagstone, internal coating of walls with plaster being obtained good texture results, replenish of ceramic blocks and blocks with cement, also implying in increase of thermal resistance. Besides these original and scientific contributions, the it was technologically contribution of defreadation with suggestions of the material using torch of thermal plasm; for this was projected, built, characterized and tested a torch to it shapes it being obtained exciting results for the development of this technology come back for ending destruction from all the types of inconvenient garbage to the atmosphere

Arc Root Attachment on the Anode Surface of Arc Plasma Torch Observed with a Novel Method

The arc-root attachment on the anode surface of a dc non-transferred arc plasma torch has been successfully observed using a novel approach. A specially designed copper mirror with a boron nitride film coated on its surface central-region is employed to avoid the effect of intensive light emitted from the arc column upon the observation of weakly luminous arc root. It is found that the arc-root attachment is diffusive on the anode surface of the argon plasma torch, while constricted arc roots often occur when hydrogen or nitrogen is added into argon as the plasma-forming gas.

Arc Root Motions In An Argon-Hydrogen Direct-Current Plasma Torch At Reduced Pressure

Arc root motions in generating dc argon-hydrogen plasma at reduced pressure are optically observed using a high-speed video camera. The time resolved angular position of the arc root attachment point is measured and analysed. The arc root movement is characterized as a chaotic and jumping motion along the circular direction on the anode surface.

Arc Root Motion In An Argon-Hydrogen Dc Plasma Torch

Arc root motion on the anode surface of a dc non-transferred plasma torch was observed. Adding hydrogen changes the arc root attachment from a diffused type to a constricted type, and the arc root of Ar-H-2 plasma suddenly,jumps from one spot to another irregularly. Images of the arc root motions taken by a high-speed video camera are presented.

Modeling of a Laminar DC Arc Plasma Torch

In recent years, stable and long laminarplasma jets have been successfully generated, and thus it is possible to achieve low-noise working surroundings, better process repeatability and controllability, and reduced metal-oxidation degree in plasma materials processing. With such a recent development in thermal plasma science and technology as the main research background, modeling studies are performed concerning the DCarcplasmatorch for generating the long laminar argon plasma jet. Two different two-dimensional modeling approaches are employed to deal with the arc-root attachment at the anode surface. The first approach is based on circumferentially uniform arc-root attachment, while the second uses the so-called fictitious anode method. Modeling results show that the highest temperature and maximum axial-velocity at the plasmatorch exit are ～15000 K and ～1100 m/s, respectively, for the case with arc current of 160 A and argon flow rate of 1.95×10{sup}(-4)kg/s.

Modelling Study On The Plasma Flow and Heat Transfer In A Laminar Arc Plasma Torch Operating At Atmospheric and Reduced Pressure

A modelling study is performed to investigate the characteristics of both plasma flow and heat transfer of a laminar non-transferred arc argon plasma torch operated at atmospheric and reduced pressure. It is found that the calculated flow fields and temperature distributions are quite similar for both cases at a chamber pressure of 1.0 atm and 0.1 atm. A fully developed flow regime could be achieved in the arc constrictor-tube between the cathode and the anode of the plasma torch at 1.0 atm for all the flow rates covered in this study. However the flow field could not reach the fully developed regime at 0.1 atm with a higher flow rate. The arc-root is always attached to the torch anode surface near the upstream end of the anode, i.e. the abruptly expanded part of the torch channel, which is in consistence with experimental observation. The surrounding gas would be entrained from the torch exit into the torch interior due to a comparatively large inner diameter of the anode channel compared to that of the arc constrictor-tube.

Instabilities in a non-transferred direct current plasma torch operated at reduced pressure

Using an oscilloscope, a high-speed video camera and a double-electrostatic probe system, the periodicity and amplitude of the fluctuations in arc voltage, jet luminance and ion saturation current of a plasma jet were monitored to investigate various sources of instabilities and their effects in a non-transferred dc plasma torch operated at reduced pressure. The results show that besides a 300 Hz main fluctuation inherited from the power supply, arc voltage fluctuation of 3–4 kHz with an amplitude less than 5% of the mean voltage was mainly affected by the total gas flow rate. The arc voltage fluctuation can affect the energy distribution of the plasma jet which is detectable by electrostatic probes and a high-speed video camera. The steadiness of energy transfer is also affected by the laminar or turbulent flow state of the plasma.

