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Sample records for grade high strength

  1. Advanced High Tensile Strength Steel of 100 kgf/mm^2 Grade for Penstock Use

    OpenAIRE

    Ryuji, SHIMODA; Toshihiko, MATSUURA; Yoshihiro, KURE; Itaru, WATANABE; Motoaki, SUZUKI; Shin, SAKUI; Sakai Iron Works Co., Ltd.; Sakai Iron Works Co., Ltd.; Sakai Iron Works Co., Ltd.; Nippon Kokan K.K.; Nippon Kokan K.K.; Nippon Kokan K.K.

    1987-01-01

    The applicability of a 100 kgf/mm^2 grade high tensile strength steel developed for penstock was evaluated in this paper. Firstly, Jive kinds of weld cracking tests were performed and it was demonstrated that the 100 kgf/mm^2 grade steel, including its weld metal, has a good resistance to cold cracking. Secondly, its mechanical properties and fracture toughness were investigated and evaluated the safety of its weldment against brittle fracture. Finally, the correlation between its fracture to...

  2. Fatigue of Austempered Ductile Iron with Two Strength Grades in Very High Cycle Regime

    Science.gov (United States)

    Zhang, Jiwang; Li, Wei; Song, Qingpeng; Zhang, Ning; Lu, Liantao

    2016-03-01

    In this study, Austempered ductile irons (ADIs) with two different strength grades were produced and the fatigue properties were measured at 109 cycles. The results show that the S-N curves give a typical step-wise shape and there is no fatigue limit in the very high cycle fatigue regime. The two grades ADI have the similar fracture behaviors and fatigue failure can initiate from defects at specimen surface and subsurface zone. On the fracture surfaces of some specimens, the `granular-bright-facet' area with rich carbon distribution is observed in the vicinity of the defect. The microstructure affects the crack behaviors at the early propagation stage. The ADI with upper and lower bainite shows higher fatigue strength compared with the ADI with coarse upper bainite.

  3. Development of high strength pipes grade API 5L X70 PSL2 offshore by the HFIW Process (High Frequency Induction Welding)

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, Wilson R.; Melo, Luis C.R.; Gomes, Igor O.; Boni, Luiz P.; Sanctis, Marco A.M. di [Apolo Tubulars, Lorena, SP (Brazil)

    2009-07-01

    High strength pipes can be manufactured with excellency in dimensional tolerances, rapidity and efficiency through HFIW process (High Frequency Induction Welding). API 5L 6 5/8 x 0,374 in pipes were made of thin, hot rolled and coiled plates with dimensional 9,300 x 1.040,0 x 140.000 mm. Mechanical tests, chemical and microstructural analysis were performed. For the microstructural analysis, ferrite and perlitic structure were detected. All the results obtained are according to API 5L, 44{sup th} edition, 2008 for the grade API 5L X70 PSL2 Offshore. (author)

  4. Prediction Model of Cutting Parameters for Turning High Strength Steel Grade-H: Comparative Study of Regression Model versus ANFIS

    Directory of Open Access Journals (Sweden)

    Adel T. Abbas

    2017-01-01

    Full Text Available The Grade-H high strength steel is used in the manufacturing of many civilian and military products. The procedures of manufacturing these parts have several turning operations. The key factors for the manufacturing of these parts are the accuracy, surface roughness (Ra, and material removal rate (MRR. The production line of these parts contains many CNC turning machines to get good accuracy and repeatability. The manufacturing engineer should fulfill the required surface roughness value according to the design drawing from first trail (otherwise these parts will be rejected as well as keeping his eye on maximum metal removal rate. The rejection of these parts at any processing stage will represent huge problems to any factory because the processing and raw material of these parts are very expensive. In this paper the artificial neural network was used for predicting the surface roughness for different cutting parameters in CNC turning operations. These parameters were investigated to get the minimum surface roughness. In addition, a mathematical model for surface roughness was obtained from the experimental data using a regression analysis method. The experimental data are then compared with both the regression analysis results and ANFIS (Adaptive Network-based Fuzzy Inference System estimations.

  5. A study on the strength of an armour-grade aluminum under high strain-rate loading

    Science.gov (United States)

    Appleby-Thomas, G. J.; Hazell, P. J.

    2010-06-01

    The aluminum alloy 5083 in tempers such as H32 and H131 is an established light-weight armour material. While its dynamic response under high strain-rates has been investigated elsewhere, little account of the effect of material orientation has been made. In addition, little information on its strength under such loadings is available in the literature. Here, both the longitudinal and lateral components of stress have been measured using embedded manganin stress gauges during plate-impact experiments on samples with the rolling direction aligned both orthogonal and parallel to the impact axis. The Hugoniot elastic limit, spall, and shear strengths were investigated for incident pressures in the range 1-8 GPa, providing an insight into the response of this alloy under shock loading. Further, the time dependence of lateral stress behind the shock front was investigated to give an indication of material response.

  6. Nondestructive Strength Grading of Structural Timber

    Directory of Open Access Journals (Sweden)

    P. Kuklík

    2000-01-01

    Full Text Available The paper is concerned with the investigation of the use of non-destructive testing methods for the grading of structural timber and for the determination of the performance of structural timber elements. The investigations dealt with the ultrasonic method and the methods of longitudinal and transverse vibrations. The usability of these methods was verified at samples with the structural dimensions. The principle of the work lies in the search for statistic relationships between parameters characterising the timber quality (e.g. bending strength, modulus of elasticity and magnitudes measured by the above mentioned non-destructive testing methods (e.g. natural frequency, dynamic modulus of elasticity.

  7. High strength ferritic alloy

    International Nuclear Information System (INIS)

    1977-01-01

    A high strength ferritic steel is specified in which the major alloying elements are chromium and molybdenum, with smaller quantities of niobium, vanadium, silicon, manganese and carbon. The maximum swelling is specified for various irradiation conditions. Rupture strength is also specified. (U.K.)

  8. Microstructural Characterization and Mechanical Properties of Electron Beam Welded Joint of High Strength Steel Grade S690QL

    Directory of Open Access Journals (Sweden)

    Błacha S.

    2016-06-01

    Full Text Available In the paper the results of metallographic examination and mechanical properties of electron beam welded joint of quenched and tempered steel grade S690QL are presented. Metallographic examination revealed that the concentrated electron beam significantly affect the changes of microstructure in the steel. Parent material as a delivered condition (quenched and tempered had a bainitic-martensitic microstructure at hardness about 290 HV0.5. After welding, the microstructure of heat affected zone is composed mainly of martensite (in the vicinity of the fusion line of hardness 420 HV0.5. It should be noted, however, that the microstructure of steel in the heat affected zone varies with the distance from the fusion line. The observed microstructural changes were in accordance with the CCT-S transformation diagram for the examined steel.

  9. Species independent strength grading of structural timber

    NARCIS (Netherlands)

    Ravenshorst, G.J.P.

    2015-01-01

    Timber as a construction material has been used for millennia, but the research field covering the prediction of the strength of structural timber is still in development. Currently, the common conception is that the determination of strength properties has to be determined for every wood species

  10. Structure–property relationship in a 960 MPa grade ultrahigh strength low carbon niobium–vanadium microalloyed steel: The significance of high frequency induction tempering

    International Nuclear Information System (INIS)

    Xie, Z.J.; Fang, Y.P.; Han, G.; Guo, H.; Misra, R.D.K.; Shang, C.J.

    2014-01-01

    The present study describes the microstructure and precipitation behavior in an ultra-high strength low carbon niobium–vanadium microalloyed steel that was processed by quenching and high frequency induction tempering. Ultrahigh yield strength of ∼1000 MPa with high elongation of ∼15% and high low temperature toughness of 55 J (half thickness) at −40 °C was obtained after quenching from austenitization at 900 °C for 30 min, and tempering at 600 °C for 15 min by induction reheating with a reheating rate of ∼50 °C/s. While the yield strength increase on tempering was similar for both induction reheating and conventional reheating (electrical resistance reheating), there was ∼100% increase in low temperature toughness in induction reheated steel compared to the conventional reheating process. The underlying reason for the increase in toughness was attributed to the transformation of cementite film observed in conventional reheating and tempering to nanoscale cementite in induction reheating and tempering. The precipitation of nanoscale carbides is believed to significantly contribute to ultra-high strength, good ductility, and high toughness in the high frequency induction reheating and tempering process

  11. Microstructure Evolution and Mechanical Properties of Underwater Dry and Local Dry Cavity Welded Joints of 690 MPa Grade High Strength Steel

    Science.gov (United States)

    Sun, Kun; Cui, Shuwan; Zeng, Min; Yi, Jianglong; Shen, Xiaoqin; Yi, Yaoyong

    2018-01-01

    Q690E high strength low alloy (HSLA) steel plays an important role in offshore structures. In addition, underwater local cavity welding (ULCW) technique was widely used to repair important offshore constructions. However, the high cooling rate of ULCW joints results in bad welding quality compared with underwater dry welding (UDW) joints. Q690E high strength low alloy steels were welded by multi-pass UDW and ULCW techniques, to study the microstructural evolution and mechanical properties of underwater welded joints. The microstructure and fracture morphology of welded joints were observed by scanning electron microscope and optical microscope. The elemental distribution in the microstructure was determined with an Electron Probe Microanalyzer. The results indicated that the microstructure of both two welded joints was similar. However, martensite and martensite-austenite components were significantly different with different underwater welding methods such that the micro-hardness of the HAZ and FZ in the ULCW specimen was higher than that of the corresponding regions in UDW joint. The yield strength and ultimate tensile strength of the ULCW specimen are 109 MPa lower and 77 MPa lower, respectively, than those of the UDW joint. The impact toughness of the UDW joint was superior to those of the ULCW joint. PMID:29361743

  12. Microstructure Evolution and Mechanical Properties of Underwater Dry and Local Dry Cavity Welded Joints of 690 MPa Grade High Strength Steel.

    Science.gov (United States)

    Shi, Yonghua; Sun, Kun; Cui, Shuwan; Zeng, Min; Yi, Jianglong; Shen, Xiaoqin; Yi, Yaoyong

    2018-01-22

    Q690E high strength low alloy (HSLA) steel plays an important role in offshore structures. In addition, underwater local cavity welding (ULCW) technique was widely used to repair important offshore constructions. However, the high cooling rate of ULCW joints results in bad welding quality compared with underwater dry welding (UDW) joints. Q690E high strength low alloy steels were welded by multi-pass UDW and ULCW techniques, to study the microstructural evolution and mechanical properties of underwater welded joints. The microstructure and fracture morphology of welded joints were observed by scanning electron microscope and optical microscope. The elemental distribution in the microstructure was determined with an Electron Probe Microanalyzer. The results indicated that the microstructure of both two welded joints was similar. However, martensite and martensite-austenite components were significantly different with different underwater welding methods such that the micro-hardness of the HAZ and FZ in the ULCW specimen was higher than that of the corresponding regions in UDW joint. The yield strength and ultimate tensile strength of the ULCW specimen are 109 MPa lower and 77 MPa lower, respectively, than those of the UDW joint. The impact toughness of the UDW joint was superior to those of the ULCW joint.

  13. A comparison between ultra-high-strength and conventional high-strength fastener steels : Mechanical properties at elevated temperature and microstructural mechanisms

    NARCIS (Netherlands)

    Ohlund, C.E.I.C.; Lukovic, M.; Weidow, J; Thuvander, M; Offerman, S.E.

    2016-01-01

    A comparison is made between the mechanical properties of the ultra-high-strength steel KNDS4 of fastener grade 14.9 and of conventional, high-strength steels 34Cr4 of fastener grade 12.9 and 33B2 of grade 10.9. The results show that the ratio of the yield strength at elevated temperatures to the

  14. [GRADE system: classification of quality of evidence and strength of recommendation].

    Science.gov (United States)

    Aguayo-Albasini, José Luis; Flores-Pastor, Benito; Soria-Aledo, Víctor

    2014-02-01

    The acquisition and classification of scientific evidence, and subsequent formulation of recommendations constitute the basis for the development of clinical practice guidelines. There are several systems for the classification of evidence and strength of recommendations; the most commonly used nowadays is the Grading of Recommendations, Assessment, Development and Evaluation system (GRADE). The GRADE system initially classifies the evidence into high or low, coming from experimental or observational studies; subsequently and following a series of considerations, the evidence is classified into high, moderate, low or very low. The strength of recommendations is based not only on the quality of the evidence, but also on a series of factors such as the risk/benefit balance, values and preferences of the patients and professionals, and the use of resources or costs. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

  15. The Bendability of Ultra High strength Steels

    Science.gov (United States)

    Hazra, S. K.; Efthymiadis, P.; Alamoudi, A.; Kumar, R. L. V.; Shollock, B.; Dashwood, R.

    2016-08-01

    Automotive manufacturers have been reducing the weight of their vehicles to meet increasingly stringent environmental legislation that reflects public demand. A strategy is to use higher strength materials for parts with reduced cross-sections. However, such materials are less formable than traditional grades. The frequent result is increased processing and piece costs. 3D roll forming is a novel and flexible process: it is estimated that a quarter of the structure of a vehicle can be made with a single set of tooling. Unlike stamping, this process requires material with low work hardening rates. In this paper, we present results of ultra high strength steels that have low elongation in a tension but display high formability in bending through the suppression of the necking response.

  16. Development of TS590MPa grade high tensile strength steel for automotive anti-collision parts; Shogeki kyushuyo 590MPa kyu kochoryoku koban no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Miura, K.; Takagi, S.; Furukimi, O.; Hira, T.; Obara, T. [Kawasaki Steel Corp., Tokyo (Japan); Tanimura, S. [University of Osaka Prefecture, Osaka (Japan)

    1997-10-01

    The effects of strain rate on the deformation behavior of steels were investigated to find the most appropriate micro-structure of steel for anti-crash parts of automobiles, such as front-side-members. The dual phase steel absorbed a higher amount of energy during dynamic deformation than other steels with the same static yield strength. The increase of volume fraction of the austenite phase in the dual phase steel deteriorates the dynamic deformation behavior. The FEM analysis for crash test of HAT-sectional sheet box also showed the superior performance of the dual phase steel. 4 refs., 7 figs., 1 tab.

  17. Development of high strength, high temperature ceramics

    Science.gov (United States)

    Hall, W. B.

    1982-01-01

    Improvement in the high-pressure turbopumps, both fuel and oxidizer, in the Space Shuttle main engine were considered. The operation of these pumps is limited by temperature restrictions of the metallic components used in these pumps. Ceramic materials that retain strength at high temperatures and appear to be promising candidates for use as turbine blades and impellers are discussed. These high strength materials are sensitive to many related processing parameters such as impurities, sintering aids, reaction aids, particle size, processing temperature, and post thermal treatment. The specific objectives of the study were to: (1) identify and define the processing parameters that affect the properties of Si3N4 ceramic materials, (2) design and assembly equipment required for processing high strength ceramics, (3) design and assemble test apparatus for evaluating the high temperature properties of Si3N4, and (4) conduct a research program of manufacturing and evaluating Si3N4 materials as applicable to rocket engine applications.

  18. STRENGTH OF NANOMODIFIED HIGH-STRENGTH LIGHTWEIGHT CONCRETES

    Directory of Open Access Journals (Sweden)

    NOZEMTСEV Alexandr Sergeevich

    2013-02-01

    Full Text Available The paper presents the results of research aimed at development of nanomodified high-strength lightweight concrete for construction. The developed concretes are of low average density and high ultimate compressive strength. It is shown that to produce this type of concrete one need to use hollow glass and aluminosilicate microspheres. To increase the durability of adhesion between cement stone and fine filler the authors offer to use complex nanodimensinal modifier based on iron hydroxide sol and silica sol as a surface nanomodifier for hollow microspheres. It is hypothesized that the proposed modifier has complex effect on the activity of the cement hydration and, at the same time increases bond strength between filler and cement-mineral matrix. The compositions for energy-efficient nanomodified high-strength lightweight concrete which density is 1300…1500 kg/m³ and compressive strength is 40…65 MPa have been developed. The approaches to the design of high-strength lightweight concrete with density of less than 2000 kg/m³ are formulated. It is noted that the proposed concretes possess dense homogeneous structure and moderate mobility. Thus, they allow processing by vibration during production. The economic and practical implications for realization of high-strength lightweight concrete in industrial production have been justified.

  19. Advanced high strength steels for automotive industry

    Directory of Open Access Journals (Sweden)

    Galán, J.

    2012-04-01

    Full Text Available The car industry is facing pressure because of the growing demand for more fuel-efficient passenger cars. In order to limit energy consumption and air pollution the weight of the carbody has to be reduced. At the same time, high levels of safety have to be guaranteed. In this situation, the choice of material becomes a key decision in car design. As a response to the requirements of the automotive sector, high strength steels and advanced high strength steels have been developed by the steel industry. These modern steel grades offer an excellent balance of low cost, light weight and mechanical properties.

    La industria del automóvil se enfrenta a una creciente demanda de vehículos de pasajeros más eficientes. Con el fin de disminuir el consumo de energía y la contaminación ambiental, el peso del vehículo tiene que ser reducido, al mismo tiempo que se garantizan altos niveles de seguridad. Ante esta situación, la elección de material se convierte en una decisión crucial en el diseño del vehículo. Como respuesta a las necesidades del sector automovilístico, nuevos aceros avanzados y de alta resistencia, han sido desarrollados por la industria siderúrgica. Dichos tipos de acero ofrecen un excelente equilibrio de precio, peso y propiedades mecánicas.

  20. High Strength Steel Welding Research

    National Research Council Canada - National Science Library

    Edwards, Glen

    1998-01-01

    .... These electrodes were insensitive to moderate variations in chemical composition or cooling rate, had acceptable strength and impact toughness, and exhibited more uniform mechanical properties...

  1. Using 4+ to grade near-normal muscle strength does not improve agreement

    DEFF Research Database (Denmark)

    O'Neill, Søren; Jaszczak, Sofie Louise Thomsen; Steffensen, Anne Katrine Søndergaard

    2017-01-01

    Manual assessment of muscle strength is often graded using the ordinal Medical Research Council (MRC) scale. The scale has a number of inherent weaknesses, including poorly defined limits between grades `4' and `5' and very large differences in the span of muscle strength encompassed by each...... of the six grades. It is not necessarily obvious how to convert a manual muscle test finding into an MRC grade. Several modifications which include intermediate grades have been suggested to improve the MRC scale and the current study examines whether agreement improves and variation in ratings decrease...

  2. Hydrogen Assisted Cracking of High Strength Alloys

    National Research Council Canada - National Science Library

    Gangloff, Richard P

    2003-01-01

    ... (Irwin and Wells, 1997; Paris, 1998). Second, materials scientists developed metals with outstanding balances of high tensile strength and high fracture toughness (Garrison, 1990; Wells, 1993; Boyer, 1993...

  3. Prediction of Torsional Strength for Very High Early Strength Geopolymer

    Directory of Open Access Journals (Sweden)

    Woraphot PRACHASAREE

    2017-11-01

    Full Text Available Very early high strength geopolymers are gaining acceptance as alternative repair materials for highways and other infrastructure. In this study, a very rapid geopolymer binder based on Metakaolin (MK and Parawood ash (PWA, developed by the authors, was experimentally tested and a prediction model for its torsional strength is proposed. The geopolymer samples were subjected to uniaxial compression, flexural beam, and torsion tests. The modulus of rupture and torsional strength in terms of compression strength were found to be well approximated by 0.7(f’c1/2 and 1/7(x2y (f’c1/2, respectively. Also an interaction relation to describe combined bending and torsion was developed in this study. In addition, the effects of aspect ratio (y/x were studied on both torsional strength and combined bending and torsion. It was found that an aspect ratio of y/x = 3 significantly reduced the torsional resistance, to about 50 % of the torsional strength of a square section.DOI: http://dx.doi.org/10.5755/j01.ms.23.4.17280

  4. Using 4+ to grade near-normal muscle strength does not improve agreement

    DEFF Research Database (Denmark)

    O'Neill, Søren; Jaszczak, Sofie Louise Thomsen; Steffensen, Anne Katrine Søndergaard

    2017-01-01

    Manual assessment of muscle strength is often graded using the ordinal Medical Research Council (MRC) scale. The scale has a number of inherent weaknesses, including poorly defined limits between grades `4' and `5' and very large differences in the span of muscle strength encompassed by each...... of the six grades. It is not necessarily obvious how to convert a manual muscle test finding into an MRC grade. Several modifications which include intermediate grades have been suggested to improve the MRC scale and the current study examines whether agreement improves and variation in ratings decrease......, with an intermediate grade between `4' and `5', in circumstances where such a grade would seem appropriate. The present study examined the hypothesis, that a modified MRC-scale which included the commonly used `4+' option, resulted in greater agreement between clinicians compared to the standard MRC-scale....

  5. The Construction of a Muscular Strength Test Battery for Girls in the Primary Grades.

    Science.gov (United States)

    DiNucci, James M.; Pelton, Elois B.

    This study was designed to construct a gross muscular strength test battery for girls 6-9 years of age in grades 1-3. The subjects for this investigation were a random sample of 183 girls in grades 1-3 of the public schools of Natchitoches, Louisiana. The variables selected were 22 cable tension strength tests developed by Clarke and associates.…

  6. Bending strength of shallow glued-laminated beams of a uniform grade

    Science.gov (United States)

    Catherine M. Marx; Russell C. Moody

    1981-01-01

    Ninety glued-laminated Douglas-fir or southern pine beams of a uniform grade with 2-, 4-, or 6-laminations were evaluated in static bending tests. No specially graded tension laminations or end joints were used. The purpose of the tests was to determine which of three present design criteria best predict near minimum bending strength values for shallow glued-laminated...

  7. Formability Characterization of a New Generation High Strength Steels

    Energy Technology Data Exchange (ETDEWEB)

    Sriram Sadagopan; Dennis Urban; Chris Wong; Mai Huang; Benda Yan

    2003-05-16

    Advanced high strength steels (AHSS) are being progressively explored by the automotive industry all around the world for cost-effective solutions to accomplish vehicle lightweighting, improve fuel economy, and consequently reduce greenhouse emissions. Because of their inherent high strength, attractive crash energy management properties, and good formability, the effective use of AHSS such as Duel Phase and TRIP (Transformation Induced Plasticity) steels, will significantly contribute to vehicle lightweighting and fuel economy. To further the application of these steels in automotive body and structural parts, a good knowledge and experience base must be developed regarding the press formability of these materials. This project provides data on relevant intrinsic mechanical behavior, splitting limits, and springback behavior of several lots of mild steel, conventional high strength steel (HSS), advanced high strength steel (AHSS) and ultra-high strength steel (UHSS), supplied by the member companies of the Automotive Applications Committee (AAC) of the American Iron and Steel Institute (AISI). Two lots of TRIP600, which were supplied by ThyssenKrupp Stahl, were also included in the study. Since sheet metal forming encompasses a very diverse range of forming processes and deformation modes, a number of simulative tests were used to characterize the forming behavior of these steel grades. In general, it was found that formability, as determined by the different tests, decreased with increased tensile strength. Consistant with previous findings, the formability of TRIP600 was found to be exceptionally good for its tensile strength.

