Endobronchial valve in complex treatment of patients with drug resistant fibrous cavernous pulmonary tuberculosis

The objective of the study: to assess the efficacy of complex treatment with endobronchial valve implantation in the patients suffering from drug resistant fibrous cavernous pulmonary tuberculosis.Subjects and methods. Treatment outcomes in 97 patients with limited fibrous cavernous pulmonary tuberculosis were analyzed. Main Group included 42 patients who had bronchial valve block implanted. Comparison Group included 55 patients. Artificial pneumoperitoneum was used in both groups.Results. In Main Group, sputum conversion was achieved in 12 months in 40 (95.2%) patients, and in 32 patients (58.2%) in Comparison Group (p < 0.01). In 12 months after treatment start, positive X-ray changes were observed in 42 (100%) patients of Main Group and 40 (72.7%) patients of Comparison Group. Healing of cavities in 12 months was observed only in the patients from Main Group (26 (61.9%) patients). Upon completion of the study, surgery was still indicated to 4 (9.5%) of patients from Main Group and to 35 (63.6%) patients from Comparison Group.

Topology optimization design of hydraulic valve blocks for additive manufacturing

The hydraulic valve block is a core component of an integrated hydraulic system. In practical usage, it exhibits problems such as material waste, long manufacturing cycle, significant energy loss, and leakage. Based on the aforementioned existing problems, this study presents the design of the hydraulic system valve block based on the valve block design principle. The internal valve channel of the hydraulic valve block is optimized for additive manufacturing technology to avoid auxiliary drilling, solve the problem of potential liquid leakage, and shorten the manufacturing cycle. Thus, it is more suitable for the production of customized complex hydraulic valve blocks. The multiobjective topology optimization method is applied to the lightweight design of the hydraulic valve block to save resources and decrease energy consumption. The results indicate that when compared with the original model, the minimum reduction rate of pressure loss in each oil circuit orifice after optimization of the hydraulic valve block corresponds to 32.02%, the maximum corresponds to 71.38%; the maximum stress of the final design corresponds to 542.9 MPa, which satisfies the material strength requirement; and the mass is decreased by 68.9%. Thus, the lightweight design of the hydraulic valve block is realized.

Bench tests of a support system of a powered roof support’s hydraulic leg aimed at minimizing consequences of leaks

Effectiveness of a powered roof support significantly impacts on the efficiency and safety of a mining process. The main element of the support is a hydraulic leg which transfers loads imposed by the rock mass. One of the basic issues occurring during the extraction process are internal and external leaks of hydraulic systems. A new support system was designed to limit and later eliminate the consequences of such leaks. Its main component is a valve block equipped with two independent check valves. This solution allows to maintain high pressure in both chambers of a leg despite leaks. The article discusses the developed solution and presents preliminary results of bench tests of a leg equipped with the new block and loaded dynamically. The results are promising, and the tested block fulfils its task by maintaining the working pressure in the leg during load.