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Effect of TiN Particles and Grain Size on the Charpy Impact Transition Temperature in Steels

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journal of Materials Science & Technology 2012年第10期28卷 878-888页

作者： j.Du M.Strangwood C.L.davis School of Metallurgy and Materials University of Birmingham

The toughness of ferritic steels is influenced by the grain size distribution, second phase, precipitates and coarse inclusions. In this work an examination of the effect of coarse TiN particles （〉0.5 μm） and ferrite grain size on the Charpy impact transition temperature in high strength low alloyed steels has been carried out. Steels with high Ti content （up to 0.045 wt%）, have been heat-treated and furnace cooled to obtain a ferrite-pearlite microstructure with different ferrite grain sizes. Coarse TiN particle size and ferrite grain size distributions have been measured and Charpy impact testing has been carried out. Scanning electron microscopy （SEM） analysis has been used to measure the grain boundary carbide thickness and to determine if the coarse TiN particles are acting as cleavage initiation sites by fractographic analysis. The Charpy ductile-brittle transition temperatures （DBTT） have been predicted using standard literature equations, and compared to the measured values. The relationship between the ferrite grain size and coarse TiN particle size and number density in terms of whether the coarse TiN particles act as effective cleavage initiation sites is discussed in this paper.

关键词： TiN particles Grain size Charpy impact test Ductile-brittle transitiontemperatures (DBTT) Steels

Prostate cancer upgrading or downgrading of biopsy Gleason scores at radical prostatectomy:prediction of"regression to the mean"using routine clinical features with correlating biochemical relapse rates

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Asian journal of Andrology 2019年第6期21卷 598-604页

作者： Muammer Altok Patricia Troncoso Mary f Achim Surena f Matin Graciela N Gonzalez john W davis Department of Urology University of Texas MD Anderson Cancer CenterHoustonTX 77030USA Department of Pathology University of Texas MD Anderson Cancer CenterHoustonTX 77030USA Department of Biostatistics University of Texas MD Anderson Cancer CenterHoustonTX 77030USA.

Recommendations for managing clinically localized prostate cancer are structured around clinical risk criteria,with prostate biopsy(PB)Gleason score(GS)being the most important *** to radical prostatectomy(RP)specimen upgrading/downgrading is welldescribed,and is often the ratio nale for costly imaging or genomic *** prese nt simple,no-cost an a lyses of clinical parametersto predict which GS 6 and GS 8 patients will change to GS 7 at *** May 2006 to December 2012,1590 patientsunderwent robot-assisted radical prostatectomy(RARP).After exclusions,we identified a GS 6 cohort of 374 patients and a GS 8cohort of 91 *** this era,>1000 additional patients were enrolled in an active surveillanee(AS)*** GS 6,265(70.9%)of 374 patients were upgraded,and the cohort included 183(48.9%)patients eligible for AS by the Prostate Cancer ResearchInternational Active Surveillance Study(PRIAS)standards,of which 57.9%were *** features that predicted a>90%chanceof upgrading included≥7 cores positive,maximum foci length≥8 mm in any core,and total tumor involvement≥30%.for GS 8,downgrading occurred in 46(50.5%),which was significantly higher for single core versus multiple cores(80.4%vs 19.6%,P=0.011).Biochemical recurre nee(BCR)occurred in 3.4%of GS 6 upgraded versus 0%non upgraded,and in GS 8,19.6%downgraded versus42.2%nondown *** coun seling men with clin ically localized prostate can cer,the odds of GS cha nge should be presented,andcertain men with high-volume GS 6 or low-volume GS 8 can be counseled with GS 7-based recommendations.

关键词： biopsy down grade Gleas on score prostate cancer upgrade

Growth and differentiation of human induced pluripotent stem cell(hiPSC)-derived kidney organoids using fully synthetic peptide hydrogels

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Bioactive Materials 2023年第3期21卷 142-156页

作者： Niall j.Treacy Shane Clerkin jessica L.davis Ciar´an Kennedy Aline f.Miller Alberto Saiani jacek K.Wychowaniec Dermot f.Brougham john Crean Diabetes Complications Research Centre University College Dublin(UCD)Conway Institute of Biomolecular and Biomedical Research and BelfieldDublin 4Ireland UCD School of Biomolecular and Biomedical Science BelfieldDublin 4Ireland Department of Materials&Manchester Institute of Biotechnology(MIB) School of Natural SciencesFaculty of Science and EngineeringThe University of ManchesterUK UCD School of Chemistry University College DublinBelfieldDublin 4Ireland

