Computer Modeling and Calculation of the Ventilation Systems for Workplaces and Premises of Electric Welding Production

The most important means of protecting the labor of electric welders is local exhaust ventilation, if required supplemented by general exchange ventilation of electric welding rooms, which contributes to maintaining the normalized state of the air environment. In real conditions, the dust-gas environment of the welding station is influenced by a combination of factors such as the location of welders breathing zone, the relative location of the welding point, and the suction opening of the exhaust device, and the air mobility associated with the aerodynamic interaction of the supply and exhaust devices. The desire to reduce the productivity and energy consumption of exhaust devices usually leads to a change in their effect on the state of the air environment. Therefore, along with the design features of the air extract, it is of great importance that the designs of the exhaust devices correspond to the nature of the welding work performed, as well as the space-planning solution for the mutual arrangement of welding posts and supply and exhaust devices, especially in the rooms with a limited volume. The article is devoted to the analysis of the effect of these factors on the dust and gas environment of the electric welding stations, and the search for their rational combination by the method of computer modeling using the Ansys Fluent hydrodynamic package. To approximate the complex dependence of the carryover into the room, and the concentration in the breathing zone of harmful impurities on the main influencing factors, it is proposed to use a neural network of direct propagation. The architecture and results of testing a neural network model of one of the types of exhaust devices are presented.

Optimization of the Cutting Tool for Internal Flash Removing Operations in the Production of Electric-Welded Tubes

The article considers the structural optimization results for the process of mechanic removing inside flash during the production of longitudinal electric-welded pipes with a diameter of 60.3 ... 89.0 mm. Mechanical processing was performed with a pipe electric welding unit, designed for the manufacture of pipes with a diameter of 60.0 ... 178.0 mm, using various cutting tools and grades of hard alloys. The influence of the parameters of chip formation and cutting forces on the quality of inside flash removing in a longitudinal electric-welded pipe is found. The experiments were carried out using both the basic and experimental geometry of the cutting tool. The dependence of the tool durability at the operation of flash removing on the hardness of the alloy and the wear resistance of the coating has been studied. The analysis of the results of the study of annular inserts made of a three-carbide hard alloy with a multilayer wear-resistant coating showed the possibility of reducing the consumption of cutting tools and emergency stops of the mill, improving the quality of processing and the rate of yield.

Histotopographic and morphometric characteristics of the oral mucosa postoperative wounds healing, depending on the method of connecting the wound edges

Implementation of high-quality tissue connections and hemostasis in oral surgery is an urgent problem of modern dentistry, due to the lack of available universal methods that would help to facilitate the work of oral surgeon and reduce wound healing time. The aim of the research. To investigate and study the regeneration processes in the oral mucosa after high-frequency electric welding, suturing and medical adhesive composition. Materials and methods. This study compared the effect of three connection methods and hemostasis: high-frequency electric welding (EKVZ-300M1 “PATONMED®”, Ukraine), suture method (nylon 5/0 “PIRUS®”, China), adhesive composition (“Histoacryl®”, Germany). 72 rabbits were involved in experiment. An incision of the soft tissues of the vestibulum of the oral cavity of the maxilla with a length of 1.3–1.5 cm was made. On days 3, 7, 14 and 21, tissue samples were excised, histological and morphometric examination of the material were performed. Results. By statistical data processing of 72 rabbits was found that the reliability of differences in the levels of morphometric parameters between groups on each day is very high, as evidenced by the calculated values ​​of the U-test. In 38 cases (90.5 %), the significance level was p≤0.01, in the other 4 cases – p≤0.05. The lowest value level of neutrophilic granulocytes was in rabbits of group No.1 (electric welding). In rabbits of group No. 1 GFBC were not observed in the 8 fields of view throughout the experiment. Conclusions. High-frequency electric welding of soft tissues can be used for effective intraoperative hemostasis and connection of the intraoral wound edges. Due to the absence of a foreign body (adhesive masses, filaments) and moderate alterative effect, histological examination indicates accelerated activation of regenerative processes in the early stages of observation in rabbits of group No. 1.

Electric Welding Vocational Training for Youth in Entrepreneurship

Despiantini (1610631040010). Vocational training of electric welding for youth in Entrepreneurial Training Hall (BLK) Kab. Purwakarta. School of Education Study Program, Faculty of Teacher Training and Education Sciences, University of Singaperbangsa Karawang, 2020.The background of this study was the many unemployment that existed in Kab. Purwakarta which is mainly from the youth circles, and lack of skills among others in electric welding so lost to compete in the workforce. Thus the problem formulation of this research is how the implementation and results of vocational training of electric welding for the youth in entrepreneurship at the Training Hall (BLK) Kab. Purwakarta. The purpose of this research is to obtain an overview of the implementation and outcome of vocational training of electric welding for the youth in Entrepreneurship at the Kab work Training Hall. Purwakarta. The foundations of the theory used in this research include the concept of training. Training is a process of educative interaction between citizens studying with the training components. The training components include: raw input (raw input), instrumental input (input), environmental input, process, output (output), other input, and outcome (influence)... This study used a qualitative approach with a case study method conducted at Kab Training Hall (BLK). Purwakarta. The number of research subjects was five respondents, one organizer, an instructor, and three people. The data collection techniques used in this study are observations, interviews, and documentation analysis. The stages involved in this training include the orientation stage, the exploration stage, and the member check stage.The results of the study as follows: (1) Kab Working Training Hall (BLK). Purwakarta has been conducting vocational training for electrical welding through planning, implementation, and assessment of 28 days of training @ 10 hours lessons/day with 16 people who study trained by one person instructor, and (2) District Training Hall (BLK). Purwakarta has trained 16 people of citizens learn in the mastery of SMAW 2G welding skills in accordance with the prevailing standards. Advice on the implementation of electrical welding vocational training among others so that the BLK can be equipped with electric tools that are still lacking.Keywords: training, welding electricity, entrepreneurship

