540 Hits in 1.6 sec

Extraction of Independent Structural Images for Principal Component Thermography

Dmitry Gavrilov, Roman Maev
2018 Applied Sciences  
Author Contributions: The presented work was completed under the supervision of Roman Gr. Maev, based on the work of Dmitry Gavrilov.  ... 
doi:10.3390/app8030459 fatcat:fcowyicctfcs5iu2zdwb2srroy

Cold Spray Powders and Equipment [chapter]

Paolo Matteazzi, Alberto Colella, Volf Leshchynsky, Kazuhiko Sakaki, Hirotaka Fukanuma, Roman Maev
2016 Cold Gas Dynamic Spray  
Based on the results of study conducted at many researchers over the world, several type of cold spray equipment 1) have been developed by different companies including ITAM SB RAS(Russia), Kteck corporation (USA), Sulzer Metco(Switzerland), Impact Innovations GmbH (Germany), Plasma Giken Co. Ltd. (Japan), OCPS (Russia) , Centerline (Canada) and others. This section presents a description of the CS equipment, the nozzle design and geometry of cold spray gun. To illustrate the main aspects of
more » ... d spray system parameters determination the numerical simulation and experimental data are presented in Paragraph 3.2.2. A schematic diagram of a cold spray system is shown in Figure 3 .13. Cold spray system consists of the following major components: 1) high pressure gas supply (Nitrogen, helium, air or those mixed gases) 2) gas control module 3) resistive coil gas heater and power supply 4) pre-chamber and supersonic nozzle assembly 5) powder feeder (high-pressure type powder feeder for an axially powder injection (A/I), lowpressure type powder feeder for radially powder injection (R/I) 2 6) process control and data acquisition system 7) robot and its controller. FIGURE 3.13. Schematic diagram of a cold spray system. The process gas is introduced through a gas control module to a manifold system containing a gas heater and powder feeder. The high-pressure gas is heated to a preset temperature, often using a coil of an electrical resistance heated tube. The gas is heated not to heat or soften spray particles but instead to achieve higher sonic flow velocities, which ultimately result in higher particle impact velocities. The high-pressure gas is introduced into the converging section of a de Laval-type nozzle (i. e., a convergent-divergent nozzle, but convergent-divergent-barrel nozzle in Fig.3 .13), the gas is accelerated to sonic in the throat region of the nozzle, and the flow then became supersonic ( Mach numbers ranging from 2 to 4) as it expands in the divergent section of the nozzle 2) . The powder is delivered by a precision metering device called "powder feeder" and typically is injected axially into the center of the highpressure side of the nozzle intake (axial injection of powder: A/I) ( in most case). The powder is accelerated in the divergent and the barrel section of the nozzle, and powder and the gas gush out in the atmosphere and collide with a substrate. And the powder which collided in higher than the critical velocity deposits and forms a coating. One of the major elements of the cold spray process is the high-speed gas jet, which is governed by gas dynamics. In gas dynamics, supersonic flows are obtained with convergent-divergent (or de Laval) nozzles. Thus, in cold spray, the nozzle is one of the most important components. Cold spray process classification 3 Table 3 .3 shows cold spray process classification. As for the current cold spray system, a pressure of the process gas is classified roughly into high pressure types more than 1MPa and two of the following low-pressure types. Furthermore, there is the example which I put CS device in a decompression chamber by a researcher, and calls itself "the vacuum cold spray", but leaves out explanation in the quality dried bonito because I repeat with the aerosol deposition method 3) . Table 3.3. Classification of cold spray process and device. High-pressure/low-temperature gas type shown at (a) in Table3.3 is the first generation CS system with less than approximately 600 o C of process gas temperature at nozzle intake. High-pressure/hightemperature gas type shown at (b) is the second generation CS system with high temperature (1,000 o C) of gas more than (a), and make fireproof metal, such as tantalum and niobium, deposit and improve quality of coating to have improved an adhesion and deposing rate of its coating. The possibility of obtain coating from the WC/Co composition with use of additional preheater of the powder (i,e., increasing its initial temperature at nozzle intake) in CS system of Taekwang tech 5),14) . In (a) the high-pressure/low-temperature type CS system, powder size to use was approximately around 5-50μm, and marketing spray powder was not often available because it was smaller than a commercial powder size distribution for conventional thermal spray. There is Kinetic Spray® (only as for the plot type) which improved this fault by nozzle entrance part extension1). The gas flows in the entrance convergent section of the nozzle exhibit a relatively higher temperature and are subsonic; thus, this region is most suitable for heating spray particles, mentioning it later in # In the second generation commercial high-pressure/high-temperature type CS system (b), the extension of the entrance convergent section of the nozzle and a higher temperature of the process gas became it the 4 relatively bigger particle size was available. In addition, the high pressure portable system (c) in Table 3 .3 was developed for repair in 2009, too. New CS device (SISP: Shock-wave Induced Spray Process) such as an explosion spray device (g) in Table 3 .3 intermittent continuation-shaped a detonation that researchers of Ottawa University developed in 2005, and they continue this work now 17) . In low-pressure types of (d)-(f) in Table 3 .3, Kashirin and colleagues have developed a downstream injection of the powder(R/I) 18) , therefore the powder became able to supply to the nozzle by low pressure, and a high-pressure vessel of powder feeder became needless. However it should be noted that this technique results in a subsonic particle beam hence requires a peening agent to hammer the particles deposited onto the substrate, and to form coating. The low-pressure cold spray process yields coatings of selected ductile materials with acceptable coating characteristics, as compared to the high-pressure process which yields coating of almost any materials with highest coating quality 2) . On the other hand, low temperature high-speed flame spray (HVOF) device (h) ( Table 3 .3) for warm spray process, was developed by researchers 19) at 2000. The temperature of the supersonic gas flow is generated by the combustion of kerosene and oxygen with HVOF flame spray gun which is controlled by diluting the combustion gas with an inert gas such as nitrogen 19) . As for this warm spray, the new model which raised combustion pressure for a further technological advance to 4MPa was developed recently 13) At all events, determination of a shape and the dimensions of the nozzle is very important rather than elevating temperature and pressure of the process gas to accelerate and heat particles efficiently. This nozzle design and geometry will be explained in the next paragraph. 5 Nozzle design and geometry 20)
doi:10.1201/b19486-4 fatcat:lf454biiibf75mgyyeox5falha