A fixed arc length direct current plasma torch for reduced pressure deposition of thin films

Because of its high energy density direct current(dc)thermal plasmas are widely accepted as a processing medium which facilitates high processing rates high fluxes of radical species the potential for smaller jnstallations a wide choice of reactants and high quench rates[1].A broad range of industrial processing methods have been developed based on dc plasma technology. However,nonstationary features limited new applications of dc plasma in advanced processing, where reliability£¬reproducibility and precise controllability are required£. These challenges call for better understanding of the arc and jet behavior over a wide range of generating parameters and a comprehensive control of every aspect of lhe plasma processing.

Ascertainment of cause-specific mortality in COPD - operations of the TORCH clinical endpoint Committee

Background: TORCH (Towards a Revolution in COPD Health) is an international multicentre, randomised, placebo-controlled clinical trial of inhaled fluticasone propionate/salmeterol combination treatment and its monotherapy components for maintenance treatment of moderately to severely impaired patients with chronic obstructive pulmonary disease (COPD). The primary outcome is all-cause mortality. Cause-specific mortality and deaths related to COPD are additional outcome measures, but systematic methods for ascertainment of these outcomes have not previously been described. Methods: A Clinical Endpoint Committee (CEC) was tasked with categorising the cause of death and the relationship of deaths to COPD in a systematic, unbiased and independent manner. The key elements of the operation of the committee were the use of predefined principles of operation and definitions of cause of death and COPD-relatedness; the independent review of cases by all members with development of a consensus opinion; and a substantial infrastructure to collect medical information. Results: 911 deaths were reviewed and consensus was reached in all. Cause-specific mortality was: cardiovascular 27%, respiratory 35%, cancer 21%, other 10% and unknown 8%. 40% of deaths were definitely or probably related to COPD. Adjudications were identical in 83% of blindly re-adjudicated cases ( = 0.80). COPD-relatedness was reproduced 84% of the time ( = 0.73). The CEC adjudication was equivalent to the primary cause of death recorded by the site investigator in 52% of cases. Conclusion: A CEC can provide standardised, reliable and informative adjudication of COPD mortality that provides information which frequently differs from data collected from assessment by site investigators.

Accuracy of Death Certificates in COPD: Analysis from the TORCH Trial

The Towards a Revolution in COPD Health (TORCH) trial was an international clinical trial of chronic obstructive pulmonary disease (COPD) patients where cause of death was assigned by an independent committee. Comparison of death certificate data and adjudicated cause of death allows a unique opportunity to determine death certificate accuracy and frequency of COPD listing on death certificates of COPD patients. In this analysis, the authors determine the concordance between adjudicated cause of death and primary and secondary cause of death from death certificates. In 317 (80%) of informative deaths, the primary or secondary cause of death from certificates agreed with adjudicated cause of death. Only 229 (58%) of death certificates in these COPD patients listed COPD on the certificate. COPD was not listed on the death certificate in 21% of deaths adjudicated to be caused by COPD exacerbation. Compared with pulmonary causes, the listing of COPD on certificates occurred with less frequency than cardiovascular, cancer and other categories of death. The combined primary and secondary listing on death certificates has good concordance with actual cause of death. COPD is under-reported on death certificates, and this under-reporting is more frequent when the primary cause of death is not pulmonary.

The TORCH (towards a revolution in COPD health) survival study protocol

Only long-term home oxygen therapy has been shown in randomised controlled trials to increase survival in chronic obstructive pulmonary disease (COPD). There have been no trials assessing the effect of inhaled corticosteroids and long-acting bronchodilators, alone or in combination, on mortality in patients with COPD, despite their known benefit in reducing symptoms and exacerbations. The "TOwards a Revolution in COPD Health" (TORCH) survival study is aiming to determine the impact of salmeterol/fluticasone propionate (SFC) combination and the individual components on the survival of COPD patients. TORCH is a multicentre, randomised, double-blind, parallel-group, placebo-controlled study. Approximately 6,200 patients with moderate-to-severe COPD were randomly assigned to b.i.d. treatment with either SFC (50/500 microg), fluticasone propionate (500 microg), salmeterol (50 microg) or placebo for 3 yrs. The primary end-point is all-cause mortality; secondary end-points are COPD morbidity relating to rate of exacerbations and health status, using the St George's Respiratory Questionnaire. Other end-points include other mortality and exacerbation end-points, requirement for long-term oxygen therapy, and clinic lung function. Safety end-points include adverse events, with additional information on bone fractures. The first patient was recruited in September 2000 and results should be available in 2006. This paper describes the "TOwards a Revolution in COPD Health" study and explains the rationale behind it.