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Colonic perforation by a transmural and transvalvular migrated Retained sponge:Multi-detector computed tomography findings

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World Journal of Gastroenterology 2014年第15期20卷 4457-4461页

作者： Luigi Camera Marco Sagnelli Paolo Guadagno Pier Paolo Mainenti Teresa Marra Maria Scotto di Santolo Landino Fei Marco Salvatore Department of Radiology University "Federico Ⅱ"80131 NaplesItaly Institute of Biostructures and Bioimaging National Research Council (CNR)-Via Tommaso De Amicis 9580131 NaplesItaly Gastrointestinal Surgery Unit-Second University School 80131 NaplesItaly

Transmural migrated Retained sponges usually impact at the level of the ileo-cecal valve leading to a small bowel obstruction.Once passed through the ileo-cecal valve,a Retained sponge can be propelled forward by peristaltic activity and eliminated with feces.We report the case of a 52-year-old female with a past surgical history and recurrent episodes of abdominal pain and constipation.On physical examination,a generalized resistance was observed with tenderness in the right flank.Contrast-enhanced multi-detector computed tomography findings were consistent with a perforated right colonic diverticulitis with several out-pouchings at the level of the ascending colon and evidence of free air in the right parieto-colic gutter along with an air-fluid collection within the mesentery.In addition,a ring-shaped hyperdense intraluminal material was also noted.At surgery,the ascending colon appeared irregularly thickened and folded with a focal wall interruption and a peri-visceral abscess at the level of the hepatic flexure,but no diverticula were found.A right hemi-colectomy was performed and on dissection of the surgical specimen a Retained laparotomy sponge was found in the bowel lumen.

关键词： Retained sponge Transmural migration Multi-detecto

Wide pillar roadway Retained in the deep high gas coal seam

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International Journal of Mining Science and Technology 2012年第6期22卷 828-831页

作者： Pan Liyou Feng Enhu Zhao Qingshou Chen Liqiang Kong Fanpeng Institute of Mining Engineering Shandong University of Science and Technology Bao'an Mine Shanxi Coal Transportation and Sales Group Co.Ltd. College of Natural Resources and Environmental Engineering Shandong University of Science and Technology

According to the geological and mining conditions of deep high gas coal seam,this paper established the mechanical model of stope surrounding rock,and analyzed the stress distribution and deformation failure mechanism of working face and coal pillar.The research determined the arrangement mode that adjacent working faces retain wide pillar,and the reasonable support method of roadway that the combined support of roof and grouting combined together.The reasonable time of reinforced roadway was determined.Through analyzing the mechanical model of the ways of roadway supporting,this research drew the conclusions as follows:the combined support of roof and working slope improved the support strength and range of surrounding rock,optimized the support by adjusting the angle of anchor,and reached the support requirements by using cement grouting in working slope and chemical grout in roof.The technology was applied in 15104 working face of Baoan Mine,and obtained good results.

关键词： Gas Roadway Retained Wide pillar Stress distribution Combined support of roof and working slope Grouting

Effect of Microstructure on Tensile Behavior and Mechanical Stability of Retained Austenite in a Cold-Rolled Al-Containing TRIP Steel

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Acta Metallurgica Sinica(English Letters) 2019年第10期32卷 1237-1243页

作者： Yang Zhao Wen-Ting Zhu Shu Yan Li-Qing Chen School of Materials Science and Engineering Northeastern University Shenyang 110819 China State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 China

In the present study, a quenching treatment prior to two-stage heat treatment was conducted on a Fe-0.28C-1.55Mn-2.06Al transformation-induced plasticity steel to tailor the final microstructure. Compared with the microstructure of the ferrite, bainite and blocky Retained austenite obtained by conventional two-stage heat treatment, the microstructure subjected to quenching plus two-stage heat treatment was composed of the ferrite, lath bainite and film-like Retained austenite. The corresponding tensile behavior and mechanical stability of Retained austenite were investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results show that the mechanical stability of blocky Retained austenite grains is lower and most of them transform to martensite during the tensile deformation, which leads to higher ultimate tensile strength and instantaneous work hardening exponent. Film-like Retained austenite has relatively higher stability, which could cause sustained work hardening and high ductility as well as product of strength and elongation.

