Soft-switching Inverter-fed Single-phase Collector Motor Drive

AbstractThis paper deals with the performance analysis of a hand power tool (HPT). The HPT is being driven by a single-phase collector motor drive fed by a PWM voltage source soft-switching inverter. A mathematical model of an electro-mechanic system of a HPT has been worked out. The dynamic model of an electric motor consists of a system of non-linear differential equations that include the resistance and dynamic inductance of an armature and field winding and spinning E.M.F. The proposed drive system is modeled and its performance is simulated in Matlab/Simulink. The simulation results show that a smaller switching loss and higher conversion efficiency are obtained by the proposed soft-switching inverter. The performance of the drive is improved by using voltage regulator when compared with direct connection to the voltage source

Ингвино-скротална хернија на мочен меур

Herniation of urinary bladder through the inguinal canal is a rare disease that requires surgery. The resulting combination of failure of the abdominal wall and an increase in intra-abdominal pressure occurs prolapse of the urinary bladder in the inguinal canal and the occurrence of ingvino-scrotal hernia. This phenomenon is very rare and often misdiagnosed. It occurs more often in older men with increased body weight and symptoms of distal urinary obstruction and urinary infections. The symptoms usually are mild to moderate, associated with hindered urination and urinary infections, and if this condition promptly left untreated can lead to serious health problems, to renal failure. CT reconstruction in three planes is the method of choice in the diagnosis of ingvino-scrotal hernia of the bladder. This method provides a clear display of herniated part of the urinary bladder, and allows detection of the contents of the hernial sac.Хернијацијата на мочниот меур преку ингвиналниот канал е ретка болест која бара хируршка интервенција. Како резултат на комбинација на слабост на абдоминалниот ѕиди зголемување на интраабдоминалниот притисок се јавува пролапс на мочниот меур во ингвиналниот канал и појава на ингвино-скротална хернија. Оваа појава е многу ретка и често погрешно се дијагностицира. Се јавува почесто кај постари мажи со зголемена телесна тежина и со симптоми на опструкција на дисталните уринарни патишата и уринарни инфекции. Симптомите вообичаено се од благи до умерени, поврзани се со отежнатото мокрење и уринарни инфекции, а доколку оваа состојба навремено не се лекува може да доведе до посериозни здравствени проблеми, па се до бубрежна инсуфициенција. CT со реконструкција во три рамнини е метода на избор во дијагностиката на ингвино-скроталните хернии на мочниот меур. Оваа метода овозможува јасен приказ на хернираниот дел од мочниот меур, а овозможува и детекција на содржината на килната кеса

Systems Evolutionary Biology of Waddington’s Canalization and Genetic Assimilation

In recent years, there has been growing interest in computer modeling of the evolution of gene and cell regulatory networks, in general, and in computational studies of the classic ideas of Baldwin, Schmalhausen, Waddington, and followers, in particular. Two related aspects of Waddington’s evolutionary theories are the concepts of canalization and of genetic assimilation. Canalization is associated with the robust development of an individual to diverse perturbations and noise, though, when fluctuations in developmental factors exceed a particular limit, the normal developmental trajectory can be “thrown out” of the robust canal, resulting in an altered phenotype. If selective pressure favors the new phenotype, an initial individual loss of canalization can lead to phenotypic changes in the population (with canalization then becoming established for the new phenotype). Genetic assimilation is the subsequent genetic fixing of the new trait in the population. Recent experimental and theoretical works have established a quantitative basis for these classic concepts of Waddington; this chapter will review these new developments in systems evolutionary biology

Full-arch fixed overdenture in lower jaw - immediate solution for efficient mastication

Complete anodontia and alveolar ridge resorption are responsible for lack of retention and stabilization of conventional acrylic lower denture. Hybrid prostheses on 4 implants placed immediately in the first 7 days is therapeutic solution which allows patients better chewing and increased effective masticatory force. Aim: The study aims to assess the functional and subjective treatment outcomes of full-arch fixed overdenture hybrid rehabilitation. Material and Methods: 60 patients with hybrid prostheses over 4 implants were included in the study. The measurement of the masticatory force was done in the chewing center in the projection of the distally placed implant. Electro-gnathic-dynamometer measured the force of the muscle elevator and depressor of the mandible. Sensor was placed in plastic bite templates and the force value was registered three times. Results: The mean masticatory forces measured in the chewing center before implants and overdenture were 95.7 N. One month later with the prosthesis the value was increased to 185.6 N and after 18 months 186.2 N. Conclusion: There is significant increase in masticatory force in area of ​​the distal implant. This is indicating increased resistance to load and higher efficiency of the chewing process after the treatment. Keywords: overdenture, full-arch, hybrid prosthesi