  8. The effect of microstructure and strength on the fracture toughness of an 18 Ni, 300 grade maraging steel

    Science.gov (United States)

    Psioda, J. A.; Low, J. R., Jr.

    1975-01-01

    A 300 grade maraging steel was chosen as a vehicle by which to understand the inverse relationship between strength and toughness in high strength alloys such as the 18 Ni maraging steels. The 18 Ni, 300 grade maraging material was a commercial grade consumable-electrode, vacuum arc remelted heat obtained in the form of forged and annealed plate. The matrix contained a population of second-phase impurity inclusions which was a product of the casting and hot working processes. These inclusions did not change with subsequent precipitation hardening. Changes in microstructure resulting in strength increases were brought about by variations in aging temperature and time. Maximum strength was attained in the 300 grade maraging steel by aging at 427 C (800 F) for 100 hours. Tensile, fatigue precracked Charpy impact, and plane-strain fracture toughness tests were performed at room temperature, 20 C (68 F). With increasing strength the fracture toughness decreases as smaller and smaller inclusions act as sites for void initiation.

  9. High Purity Smelting Technology for Ultra-high Strength Steels

    Directory of Open Access Journals (Sweden)

    JIANG Zhouhua

    2017-12-01

    Full Text Available Ultra-high strength steel with high tensile strength, good toughness, high specific strength, modulus and other characteristics are widely used in aviation, aerospace and national defense and other fields. Ultra-high strength steel is preferred material for aircraft and aero-engines and other aviation equipments. The application of ultra-high strength steel represents a country's highest level of steel research and production, and it is also an important symbol of the development of national science and technology and national defense industry. The development and application of high purity smelting technology for manufacture of ultra-high strength steels at domestic and overseas is briefly reviewed in the paper, and then the control ability about the impurity elements such as S, P, O and N in typical ultra-high strength steels, and the research status and development trend of non-metallic inclusions control are discussed. The progress in research work of high purity smelting technology for ultra-high strength steels carried out by the authors in recent years has been introduced, it shows that the control level of impurity elements and non-metallic inclusion has been greatly improved, and it also creates a new route for China to manufacture the ultra-high strength steel with high alloy, especially with high purity for ultra-high strength stainless steel, bearing steel and gear steel. Finally, the development direction of high purity smelting technology of ultra-high strength steel in China is pointed out.

  10. Construction and assembly of pipelines using API 5L grade X80 tubes - considerations to be observed with high-strength steels; Construcao e montagem de dutos terrestres utilizando tubos API 5L Gr. X80

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ailton C. de; Rabello, Jose Mauricio B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The use of line pipes API 5L Grade X80, at the point of view of designer allows: reduction of wall thickness and pipe weight or increase of design pressure. In the pipeline construction point of view, the use of line pipes API 5L Grade X80 provide some advantages, however some difficulties must be expected in several stages of the construction and assembly. The implications in cost, productivity, inspection and integrity, with the application of these high resistance steels, complying with PETROBRAS Standard N - 464 Construcao, Montagem e Condicionamento de Dutos Terrestres (Rev. H - 2004 Dec) and the experience consolidated in pipelines construction abroad were presented. At the design stage, a comparison between pipelines designed using API 5L-X70 and API 5L-X80 was carried out approaching the aspects of variation of thickness, pressure design and design factor. An evaluation of the expected gains when choosing API 5L Grade X80 steels were done, regarding reduction of costs and pipe weight. Regarding API 5L-X80 pipe fabrication, the obtained results were reported, proving that this aspect was already overcome, showing the viability of its production in Brazil. Difficulties were detected regarding construction and assembly stage and showing the need of revision of PETROBRAS standard N-464. (author)

  11. Application of ANFIS for analytical modeling of tensile strength of functionally graded steels

    Directory of Open Access Journals (Sweden)

    Ali Nazari

    2012-06-01

    Full Text Available In the present study, the tensile strength of ferritic and austenitic functionally graded steels produced by electroslag remelting has been modeled. To produce functionally graded steels, two slices of plain carbon steel and austenitic stainless steels were spot welded and used as electroslag remelting electrode. Functionally graded steel containing graded layers of ferrite and austenite may be fabricated via diffusion of alloying elements during remelting stage. Vickers microhardness profile of the specimen has been obtained experimentally and modeled with adaptive network-based fuzzy inference systems (ANFIS. To build the model for graded ferritic and austenitic steels, training, testing and validation using respectively 174 and 120 experimental data were conducted. According to the input parameters, in the ANFIS model, the Vickers microhardness of each layer was predicted. A good fit equation which correlates the Vickers microhardness of each layer to its corresponding chemical composition was achieved by the optimized network for both ferritic and austenitic graded steels. Afterwards; the Vickers microhardness of each layer in functionally graded steels was related to the yield stress of the corresponding layer and by assuming Holloman relation for stress-strain curve of each layer, they were acquired. Finally, by applying the rule of mixtures, tensile strength of functionally graded steels configuration was found through a numerical method. The obtained results from the proposed model are in good agreement with those acquired from the experiments.

  12. Improvement of strength characteristics of lateritic sub-grade soil ...

    African Journals Online (AJOL)

    Shredded high density polyethylene High Density Polyethylene Waste of maximum size 20 × 25mm was used for the improvement of lateritic soil at various percentages which are; 1%, 2%, 3%, 4%, and 5% respectively. Series of laboratory tests such as, Compaction and California Bearing Ratio (CBR) were conducted to ...

  13. Tensile properties of machine strength graded timber for glued laminated timber

    DEFF Research Database (Denmark)

    Boström, Lars; Hoffmeyer, Preben; Solli, Kjell-Helge

    1999-01-01

    Special setting values based on tensile properties of Norway spruce are established for four different strength grading machines. The machines included are Computermatic, Cook-Bolinder, Ersson and Dynagrade.The study shows that the yield of timber to be used in tension, such as laminations...... for glulam, may be increased by basing the setting values on test results of the tensile properties rather than using the strength classes definen in EN338....

  14. Experiments and fracture modeling of high-strength pipelines for high and low stress triaxialities

    NARCIS (Netherlands)

    Walters, C.L.; Kofiani, K.; Nonn, A.; Wierzbicki, T.; Kalwa, C.

    2012-01-01

    This paper provides results from a comprehensive study on mechanical characterization of high-strength pipeline steel, grade X100 using experimental and numerical methods. The material was characterized for anisotropic plasticity, fracture initiation for various states of stress, (pre-cracked)

  15. Development of high strength high toughness third generation advanced high strength steels

    Science.gov (United States)

    Martis, Codrick John

    Third generation advanced high strength steels (AHSS's) are emerging as very important engineering materials for structural applications. These steels have high specific strength and thus will contribute significantly to weight reduction in automotive and other structural component. In this investigation two such low carbon low alloy steels (LCLA) with high silicon content (1.6-2wt %) has been developed. These two steel alloys were subjected to single step and two step austempering in the temperature range of 260-399°C to obtain desired microstructures and mechanical properties. Austempering heat treatment was carried out for 2 hours in a molten salt bath. The microstructures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and optical metallography. Quantitative analysis was carried out by image analysis technique. The effect of austempering temperature on the mechanical properties of these two alloys was examined. The influence of microstructures on the mechanical properties of alloys was also studied. Austempering heat treatment resulted in fine carbide free bainitic ferrite and high carbon austenite microstructure in the samples austempered above Ms temperature, whereas tempered martensite and austenite microstructure was obtained in samples austempered below Ms temperature. Yield strength, tensile strength and fracture toughness were found to increase as the austempering temperature decreases, whereas ductility increases as the austempering temperature increases. Tensile strength in the range of 1276MPa -1658 MPa and the fracture toughness in the range of 80-141MPa√m were obtained in these two steels. Volume fractions of different phases present and their lath sizes are related to the mechanical properties. Austempered samples consisting of mixed microstructure of bainitic ferrite and tempered martensite phases resulted in the exceptional combination of strength and toughness.

  16. High grade magnesium from waste bittern

    International Nuclear Information System (INIS)

    El-Yamani, I.S.; Farah, M.Y.; Isaac, S.L.

    1979-01-01

    The production of high grade magnesia for nuclear purposes from sea water by use of both aqueous and gaseous ammonia has been described. The effect of precipitating conditions on the settling rate and magnesium recovery, was thoroughly examined. Ammonia gas approach was recommended and justified

  17. High strength reinforcing steel bars : concrete shear friction interface : final report : Part A.

    Science.gov (United States)

    2017-03-01

    High-strength steel (HSS) reinforcement, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) steel reinf...

  18. Design of Reforma 509 with High Strength Steel

    Science.gov (United States)

    Smith, Stuart; Whitby, William; Easton, Marc

    Reforma 509 is a high-rise building located in the heart of the Central Business District of Mexico City. The building is comprised of office, hotel, residential and parking and forms part of a cluster of tall buildings in the area. If completed today, Reforma 509 would be the tallest building in Mexico, at 238m. All of the building's gravity and lateral (wind and seismic) loads are carried by an architecturally expressed perimeter frame that is formed from highly efficient Steel Reinforced Concrete (SRC) columns coupled together by steel tube perimeter bracing. This paper investigates the implications of substituting a grade 50 (fy=345 MPa) carbon steel with a higher strength micro-alloyed grade 70 (fy=480 MPa) steel in the design of Reforma 509.

  19. High early strength latex modified concrete overlay.

    Science.gov (United States)

    1988-01-01

    This report describes the condition of the first high early strength latex modified concrete (LMC-HE) overlay to be constructed for the Virginia Department of Transportation. The overlay was prepared with type III cement and with more cement and less...

  20. Numerical Model of High Strength Concrete

    Science.gov (United States)

    Wang, R. Z.; Wang, C. Y.; Lin, Y. L.

    2018-03-01

    The purpose of this paper is to present a three-dimensional constitutive model based on the concept of equivalent uniaxial strain. closed Menetrey-Willam (CMW) failure surfaces which combined with Menetrey-Willam meridian and the cap model are introduced in this paper. Saenz stress-strain model is applied and adjusted by the ultimate strength parameters from CMW failure surface to reflect the latest stress or strain condition. The high strength concrete (HSC) under tri-axial non-proportional loading is considered and the model in this paper performed a good prediction.

  1. Low-grade and high-grade endometrial stromal sarcoma: A National Cancer Database study.

    Science.gov (United States)

    Seagle, Brandon-Luke L; Shilpi, Arunima; Buchanan, Samuel; Goodman, Chelain; Shahabi, Shohreh

    2017-08-01

    To provide refined prognostic information from large cohorts of women with low-grade or high-grade endometrial stromal sarcoma (ESS). We performed an observational retrospective cohort analysis of women diagnosed with low-grade or high-grade ESS from the 1998-2013 National Cancer Database. Kaplan-Meier and multivariable accelerated failure time survival analyses were performed to identify prognostic factors after multiple imputation of missing data. Recursive partitioning methods were used to rank prognostic factors in high-grade ESS. Matched cohort analyses were performed to hypothesis-test effects of adjuvant treatments. We identified 2414 and 1383 women with low-grade or high-grade ESS, respectively. Women with high-grade ESS had markedly decreased survival compared to women with low-grade ESS (five-year survival (95% CI): 32.6 (30.1-35.3%) versus 90.5% (89.3-91.8%), PTR) (95% CI): 1.36 (1.17-1.58), PTR (95% CI): 1.57 (1.32-1.87), P<0.001) were associated with increased survival for high-grade ESS. The contrasting excellent versus poor prognosis of low-grade versus high-grade ESS, respectively, was confirmed. The best treatment of high-grade ESS is early and complete surgical resection including lymphadenectomy. Adjuvant chemotherapy and radiotherapy may increase survival of women with high-grade ESS. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Making High-Tensile-Strength Amalgam Components

    Science.gov (United States)

    Grugel, Richard

    2008-01-01

    Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room-temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles. Heretofore, the powder particles used to make amalgams have been, variously, in the form of micron-sized spheroids or flakes. The tensile reinforcement contributed by the spheroids and flakes is minimal because fracture paths simply go around these particles. However, if spheroids or flakes are replaced by strands having greater lengths, then tensile reinforcement can be increased significantly. The feasibility of this concept was shown in an experiment in which electrical copper wires, serving as demonstration substitutes for copper powder particles, were triturated with gallium by use of a mortar and pestle and the resulting amalgam was compressed into a mold. The tensile strength of the amalgam specimen was then measured and found to be greater than 10(exp 4) psi (greater than about 69 MPa). Much remains to be done to optimize the properties of amalgams for various applications through suitable choice of starting constituents and modification of the trituration and molding processes. The choice of wire size and composition are expected to be especially important. Perusal of phase diagrams of metal mixtures could give insight that would enable choices of solid and liquid metal constituents. Finally, whereas heretofore, only binary alloys have been considered for amalgams

  3. High-strength mineralized collagen artificial bone

    Science.gov (United States)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  4. Metal recovery from high-grade WEEE

    DEFF Research Database (Denmark)

    Bigum, Marianne; Brogaard, Line Kai-Sørensen; Christensen, Thomas Højlund

    2012-01-01

    Based on available data in the literature the recovery of aluminium, copper, gold, iron, nickel, palladium and silver from high-grade WEEE was modeled by LCA. The pre-treatment of WEEE included manual sorting, shredding, magnetic sorting, Eddy-current sorting, air classification and optical sorting...... and refining of ore. The resource recovery per tonne of high-grade WEEE ranged from 2 g of palladium to 386 kg of iron. Quantified in terms of person-equivalents the recovery of palladium, gold, silver, nickel and copper constituted the major environmental benefit of the recovery of metals from WEEE...... effect compared to the metallurgical treatment. However only 12-26% of silver, gold and palladium are recovered during pre-treatment, which suggest that the reduction of the apparent losses of precious metals as palladium, gold and silver during pre-treatment of WEEE is of environmental importance. Our...

  5. Spina bifida occulta in high grade spondylolisthesis.

    Science.gov (United States)

    Babbi, L; Terzi, S; Bandiera, S; Barbanti Brodano, G

    2014-01-01

    A 14-year-old boy presented with symptomatic high-grade dysplastic type spondylolisthesis, with a presence of spina bifida occulta, not diagnosed by plain radiographs, but confirmed on preoperative CT and MR. Circumferential fusion with partial reduction of L5/S1 was performed. Awareness of the coexistence of spondylolisthesis and spina bifida by an accurate preoperative planning is paramount to avoid iatrogenic damage to neural elements during surgery.

  6. High grade glioma: Imaging combined with pathological grade defines management and predicts prognosis

    International Nuclear Information System (INIS)

    Burnet, Neil G.; Lynch, Andrew G.; Jefferies, Sarah J.; Price, Stephen J.; Jones, Phil H.; Antoun, Nagui M.; Xuereb, John H.; Pohl, Ute

    2007-01-01

    Introduction: There is ambiguity in pathological grading of high grade gliomas within the WHO 2000 classification, especially those with predominant oligodendroglial differentiation. Patients and methods: All adult high grade gliomas treated radically, 1996-2005, were assessed. Cases in which pathology was grade III but radiology suggested glioblastoma (GBM) were classified as 'grade III/IV'; their pathology was reviewed. Results: Data from 245 patients (52 grade III, 18 grade III/IV, 175 GBM) were analysed using a Cox Proportional Hazards model. On pathology review, features suggestive of more aggressive behaviour were found in all 18 grade III/IV tumours. Oligodendroglial components with both necrosis and microvascular proliferation were present in 7. MIB-1 counts for the last 8 were all above 14%, mean 27%. Median survivals were: grade III 34 months, grade III/IV 10 months, GBM 11 months. Survival was not significantly different between grade III/IV and GBM. Patients with grade III/IV tumours had significantly worse outcome than grade III, with a hazard of death 3.7 times higher. Conclusions: The results highlight the current inconsistency in pathological grading of high grade tumours, especially those with oligodendroglial elements. Patients with histological grade III tumours but radiological appearances suggestive of GBM should be managed as glioblastoma

  7. Microcracking and durability of high strength concretes

    International Nuclear Information System (INIS)

    Yssorche, M.P.

    1995-07-01

    Durability of 28 days compressive strength concrete of 20 to 120 MPa has been studied. The ability of concrete to transport aggressive agents has been determined for four properties: the air permeability, the chloride diffusivity, the water absorption and the carbonation. A chloride migration test for high and very high strength concrete (HSC and VHSC) has been built. The relationship between transport properties and the compressive strength after one and 28 days of humid curing has always the same shape: transport decreases when strength increases. However, transport properties often vary in the ordinary concrete field. Beyond, the domain is much more limited. The relationship between transport properties and strength valid for ordinary concrete can not be simply extrapolated for HSC and VHSC. To determine the part of microcracking of HSC and VHSC, concrete behaviour stored in two mediums has been studied: the ones shaming the storing condition of concrete in auto-desiccation, the others reproducing the storing conditions of concrete in desiccation. Auto-desiccation (measuring relative humidity at balance) and desiccation (measuring mass losses) have been showed. Microcracks and shrinkage strains have been measured. It has been showed that auto-desiccation microcracks proving in HSC or VHSC don't question the durability. Microcracks, as for permeability, do not develop between 28 days and one year. On the contrary, desiccation microcracks observed in HSC and VHSC, increase with transport properties between 28 days and 1.5 year. Thus, a bulk concrete is always more durable than a cover concrete. At last, the good influence of increase of curing of 1 to 28 days on the transport of all concretes has been emphasized. (author)

  8. Hydrogen Assisted Cracking of High Strength Alloys

    Science.gov (United States)

    2003-08-01

    equilibrium H content for unstressed exposure of the superalloy in a given H2 pressure ( PH2 ) and temperature (T) environment, coupled with enhancement...CRACKING OF HIGH STRENGTH ALLOYS Richard P. Ganqloff August, 2003 Page 72 of 194 decreasing pH , H2S addition, temperature , and other chemical variables...mechanism for stress corrosion cracking (SCC) and sulfide stress cracking for alloys in aqueous H2S -bearing electrolytes. Electrochemical reactions leading

  9. Dual characteristics of yield and ultimate strength as applied to two grades of beryllium

    International Nuclear Information System (INIS)

    Priddy, T.G.; Benzley, S.E.; Johnson, R.L.

    1977-02-01

    Published yield and ultimate biaxial strength data for two grades of beryllium are correlated with the use of a macroscopic failure model. Cross sections of the resulting surfaces in three-dimensional stress space are drawn to illustrate the expected transition from ductile to brittle fracture for triaxial tension states of stress. The usefulness of these models to the prediction of fracture in ductile materials is discussed. 5 tables, 8 figures, 11 references

  10. High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study.

    Science.gov (United States)

    Gnandt, Ryan J; Smith, Jennifer L; Nguyen-Ta, Kim; McDonald, Lucas; LeClere, Lance E

    2016-02-01

    To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair

  11. Realization of commercial high strength HEPA filters

    International Nuclear Information System (INIS)

    Ruedinger, V.; Ricketts, C.I.; Wilhelm, J.G.

    1989-01-01

    HEPA-filter media though having excellent particle removal efficiencies, remain characterized as rather brittle, fragile and weak materials. As a result, undesired structural damage followed by significant losses in filtration efficiency can easily occur in handling, transport, and even normal operation of filter units. In recent years extensive investigations into the structural limits of HEPA filters in dry air and under extended exposure to high humidity airflow have been carried out. In the course of this work the failure modes and the underlying failure mechanisms were thoroughly studied. On the basis of the information obtained, considerable improvements in the structural strength of HEPA filters could be achieved. As verified by removal efficiency tests, differential pressures up to 56kPa in dry air and 15kPa after extended operation under fog conditions were proven to be sustainable without mechanical damage to the filter medium. In cooperation with three major European filter manufacturers the know-how gained has been transferred into practical application through development of commercially available high-strength filter units. Three new KWU (Siemens-Kraftwerksunion) nuclear power plants in Germany have already been fully equipped with HEPA filters of this improved design. The German licensing authorities are now considering modifications of their requirement specifications to reflect the increased strength of the new filter units

  12. HIGH STRENGTH CONTROL RODS FOR NEUTRONIC REACTORS

    Science.gov (United States)

    Lustman, B.; Losco, E.F.; Cohen, I.

    1961-07-11

    Nuclear reactor control rods comprised of highly compressed and sintered finely divided metal alloy panticles and fine metal oxide panticles substantially uniformly distributed theretbrough are described. The metal alloy consists essentially of silver, indium, cadmium, tin, and aluminum, the amount of each being present in centain percentages by weight. The oxide particles are metal oxides of the metal alloy composition, the amount of oxygen being present in certain percentages by weight and all the oxygen present being substantially in the form of metal oxide. This control rod is characterized by its high strength and resistance to creep at elevated temperatures.

  13. Contemporary management of high-grade gliomas.

    Science.gov (United States)

    Sim, Hao-Wen; Morgan, Erin R; Mason, Warren P

    2018-01-01

    High-grade gliomas, including glioblastoma, are the most common malignant brain tumors in adults. Despite intensive efforts to develop new therapies for these diseases, treatment options remain limited and prognosis is poor. Recently, there have been important advances in our understanding of the molecular basis of glioma, leading to refinements in our diagnostic and management approach. There is new evidence to guide the treatment of elderly patients. A multitude of new agents have been investigated, including targeted therapies, immunotherapeutics and tumor-treating fields. This review summarizes the key findings from this research, and presents a perspective on future opportunities to advance the field.

  14. High-strength chromium--molybdenum rails

    International Nuclear Information System (INIS)

    Smith, Y.E.; Sawhill, J.M. Jr.; Cias, W.W.; Eldis, G.T.

    1976-01-01

    A laboratory study was conducted with the aim of developing an as-rolled rail of over 100 ksi (689 N/mm 2 ) yield strength. A series of compositions providing both pearlitic and bainitic microstructures was evaluated. A fine pearlitic structure was developed in a 0.73 percent C -- 0.83 percent Mn -- 0.16 percent Si -- 0.75 percent Cr -- 0.21 percent Mo steel by simulating the mill cooling rate of 132-lb/yd (65.5-kg/m) rail. Two 100-ton commercial heats were made of this approximate composition and processed into 132-lb/yd (65.5-kg/m) rail. Samples tested in the laboratory ranged from 109 to 125 ksi (750 to 860 N/mm 2 ) in yield strength. The chromium-molybdenum rails also exhibited excellent fracture toughness and fatigue properties. Sections of the rail were joined by both flash-butt welding and thermite welding. The hardness peaks produced in the flash-butt welds could be reduced by applying either a postweld current or an induction heating cycle. The high-strength chromium-molybdenum rails have been in service for over eight months in curved sections of an ore railway that carries over 55 million gross long tons per year. 7 tables, 18 figs

  15. The effect of volume on the tensile strength of several nuclear-grade graphites

    International Nuclear Information System (INIS)

    Strizak, J.P.

