检索结果-南通市图书馆

Digital monitoring of rotary-percussive drilling with down-the-hole hammer for profiling weathered granitic ground

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1615-1636页

作者： Wendal victor Yue Siyuan Wu Manchao He Yafei Qiao Zhongqi quentin Yue Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai200092China Department of Civil Engineering Faculty of EngineeringThe University of Hong KongPokfulam RoadHong KongChina State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing100083China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai200092China

Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground *** the basis of an actual soil nailing drilling for a slope stability project in Hong Kong,this paper further develops the drilling process monitoring(DPM)method for digitally profiling the subsurface geomaterials of weathered granitic rocks using a compressed airflow driven percussive-rotary drilling machine with down-the-hole(DTH)*** transducers are installed on the drilling machine and record the chuck displacement,DTH rotational speed,and five pressures from five compressed airflows in real-time *** mechanism and operations of the drilling machine are elaborated in detail,which is essential for understanding and evaluating the drilling data.A MATLAB program is developed to automatically filter the recorded drilling data in time series and classify them into different drilling processes in sub-time *** processes include penetration,push-in with or without rod,pull-back with or without rod,rod-tightening and *** drilling data are further reconstructed to plot the curve of drill-bit depth versus the net drilling time along each of the six *** curve is found to contain multiple linear segments with a constant penetration rate,which implies a zone of homogenous geomaterial with different weathering *** effect from fluctuation of the applied pressures is evaluated *** analyses are presented for accurately assess and verify the underground profiling and strength in weathered granitic rock,which provided the basis of using DPM method to confidently assess drilling measurements to interpret the subsurface profile in real time.

关键词： Drilling process monitoring(DPM) Down-the-hole(DTH)hammer Percussive-rotary drilling Weathering granitic rocks

Reliability Study of a New Electromechanical Device Designed to Measure the Relative Dorsal Mobility of the First Ray of the Foot

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Orthopedics 2022年第10期12卷 383-392页

作者： Nils Reymond quentin Praz Spyridon Schoinas Navindravadhanam Sockalingam Antoine Acker victor Dubois-Ferrière Philippe Passeraub Mathieu Assal Centre Assal for Foot and Ankle Surgery Clinique La Colline Geneva Switzerland Institute of Industrial Technologies and Sciences University of Applied Sciences and Arts Western Switzerland (HES-SO Geneva/HEPIA) Geneva Switzerland

Introduction: A new electromechanical instrument has been developed to measure relative dorsal mobility of the first ray in an objective and reliable way by simulating ground reaction forces during gait. This device equally applies a standardized, electronically controlled, and precise force under the first metatarsal head M1 as well as under the heads of the lesser metatarsals M2 to M5. The relative dorsal mobility between these two bearings is then measured. The purpose of this study is to assess the intra- and inter-examiners reliabilities of the measurements obtained with this device. Methods: The protocol included two examiners and 36 feet (18 volunteers with healthy feet and no history of forefoot disorders). A total of nine measurements were performed on each foot separated into three sets of three trials for the assessment of inter-rater and intra-rater reliability. For this purpose, the interclass correlation coefficient (ICC), the error of measurement (SEM) and the Bland and Altman (B&A) graphical analysis were computed. Results: Excellent ICC values (≥0.91) were obtained with the novel device for inter-rater and intra-rater reliability when using the FRRM calculation. The B&A analysis presented a bias between examiners of -0.25 mm ranging from -1.66 to 1.18 mm. Conclusion: This study demonstrated the capability of the developed device to reliably measure the relative dorsal mobility of the first ray of the foot. This is a promising first step for further studies to better understand, qualify and quantify first ray hypermobility.

关键词： First Ray Dorsal Mobility Instability Hypermobility Medical Device Reliability Study Foot

Preoperative rectosigmoid endoscopic ultrasonography predicts the need for bowel resection in endometriosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2019年第6期25卷 696-706页

作者： victor Desplats René-Louis Vitte Joseph du Cheyron Gilles Roseau Arnaud Fauconnier Frédérick Moryoussef Department of Hepato-gastroenterology Centre Hospitalier Intercommunal Poissy Saint Germain Department of Statistics Centre Hospitalier Intercommunal Poissy Saint Germain Department of Gastroenterology H?pital Cochin Department of Obstetrics and Gynecology Centre Hospitalier Intercommunal Poissy Saint Germain University of Saint Quentin en Yvelines