关键词： Transformation-induced plasticity (TRIP) steel Retained austenite stability Microstructure Mechanical properties Work hardening behavior

Mechanical Properties and Retained Austenite Stability of High Aluminum TRIP-aided Cold-rolled Steel Sheets

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稀有金属材料与工程 2011年第S3期40卷 1-4页

作者： Kim Sungjoon Korea Institute of Machinery and Materials

The mechanical properties, microstructure and Retained austenite stability of CMnAlSi-TRIP steels were investigated in this paper. The steel sheets were hot-rolled, cold-rolled and heat treated by intercritical annealing and isothermal heat treatment. The microstructure, volume fraction of Retained austenite and its carbon concentration were observed by Optical microscopy and X-ray diffraction. The mechanical properties were obtained through uniaxial tensile test. The results show that the CMnAlSi cold-rolled TRIP-aided steels have good combination of strength and ductility with proper isothermal heat treatment, the Retained austenite stability determines incremental strain hardening exponent during strain-induced martensitic transformation, and affected by its volume fraction and carbon content. The Retained austenite stability has a good correlation with the combination of strength and ductility.

关键词： TRIP carbon content mechanical properties Retained austenite stability

Effect of Retained austenite and nonmetallic inclusions on the thermal/electrical properties and resistance spot welding nuggets of Si-containing TRIP steels

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International Journal of Minerals,Metallurgy and Materials 2019年第1期26卷 52-63页

作者： V.H.Vargas I.Mejía V.H.Baltazar-Hernández C.Maldonado Metallurgy and Materials Research Institute Universidad Michoacana de San Nicolás de Hidalgo Edificio "U" Ciudad Universitaria Materials Science and Engineering Program Autonomous University of Zacatecas

Five advanced high-strength transformation-induced plasticity(TRIP) steels with different chemical compositions were studied to correlate the Retained austenite and nonmetallic inclusion content with their physical properties and the characteristics of the resistance spot welding nuggets. Electrical and thermal properties and equilibrium phases of TRIP steels were predicted using the JMatPro? software. Retained austenite and nonmetallic inclusions were quantified by X-ray diffraction and saturation magnetization techniques. The nonmetallic inclusions were characterized by scanning electron microscopy. The results show that the contents of Si, C, Al, and Mn in TRIP steels increase both the Retained austenite and the nonmetallic inclusion contents. We found that nonmetallic inclusions affect the thermal and electrical properties of the TRIP steels and that the differences between these properties tend to result in different cooling rates during the welding process. The results are discussed in terms of the electrical and thermal properties determined from the chemical composition and their impact on the resistance spot welding nuggets.

关键词： transformation-induced plasticity steel Retained austenite non-metallic inclusions magnetic saturation electrical properties thermal properties resistance spot welding nugget

Effect of Prior Cold Deformation on the Stability of Retained Austenite in GCr15 Bearing Steel

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Acta Metallurgica Sinica(English Letters) 2019年第1期32卷 107-115页

作者： Feng Wang Dong-Sheng Qian Xiao-Hui Lu School of Materials Science and Engineering Wuhan University of Technology Hubei Key Laboratory of Advanced Technology for Automotive Components School of Automotive Engineering Wuhan University of Technology

In this work, the effect of prior cold deformation on the stability of Retained austenite in GCr15 bearing steel was investigated after quenching and tempering treatment. The thermal stability was evaluated by calculating thermal activation energy for decomposition of Retained austenite using differential scanning calorimeter. The mechanical stability was investigated according to the strain-induced martensitic transformation behavior of Retained austenite under the standard compression testing. It is found that the prior cold deformation not only accelerates the carbide dissolution during the austenitization process but also contributes to the carbon partitioning in the tempering stage due to the higher density of phase boundaries, which results in the improvement of the thermal stability of Retained austenite. Due to the enhanced carbide dissolution, the higher carbon content in the prior austenite will intensify the isotropic strain of martensitic transformation. As a consequence, the film-like Retained austenite is likely to form under a higher hydrostatic pressure and thus shows a higher mechanical stability. Additionally, it is noteworthy that the benefits of the prior cold deformation to the stability of Retained austenite would be saturated when the cold deformation degree is larger than 40%.

