A general technique for derivation of average current mode controllaws for single-phase power-factor-correction circuits without inputvoltage sensing

This paper presents a general technique to derive average current mode control (CMC) laws without input voltage sensing to achieve high power factor for single-phase topologies operating in continuous conduction mode (CCM). The control laws are derived based on the steady-state input-output voltage relationships and the CCM large-signal averaged pulsewidth modulation (PWM)-switch model. Using this methodology, average CMC laws with linear PWM waveforms are discovered for commonly used single-phase power stage topologies such as boost, flyback, SEPIC, and buck/boost. Conventional three-loop-controlled average CMC converters can now be controlled with a two-loop architecture. Hardware results for a boost power factor correction (PFC) and simulation results for flyback, SEPIC, and buck/boost topologies verify operation. The small-signal models of the current loop and voltage loop are derived for the boost topology and are used for control loop design. Input current harmonic distortion measurements demonstrate improved performance compared to the conventional three-loop control technique     

DC Link Filter Design Considerations in Three-Phase Voltage Source Inverter-Fed Induction Motor Drive System

The dc link filter elements in a three-phase voltage source inverter-fed induction motor system can affect the performance of the drive system if not properly chosen. The requirements, design considerations, and a simplified procedure for the selection of filter component values based on minimization of voltage and current ripple currents in the dc link, damping effects, and on resonant frequency considerations are formulated. Typical computational results and experimental waveforms are presented.     

Integrated decision support system for waste minimization analysis in chemical processes

The need to build and operate environmentally friendly plants has challenged the chemical industry to consider waste minimization or even elimination starting from the early stages of process development. A thorough waste minimization analysis requires specialized expertise and is laborious, time-consuming, expensive, and knowledge-intensive. This has caused a major technical barrier for implementing waste minimization programswithin the industry. Previously, we had reported a systematic methodology and a knowledge-based system, called ENVOPExpert, for identifying waste minimization opportunities in chemical processes. In this paper, we propose an integrated qualitative-quantitative methodology to identify waste minimization alternatives and assess their efficacy in terms of environmental impact and process economics. A qualitative analysis is first conducted to identify the sources of wastes and to propose alternatives for eliminating or minimizing them. Environmental impact of each alternative is then calculated by doing a quantitative pollutant balance. The capital expenditure required for implementing the alternative and the resulting plant operating costs are also calculated and used in the evaluation of the waste minimization alternatives. Through this, practical and cost-effective options can be identified. This methodology has been implemented as an integrated decision support system and tested using the hydrodealkylation process case study with satisfactory results.     

The physiological diagnosis of neurocirculatory dystonia

The authors of the present article were the first to work out theoretical foundations and methods of physiological diagnosis of neurocirculatory dystonia. Criteria of tension of myocardial functional structures and central regulatory mechanisms have been identified both in healthy subjects and cardiological patients. It has been ascertained that degree and systematic character of tension cause the physiological risk factors for cardio-pathology to develop, 6 types were identified of loading adaptation of the heart caused by extent of its tension, in individuals with neurocirculatory dystonia. Each of the types disclosed is characterized by a dynamics of the functional volumes proportions as well as by peculiarities of the adaptation mechanisms. Physiological diagnosis of functioning of the heart is one of major methods of the primary prophylaxis of neurocirculatory dystonias as well as prevention of aggravation of their course.     

Design of constructions for the expression of proteolytic antibody light chain

A new system for the expression of a catalytic light chain antibody to the vasoactive intestinal peptide is described. The system made possible the isolation the large amounts of a homogeneous protein without any additional peptide domains. The preparation obtained can be used in further experiments on light chain crystallization and in X-ray-structural analysis of its catalytic center.     

Necrotizing fasciitis

Necrotizing fasciitis is a rare soft tissue infection with a high rate of mortality. Decreased capacity of the immune response is the overall disposing factor. Necrotizing fasciitis can develop very rapidly, and a rapid diagnosis and aggressive surgery provides the best prognosis.     

Synthesis and biological activity of novel thiazolidinediones

Novel compounds having a dual pharmacophore were synthesised and evaluated for their insulin sensitiser and anti-inflammatory properties in different animal models.