Modeling of unsteady flow of viscous fluid in the channel of complex geometry

© Published under licence by IOP Publishing Ltd.The article concerns an issue of exploring the mechanism of wave influence on the process of filtration. To describe a filtration flow, the porous medium is represented as a capillary, the radius of which varies sinusoidally. In this article we are presenting the results of numerical modeling of pulsating liquid flow in a sinusoidally-shaped channel. Numerical research was conducted with the help of the program complex FlowVision. As a result of series of calculations we received fields of velocities and pressure in the axial section of flowing channel. It was found that it is the flow in narrow isthmuses between the pores that contributes to the pressure difference the most. We revealed the signs of steady-state liquid flow in the channel when imposing fluctuations of pressure in the absence of pressure gradient. The conditions of formation of such flow are revealed

On the selection of the optimal mode of the wave stimulation in oil production

The work dedicated to the problem mode selection of the wave stimulation to improve the efficiency of oil extraction. The method of combining with wave action by SAGD with two-wellheads reviewed. The process of formation of standing waves in the injection well and the energy propagation of elastic vibrations into a producing reservoir through the wall of the well is investigated. The existence range of the exposure frequency, at which there is minimal absorption of elastic waves, is set. It is shown that with increasing distance from the injection well a value optimum frequency shifts downwards. Obtained results may be the basis for selecting the optimal frequency wave stimulation

Elastic-Wave Effect on Oil Production by In Situ Combustion: Field Results

Copyright © 2015 Taylor & Francis Group, LLC. Elastic vibrations can increase the effectiveness of oil extraction. The most successful results for oil extraction can be achieved by a combination of the elastic-wave action with other methods of enhanced oil recovery. The authors describe field tests of the use of elastic-wave action on an oil recovery process with in situ combustion. The experiment was performed for over five years in various plots of the Mordovo-Karmalskoye oil field. As a result of this combination, oil production was increased, water cut recoverable products were decreased, and unit costs were decreased. Physical mechanisms are proposed to explain this phenomenon

Intensification of oil production under vibration impact on the producing formation

Improving the efficiency of oil field development is possible due to the intensification of oil production by a vibrating impact on producing formation. Numerous laboratory and field research confirm this. Intensification of oil production is due to the many phenomena occurring in the productive strata at imposing elastic vibrations. Selecting the desired frequency of formation stimulation in this case is one of the important issues. The essence of the proposed idea is that the frequency of vibrating influence should be chosen close to the natural frequencies of noise filtration of producing formation. This paper investigates the spectra of noise filtration of samples of artificial and natural porous media. We present some results of the impact of elastic vibrations on the producing formation. It is shown that a greater effect in the oil production achieved at frequencies close to the frequency of noise filtration

Computer simulation of electron-positron pair production by channeling radiation in amorphous converter

We consider the radiator-converter approach at 200 MeV channeled electrons (the SPARC_LAB LNF facility energies) for the case of using W crystalline radiator and W amorphous converter. A comparison of the positron production by the axial channeling radiation and the bremsstrahlung is performed. The positron stopping in the convertor is studied by means of computer simulations. It is shown that for the maximum yield of positrons the thickness of the W amorphous converter should be taken 0.35 cm in the case of using the axial channeling radiation resulting to total yield of positrons 5 10-3 e+/e- and 0.71 cm in the case of using the bremsstrahlung resulting to total yield of positrons 3.3 10-3 e+/e-

Spectral characteristics of acoustic emission in porous media

Acoustic emission occurs when solid media are subjected to mechanical load and deformation. The porous medium also experiences strain when creating a pressure gradient fluid. The experimentally found that the generation of noise filtration is different from the nature of the acoustic emission caused by purely mechanical loading. The amplitude of the noise filtering is dependent on the flow rate, and the frequency determined by the properties of the porous medium (porosity, permeability, fractional composition, etc.), that is independent of the fluid flow regime. Analysis of the spectra of noise filtration for all the studied artificial samples showed a pattern of increasing the frequency of the major peaks in the spectrum with increasing permeability of the porous medium. The results obtained and identified patterns can be used in solving the problems of identification of Applied Geophysics, and the implementation of wave methods of enhanced oil recovery

Alpha Channeling in a Rotating Plasma

The wave-particle alpha-channeling effect is generalized to include rotating plasma. Specifically, radio frequency waves can resonate with alpha particles in a mirror machine with ExB rotation to diffuse the alpha particles along constrained paths in phase space. Of major interest is that the alpha-particle energy, in addition to amplifying the RF waves, can directly enhance the rotation energy which in turn provides additional plasma confinement in centrifugal fusion reactors. An ancillary benefit is the rapid removal of alpha particles, which increases the fusion reactivity.Comment: 4 pages and 3 figure