Human induced pluripotent stem cell(hiPSC)-derived kidney organoids have prospective applications ranging from basic disease modelling to personalised ***,there remains a necessity to refine the bio-physical and biochemical parameters that govern kidney organoid *** within fully-controllable and physiologically relevant 3D growth environments will be critical to improving organoid reproducibility and ***,we matured hiPSC-derived kidney organoids within fully synthetic self-assembling peptide hydrogels(SAPHs)of variable stiffness(storage modulus,G′).The resulting organoids con-tained complex structures comparable to those differentiated within the animal-derived matrix,***-cell RNA sequencing(scRNA-seq)was then used to compare organoids matured within SAPHs to those grown within Matrigel or at the air-liquid interface.A total of 13,179 cells were analysed,revealing 14 distinct *** compositional analysis revealed a larger proportion of nephron cell types within Transwell-derived organoids,while SAPH-derived organoids were enriched for stromal-associated cell ***,dif-ferentiation within a higher G’SAPH generated podocytes with more mature gene expression ***-tionally,maturation within a 3D microenvironment significantly reduced the derivation of off-target cell types,which are a known limitation of current kidney organoid *** work demonstrates the utility of syn-thetic peptide-based hydrogels with a defined stiffness,as a minimally complex microenvironment for the selected differentiation of kidney organoids.

关键词： Human kidney organoids fully synthetic matrices Self-assembling peptide hydrogels Single-cell RNA sequencing

Investigation on the influence of the initial RDX crystal size on the performance of shaped charge warheads

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Defence Technology（防务技术） 2019年第5期15卷 802-807页

作者： f.Majiet f.j.Mostert Rheinmetall Denel Munition Somerset WestSouth Africa Centre for Scientific&Industrial Research PretoriaSouth Africa

Copper lined wave shaped shaped charges of particular design and liner metallurgy were used to investigate the effect of explosive crystal size on the resultant shaped charge jet *** A3 with RDX of three different average crystal sizes,i.e.30μm,100μm and 300μm were used in the *** other parameters in the charge were kept constant and in particular,care was given to obtain consistent dimensional quality and liner microstructure,in order to prohibit the variation of other *** flash-X-ray diagnostics were used in field tests to obtain the jet parameters from multiple firings of similar *** is found that the varying crystal size of the RDX has a marginal influence in the total jet length of the ***,it is also found that there is less variation between firings in the jet parameters for jets from the charges loaded with the crystal size of 100 μm.

关键词： shaped size crystal

Discrete composition control of two-dimensional morphologic all-inorganic metal halide perovskite nanocrystals

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journal of Energy Chemistry 2021年第8期30卷 257-275,I0006页

作者： Andrew Hunter davis Weiwei Zheng Department of Chemistry Syracuse University13244 SyracuseUnited States

Metal halide perovskite nanocrystals(NCs)exhibit impressive optical and electronic properties,making them an important class of functional materials with promising applications in solar cells,light emitting diodes(LEDs),photodetectors,and *** addition to the widely studied 0-dimensional(0 D)metal halide perovskite NCs,such as nanocubes,low dimensional perovskites,such as 2 D all-inorganic perovskite(AIP)NCs,subsist with directionally relevant quantum *** anisotropic NCs have the propensity to exhibit interesting optoelectronic properties that are exceedingly difficult to introduce into 0 D systems,yet as of late are largely *** this review,we discuss the recent synthetic progress of 2 D all-inorganic metal halide perovskite NCs with ABX3 ***,we highlight the discrete composition control of the cations(A and B sites)and anions(X site)by dopant incorporation and alloying in 2 D metal halide perovskite *** will also discuss more complex perovskite crystal structures,such as Ruddlesden-Popper double perovskites,and compare these materials to 0 D perovskite ***,our work culminates in the future interests and perspectives of this field with a focus on the wide applicability of 2 D systems and the large variance in structure capable with discrete compositional tuning.

关键词： All-inorganic perovskites Two-dimensional nanocrystals Composition Doping Alloying Ion exchange

Implementation of a Roughness Element to Trip Transition in Large-eddy Simulation

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journal of Thermal Science 2015年第1期24卷 30-36页

作者： j.Boudet j.-f.Monier f.Gao LMfA Ecole Centrale de Lyon Université de Lyon–UMR CNRS 5509 69134 Ecully Cedex France PhD.Candidate Université de Lyon–UMR CNRS 5509 69134 Ecully Cedex France

In aerodynamics, the laminar or turbulent regime of a boundary layer has a strong influence on friction or heat transfer. In practical applications, it is sometimes necessary to trip the transition to turbulent, and a common way is by use of a roughness element （e.g. a step） on the wall. The present paper is concerned with the numerical im- plementation of such a trip in large-eddy simulations. The study is carried out on a flat-plate boundary layer con- figuration, with Reynolds number Rex=l.3x 106. first, this work brings the opportunity to introduce a practical methodology to assess convergence in large-eddy simulations. Second, concerning the trip implementation, a volume source term is proposed and is shown to yield a smoother and faster transition than a grid step. Moreover, it is easier to implement and more adaptable. finally, two subgrid-scale models are tested： the WALE model of Nic0ud and Ducros （flow Turbul. Combust., vol. 62, 1999） and the shear-improved Smagorinsky model of Ldv^que et al. （j. fluid Mech., vol. 570, 2007）. Both models allow transition, but the former appears to yield a faster transition and a better prediction of friction in the turbulent regime.

