Remodelling of the atrioventricular canal myocardium determines atrioventricular conduction patterns

Developmen

Remodelling of the atrioventricular canal myocardium determines atrioventricular conduction patterns

Developmen

Relationship study between the student learning approach in the occupational safety and health field and acquired competencies

Purpose: To search for training methods for specialists in industrial safety, environmental and occupational safety and health in conditions of insufficient (or absent) laboratory support and to study the relationship between the student learning approach and acquired competencies. Design/methodology/approach: To study modern advances in industrial safety, environmental and occupational safety and health and training methods for specialists a systematic literature review approach has been used. For publications from 2017, queries were asked through keywords and safety related topics. To relationship study between the student learning approach and acquired competencies a student survey on random sampling has been used. A total of 112 students of the 3rd and 4th year of study at the university were interviewed. Findings: The results of the survey showed that the students’ number who simultaneously successfully answered theoretical questions and completed practical tasks is 33.8% from the group with theoretical training and 75% from the group that was trained in the workplace. The relationship between the groups with a visit to the existing enterprise and acquired competencies was justified by the association coefficient and contingency coefficient that are 0.7 and 0.4 respectively. Research limitations/implications: A student’s survey was conducted at only one university. Questions were asked only according to the curriculum of the course “Labour Protection”. No survey for other training courses conducted. Practical implications: The research results are reasonable and can be applied at universities to improve the educational process of training specialists. Originality/value: It was proposed that students be trained using existing enterprises as a laboratory base and by the methods of statistics mathematical processing was substantiated the proposal feasibility

Apoptosis and epicardial contributions act as complementary factors in remodeling of the atrioventricular canal myocardium and atrioventricular conduction patterns in the embryonic chick heart

Developmen

Development of the System to Control Milk Acidity in the Milk Pipeline of a Milking Robot

Acidity characterizes the suitability of milk for primary processing and is one of the key parameters monitored when accepting it at a dairy plant. Therefore, it is important to timely separate milk with lowered acidity in the process of milking by a robot. However, no technical means for the detection and separation of milk with lowered acidity in a milk pipeline were designed for robotic milking systems.Based on the results of experimental study, we established a linear correlation dependence of milk acidity, using a traditional Turner method, on pH. We calculated parameters for the main and additional containers, for milk of superior grade and for non-standard milk in terms of acidity. Linear parameters are determined for inserting into the main milk pipeline of a robot the measuring pH-electrode and a tee with electromagnetic valve for the automated discharge of non-standard milk. Based on the experimental study and our calculations, we developed a project of the technical system for the robotic cow milking technology. A standard technology is complemented by a process of automated measurement of milk pH in a flow, which is implemented using a high-speed transistor pH-FT electrode with a measuring unit.Control over milk pH in a flow during milking makes it possible to operatively solve two tasks at a time ‒ to improve the accuracy of estimating the quality of starting raw materials and to correct the feed of cows in order to standardize the acidity of milk required for its acceptance at a milk processing plant. We thus exclude a labor-intensive laboratory operation for determining the acidity because this indicator has already been measured during robotic milking process. Therefore, our improvement of technology for robotic milking will make it possible to more accurately assess the quality of raw milk using milking robots that are included in the system of machines for precision cattle breeding

Identifying Changes in the Technical Parameters of Milking Rubber Under Industrial Conditions to Elucidate Their Effect on the Milking Process

Many years of experience in the operation of milking machines show that milking rubber was and remains a short-lived and unreliable link in the technological process of machine milking. During operation, rubber quickly loses its strength and elastic properties, becomes stiff and less elastic, deforms, and changes its shape. The purpose of this study is to identify changes in the technical parameters of milking rubber under industrial conditions in order to establish their impact on the milking process. The obtained results could make it possible to rationally choose the milking rubber for teat cups, which would ensure an effective milking process. During this study's initial stage, the physical and mechanical condition of milking rubber was experimentally established at steam disinfection and as a result of saturating the article with milk fats. The following stage implied detecting the effect of milking rubber tension in a teat cup on the speed of milking. It was established that milking rubber during operation is actively exposed to milk fat, which leads to the loss of its weight relative to its original value. On day 1,000 of work, the weight loss relative to the initial value (100 g), under the washing regime temperature of 85 °C, 50 °C, 35 °C, and 20 °C, was 1 g, 3.3 g, 5 g, and 4.2 g, respectively. The dependences have been derived for the swell mass of milking rubber M on the temperature of washing solutions T and the duration of operation t as a result of saturation with milk fats. The dependence of milk yield rate V on the tension force of milking rubber F in teat cups has been established. Thus, it was found that when the tension force of milking rubber changes from 25 to 60 N, the difference in the average intensity of milk yield is 0.13 kg/min (10.8 %). Regarding the amount of milk yield at the specified tension, the difference is 0.15 kg (2.5 %). At rubber tension from 60 to 25 N, the average milking time increases by 0.46 min (8.3 %). Thus, it was determined that a milking machine with milking rubber at different tension over a total milking time would unevenly milk different parts of the cow's udder. The study reported here expands the idea about the technical and manufacturing characteristics of rubber articles, namely changes in them at steam disinfection and as a result of saturation with milk fat