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Texture,composition and properties of plugs formed by carbon dioxide hydrate and wax

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Petroleum exploration and Development 2021年第6期48卷 1462-1470页

作者： SKIBA Sergey SAGIDULLIN aleksey SHAPOVALOVA Alexandra STReLeTS Larisa MANAKOV Andrey Nikolaev Institute of Inorganic Chemistry SB RASAc.Lavrentiev Ave.3Novosibirsk 630090Russia Novosibirsk State University Pirogova Str.2Novosibirsk 630090Russia Institute of Petroleum Chemistry SB RAS Akademichesky ave.4Tomsk 634021Russia

Gas hydrates and wax are the major flow assurance problems for the transportation of produced hydrocarbons through ***,in most research works both these two problems are studied *** simultaneous precipitation or deposition of these compounds in pipelines can lead to different mitigation/prevention strategies,the investi-gations in which both these problems are considered simultaneously appeared only *** is no information in the literature on the texture/composition and features of decomposition process of mixed wax/hydrate *** the same time,this information could be useful to understand how to treat the problem of formation of these *** this work,three wax/gas hydrate plugs were collected at quasi-static conditions from a water-in-oil emulsion to study their texture,composition and the features of decomposition *** X-ray diffraction and IR(infrared spectroscopy)analyses showed that the plugs consisted of wax and gas *** and DSC(Differential Scanning Calorimetry)experiments showed that the main part of gas hydrate in the plugs at the ambient pressure started to decompose at about 268 *** temperature was higher than the equilibrium temperature of carbon dioxide hydrate at this pressure,indicating that the gas hydrate in the plugs could be effectively preserved at temperatures below the ice melting point(273.2 K).It was found through observation of the hydrate decomposition process in the plugs under the microscope that the gas in the samples released in small bubbles,while the hydrate particles were not visible at this magnification,indicating that the hydrate was indeed highly dispersed in the samples.A residual wax was jelly-like after decomposition of hydrate in all the *** experiments showed that the plugs residues after decomposition of the hydrates had higher yield points and viscosities than the initial waxy crude oil origi-nally used for the experiments.

关键词： carbon dioxide hydrate hydrate/wax plug plug texture hydrate decomposition

Semi-Markovian Model of Monotonous System Maintenance with Regard to Operating Time to Failure of each element

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Intelligent Information Management 2010年第8期2卷 447-456页

作者： Yuriy e. Obzherin aleksey I. Peschansky 不详

An explicit form of reliability and economical stationary performance indexes for monotonous multicomponent system with regard to its elements’ maintenance has been found. The maintenance strategy investigated supposes preventive maintenance execution for elements that has attained certain operating time to failure. Herewith for the time period of elements’ maintenance or restoration operable elements are not deactivated. The problems of maintenance execution frequency optimization have been solved. For the model building the theory of semi-Markovian processes with a common phase field of states is used.

关键词： Maintenance Semi-Markovian Process System Stationary Characteristics System Performance Indexes Optimization

Semi-Markovian Model of Monotonous System Maintenance with Regard to its elements’ Deactivation and Age

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Applied Mathematics 2010年第3期1卷 234-243页

作者： Yuriy e. Obzherin aleksey I. Peschansky 不详

An explicit form of reliability and economical stationary performance indexes for monotonous multicomponent system with regard to its elements’ maintenance has been found. The maintenance strategy investigated supposes preventive maintenance execution for elements that has attained certain operating time to failure. Herewith for the time period of elements’ maintenance or restoration operable elements, functionally connected with the failed ones, are deactivated. The problems of maintenance execution frequency optimization have been solved. For the model building the theory of semi-Markovian processes with a common phase field of states is used.

关键词： Maintenance Semi-Markovian Process System Stationary Characteristics System Performance Indexes Optimization

Multi-Drug Resistance Pattern of Lactose Non-Fermenting escherichia colias Causative Agent of Urine Tract Infections in Luanda, Angola

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Open Journal of Medical Microbiology 2019年第1期9卷 1-7页

作者： aleksey Shatalov Laboratory of Microbiology at Luanda Medical Center Luanda Angola

This prospective study was carried out to assess the sensitivity and resistance pattern of lactose non-fermenting escherichia coli from July 2018 to December 2018 in the Laboratory of Microbiology at Luanda Medical Center, Angola. Out of 1170 patient, a total of 120 urine specimens infected with escherichia coli (>105 CFU/ml) were collected according to the routine protocol of urinalysis. Among these 120 isolates, 25 (21%) isolates were determined as “atypical”, lactose non-fermenting e. colis trains. The twenty-five lactose non-fermenting escherichia coli strains isolated from urine samples in Luanda Medical Center were declared as Multiple Drugs-Resistant strains with high resistance to Cefalexine (100%), Cefuroxime (100%), Ceftriaxone (92%), Gentamycin (92%), Ciprofloxacin (72%) and Amoxiciclin/Clavulanic (80%). The alarming resistance level to the first-choice drugs for the treatment of urinary tract infections caused by non-fermentative lactose e. coli was observed.