关键词： large-eddy simulation boundary layer roughness element transition tripping

A linear regression model (LRM) for groundwater chemistry in and around the Vaniyambadi industrial area, Tamil Nadu, India

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Chinese journal Of Geochemistry 2013年第1期32卷 19-26页

作者： Sajil Kumar P.j. davis Delson P. Vernon j.G. james E.j. Brandenburg Technical University Cottbus-03046 Germany ITALCONSULT Riyadh-11421 Saudi Arabia Budapest University of Technology and Economics (BME) Budapest-Pf. 91 H-152 Hungary Water Institute Karunya UniversityCoimbatore-641114 India

A linear regression model in conjunction with cluster analysis was applied to the groundwater quality parameters for the Vaniyambadi industrial area, Tamil Nadu, India. These physico-chemical parameters were collected from 25 wells by intensive groundwater sampling conducted during january 2010. All the major ions, pH and electrical conductivity were analyzed. The abundances of cations were in the order of Na f anions were in the order of Cl f the ions Na, Cl and SO4 were recorded near the tanneries that operate within the study area. While the elevated concentrations of HCO3 and f were observed away from the tanneries. This peculiar hydrochemical behaviour suggests that the chemistry of water is predominantly influenced by tannery effluents and weathering of silicate minerals. Results of the linear regression model yielded 11 regression equations for the 5 most correlated parameters. A dendrogram from the cluster analysis showed 2 major clusters representing the influence of tanneries and geological formations in the study area, which confirmed the results of major ion chemistry.

关键词：线性回归模型地下水化学工业区印度 LRM 聚类分析物理化学参数研究区域

INVESTIGATION Of THE ATRP Of n-BUTYL METHACRYLATE USING THE Cu(I)/N,N,N',N",N"-PENTAMETHYLDIETHYLENETRIAMINE CATALYST SYSTEM

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Chinese journal of Polymer Science 2004年第2期22卷 195-204页

作者： Kelly A. davis Krzysztof Matyjaszewski Center for Macromolecular Engineering Department of Chemistry Carnegie Mellon University 4400 Fifth Ave.Pittsburgh Pennsylvania 15213 USACenter for Macromolecular Engineering Department of Chemistry Carnegie Mellon University 4400 Fifth Ave.Pittsburgh Pennsylvania 15213 USA

The polymerization of n-butyl methacrylate was investigated using the Atom Transfer Radical Polymerization technique with CuBr and CuCl/N,N,N',N',N'-pentamethyldiethylenetriamine catalytic systems. Various combinations of catalyst systems and initiators were utilized in order to optimize the polymerization conditions and to obtain well-defined polymers (i.e. controlled molecular weights and low polydispersities). It has been found that the optimal initiator for this system is a chlorine-based initiator, when the catalyst used is a salt in conjunction with the N,N,N',N',N'- pentamethyldiethylenetriamine ligand. Bromine-based initiators tend to result in large amounts of initial termination, leading to polymers with less than ideal chain end functionality, even if CuCl is used as the species to invoke the halogen exchange. Additionally, the effects of the polymerization temperature, species and the initiator structure were determined.

关键词： ATRP Atom transfer radical polymerization Controlled/living radical polymerization Butyl methacrylate Pentamethyldiethylenetriamine

Machine-learned impurity level prediction for semiconductors:the example of Cd-based chalcogenides

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npj Computational Materials 2020年第1期6卷 1346-1359页

作者： Arun Mannodi-Kanakkithodi Michael Y.Toriyama fatih G.Sen Michael j.davis Robert f.Klie Maria K.Y.Chan Center for Nanoscale Materials Argonne National LaboratoryArgonneIL 60439USA Chemical Sciences and Engineering Division Argonne National LaboratoryArgonneIL 60439USA Department of Physics University of Illinois at ChicagoChicagoIL 60607USA

The ability to predict the likelihood of impurity incorporation and their electronic energy levels in semiconductors is crucial for controlling its conductivity,and thus the semiconductor’s performance in solar cells,photodiodes,and *** difficulty and expense of experimental and computational determination of impurity levels makes a data-driven machine learning approach *** this work,we show that a density functional theory-generated dataset of impurities in Cd-based chalcogenides CdTe,CdSe,and CdS can lead to accurate and generalizable predictive models of defect properties.

关键词： semiconductors prediction impurity