Development of small diameter pilot hole directional drilling for trenchless utility installation

The paper overviews trenchless utility installation techniques and prospects of further development of horizontal directional drilling technology to drill small diameter pilot holes. The improved design is suggested for the thread connection of drill pipes and hydraulic system to generate power pulses

The technology improvement and development of the new design-engineering principles of pilot bore directional drilling

This paper addresses the effectiveness of impact energy use in pilot bore directional drilling at pipe driving. We establish and develop new design-engineering principles for this method. These principles are based on a drill string construction with a new nipple thread connection and a generator construction of strain waves transferred through the drill string. The experiment was conducted on a test bench. Strain measurement is used to estimate compression, tensile, shear and bending stresses in the drill string during the propagation of elastic waves. Finally, the main directions of pilot bore directional drilling improvement during pipe driving are determinated. The new engineering design, as components of the pilot bore directional drilling technology are presented

Drill pipe threaded nipple connection design development

The paper presents the analysis of the behavior of the drill pipe nipple connection under the additional load generated by power pulses. The strain wave propagation through the nipple thread connection of drill pipes to the bottomhole is studied in this paper. The improved design of the nipple thread connection is suggested using the obtained experimental and theoretical data. The suggested connection design allows not only the efficient transmission of strain wave energy to a drill bit but also the automation of making-up and breaking-out drill pipes

Dynamics of bubble rising at small Reynolds numbers

Results of experimental study of a single spherical bubble rising in the non-stationary regime in a viscous liquid (with and without surfactant) at small Reynolds numbers Re<1 have been presented. Improved empirical correlations for drag coefficient of the bubble rising with and without surfactant in the stationary regime have been obtained. Influence of nonstationary effects on the dynamics of bubble rising has been analyzed

Unsteady rise of a bubble in a viscous fluid at small Reynolds numbers

A bubble rising from the state of rest in a viscous incompressible fluid is considered. A formula for the Basset force acting on the bubble in a viscous fluid is obtained, which differs by a multiplier from the Basset force for a solid particle. The problem of unsteady rise of a bubble is solved analytically. The bubble rise is also studied experimentally and the experimental data are compared with the theoretical results

Effect of hydrophobization of airfield coatings on the consumption of deicing reagents2

The issue of reducing costs for the maintenance of airfield coatings is particularly important nowadays due to the increase in the intensity of domestic air transportation. A significant part of the costs of the operational maintenance of airfields is spent on the purchase of deicing reagents (DIR) used to protect airfield pavements from icing. There is a possibility to reduce the required amount DIR by using of hydrophobizing impregnations (HPI) for cement concrete airfield pavements. The assumption about possibility to reduce costs for DIR by using HPI was proven by laboratory tests on specimens of cement concrete slabs. In the course of laboratory tests the process of airfield pavement icing and de-icing was modeled. According to the results of experimental studies it was determined that the consumption of DIR for cement concrete slabs specimens treated with HPI was reduced by 35% compared to similar specimens without HPI treatment. For the economic evaluation of cost reduction for the purchase of DIRs, the costs of applied DIRs used at civil airfields of the Russian Federation were analyzed, taking into account their location in different climatic zones. The assessment has revealed that the cost savings for the purchase of DIRs can be up to 29.1 %

Белковый состав и функциональные показатели мембран эритроцитов при трансплантации печени и почки