关键词： GCr15 bearing steel Prior cold deformation Retained austenite stability

Transmural penetration of sigmoid colon and rectum by Retained surgical sponge after hysterectomy

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World Journal of Gastroenterology 2016年第10期22卷 3052-3055页

作者： Woo Young Shin Chan Hyuk Im Sun Keun Choi Yun-Mee Choe Kyung Rae Kim Department of Surgery Inha University HospitalInha University College of Medicine

Gossypiboma is a surgical sponge that is Retained in the body after the operation. A 39-year-old female presented with vague lower abdominal pain, fever, and rectal discharge 15 mo after hysterectomy. The sponge remaining in the abdomen had no radiopaque marker. Therefore a series of radiographic evaluations was fruitless. The surgical sponge was found in the rectosigmoid colon on colonoscopy. The sponge penetrated the sigmoid colon and rectum transmurally, forming an opening on both sides. The patient underwent low anterior resection and was discharged without postoperative complications.

关键词： Gossypiboma Textiloma Retained foreign object Surgical sponge Radiopaque marker

Physical Simulation of Thermally Induced Martensite Formation from Retained Austenite in TRIP Steels

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Journal of Materials Science & Technology 2003年第z1期19卷 105-108页

作者： Lie ZHAO Fred J. VERMOLEN Jilt SIETSMA Sybrand van der ZWAAG Netherlands Institute for Metals Research P.O.Box 5008 2600 GA Delft The Netherlands Department of Materials Science Delft University of Technology R otterdamseweg 137 2628 AL Delft The Netherlands Department of Applied Mathematics Delft University of Technology Mekelweg 4 2628 CD Delft The Netherlands Department of Materials ScienceDelft University of TechnologyRotterdamseweg 1372628 AL DelftThe Netherlands Netherlands Institute for Metals Research P.O.Box 5008 2600 GA Delft The Netherlands Faculty of Aerospace Engineering Delft University of Technology Kluyverweg 1 2629 HS Delft The Netherlands

The present work analyses the total free energy of the material during the martensitic transformation. A general expression for the martensite fraction as a function of temperature is derived, assuming that the nonchemical free energyis proportional to the volume of martensite. This expression indicates that the temperature-dependent martensitefraction can be predicted once the characteristic transformation temperatures and the relation between the chemicalfree energy and temperature of the martensite and austenite are known. An advantage of this development is thatthe proposed equation is valid for all types of relations between the chemical free energy and temperature. Thissimulation is successfully applied to the martensitic transformation upon further cooling of Retained austenite in alow-alloyed TRIP steel, in which the relation between chemical free energy and temperature is quadratic and thefraction is determined from a thermo-magnetic measurement.

关键词： Thermodynamics, Martensitic transformation, Retained austenite, TRIP steels.

Topical nitrate drip infusion using cystic duct tube for Retained bile duct stone:A six patients case series

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World Journal of Gastrointestinal Surgery 2013年第6期5卷 210-215页

作者： Masatoshi Shoji Hiroshi Sakuma Yutaka Yoshimitsu Tsutomu Maeda Masuo Nakai Hiroshi Ueda Department of Surgery Hoju Memorial HospitalNomiIshikawa 923-1226Japan

A Retained bile duct stone after operation for cholelithiasis still occurs and causes symptoms such as biliary colic and obstructive jaundice.An endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy(EST),followed by stone extraction,are usually an effective treatment for this condition.However,these procedures are associated with severe complications including pancreatitis,bleeding,and duodenal perforation.Nitrates such as glyceryl trinitrate(GTN) and isosorbide dinitrate(ISDN) are known to relax the sphincter of Oddi.In 6 cases in which a Retained stone was detected following cholecystectomy,topical nitrate drip infusion via cystic duct tube(C-tube) was carried out.Retained stones of 2-3 mm diameter and no dilated common bile duct in 3 patients were removed by drip infusion of 50 mg GTN or 10 mg ISDN,which was the regular dose of intravenous injection.Three other cases failed,and EST in 2 cases and endoscopic biliary balloon dilatation in 1 case were performed.One patient developed an adverse event of nausea.Severe complications were not observed.We consider the topical nitrate drip infusion via C-tube to be old but safe,easy,and inexpensive procedure for Retained bile duct stone following cholecystectomy,inasmuch as removal rate was about 50% in our cases.

关键词： Nitrate Topical drip infusion Cystic duct tube Retained bile duct stone Cholecystectomy