OPTIMIZATION OF MULTISTREAM CASCADES WITH A GIVEN NUMBER OF GAS CENTRIFUGES FOR PURIFICATION OF REGENERATED URANIUM HEXAFLUORIDE FROM 232, 234, 236U

method for optimization of multistream cascades for purification of regenerated ura-nium from even isotopes is improved by using several types of stages with a given number of gas centrifuges. The operating modes of the stages have been determined by the artificial bee colony algorithm

Optimization of the Cascade with Two Additional Product Flows for the Simultaneous Concentration of Intermediate Molybdenum Isotopes

A technique has been developed for optimizing multiflow cascades to obtain highly concentrated intermediate molybdenum isotopes. A computational experiment was carried out to separate a mixture of molybdenum isotopes. Various cases for the separation of molybdenum isotopes in cascades with large step separation coefficients corresponding to gas centrifuges were considered. It is shown that using of the bee swarm optimization has an advantage over the Hook-Jeeves method. © 2020 American Institute of Physics Inc.. All rights reserved

Anodic Dissolution of Non-Ferrous Metals in a Glycerate-Alkali Electrolyte

Studies have been conducted to assess the possibility of refining a lead collector containing precious metals, with the aim of obtaining lead using an economically viable technology. Studied the patterns of anodic oxidation of lead and impurities in alkaline-water-glycerate electrolytes, depending on the concentration of sodium hydroxide and glycerol in the electrolyte, the potential sweep rate. © 2020 Trans Tech Publications Ltd, Switzerland

USING DEXMEDETOMIDINE AS THE MAIN AGENT FOR ANESTHETIC MANAGEMENT DURING RADIOSURGERY IN A CHILD

This clinical case demonstrates specific features of anesthetic management during radiosurgery in pediatric patients considering the limited access to them during continuous manipulations with pharmacological sedation. Considering the age of the child, dexmedetomidine, the drug from the group of agonists of α2-adrenergic receptors, was used as the main agent. It was used since it could be administred by the noninvasive way for premedication and intravenously in a form of infusion to provide the necessary depth of sedation with preservation of spontaneous breathing and minimization of uncontrolled motions of the patient

Production of highly concentrated intermediate molybdenum isotopes in optimal cascade with two additional product flows

The problem of highly concentrated molybdenum isotopes production in multiflow cascades is considered. A method of the cascade with two additional product flows optimization has been developed. Two components intermediate in weight are concentrated simultaneously in those flows. The optimization problem is solved using a variation of the partial flow cuts of the cascade stages with large separation coefficients. The optimization criterion is the minimum of the stage total feed flow while ensuring a given concentration of isotopes. A computational experiment was carried out to separate a mixture of molybdenum hexafluoride. The experiment demonstrated the features of intermediate components concentrating in additional product flows of the cascade. © 2020 Published under licence by IOP Publishing Ltd

Ordinary Cascades for Purification of Reprocessed Uranium Hexafluoride from 232,234,236U Isotopes

Reprocessed uranium gained from the spent nuclear fuel contains 232,234,236U isotopes within, which considerably hamper its reuse. It is proposed to use an ordinary cascade to reduce the concentration of 232,234U. The output purified from 232,234U is obtained in the cascade waste. The authors analysed the peculiarities of reducing concentration of 236U after the enrichment of reprocessed uranium hexafluoride in terms of 235U in the ordinary cascade and its subsequent dilution. A computational experiment was performed. Parameters of cascade stages were predetermined, which allow to reduce the content of 232,234,236U to an acceptable level. © 2022 Institute of Physics Publishing. All rights reserved

Separation of boron isotopes in optimal cascade of uniflow gas centrifuges

Was considered a problem of an optimization of concurrent gas centrifuges for separation of Boron isotopes in form of trifluoride BF3. As the criteria was used a minimum of total number of gas centrifuges upon the given external parameters of the cascades' scheme. The method is based on the analytical relationships for the flows of stages, received under approximating minimization of the total feed flow. Conducted cascade calculations showed that it is possible to obtain BF3 with enrichment up to 99.9 % of 10B in the selection and up to 0.1 % in the waste, which is equivalent to 99.9 % of 11B. © 2020 Published under licence by IOP Publishing Ltd

Epidemiology, practice of ventilation and outcome for patients at increased risk of postoperative pulmonary complications

BACKGROUND Limited information exists about the epidemiology and outcome of surgical patients at increased risk of postoperative pulmonary complications (PPCs), and how intraoperative ventilation was managed in these patients. OBJECTIVES To determine the incidence of surgical patients at increased risk of PPCs, and to compare the intraoperative ventilation management and postoperative outcomes with patients at low risk of PPCs. DESIGN This was a prospective international 1-week observational study using the ‘Assess Respiratory Risk in Surgical Patients in Catalonia risk score’ (ARISCAT score) for PPC for risk stratification. PATIENTS AND SETTING Adult patients requiring intraoperative ventilation during general anaesthesia for surgery in 146 hospitals across 29 countries. MAIN OUTCOME MEASURES The primary outcome was the incidence of patients at increased risk of PPCs based on the ARISCAT score. Secondary outcomes included intraoperative ventilatory management and clinical outcomes. RESULTS A total of 9864 patients fulfilled the inclusion criteria. The incidence of patients at increased risk was 28.4%. The most frequently chosen tidal volume (VT) size was 500 ml, or 7 to 9 ml kg1 predicted body weight, slightly lower in patients at increased risk of PPCs. Levels of positive end-expiratory pressure (PEEP) were slightly higher in patients at increased risk of PPCs, with 14.3% receiving more than 5 cmH2O PEEP compared with 7.6% in patients at low risk of PPCs (P < 0.001). Patients with a predicted preoperative increased risk of PPCs developed PPCs more frequently: 19 versus 7%, relative risk (RR) 3.16 (95% confidence interval 2.76 to 3.61), P < 0.001) and had longer hospital stays. The only ventilatory factor associated with the occurrence of PPCs was the peak pressure. CONCLUSION The incidence of patients with a predicted increased risk of PPCs is high. A large proportion of patients receive high VT and low PEEP levels. PPCs occur frequently in patients at increased risk, with worse clinical outcome

ПРИМЕНЕНИЕ ДЕКСМЕДЕТОМИДИНА В КАЧЕСТВЕ БАЗОВОГО СРЕДСТВА ДЛЯ АНЕСТЕЗИОЛОГИЧЕСКОГО ОБЕСПЕЧЕНИЯ РАДИОХИРУРГИЧЕСКОГО ЛЕЧЕНИЯ У РЕБЕНКА

This clinical case demonstrates specific features of anesthetic management during radiosurgery in pediatric patients considering the limited access to them during continuous manipulations with pharmacological sedation. Considering the age of the child, dexmedetomidine, the drug from the group of agonists of α2-adrenergic receptors, was used as the main agent. It was used since it could be administred by the noninvasive way for premedication and intravenously in a form of infusion to provide the necessary depth of sedation with preservation of spontaneous breathing and minimization of uncontrolled motions of the patient.Настоящее клиническое наблюдение демонстрирует особенности анестезиологического обеспечения радиохирургического лечения педиатрических пациентов в условиях ограниченного доступа к ним во время длительных процедур с использованием фармакологической седации. Ввиду возрастных особенностей ребенка в качестве базового средства использован дексмедетомидин ‒ препарат из группы центральных α2-адреноагонистов. Его применили благодаря возможности использовать неинвазивно для премедикации и внутривенно в виде инфузии для поддержания необходимой глубины седации с сохраненным самостоятельным дыханием, а также для минимизации самопроизвольных движений пациента