    1991-01-01

    This report will present the results of a study on the effects of stress volume on the tensile strength of two nuclear-grade graphites. The materials selected were H-451, an extruded near-isotropic graphite manufactured by Great Lakes Carbon Corporation, and IG-110, a fine-grained isotropic molded graphite manufactured by Toyo Tanso Company, Ltd. The tensile properties of H-451 were examined extensively in the past in order to characterize the variability of strength within billets, between billets, and between lots. But, the variability within a billet was, for the most part, studied only casually. The problem was the strong influence of a limited sampling plan in describing the mean strength and the variability. Therefore, an extensive, statistically sound sampling plan has been devised to fully characterize the spatial variability within a single billet. The effects of stress volume are being reexamined by comparing the strengths of four specimen sizes covering a broad range in stress volume. Two models will be employed for analysis of the stress volume data for the selected graphites. The popular Weibull model has previously been found to grossly overestimate the volume dependence of the strength of H-451 graphite. The model will be reevaluated using the improved statistical distribution of strength expected from the current sampling plan. A new fracture model developed by Burchell and Tucker has potential for determining the effect of stress volume on the tensile strength of graphite. This probabilistic failure criterion combines a microstructural basis with a fracture-mechanics approach to failure. An initial evaluation of H-451 data showed that the model closely predicted the mean tensile strength for the two smaller specimen sizes. 9 refs., 24 figs., 1 tab

  16. Comparison of Thermal Stability of Dry High-strength Concrete and Wet High-strength Concrete

    Directory of Open Access Journals (Sweden)

    Musorina Tatiana

    2018-01-01

    Full Text Available High-strength concrete is a modern material, which occupies it`s own niche on the construction material market. It is applicable in a large-scale high-rise construction, particularly an underground construction is a frequently used solution for a space saving. Usually underground structure is related to a wet usage environment. Though not all properties of the high-strength concrete are investigated to the full extent. Under adverse climatic conditions of the Russian Federation one of the most important properties for constructional materials is a thermal capacity. Therefore, the main purpose of the paper is to compare a thermal capacity of the high-strength concrete in humid conditions and a thermal capacity of the high-strength concrete in dry operational condition. During the study dependency between thermal capacity and design wall thickness and ambient humidity has to be proven with two experiments. As a result the theoretical relation between thermal capacity characteristic – thermal inertia and wall thickness and ambient humidity was confirmed by the experimental data. The thermal capacity of a building is in direct ratio to the construction thickness. It follows from the experiments and calculations that wet high-strength concrete has less thermal stability.

  17. Comparison of Thermal Stability of Dry High-strength Concrete and Wet High-strength Concrete

    Science.gov (United States)

    Musorina, Tatiana; Katcay, Aleksandr; Selezneva, Anna; Kamskov, Victor

    2018-03-01

    High-strength concrete is a modern material, which occupies it`s own niche on the construction material market. It is applicable in a large-scale high-rise construction, particularly an underground construction is a frequently used solution for a space saving. Usually underground structure is related to a wet usage environment. Though not all properties of the high-strength concrete are investigated to the full extent. Under adverse climatic conditions of the Russian Federation one of the most important properties for constructional materials is a thermal capacity. Therefore, the main purpose of the paper is to compare a thermal capacity of the high-strength concrete in humid conditions and a thermal capacity of the high-strength concrete in dry operational condition. During the study dependency between thermal capacity and design wall thickness and ambient humidity has to be proven with two experiments. As a result the theoretical relation between thermal capacity characteristic - thermal inertia and wall thickness and ambient humidity was confirmed by the experimental data. The thermal capacity of a building is in direct ratio to the construction thickness. It follows from the experiments and calculations that wet high-strength concrete has less thermal stability.

  18. Oxford Grading Scale vs manometer for assessment of pelvic floor strength in nulliparous sports students.

    Science.gov (United States)

    Da Roza, T; Mascarenhas, T; Araujo, M; Trindade, V; Jorge, R Natal

    2013-09-01

    To compare pelvic floor muscle strength in nulliparous sports students measured using the modified Oxford Grading Scale and a Peritron manometer; and to compare the manometric measurements between continent and incontinent subjects. Cross-sectional study. All subjects were evaluated twice on the same day; first by vaginal digital examination and subsequently by vaginal pressure using a Peritron manometer. Forty-three nulliparous female sports students [mean age 21 (standard deviation 4) years] from the Sports Faculty of the University of Porto. This study found a significant moderate correlation between the Oxford Grading Scale score and peak pressure on manometry (r=0.646, P=0.002). Mean maximal strength for the entire group was 70.4cmH2O (range 21 to 115cmH2O). Out of 43 subjects, 37% (n=16) demonstrated signs of incontinence. On manometry, no significant differences were found in vaginal resting pressure or peak pressure between the continent and incontinent groups. There was moderate correlation between peak pressure on manometry and the Oxford Grading Scale score. Peritron manometer measurements of pelvic floor muscle contractions showed no significant differences in vaginal resting pressure and peak pressure in continent and incontinent subjects. Copyright © 2012 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  19. Weld Design, Testing, and Assessment Procedures for High Strength Pipelines

    Science.gov (United States)

    2011-12-20

    Long-distance high-strength pipelines are increasingly being constructed for the efficient transportation of energy products. While the high-strength linepipe steels and high productivity welding processes are being applied, the procedures employed f...

  20. Ultrasonic fatigue of a high strength steel

    Science.gov (United States)

    Koster, M.; Wagner, G.; Eifler, D.

    2010-07-01

    At the Institute of Materials Science and Engineering at the University of Kaiserslautern an ultrasonic testing system for the fatigue assessment of metallic materials in the very high cycle fatigue (VHCF) regime was developed. The ultrasonic testing system allows to control the test and to measure detailed fatigue data. The achieved results can be used to describe the cyclic deformation behaviour of wheel steels at ultrasonic frequencies. In load increase tests (LIT), the critical stress amplitude can be determined, which leads to a defined change of process parameters like generator power, dissipated energy and specimen temperature. With SEM investigations it was proved that the change of the process parameters correlates with irreversible changes in the microstructure. It can be shown that the stress amplitude, leading to first irreversible changes in the microstructure, strongly depends on the depth position within the original wheel rim. New and basic results on the fatigue mechanisms of high strength steels in the VHCF-regime can be achieved.

  1. Preventing the embrittling by hydrogen when galvanizing high-grade steel

    Energy Technology Data Exchange (ETDEWEB)

    Paatsch, W.

    1987-09-01

    Galvanic precipitation of a double layer consisting of a dull nickel layer overlaid with a brilliant zinc layer on low-alloyed high-strength steel grades leads to the forming of zinc-nickel alloy layers during the subsequent heat treatment. According to traction tests carried out on high-strength steel grades, as well as to hydrogen permeability tests, this process prevents embrittling by hydrogen which might be caused by galvanic process sequences - and creates a diffusion block at the same time. The alloy layers have an excellent corrosion resistance and temperature stability.

  2. High-grade primary pulmonary leiomyosarcoma

    Directory of Open Access Journals (Sweden)

    Rodrigo Afonso da Silva Sardenberg

    2011-12-01

    Full Text Available Primary sarcomas of the lung are rare and account for 0.5% of all primary lung tumors. There were approximately 300 cases described in the literature as of 2006. All histologic types of sarcoma were described, and the most common intrathoracic types reported were angiosarcoma, leiomyosarcoma, fibrosarcoma, hemangiopericytoma, and rhabdomyosarcoma. The biological behavior of these tumors is not well-known due to their low frequency. Leiomyosarcomas represent one of the most common subtypes encountered in the lungs, and usually occur during the sixth decade, with male predominance. Although the frequency of metastatic disease is not related to tumor size, prognosis was reported to be poorer in high-grade tumors. In comparison with other sarcomas, survival after complete resection of pulmonary leiomyosarcoma was reported as longer. We report on a patient with primary leiomyosarcoma originating from the bronchus with complete resection and long-term follow-up.

  3. Posterior surgery in high-grade spondylolisthesis.

    Science.gov (United States)

    Lengert, R; Charles, Y P; Walter, A; Schuller, S; Godet, J; Steib, J-P

    2014-09-01

    High-grade L5-S1 spondylolisthesis alters sagittal spinopelvic balance, which can cause low back pain and progressive neurologic disorder. The present study assessed spondylolisthesis reduction and maintenance over time with L4-S1 versus L5-S1 fusion using a lever-arm system and posterior fusion combined with lumbosacral graft. Forty patients were operated on for symptomatic high-grade spondylolisthesis, 34 of whom had full pre- and post-operative radiological analysis, with a mean follow-up of 5.4years. There were 9 L5-S1 and 25 L4-S1 instrumentations. Analysis of spinopelvic and slipping parameters and the evolution of segmental lordosis compared results between L5-S1 and L4-S1 instrumentation. Mean Taillard spondylolisthesis index decreased from 64% to 37% (P=0.0001). Overall sagittal spinopelvic balance was not significantly changed. Overall L1-S1 and segmental L4-L5 lordosis were not affected by instrumentation. Mean L5-S1 segmental lordosis increased from 11° to 18°. There was loss of reduction from 19° to 14° with L5-S1 instrumentation, in contrast to maintained reduction with L4-S1 instrumentation (P=0.006). The lever-arm system provided anterior-posterior reduction of spondylolisthesis and corrected slippage. Postoperative change in overall sagittal spinopelvic balance was slight and constant. Posterior L4-S1 fusion provided better long-term control of L5-S1 lordosis reduction than the shorter L5-S1 fusion. Retrospective study of level IV. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Use of Niobium High Strength Steels with 450 MPA Yield Strength for Construction

    Science.gov (United States)

    Silvestre, Leonardo; Langenberg, Peter; Amaral, Thiago; Carboni, Marcelo; Meira, Marcos; Jordão, Alexandre

    This paper presents an actual case of a new industrial building at CBMM's plant in Araxá, Brazil as an example of lean design using microalloyed steels. The structure consists mostly of microalloyed ASTM A572 steel grades 65 and 50 instead of the conventional carbon manganese ASTM A36 steel. The application of grade 65 with more than 450 MPa of yield strength is an innovative solution for this type of construction in South America. A complete welding evaluation performed on the low carbon, niobium microalloyed grade 65 steel showed the welding properties and benefits. Niobium's effect of increasing strength and toughness simultaneously resulted in relevant savings in total steel consumption for the project. The paper also quantifies the expected savings in costs, energy and carbon dioxide emissions.

  5. Denitrification of high strength nitrate waste.

    Science.gov (United States)

    Dhamole, Pradip B; Nair, Rashmi R; D'Souza, Stanislaus F; Lele, S S

    2007-01-01

    The aim of the present work was to study the treatment of high strength nitrate waste (40000 ppm NO(3) i.e., 9032 ppm NO(3)-N) by acclimatizing sludge initially capable of degrading dilute streams (100-200 ppm NO(3)-N). Sludge from an effluent treatment plant of a fertilizer industry was acclimatized for 15 d each at 1694, 3388, 6774 and 9032 ppm NO(3)-N in a 4 L sequencing batch reactor. Complete denitrification of extremely concentrated nitrate waste (9032 ppm NO(3)-N) using acclimatized sludge was achieved in just 6 h. During the acclimatization period, increase in nitrite peak value from zero to 5907 ppm NO(2)-N was observed, as the concentration was increased from 1694 to 9032 ppm NO(3)-N. Kinetic analysis of the nitrate and nitrite profile could reasonably support microbiological explanations for nitrite build up and changes in sludge composition.

  6. Transition from low-grade endometrial stromal sarcoma to high-grade endometrial stromal sarcoma.

    Science.gov (United States)

    Ohta, Yoshiki; Suzuki, Takao; Omatsu, Mutsuko; Hamatani, Shigeharu; Shiokawa, Akira; Kushima, Miki; Ota, Hidekazu

    2010-07-01

    We report on a case of a primary low-grade endometrial stromal sarcoma (ESS) that progressed to a secondary high-grade ESS. In the secondary tumor, the immunohistochemical profile and focal tumor cell proliferation pattern suggested that this tumor was not truly undifferentiated, but possessed features of endometrial stroma. Low-grade ESS of our patient's primary tumor showed p53 protein overexpression, which is unusual in low-grade ESS, and her secondary high-grade ESS showed more prominent p53 immunoreactivity. This indicates that low-grade ESS that shows p53 immunoreactivity might progress to high-grade ESS, and it is considered that such cases of low-grade ESS should pay attention to the prognosis. Immunoreactivity for epidermal growth factor receptor was observed in both tumors, suggesting a relationship between the primary and secondary tumors in our case. Further study requires more immunohistochemical data for cases in which low-grade ESS transitions to high-grade ESS; in particular, data on epidermal growth factor receptor expression are necessary to define new therapeutic strategies for ESS.

  7. Change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence

    Directory of Open Access Journals (Sweden)

    Tetyana Bala

    2015-06-01

    Full Text Available Purpose: determine the degree of change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence. Material and Methods: theoretical analysis and generalization of scientific and methodical literature, pedagogical testing, pedagogical experiment and mathematical statistics methods. Results: parameters of strength and endurance development level are presented with their degree of change under cheerleading exercises influence for 5-6 grades pupils of secondary school. Conclusions: cheerleading exercises usage has positive influence on demonstrated strength and endurance degree of secondary school children by all investigated parameters.

  8. Estimation of Compressive Strength of High Strength Concrete Using Non-Destructive Technique and Concrete Core Strength

    Directory of Open Access Journals (Sweden)

    Minkwan Ju

    2017-12-01

    Full Text Available Estimating the compressive strength of high strength concrete (HSC is an essential investigation for the maintenance of nuclear power plant (NPP structures. This study intends to evaluate the compressive strength of HSC using two approaches: non-destructive tests and concrete core strength. For non-destructive tests, samples of HSC were mixed to a specified design strength of 40, 60 and 100 MPa. Based on a dual regression relation between ultrasonic pulse velocity (UPV and rebound hammer (RH measurements, an estimation expression is developed. In comparison to previously published estimation equations, the equation proposed in this study shows the highest accuracy and the lowest root mean square error (RMSE. For the estimation of compressive strength using concrete core specimens, three different concrete core diameters were examined: 30, 50, and 100 mm. Based on 61 measured compressive strengths of core specimens, a simple strength correction factor is investigated. The compressive strength of a concrete core specimen decreases as the core diameter reduces. Such a relation is associated with the internal damage of concrete cores and the degree of coarse aggregate within the core diameter from the extracting process of the cores. The strength estimation expressions was formulated using the non-destructive technique and the core strength estimation can be updated with further test results and utilized for the maintenance of NPP.

  9. Aluminum/steel wire composite plates exhibit high tensile strength

    Science.gov (United States)

    1966-01-01

    Composite plate of fine steel wires imbedded in an aluminum alloy matrix results in a lightweight material with high tensile strength. Plates have been prepared having the strength of titanium with only 85 percent of its density.

  10. High Performance Graded Index Polymer Optical Fibers

    National Research Council Canada - National Science Library

    Garito, Anthony

    1998-01-01

    ...) plastic optical fibers (POF) and graded index (GI) POFs are reported. A set of criteria and analyses of physical parameters are developed in context to the major issues of POF applications in short-distance communication systems...

  11. Forming of High-strength Steels Using a Hot-melt Dry Lubricant

    DEFF Research Database (Denmark)

    Hörnström, Sven-Erik; Karlsson, Erik; Olsson, Mikael

    2008-01-01

    steel grades and improved surface engineering treatments such as the deposition of low friction CVD and PVD coatings. In the present study the performance of a hot-melt dry lubricant in the forming of hot and cold rolled and hot-dip galvanized high strength steel has been evaluated and compared...

  12. Advanced High Strength Steel in Auto Industry: an Overview

    Directory of Open Access Journals (Sweden)

    N. Baluch

    2014-08-01

    Full Text Available The world’s most common alloy, steel, is the material of choice when it comes to making products as diverse as oil rigs to cars and planes to skyscrapers, simply because of its functionality, adaptability, machine-ability and strength. Newly developed grades of Advanced High Strength Steel (AHSS significantly outperform competing materials for current and future automotive applications. This is a direct result of steel’s performance flexibility, as well as of its many benefits including low cost, weight reduction capability, safety attributes, reduced greenhouse gas emissions and superior recyclability. To improve crash worthiness and fuel economy, the automotive industry is, increasingly, using AHSS. Today, and in the future, automotive manufacturers must reduce the overall weight of their cars. The most cost-efficient way to do this is with AHSS. However, there are several parameters that decide which of the AHSS types to be used; the most important parameters are derived from the geometrical form of the component and the selection of forming and blanking methods. This paper describes the different types of AHSS, highlights their advantages for use in auto metal stampings, and discusses about the new challenges faced by stampers, particularly those serving the automotive industry.

  13. Transition of low-grade to high-grade endometrial stromal sarcoma: a case report.

    Science.gov (United States)

    Kanda, M; Sonoyama, A; Hirano, H; Kizaki, T; Ohara, N

    2013-01-01

    The transition of low-grade endometrial stromal sarcoma (ESS) to high-grade ESS remains a rare clinical event. A patient presented with abdominal pain and abnormal genital bleeding. She underwent a supracervical hysterectomy with bilateral salpingo-oophorectomy, omentectomy, and resection of peritoneal disseminated lesions. Pathological examination revealed low-grade ESS in the uterus and omentum. Immunohistochemical examination showed immunoreactivity for CD10 and Ki-67 (MIB1) in the uterus and omentum. However, estrogen receptor, progesterone receptor, alpha-SMA, desmin, h-caldesmon, and CAM5-2 were negative. P53 immunoreactivity was noted only in the omental lesion. Despite performing six courses of adjuvant chemotherapy, she recurred in the abdomen. She underwent ileostomy and resection of peritoneal disseminated lesions. Pathology showed high-grade ESS in the recurrent lesion of the ileum, which was characterized by severe cytologic atypia, high mitotic index, multifocal necrosis, increased Ki-67 index, and immunoreactivity for p53. Although rare, the transition of low-grade ESS to high-grade ESS may occur and suggests the worsening of the prognosis. Pathological examination and immunohistochemistry are useful for the diagnosis of the transition of low-grade ESS to high-grade ESS.

  14. Grades, Coursework, and Student Characteristics in High School Economics

    Science.gov (United States)

    Rebeck, Ken; Walstad, William B.

    2015-01-01

    The authors use U.S. public and private high school transcripts to analyze grade distribution patterns in economics courses across student and school characteristics, and compare these grades to those earned in other selected high school courses. Results are reported for the 53 percent of 2009 high school graduates who took a basic economics…

  15. Multiparametric Magnetic Resonance Imaging for Discriminating Low-Grade From High-Grade Prostate Cancer

    NARCIS (Netherlands)

    Vos, E.K.; Kobus, T.; Litjens, G.J.S.; Hambrock, T.; Hulsbergen-van de Kaa, C.A.; Barentsz, J.O.; Maas, M.C.; Scheenen, T.W.J.

    2015-01-01

    The aim of this study was to determine and validate the optimal combination of parameters derived from 3-T diffusion-weighted imaging, dynamic contrast-enhanced imaging, and magnetic resonance (MR) spectroscopic imaging for discriminating low-grade from high-grade prostate cancer (PCa).The study was

  16. Development of a high strength high toughness ausferritic steel

    Energy Technology Data Exchange (ETDEWEB)

    Putatunda, Susil K., E-mail: sputa@eng.wayne.edu [Department of Chemical Engineering and Material Science, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202 (United States); Singar, Arjun V. [Department of Chemical Engineering and Material Science, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202 (United States); Tackett, Ronald; Lawes, Gavin [Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201 (United States)

    2009-07-15

    A new ausferritic steel with high strength and exceptionally high fracture toughness has been developed. This steel has been synthesized integrating concepts from Austempered Ductile Cast Iron (ADI) technology. The influence of the austempering temperature on the microstructure and mechanical properties of this steel at room temperature and ambient atmosphere has been examined. The effect of microstructure on the plane strain fracture toughness and on the magnetic, electrical, and thermal properties was also investigated. Compact tension and cylindrical tensile specimens prepared from the low alloy medium carbon steel with high silicon content were initially austenitized at 927 deg. C for 2 h and then subsequently austempered at several temperatures between 260 deg. C (500 F) and 400 deg. C (750 F) to produce different microstructures. The microstructures were characterized by X-ray diffraction, scanning electron microscopy and optical metallography. A combination of exceptionally high yield strength (1336 MPa) and a high fracture of toughness of 116 MPa{radical}m (a value comparable to maraging steel) was obtained in this steel after austempering at 316 deg. C (600 F) for 2 h. Potential applications of this steel include the inexpensive fabrication of armored plates and components requiring high reliability and durability.

  17. Process optimization for advanced high conductivity - high strength materials

    International Nuclear Information System (INIS)

    Pantsyrnyi, V.; Shikov, A.; Nikulin, A.

    1998-09-01

    On the basis of investigations carried out earlier, two types of high strength-high conductivity Cu-Nb wires have been designed and appropriate manufacturing processes have been proposed and experimentally approved. Long length conductors with rectangular cross sections 4 x 6 mm 2 and 2 x 3 mm 2 have been fabricated by the in situ process and by the bundle and deform process, which eliminates the operation of melting, accordingly. Investigation on the microstructure of both types of the fabricated wires has been conducted. Mechanical properties and electrical conductivity parameters have been measured also

  18. Diffusion Profiling via a Histogram Approach Distinguishes Low-grade from High-grade Meningiomas, Can Reflect the Respective Proliferative Potential and Progesterone Receptor Status.