关键词： escherichia coli Multi-Drugs Resistance (MDR) Lactose Non-Fermenting Urine Tract Infections Colony Forming Unit (CFU)

Prevalence and Antibiotic Resistance Pattern of escherichia coliand Klebsiella pneumoniaein Urine Tract Infections at the La Paz Medical Center, Malabo, equatorial Guinea

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Open Journal of Medical Microbiology 2015年第4期5卷 177-183页

作者： aleksey Shatalov Laboratory of La Paz Medical Center Malabo Equatorial Guinea

The study was conducted to isolate and determine the antibiotic resistance in escherichia coli and Klebsiella pneumonia from urine samples over a 2-year period (August 2013-September 2015) at the La Paz Medical Center, Malabo. A retrospective analysis of 785 urine culture samples over a 2-year period August 2013-September 2015 was carried out according to the routine protocol of urinalysis. Bacterial etiological agents were isolated from 155 (19.7%) samples with highest prevalence of escherichia coli (55.5%) followed by Klebsiella pneumonia (23.2%), Proteus mirabilis (4.5%), Pseudomonas species (3.2%), enterobacter species (2.6%), enterococcus faecalis (2.6%) and others species (8.4%). The e. coli and K. pneumonia represent 78.7% of all isolated bacterial strains. The e. coli and K. pneumoniae isolates possess highly resistant to ampicillin, Trimethoprim/Sulfamethoxazole, Doxycycline, Amoxicicline/Clavulanic acid. Whereas K. pneumonia demonstrated also to be highly resistant to Gentamycin, Cefuroxime and Ceftriaxon, low level of resistance to Piperacilin/Tazobactam, Amikacin and the lowest to Imipenem. The alarming level of MDR strains to the first choice antibiotics treatment was observed.

关键词： Urine Tract Infections Antibiotic Resistance Klebsiella pneumonia escherichia coli

A Study of New Nondispersive SH-SAWs in Magnetoelectroelastic Medium of Symmetry Class 6 mm

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Open Journal of Acoustics 2015年第3期5卷 95-111页

作者： aleksey Anatolievich Zakharenko International Institute of Zakharenko Waves (IIZWs) Krasnoyarsk Russia

Two additional solutions of new shear-horizontal surface acoustic waves (SH-SAWs) are found in this theoretical report. The SH-SAW propagation is managed by the free surface of a solid when it has a direct contact with a vacuum. The studied smart solid represents the transversely isotropic piezoelectromagnetic (magnetoelectroelastic or Mee) medium that pertains to crystal symmetry class 6 mm. In the developed theoretical treatment, the solid surface must be mechanically free. Also, the magnetic and electrical boundary conditions at the common interface between a vacuum and the solid surface read: the magnetic and electrical displacements must continue and the same for the magnetic and electrical potentials. To obtain these two new SH-SAW solutions, the natural coupling mechanisms such as eμ-hα and εμ-α2 present in the coefficient of the magnetoelectromechanical coupling (CMeMC) can be exploited. Based on the obtained theoretical results, it is possible that a set of technical devices (filters, sensors, delay lines, lab-on-a-chip, etc.) based on smart Mee media can be developed. It is also blatant that the obtained theoretical results can be helpful for the further theoretical and experimental studies on the propagation of the plate SH-waves and the interfacial SH-waves in the Mee (composite) media. The most important issue can be the influence of the magnetoelectric effect on the SH-wave propagation. One must also be familiar with the fact that the surface, interfacial, and plate SH-waves can frequently represent a common tool for nondestructive testing and evaluation of surfaces, interfaces, and plates, respectively.

关键词： Piezoelectromagnetic Medium Magnetoelectric effect New Shear-Horizontally Polarized SAWs

The Master equation and the Pauli equation in the Fuzzy Time Model

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Journal of Applied Mathematics and Physics 2018年第2期6卷 358-372页

作者： aleksey M. Avdeenko Department of Information Technology The National Research Technological University Moscow Russia

The approach proposed in the study is based on the revision of the concept of time as a point on the real axis. It uses the concept of fuzzy time as the set of real numbers with a finite, but not equal to one, function of membership to the time set, i.e. the fuzzy time concept. It is postulated that in fuzzy time t the system dynamics follows from the standard variational principle of the least action and is ordinary Hamilton-Jacobi mechanics. This validates the passage to the limit from fuzzy mechanics to ordinary variational conservative mechanics. The Liouville equation is solved by the method of successive approximations in the time domain of a much larger characteristic scale of fuzziness, using interaction as a small parameter. A standard diagram technique is used. It can be shown that the defuzzification of the Liouville equation inevitably reduces the reversible part in the description to the irreversible evolutionary equation. The latter leads to the second law of thermodynamics. Generalization to the quantum case is possible, i.e. the so-called fuzzy Pauli equation can be drawn.

关键词： Fuzzy Sets Fuzzy Time Master equation Second Law of Ther-modynamics Fuzzy Pauli equation

Semi-Markovian Model of Control of Restorable System with Latent Failures

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Applied Mathematics 2011年第3期2卷 383-388页

作者： Yuriy e. Obzherin aleksey I. Peschansky Yelena G. Boyko 不详

Mathematical model of control of restorable system with latent failures has been built. Failures are assumed to be detected after control execution only. Stationary characteristics of system operation reliability and efficiency have been defined. The problem of control execution periodicity optimization has been solved. The model of control has been built by means of apparatus of semi-Markovian processes with a discrete-contin- uous field of states.

关键词： Control Latent Failure Semi-Markovian Process System Stationary Characteristics

economy of energy during Refrigerating Machine Operation

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Journal of Mechanics engineering and Automation 2016年第5期6卷 265-268页

作者： Aleksandr Vasserman aleksey Slyn'ko Odessa National Maritime University Odessa Ukraine