1,721,066 research outputs found
SIMULAZIONE DINAMICA E CONTROLLO DEI PROCESSI DI GASSIFICAZIONE CON RELATIVO CICLO COMBINATO PER LA COGENERAZIONE DI ENERGIA
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Supervisory control of a selective catalytic reactor for NOx removal in incineration plants
No full textThe purpose of this work is to present an industrial application of an optimization tool for the supervisory control of the NOx reduction section. This work does not pretend to address any new technique of NOx reduction but rather to show the results obtained when a comprehensive on-line optimization tool has been successfully applied. The optimization procedure consists of the search of the best working conditions that satisfy the operating and legal constraints, in terms of emission amounts and combustion quality. This procedure adopts a simulation algorithm and data reconciliation tool to verify and improve the consistency of the calculated values by experimental data. Using such algorithm it is possible to identify all the updated data necessary to optimize the plant's performance. Specifically, the DeNO(x) section optimization, both from an economical and environmental point of view, is strongly related to the estimation of the nitrogen waste mass fraction together with the catalytic reactor efficiency. The results obtained in many case studies show that it is possible to achieve the desired performance and to reduce the operating costs by defining the optimal operating temperature and the corresponding amount of ammonia required for the catalytic reduction of NOx subject to the emission limits. These tools were successfully tested on a municipal waste incineration plant. (C) 1999 Elsevier Science Ltd. All rights reserved
Paracetamol and antibiotics in childhood and subsequent development of wheezing/asthma: Association or causation?
No full textBackground: Several studies found an association between early administration of paracetamol and antibiotics and development of wheezing. This could be due to confounding: wheeze and asthmatic symptoms in early childhood are difficult to distinguish from respiratory tract infections that are widely treated with these drugs; in case of persistence of symptoms up to school age, this could explain the observed relationship. Methods: We investigated the association between paracetamol and antibiotics use in the first year of life and wheezing phenotypes, i.e. wheezing starting in different time periods (early, persistent and late-onset) in the SIDRIA-2 study, a cross-sectional survey of 16 933 children aged 6-7 years. Directed acyclic graph (DAG) was used to depict the causal structure. Results: Paracetamol and antibiotics administration in the first year were associated with early wheezing (first 2 years of life only) [odds ratio (OR): 2.27; 95% confidence interval (95% CI): 1.98-2.62 and OR = 3.76, 95% CI: 3.31-4.27] and with persistent wheezing (first 2 years + last 12 months) (OR = 1.77, 95% CI: 1.49-2.10 and OR = 3.06, 95% CI: 2.60-3.60), whereas the association with late-onset wheezing (in the last 12 months only) was weak (OR = 1.12, 95% CI: 0.97-1.31 and OR = 1.18, 95% CI: 1.02-1.38 for paracetamol and antibiotics, respectively). DAG shows that even in the absence of a direct (causal) arrow from early drugs use to wheezing at school age, the two are associated due to confounding (through the 'infection' node). Conclusions: It is important to take into account different phenotypes in order to disentangle the association of paracetamol and antibiotics with wheezing. Published by Oxford University Press on behalf of the International Epidemiological Association. © The Author 2011; all rights reserved
METODOLOGIE DI CONTROLLO MULTIVARIABILE LINEARE, NON LINEARE E CALCOLO INFERENZIALE PER UNA GESTIONE DINAMICA PIÙ EFFICACE DEI PROCESSI CHIMICI
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HUMAN MYOTONIC DYSTROPHIES: PROTEOME PROFILING AND DIFFERENTIATION STUDIES
Full text linkMyotonic Dystrophy type 2 (DM2) is caused by a DNA microsatellite expansion within the ZNF9 gene leading to an abnormal splicing pattern largely responsible for the pathological condition. To better define the functional changes occurring in human DM2 myotubes, we performed a quantitative proteome comparison between myotubes of DM2 and control patients using two-dimensional gel electrophoresis followed by mass spectrometry. Our results indicate that the proteins, altered in DM2 cultures, belong to two major functional categories: i) mitochondrial components, with a reduction of Elongation factor Tu (EFTu), Heat Shock Protein 60 (HSP60), Glucose Regulated Protein 75 (GRP75) and Dienoyl-CoA-Isomerase, an enzyme involved in fatty acids degradation; ii) the ubiquitin proteasome system, with increase of the 26S proteasome regulatory subunit 13 and a reduction of Proteasome subunit Apha 6 and of Rad23B homolog. Altered ubiquitin-proteasomal activity is supported by a global reduction of cytosolic ubiquitinated proteins, nonetheless the accumulation of ubiquitin-protein conjugates after proteasomal inhibitor MG-132 treatment is maintained in DM2 and control cells, suggesting a higher degradation rate for the proteasome in myoblasts from patients affected by the disease. Although future work is required to clarify how these changes affect the protein degradation machinery and mitochondrial function and to evaluate if these changes also occur in the biopsies of DM2 patients, these results identify the mitochondrial proteins and the ubiquitin-proteasomal system as candidates potentially relevant to DM2 pathogenesis. Further analysis performed in Human skin fibroblasts primary cultures, obtained from patients biopsies, revealed an Hyperpolaryzation of the mitochondrial membrane potential involving DM2 cells, indicating a putative functional issue for mitochondria. As the evaluation of the Cytocrome c release following hydrogen peroxide treatment showed a differential response to this stress inducing compound, we pointed out a functional involvement of the DM2 mitochondrial-mediated cellular response to oxidative stress
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