Epidemiological and clinical risk factors for non-erosive reflux disease, erosive esophagitis and Barrett's esophagus in Russia

Roman Vasiliev, Igor Maev Igor Maev, Igor Bakulin, Dmitriy Bordin Dmitriy Bordin, Nataliya Bakulina, Inna Oganezova, Ekaterina Skazyvaeva, Maria Skalinskaya, Yulia Embutnieks Yulia Embutnieks, Roman Plavnik, Lyudmila Fedulenkova Lyudmila Fedulenkova, Sergey Tikhonov (+1 others)
2021 Gastroenterology & Hepatology Open Access  
©2021 Maev et al.  ...  Copyright: ©2021 Maev et al.  ... 
doi:10.15406/ghoa.2021.12.00482 fatcat:fnbf536kjrcfppm6hlyklaawku

An Update on Novel Non-Invasive Approaches for Periodontal Diagnosis

Xiaoming Xiang, Michael G. Sowa, Anthony M. Iacopino, Roman G. Maev, Mark D. Hewko, Angela Man, Kan-Zhi Liu
2010 Journal of Periodontology  
.; Maev, Roman G.; Hewko, Mark D.; Man, Angela; Liu, Kan-Zhi Contact us / Contactez nous:  ...  (Reproduced with permission from Maev. 95 )  ... 
doi:10.1902/jop.2009.090419 pmid:20151796 fatcat:heyzqbct4vbhteu7cyrn3hqjse

Correlation between Peel Test and Real Time Ultrasonic Test for Quality Diagnosis in Resistance Spot Welding

Angelo F. Andreoli, Andriy M. Chertov, Roman Gr. Maev
2016 Soldagem & Inspeção  
Abstract: This paper aimed to study the correlation between Real Time Integrated Weld Analyzer measurements and peel test results. The experiment involved study of weld nuggets for different combinations of sheet thicknesses, welding time and current of mild steel samples. The intent was to assess the potential use of a real time integrated ultrasonic system in the industrial environment allowing nondestructive evaluation of 100% of the spot welds produced. The results showed high correlation
more » ... tween nugget penetration into the sheets and nugget size measured ultrasonically and destructively, for all evaluated parameters.
doi:10.1590/0104-9224/si2103.04 fatcat:x64odskwdbdivisti6wjrpbnlm

Time-Frequency Analysis of Clinical Percussion Signals Using Matrix Pencil Method

Moinuddin Bhuiyan, Eugene V. Malyarenko, Mircea A. Pantea, Dante Capaldi, Alfred E. Baylor, Roman Gr. Maev
2015 Journal of Electrical and Computer Engineering  
This paper discusses time-frequency analysis of clinical percussion signals produced by tapping over human chest or abdomen with a neurological hammer and recorded with an air microphone. The analysis of short, highly damped percussion signals using conventional time-frequency distributions (TFDs) meets certain difficulties, such as poor time-frequency localization, cross terms, and masking of the lower energy features by the higher energy ones. The above shortcomings lead to inaccurate and
more » ... guous representation of the signal behavior in the time-frequency plane. This work describes an attempt to construct a TF representation specifically tailored to clinical percussion signals to achieve better resolution of individual components corresponding to physical oscillation modes. Matrix Pencil Method (MPM) is used to decompose the signal into a set of exponentially damped sinusoids, which are then plotted in the time-frequency plane. Such representation provides better visualization of the signal structure than the commonly used frequency-amplitude plots and facilitates tracking subtle changes in the signal for diagnostic purposes. The performance of our approach has been verified on both ideal and real percussion signals. The MPM-based time-frequency analysis appears to be a better choice for clinical percussion signals than conventional TFDs, while its ability to visualize damping has immediate practical applications.
doi:10.1155/2015/274541 fatcat:lon5djz2gnh5fjcs32ppz5sdsy