    Science.gov (United States)

    Gihr, Georg Alexander; Horvath-Rizea, Diana; Garnov, Nikita; Kohlhof-Meinecke, Patricia; Ganslandt, Oliver; Henkes, Hans; Meyer, Hans Jonas; Hoffmann, Karl-Titus; Surov, Alexey; Schob, Stefan

    2018-02-01

    Presurgical grading, estimation of growth kinetics, and other prognostic factors are becoming increasingly important for selecting the best therapeutic approach for meningioma patients. Diffusion-weighted imaging (DWI) provides microstructural information and reflects tumor biology. A novel DWI approach, histogram profiling of apparent diffusion coefficient (ADC) volumes, provides more distinct information than conventional DWI. Therefore, our study investigated whether ADC histogram profiling distinguishes low-grade from high-grade lesions and reflects Ki-67 expression and progesterone receptor status. Pretreatment ADC volumes of 37 meningioma patients (28 low-grade, 9 high-grade) were used for histogram profiling. WHO grade, Ki-67 expression, and progesterone receptor status were evaluated. Comparative and correlative statistics investigating the association between histogram profiling and neuropathology were performed. The entire ADC profile (p10, p25, p75, p90, mean, median) was significantly lower in high-grade versus low-grade meningiomas. The lower percentiles, mean, and modus showed significant correlations with Ki-67 expression. Skewness and entropy of the ADC volumes were significantly associated with progesterone receptor status and Ki-67 expression. ROC analysis revealed entropy to be the most accurate parameter distinguishing low-grade from high-grade meningiomas. ADC histogram profiling provides a distinct set of parameters, which help differentiate low-grade versus high-grade meningiomas. Also, histogram metrics correlate significantly with histological surrogates of the respective proliferative potential. More specifically, entropy revealed to be the most promising imaging biomarker for presurgical grading. Both, entropy and skewness were significantly associated with progesterone receptor status and Ki-67 expression and therefore should be investigated further as predictors for prognostically relevant tumor biological features. Since absolute ADC

  19. Terahertz reflectometry imaging for low and high grade gliomas

    Science.gov (United States)

    Ji, Young Bin; Oh, Seung Jae; Kang, Seok-Gu; Heo, Jung; Kim, Sang-Hoon; Choi, Yuna; Song, Seungri; Son, Hye Young; Kim, Se Hoon; Lee, Ji Hyun; Haam, Seung Joo; Huh, Yong Min; Chang, Jong Hee; Joo, Chulmin; Suh, Jin-Suck

    2016-01-01

    Gross total resection (GTR) of glioma is critical for improving the survival rate of glioma patients. One of the greatest challenges for achieving GTR is the difficulty in discriminating low grade tumor or peritumor regions that have an intact blood brain barrier (BBB) from normal brain tissues and delineating glioma margins during surgery. Here we present a highly sensitive, label-free terahertz reflectometry imaging (TRI) that overcomes current key limitations for intraoperative detection of World Health Organization (WHO) grade II (low grade), and grade III and IV (high grade) gliomas. We demonstrate that TRI provides tumor discrimination and delineation of tumor margins in brain tissues with high sensitivity on the basis of Hematoxylin and eosin (H&E) stained image. TRI may help neurosurgeons to remove gliomas completely by providing visualization of tumor margins in WHO grade II, III, and IV gliomas without contrast agents, and hence, improve patient outcomes. PMID:27782153

  20. nanocomposite hydrogels with high gel strength

    Indian Academy of Sciences (India)

    used in many fields such as hygienic products,1 agriculture,2,3 waste water treatment,4,5 drug-delivery systems6– ... commercially synthesized hectorite product was used to prepare NC gels by inverse microemulsion poly- ... 2.4 Gel strength evaluation of the nanocomposite hydrogels. The apparent viscosity was a relative ...

  1. Mechanical behavior of high strength ceramic fibers at high temperatures

    Science.gov (United States)

    Tressler, R. E.; Pysher, D. J.

    1991-01-01

    The mechanical behavior of commercially available and developmental ceramic fibers, both oxide and nonoxide, has been experimentally studied at expected use temperatures. In addition, these properties have been compared to results from the literature. Tensile strengths were measured for three SiC-based and three oxide ceramic fibers for temperatures from 25 C to 1400 C. The SiC-based fibers were stronger but less stiff than the oxide fibers at room temperature and retained more of both strength and stiffness to high temperatures. Extensive creep and creep-rupture experiments have been performed on those fibers from this group which had the best strengths above 1200 C in both single filament tests and tests of fiber bundles. The creep rates for the oxides are on the order of two orders of magnitude faster than the polymer derived nonoxide fibers. The most creep resistant filaments available are single crystal c-axis sapphire filaments. Large diameter CVD fabricated SiC fibers are the most creep and rupture resistant nonoxide polycrystalline fibers tested to date.

  2. Clinical and molecular features of high-grade osteosarcoma

    NARCIS (Netherlands)

    Anninga, Jakob Klaas

    2013-01-01

    It can be concluded from this thesis that high-grade osteosarcoma is at clinical, pathological and molecular level a heterogeneous disease. To treat high-grade osteosarcoma, neo-adjuvant chemotherapy should be combined with radical surgery, irrespective the localization. There are only 4 effective

  3. Strength of precast concrete shear joints reinforced with high-strength wire ropes

    DEFF Research Database (Denmark)

    Joergensen, Henrik B.; Hoang, Linh Cao; Hagsten, Lars German

    2017-01-01

    This paper concerns the in-plane shear strength of connections between precast concrete wall elements reinforced with looped high-strength wire ropes. The looped wire ropes are pre-installed in so-called ‘wire boxes’ which function as shear keys. Although only a small amount of research...... on the shear strength of such connections can be found in the literature, this type of connection is increasingly being used because wire ropes are much more construction-friendly than traditional U-bars. A rigid plastic upper bound model for the shear strength of wall connections reinforced with looped wire...

  4. Development of K-Basin High-Strength Homogeneous Sludge Simulants and Correlations Between Unconfined Compressive Strength and Shear Strength

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo; Baer, Ellen BK; Chun, Jaehun; Yokuda, Satoru T.; Schmidt, Andrew J.; Sande, Susan; Buchmiller, William C.

    2011-02-20

    K-Basin sludge will be stored in the Sludge Transport and Storage Containers (STSCs) at an interim storage location on Central Plateau before being treated and packaged for disposal. During the storage period, sludge in the STSCs may consolidate/agglomerate, potentially resulting in high-shear-strength material. The Sludge Treatment Project (STP) plans to use water jets to retrieve K-Basin sludge after the interim storage. STP has identified shear strength to be a key parameter that should be bounded to verify the operability and performance of sludge retrieval systems. Determining the range of sludge shear strength is important to gain high confidence that a water-jet retrieval system can mobilize stored K-Basin sludge from the STSCs. The shear strength measurements will provide a basis for bounding sludge properties for mobilization and erosion. Thus, it is also important to develop potential simulants to investigate these phenomena. Long-term sludge storage tests conducted by Pacific Northwest National Laboratory (PNNL) show that high-uranium-content K-Basin sludge can self-cement and form a strong sludge with a bulk shear strength of up to 65 kPa. Some of this sludge has 'paste' and 'chunks' with shear strengths of approximately 3-5 kPa and 380-770 kPa, respectively. High-uranium-content sludge samples subjected to hydrothermal testing (e.g., 185 C, 10 hours) have been observed to form agglomerates with a shear strength up to 170 kPa. These high values were estimated by measured unconfined compressive strength (UCS) obtained with a pocket penetrometer. Due to its ease of use, it is anticipated that a pocket penetrometer will be used to acquire additional shear strength data from archived K-Basin sludge samples stored at the PNNL Radiochemical Processing Laboratory (RPL) hot cells. It is uncertain whether the pocket penetrometer provides accurate shear strength measurements of the material. To assess the bounding material strength and

  5. Effect of microstructure on the high temperature strength of nitride

    Indian Academy of Sciences (India)

    Effect of microstructure on the high temperature strength of nitride bonded silicon carbide composite. J Rakshit P K Das. Composites Volume ... The effect of these parameters on room temperature and high temperature strength of the composite up to 1300°C in ambient condition were studied. The high temperature flexural ...

  6. Low velocity impact behaviour of ultra high strength concrete panels

    Indian Academy of Sciences (India)

    parametric studies by varying the volume fraction of steel fibres. Keywords. Ultra high strength concrete; panel; drop weight test; impact analysis;. ABAQUS. 1. Introduction. Ultra high strength concrete is a special type of concrete which is characterized by a low water- binder ratio, high quality pozzolanic material, and without ...

  7. Fatigue strength of repaired cracks in welded connections made of very high strength steels

    NARCIS (Netherlands)

    Akyel, A.

    2017-01-01

    For cyclically loaded structures, fatigue design becomes one of the important design criteria. The state of art shows that with modification of the conventional structural design methodology, the use of very high strength steels may have a positive effect on fatigue strength of welded connections.

  8. Characteristics in Paintability of Advanced High Strength Steels

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ha Sun [POSLAB, POSCO, Gwangyang (Korea, Republic of)

    2007-06-15

    It is expected that advanced high strength steels (AHSS) would be widely used for vehicles with better performance in automotive industries. One of distinctive features of AHSS is the high value of carbon equivalent (Ceq), which results in the different properties in formability, weldability and paintability from those of common grade of steel sheets. There is an exponential relation between Ceq and electric resistance, which seems also to have correlation with the thickness of electric deposition (ED) coat. higher value of Ceq of AHSS lower the thickness of ED coat of AHSS. Some elements of AHSS such as silicon, if it is concentrated on the surface, affect negatively the formation of phosphates. In this case, silicon itself doesn't affect the phosphate, but its oxide does. This phenomenon is shown dramatically in the welding area. Arc welding or laser welding melts the base material. In the process of cooling of AHSS melt, the oxides of Si and Mn are easily concentrated on the surface of boundary between welded and non welded area because Si and Mn cold be oxidized easier than Fe. More oxide on surface results in poor phosphating and ED coating. This is more distinctive in AHSS than in mild steel. General results on paintability of AHSS would be reported, being compared to those of mild steel

  9. Microstructural evolution in high strength materials at high strain rates

    Science.gov (United States)

    Bassim, M. N.; Bolduc, M.; Odeshi, A. G.; Mirfarkraei, S.

    2006-08-01

    High strength materials such as used as armor plate have been investigated in torsion using Split Hopkinson Bars for the purpose of obtaining stress-strain curves and for examining the mechanism of plastic deformation in terms of mechanical instability due to thermal softening at high strain rates. A comparative study of the plastic deformation behavior of RHA steel, Aluminum 5083 H131 alloy and Tungsten A90S alloy under the loading condition at high strain rates is carried out and the effect of strain rate on shear flow stress and stress-strain profiles is presented. Strain rate sensitivities of the materials are evaluated and discussed with respect to mechanical instability and adiabatic shear strain localization.

  10. Biomarker discovery in high grade sarcomas by mass spectrometry imaging

    OpenAIRE

    Lou, S.

    2017-01-01

    This thesis demonstrates a detailed biomarker discovery Mass Spectrometry Imaging workflow for histologically heterogeneous high grade sarcomas. Panels of protein and metabolite signatures were discovered either distinguishing different histological subtypes or stratifying high risk patients with poor survival.

  11. The Graded and Redefined Assessment of Strength, Sensibility, and Prehension Version 2 Provides Interval Measure Properties.

    Science.gov (United States)

    Velstra, Inge-Marie; Fellinghauer, Carolina; Abel, Rainer; Kalsi-Ryan, Sukhvinder; Rupp, Rüdiger; Curt, Armin

    2018-01-16

    The Graded and Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) is a valid, reliable, and responsive outcome measure to evaluate upper limb function in individuals with tetraplegia. GRASSP generates ordinal total scores; therefore, applicability as an interval level measurement requires testing of its measurement properties. This study examined the metric characteristics with Rasch Analysis to derive interval level scales of the respective GRASSP subtests. The GRASSP was recorded within 10 days, and at 1, 3, 6, and 12 months after cervical spinal cord injury (SCI). Rasch analysis was performed for each GRASSP subscale to assess the following metric assumptions: absence of local item dependency (LID), unidimensionality, monotonicity, item and model fit, reliability, and absence of differential item functioning (DIF) for side (left and right) and examination stage. If these assumptions could not be met, adjustments were undertaken to achieve a good fit to the Rasch model. Seventy-seven individuals with cervical SCI were included (n = 154 arms). Stacking the data for the side (left and right) resulted in a total of 614 observations, which were based on the repeated measurements. With minor adjustments, the GRASSP subscales showed good reliability, item fit, and ordered response options. Local item dependencies were found in the strength and sensibility subscales. Redundancies among some measurement items allowed shortening of the subscales without reasonable loss of reliability. Absence of DIF for the examination stage supported robustness of the subscales over time. The modified GRASSP, now Version 2, subtest scores can be applied as interval level measurements, and the reduction of items within subscales allows for shorter assessment times in clinical studies without degrading metric properties.

  12. Evaluation and comparison of transverse and impact strength of different high strength denture base resins.

    Science.gov (United States)

    Gupta, Abhinav; Tewari, R K

    2016-01-01

    The present study was undertaken to evaluate and compare the impact strength and transverse strength of the high-impact denture base materials. A conventional heat polymerized acrylic resin was used as a control. The entire experiment was divided into four main groups with twenty specimens each according to denture base material selected Trevalon, Trevalon Hi, DPI Tuff and Metrocryl Hi. These groups were further subgrouped into the two parameters selected, impact strength and flexural strength with ten specimens each. These specimens were then subjected to transverse bend tests with the help of Lloyds instrument using a three point bend principle. Impact tests were undertaken using an Izod-Charpy digital impact tester. This study was analyzed with one-way analysis of variance using Fisher f-test and Bonferroni t-test. There was a significant improvement in the impact strength of high-impact denture base resins as compared to control (Trevalon). However, in terms of transverse bend tests, only DPI Tuff showed higher transverse strength in comparison to control. Trevalon Hi and Metrocryl Hi showed a decrease in transverse strength. Within the limits of this in vitro study, (1) There is a definite increase in impact strength due to the incorporation of butadiene styrene rubber in this high strength denture base materials as compared to Trevalon used as a control. (2) Further investigations are required to prevent the unduly decrease of transverse strength. (3) It was the limitation of the study that the exact composition of the high-impact resins was not disclosed by the manufacturer that would have helped in better understanding of their behavior.

  13. Evaluation and comparison of transverse and impact strength of different high strength denture base resins

    Directory of Open Access Journals (Sweden)

    Abhinav Gupta

    2016-01-01

    Full Text Available Aim: The present study was undertaken to evaluate and compare the impact strength and transverse strength of the high-impact denture base materials. A conventional heat polymerized acrylic resin was used as a control. Materials and Methods: The entire experiment was divided into four main groups with twenty specimens each according to denture base material selected Trevalon, Trevalon Hi, DPI Tuff and Metrocryl Hi. These groups were further subgrouped into the two parameters selected, impact strength and flexural strength with ten specimens each. These specimens were then subjected to transverse bend tests with the help of Lloyds instrument using a three point bend principle. Impact tests were undertaken using an Izod-Charpy digital impact tester. Results: This study was analyzed with one-way analysis of variance using Fisher f-test and Bonferroni t-test. There was a significant improvement in the impact strength of high-impact denture base resins as compared to control (Trevalon. However, in terms of transverse bend tests, only DPI Tuff showed higher transverse strength in comparison to control. Trevalon Hi and Metrocryl Hi showed a decrease in transverse strength. Conclusions: Within the limits of this in vitro study, (1 There is a definite increase in impact strength due to the incorporation of butadiene styrene rubber in this high strength denture base materials as compared to Trevalon used as a control. (2 Further investigations are required to prevent the unduly decrease of transverse strength. (3 It was the limitation of the study that the exact composition of the high-impact resins was not disclosed by the manufacturer that would have helped in better understanding of their behavior.

  14. Validity of Alternative Fitnessgram Upper Body Tests of Muscular Strength and Endurance among Seventh and Eighth Grade Males and Females

    Science.gov (United States)

    Hobayan, Kalani; Patterson, Debra; Sherman, Clay; Wiersma, Lenny

    2014-01-01

    In a society in which obesity levels have tripled in the past 30 years, the importance of increased fitness levels within the academic setting has become even more critical. The purpose of this study was to investigate the validity of alternative Fitnessgram upper body tests of muscular strength and endurance among seventh and eighth grade males…

  15. Effect of notch location on fatigue crack growth behavior of strength-mismatched high-strength low-alloy steel weldments

    Science.gov (United States)

    Ravi, S.; Balasubramanian, V.; Nasser, S. Nemat

    2004-12-01

    Welding of high-strength low-alloy (HSLA) steels involves the use of low-strength, equal-strength, and high-strength filler materials (electrodes) compared with the parent material, depending on the application of the welded structures and the availability of filler material. In the present investigation, the fatigue crack growth behavior of weld metal (WM) and the heat-affected zone (HAZ) of undermatched (UM), equally matched (EM), and overmatched (OM) joints has been studied. The base material used in this investigation is HSLA-80 steel of weldable grade. Shielded metal arc welding (SMAW) has been used to fabricate the butt joints. A center-cracked tension (CCT) specimen has been used to evaluate the fatigue crack growth behavior of welded joints, utilizing a servo-hydraulic-controlled fatigue-testing machine at constant amplitude loading (R=0). The effect of notch location on the fatigue crack growth behavior of strength mismatched HSLA steel weldments also has been analyzed.

  16. Relationships Between Smelter Grade Alumina Characteristics and Strength Determined by Nanoindentation and Ultrasound-Mediated Particle Breakage

    Science.gov (United States)

    Wijayaratne, Hasini; McIntosh, Grant; Hyland, Margaret; Perander, Linus; Metson, James

    2017-06-01

    The mechanical strength of smelter grade alumina (SGA) is of considerable practical significance for the aluminum reduction process. Attrition of alumina during transportation and handling generates an increased level of fines. This results in generation of dust, poor flow properties, and silo segregation that interfere with alumina feeding systems. These lead to process instabilities which in turn result in current efficiency losses that are costly. Here we are concerned with developing a fundamental understanding of SGA strength in terms of its microstructure. Nanoindentation and ultrasound-mediated particle breakage tests have been conducted to study the strength. Strength of SGA samples both industry calcined and laboratory prepared, decrease with increasing α-alumina (corundum) content contrary to expectation. The reducing strength of alumina with increasing degree of calcination is attributed to the development of a macroporous and abrasion-prone microstructure resulting from the `pseudomorphic' transformation of precursor gibbsite during the calcination process.

  17. Stress corrosion cracking of several high strength ferrous and nickel alloys

    Science.gov (United States)

    Nelson, E. E.

    1971-01-01

    The stress corrosion cracking resistance of several high strength ferrous and nickel base alloys has been determined in a sodium chloride solution. Results indicate that under these test conditions Multiphase MP35N, Unitemp L605, Inconel 718, Carpenter 20Cb and 20Cb-3 are highly resistant to stress corrosion cracking. AISI 410 and 431 stainless steels, 18 Ni maraging steel (250 grade) and AISI 4130 steel are susceptible to stress corrosion cracking under some conditions.

  18. A calculation method of cracking moment for the high strength ...

    Indian Academy of Sciences (India)

    Department of Civil Engineering, Karadeniz Technical University, Trabzon,. 61080, Turkey ... 2. Theoretical study. In this study, it is assumed that angles between axes with failure lines on faces of a high strength ... To calculate concrete stress in a cross section of high strength concrete beams, failure strain is calculated ...

  19. Low velocity impact behaviour of ultra high strength concrete panels

    Indian Academy of Sciences (India)

    Keywords. Ultra high strength concrete; panel; drop weight test; impact analysis; ABAQUS. Abstract. This paper presents the results of an investigation carried out on Ultra High Strength Concrete (UHSC) panels subjected to low velocity projectile impact to assess impact resistance. UHSC panel of size 350 × 350 mm and ...

  20. Braze alloy process and strength characterization studies for 18 nickel grade 200 maraging steel with application to wind tunnel models

    Science.gov (United States)

    Bradshaw, James F.; Sandefur, Paul G., Jr.; Young, Clarence P., Jr.

    1991-01-01

    A comprehensive study of braze alloy selection process and strength characterization with application to wind tunnel models is presented. The applications for this study include the installation of stainless steel pressure tubing in model airfoil sections make of 18 Ni 200 grade maraging steel and the joining of wing structural components by brazing. Acceptable braze alloys for these applications are identified along with process, thermal braze cycle data, and thermal management procedures. Shear specimens are used to evaluate comparative shear strength properties for the various alloys at both room and cryogenic (-300 F) temperatures and include the effects of electroless nickel plating. Nickel plating was found to significantly enhance both the wetability and strength properties for the various braze alloys studied. The data are provided for use in selecting braze alloys for use with 18 Ni grade 200 steel in the design of wind tunnel models to be tested in an ambient or cryogenic environment.

  1. The assessment of bond strength between heat damaged concrete and high strength fibre reinforced concrete

    Science.gov (United States)

    Zahid, M. Z. A. Mohd; Muhamad, K.

    2017-09-01

    The aim of this study is to assess the bond strength between heat damaged concrete and high strength fibre reinforced concrete (HPFRC). Firstly, this paper presents the various steps taken to prepare the HPFRC with self-compacting property. The minimum targeted slump flow is 600 mm and minimum targeted compressive strength is 80 MPa. The key mix variables considered are such as type of superplasticizer, water cement ratio and silica fume content. Then, the bond strength between the heat damaged concrete with HPFRC was examined. The experimental parameters are heating temperature, surface treatment technique and curing method and the results show that, all experimental parameters are significantly affected the bond strength between heat damaged concrete and HPFRC.

  2. Correlation between compressive strength and ultrasonic pulse velocity of high strength concrete incorporating chopped basalt fibre

    Science.gov (United States)

    Shafiq, Nasir; Fadhilnuruddin, Muhd; Elshekh, Ali Elheber Ahmed; Fathi, Ahmed

    2015-07-01

    Ultrasonic pulse velocity (UPV), is considered as the most important test for non-destructive techniques that are used to evaluate the mechanical characteristics of high strength concrete (HSC). The relationship between the compressive strength of HSC containing chopped basalt fibre stands (CBSF) and UPV was investigated. The concrete specimens were prepared using a different ratio of CBSF as internal strengthening materials. The compressive strength measurements were conducted at the sample ages of 3, 7, 28, 56 and 90 days; whilst, the ultrasonic pulse velocity was measured at 28 days. The result of HSC's compressive strength with the chopped basalt fibre did not show any improvement; instead, it was decreased. The UPV of the chopped basalt fibre reinforced concrete has been found to be less than that of the control mix for each addition ratio of the basalt fibre. A relationship plot is gained between the cube compressive strength for HSC and UPV with various amounts of chopped basalt fibres.

  3. Development of LTCC Materials with High Mechanical Strength

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Shinya; Nishiura, Sousuke; Terashi, Yoshitake; Furuse, Tatsuji, E-mail: Shinya.kawai.ke@kyocera.jp [R and D Center Kagoshima, Kyocera Corporation (Japan)

    2011-10-29

    We have developed LTCC materials suitable for substrates of RF modules used in mobile phone. LTCC can provide excellent solutions to requirements of RF modules, such as down-sizing, embedded elements and high performance. It is also important that LTCC material has high mechanical strength to reduce risk of fracture by mechanical impact. We have established a method of material design for high mechanical strength. There are two successive steps in the concept to achieve high mechanical strength. The first step is to improve mechanical strength by increasing the Young's modulus, and the second step is either further improvement through the Young's modulus or enhancement of the fracture energy. The developed material, so called high-strength LTCC, thus possesses mechanical strength of 400MPa, which is twice as strong as conventional material whose mechanical strength is approximately 200MPa in typical. As a result, high-strength LTCC shows an excellent mechanical reliability, against the drop impact test for example. The paper presents material design and properties of LTCC materials.

  4. Development of LTCC Materials with High Mechanical Strength

    International Nuclear Information System (INIS)

    Kawai, Shinya; Nishiura, Sousuke; Terashi, Yoshitake; Furuse, Tatsuji

    2011-01-01

    We have developed LTCC materials suitable for substrates of RF modules used in mobile phone. LTCC can provide excellent solutions to requirements of RF modules, such as down-sizing, embedded elements and high performance. It is also important that LTCC material has high mechanical strength to reduce risk of fracture by mechanical impact. We have established a method of material design for high mechanical strength. There are two successive steps in the concept to achieve high mechanical strength. The first step is to improve mechanical strength by increasing the Young's modulus, and the second step is either further improvement through the Young's modulus or enhancement of the fracture energy. The developed material, so called high-strength LTCC, thus possesses mechanical strength of 400MPa, which is twice as strong as conventional material whose mechanical strength is approximately 200MPa in typical. As a result, high-strength LTCC shows an excellent mechanical reliability, against the drop impact test for example. The paper presents material design and properties of LTCC materials.

