232 research outputs found
Hydro and geomechanical stability assessment of the bund wall bottom slope of the Dniprovsk tailing dump
Purpose. The objective is to assess the stability of bund wall components of a hydro-technical structure under the conditions of a tailing dump which hydrodynamic mode has been disrupted during operation. The specified data on the geomechanical state, physical and mechanical properties have been used of both the bund wall material and that of the soil base.
Methods. Mathematical modeling by means of finite element method has been used to assess the hydro and geomechanical stability of bund wall components of a tailing dump (flood-breaking dam). The most reliable software Phase 2 v.8.0 was used for simulating. The modeling takes into consideration the influence of hydrostatic weighing forces and hydrodynamic pressure as well as nonstabilized state of water-logged rocks in the bund wall body.
Findings. Based on the results of assessments, geomechanical stability margin of the bund wall components of a tailing dump has been determined. It has been shown that on an equal height of the bund wall, the areas with insigni-ficant angles of bottom slopes horizontal equivalent are characterized by the greater stability margin, and their
resistance to shear deformation factor is comparable to the strength of alluvial sands shear in the base of a dam. In this context, stability margin is connected with the controlling influence on the bund wall state of water-logged soils, located above the ground water table in the dam body.
Originality. It has been determined that the hydro and geomechanical state of the bund wall components of the
hydro and technical structure is influenced by the occurrence within the bounds of the tailing dump bund wall of alternately water-logged rock material intervals located above the ground water fixed position.
Practical implications. The results of modeling the tailing dump hydro and geomechanical state, which consider the multifactor conditioning of hydrodynamic and deformation processes in a body of the bund wall components, are the basis to substantiate a complex of engineering measures directed at the ensuring further safe operation of the hydro and technical structure.Мета. Оцінка стійкості огороджувальних елементів гідротехнічної споруди в умовах порушеного експлуатацією хвостосховища гідродинамічного режиму на підставі уточнених даних про геомаханічний стан і фізико-механічні властивості матеріалу огороджувальної дамби та ґрунтової основи.
Методика. Для оцінки гідрогеомеханічної стійкості огороджувальних елементів хвостосховища (дамби
обвалування) використано математичне моделювання методом кінцевих елементів за допомогою програмного пакету Phase 2 v.8.0, що враховує вплив сил гідростатичного зважування й гідродинамічного тиску, а також нестабілізованого стану водонасичених порід у тілі огороджувальної дамби.
Результати. За результатами виконаних оцінок встановлено запас геомеханічної стійкості огороджувальних елементів хвостосховища “Дніпровське”. Виявлено, що при рівній висоті огороджувальної дамби великим запасом стійкості характеризуються ділянки з малими кутами закладення низових укосів, а їх опір розвитку зсувних деформацій можна порівняти з опором зрушення алювіальних пісків у основі дамби, при цьому, запас стійкості пов’язаний з визначальним впливом на стан огороджувальної дамби водонасичених ґрунтів, розташованих вище рівня ґрунтових вод у тілі дамби.
Наукова новизна. Встановлено вплив на гідрогеомеханічний стан огороджувальних елементів гідротехнічної споруди наявності в межах огороджувальної дамби хвостосховища інтервалів змінно водонасиченого породного матеріалу, розташованого вище фіксованого положення рівня ґрунтових вод.
Практична значимість. Результати моделювання гідрогеомеханіческого стану дамби хвостосховища, що враховують багатофакторну обумовленість гідродинамічних і деформаційних процесів у тілі огороджуючих елементів, складають основу для обґрунтування комплексу інженерних заходів, спрямованих на забезпечення подальшої безпечної експлуатації гідротехнічної споруди.Цель. Оценка устойчивости ограждающих элементов гидротехнического сооружения в условиях нарушенного эксплуатацией хвостохранилища гидродинамического режима на основании уточненных данных о геомеханическом состоянии и физико-механических свойствах материала ограждающей дамбы и грунтового основания.