Обзор существующих методик оценки активности CYP2D6 с применением экзогенных и эндогенных маркеров

Peculiarities of functioning and polymorphism of cytochrome P450 isoenzyme CYP2D6. Existing methods for determining its activity using endogenous markers. A review of studies on the screening of endogenous substrates, biotransformation mainly under the influence of isoenzyme CYP2D6. The results by determination pinoline relationship to its metabolite 6-hydroxy-1,2,3,4-tetrahydro-beta-carboline in vitro in cell culture and in vivo in mice for evaluation isoenzyme activity CYP2D6.Приведены особенности функционирования и полиморфизма изофермента цитохрома Р450 CYP2D6. Рассмотрены существующие методики определения его активности при помощи эндогенных маркеров. Представлен обзор исследований по скринингу эндогенных субстратов, подвергающихся биотрансформации преимущественно под воздействием изофермента CYP2D6. Изложены результаты по определению отношения пинолина к его метаболиту 6-гидрокси-1,2,3,4-тетрагидро-бета-карболину in vitro на культуре клеток и in vivo на мышах для последующей оценки активности изофермента CYP2D6

Влияние изофермента CYP2D6 на метаболизм лекарственных препаратов и методы определения его активности

The article presents relevant information on the features of cytochrome P450 isoenzyme CYP2D6 functioning. 20-25% of drugs are metabolized by the action of CYP2D6. Determination of its activity allows for adjusting pharmacotherapy to increase the efficacy and safety of a drug or a combination of drugs. Cytochrome P450 isoenzymes genotyping and phenotyping methods allow for choosing the dosage and dosing regimen for patients on an individual basis. This article describes the genetic characteristics affecting CYP2D6. CYP2D6 polymorphism has a significant impact on pharmacokinetics and metabolism of a drug. This may lead to side effects, or decrease the pharmacological action of the drug. The article covers the cases of change in clinical response to receiving β-blockers (metoprolol), antidepressants (venlafaxine) and opioids (codeine). These changes occurred in the presence of certain CYP2D6 alleles which speed up or slow down the metabolism. It also provides information on drug-drug interactions involving inhibition of cytochrome P450 isoenzyme CYP2D6. Genotyping methods are used to determine the potential activity of CYP2D6. Dose adjustment is carried out basing on the results obtained. The current isoenzyme status is defined by phenotyping methods. CYP2D6 activity can be evaluated by determining the ratio of the substrate and its metabolite using HPLC. Pinoline, which is metabolized to 6-hydroxy-1,2,3,4-tetrahydro-β-carboline, is the endogenous substrate for estimating the activity of CYP2D6.В статье приведена актуальная информация об особенностях функционирования изофермента цитохрома Р450 CYP2D6. Метаболизм 20-25% лекарственных препаратов происходит под действием изофермента CYP2D6. Определение его активности позволяет скорректировать фармакотерапию с увеличением эффективности и безопасности препарата или комбинации препаратов. Методы генотипирования и фенотипирования изоферментов цитохрома Р450 позволяют индивидуально для пациента подбирать дозировку, режим дозирования. В статье описаны генетические особенности, которые оказывают воздействие на изофермент CYP2D6. Полиморфизм изофермента CYP2D6 оказывает существенное влияние на метаболизм и фармакокинетику лекарственного препарата, что может привести кпобочным эффектом или снижению фармакологического действия препарата. Рассмотрены случаи изменения клинического ответа на прием β-блокаторов (метопролол), антидепрессантов (венфлаксин) и опиоидов (кодеин). Данные изменения происходили при наличии определенных аллелей CYP2D6, которые ускоряют или замедляют метаболизм. Также представлена информация о межлекарственном взаимодействиях, при которых происходит ингибирование изофермента цитохрома Р450 CYP2D6. Для определения потенциальной активности изофермента CYP2D6 используются методы генотипирования. На основании полученных результатов, проводится корректировка дозы. Текущий статус изофермента определяется методами фенотипирования. Определение соотношения субстрата и его метаболита методом высокоэффективной жидкостной хроматографии позволяют произвести оценку активности изофермента. Эндогенным субстратом для определения активности изофермента CYP2D6 является пинолин, метаболитом которого является 6-гидрокси-1,2,3,4-тетрагидро-β-карболин