Industrial science of the tank industry during the Great Patriotic War: contribution to solving problems of engineering and technical optimization of armored production in 1941–1945. Part 2

The work is devoted to the contribution of leading research institutes of the People’s Commissariat of Tank Industry to improve the metallurgical, welding and machining industries in the tank industry of the USSR during the Great Patriotic War. The evacuation of main capacities of the USSR’s tank industry at the east demanded to transfer not only workers and industrial equipment to the base of civil engineering plants, but also to ensure the restoration of key technological processes in a new place. It was required in emergency conditions of war, at a new place, in conditions of personnel, equipment and energy shortage, industrial cooperation collapse, to create workable units, for mass production of tanks. Thanks to the concentration of industry management in the hands of the People’s Commissariat for Tank Industry, the country’s establishment was able to maintain the scientific and technical potential of industrial research institutes that had been engaged in core work in armor metallurgy, electric welding, mechanical processing and mechanical engineering technology before the war. They managed to integrate their personnel and technical potential into the production stuff of tank-building giants, created in the east after the evacuation. It made possible to create under extremely war conditions, a workable territorial production complexes for the production of medium and heavy tanks, which nevertheless got under the conditions of serious personnel and technological limitations.

Evaluation of early healing of postoperative wounds oral mucosa depending on the method of hemostasis and connection of wound edges

Actuality. The final and obligatory stage of each surgical intervention in the oral cavity is the tight connection of the wound edges and ensuring quality hemostasis, in order to prevent postoperative complications and the fastest recovery of tissues. The literature describes various techniques for joining soft tissues, using suture material, staples, fabric adhesive compositions, but due to the emergence of new methods, it is important to compare them. Goal. Compare and evaluate the early stage of healing of postoperative wounds in the oral cavity after open alveolectomy and the use of three methods for hemostasis and connection of wound edges (high-frequency electric welding, suturing nylon 5/0 and N-butyl-2-cyanoacrylate medical adhesive composition). Materials and methods. The study involved 42 patients aged 56 to 83 years, who were in the stage of surgical preparation for prosthetics with removable dentures and required open alveolectomy. Patients with cognitive impairment, cancer, systemic disease, recent acute or long-term chronic cardiovascular and musculoskeletal disorders did not participate in the study. All patients who participated in the study were randomly divided into 3 groups according to the methods of hemostasis and connection of the wound edges. After performing an open alveolectomy, hemostasis and joining of the wound edges were performed. In group 1 (electric welding) consisting of 14 patients, hemostasis and connection of wound edges were performed by welding soft tissues with the device «EKVZ-300M1». In group 2 (suturing) consisting of 14 patients, hemostasis of the wound was performed by connecting its edges with suture material nylon 5/0. In group 3 (adhesive composition) consisting of 14 patients, hemostasis of the wound was performed by joining its edges with a synthetic N-butyl-2-cyanoacrylate medical adhesive composition. Assessment of pain in patients of each group was performed according to the visual-analog scale (VAS). Determination of postoperative wound healing was performed on the basis of the wound healing index according to Landry, Turnbull and Howley. The average time to achieve intra-wound hemostasis and connection of wound edges in each of the groups were determined. The average values of the length of the trapezoidal section in each of the groups were also determined. Results. The analysis of the obtained results showed statistically significant differences (p ≤ 0.05) on the first day in terms of pain sensitivity between groups 2 (sutures) and 3 (glue). On the third day on both indicators (pain and wound healing) between groups 2 and 3 there were no statistically significant differences (p > 0.05). Group 1 (electric welding) has no statistically significant differences in pain sensitivity for the first day with other groups (p > 0.05). Statistically significant differences (p ≤ 0.01) appear on the third day both in terms of pain sensitivity and in terms of wound healing. Conclusions. The method of high-frequency electric welding can be used for intra-wound hemostasis with almost simultaneous connection of the wound edges after open alveolectomy. We found that electric welding has better hemostatic properties, faster connection of wound edges, reduced surgical time, postoperative pain and better results of wound healing compared to suture and adhesive methods. The method of high-frequency electric welding can be an alternative to suture and adhesive methods of hemostasis and joining the edges of the wound oral mucosa after open surgery on the jaws. Key words: oral cavity, mucous membrane, high-frequency electric welding, nylon sutures, adhesive composition, hemostasis, connection, index assessment, oral surgery.