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Acoustic emission characterization of microcracking in laboratory-scale hydraulic fracturing tests

Journal of Rock Mechanics and Geotechnical Engineering 2018年第5期10卷 805-817页

作者： Jesse Hampton Marte Gutierrez Luis Matzar Dandan Hu luke Frash Department of Civil & Environmental Engineering Colorado School of Mines Golden CO 80401 USA New England Research Inc. White River Junction VT 03766 USA Halliburton Houston TX 77032 USA Los Alamos National Laboratory Los Alamos NM 87545 USA

Understanding microcracking near coalesced fracture generation is critically important for hydrocarbon and geothermal reservoir characterization as well as damage evaluation in civil engineering structures. Dense and sometimes random microcracking near coalesced fracture formation alters the mechanical properties of the nearby virgin material. Individual microcrack characterization is also significant in quantifying the material changes near the fracture faces （i.e. damage）. Acoustic emission （AE） monitoring and analysis provide unique information regarding the microcracking process temporally, and infor- mation concerning the source characterization of individual microcracks can be extracted. In this context, laboratory hydraulic fracture tests were carried out while monitoring the AEs from several piezoelectric transducers. In-depth post-processing of the AE event data was performed for the purpose of under- standing the individual source mechanisms. Several source characterization techniques including moment tensor inversion, event parametric analysis, and volumetric deformation analysis were adopted. Post-test fracture characterization through coring, slicing and micro-computed tomographic imaging was performed to determine the coalesced fracture location and structure. Distinct differences in fracture characteristics were found spatially in relation to the openhole injection interval. Individual microcrack AE analysis showed substantial energy reduction emanating spatially from the injection interval. It was quantitatively observed that the recorded AE signals provided sufficient information to generalize the damage radiating spatially away from the injection wellbore.

关键词： Acoustic emission (AE) Microcracking Hydraulic fracturing Laboratory-scale testing Moment tensor analysis Fracture coalescence Computed tomography (CT) imaging

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GENERALIZED RAY APPROXIMATE METHOD TO INVERSE MEDIUM PARAMETERS

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Acta Mechanica Solida Sinica 1996年第1期9卷 59-65页

作者： Niu, YQ Du, DS Ma, XG Huang, wh HARBIN INST TECHNOL DEPT ASTRONAUT & MECHHARBIN 150001PEOPLES R CHINA HARBIN INST TECHNOL DEPT ASTRONAUT & MECHHARBIN 150001PEOPLES R CHINA

In this paper, the inverse problem of the medium parameters in an inhomogeneous medium is studied and a generalized ray approximate form of the total wave field is described. First, the acoustic wave equation derived from the elastic wave equation is studied, the referential variables and perturbational variables are introduced, and the integral equation of the medium perturbational parameters is obtained. Then from the point of view of the local principles of the wave function in an inhomogeneous medium, a generalized ray approximate form of the total wave field in an inhomogeneous medium is described, and attention is focused on the Fredholm integral equation of the first kind. Finally, the medium parameters in half-plane are inversed. Numerical examples show when the perturbations of the medium parameters are about 0.5, this method can effectively inverse its variation. Apparently, this method is better than the conventional Born weak scattering approximation.

关键词： integral equation generalized ray approximation medium parameters function integral transform

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Mouse models in liver cancer research:A review of current literature

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World Journal of Gastroenterology 2008年第45期14卷 6915-6923页

作者： Martijn wh Leenders Maarten W Nijkamp Inne HM Borel Rinkes Department of Surgery University Medical Center Utrecht

Primary liver cancer remains one of the most lethal malignancies worldwide. Due to differences in prevalence of etiological factors the incidence of primary liver can-cer varies among the world, with a peak in East-Asia. As this disease is still lethal in most of the cases, research has to be done to improve our understanding of the disease, offering insights for possible treatment options. For this purpose, animal models are widely used, especially mouse models. In this review, we describe the different types of mouse models used in liver cancer research, with emphasis on genetically engineered mice used in this field. We focus on hepatocellular carcinoma (HCC), as this is by far the most common type of primary liver cancer, accounting for 70%-85% of cases.

关键词： Primary liver cancer Hepatocellular carcinoma Mouse model Genetically engineered mice

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Removal of heavy metals from mine water by cyanobacterial calcification

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Mining Science and Technology 2010年第4期20卷 566-570页

作者： DONG Donglin LI Hongjiang ZHANG Jie SUN luke State Key Laboratory of Coal Resources and Safe Mining China University of Mining&TechnologyBeijing 100083China

The influence of different illumination intensities on cyanobacterial calcification induced removal of heavy metals from contaminated mine water was studied. Cyanobacterial calcification experiments were performed using a growth medium intended to simulate contaminated mine water. The results indicate that calcification can promote the removal of heavy metal ions. As the illumination intensity became stronger calcification rates increased and the removal of Zn2+ and Cd2+ became more obvious. when the illumination intensity was 10000 lux the removal of Pb2+ was the largest observed: stronger or weaker illumination reduced the amount of lead removed. The removal of three different heavy metals complies with an index function. For identical illumination intensities different ions were removed to different degrees.

