Comparative analysis of polychlorinated biphenyl decomposition processes in air or argon (plus oxygen) thermal plasma

Thermal plasmas may solve one of the biggest toxic waste disposal problems. The disposal of polychlorinated biphenyls (PCBs) is a long standing problem which will get worse in the coming years, when 180 000 tons of PCB-containing wastes are expected to accumulate in Europe (Hot ions break down toxic chemicals, New Scientist, 16 April 1987, p. 24.). The combustion of PCBs in ordinary incinerators (at temperature T similar to 1100 K, as measured near the inner wall of the combustion chamber (European Parliament and Council Directive on Incineration of Waste (COM/99/330), Europe energy, 543, Sept. 17, 1999, 1-23,)) can cause more problems than it solves, because highly toxic dioxins and dibenzofurans are formed if the combustion temperature is too low (T LT 1400 K). The paper presents a thermodynamic consideration and comparative analysis of PCB decomposition processes in air or argon (+oxygen) thermal plasmas. (C) 2000 Elsevier Science B.V. All rights reserved

Thermal plasma synthesis of ultrafine Si3N4 and SiC ceramic powders

Thermal plasma processes for ultrafine ceramic powders synthesis are discussed and explained by examples of Si3N4 and SiC powder synthesis routes, consisting of silicon powder evaporation in nitrogen plasma, followed by reactive quenching with ammonia or propane-butane gas. Basic results of a) theoretical calculations, analysis and predictions, and b) experimental investigations on a 100 kW DC plasma installation with some of the characteristics of the obtained ultrafine Si3N4 and SiC powders are presented in the paper.Advanced Materials for High Technology Applications, 1st Yugoslavian Advanced Materials Conference - Advanced Materials 95 on Challenges of Tomorrow, Sep 18-22, 1995, Herceg Novi, Yugoslavi

Thermodynamic consideration of Si-N and Si-H-N systems for silicon nitride powder production in thermal plasma

The results of equilibrium composition and total enthalpy computation in the temperature range of 1000-6000 K and at 1 bar for Si-N and Si-H-N systems are presented in the paper. These data enable temperature and energy parameters determination and optimization of the process for ultrafine silicon nitride powder production, in which silicon powder evaporation in a nitrogen thermal plasma is followed by quenching with nitrogen or ammonia

Thermodynamic consideration of the plasma process for boron nitride powder production from boric acid

The results of equilibrium composition and total enthalpy computation in the temperature range of 1000 to 6000 K and at pressure of 1 bar, for the systems B-O-H-N and B-O-C-H-N are presented in this paper. These data enable the determination, and optimization of mass, temperature and energy parameters of the process for the production of ultrafine boron nitride powder by the decomposition of boric acid in a nitrogen plasma, followed by reactive quenching with cold methane

Optimal plasma process routes for boron nitride (BN) powder production from boric acid (H3BO3)

The results of equilibrium composition and total enthalpy computation in the temperature range of 1000 to 6000 K and at pressure of 1 bar, for the systems LT (BOHN)under bar GT and LT (BOCHN)under bar GT are presented in the paper. These data enable the determination, and optimization of mass, temperature and energy parameters of the process for ultrafine boron nitride powder production by the boric acid (H3BO3) decomposition in nitrogen plasma, followed by reactive quenching with cold methane or propane-butane gas. In both cases for the optimized processes yield of boron nitride powder can be up to 100% in wide temperature range. (C) 2000 Elsevier Science Ltd and Techna S.r.l. All rights reserved

Thermodynamic consideration of the plasma process for boron nitride powder production from boric acid

The results of equilibrium composition and total enthalpy computation in the temperature range of 1000 to 6000 K and at pressure of 1 bar, for the systems B-O-H-N and B-O-C-H-N are presented in this paper. These data enable the determination, and optimization of mass, temperature and energy parameters of the process for the production of ultrafine boron nitride powder by the decomposition of boric acid in a nitrogen plasma, followed by reactive quenching with cold methane

Optimal thermal plasma processes for zirconium carbide powder production from zircon concentrates

Available results of equilibrium composition and total enthalpy computation for the systems: Zr-Si-O-Ar and Zr-Si-O-C-H-Ar? presented in the paper, enables thermodynamic optimization of the plasma process for zirconium carbide production from zircon. In the first step of the considered process, zircon decomposition to zirconia and silica is followed by their evaporation in argon thermal plasma. In the second step by introduction of methane or propane-butane gas in the Zr-Si-O-Ar system and reactive quenching, the temperature of such obtained Zr-Si-O-C-H-Ar is lowered to a range in which it is possible to deposit zirconium carbide powder. On presented examples the procedure of determination of optimal mass, energy and temperature process parameters is demonstrated. From presented data, it is possible to calculate and optimize process parameters for any other thermodynamic conditions. (C) 2001 Elsevier Science Ltd and Techna S.r.l. All rights reserved

Interrogating host immunity to predict treatment response in inflammatory bowel disease

IBD treatment is undergoing a transformation with an expanding repertoire of drugs targeting different aspects of the immune response. Three novel classes of drugs have emerged in the past decade that target leukocyte trafficking to the gut (vedolizumab), neutralize key cytokines with antibodies (ustekinumab) and inhibit cytokine signalling pathways (tofacitinib). In advanced development are other drugs for IBD, including therapies targeting other cytokines such as IL-23 and IL-6. However, all agents tested so far are hampered by primary and secondary loss of response, so it is desirable to develop personalized strategies to identify which patients should be treated with which drugs. Stratification of patients with IBD by clinical parameters alone lacks sensitivity, and alternative modalities are now needed to deliver precision medicine in IBD. High-resolution profiling of immune response networks in individual patients is a promising approach and different technical platforms, including in vivo real-time molecular endoscopy, tissue transcriptomics and germline genetics, are promising tools to help predict responses to specific therapies. However, important challenges remain regarding the clinical utility of these technologies, including their scalability and accessibility. This Review focuses on unravelling some of the complexity of mucosal immune responses in IBD pathogenesis and how current and emerging analytical platforms might be harnessed to effectively stratify and individualise IBD therapy