Методика. Для оценки гидрогеомеханической устойчивости ограждающих элементов хвостохранилища (дамбы обвалования) использовано математическое моделирование методом конечных элементов с помощью программного пакета Phase 2 v.8.0, учитывающее влияние сил гидростатического взвешивания и гидродинамического давления, а также нестабилизированного состояния водонасыщенных пород в теле ограждающей дамбы.
Результаты. По результатам выполненных оценок установлен запас геомеханической устойчивости ограждающих элементов хвостохранилища “Днепровское”. Выявлено, что при равной высоте ограждающей дамбы большим запасом устойчивости характеризуются участки с малыми углами заложения низовых откосов, а их сопротивление развитию сдвиговых деформаций сопоставимо с сопротивлением сдвигу аллювиальных песков в основании дамбы, при этом, запас устойчивости связан с определяющим влиянием на состояние ограждающей дамбы водонасыщенных грунтов, расположенных выше уровня грунтовых воды в теле дамбы.
Научная новизна. Установлено влияние на гидрогеомеханическое состояние ограждающих элементов гидротехнического сооружения наличия в пределах ограждающей дамбы хвостохранилища интервалов переменно водонасыщенного породного материала, расположенного выше фиксируемого положения уровня грунтовых вод.
Практическая значимость. Результаты моделирования гидрогеомеханического состояния дамбы хвостохранилища, учитывающие многофакторную обусловленность гидродинамических и деформационных процессов в теле ограждающих элементов, составляют основу для обоснования комплекса инженерных мероприятий, направленных на обеспечение дальнейшей безопасной эксплуатации гидротехнического сооружения.The authors express particular gratitude to Oleksandr Boboshko, Chief Engineer of the state enterprise “Barier” for his help while carrying out the research and discussing the results
Combined Transosseous Osteosynthesis of Fracture of Humerus Diaphysis in Case of Reparative Process Disorder (Clinical Observation)
The treatment of the consequences of diaphyseal fractures of the humerus, despite the emergence of modern effective methods of internal osteosynthesis, has not lost its relevance. Transosseous osteosynthesis remains the method of choice in the treatment of pseudoarthrosis and delayed consolidating fractures of the humerus. The experience we have accumulated in the use of external fixation devices in the treatment of fractures, based on the use of the method of unified designation of transosseous osteosynthesis, made it possible to systematize and describe the surgical technique of combined transosseous osteosynthesis in the treatment of fractures of the humerus diaphysis with impaired reparative processes in combination with longitudinal corticotomy of the pseudarthrosis zone, and evaluate its effectiveness. The article presents a case of successful surgical treatment of a patient with a pseudarthrosis of the humerus diaphysis by the method of combined transosseous osteosynthesis in combination with longitudinal corticotomy of the pseudarthrosis zone. A description of the technique of transosseous osteosynthesis is given. The presented clinical case shows that the use of combined transosseous osteosynthesis, taking into account the method of unified designation of transosseous osteosynthesis, makes it possible not only to determine the optimal arrangement of the apparatus and the positions of the transosseous elements, but also to use this method to determine the optimal area for performing longitudinal corticotomy
THE THERAPEUTIC TACTICS OF INTRA-ARTICULAR FRACTURES OF THE ANKLE (LITERATURE REVIEW)
As a result of the analysis of literature it was revealed that in case of pronation-abduction ankle injury takes place injury of the articular surfaces. The hyaline cartilage significantly suffers. Typical localization of damage of the articular cartilage is the middle or front third of the inner edge of talus block. The damage can spread to articular surface of the outer block of the talus. In 50 % cases the articular cartilage is the front edge of the tibia is damaged. The combination of damages of the articular cartilage of the inner edge of the block of the talus and the outside the department anterior edge of the tibia is more often (from 43 % till 57 %). In 80 % cases the damage of the articular cartilage surface of the talus ankle as roughness, cracks, defects with exposure of subchondral bone was revealed. The results say that in case of damage bony and ligamentous structures of the ankle at the joint pronation-abduction mechanism the articular cartilage significantly suffers. The size and character of the damages of the articular cartilage differs. i4s a result we can say that initially severe damage of the articular cartilage at trauma will significantly worsen the immediate and long-term results and this fact should be taken into account while making plan of the treatment of patients with ankle injury
