Shafts of technological machines with combined supports

This article discusses experimental studies of a saw cylinder (SC) composite shaft with combined support. We proposed a new design of the support that provides a reduction in the shaft. The article considers the influence of changing the parameters of the elastic element of the support of the composite shaft (CS) of the SC using the ANSYS software, calculates and analyzes the reaction forces of the supports for different parameters of the elastic elements, and also considers the effect on the stresses of the system, as well as the results of experimental and comparative tests in production conditions on the SC of the cotton gin machines with a composite bearing, where the parameters of the elastic element differ from each other by different elasticity. The fiberization process took place according to the established technological parameters. The experimental and standard SC models were compared during the experiment

Current trends in cannulation and neuroprotection during surgery of the aortic arch in Europe†‡

OBJECTIVES To conduct a survey across European cardiac centres to evaluate the methods used for cerebral protection during aortic surgery involving the aortic arch. METHODS All European centres were contacted and surgeons were requested to fill out a short, comprehensive questionnaire on an internet-based platform. One-third of more than 400 contacted centres completed the survey correctly. RESULTS The most preferred site for arterial cannulation is the subclavian-axillary, both in acute and chronic presentation. The femoral artery is still frequently used in the acute condition, while the ascending aorta is a frequent second choice in the case of chronic presentation. Bilateral antegrade brain perfusion is chosen by the majority of centres (2/3 of cases), while retrograde perfusion or circulatory arrest is very seldom used and almost exclusively in acute clinical presentation. The same pumping system of the cardio pulmonary bypass is most of the time used for selective cerebral perfusion, and the perfusate temperature is usually maintained between 22 and 26°C. One-third of the centres use lower temperatures. Perfusate flow and pressure are fairly consistent among centres in the range of 10-15 ml/kg and 60 mmHg, respectively. In 60% of cases, barbiturates are added for cerebral protection, while visceral perfusion still receives little attention. Regarding cerebral monitoring, there is a general tendency to use near-infrared spectroscopy associated with bilateral radial pressure measurement. CONCLUSIONS These data represent a snapshot of the strategies used for cerebral protection during major aortic surgery in current practice, and may serve as a reference for standardization and refinement of different approache

The Effect of Sewer Weight on the Productivity of Early Farm Potatoes

 In this article, the effect of seed weight on the growth and development of potatoes is described. It is stated that the increase in weight of seed pods is directly related to the intensity of seedling formation, the number of stems formed in each bush, more or less formation of leaf sheaths, and the degree of infection of potato plants with diseases depends on seed weight

«Miniature» Approach for Pyeloplasty in Children: Primary Use Experience Report

Currently, laparoscopic pyeloplasty is gaining popularity in pediatric urology due to less invasive compared to the open standard pyeloplasty. Nevertheless, there are basic “critical” remarks about this pyeloplasty technique in children, which involve some difficulties in comparing tissues and intracorporeal suturing due to the limited available space. In addition, a significant negative point of laparoscopic pyeloplasty is the duration of the operation, especially in the younger age group of children. Despite all the advantages associated with minimal invasiveness, there are alternative methods of surgical treatment, which show quite impressive results. In our practical work, we performed minimally invasive open pyeloplasty: with a miniature incision, in a child with ureteropelvic junction obstruction with a good result. In addition, this access provides a wide exposure of the ureteropelvic junction and easy tissue manipulation

Features of ultrafiltration process engineering calculation in concentration and purification of pectin polysaccharides

In this paper, we propose a mathematical model of the process of changing the productivity of a membrane, both through the formation of a continuous gel layer, and by blocking individual pores. Also, the results of modeling the process of dia- ultrafiltration (DUF) purification of pectin solutions and their concentration by ultrafiltration (UF) using hollow fiber membranes are presented. The effect of periodic washing of the membrane and the process of gelation along the membrane on the productivity of the plant was studied. Thus, the process is characterized by two parameters, and A is the main parameter of the problem, which is the same for all stages, and the second parameter, the ratio (k =F0/F'), characterizes the degree of pore purification with a general cleaning of the membrane surface and is thus one from the characteristics of a single cycle. The valuesof a number of parameters are determined experimentally. It is shown that when the system of differential equations, represented in the normal Cauchy form describing the given technological process, is jointly solved, the productivity of the DUF system can be increased by the frequency of flushing. The conducted experiments demonstrated the advantage of the use of the DUF process in the production of pectin and the features of purification and concentration of apple and sunflower pectins in this process. It is established that the use of DUF causes the introduction of an energy-saving technological process in the production of pectin to produce the target product that meets the required quality and environmental safety of production. The introduction of the proposed methods of DUF and UF into the production of pectin leads to an improvement in the quality and cost of the product