Experimental Comparative Study of the Applicability of Infrared Techniques for Non-destructive Evaluation of Paintings

Dmitry Gavrilov, Elena Maeva, Oleg Grube, Igor Vodyanoy, Roman Maev
2013 Journal of the American Institute for Conservation  
ROMAN GR. MAEV received combined BS and MSc degrees from the Moscow Engineering Physics Institute in , and PhD from the Physical N. Lebedev Institute of the Russian Academy of Sciences in .  ...  Email: Journal of the American Institute for Conservation , Vol.  No. , -  ... 
doi:10.1179/0197136012z.0000000002 fatcat:o6y3ki4knzb2xh5ztzqhu7vzn4

Reaction assessment of cultured breast cancer cells exposed to anticancer agents using microscale acoustic impedance profile

Rahma Hutami Rahayu, Kyoichi Takanashi, Thomas Tiong Kwong Soon, Inna Seviaryna, Roman Maev, Kazuto Kobayashi, Naohiro Hozumi, Sachiko Yoshida
2018 Japanese Journal of Applied Physics  
The mechanical properties of living cells are known to be associated with disease states and cell function. In this study, acoustic impedance microscopy using a sapphire lens transducer with a center frequency of 320 MHz was employed to characterize the elasticity of the C127I cell line against an anticancer drug, nimustine hydrochloride (ACNU), and an anticancer agent, betulinic acid (BA). Confocal laser scanning microscopy was also used to investigate the drug affecting actin filaments, the
more » ... cleus, and mitochondria structures. Breast cancer cells were found to have significantly lower acoustic impedance after treatment with ACNU and BA than intact cells. Confocal images showed a significant difference in the localization of actin filaments and mitochondria structures, which suggested a difference in cell elasticity. An important insight emerging from this work is that the acoustic impedance of cells may potentially serve as a useful biomarker for anticancer drug efficacy tests, as diseases such as cancer have their own particular mechanical properties.
doi:10.7567/jjap.57.07lf26 fatcat:xcikhywwtjabrhft3quwsog2ji

Genome analysis of E. coli isolated from Crohn's disease patients

Daria V. Rakitina, Alexander I. Manolov, Alexandra V. Kanygina, Sofya K. Garushyants, Julia P. Baikova, Dmitry G. Alexeev, Valentina G. Ladygina, Elena S. Kostryukova, Andrei K. Larin, Tatiana A. Semashko, Irina Y. Karpova, Vladislav V. Babenko (+13 others)
2017 BMC Genomics  
Escherichia coli (E. coli) has been increasingly implicated in the pathogenesis of Crohn's disease (CD). The phylogeny of E. coli isolated from Crohn's disease patients (CDEC) was controversial, and while genotyping results suggested heterogeneity, the sequenced strains of E. coli from CD patients were closely related. Results: We performed the shotgun genome sequencing of 28 E. coli isolates from ten CD patients and compared genomes from these isolates with already published genomes of CD
more » ... ns and other pathogenic and non-pathogenic strains. CDEC was shown to belong to A, B1, B2 and D phylogenetic groups. The plasmid and several operons from the reference CD-associated E. coli strain LF82 were demonstrated to be more often present in CDEC genomes belonging to different phylogenetic groups than in genomes of commensal strains. The operons include carbon-source induced invasion GimA island, prophage I, iron uptake operons I and II, capsular assembly pathogenetic island IV and propanediol and galactitol utilization operons. Conclusions: Our findings suggest that CDEC are phylogenetically diverse. However, some strains isolated from independent sources possess highly similar chromosome or plasmids. Though no CD-specific genes or functional domains were present in all CD-associated strains, some genes and operons are more often found in the genomes of CDEC than in commensal E. coli. They are principally linked to gut colonization and utilization of propanediol and other sugar alcohols.
doi:10.1186/s12864-017-3917-x pmid:28724357 pmcid:PMC5517970 fatcat:zgmqr2go6bfhrory7kzzexi7ni