  5. On the performance of circular concrete-filled high strength steel columns under axial loading

    Directory of Open Access Journals (Sweden)

    Mohamed Mahmoud El-Heweity

    2012-06-01

    Full Text Available This work presents a numerical study to investigate the performance of circular high-strength steel tubes filled with concrete (CFT under monotonic axial loading. A model is developed to implement the material constitutive relationships and non-linearity. Calibration against previous experimental data shows good agreement. A parametric study is then conducted using the model and compared with codes provisions. Strength and ductility of confined concrete are of primary concern. Variables considered are yield stress of steel tube and column diameter. The assessment of column performance is based on axial load carrying capacities and enhancements of both strength and ductility due to confinement. Two parameters namely strength enhancement factor (Kf and ductility index (μ are clearly defined and introduced for assessment. Results indicate that both concrete strength and ductility of CFT columns are enhanced but to different extents. The ductile behaviors are significantly evident. The increase in yield stress of steel tube has a minimal effect on concrete strength but pronounced effect on concrete ductility. However, reduction in ductility is associated with using high-tensile steel of Grade 70. The overall findings indicate that the use of high-strength tube in CFT columns is not promising. This finding may seriously be considered in seismic design.

  6. Study on the strength characteristics of High strength concrete with Micro steel fibers

    Science.gov (United States)

    Gowdham, K.; Sumathi, A.; Saravana Raja Mohan, K.

    2017-07-01

    The study of High Strength Concrete (HSC) has become interesting as concrete structures grow taller and larger. The usage of HSC in structures has been increased worldwide and has begun to make an impact in India. Ordinary cementitious materials are weak under tensile loads and fiber reinforced cementitious composites (FRCCs) have been developed to improve this weak point. High Strength concrete containing Alccofine as mineral admixture and reinforced with micro steel fibers were cast and tested to study the mechanical properties. The concrete were designed to have compressive strength of 60 MPa. Mixtures containing 0% and 10% replacement of cement by Alccofine and with 1%, 2% and 3% of micro steel fibers by weight of concrete were prepared. Mixtures incorporating Alccofine with fibers developed marginal increase in strength properties at all curing days when compared to control concrete.

  7. 40 CFR 246.200 - High-grade paper recovery.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-grade paper recovery. 246.200 Section 246.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES SOURCE... paper recovery. ...

  8. Cognitive impairments in patients with low grade gliomas and high grade gliomas

    Directory of Open Access Journals (Sweden)

    Eliane C. Miotto

    2011-08-01

    Full Text Available OBJECTIVE: The relationship between brain tumors and cognitive deficits is well established in the literature. However, studies investigating the cognitive status in low and high-grade gliomas patients are scarce, particularly in patients with average or lower educational level. This study aimed at investigating the cognitive functioning in a sample of patients with low and high-grade gliomas before surgical intervention. METHOD: The low-grade (G1, n=19 and high-grade glioma (G2, n=8 patients underwent a detailed neuropsychological assessment of memory, executive functions, visuo-perceptive and visuo-spatial abilities, intellectual level and language. RESULTS: There was a significant impairment on verbal and visual episodic memory, executive functions including mental flexibility, nominal and categorical verbal fluency and speed of information processing in G2. G1 showed only specific deficits on verbal and visual memory recall, mental flexibility and processing speed. CONCLUSION: These findings demonstrated different levels of impairments in the executive and memory domains in patients with low and high grade gliomas.

  9. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    International Nuclear Information System (INIS)

    Han, K.; Embury, J.D.

    1998-01-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications

  10. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    Energy Technology Data Exchange (ETDEWEB)

    Han, K.; Embury, J.D.

    1998-10-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications.

  11. The possibility of using high strength reinforced concrete

    International Nuclear Information System (INIS)

    Miura, Nobuaki

    1991-01-01

    There is recently much research about and developments in reinforced concrete using high strength concrete and reinforcement. As a result, some high-rise buildings and nuclear buildings have been constructed with such concrete. Reinforced concrete will be stronger in the future, but there is a limit to its strength defined by the character of the materials and also by the character of the reinforced concrete members made of the concrete and reinforcement. This report describes the merits and demerits of using high strength reinforced concrete. (author)

  12. Strength and agility skills of grade 1-learners: North-West child study ...

    African Journals Online (AJOL)

    Proficiency, second edition (BOT-2) was used to evaluate the children's strength and agility skills. The results showed meaningful gender differences with respect to the strength skills of the learners, since boys performed better in the standing long ...

  13. Fatigue strength of truss girders made of very high strength steel

    NARCIS (Netherlands)

    Pijpers, R.J.M.; Kolstein, M.H.

    2010-01-01

    An effective application of Very High Strength Steel (VHSS) in civil engineering structures is expected in stiff, truss like structures, typically made of Circular Hollow Sections (CHS). Use of castings in combination with CHS could be promising for the design of highly fatigue resistant joints.

  14. Resistance Spot Welding of Advanced High Strength Steels

    NARCIS (Netherlands)

    Den Uijl, N.J.

    2015-01-01

    The introduction of advanced high strengths steels enabled automotive manufacturers to simultaneously reduce weight and increase safety of vehicles. However issues were reported concerning the weldability of these steels. These issues concerned both the manufacturability as well as the performance

  15. Investigation of high-strength bolt-tightening verification techniques.

    Science.gov (United States)

    2016-03-01

    The current means and methods of verifying that high-strength bolts have been properly tightened are very laborious and time : consuming. In some cases, the techniques require special equipment and, in other cases, the verification itself may be some...

  16. Reliability of Grading High School Work in English

    OpenAIRE

    Hunter M. Brimi

    2011-01-01

    This research replicates the work of Starch and Elliot (1912) by examining the reliability of the grading by English teachers in a single school district. Ninety high school teachers graded the same student paper following professional development sessions in which they were trained to use NWREL's - 6+1 Traits of Writing.- These participants had been instructed to construct a 100-point rubric, assigning point values to each trait (though not all complied with this request). To evaluate the ...

  17. High grade leiomyosarcoma of the testes

    Directory of Open Access Journals (Sweden)

    Girish D. Bakhshi

    2011-11-01

    Full Text Available Testicular leiomyosarcoma is a rare tumor. It may arise secondarily following exposure to radiotherapy, chronic inflammation, or usage of high dose anabolic steroids. However, in absence of risk factors, it is rarely seen. Only 15 cases of Primary Intra testicular leiomyosarcoma have been reported in world literature. We present a case of testicular tumor in an elderly male. Preoperative work up showed raised Lactate Dehydrogenase (LDH levels. He underwent high orchidectomy. Histopathology and immunohistochemistry confirmed it to be a primary intra testicular leiomyosarcoma. A brief case report with review of literature is presented.

  18. Investigation of ultra violet (UV) resistance for high strength fibers

    Science.gov (United States)

    Said, M. A.; Dingwall, Brenda; Gupta, A.; Seyam, A. M.; Mock, G.; Theyson, T.

    Ultra long duration balloons (ULDB), currently under development by the National Aeronautics and Space Administration (NASA), requires the use of high strength fibers in the selected super-pressure pumpkin design. The pumpkin shape balloon concept allows clear separation of the load transferring functions of the major structural elements of the pneumatic envelope, the tendons and the film. Essentially, the film provides the gas barrier and transfers only local pressure load to the tendons. The tendons, in the mean time, provide the global pressure containing strength. In that manner, the strength requirement for the film only depends on local parameters. The tendon is made of p-phenylene-2,6-benzobisoxazole (PBO) fibers, which is selected due to its high strength to weight ratio when compared to other high performance, commercially available, fibers. High strength fibers, however, are known to degrade upon exposure to light, particularly at short wavelengths. This paper reports the results of an investigation of the resistance of four commercial high strength fibers to ultra violet (UV) exposure. The results indicate that exposing high strength fibers in continuous yarn form to UV led to serious loss in strength of the fibers except for Spectra® fibers. The adverse changes in mechanical behavior occurred over short duration of exposure compared to the 100 day duration targeted for these missions. UV blocking finishes to improve the UV resistance of these fibers are being investigated. The application of these specially formulated coatings is expected to lead to significant improvement of the UV resistance of these high performance fibers. In this publication, we report on the mechanical behavior of the fibers pre- and post-exposure to UV, but without application of the blocking finishes.

  19. High-grade fuels and biomass farming

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, B.G.

    1980-11-14

    This article analyzes distorted views that Weisz and Marshall have presented on the energetics and economics of ethanol production via biomass fermentation. Their conclusion, that with current technology ethanol production represents a net consumption of fuel, results from use of an unrealistically high processing energy and neglect of energy credit for the distillers' dry grains. Other fallacies were mentioned: failure to use insights available through the second law of thermodynamics; inconsistency of comparing cost of net alcohol fuel production with the market price of other fuels. It was concluded that if allowed to stand unchallenged, they could do serious damage to future research and development. (DP)

  20. Reliability of Grading High School Work in English

    Directory of Open Access Journals (Sweden)

    Hunter M. Brimi

    2011-11-01

    Full Text Available This research replicates the work of Starch and Elliot (1912 by examining the reliability of the grading by English teachers in a single school district. Ninety high school teachers graded the same student paper following professional development sessions in which they were trained to use NWREL's - 6+1 Traits of Writing.- These participants had been instructed to construct a 100-point rubric, assigning point values to each trait (though not all complied with this request. To evaluate the reliability in grading, data were analyzed for teachers reporting scores on a 100-point scale. Of the 73 participants who graded on a 100-point scale, the scores ranged from 50 to 96. Analysis suggests that many of these teachers are proficient at assessing student writing, many are unaware of or simply resistant to research suggestions for writing assessment, and many show signs of being - assessment illiterate- (Stiggins, 1995.

  1. High grade angiosarcoma arising in fibroadenoma

    Science.gov (United States)

    2011-01-01

    Primary angiosarcoma of the breast is a rare tumour that account for fewer than 0.05% of all malignant mammary tumours. Angiosarcoma may have an perfidious clinical onset. Radiologic findings are often nonspecific and may appear completely normal in one-third of cases with primary angiosarcoma. The prognosis is usually poor because of the high rates of local recurrence and early development of metastases. Aggressive surgical resection is the mainstay of treatment. The role of adjuvant therapy has not yet been well established. Here we present a case of a 53 year old, postmenopausal women with primary angiosarcoma arising in fibroadenoma. To our knowledge, this is the first case described in the literature to date. PMID:22185665

  2. Recent Progress in High Strength Low Carbon Steels

    OpenAIRE

    Zrník, J.; Mamuzić, I.; Dobatkin, S. V.

    2006-01-01

    Advanced High Strength (AHS) steels, among them especially Dual Phase (DP) steels, Transformation Induced Plasticity (TRIP) steels, Complex Phase (CP) steels, Partially Martensite (PM) steels, feature promising results in the field. Their extraordinary mechanical properties can be tailored and adjusted by alloying and processing. The introduction of steels with a microstructure consisting at least of two different components has led to the enlargement of the strength level without a deteriora...

  3. High-strength cellular ceramic composites with 3D microarchitecture

    OpenAIRE

    Bauer, Jens; Hengsbach, Stefan; Tesari, Iwiza; Schwaiger, Ruth; Kraft, Oliver

    2014-01-01

    It has been a long-standing effort to create materials with low density but high strength. Technical foams are very light, but compared with bulk materials, their strength is quite low because of their random structure. Natural lightweight materials, such as bone, are cellular solids with optimized architecture. They are structured hierarchically and actually consist of nanometer-size building blocks, providing a benefit from mechanical size effects. In this paper, we demonstrate that materia...

  4. Compressive mechanical of high strength concrete (HSC) after different high temperature history

    Science.gov (United States)

    Zhao, Dongfu; Liu, Yuchen; Gao, Haijing; Han, Xiao

    2017-08-01

    The compression strength test of high strength concrete under different high-temperature conditions was carried out by universal testing machine. The friction surface of the pressure bearing surface of the specimen was composed of three layers of plastic film and glycerol. The high temperature working conditions were the combination of different heating temperature and different constant temperature time. The characteristics of failure modes and the developments of cracks were observed; the residual compressive strength and stress-strain curves were measured; the effect of different temperature and heating time on the strength and deformation of high strength concrete under uniaxial compression were analyzed; the failure criterion formula of the high strength concrete after high temperature under uniaxial compression was established. The formula of the residual compressive strength of high strength concrete under the influence of heating temperature and constant temperature time was put forward. The relationship between the residual elastic modulus and the peak strain and residual compressive strength of high strength concrete and different high temperature conditions is established. The quantitative relationship that the residual compressive strength decreases the residual elastic modulus decreases and the peak strain increases with the increase of heating temperature and the constant temperature time was given, which provides a reference for the detection and evaluation of high strength concrete structures after fire.

  5. Effect of Curing Temperature Histories on the Compressive Strength Development of High-Strength Concrete

    Directory of Open Access Journals (Sweden)

    Keun-Hyeok Yang

    2015-01-01

    Full Text Available This study examined the relative strength-maturity relationship of high-strength concrete (HSC specifically developed for nuclear facility structures while considering the economic efficiency and durability of the concrete. Two types of mixture proportions with water-to-binder ratios of 0.4 and 0.28 were tested under different temperature histories including (1 isothermal curing conditions of 5°C, 20°C, and 40°C and (2 terraced temperature histories of 20°C for an initial age of individual 1, 3, or 7 days and a constant temperature of 5°C for the subsequent ages. On the basis of the test results, the traditional maturity function of an equivalent age was modified to consider the offset maturity and the insignificance of subsequent curing temperature after an age of 3 days on later strength of concrete. To determine the key parameters in the maturity function, the setting behavior, apparent activation energy, and rate constant of the prepared mixtures were also measured. This study reveals that the compressive strength development of HSC cured at the reference temperature for an early age of 3 days is insignificantly affected by the subsequent curing temperature histories. The proposed maturity approach with the modified equivalent age accurately predicts the strength development of HSC.

  6. Cervical range of motion, cervical and shoulder strength in senior versus age-grade Rugby Union International front-row forwards.

    Science.gov (United States)

    Davies, Mark; Moore, Isabel S; Moran, Patrick; Mathema, Prabhat; Ranson, Craig A

    2016-05-01

    To provide normative values for cervical range of motion (CROM), isometric cervical and shoulder strength for; International Senior professional, and International Age-grade Rugby Union front-row forwards. Cross-sectional population study. All international level front-row players within a Rugby Union Tier 1 Nation. Nineteen Senior and 21 Age-grade front-row forwards underwent CROM, cervical and shoulder strength testing. CROM was measured using the CROM device and the Gatherer System was used to measure multi-directional isometric cervical and shoulder strength. The Age-grade players had significantly lower; cervical strength (26-57% deficits), cervical flexion to extension strength ratios (0.5 vs. 0.6), and shoulder strength (2-36% deficits) than the Senior players. However, there were no differences between front-row positions within each age group. Additionally, there were no differences between age groups or front-row positions in the CROM measurements. Senior Rugby Union front-row forwards have greater cervical and shoulder strength than Age-grade players, with the biggest differences being in cervical strength, highlighting the need for age specific normative values. Importantly, Age-grade players should be evaluated to ensure they have developed sufficient cervical strength prior to entering professional level Rugby Union. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Successful Nonoperative Management of High-Grade Blunt Renal Injuries.

    Science.gov (United States)

    May, Allison M; Darwish, Oussama; Dang, Brian; Monda, John J; Adsul, Prajakta; Syed, Johar; Siddiqui, Sameer A

    2016-01-01

    Current management of high-grade blunt renal trauma favors a nonoperative approach when possible. We performed a retrospective study of high grade blunt renal injuries at our level I trauma center to determine the indications and success of nonoperative management (NOM). 47 patients with blunt grade IV or V injuries were identified between October 2004 and December 2013. Immediate operative patients (IO) were compared to nonoperatively managed (NOM). Of the 47 patients, 3 (6.4%) were IO and 44 (95.6%) NOM. IO patients had a higher heart rate on admission, 133 versus 100 in NOM ( P = 0.01). IO patients had a higher rate of injury to the renal vein or artery (100%) compared to NOM group (18%) ( P = 0.01). NOM failed in 3 of 44 patients (6.8%). Two required nonemergent nephrectomy and one required emergent exploration resulting in nephrectomy. Six NOM patients had kidney-related complications (13.6%). The renal salvage rate for the entire cohort was 87.2% and 93.2% for NOM. Nonoperative management for hemodynamically stable patients with high-grade blunt renal trauma is safe with a low risk of complications. Management decisions should consider hemodynamic status and visualization of active renal bleeding as well as injury grade in determining operative management.

  8. Fatigue Life of High-Strength Steel Offshore Tubular Joints

    DEFF Research Database (Denmark)

    Petersen, Rasmus Ingomar; Agerskov, Henning; Lopez Martinez, Luis

    1996-01-01

    In the present investigation, the fatigue life of tubular joints in offshore steel structures is studied. Two test series on full-scale tubular joints have been carried through. One series was on joints in conventional offshore structural steel, and the other series was on joints in high......-strength steel with a yield stress of 820-830 MPa and with high weldability and toughness properties. The test specimens of both series had the same geometry. The present report concentrates on the results obtained in the investigation on the high-strength steel tubular joints.The test specimens were fabricated...... amplitude fatigue test results showed shorter fatigue lives in variable amplitude loading than should be expected from the linear fatigue damage accumulation formula. Furthermore, the fatigue tests on high-strength steel tubular joints showed slightly longer fatigue lives than those obtained...

  9. Technical Developments and Trends of Earthquake Resisting High-Strength Reinforcing Steel Bars

    International Nuclear Information System (INIS)

    Hwang, Byoungchul; Shim, Jae-Hyeok; Lee, Myoung-Gyu; Lee, Joonho; Jung, Jun-Ho; Kim, Bo-Sung; Won, Sung-Bin

    2016-01-01

    Since reconstruction of old town in Korea requires high-rise and seismic design construction, many attentions have been paid to high strength seismic reinforced steel bar. In the present paper, technical developments and trends are summarized for developing next-generation seismic reinforced steel bar of grade 700 MPa. Steelmaking process requires high energy efficiency and refining ability. Effects of alloying elements are explained, and alloy design based on computational thermodynamics is introduced. On the other hand, it is considered that grain size refinement by the controlled rolling and low temperature transformation structures formed by the accelerated cooling are effective to obtain acceptable mechanical properties with high strength. Finite element simulation analysis is also useful to understand plastic deformation by rolling, internal and external heat transfer, and corresponding phase transformation of austenite phase to various low-temperature transformation structures.

  10. Technical Developments and Trends of Earthquake Resisting High-Strength Reinforcing Steel Bars

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Byoungchul [Seoul National University of Science and Technology, Seoul (Korea, Republic of); Shim, Jae-Hyeok [Korea Institute of Science and Technology, Seoul (Korea, Republic of); Lee, Myoung-Gyu; Lee, Joonho [Korea University, Seoul (Korea, Republic of); Jung, Jun-Ho [Hyundai Steel, Incheon (Korea, Republic of); Kim, Bo-Sung [Daehan Steel, Busan (Korea, Republic of); Won, Sung-Bin [Dongkuk Steel, Kyungju (Korea, Republic of)

    2016-12-15

    Since reconstruction of old town in Korea requires high-rise and seismic design construction, many attentions have been paid to high strength seismic reinforced steel bar. In the present paper, technical developments and trends are summarized for developing next-generation seismic reinforced steel bar of grade 700 MPa. Steelmaking process requires high energy efficiency and refining ability. Effects of alloying elements are explained, and alloy design based on computational thermodynamics is introduced. On the other hand, it is considered that grain size refinement by the controlled rolling and low temperature transformation structures formed by the accelerated cooling are effective to obtain acceptable mechanical properties with high strength. Finite element simulation analysis is also useful to understand plastic deformation by rolling, internal and external heat transfer, and corresponding phase transformation of austenite phase to various low-temperature transformation structures.

  11. Industrial based volume manufacturing of lightweight aluminium alloy panel components with high-strength and complex-shape for car body and chassis structures

    Science.gov (United States)

    Anyasodor, Gerald; Koroschetz, Christian

    2017-09-01

    To achieve the high volume manufacture of lightweight passenger cars at economic cost as required in the automotive industry, low density materials and new process route will be needed. While high strength aluminium alloy grades: AA7075 and AA6082 may provide the alternative material solution, hot stamping process used for high-strength and ultrahigh strength steels such as boron steel 22mnb5 can enable the volume manufacture of panel components with high-strength and complex-shape for car body and chassis structures. These aluminium alloy grades can be used to manufacture panel components with possible yield strengths ≥ 500 MPa. Due to the differences in material behaviors, hot stamping process of 22mnb5 cannot be directly applied to high strength aluminium alloy grades. Despite recorded successes in laboratories, researches and niche hot forming processes of high strength aluminium alloy grades, not much have been achieved for adequate and efficient volume manufacturing system applicable in the automotive industry. Due to lack of such system and based on expert knowledge in hot stamping production-line, AP&T presents in this paper a hot stamping processing route for high strength aluminium alloys been suitable for production-line development and volume manufacturing.

  12. Behaviour of high-strength concrete incorporating ground ...

    African Journals Online (AJOL)

    Behaviour of high-strength concrete incorporating ground granulated blast furnace slag at high-temperature. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, ...

  13. Optimal welding technology of high strength steel S690QL

    Directory of Open Access Journals (Sweden)

    Dusan Arsic

    2015-02-01

    Full Text Available In this paper is presented the detailed procedure for defining the optimal technology for welding the structures made of the high strength steel S690QL. That steel belongs into a group of steels with exceptional mechanical properties. The most prominent properties are the high tensile strength and impact toughness, at room and at elevated temperatures, as well. However, this steel has a negative characteristic - proneness to appearance of cold cracks.  That impedes welding and makes as an imperative to study different aspects of this steel's properties as well as those of eventual filler metal. Selection and defining of the optimal welding technology of this high strength steel is done for the purpose of preserving the favorable mechanical properties once the welded joint is realized; properties of the welded metal and the melting zone, as well as in the heat affected zone, which is the most critical zone of the welded joint.

  14. Additively manufactured hierarchical stainless steels with high strength and ductility

    Science.gov (United States)

    Wang, Y. Morris; Voisin, Thomas; McKeown, Joseph T.; Ye, Jianchao; Calta, Nicholas P.; Li, Zan; Zeng, Zhi; Zhang, Yin; Chen, Wen; Roehling, Tien Tran; Ott, Ryan T.; Santala, Melissa K.; Depond, Philip J.; Matthews, Manyalibo J.; Hamza, Alex V.; Zhu, Ting

    2018-01-01

    Many traditional approaches for strengthening steels typically come at the expense of useful ductility, a dilemma known as strength-ductility trade-off. New metallurgical processing might offer the possibility of overcoming this. Here we report that austenitic 316L stainless steels additively manufactured via a laser powder-bed-fusion technique exhibit a combination of yield strength and tensile ductility that surpasses that of conventional 316L steels. High strength is attributed to solidification-enabled cellular structures, low-angle grain boundaries, and dislocations formed during manufacturing, while high uniform elongation correlates to a steady and progressive work-hardening mechanism regulated by a hierarchically heterogeneous microstructure, with length scales spanning nearly six orders of magnitude. In addition, solute segregation along cellular walls and low-angle grain boundaries can enhance dislocation pinning and promote twinning. This work demonstrates the potential of additive manufacturing to create alloys with unique microstructures and high performance for structural applications.