BACKGROUND Rectosigmoid endometriosis is an underdiagnosed disease responsible for abdominal pain, transit disorders and rectal bleeding. Two surgical approaches,rectosigmoid bowel resection(segmental or patch) or intramuscular layer dissection(shaving), are *** To assess whether the lesion features observed via preoperative rectosigmoid endoscopic ultrasonography(RS-EUS) might predict the need for bowel *** This multicentric retrospective study was conducted on patients with rectosigmoid endometriosis who underwent a curative surgical procedure,evaluated by RS-EUS performed by two trained operators, between January 2012 and March 2018. A univariate statistical analysis was performed on nodules' RSEUS features(thickness, width, infiltration of the submucosae, presence of a bump into the digestive lumen and presence of multiple rectosigmoid localizations). A multivariate logistic regression was then performed on the significant *** Of the 367 patients, 73 patients with rectosigmoid endometriosis were evaluated by RS-EUS and underwent rectosigmoid surgery. After the univariate analysis was completed, thickness, width and infiltration of the submucosae were identified as potential predictive factors for bowel resection. In a multivariate logistic regression model, only thickness appeared to be a significant [odds ratio(OR) = 1.49, 95% confidence interval(CI): 1.04-2.12, P = 0.028] predictive factor for bowel resection. Receiver operating characteristic analysis performed showed that a thickness over 5.20 mm might be used as cut-off with a sensitivity of 76%, a specificity of 81%, and an area under carve = 0.82. The cut-off values for 100%sensitivity and 100% specificity were 0.90 mm and 10.00 mm, respectively. A trend concerning width to predict the need for resection was also observed(OR1.12, 95%CI: 1.00-1.26, P = 0.054)CONCLUSION The presence of a rectosigmoid nodule of endometriosis greater than 5.20 mm thick on RS-EUS might predi

关键词： Endometriosis Surgery Endoscopy Ultrasound Bowel disease Rectum and sigmoid

Huge metastable axial strain in ultrathin heteroepitaxial vertically aligned nanowires

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第6期8卷 1964-1974页

作者： Vivien Schuler Francisco Javier Bonilia Dominique Demaille Alessandro Coati Alina Vlad Yves Garreau Michele Sauvage-Simkin Anastasiia Novikova Emiliano Fonda Sarah Hidki victor Etgens Franck Vidal Yunlin Zheng Sorbonne Universites UPMC Institut des NonoSciences de Paris 4 place Jussieu Paris 75005 France CNRS UMR7588 Institut des NanoSciences de Paris 4 place Jussieu Paris 75005 France Synchrotron Soleil L'Orme des Merisiers Saint-Aubin BP 48 91192 Gif-sur-Yvette Cedex France Universite Paris Diderot Sorbonne Paris Cite MPO UMR 7162 CNRS Batiment Condorcet Case courrier 7021 75205 Paris Cedex 13 France Universite de Versailles Saint-quentin en Yvelines 55 Av. de Paris Versailles 78035 France

Strain engineering is a powerful tool to tailor the physical properties of materials coherently stacked in an epitaxial heterostructure. Such an approach, applied to the mature field of planar heteroepitaxy, has yielded a variety of new phenomena and devices. Recently, heteroepitaxial vertically aligned nanocomposites have emerged as alternatives to planar structures. Owing to the peculiar geometry of such nanoarchitectures, efficient strain control can be achieved, opening the way to novel functionalities. In this paper, we report a very large tensile axial strain in epitaxial transition metal nanowires embedded in an oxide matrix. We show that axial strains in excess of 1.5% can be sustained over a large thickness （a few hundred nanometers） in epitaxial nanowires having ultrasmall diameters （-3-6 nm）. The axial strain depends on the diameter of the nanowires, reflecting its epitaxial nature and the balance of interface and elastic energies. Furthermore, it is experimentally shown that such strain is metastable, in agreement with the calculations performed in the framework of the Frenkel-Kontorova model. The diameter dependence and metastability provide effective ways to control the strain, an appealing feature for the design of functional nanoarchitectures.

关键词： self-assembly heteroepitaxy nanowires strain

A novel Hainan ConotoxinPotently Blocks a9alO Nicotinic Acetylcholine Receptors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A novel Hainan ConotoxinPotently Blocks a9alO Nicotinic Acet...