A Method Based on Muon System to Monitor LHCb Luminosity

Pietro Albicocco, Wander Baldini, Samuel Belin, Valerio Bocci, Nikolay Bondar, Davide Brundu, Sandro Cadeddu, Alessandro Cardini, Maurizio Carletti, Giacomo Chiodi, Alexsei Chubykin, Vladimir Chulikov (+30 others)
2022 Symmetry  
LHCb is one of the four main experiments running at the Large Hadron Collider (LHC) of the European Organization for Nuclear Research. Since 2010, it has been collecting data to study the Physics of b and c quarks. For the past three years, the experimental apparatus underwent significant upgrades to be ready for a new round of data collection, expected to start in June 2022. The new apparatus is designed to be able to run at an instantaneous luminosity five times larger than the previous one,
more » ... hich was 2.0×1032 cm−2s−1, and the whole detector readout will be at a 40 MHz rate. It is worth noticing that the luminosity at the LHCb interaction point, for the characteristics of the detector, needs to be reduced with respect to the luminosity provided by LHC. Major changes in the different subdetectors were required, along with complete modifications of the trigger schemes. The LHCb collaboration is developing and studying different methods for the on-line measurement of luminosity at the LHCb impact point, crucial for the monitoring of correct machine operation and for most experimental physics studies. The present work describes a procedure based on hit counting in the muon detector for an on-line luminosity monitor. The performance and the precision achieved with this method in tests carried out on past data collected are presented, together with proposals for future upgrades.
doi:10.3390/sym14050860 fatcat:bwkddppktvebjfyq52uwkuitfa

Page 43 of Best Sellers Vol. 37, Issue 2 [page]

1977 Best Sellers  
Andrew Greeley, a Roman Catholic priest, sociologist, edu- cator, writer, etc., combines a simple, yet delightful, story line with warmth, wit, and wisdom to deliver his message: God can and should be  ...  Sebi (short for Sebastian) was the clumsiest big dog on the block, but three- year-old Nora Maeve loved him.  ... 

Page 53 of American Catholic Quarterly Review Vol. 31, Issue 121 [page]

1906 American Catholic Quarterly Review  
Maev was, however, soon left a widow, whereupon she journeyed in state to Naas, the  ...  About the time that the Romans conquered Britain there reigned in Ulster a King Fachtna, who was wedded to a beautiful lady named Nessa, by whom he had a son called Conor.  ... 

Mervyn Peake's Letters to Maeve Gilmore

G. Peter Winnington
2013 Peake Studies  
Tom Usborne: The most delightful man with a Roman nose who appears to know everything about everything except Art.  ...  evening': Maeve, Maeve Most precious thing I possess -or ever will.  ... 
doi:10.2478/peakest-2013-0019 fatcat:hick7tdkivdg7kbel45vv7rtqm

Transcriptional regulator PRDM12 is essential for human pain perception

Ya-Chun Chen, Michaela Auer-Grumbach, Shinya Matsukawa, Manuela Zitzelsberger, Andreas C Themistocleous, Tim M Strom, Chrysanthi Samara, Adrian W Moore, Lily Ting-Yin Cho, Gareth T Young, Caecilia Weiss, Maria Schabhüttl (+47 others)
2015 Nature Genetics  
Pain perception has evolved as a warning mechanism to alert organisms to tissue damage and dangerous environments. In humans, however, undesirable, excessive or chronic pain is a common and major societal burden for which available medical treatments are currently suboptimal. New therapeutic options have recently been derived from studies of individuals with congenital insensitivity to pain (CIP). Here we identified 10 different homozygous mutations in PRDM12 (encoding PRDI-BF1 and RIZ homology
more » ... domain-containing protein 12) in subjects with CIP from 11 families. Prdm proteins are a family of epigenetic regulators that control neural specification and neurogenesis. We determined that Prdm12 is expressed in nociceptors and their progenitors and participates in the development of sensory neurons in Xenopus embryos. Moreover, CIP-associated mutants abrogate the histone-modifying potential associated with wild-type Prdm12. Prdm12 emerges as a key factor in the orchestration of sensory neurogenesis and may hold promise as a target for new pain therapeutics.
doi:10.1038/ng.3308 pmid:26005867 pmcid:PMC7212047 fatcat:ohcqxiczl5f77ofwen6dn7t2a4

Manipulation of microspheres and microbubbles in an octagonal sonotweezers

A.L. Bernassau, C.R.P Courtney, J. Beeley, B.W. Drinkwater, D.R.S Cumming
2013 2013 IEEE International Ultrasonics Symposium (IUS)  
Maev ISAF-PFM: David Cann IFCS-EFTF: Jeremy Everard Finance: Herman van de Vaart Debra Coler  ... Publication Chairs: IUS: Jafar Saniie ISAF-PFM: Stanislav Kamba IFCS-EFTF: Aaron Partridge Short Course Chairs: IUS: Roman  ... 
doi:10.1109/ultsym.2013.0485 fatcat:c5gmo27ljrecjbouttiwpahaeu
« Previous Showing results 1 — 15 out of 540 results