Historical outline on the treatment of patients with chronic posttraumatic instability of shoulder joint (review of literature)
Systematic analysis of literature concerning treatment of patient with chronic posttraumatic instability of shoulder joint in historical aspect was realized. Main tendencies of development of surgical orthopedics including evolution of both palliative and. reconstructive surgical methods for shoulder joint were revealed. On the basis of more than 50 literature sources we managed to estimate progress of scientific researches from the point of view of evidence-based medicine. By the end of 1980s main directions in correction of described nosology which were determined by the level of device-dependent visualization were formed. Necessity of brand new change in mini-invasive surgery of deep and chronic injuries of shoulder joint structures according to the literary data caused, future creation of a new direction based on advanced extended data of pathogenesis of shoulder joint instability
Using an Autograft from the Fibula Diaphysis in the Surgical Treatment of Patients with Fractures of the Proximal Humerus on the Background of Critical Osteoporosis
The frequency of unsatisfactory results of surgical treatment of patients with a fracture of the proximal humerus remains high and is up to 40 %. This is primarily due to the early instability of the metal structure against the background of osteoporosis and as a consequence of non-fusion of the fracture and the formation of a false joint. The aim of the study was to evaluate the effectiveness and safety of a new surgical method for treating patients with a fracture of the proximal humerus against the background of critical osteoporosis. After the approval of the local ethics Committee, 2 groups of 10 patients were formed in the clinic: the patients of main group were operated by the proposed method; the group of clinical comparison was operated by the standard method. In all clinical cases, fractures of the proximal humerus were consolidated on control radiographs. VAS assessment the pain syndrome in the early postoperative period showed that there were no statistically significant differences in the shoulder joint area in the groups. Three months after surgery, when assessing the volume of movement in the shoulder joint (without the participation of the scapula), there was a statistically significant improvement in the main group: abduction – by 35° and external rotation – by 25° (p<0.05). When assessing the range of motion of the operated shoulder joint using the ASES scale, a statistically significant improvement was observed in the main group by 11.6 points after 3 months after surgery. According to the assessment of the patient›s functional recovery according to the DASH scale, the indicators in the main group were statistically significantly better, which indicates a complete recovery of the shoulder joint function. Thus, the use of the proposed new method, in comparison with other known technologies for surgical treatment of fractures of the proximal humerus, allows achieving a more rigid and stable fixation of bone fragments in the aftermath of trauma and the presence of regional osteoporosis
Our experience of surgical treatment of patients with old total injury of rotator cuff tendon
Injury of rotator cuff tendon is a common cause of pain and dysfunction of shoulder joint. The aim. of this study was to evaluate clinical efficiency of surgical treatment of patients with old total rupture of rotator cuff tendon. 63 patients were operated in clinic of Scientific Center of Reconstructive and. Restorative Surgery SB RAMS during 2007—2012. Average age of the patients was 47,6 ±2,1 years. Patients were randomized into two groups of clinical comparison. Patients of the first group had open reinsertion of rotator cuff tendons with transosseous sutures. Patients of the second group had the same procedure with use of an additional metal construction. The observation period differed from 3 months to 5 years (26 ± 5,1 months in average). As the result of the research positive results were in 83,1 % and 82,4 % of cases respectively at the assessment with use of UCLA scale. Reinsertion of full rupture of rotator cuff tendons in spite of risk of trauma of operative treatment is an operation. of choice that gives maximum prospects to the restoration of patients' capability. But analyzed technical defects of known methods caused the creation of a new method of surgical treatment of old injuries of rotator cuff tendon and. the device for its realization
