检索结果-南通市图书馆

Comparative prospective study between medial and lateral distal tibial locking compression plates for distal third tibial fractures

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Traumatology 2017年第3期20卷 151-154页

作者： Sandeep Garg Vikram Khanna Mahaveer Prashad Goyal narendra joshi Amrut Borade Ishan Ghuse Department of Orthopaedics Sawai Mansingh Medical College & Affiliated Hospital Jaipur India Department of Orthopaedics National Institute of Medical Sdences Jaipur India

Purpose： Tibial fracture is the most common long bone fracture. Distal third tibial fractures are chal- lenging though open reduction and plating can result in anatomical reduction and rigid fixation. This paper aimed to evaluate and compare the results of medial and lateral locking compression plates for distal third tibial fractures. Methods： This prospective clinical study involved 36 patients with distal tibial fractures admitted in Department of Orthopaedics, Sawai Mansingh Medical College ＆ Affiliated Hospital, Jaipur, India, from June 2011 to May 2012, including 29 closed fractures and 7 open fractures at the mean age of 38.9 years. Thirty-six patients were divided equally into two groups based on treatment method, including medial plating group （18 patients） and lateral plating group （18 patients）. They were followed up for at least 5 months after discharge. The functional outcomes were evaluated using Tenny and Wiss clinical assess- ment criteria. Results： Malunion was found in 3 cases of medial plating group and in 1 case of lateral plating group. In the medial plating group, there were 5 cases of superficial infections, 1 deep infection, 1 nonunion and 3 wound dehiscence. In the lateral plating group, there was 1 case of superficial infections, 1 deep infection and 1 nonunion, in the lateral plating group, 4 patients reported feeling the plates and screws but none of them asked to remove the hardware. In the medial plating group, 9 patients reported symptomatic hardware problems and 7 asked to remove the hardware. The number of cases graded as excellent/good/ fair was 1/8/7 in the medial plating group and 3/7/7 in the lateral plating group respectively. In the medial plating group, the final range of motion was 17.2° in ankle dorsiflexion and 30.7° in ankle plantar flexion. In the lateral plating group, the final range of motion was 19° in ankle dorsiflexion and 34.2° in ankle plantar flexion. Conclusion： Lateral plating of distal tibia is safe and feasib

关键词： Tibial fractures Bone plates Open fracture reduction

Cu–Co–O nano-catalysts as a burn rate modifier for composite solid propellants

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2016年第4期12卷 297-304页

作者： D. Chaitanya Kumar RAO narendra YADAV Puran Chandra joshi Space Engineering and Rocketry Birla Institute of Technology Mesra Ranchi 835215 India

Nano-catalysts containing copper–cobalt oxides(Cu–Co–O) have been synthesized by the citric acid(CA) complexing method. Copper(II) nitrate and Cobalt(II) nitrate were employed in different molar ratios as the starting reactants to prepare three types of nano-catalysts. Well crystalline nano-catalysts were produced after a period of 3 hours by the calcination of CA–Cu–Co–O precursors at 550 °C. The phase morphologies and crystal composition of synthesized nano-catalysts were examined using Scanning Electron Microscope(SEM), Energy Dispersive Spectroscopy(EDS) and Fourier Transform Infrared Spectroscopy(FTIR) methods. The particle size of nano-catalysts was observed in the range of 90 nm–200 nm. The prepared nano-catalysts were used to formulate propellant samples of various compositions which showed high reactivity toward the combustion of HTPB/AP-based composite solid propellants. The catalytic effects on the decomposition of propellant samples were found to be significant at higher temperatures. The combustion characteristics of composite solid propellants were significantly improved by the incorporation of nano-catalysts. Out of the three catalysts studied in the present work, Cu Co-I was found to be the better catalyst in regard to thermal decomposition and burning nature of composite solid propellants. The improved performance of composite solid propellant can be attributed to the high crystallinity, low agglomeration and lowering the decomposition temperature of oxidizer by the addition of Cu Co-I nano-catalyst.