  15. The effect of varied mix proportion and water-cement ratio on the compressive strength of medium grade concretepoduced from Bama gravel

    Directory of Open Access Journals (Sweden)

    L. O. Omundi

    2001-10-01

    Full Text Available Concrete cubes produced from Bama gravel (Category B using varied mix proportions and water-cement ratios were subjected to compressive strength and density tests at the curing ages 7, 14 and 28 days. The results indicated that the strength of 28.00Nmm-2 was recorded from the mix proportion of 1:1/2:4 and water-cement ratio of 0.55, which corresponds to a density of 2495 kgm-3. A careful inspection of the results obtained generally shows that the strenfths are inversely proportional to the fine aggregate content and water-cement ratios. It is recommended that great care should be taken while mixing the aggregate proportions of the Bama gravel in order to obtain high quality medium grade concrete for construction purposes.

  16. [How to biopsy only men with high grade prostate cancer].

    Science.gov (United States)

    Benecchi, Luigi; Bocchi, Francesca; Martinotti, Mario; Perucchini, Laura; Quarta, Matteo; Russo, Fabrizio; Tonghini, Mario; Del Boca, Carlo

    2013-04-24

    Fuzzy logic and Artificial Neural Networks (ANN) are complementary technologies that together generate neuro-fuzzy system. The aim of our study is to compare 2 models for predicting the presence of high-grade prostate cancer (Gleason score 7 or more). We evaluated data from 1000 men with PSA less than 50 ng/mL, who underwent prostate biopsy. A prostate cancer was found in 313 (31%), and in 172 (17.2%) we detected high-grade prostate cancer. With those data, we developed 2 Co-Active Neuro-Fuzzy Inference Systems to predict the presence of high-grade prostate cancer. The first model had four input neurons (PSA, free PSA percentage [%freePSA], PSA density, and age) and the second model had three input neurons (PSA, %freePSA, and age). The model with four input neurons (PSA, %freePSA, PSA density, and age) showed better performances than the one with three input neurons (PSA, %freePSA, and age). In fact the average testing error was 0.42 for the model with four input neurons and 0.44 for the other model. The addition of PSA density to the model has allowed to obtain better results for the diagnosis of high grade prostate cancer.

  17. Motivation in Physical Education classes of senior high school grades

    Directory of Open Access Journals (Sweden)

    Karen Cristina Chicati

    2008-06-01

    Full Text Available The aim of the present investigation was to make a diagnosis and analyze students’ motivation in Physical Education classes of the senior high school of the public school system in the city of Maringá, state of Paraná, Brazil. This descriptive research comprised a population of 12,889 students, males and females, with 15-to-17-year average age, enrolled in the three grades of senior high school. The sample comprised 240 students randomly selected from four schools: 60 students per school, 20 from each grade, 10 males and 10 females. A questionnaire constituted by 16 mixed questions was applied to the students. The data were analyzed through frequency and percentage calculus. The results demonstrated that Physical Education classes are not so highly motivated, once the students have been given the same contents since the first grades, prevailing sports. Command and open teaching have been the most frequently used methodology, despite most of the students answering that they do what they want to in class. Evaluation comprises attendance and theoretical/practical classes. The students demonstrated a strong interest in classes, but those who are not so much interested answered that the classes were demotivating, besides backing appropriate materials and space. Thus it may be concluded that students motivation in Physical Education classes in the senior high school grades is not so clear.

  18. Functionally graded materials produced with high power lasers

    NARCIS (Netherlands)

    De Hosson, J. T. M.; Ocelik, V.; Chandra, T; Torralba, JM; Sakai, T

    2003-01-01

    In this keynote paper two examples will be present of functionally graded materials produced with high power Nd:YAG lasers. In particular the conditions for a successful Laser Melt Injection (LMI) of SiC and WC particles into the melt pool of A18Si and Ti6Al4V alloys are presented. The formation of

  19. Levetiracetam improves verbal memory in high-grade glioma patients

    NARCIS (Netherlands)

    de Groot, Marjolein; Douw, Linda; Sizoo, Eefje M; Bosma, Ingeborg; Froklage, Femke E; Heimans, Jan J; Postma, Tjeerd J; Klein, Martin; Reijneveld, Jaap C

    BACKGROUND: Treatment of high-grade glioma (HGG) patients with anti-epileptic drugs (AEDs) has met with various side effects, such as cognitive deterioration. The cognitive effects of both older and newer AEDs in HGG patients are largely unknown. The aim of this study was to determine the effect of

  20. A new specimen for out-of-plane shear strength of advanced high strength steel sheets

    Science.gov (United States)

    Gu, B.; He, J.; Li, S. H.; Zhao, Y. X.; Li, Y. F.; Zeng, D.; Xia, Z. C.; Lin, Z. Q.

    2017-09-01

    Compared with the conventional steels, “shear fracture” is one of the main issues for advanced high strength steels (AHSS). Due to rolling, anisotropy is an intrinsic property for sheet metals. Not only the plastic responses of sheet metals but also the fracture strengths are orientation dependent. In the small radius forming process, for example, the stretch-bending deformation of sheet metals under small radius condition, the normal stress cannot be neglected. Three-dimensional loading condition constructs complex shear stress states of sheet metals especially the out-of-plane shear stress. The out-of-plane performance must be considered in order to better understand the “shear fracture” phenomenon of AHSS. Compared to in-plane shear test, the out-of-plane shear test is more difficult to carry out due to the severe restriction of the dimensions in the thickness direction. In this paper, a new specimen is presented for out-of-plane shear test. Failure of the specimen occurs in shear between two centrally located notches machined halfway through its thickness from opposing sides. Meanwhile, the finite element (FE) model and possible failure modes of this specimen are investigated in detail. At last, brief experimental results between out-of-plane shear fracture strength and the in-plane shear fracture strength are compared for DP980 sheets.

  1. Product Design and Production Practice of 700MPa High Strength Hot Rolled Strip for Auto Axle Tube

    Science.gov (United States)

    Hui, Pan; Zhao-dong, Wang; Ya-jun, Hui; Yang, Cui; Xiang-tao, Deng; Chun-lin, Bao

    According to the technical specifications of 700MPa high strength automotive axle tube steel, a low cost of 0.07%C+1.5%Mn+0.05%Nb+0.10%Ti was designed. The high strength mainly relies on grain refinement strengthening and precipitation strengthening. The recrystallization, precipitation, and CCT curves of the 700MPa grade axle tube steel were studied in order to determine a reasonable TMCP process. By controlling the low level segregation band, low level of C and N content, 700MPa grade high strength automotive axle tube steel is successfully developed with excellent mechanical property, welding property, flattening and flaring property, torsion fatigue property, static torsional property and surface quality.

  2. Transition of endometrial stromal sarcoma into high-grade sarcoma.

    Science.gov (United States)

    Amant, Frederic; Woestenborghs, Heidi; Vandenbroucke, Vanessa; Berteloot, Patrick; Neven, Patrick; Moerman, Philippe; Vergote, Ignace

    2006-12-01

    Endometrial stromal sarcoma typically is of low grade and hormone-sensitive. Although these characteristics result in an indolent behavior, little data are available on the evolution over time. We report on two cases where microscopic and immunohistochemic assessment of the tumor on several occasions during 8 and 25 years of follow up enabled us to document a transition of a low-grade into a high-grade malignancy. These were mainly characterized by increased cellular atypia, absence of spiral arterioles and an increased mitotic index and proliferation index (MIB1). Since this transition was related to clinical loss of hormone sensitivity, the therapeutic approach consisting of hormonal treatment in combination with repetitive surgery was switched to chemotherapy only. These long-term follow up data provide insight in endometrial stromal sarcoma tumor biology and highlight the importance of sampling recurrent tumors to estimate biologic behavior in order to tailor subsequent treatment.

  3. Recent Progress in High Strength Low Carbon Steels

    Directory of Open Access Journals (Sweden)

    Zrník J.

    2006-01-01

    Full Text Available Advanced High Strength (AHS steels, among them especially Dual Phase (DP steels, Transformation Induced Plasticity (TRIP steels, Complex Phase (CP steels, Partially Martensite (PM steels, feature promising results in the field. Their extraordinary mechanical properties can be tailored and adjusted by alloying and processing. The introduction of steels with a microstructure consisting at least of two different components has led to the enlargement of the strength level without a deterioration of ductility. Furthermore, the development of ultra fine-grained AHS steels and their service performance are reviewed and new techniques are introduced. Various projects have been devoted to develop new materials for flat and long steel products for structural applications. The main stream line is High Strength, in order to match the weight lightening requirements that concern the whole class of load bearing structures and/or steel components and one of the most investigated topics is grain refinement.

  4. Profile of high school strength and conditioning coaches.

    Science.gov (United States)

    Duehring, Michael D; Ebben, William P

    2010-02-01

    This study describes the results of a survey of high school strength and conditioning coaches (coaches). Thirty-nine of 128 (30.5%) coaches who were surveyed responded, representing 24 of the states of the United States. This survey examines the coaches' personal background information, compensation, job responsibilities, schools, facilities, the advantages and disadvantages of their positions, things they would like to change, and unique aspects of their program. The coaches averaged 6.74 and 14.89 years in their present positions and profession, respectively. All but one coach was certified, with 83% of the survey respondents certified by the National Strength and Conditioning Association. More than half of the coaches (54%) had master's degrees. Coaches worked an average of 9.13 hours a day, beginning and ending their work day on average at 7:34 and 5:07, am and pm, respectively. Coaches' salaries, normalized to a 12-month contract for comparison, averaged approximately 57,866 dollars and 55,214 dollars for those who were and were not part of the teacher's contract, respectively. Coaches who were not salaried were paid an average of $25.90 per hour. Coaches functioned in a variety of roles in their school in addition to their work as a strength and conditioning coach. The coaches' schools averaged approximately 1475 and 429 students and student athletes, respectively. The average strength and conditioning facility size was approximately 3631 ft, resulting in an average of 9.92 ft per athlete. Daily use averaged approximately 192 students. Coaches described the types of equipment and a variety of other facilities used to train athletes. Coaches also reported the advantages, disadvantages, and unique aspects of their work in high school strength and conditioning. Thirty-three of 39 coaches desired to continue as a high school strength and conditioning coach. A variety of other data are described. This study serves as a comprehensive source of information about

  5. The Tensile Behavior of High-Strength Carbon Fibers.

    Science.gov (United States)

    Langston, Tye

    2016-08-01

    Carbon fibers exhibit exceptional properties such as high stiffness and specific strength, making them excellent reinforcements for composite materials. However, it is difficult to directly measure their tensile properties and estimates are often obtained by tensioning fiber bundles or composites. While these macro scale tests are informative for composite design, their results differ from that of direct testing of individual fibers. Furthermore, carbon filament strength also depends on other variables, including the test length, actual fiber diameter, and material flaw distribution. Single fiber tensile testing was performed on high-strength carbon fibers to determine the load and strain at failure. Scanning electron microscopy was also conducted to evaluate the fiber surface morphology and precisely measure each fiber's diameter. Fiber strength was found to depend on the test gage length and in an effort to better understand the overall expected performance of these fibers at various lengths, statistical weak link scaling was performed. In addition, the true Young's modulus was also determined by taking the system compliance into account. It was found that all properties (tensile strength, strain to failure, and Young's modulus) matched very well with the manufacturers' reported values at 20 mm gage lengths, but deviated significantly at other lengths.

  6. Forming and bonding techniques for high-strength aluminum alloys

    Science.gov (United States)

    Friedrich, Horst E.

    1995-02-01

    This article highlights the continued preference for aluminum as a structural material for aircraft, where demands for high performance coupled with the need for weight reduction have led to the use of high-strength aluminum alloys. The ever-increasing demand for a high level of integration of complex structural components calls for the development of appropriate manufacturing processes. As an example, superplastic forming is discussed, combined with innovative bonding techniques such as diffusion bonding and adhesive spot welding.

  7. Postheated Model of Confined High Strength Fibrous Concrete

    Directory of Open Access Journals (Sweden)

    Kaleem A. Zaidi

    2016-01-01

    Full Text Available HSC normally suffers from low stiffness and poor strain capacity after exposure to high temperature. High strength confined fibrous concrete (HSCFC is being used in industrial structures and other high rise buildings that may be subjected to high temperature during operation or in case of an accidental fire. The proper understanding of the effect of elevated temperature on the stress-strain relationship of HSCFC is necessary for the assessment of structural safety. Further stress-strain model of HSCFC after exposure to high temperature is scarce in literature. Experimental results are used to generate the complete stress-strain curves of HSCFC after exposure to high temperature in compression. The variation in concrete mixes was achieved by varying the types of fibre, volume fraction of fibres, and temperature of exposure from ambient to 800°C. The degree of confinement was kept constant in all the specimens. A comparative assessment of different models on the high strength confined concrete was also conducted at different temperature for the accuracy of proposed model. The proposed empirical stress-strain equations are suitable for both high strength confined concrete and HSCFC after exposure to high temperature in compression. The predictions were found to be in good agreement and well fit with experimental results.

  8. Experimental characterization and modeling of the creep strength at 550 C of ASME Grade 92 steel welded joints

    International Nuclear Information System (INIS)

    Kalck, Ch.

    2012-01-01

    In the framework of the development of Generation IV nuclear power plants, ASME Grade 92 ferritic-martensitic steel is a candidate material for components subjected to long-term creep at high temperature. The aim of this study is to characterize the microstructure of Grade 92 butt welded joints and to model their creep behavior at 550 C. Two filler rods were used for this study. The microstructure of the different weld regions was quantitatively characterized. In order to understand the weaker mechanical properties of the ICHAZ compared to the other regions of the welded joint, the microstructures of the base metal and the ICHAZ were compared at different scales (SEM, EBSD, TEM on thin foils and extractive replicas). No significant difference regarding micro-texture, sub-structure and precipitation state was highlighted between both microstructures. The origin of the weaker resistance of the ICHAZ to viscoplastic flow is still not fully understood. A softer zone was found in the base metal close to the ICHAZ, yet with finer sub-grains than the base metal. It was supposed to be a thermo-mechanically-affected zone (TMAZ). At high temperatures and low stress levels, Grade 92 welded joints may be sensitive to type IV cracking, which occurs in the inter-critical heat affected zone (ICHAZ). Creep tests conducted at 550 C on cross-weld specimens revealed that fracture takes place in the ICHAZ, even for short-term creep tests (i.e., lifetime lower than 1000 h). In order to model the creep behavior of the welded joint, viscoplastic constitutive equations for the different regions of the weld assembly were required. The viscoplastic behavior of the base metal, weld metal and of the ICHAZ were modeled using a phenomenological approach. The viscoplastic flow behavior of the weld metal and of the ICHAZ was experimentally determined (i) from tensile tests with displacement field measurements and (ii) from creep tests on tensile bars notched in the region of interest. An

  9. Comparative study of the shear bond strength of various veneering materials on grade II commercially pure titanium.

    Science.gov (United States)

    Lee, Eun-Young; Jun, Sul-Gi; Wright, Robert F; Park, Eun-Jin

    2015-02-01

    To compare the shear bond strength of various veneering materials to grade II commercially pure titanium (CP-Ti). Thirty specimens of CP-Ti disc with 9 mm diameter and 10 mm height were divided into three experimental groups. Each group was bonded to heat-polymerized acrylic resin (Lucitone 199), porcelain (Triceram), and indirect composite (Sinfony) with 7 mm diameter and 2 mm height. For the control group (n=10), Lucitone 199 were applied on type IV gold alloy castings. All samples were thermocycled for 5000 cycles in 5-55℃ water. The maximum shear bond strength (MPa) was measured with a Universal Testing Machine. After the shear bond strength test, the failure mode was assessed with an optic microscope and a scanning electron microscope. Statistical analysis was carried out with a Kruskal-Wallis Test and Mann-Whitney Test. The mean shear bond strength and standard deviations for experimental groups were as follows: Ti-Lucitone 199 (12.11 ± 4.44 MPa); Ti-Triceram (11.09 ± 1.66 MPa); Ti-Sinfony (4.32 ± 0.64 MPa). All of these experimental groups showed lower shear bond strength than the control group (16.14 ± 1.89 MPa). However, there was no statistically significant difference between the Ti-Lucitone 199 group and the control group, and the Ti-Lucitone 199 group and the Ti-Triceram group. Most of the failure patterns in all experimental groups were adhesive failures. The shear bond strength of veneering materials such as heat-polymerized acrylic resin, porcelain, and indirect composite to CP-Ti was compatible to that of heatpolymerized acrylic resin to cast gold alloy.

  10. Rheology of High-Melt-Strength Polypropylene for Additive Manufacturing

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Kamleitner, Florian; Jagenteufel, Ralf

    Acrylonitrile butadiene styrene (ABS) is a widely used material for additive manufacturing (AM) fused deposition modeling (FDM). The rheological properties of high-melt-strength polypropylene (HMS-PP) were compared to commercially available ABS 250 filament to study the possibility of using this ...

  11. Influence of curing regimes on compressive strength of ultra high ...

    Indian Academy of Sciences (India)

    The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the ...

  12. Fatigue experiments on connections made of very high strength steels

    NARCIS (Netherlands)

    Pijpers, R.; Kolstein, H.; Bijlaard, F.

    2013-01-01

    An effective application of Very High Strength Steels (VHSS) can be expected in truss-like structures, typically made of hollow sections. Improved design of VHSS truss structures could incorporate the application of cast joints, since an appropriate design of cast joints limits the stress

  13. Crack formation and fracture energy of normal and high strength ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. The crack path through composite materials such as concrete depends on the mechanical interaction of inclusions with the cement-based matrix. Fracture energy depends on the deviations of a real crack from an idealized crack plane. Fracture energy and strain softening of normal, high strength, and self- ...

  14. Performance assessment on high strength steel endplate connections after fire

    NARCIS (Netherlands)

    Qiang, X.; Wu, N.; Jiang, X.; Bijlaard, F.S.K.; Kolstein, M.H.

    2017-01-01

    Purpose – This study aims to reveal more information and understanding on performance and failure mechanisms of high strength steel endplate connections after fire. Design/methodology/approach – An experimental and numerical study on seven endplate connections after

  15. Anaerobic dynamic membrane bioreactors for high strength wastewater treatment

    NARCIS (Netherlands)

    Ersahin, M.E.; Gimenez Garcia, J.B.; Ozgun, H.; Tao, Y.; Van Lier, J.B.

    2013-01-01

    A laboratory scale external anaerobic dynamic membrane bioreactor (AnDMBR) treating high strength wastewater was operated to assess the effect of gas sparging velocity and organic loading rate on removal efficiency and dynamic membrane (DM) filtration characteristics. An increase in gas sparging

  16. A calculation method of cracking moment for the high strength ...

    Indian Academy of Sciences (India)

    Department of Civil Engineering, Karadeniz Technical University, Trabzon,. 61080 ... the properties of ordinary concrete in design of reinforced sections. ...... Thesis, University of. Toronto. Mohammadizadeh M R and Fadaee M J 2009 Torsional behaviour of high-strength concrete beams strengthened using CFRP sheets; ...

  17. Effect of microstructure on the high temperature strength of nitride ...

    Indian Academy of Sciences (India)

    Unknown

    Effect of microstructure on the high temperature strength of nitride bonded silicon carbide composite. J RAKSHIT and P K DAS*. Central Glass and Ceramic Research Institute, Kolkata 700 032, India. MS received 15 March 2002; revised 3 August 2002. Abstract. Four compositions of nitride bonded SiC were fabricated with ...

  18. Impact toughness of high strength low alloy TMT reinforcement ...

    Indian Academy of Sciences (India)

    Unknown

    to formulate a test procedure for Charpy testing of TMT rebar. In this paper the CVN impact toughness of some. 600 MPa yield stress TMT rebars has been discussed with particular reference to the effects of phosphorus, molybdenum and chromium on toughness. 2. Materials and test procedures. Steel for high strength TMT ...

  19. Modelling of tension stiffening for normal and high strength concrete

    DEFF Research Database (Denmark)

    Christiansen, Morten Bo; Nielsen, Mogens Peter

    1998-01-01

    form the model is extended to apply to biaxial stress fields as well. To determine the biaxial stress field, the theorem of minimum complementary elastic energy is used. The theory has been compared with tests on rods, disks, and beams of both normal and high strength concrete, and very good results...

  20. Low velocity impact behaviour of ultra high strength concrete panels

    Indian Academy of Sciences (India)

    oped to simulate the impact behaviour of UHSC panel. The Brittle cracking model is used to simulate the behaviour of UHSC panel under impact loading and to perform parametric studies by varying the volume fraction of steel fibres. Keywords. Ultra high strength concrete; panel; drop weight test; impact analysis;. ABAQUS.

  1. A calculation method of cracking moment for the high strength ...

    Indian Academy of Sciences (India)

    In this study, a method is given to calculate cracking moments of high strength reinforced concrete beams under the effect of pure torsion. To determine the method, both elastic and plastic theories were used. In this method, dimensions of beam cross-section were considered besides stirrup and longitudinal reinforcements.

  2. Investigation of stress–strain models for confined high strength ...

    Indian Academy of Sciences (India)

    The ascending branch of stress–strain curves depended on the ratio of confinement reinforcement was similar to the modified Kent–Park model and the descending branch similar to the Nagashima model. Keywords. High strength concrete; confined concrete; stress–strain models; ductility toughness. 1. Introduction.

  3. Fabrication of carbon film composites for high-strength structures

    Science.gov (United States)

    Preiswerk, P. R.; Lippman, M.

    1972-01-01

    Physical and mechanical properties of fiber composite materials consisting of carbon films are described. Application of carbon film structural composites for constructing microwave filters or optical instruments is proposed. Applications in aerospace and architectural structures for high strength and low density properties are discussed.

  4. Strength Development of High-Strength Ductile Concrete Incorporating Metakaolin and PVA Fibers

    Directory of Open Access Journals (Sweden)

    Muhammad Fadhil Nuruddin

    2014-01-01

    Full Text Available The mechanical properties of high-strength ductile concrete (HSDC have been investigated using Metakaolin (MK as the cement replacing material and PVA fibers. Total twenty-seven (27 mixes of concrete have been examined with varying content of MK and PVA fibers. It has been found that the coarser type PVA fibers provide strengths competitive to control or higher than control. Concrete with coarser type PVA fibers has also refined microstructure, but the microstructure has been undergone with the increase in aspect ratio of fibers. The microstructure of concrete with MK has also more refined and packing of material is much better with MK. PVA fibers not only give higher stiffness but also showed the deflection hardening response. Toughness Index of HSDC reflects the improvement in flexural toughness over the plain concrete and the maximum toughness indices have been observed with 10% MK and 2% volume fraction of PVA fibers.