Labour Potential of the Arctic Regions of the European Russia
The work considered the possibilities and directions of evolution of demographic development of the Arctic region, analyzed some characteristics of the labor potential of the population living in the Arctic regions of the European part of Russia.The purpose of the study is to substantiate the possibility of attracting the local population and the need to employment specialists from other regions of Russia for the development of the Arctic.To achieve the goal of the study, general scientifi methods were used — the collection and analysis of data from state statistics and sample surveys. The use of a systematic approach made it possible to comprehensively assess the situation on the territory under study and substantiate the possibilities for its development.Analysis of the quantitative characteristics of the labor potential of the studied regions showed a stable negative dynamics throughout the post-Soviet period. A number of reasons have been identifi that contribute to the outfl of population from the Arctic regions, the most important of which are the low standard of living compared to the Russian average, as well as the ineff functioning of the mechanisms of northern guarantees and compensation. At the same time, the qualitative characteristics of labor potential, in particular, the level of education of the population can be increased due to the existing educational potential of neighboring regions.Conclusions about the need to attract people from the regions of the middle zone of Russia for the Arctic are made
Comparative Determination of the Mechanical Strength of a Transplant from a Tendon of a Semitendinosus Muscle for Plastic Surgery of the Anterior Cruciate Ligament Prepared in Various Ways (Experimental Study)
According to modern literature, a sufficient number of studies have been carried out to determine the mechanical strength of transplants from the tendon of the semitendinous and gracilis muscles, the autologous ligament of the patella, the broad fascia, peroneus longus tendon, each of which has unique characteristics, but at present, transplants prepared by original (new) methods are understudied.In the period from November 5 to December 17,2018 we conducted an experimental study to determine the mechanical strength of a transplant from a tendon of a semitendinosus muscle taken from cadaveric material. The transplants were prepared by original and well-known (Graft-Link technique) methods.The experimental study was approved by the Ethics committee of Irkutsk Scientific Center of Surgery and Traumatology. The material for the study was prepared on the basis of the Irkutsk Regional Bureau of Forensic Medical Examination.After sampling the cadaveric material being studied, the main stages of the experimental study were carried out at the materials resistance department of the Irkutsk State Technical University. Studies of the mechanical properties of the transplant were carried out on a Shimadzu testing machine registered in the State Register of Measuring Instruments and approved for use in the Russian Federation.As a result of the study, we obtained the following data. The mechanical strength of the graft obtained from the tendon of the semitendinosus muscle in an original way is on average 607.8 ± 101.2 N/mm. The mechanical strength of the graft obtained from the tendon of the semitendinosus muscle in a traditional manner (Graft-Link technique) is on average 351.8 ± 133.0 N/ mm
Učinci probiotika koji sadrže Bacillus subtilis na crijevnu mikrofloru, kakvoću žutanjka i koncentracije lipida u krvi prepelica nesilica pasmine faraon
The current literature is not comprehensive concerning the influence of Bacillus subtilis on lipid metabolism, egg chemical characteristics, and intestinal microbiota of Japanese quail. The aim of this study was to evaluate the effects of a Bacillus subtilis strain on yolk quality, gut bacterial populations, and total cholesterol and triglyceride concentrations in the plasma of organically farmed Pharaon quail layers. Forty-five-day-old female quails were randomly distributed into four groups of 10 birds each: a no-treatment control group and three test groups receiving powder of Bacillus subtilis DSM 32424 at a minimum rate of 1 × 106 colony forming units per gram, dissolved in drinking water at doses of 50, 75 and 100 mg per kg body weight, daily during 30 days. The use of the probiotic at doses of 50 and 100 mg