关键词： Metal oxides Nano-catalysts Solid propellant Burn rate Surface morphology Thermal analysis

Additive friction stir deposition of AZ31B magnesium alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第9期10卷 2404-2420页

作者： Sameehan S.joshi Shreyash M.Patil Sangram Mazumder Shashank Sharma Daniel A.Riley Shelden Dowden Rajarshi Banerjee narendra B.Dahotre Department of Materials Science and Engineering University of North Texas3940 N Elm StDentonTX 76207USA Center for Agile and Adaptive Additive Manufacturing University of North Texas3940 N Elm StDentonTX 76207USA

The current work explored additive friction stir deposition of AZ31B magnesium alloy with the aid of MELD?***31B magnesium bar stock was fed through a hollow friction stir tool rotating at constant velocity of 400 rpm and translating at linear velocity varied from 4.2 to 6.3 mm/s.A single wall consisting of five layers with each layer of 140×40×1 mm^(3)dimensions was deposited under each processing ***,phase,and crystallographic texture evolutions as a function of additive friction stir deposition parameters were studied with the aid of scanning electron microscopy including electron back scatter diffraction and X-ray *** feed material and additively produced samples consisted of theα-Mg *** additively produced samples exhibited a refined grain structure compared to the feed *** feed material appeared to have a weak basal texture,while the additively produced samples experienced a strengthening of this basal *** additively produced samples showed a marginally higher hardness compared to the feed *** current work provided a pathway for solid state additive manufacturing of Mg suitable for structural applications such as automotive components and consumable biomedical implants.

关键词： Additive friction stir deposition Magnesium alloys Additive manufacturing Thermomechanical processing Materials processing Solid state additive manufacturing

Microstructure and surface texture driven improvement in in-vitro response of laser surface processed AZ31B magnesium alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2021年第4期9卷 1414-1426页

作者： Tso-Chang Wu Sameehan Sjoshi Yee-Hsien Ho Mangesh VPantawane Subhasis Sinha narendra B.Dahotre Department of Materials Science and Engineering University of North Texas3940 N Elm StDentonTX 76207USA Center for Agile and Adaptive Additive Manufacturing University of North Texas3940 N Elm StDentonTX 76207USA Department of Metallurgical Engineering Indian Institute of Technology(BHU)VaranasiUttar Pradesh 221005India

The present work explored effects of laser surface melting on microstructure and surface topography evolution in AZ31B magnesium *** effects experienced by the material during laser surface melting were simulated using a multiphysics finite element *** and phase evolution were examined using scanning electron microscopy,X-ray diffraction,and electron back scatter *** topography was evaluated using white light *** interaction of surface melted samples with simulated body fluid was monitored by contact angle measurements and immersion studies up to 7 *** surface melting led to formation of a refined microstructure with predominantly basal crystallographic ***,the amount ofβphase(Mg_(17)Al_(12))increased with an increase in the laser fluence.βphase preferentially decorated the cell *** terms of topography,the surface became progressively rougher with an increase in laser *** a result,upon immersion in simulated body fluid,the laser surface melted samples showed an improved wettability,corrosion resistance,and precipitation of mineral having composition closer to the hydroxyapatite bone mineral compared to the untreated sample.

关键词： Laser surface melting Magnesium alloy Laser surface engineering Biomineralization

In-vitro biomineralization and biocompatibility of friction stir additively manufactured AZ31B magnesium alloy-hydroxyapatite composites

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2020年第4期5卷 891-901页

作者： Yee-Hsien Ho Kun Man Sameehan S.joshi Mangesh V.Pantawane Tso-Chang Wu Yong Yang narendra B.Dahotre Laboratory for Laser Aided Additive and Subtractive Manufacturing Department of Materials Science and EngineeringUniversity of North Texas1150 Union Circle 305310DentonTX76203-5017USA Department of Biomedical Engineering University of North Texas1150 Union Circle 305310DentonTX76203-5017USA

The present study aims to evaluate effect of hydroxyapatite(HA,Ca10(PO4)6OH2),a ceramic similar to natural bone,into AZ31B Mg alloy matrix on biomineralization and *** novel friction stir processing additive manufacturing route was employed to fabricate Mg-HA *** HA contents(5,10,20 wt%)were incorporated into Mg *** observation and chemical composition analysis revealed that refined Mg grains and dispersion of HA particles at micro/nanoscales were achieved in Mg-HA composites after the friction stir *** biomineralization evaluation were carried out using immersion experiments in simulated body fluid followed by mineral morphology observation and chemical composition *** wettability measurements were conducted to correlate the biomineralization *** results showed improvement in wettability and bone-like Ca/P ratio in apatite deposit on the composites compared to as-received *** addition,the increase of blood compatibility,cell viability and spreading were found in the higher HA content composites,indicating the improved ***,friction stir processed Mg-20 wt%HA composite exhibited the highest wettability and better cell adhesion among other composites due to the effect of increased HA content within Mg matrix.

关键词： Friction stir processing Magnesium alloy Hydroxyapatite Additive manufacturing Biomineralization Contact angle measurement Blood compatibility Cell culture