Organ transplantation is an effective treatment for many end-stage diseases. However, reperfusion injury constitutes a major complication of transplantation, which is associated with microcirculatory disorders and aggregation of blood corpuscles. Red blood cells (RBC) play an essential role in maintaining hemodynamic and rheological properties of the blood. Moreover, the study of mechanisms of changes in RBC functional indices is an urgent task. The main indicator of RBC functioning is the stability of RBC membrane structure. The issue of RBC membrane modification in organ transplantation has not been studied so far. Objective: to study the protein composition of RBC membranes, their aggregation and electrokinetic parameters in liver and kidney recipients, as well as in related kidney and liver fragment donors before and after operation. Research materials. Blood of 12 kidney recipients and 5 related kidney donors, 8 liver recipients and 4 related liver fragment donors – 1–2 hours before surgery, 1 week, 1, 2, 7, 10, 12 months after surgery. The control group consisted of 8 healthy volunteers. Research methods. Protein separation was done by Laemmli electrophoresis. RBC electrophoretic mobility, which characterizes the electrokinetic properties of cells, was measured by microelectrophoresis. Aggregation was calculated microscopically by counting unaggregated RBCs. Obtained values were compared by Mann-Whitney U test. Results. Examination of the RBC membrane of kidney recipients revealed a significant decrease in the amount of Band 3 protein and glycophorin before and after transplantation. Band 3 protein levels reduced at 1 month, glycophorin reduced at 7 months after surgery, with a maximum decrease in these protein fractions by more than 50% by 7 days compared with control values. There was also a decrease in spectrin content for 2 months after surgery with a maximum decrease of 30% by 1 month. In liver recipients, analysis of RBC membrane proteins revealed a decrease in the amount of glycophorin before surgery and further decrease at 2 months of post-transplant period. The maximum decrease in this index was 72% by 7 days after surgery. In addition, there was a fall in spectrin and Band 3 protein levels at 1 month by more than 60% relative to the control values. In donors, there were changes in the protein fraction of RBC membranes in the long-term post-operative period: spectrin and Band 3 protein levels reduced by 2 times at month 2 in kidney donors, while glycophorin levels reduced by 2.3 times at month 1 after operation in liver donors. Similarly, both groups of donors had increased actin levels at month 1 after surgery. The revealed changes in protein levels in the protein phase of RBC membranes were combined with functional indices of RBCs. In kidney recipients, decreased RBC electrophoretic mobility and increased aggregation were detected at 2 months. In liver recipients, the changes in these indicators were at 1 month. A decrease in RBC electrophoretic mobility was detected in donors of both groups. Conclusion. Changes in RBC membrane electronegativity are associated with changes in glycophorin and Band 3 protein levels, whereas in RBC aggregation process in liver/kidney recipients, the structural and functional disorders in the interrelationships of such membrane proteins as spectrin, Band 3 protein, and glycophorin, are significant factors. Alteration of actin determines inhibition of RBC aggregation growth in donors.Трансплантация органов является эффективным методом лечения пациентов с терминальными стадиями ряда тяжелых заболеваний. Однако серьезным осложнением при трансплантации являются реперфузионные повреждения, которые связаны с микроциркуляторными нарушениями и агрегацией форменных элементов крови. Эритроциты играют существенную роль в поддержании гемодинамических и реологических свойств крови, и изучение механизмов изменения их функциональных показателей является актуальной задачей. Основным показателем функционирования эритроцита служит стабильность структуры мембраны. Вопрос о модификации эритроцитарной мембраны при трансплантации органов на сегодняшний день не исследован.Цель: изучение белкового состава мембран эритроцитов, их агрегационных и электрокинетических показателей у реципиентов печени и почки, а также родственных доноров почки и фрагмента печени до и в динамике послеоперационного периода.Материалы исследования. Кровь 12 реципиентов почки, 5 родственных доноров почки, 8 реципиентов печени и 4 родственных доноров фрагмента печени во временной динамике – за 1–2 часа до операции, через 1 неделю, 1, 2, 7, 10, 12 месяцев после операции. Группу контроля составили 8 здоровых добровольцев.Методы исследования. Разделение белков проводили методом электрофореза по Лэммли. Электрофоретическую подвижность эритроцитов, характеризующую электрокинетические свойства клеток, измеряли методом микроэлектрофореза. Агрегацию рассчитывали микроскопически, путем подсчета неагрегированных эритроцитов. Сравнение полученных величин проводили по U-критерию Манна–Уитни.Результаты. Исследование мембраны эритроцитов крови реципиентов почки выявило значимое снижение количества белка полосы 3 и гликофорина до и после проведения трансплантации. Уровень белка полосы 3 был снижен в течение 1 месяца, гликофорина – в течение 7 месяцев после операции с максимальным уменьшением данных фракций белков более чем на 50% к 7-м суткам относительно значений контроля. Также регистрировалось снижение содержания спектрина в течение 2 месяцев после операции с максимальным снижением на 30% к 1 месяцу. У реципиентов печени анализ белков мембраны эритроцитов выявил снижение количества гликофорина до операции и дальнейшее его уменьшение в течение 2 месяцев посттрасплантационного периода. Максимальное снижение показателя – на 72% – было отмечено к 7-м суткам после операции. Кроме того, наблюдалось снижение количества спектрина и белка полосы 3 в течение 1 месяца более чем на 60% относительно значений контроля. У доноров изменения в белковой фракции эритроцитарных мембран регистрировались в отдаленный период после операции: у доноров почки снижение в 2 раза количества спектрина и белка полосы 3 отмечалось на 2-й месяц, у доноров печени снижение гликофорина в 2,3 раза – к 1-му месяцу после операции. Также в обеих группах доноров регистрировался рост концентрации актина к 1-му месяцу после операции. Выявленные изменения количества белков в белковой фазе эритроцитарных мембран сочетались с функциональными показателями эритроцитов. У реципиентов почки снижение ЭФПЭ и увеличение агрегации наблюдалось в течение 2 месяцев, у реципиентов печени изменения данных показателей зафиксированы в течение 1 месяца. У доноров обеих групп было выявлено уменьшение ЭФПЭ.Заключение. Совокупность полученных результатов показала, что изменение электроотрицательности мембран эритроцитов сопряжено с изменением содержания гликофорина и белка полосы 3, тогда как в процессе агрегации эритроцитов у пациентов после трансплантации печени/почки значимыми факторами являются структурно-функциональные нарушения взаимосвязей таких мембранных белков, как спектрин, белок полосы 3, гликофорин. Изменение актина определяет сдерживание роста агрегации эритроцитов у доноров

«СИНДРОМ ОБКРАДЫВАНИЯ» СЕЛЕЗЕНОЧНОЙ АРТЕРИЕЙ ПОСЛЕ ОРТОТОПИЧЕСКОЙ ТРАНСПЛАНТАЦИИ ПЕЧЕНИ

Splenic artery steal syndrome is one of possible arterial complications after orthotopic liver transplantation. Material includes personal experience in diagnostics and treatment of this syndrome. In each case complication was opportunely suspected basing on laboratory and ultrasound data and proved by angiography. Successful treatment was performed using different variants of splenic artery embolization. Одним из вариантов артериальных осложнений после ортотопической трансплантации печени является синдром обкрадывания селезеночной артерии. В материале представлен собственный опыт диагности- ки и лечения этого состояния. В каждом наблюдении удалось достаточно своевременно заподозрить па- тологический синдром на основании инструментальных и лабораторных данных и подтвердить диагноз при ангиографии. Успешная коррекция выполнена путем различных вариантов эмболизации селезеноч- ной артерии.