  5. Strength development of high-strength ductile concrete incorporating Metakaolin and PVA fibers.

    Science.gov (United States)

    Nuruddin, Muhammad Fadhil; Khan, Sadaqat Ullah; Shafiq, Nasir; Ayub, Tehmina

    2014-01-01

    The mechanical properties of high-strength ductile concrete (HSDC) have been investigated using Metakaolin (MK) as the cement replacing material and PVA fibers. Total twenty-seven (27) mixes of concrete have been examined with varying content of MK and PVA fibers. It has been found that the coarser type PVA fibers provide strengths competitive to control or higher than control. Concrete with coarser type PVA fibers has also refined microstructure, but the microstructure has been undergone with the increase in aspect ratio of fibers. The microstructure of concrete with MK has also more refined and packing of material is much better with MK. PVA fibers not only give higher stiffness but also showed the deflection hardening response. Toughness Index of HSDC reflects the improvement in flexural toughness over the plain concrete and the maximum toughness indices have been observed with 10% MK and 2% volume fraction of PVA fibers.

  6. Theoretical design and advanced microstructure in super high strength steels

    International Nuclear Information System (INIS)

    Caballero, F.G.; Santofimia, M.J.; Garcia-Mateo, C.; Chao, J.; Garcia de Andres, C.

    2009-01-01

    A theoretical design procedure based on phase transformation theory alone has been successfully applied to design steels with a microstructure consisting of a mixture of bainitic ferrite and retained austenite. Using thermodynamics and kinetics models, a set of four carbide free bainitic steels with a 0.3 wt.% carbon content were designed and manufactured following a thermomechanical treatment consisting of hot rolling and two-step cooling. The designed steels present significant combinations of strength and ductility, with tensile strengths ranging from 1500 to 1800 MPa and total elongations over 15%. However, a carbon content of 0.3 wt.% is still high for in-use properties such as weldability. In this sense, a reduction in the average carbon content of advanced bainitic steels was proposed. Improved bainitic steels with a carbon content of 0.2 wt.% reached combinations of strength and ductility comparable to those in TRIP assisted steels.

  7. Recent trends in steel fibered high-strength concrete

    International Nuclear Information System (INIS)

    Shah, Abid A.; Ribakov, Y.

    2011-01-01

    Highlights: → Recent studies on steel fibred high strength concrete (SFHSC) are reviewed. → Different design provisions for SFHSC are compared. → Applications of SFHSC in new and existing structures and elements are discussed. → Using non-destructive techniques for quality control of SFHSC are reviewed. -- Abstract: Steel fibered high-strength concrete (SFHSC) became in the recent decades a very popular material in structural engineering. High strength attracts designers and architects as it allows improving the durability as well as the esthetics of a construction. As a result of increased application of SFHSC, many experimental studies are conducted to investigate its properties and to develop new rules for proper design. One of the trends in SFHSC structures is to provide their ductile behavior that is desired for proper structural response to dynamic loadings. An additional goal is to limit development and propagation of macro-cracks in the body of SFHSC elements. SFHSC is tough and demonstrates high residual strengths after appearance of the first crack. Experimental studies were carried out to select effective fiber contents as well as suitable fiber types, to study most efficient combination of fiber and regular steel bar reinforcement. Proper selection of other materials like silica fume, fly ash and super plasticizer has also high importance because of the influence on the fresh and hardened concrete properties. Combination of normal-strength concrete with SFHSC composite two-layer beams leads to effective and low cost solutions that may be used in new structures as well as well as for retrofitting existing ones. Using modern nondestructive testing techniques like acoustic emission and nonlinear ultrasound allows verification of most design parameters and control of SFHSC properties during casting and after hardening. This paper presents recent experimental results, obtained in the field SFHSC and non-destructive testing. It reviews the

  8. High Grade Leiomyosarcoma Mimicking a Recurrent Angiomyxoma in the Perineum.

    Science.gov (United States)

    Sood, Neha; Swaika, Abhisek; Hanooshi, Bashar; Waldorf, James; Peterson, Jennifer; Wu, Kevin; Attia, Steven; Dinh, Tri A

    2015-05-05

    Perineal leiomyosarcoma is an extremely rare and aggressive cancer with a high metastatic potential and no defined standard treatment. There are only a few (six) reported cases in the literature. We report the case of a 67-year-old woman with a perineal leiomyosarcoma arising at the same site of a previously resected superficial angiomyxoma. Initially, she was treated for a presumptive recurrence of angiomyxoma. As she did not respond to medical therapy, she underwent repeat surgical excision. Pathology revealed a high grade leiomyosarcoma, histologically strikingly distinct from the initial diagnosis. She received adjuvant local radiation therapy, and remains without evidence of recurrent disease 36 months after completion of all therapy. This is the first reported case of a high grade perineal leiomyosarcoma originating at the same site as a resected benign superficial angiomyxoma. Our case emphasizes the necessity of a prompt histological diagnosis in cases of presumed recurrent perineal angiomyxoma.

  9. High grade leiomyosarcoma mimicking a recurrent angiomyxoma in the perineum

    Directory of Open Access Journals (Sweden)

    Neha Sood

    2015-05-01

    Full Text Available Perineal leiomyosarcoma is an extremely rare and aggressive cancer with a high metastatic potential and no defined standard treatment. There are only a few (six reported cases in the literature. We report the case of a 67-year-old woman with a perineal leiomyosarcoma arising at the same site of a previously resected superficial angiomyxoma. Initially, she was treated for a presumptive recurrence of angiomyxoma. As she did not respond to medical therapy, she underwent repeat surgical excision. Pathology revealed a high grade leiomyosarcoma, histologically strikingly distinct from the initial diagnosis. She received adjuvant local radiation therapy, and remains without evidence of recurrent disease 36 months after completion of all therapy. This is the first reported case of a high grade perineal leiomyosarcoma originating at the same site as a resected benign superficial angiomyxoma. Our case emphasizes the necessity of a prompt histological diagnosis in cases of presumed recurrent perineal angiomyxoma.

  10. Metallurgical and mechanical properties of laser welded high strength low alloy steel.

    Science.gov (United States)

    Oyyaravelu, Ramachandran; Kuppan, Palaniyandi; Arivazhagan, Natarajan

    2016-05-01

    The study aimed at investigating the microstructure and mechanical properties of Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser welded high strength low alloy (HSLA) SA516 grade 70 boiler steel. The weld joint for a 4 mm thick plate was successfully produced using minimum laser power of 2 kW by employing a single pass without any weld preheat treatment. The micrographs revealed the presence of martensite phase in the weld fusion zone which could be due to faster cooling rate of the laser weldment. A good correlation was found between the microstructural features of the weld joints and their mechanical properties. The highest hardness was found to be in the fusion zone of cap region due to formation of martensite and also enrichment of carbon. The hardness results also showed a narrow soft zone at the heat affected zone (HAZ) adjacent to the weld interface, which has no effect on the weld tensile strength. The yield strength and ultimate tensile strength of the welded joints were 338 MPa and 549 MPa, respectively, which were higher than the candidate metal. These tensile results suggested that the laser welding process had improved the weld strength even without any weld preheat treatment and also the fractography of the tensile fractured samples showed the ductile mode of failure.

  11. Effect of formation and state of interface on joint strength in friction stir spot welding for advanced high strength steel sheets

    Science.gov (United States)

    Taniguchi, Koichi; Matsushita, Muneo; Ikeda, Rinsei; Oi, Kenji

    2014-08-01

    The tensile shear strength and cross tension strength of friction stir spot welded joints were evaluated in the cases of lap joints of 270 N/mm2 grade and 980 N/mm2 grade cold rolled steel sheets with respect to the stir zone area, hardness distribution, and interface condition between the sheets. The results suggested that both the tensile shear strength and cross tension strength were based on the stir zone area and its hardness in both grades of steel. The "hook" shape of the interface also affected the joint strength. However, the joining that occurred across the interfaces had a significant influence on the value of the joint strength in the case of the 270 N/mm2 grade steel.

  12. Bainitic high-strength cast iron with globular graphite

    Science.gov (United States)

    Silman, G. I.; Makarenko, K. V.; Kamynin, V. V.; Zentsova, E. A.

    2013-07-01

    Special features of formation of bainitic structures in grayed cast irons are considered. The influence of the graphite phase and of the special features of chemical composition of the iron on the intermediate transformation in high-carbon alloys is allowed for. The range of application of high-strength cast irons with bainitic structure is determined. The paper is the last and unfinished work of G. I. Silman completed by his disciples as a tribute to their teacher.

  13. Metallurgical and mechanical properties of laser welded high strength low alloy steel

    OpenAIRE

    Oyyaravelu, Ramachandran; Kuppan, Palaniyandi; Arivazhagan, Natarajan

    2016-01-01

    The study aimed at investigating the microstructure and mechanical properties of Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser welded high strength low alloy (HSLA) SA516 grade 70 boiler steel. The weld joint for a 4 mm thick plate was successfully produced using minimum laser power of 2 kW by employing a single pass without any weld preheat treatment. The micrographs revealed the presence of martensite phase in the weld fusion zone which could be due to faster cooling rate of the la...

  14. Influence of microstructure of high-strength low-alloy steels on their weldability

    International Nuclear Information System (INIS)

    Cwiek, J.; Labanowski, J.

    2003-01-01

    Microstructure of steel before welding has influence on the steel's susceptibility to cold cracking because it influences hardenability and maximum hardness of heat affected zone (HAZ). Two high-strength low-alloy (HSLA) steel grades 18G2AV and 14HNMBCu, in various heat treatment conditions, were subjected to simulated welding thermal cycles. It was revealed that maximum HAZ hardness is influenced by microstructure presented before thermal cycle was applied. The higher HAZ hardness was observed for quenched and tempered condition, comparing to full annealed and overheated conditions. (author)

  15. Analysis of DTI-Derived Tensor Metrics in Differential Diagnosis between Low-grade and High-grade Gliomas.

    Science.gov (United States)

    Jiang, Liang; Xiao, Chao-Yong; Xu, Quan; Sun, Jun; Chen, Huiyou; Chen, Yu-Chen; Yin, Xindao

    2017-01-01

    Purpose: It is critical and difficult to accurately discriminate between high- and low-grade gliomas preoperatively. This study aimed to ascertain the role of several scalar measures in distinguishing high-grade from low-grade gliomas, especially the axial diffusivity (AD), radial diffusivity (RD), planar tensor (Cp), spherical tensor (Cs), and linear tensor (Cl) derived from diffusion tensor imaging (DTI). Materials and Methods: Fifty-three patients with pathologically confirmed brain gliomas (21 low-grade and 32 high-grade) were included. Contrast-enhanced T1-weighted images and DTI were performed in all patients. The AD, RD, Cp, Cs, and Cl values in the tumor zone, peritumoral edema zone, white matter (WM) adjacent to edema and contralateral normal-appearing white matter (NAWM) were calculated. The DTI parameters and tumor grades were statistically analyzed, and receiver operating characteristic (ROC) curve analysis was also performed. Results: The DTI metrics in the affected hemisphere showed significant differences from those in the NAWM, except for the AD values in the tumor zone and the RD values in WM adjacent to edema in the low-grade groups, as well as the Cp values in WM adjacent to edema in the high-grade groups. AD in the tumor zone as well as Cs and Cl in WM adjacent to edema revealed significant differences between the low- and high-grade gliomas. The areas under the curve (Az) of all three metrics were greater than 0.5 in distinguishing low-grade from high-grade gliomas by ROC curve analysis, and the best DTI metric was Cs in WM adjacent to edema (Az: 0.692). Conclusion: AD in the tumor zone as well as Cs and Cl in WM adjacent to edema will provide additional information to better classify gliomas and can be used as non-invasive reliable biomarkers in glioma grading.

  16. Precipitation Strengthening by Induction Treatment in High Strength Low Carbon Microalloyed Hot-Rolled Plates

    Science.gov (United States)

    Larzabal, G.; Isasti, N.; Rodriguez-Ibabe, J. M.; Uranga, P.

    2018-03-01

    The use of microalloyed steels in the production of thick plates is expanding due to the possibility of achieving attractive combinations of strength and toughness. As market requirements for high strength plates are increasing and new applications require reduced weight and innovative designs, novel approaches to attaining cost-effective grades are being developed. The mechanism of precipitation strengthening has been widely used in thin strip products, since the optimization of the coiling strategy offers interesting combinations in terms of final properties and microalloying additions. Precipitation strengthening in thick plates, however, is less widespread due to the limitation of interphase precipitation during continuous cooling after hot rolling. With the main objective of exploring the limits of this strengthening mechanism, laboratory thermomechanical simulations that reproduced plate hot rolling mill conditions were performed using low carbon steels microalloyed with Nb, NbMo, and TiMo additions. After continuous cooling to room temperature, a set of heat treatments using fast heating rates were applied simulating the conditions of induction heat treatments. An important increase of both yield and tensile strengths was measured after induction treatment without any important impairment in toughness properties. A significant precipitation hardening is observed in Mo-containing grades under specific heat treatment parameters.

  17. Precipitation Strengthening by Induction Treatment in High Strength Low Carbon Microalloyed Hot-Rolled Plates

    Science.gov (United States)

    Larzabal, G.; Isasti, N.; Rodriguez-Ibabe, J. M.; Uranga, P.

    2018-01-01

    The use of microalloyed steels in the production of thick plates is expanding due to the possibility of achieving attractive combinations of strength and toughness. As market requirements for high strength plates are increasing and new applications require reduced weight and innovative designs, novel approaches to attaining cost-effective grades are being developed. The mechanism of precipitation strengthening has been widely used in thin strip products, since the optimization of the coiling strategy offers interesting combinations in terms of final properties and microalloying additions. Precipitation strengthening in thick plates, however, is less widespread due to the limitation of interphase precipitation during continuous cooling after hot rolling. With the main objective of exploring the limits of this strengthening mechanism, laboratory thermomechanical simulations that reproduced plate hot rolling mill conditions were performed using low carbon steels microalloyed with Nb, NbMo, and TiMo additions. After continuous cooling to room temperature, a set of heat treatments using fast heating rates were applied simulating the conditions of induction heat treatments. An important increase of both yield and tensile strengths was measured after induction treatment without any important impairment in toughness properties. A significant precipitation hardening is observed in Mo-containing grades under specific heat treatment parameters.

  18. Corrosion of Steel in High-Strength Self-Compacting Concrete Exposed to Saline Environment

    Directory of Open Access Journals (Sweden)

    Hana A. Yousif

    2014-01-01

    Full Text Available A research work was carried out to investigate the effectiveness of high-strength self-compacting concrete (SF-R in controlling corrosion of embedded steel. Reinforced concrete cylinders and plain cubes were subjected to 5% NaCl solution. Slump flow, J-ring, V-funnel, compressive strength, electrical resistance, and electrochemical tests were conducted. Corrosion resisting characteristics of steel were examined by monitoring corrosion potential, polarization resistance, corrosion currents, and Tafel plots. The relationship between corrosion current density and corrosion potential was established. Results were compared with characteristics of a grade 40 MPa reference concrete (R and grade 70 MPa conventional self-compacting concrete (SP. Results indicated that at 270 days of exposure, the corrosion currents for steel in SF-R were 63- and 16-fold lower compared to those of steel in R and SP concretes, respectively. This concrete showed a considerable increase in electrical resistance and compressive strength of 96 MPa at 28 days of exposure. Relying on corrosion risk classification based on corrosion current densities and corrosion potentials, the steel in SF-R concrete is definitely in the passive condition. The splendid durability performance of steel in SF-R concrete linked to adorable self-compacting features could furnish numerous opportunities for future structural applications in severe environmental conditions.

  19. NEW HIGH STRENGTH AND FASTER DRILLING TSP DIAMOND CUTTERS

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke

    2006-01-31

    The manufacture of thermally stable diamond (TSP) cutters for drill bits used in petroleum drilling requires the brazing of two dissimilar materials--TSP diamond and tungsten carbide. The ENDURUS{trademark} thermally stable diamond cutter developed by Technology International, Inc. exhibits (1) high attachment (shear) strength, exceeding 345 MPa (50,000 psi), (2) TSP diamond impact strength increased by 36%, (3) prevents TSP fracture when drilling hard rock, and (4) maintains a sharp edge when drilling hard and abrasive rock. A novel microwave brazing (MWB) method for joining dissimilar materials has been developed. A conventional braze filler metal is combined with microwave heating which minimizes thermal residual stress between materials with dissimilar coefficients of thermal expansion. The process results in preferential heating of the lower thermal expansion diamond material, thus providing the ability to match the thermal expansion of the dissimilar material pair. Methods for brazing with both conventional and exothermic braze filler metals have been developed. Finite element modeling (FEM) assisted in the fabrication of TSP cutters controllable thermal residual stress and high shear attachment strength. Further, a unique cutter design for absorbing shock, the densification of otherwise porous TSP diamond for increased mechanical strength, and diamond ion implantation for increased diamond fracture resistance resulted in successful drill bit tests.

  20. Management of Patients with High-Grade Glioma

    Directory of Open Access Journals (Sweden)

    Simge Yukse

    2014-11-01

    Full Text Available The scientific basis for the surgical management of patients with glioma is rapidly evolving. The infiltrative nature of these cancers precludes a surgical cure, but despite this, cytoreductive surgery remains central to high-quality patient’s care. In addition to tissue sampling for accurate histopathological diagnosis and molecular genetic characterisation, clinical benefit from decompression of space-occupying lesions and microsurgical cytoreduction has been reported in patients with different grades of glioma. By integrating advanced surgical techniques with molecular genetic characterisation of the disease and targeted radiotherapy and chemotherapy, it is possible to construct a programme of personalised surgical therapy throughout the patient’s journey. The goal of therapeutic packages tailored to each patient is to optimise patient safety and clinical outcome, and must be delivered in a multidisciplinary setting. Here we review the current concepts that underlie surgical management of patients with high-grade glioma.

  1. Developing radiopure copper alloys for high strength low background applications

    Science.gov (United States)

    Suriano, A. M.; Howard, S. M.; Christofferson, C. D.; Arnquist, I. J.; Hoppe, E. W.

    2018-01-01

    High purity copper continues to play an important role for ultra-low-background detectors. Measurements of rare nuclear decays, e.g. neutrinoless double-beta decay, and searches for dark matter can require construction materials that have high thermal and electrical conductivity with bulk radiopurity less than one micro-Becquerel per kilogram. However, experiments currently using components constructed of radiopure electroformed copper struggle with design of structural and mechanical parts due to the physical properties of pure copper. A higher strength material which possesses many of the favorable attributes of copper yet remains radiopure is desired. A number of copper alloying candidates which may provide improved mechanical performance and adequate radiopurity were considered. Development of an electrodeposited copper-chrome alloy from additive-free electrolyte systems is discussed. The resulting material is shown to possess high strength and meets the aforementioned radiopurity goals.

  2. Development of a high strength, hydrogen-resistant austenitic alloy

    International Nuclear Information System (INIS)

    Chang, K.M.; Klahn, D.H.; Morris, J.W. Jr.

    1980-08-01

    Research toward high-strength, high toughness nonmagnetic steels for use in the retaining rings of large electrical generators led to the development of a Ta-modified iron-based superalloy (Fe-36 Ni-3 Ti-3 Ta-0.5 Al-1.3 Mo-0.3 V-0.01 B) which combines high strength with good toughness after suitable aging. The alloy did, however, show some degradation in fatigue resistance in gaseous hydrogen. This sensitivity was associated with a deformation-induced martensitic transformation near the fracture surface. The addition of a small amount of chromium to the alloy suppressed the martensite transformation and led to a marked improvement in hydrogen resistance

  3. Eosinophilic endomyocardial disease due to high grade chest wall sarcoma.

    Science.gov (United States)

    Hussain, A.; Brown, P. J.; Thwaites, B. C.; Hastings, A. G.

    1994-01-01

    Eosinophilic endomyocardial disease is characterised by persisting blood eosinophilia and acute endocardial lesions which progress to endomyocardial fibrosis. In most cases the cause is unknown but it has been described in association with malignant tumours. A fatal case is presented of a 64 year old woman with this disease due to a high grade sarcoma of the chest wall, an association not previously reported. Images PMID:7974303

  4. Oxidation resistant high creep strength austenitic stainless steel

    Science.gov (United States)

    Brady, Michael P.; Pint, Bruce A.; Liu, Chain-Tsuan; Maziasz, Philip J.; Yamamoto, Yukinori; Lu, Zhao P.

    2010-06-29

    An austenitic stainless steel displaying high temperature oxidation and creep resistance has a composition that includes in weight percent 15 to 21 Ni, 10 to 15 Cr, 2 to 3.5 Al, 0.1 to 1 Nb, and 0.05 to 0.15 C, and that is free of or has very low levels of N, Ti and V. The alloy forms an external continuous alumina protective scale to provide a high oxidation resistance at temperatures of 700 to 800.degree. C. and forms NbC nanocarbides and a stable essentially single phase fcc austenitic matrix microstructure to give high strength and high creep resistance at these temperatures.

  5. Durable high strength cement concrete topping for asphalt roads

    Science.gov (United States)

    Vyrozhemskyi, Valerii; Krayushkina, Kateryna; Bidnenko, Nataliia

    2017-09-01

    Work on improving riding qualities of pavements by means of placing a thin cement layer with high roughness and strength properties on the existing asphalt pavement were conducted in Ukraine for the first time. Such pavement is called HPCM (High Performance Cementitious Material). This is a high-strength thin cement-layer pavement of 8-9 mm thickness reinforced with metal or polymer fiber of less than 5 mm length. Increased grip properties are caused by placement of stone material of 3-5 mm fraction on the concrete surface. As a result of the research, the preparation and placement technology of high-strength cement thin-layer pavement reinforced with fiber was developed to improve friction properties of existing asphalt pavements which ensures their roughness and durability. It must be emphasized that HPCM is a fundamentally new type of thin-layer pavement in which a rigid layer of 10 mm thickness is placed on a non-rigid base thereby improving riding qualities of asphalt pavement at any season of a year.

  6. High-energy behavior of field-strength interactions

    International Nuclear Information System (INIS)

    Levin, D.N.