关键词： coal mine cyanobacteria calcification heavy metal illumination intensity removal

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Bioinspired optical antennas: gold plant viruses

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Light(Science & Applications) 2015年第1期4卷 447-453页

作者： SoonGweon Hong Mi Yeon Lee Andrew O Jackson luke P Lee Department of Bioengineering University of California at BerkeleyBerkeleyCA 94720USA Berkeley Sensor and Actuator Center University of California at BerkeleyBerkeleyCA 94720USA Department of Plant&Microbial Biology University of California at BerkeleyBerkeleyCA 94720USA Department of Electrical Engineering and Computer Sciences University of California at BerkeleyBerkeleyCA 94720USA Biophysics Graduate Program University of California at BerkeleyBerkeleyCA 94720USA

The ability to capture the chemical signatures of biomolecules(i.e.,electron-transfer dynamics)in living cells will provide an entirely new perspective on biology and *** can be accomplished using nanoscale optical antennas that can collect,resonate and focus light from outside the cell and emit molecular ***,we describe biologically inspired nanoscale optical antennas that utilize the unique topologies of plant viruses(and thus,are called gold plant viruses)for molecular fingerprint *** electromagnetic calculations for these gold viruses indicate that capsid morphologies permit high amplification of optical scattering energy compared to a smooth *** experimental measurements of various gold viruses based on four different plant viruses,we observe highly enhanced optical cross-sections and the modulation of the resonance wavelength depending on the viral ***,in label-free molecular imaging,we successfully obtain higher sensitivity(by a factor of up to 10^(6))than can be achieved using similar-sized *** virtue of the inherent functionalities of capsids and the plasmonic characteristics of the gold layer,a gold virus-based antenna will enable cellular targeting,imaging and drug delivery.

关键词： molecular sensor nanophotonics optical antenna optical spectroscopy plant virus plasmonics plasmonic resonant energy transfer(PRET) surface enhanced Raman scattering(SERS)

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Retrieval of dislodged AmplifEYE using balloon dilator during colonoscopy

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Gastroenterology Report 2019年第2期7卷 139-140,I0002页

作者： Jihui Li luke Blake Steven D.Wexner Department of General Surgery Paris Community HospitalParisILUSA Department of Colorectal Surgery Cleveland Clinic FloridaWestonFLUSA

AmplifEYE can increase the detection rate of adenomatous polyps and stabilize the mucosa for easy biopsy and *** it can also become a foreign body when it is dislodged during the *** report a case of dislodged AmplifE... 详细信息

关键词： colonoscopy AmplifEYE foreign-body retrieval balloon dila

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Automated bolting and meshing on a continuous miner for roadway development

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International Journal of Mining Science and Technology 2013年第1期23卷 55-61页

作者： van Duin Stephen Meers luke Donnelly Peter Oxley Ian University of Wollongong Northfields Avenue Gwynneville NSW Australia

Automated installation of primary roof support material can potentially increase productivity and operator safety in the roadway development process within underground coal mining. Although the broader manufacturing sector has benefited from automation, several challenges exist within the Australian underground coal industry which makes it difficult to fully exploit these technologies. At the University of Wollongong a series of reprogrammable electromechanical manipulators have been designed to overcome these challenges and automatically handle the installation of roof and rib containment consumables on a continuous miner. The automated manipulation removes personnel from hazards in the immediate face area, particularly those associated with working in a confined and unstable working environment in close proximity to rotating and moving equipment. In a series of above ground trials the automated system was successfully demonstrated without human intervention and proven to be capable of achieving cycle times at a rate of 10 m per operating hour, consistent with that required to support high capacity longwall mines. The trials also identified a number of refinements which could further improve both cycle times and system reliability when considering the technology for underground use. The results have concluded that conventional manual handling practices on a continuous miner can be eliminated, and that the prototypes have significantly reduced the technical risk in proceeding to a full underground trial.