resulted in significantly reduced faecal staphylococci count on day 30 (P<0.05), while no significant changes were detected in lactobacilli or coliform bacteria. This study gives the first evidence of the influence of Bacillus subtilis on acid value and carotenoid levels in egg yolks laid by quails. Carotenoids were significantly elevated in the 75 mg group on day 30 (P<0.05), but significantly decreased in the 50 and 100 mg groups (P<0.05). Acidity, triglyceride and total cholesterol concentrations in quail serum were not affected significantly by the treatment throughout the study, though their values were reduced. The inclusion of Bacillus subtilis DSM 32424 in drinking water for laying Pharaon quails inhibited faecal staphylococci proliferation and enhanced yolk carotenoid content. Therefore, it can be proposed that including this probiotic in laying quail diets may have beneficial outcomes for both layers and the second generation.Ovaj rad nije sveobuhvatan obzirom na utjecaj Bacillus subtilis na metabolizam lipida, kemijska svojstva jaja te crijevne mikroorganizme japanskih prepelica. Istraživanje je obavljeno u svrhu procjene učinaka Bacillus subtilis soja na kakvoću žutanjka, populacije bakterija u crijevima uz ukupne koncentracije kolesterola i triglicerida u krvi organski uzgajanih prepelica nesilica pasmine faraon. Četrdesetpetodnevne ženke prepelice nasumice su podijeljene u četiri skupine od po 10 ptica: kontrolnu skupinu koja nije primala dodatak prehrani i tri pokusne skupine koje su primale prašak Bacillus subtilis DSM 32424 pri najmanjem postotku od 1 × 106 jedinica koje stvaraju koloniju po gramu, otopljen u pitkoj vodi u dozama od 50, 75 i 100 mg po kilogramu tjelesne težine, svakodnevno tijekom 30 dana. Uporaba probiotika u dozama od 50 i 100 mg rezultirala je značajnim smanjenjem količine fekalnih stafilokoka na 30. dan (P<0,05), dok značajnije promjene laktobacila i koliformnih bakterija nisu otkrivene. Ovo je istraživanje prvi put pokazalo utjecaj Bacillus subtilis na vrijednost kiseline i razine karotenoida u žutanjcima koje nesu prepelice. Karotenoidi su se značajno podigli na 30. dan u skupini koja je primala 75 mg (P<0,05), ali su se i značajno smanjili u skupinama koje su primale 50 i 100 mg (P<0,05). Terapija nije statistički značajno djelovala na kiselinu. Pokusni dodatak nije značajno utjecao niti na koncentracije triglicerida i ukupni kolesterol u krvi prepelica tijekom ispitivanja, premda su te koncentracije dosta smanjene. Na temelju dobivenih rezultata, zaključeno je da je dodavanje Bacillus subtilis DSM 32424 u pitku vodu za prepelice nesilice pasmine Faraon gotovo na svim proučavanim razinama inhibiralo proliferaciju fekalnih stafilokoka i povećalo udio karotenoida u žutanjku. Stoga se može reći da uključivanje probiotika u prehranu prepelica nesilica može imati korisni učinak i na nesilice i na drugu generaciju
Clinical use of Ortho-SUV transosseous hexapod in treatment of lower limb false joints
We studied the use of Ortho-SUV hexapod in the treatment of 15 patients with lower limb false joints. All patients were at active working age - from 22 to 50 years. 1n 12 patients, the period from the moment of trauma was 1 to 3 years, in 3 patients - 3 to 6 years. 5 patients had femoral false joints, 10 patients - shin false joints. 1n 98 % of cases, the formation of false joints was caused by inadequate treatment of initial trauma. 1n 100 % of cases, false joint localized at diaphyseal level and was accompanied with shortening of injured segment for 2.5 ± 1.0 cm in 13 patients, and for 0.5 and 0.8 cm in 2 cases. We also registered recurvatum and valgus deformity in 5 patients, recurvatum and varus deformity in 8 patients, and antecurvatum and varus deformity in 2 patients. Combined contracture in knee and ankle joint was found in 90 % of patients. Using combined transosseous osteosynthesis along with Ortho-SUV hexapod allowed us to correct hip deformity for 35 ± 10 days and ankle deformity - for 20 ± 5 days on the average. When shortening of femoral bone for more than 5.0 cm, the deformity was corrected in two stages. At the first stage, we reconstructed the length of a segment using methods of transosseous osteosynthesis at discrete-continuum distraction. At the second stage, we corrected deformity using Ortho-SUV hexapod within specified time limits. Duration of femoral and shin false joint consolidation was 194 ± 16 days. We registered inflammatory complications in the areas of transosseous elements contacting soft tissues in 3 (0.2 %) patients. These complications didn't have an effect on the treatment results
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