Анализ локализации корней интервального полинома в заданном секторе

Анализируется отображение параметрического многогранника полинома в сектор Г[m] корневой плоскости, определяемый числом m интервальных коэффициентов. Находятся (2m-2) вершин многогранника, отображение которых в сектор Г[m] гарантирует локализацию в нем всех корней интервального полинома. Формулируются критерии локализации корней в заданном секторе Г при различных соотношениях его угла с углом сектора Г[m]

Heat integration of an Olefins Plant: Pinch Analysis and mathematical optimization working together

This work explores a two-step, complexity reducing methodology, to analyze heat integration opportunities of an existing Olefins Plant, identify and quantify reduction of energy consumption, and propose changes of the existing heat exchanger network to achieve these goals. Besides the analysis of plant design conditions, multiple operational scenarios were considered to propose modifications for handling real plant operation (flexibility). On the strength of plant complexity and large dimension, work methodology was split into two parts: initially, the whole plant was evaluated with traditional Pinch Analysis tools. Several opportunities were identified and modifications proposed. Modifications were segregated to represent small and independent portions of the original process. One of them was selected to be re-analyzed, considering two scenarios. Reduction of problem dimension allowed mathematical methodologies (formulation with decomposition, applying LP, MILP and NLP optimization methods) to synthesize flexible networks to be applied, generating a feasible modification capable of fulfilling the proposed operational scenarios

Correction: Pulsed moxifloxacin for the prevention of exacerbations of chronic obstructive pulmonary disease: a randomized controlled trial

BACKGROUND: Acute exacerbations contribute to the morbidity and mortality associated with chronic obstructive pulmonary disease (COPD). This proof-of-concept study evaluates whether intermittent pulsed moxifloxacin treatment could reduce the frequency of these exacerbations. METHODS: Stable patients with COPD were randomized in a double-blind, placebo-controlled trial to receive moxifloxacin 400 mg PO once daily (N = 573) or placebo (N = 584) once a day for 5 days. Treatment was repeated every 8 weeks for a total of six courses. Patients were repeatedly assessed clinically and microbiologically during the 48-week treatment period, and for a further 24 weeks' follow-up. RESULTS: At 48 weeks the odds ratio (OR) for suffering an exacerbation favoured moxifloxacin: per-protocol (PP) population (N = 738, OR 0.75, 95% confidence interval (CI) 0.565-0.994, p = 0.046), intent-to-treat (ITT) population (N = 1149, OR 0.81, 95% CI 0.645-1.008, p = 0.059), and a post-hoc analysis of per-protocol (PP) patients with purulent/mucopurulent sputum production at baseline (N = 323, OR 0.55, 95% CI 0.36-0.84, p = 0.006).There were no significant differences between moxifloxacin and placebo in any pre-specified efficacy subgroup analyses or in hospitalization rates, mortality rates, lung function or changes in St George's Respiratory Questionnaire (SGRQ) total scores. There was, however, a significant difference in favour of moxifloxacin in the SGRQ symptom domain (ITT: -8.2 vs -3.8, p = 0.009; PP: -8.8 vs -4.4, p = 0.006). Moxifloxacin treatment was not associated with consistent changes in moxifloxacin susceptibility. There were more treatment-emergent, drug related adverse events with moxifloxacin vs placebo (p < 0.001) largely due to gastrointestinal events (4.7% vs 0.7%). CONCLUSIONS: Intermittent pulsed therapy with moxifloxacin reduced the odds of exacerbation by 20% in the ITT population, by 25% among the PP population and by 45% in PP patients with purulent/mucopurulent sputum at baseline. There were no unexpected adverse events and there was no evidence of resistance development. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00473460 (ClincalTrials.gov)

Process Integration: Designing for Energy, Capital and Operability

Over the last five years, significant energy savings have been achieved by several international companies using the pinch concept for heat integration. New concepts are now being added to help the designer deal with capital cost minimization and the task of finding flexible integrated structures. As a result it is possible to save energy, reduce capital cost and enhance flexibility

Integrated Design of Chemical Processes and Utility Systems

The pinch concept for integrated heat recovery networks has recently become established in chemical process design. This paper presents an overview of the concept and shows how it has now been extended to total process design (reactors, separators, etc.) and to the task of interfacing processes with their utility systems (furnaces, steam levels, turbines, etc.

Pinch Technology for the Synthesis of Optimal Heat and Power Systems

Over recent years a new methodology for the analysis and design of heat exchanger networks, called pinch technology, has led to significant energy savings in the chemical and process industries. The methodology has later been extended to apply to integrated heat and power systems (Townsend and Linnhoff, 1983). This paper shows that pinch technology is firmly based in Second Law Analysis. In contrast to conventional Second Law Analysis, however, it does not require a base case design. Rather, it performs true synthesis. Also, it is capable of a methodical distinction between “inevitable” and “avoidable” exergy losses.</jats:p