关键词： Automation Robotics Roadway development Manipulation Roof support

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A systematic review and meta-analysis to determine the effect of sperm DNA damage on in vitro fertilization and intracytoplasmic sperm injection outcome

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Asian Journal of Andrology 2017年第1期19卷 80-90页

作者： luke Simon Armand Zini Alina Dyachenko Antonio Ciampi Douglas T Carrell Department of Surgery (Urology) University of Utah School of Medicine Salt Lake City UT USA Division of Urology Department of Surgery St. Mary's Hospital Center St. Mary's Hospital 3830 Lacombe Avenue Montreal Quebec H3T 1M5 Canada Department of Human Genetics University of Utah School of Medicine Salt Lake City UT USA Department of Obstetrics and Gynecology University of Utah School of Medicine Salt Lake City UT USA.

Sperm DNA damage is prevalent among infertile men and is known to influence natural reproduction. However, the impact of sperm DNA damage on assisted reproduction outcomes remains controversial. Here, we conducted a meta-analysis of studies on sperm DNA damage （assessed by SCSA, TUNEL, SCD, or Comet assay） and clinical pregnancy after IVF and/or ICSI treatment from MEDLINE, EMBASE, and PUBMED database searches for this analysis. We identified 41 articles （with a total of 56 studies） including 16 IVF studies, 24 ICSI studies, and 16 mixed （IVF ＋ ICSI） studies. These studies measured DNA damage （by one of four assays： 23 SCSA, 18 TUNEL, 8 SCD, and 7 Comet） and included a total of 8068 treatment cycles （3734 IVF, 2282 ICSI, and 2052 mixed IVF ＋ ICSI）. The combined OR of 1.68 （95% Ch 1.49-1.89; P 〈 0.0001） indicates that sperm DNA damage affects clinical pregnancy following IVF and/or ICSI treatment. In addition, the combined OR estimates of IVF （16 estimates, OR = 1.65; 95% CI： 1.34-2.04; P 〈 0.0001）, ICSI （24 estimates, OR = 1.31; 95% Ch 1.08-1.59; P = 0.0068）, and mixed IVF ＋ ICSI studies （16 estimates, OR = 2.37; 95% Ch 1.89-2.97; P〈 0.0001） were also statistically significant. There is sufficient evidence in the existing literature suggesting that sperm DNA damage has a negative effect on clinical pregnancy following IVF and/or ICSI treatment.

关键词： assisted reproductive technology outcomes clinical pregnancy meta-analysis sperm DNA damage systematic review

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RFID Adaption in Healthcare Organizations:An Integrative Framework

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Computers, Materials & Continua 2022年第1期70卷 1335-1348页

作者： Ahed Abugabah Louis Sanzogni luke Houghton Ahmad Ali AlZubi Alaa Abuqabbeh College of Technical Innovation Zayed UniversityAbu DhabiUAE Nathan Campus Griffith UniversityAustralia Department of Computer Science King Saud UniversityRiyadhSaudi Arabia Golden Gate University San FranciscoCaliforniaUSA

Radio frequency identification(RFID),also known as electronic label technology,is a non-contact automated identification technology that recognizes the target object and extracts relevant data and critical characteristics using radio frequency *** equipment information management is an important part of the construction of a modern hospital,as it is linked to the degree of diagnosis and care,as well as the hospital’s benefits and *** aim of this study is to create an integrated view of a theoretical framework to identify factors that influence RFID adoption in healthcare,as well as to conduct an empirical review of the impact of organizational,environmental,and individual factors on RFID adoption in the healthcare *** contrast to previous research,the current study focuses on individual factors as well as organizational and technological factors in order to better understand the phenomenon of RFID adoption in healthcare,which is characterized as a dynamic and challenging work *** research fills a gap in the current literature by describing how user factors can influence RFID adoption in healthcare and how such factors can lead to a deeper understanding of the advantages,uses,and impacts of RFID in *** proposed study has superior performance and effective results.

关键词： RFID healthcare information technology user factors

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A Positron Study of Hysteresis Temperature in Ti-Ni Alloy

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Journal of Materials Science & Technology 1996年第6期12卷 470-472页

作者： Wang, JC Qin, GY Zhang, GL Zheng, wh Chen, LY Gu, M ACAD SINICA SHANGHAI INST NUCL RESSHANGHAI 201800PEOPLES R CHINA TONGJI UNIV DEPT PHYSSHANGHAI 200092PEOPLES R CHINA

For Ti-Ni alloy, it is exceedingly difficult; to prepare an element that has a desired and defined hysteresis temperature for its preparing process is not perfect at present. Because the mechanism of transformation in Ti-Ni has not been fully clarified, it is far more exceedingly difficult to explain the hysteresis temperature only by using the traditional metal physics techniques. But position annihilation seems to be a suitable method for it. The positron annihilation measurements show that the hysteresis temperature may be controlled mainly by the relative fraction of the defects contained in a two-way shape memory element.

关键词： Titanium alloys

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