    1976-01-01

    It is known that spontaneously broken gauge theories are the only renormalizable theories of massive spin-one particles with mass dimension less than or equal to 4. This paper describes a search for renormalizable interactions with higher mass dimension. Specifically, we examine the high-energy behavior of a class of models which involve field-strength interactions. Power counting shows that the high-energy behavior of these models is no worse than the naively estimated high-energy behavior of a gauge theory in the U gauge. Therefore, there may be a ''soft'' symmetry-breaking mechanism (for instance, a soft divergence of an antisymmetric tensor current) which enforces renormalizable high-energy behavior in the same way that spontaneously broken gauge invariance guarantees the renormalizability of gauge theories. This hope is supported by the existence of ''gauge theories'' of strings, which describe analogous interactions of strings and field strengths. Unfortunately, this idea is tarnished by explicit calculations in which renormalizability is imposed in the form of unitarity bounds. These unitarity bounds imply that all possible field-strength couplings must be zero and that the remaining interactions describe a spontaneously broken gauge theory. Thus this result supports an earlier conjecture that gauge theories are the only renormalizable theories of massive vector bosons

  7. Formability of new high performance A710 grade 50 structural steel.

    Science.gov (United States)

    2014-01-01

    This project compared the formability of modified ASTM A710 Grade B50 ksi yield strength steel, jointly developed by : Northwestern University and the Illinois Department of Transportation, with ASTM A606 Type 4 weathering steel used in Illinois : an...

  8. Grain refinement of high strength steels to improve cryogenic toughness

    Science.gov (United States)

    Rush, H. F.

    1985-01-01

    Grain-refining techniques using multistep heat treatments to reduce the grain size of five commercial high-strength steels were investigated. The goal of this investigation was to improve the low-temperature toughness as measured by Charpy V-notch impact test without a significant loss in tensile strength. The grain size of four of five alloys investigated was successfully reduced up to 1/10 of original size or smaller with increases in Charpy impact energy of 50 to 180 percent at -320 F. Tensile properties were reduced from 0 to 25 percent for the various alloys tested. An unexpected but highly beneficial side effect from grain refining was improved machinability.

  9. High-strength cellulose/poly(ethylene glycol) gels.

    Science.gov (United States)

    Liang, Songmiao; Wu, Junjie; Tian, Huafeng; Zhang, Lina; Xu, Jian

    2008-01-01

    Cellulose gel membranes have been prepared by a pre-gelation method employing cellulose solutions in aqueous NaOH-thiourea obtained at low temperature. The cellulose gels were then swollen by low-molecular-weight polyethylene glycol (PEG; MWcellulose/PEG gels were studied by various techniques. The gels exhibit high mechanical performance, and the tensile strength of the gel membranes increases sharply with an increase in the molecular weight of PEG from 200 to 800 g mol(-1). Moreover, their elongation at break remains stable at 100 %. PEG800 efficiently improves the optical transmittance of the gel membranes at ambient temperature, which is about five times greater than that of a normal cellulose hydrogel membrane. A strong hydrogen-bonding interaction occurs between PEG and cellulose leading to a homogeneous structure, high mechanical strength and good transparency of the gel membranes.

  10. Biomechanics of high-grade spondylolisthesis with and without reduction.

    Science.gov (United States)

    Wang, Wenhai; Aubin, Carl-Eric; Cahill, Patrick; Baran, George; Arnoux, Pierre-Jean; Parent, Stefan; Labelle, Hubert

    2016-04-01

    The clinical advantages of reducing spondylolisthesis over fusion in situ have several intuitive reasons such as restore the spinal column into a more anatomic relationship and alignment. However, there is only little evidence in the literature supporting the theoretical advantages of reduction, and its effect on spinopelvic alignment remains poorly defined. In this study, a comprehensive finite element model was developed to analyze the biomechanics of the spine after spinal fusion at L5-S1 in both types of high-grade spondylolisthesis (balanced and unbalanced pelvis). The relevant clinical indices (i.e. spondylolisthesis grade and Dubousset lumbosacral angle), the displacement of L4-L5, pressure within the annulus and nucleus, and stress at L4-L5 were evaluated and compared. The model can well predict the changes of the important clinical indices during the surgery. For a balanced pelvis, the reduction has a minimal effect on the biomechanical conditions at the adjacent level during postsurgical activities. In the unbalanced case, reduction induced larger deformation in the lumbosacral region and a higher stress concentration at adjacent level. Whether such a stress concentration can lead to long-term disc degeneration is not known. The results provide additional information for the clinician considering reduction of high-grade spondylolisthesis.

  11. submitter Physical Properties of a High-Strength Austenitic Stainless Steel for the Precompression Structure of the ITER Central Solenoid

    CERN Document Server

    Sgobba, Stefano; Arauzo, Ana; Roussel, Pascal; Libeyre, Paul

    2016-01-01

    The ITER central solenoid (CS) consists of six independent coils kept together by a precompression support structure that must react vertical tensile loads and provide sufficient preload to maintain coil-to-coil contact when the solenoid is energized. The CS precompression system includes tie plates, lower and upper key blocks, load distribution and isolation plates and other attachment, support and insulating hardware. The tie plates operating at 4 K are manufactured starting from forgings in a high-strength austenitic stainless steel (FXM-19) with a stringent specification. Moreover, forged components for the lower and upper key blocks have to be provided in the same FXM-19 grade with comparably strict requirements. FXM-19 is a high-nitrogen austenitic stainless steel, featuring high strength and toughness, ready weldability, and forgeability. It features as well higher integral thermal contraction down to 4 K compared with the very high Mn steel grade selected for the CS coil jackets, hence providing an ad...

  12. Rheology of high melt strength polypropylene for additive manufacturing

    OpenAIRE

    Jagenteufel, Ralf; Hofstätter, Thomas; Kamleitner, Florian; Pedersen, David Bue; Tosello, Guido; Hansen, Hans Nørgaard

    2017-01-01

    Rheological measurements of high melt strength polypropylene (HMS-PP) were used in order to generate master curves describing the shear-dependent viscosity in comparison to acrylonitrile butadiene styrene copolymer (ABS). The latter material showed specific disadvantages in terms of thermal stability, whereas HMS-PP showed a more stable behavior at the investigated temperatures. Hereafter, the material was used in a fused deposition modeling additive manufacturing process, focusing on the inv...

  13. Localized bending fatigue behavior of high-strength steel monostrands

    DEFF Research Database (Denmark)

    Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.

    2012-01-01

    In this paper, the localized bending fatigue behavior of pretensioned high strength steel monostrands is investigated. Furthermore, a new methodology using an optical photogrammetry system, which can quantify surface deformations on the strand is presented. The system allows measurement of the st...... displacement (opening/closing and sliding) of the helically wound wires. Moreover, the results are a step towards understanding the bending fatigue damage mechanisms of monostrand cables....

  14. Perspectives on coated advanced high strength steels for automotive applications

    OpenAIRE

    Bhattacharya, D.

    2011-01-01

    Advanced High Strength Steels (AHSS) is the fastest growing segment of sheet products in the automotiveindustry. Coated (galvanized or galvannealed) AHSS are the most important of this class of steels. AHSSincludes various families of steels, major among them being dual-phase, multi-phase or complex-phase, TRIPand martensitic steels. Recently, Twin Induced Plasticity (TWIP) and Quenching and Partitioning (QP) steelsare also becoming popular. Finally, press-hardened steels (PHS) are increasing...

  15. Lightweight High Strength Concrete with Expanded Polystyrene Beads

    OpenAIRE

    Subhan, Tengku Fitriani L

    2006-01-01

    This paper is a literature study about lightweight high strength concrete by incorporating expanded polystyrene beads. Basically polystyrene is disposal material from packaging industry. However, after being processed in a special manner, polystyrene can be expanded and used as lightweight concrete making material. Therefore, the use of expanded polystyrene beads in concrete is not only beneficial for engineering studies but also provide solution for the environmental problem

  16. High Strength, Nano-Structured Mg-Al-Zn Alloy

    Science.gov (United States)

    2011-01-01

    samples with no porosity and straightforward processing routes. How- ever, these studies reveal that structural evolution of Mg during warm ECAP ...REPORT High strength, nano-structured Mg –Al–Zn alloy 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: The mechanical behavior and microstructure of...nanocrystalline (nc) Mg AZ80 alloy, synthesized via a cryomilling and spark plasma sintering (SPS) approach are reported and discussed. The effects of

  17. Getting High School Students Ready for College: A Quantitative Study of Standards-Based Grading Practices

    Science.gov (United States)

    Townsley, Matt; Varga, Matt

    2018-01-01

    Some high schools are moving towards standards-based grading in an attempt to produce consistent grading practices; however, the change's impact on college readiness is not clear. The purpose of this study was to explore the effect of high school's grading practices as it relates to ACT scores and grade point averages (GPAs). Existing data were…

  18. Multiphoton imaging of low grade, high grade intraepithelial neoplasia and intramucosal invasive cancer of esophagus

    Science.gov (United States)

    Xu, Jian; Jiang, Liwei; Kang, Deyong; Wu, Xuejing; Xu, Meifang; Zhuo, Shuangmu; Zhu, Xiaoqin; Lin, Jiangbo; Chen, Jianxin

    2017-04-01

    Esophageal squamous cell carcinoma (ESCC) is devastating because of its aggressive lymphatic spread and clinical course. It is believed to occur through low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), and intramucosal invasive cancer (IMC) before transforming to submucosal cancer. In particular, these early lesions (LGIN, HGIN and IMC), which involve no lymph node nor distant metastasis, can be cured by endoscopic treatment. Therefore, early identification of these lesions is important so as to offer a curative endoscopic resection, thus slowing down the development of ESCC. In this work, spectral information and morphological features of the normal esophageal mucosa are first studied. Then, the morphological changes of LGIN, HGIN and IMC are described. Lastly, quantitative parameters are also extracted by calculating the nuclear-to-cytoplasmic ratio of epithelial cells and the pixel density of collagen in the lamina propria. These results show that multiphoton microscopy (MPM) has the ability to identify normal esophageal mucosa, LGIN, HGIN and IMC. With the development of multiphoton endoscope systems for in vivo imaging, combined with a laser ablation system, MPM has the potential to provide immediate pathologic diagnosis and curative treatment of ESCC before the transformation to submucosal cancer in the future.

  19. Development of ductile high-strength chromium alloys, phase 2

    Science.gov (United States)

    Filippi, A. M.

    1973-01-01

    Strength and ductility were evaluated for chromium alloys dispersion hardened with the putative TaC, TaB, CbC, and CbB compounds. TaC and TaB proved to be the most potent strengtheners, but when combined, their effect far outweighed that produced individually. Tests at 1422 K (2100 F) on an alloy containing these two compounds at the combined level of 0.5 m/o revealed a 495 MN/sq m (70 ksi) tensile strength for wrought material, and a 100 hour rupture strength of 208 MN/sq m (30 ksi) when solution annealed and aged to maximize creep resistance. These levels of high temperature strength greatly exceed that reported for any other chromium-base alloy. The ductile-to-brittle transition temperature (DBTT) of the two phase strengthened alloy occurred at approximately 588 K (600 F) when heat treated to optimize creep strength and was not improved by fabrication to produce a wrought and recovered microstructure. The lowest DBTT measured on any of the alloys investigated was 422 K (300 F). Strengthening phases actually formed in Cr-Ta-B and Cr-Cb-B compositions are probable M2CrB2 (M=Ta or Cb) compounds of tetragonal crystal structure. The likely habit relationship between these compounds and chromium is postulated. Cube habit coherency was identified for TaC precipitation in chromium by electron microscopy. In another study, the maximum solubility of carbon in chromium was indicated to lie between 3/4 and 1 a/o and that of boron to be 1/2 a/o.

  20. Dynamic Strength of Metals at High Pressure and Strain Rate

    Science.gov (United States)

    Lorenz, Thomas

    2006-03-01

    A new approach to materials science at very high pressures and strain rates has been developed on the Omega laser, using a ramped plasma piston drive. A laser drives an ablative shock through a solid plastic reservoir where it unloads at the rear free surface, expands across a vacuum gap, and stagnates on the metal sample under study. This produces a gently increasing ram pressure, compressing the sample nearly isentropically. The peak pressure on the sample, diagnosed with VISAR measurements, can be varied by adjusting the laser energy and pulse length, gap size, and reservoir density, and obeys a simple scaling relation.^1 This has been demonstrated at OMEGA at pressures to 200 GPa in Al foils. In an important application, using in-flight x-ray radiography, the material strength of solid-state samples at high pressure can be inferred by measuring the reductions in the growth rates (stabilization) of Rayleigh-Taylor (RT) unstable interfaces. RT instability measurements of solid of Al-6061-T6 ^2 and vanadium, at pressures of 20-100 GPa, and strain rates of 10^6 to 10^8 s-1, show clear material strength effects. Modelling results for two constitutive strength models -- Steinberg-Guinan and Preston-Tonks-Wallace, show enhanced dynamic strength that may be correlated with a high-strain-rate, phono-drag mechanism. Data, modeling details and future prospects for this project using the National Ignition Facility laser, will be presented. [1] J. Edwards et al., Phys. Rev. Lett., 92, 075002 (2004). [2] K. T. Lorenz et al., Phys. Plasmas 12, 056309 (2005). This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

  1. An investigation on high temperature fatigue properties of tempered nuclear-grade deposited weld metals

    Science.gov (United States)

    Cao, X. Y.; Zhu, P.; Yong, Q.; Liu, T. G.; Lu, Y. H.; Zhao, J. C.; Jiang, Y.; Shoji, T.

    2018-02-01

    Effect of tempering on low cycle fatigue (LCF) behaviors of nuclear-grade deposited weld metal was investigated, and The LCF tests were performed at 350 °C with strain amplitudes ranging from 0.2% to 0.6%. The results showed that at a low strain amplitude, deposited weld metal tempered for 1 h had a high fatigue resistance due to high yield strength, while at a high strain amplitude, the one tempered for 24 h had a superior fatigue resistance due to high ductility. Deposited weld metal tempered for 1 h exhibited cyclic hardening at the tested strain amplitudes. Deposited weld metal tempered for 24 h exhibited cyclic hardening at a low strain amplitude but cyclic softening at a high strain amplitude. Existence and decomposition of martensite-austenite (M-A) islands as well as dislocations activities contributed to fatigue property discrepancy among the two tempered deposited weld metal.

  2. Grinding damage assessment on four high-strength ceramics.

    Science.gov (United States)

    Canneto, Jean-Jacques; Cattani-Lorente, Maria; Durual, Stéphane; Wiskott, Anselm H W; Scherrer, Susanne S

    2016-02-01

    The purpose of this study was to assess surface and subsurface damage on 4 CAD-CAM high-strength ceramics after grinding with diamond disks of 75 μm, 54 μm and 18 μm and to estimate strength losses based on damage crack sizes. The materials tested were: 3Y-TZP (Lava), dense Al2O3 (In-Ceram AL), alumina glass-infiltrated (In-Ceram ALUMINA) and alumina-zirconia glass-infiltrated (In-Ceram ZIRCONIA). Rectangular specimens with 2 mirror polished orthogonal sides were bonded pairwise together prior to degrading the top polished surface with diamond disks of either 75 μm, 54 μm or 18 μm. The induced chip damage was evaluated on the bonded interface using SEM for chip depth measurements. Fracture mechanics were used to estimate fracture stresses based on average and maximum chip depths considering these as critical flaws subjected to tension and to calculate possible losses in strength compared to manufacturer's data. 3Y-TZP was hardly affected by grinding chip damage viewed on the bonded interface. Average chip depths were of 12.7±5.2 μm when grinding with 75 μm diamond inducing an estimated loss of 12% in strength compared to manufacturer's reported flexural strength values of 1100 MPa. Dense alumina showed elongated chip cracks and was suffering damage of an average chip depth of 48.2±16.3 μm after 75 μm grinding, representing an estimated loss in strength of 49%. Grinding with 54 μm was creating chips of 32.2±9.1 μm in average, representing a loss in strength of 23%. Alumina glass-infiltrated ceramic was exposed to chipping after 75 μm (mean chip size=62.4±19.3 μm) and 54 μm grinding (mean chip size=42.8±16.6 μm), with respectively 38% and 25% estimated loss in strength. Alumina-zirconia glass-infiltrated ceramic was mainly affected by 75 μm grinding damage with a chip average size of 56.8±15.1 μm, representing an estimated loss in strength of 34%. All four ceramics were not exposed to critical chipping at 18 μm diamond grinding. Reshaping a

  3. Fabrication of Hadfield-Cored Multi-layer Steel Sheet by Roll-Bonding with 1.8-GPa-Strength-Grade Hot-Press-Forming Steel

    Science.gov (United States)

    Chin, Kwang-Geun; Kang, Chung-Yun; Park, Jaeyeong; Lee, Sunghak

    2018-03-01

    An austenitic Hadfield steel was roll-bonded with a 1.8-GPa-strength-grade martensitic hot-press-forming (HPF) steel to fabricate a multi-layer steel (MLS) sheet. Near the Hadfield/HPF interface, the carburized and decarburized layers were formed by the carbon diffusion from the Hadfield (1.2%C) to HPF (0.35%C) layers, and could be regarded as kinds of very thin multi-layers of 35 μm in thickness. The tensile test and fractographic data indicated that the MLS sheet was fractured abruptly within the elastic range by the intergranular fracture occurred in the carburized layer. This was because C was mainly segregated at prior austenite grain boundaries in the carburized layer, which weakened grain boundaries to induce the intergranular fracture. In order to solve the intergranular facture problem, the MLS sheet was tempered at 200 °C. The stress-strain curve of the tempered MLS sheet lay between those of the HPF and Hadfield sheets, and a rule of mixtures was roughly satisfied. Tensile properties of the MLS sheet were dramatically improved after the tempering, and the intergranular fracture was erased completely. In particular, the yield strength up to 1073 MPa along with the high strain hardening and excellent ductility of 32.4% were outstanding because the yield strength over 1 GPa was hardly achieved in conventional austenitic steels.

  4. Ti-Al Composite Wires with High Specific Strength

    Directory of Open Access Journals (Sweden)

    Ludwig Schultz

    2011-11-01

    Full Text Available An alternative deformation technique was applied to a composite made of titanium and an aluminium alloy in order to achieve severe plastic deformation. This involves accumulative swaging and bundling. Furthermore, it allows uniform deformation of a composite material while producing a wire which can be further used easily. Detailed analysis concerning the control of the deformation process, mesostructural and microstructural features and tensile testing was carried out on the as produced wires. A strong grain refinement to a grain size of 250–500 nm accompanied by a decrease in 〈111〉 fibre texture component and a change from low angle to high angle grain boundary characteristics is observed in the Al alloy. A strong increase in the mechanical properties in terms of ultimate tensile strength ranging from 600 to 930 MPa being equivalent to a specific strength of up to 223 MPa/g/cm3 was achieved.

  5. Engineered Cooling Process for High Strength Ductile Iron Castings

    Science.gov (United States)

    Lekakh, Simon N.; Mikhailov, Anthony; Kramer, Joseph

    Professor Stefanescu contributed fundamentally to the science of solidification and microstructural evolutions in ductile irons. In this article, the possibility of development of high strength ductile iron by applying an engineered cooling process after casting early shake out from the sand mold was explored. The structures in industrial ductile iron were experimentally simulated using a computer controlled heating/cooling device. CFD modeling was used for process simulation and an experimental bench scale system was developed. The process concept was experimentally verified by producing cast plates with 25 mm wall thickness. The tensile strength was increased from 550 MPa to 1000 MPa in as-cast condition without the need for alloying and heat treatment. The possible practical applications were discussed.

  6. Midwest Joint Venture high-grade uranium mining

    International Nuclear Information System (INIS)

    Fredrickson, H.K.

    1992-01-01

    Midwest Joint Venture (MJV) owns a high-grade uranium deposit in northern Saskatchewan. The deposit is located too deep below surface to be mined economically by open pit methods, and as a consequence, present plans are that it will be mined by underground methods. High-grade uranium ore of the type at MJV, encased in weak, highly altered ground and with radon-rich water inflows, has not before been mined by underground methods. The test mining phase of the project, completed in 1989, had three objectives: To evaluate radiation protection requirements associated with the handling of large quantities of radon-rich water and mining high-grade uranium ore in an underground environment; to investigate the quantity and quality of water inflows into the mine; and, to investigate ground conditions in and around the ore zone as an aid in determining the production mining method to be used. With information gained from the test mining project, a mining method for the production mine has been devised. Level plans have been drawn up, ventilation system designed, pumping arrangements made and methods of ore handling considered. All this is to be done in a manner that will be safe for those doing the work underground. Some of the mining methods planned are felt to be unique in that they are designed to cope with mining problems not known to have been encountered before. New problems underground have required new methods to handle them. Remote drilling, blasting, mucking and backfilling form the basis of the planned mining method

  7. Development of Appropriate Spot Welding Practice for Advanced High Strength Steels (TRP 0114)

    Energy Technology Data Exchange (ETDEWEB)

    Brian Girvin; Warren Peterson; Jerry Gould

    2004-09-17

    This program evaluated the effects of common manufacturing variables on spike-tempering effectiveness. The investigation used design-of-experiment (DOE) techniques, and examined both dual-phase and martensitic grades of high-strength steels (HSS). The specific grades chosen for this project were: Dual-phase (DP) 600, galvannealed (GA), 1.55 mm (DP) 600; Dual-phase (DP) 980 (uncoated), 1.55 mm (DP) 980; and Martensitic (M) 1300, 1.55 mm (M) 1300. Common manufacturing conditions of interest included tempering practice (quench and temper time), button size, simulated part fitup (sheet angular misalignment and fitup), and electrode wear (increased electrode face diameter). All of these conditions were evaluated against mechanical performance (static and dynamic tensile shear). Weld hardness data was also used to examine correlations between mechanical performance and the degree of tempering. Mechanical performance data was used to develop empirical models. The models were used to examine the robustness of weld strength and toughness to the selected processing conditions. This was done using standard EWI techniques. Graphical representations of robustness were then coupled with metallographic data to relate mechanical properties to the effectiveness of spike tempering. Mechanical properties for all three materials were relatively robust to variation in tempering. Major deviations in mechanical properties were caused by degradation of the weld itself. This was supported by a lack of correlation between hardness data and mechanical results. Small button sizes and large electrode face diameters (worn electrodes) produced large reductions in both static and dynamic strength levels when compared to standard production setups. Dynamic strength was further degraded by edge-located welds.

  8. Tetraphenylborate Solubility in High Ionic Strength Salt Solutions

    International Nuclear Information System (INIS)

    Serkiz, S.M.; Ginn, J.D.; Jurgensen, A.R.

    1998-04-01

    Solubility of sodium and potassium salts of the tetraphenylborate ion (TPB) in simulated Savannah River Site High Level Waste was investigated. Data generated from this study allow more accurate predictions of TPB solubility at the In-Tank Precipitation (ITP) facility. Because previous research showed large deviations in the observed solubility of TPB salts when compared with model predictions, additional data were generated to better understand the solubility of TPB in more complex systems of high ionic strength and those containing both potassium and sodium. These data allow evaluation of the ability of current models to accurately predict equilibrium TPB concentrations over the range of experimental conditions investigated in this study

  9. Scratch-resistant, highly conductive, and high-strength carbon nanotube-based composite yarns.

    Science.gov (United States)

    Liu, Kai; Sun, Yinghui; Lin, Xiaoyang; Zhou, Ruifeng; Wang, Jiaping; Fan, Shoushan; Jiang, Kaili

    2010-10-26

    High-strength and conductive carbon nanotube (CNT) yarns are very attractive in many potential applications. However, there is a difficulty when simultaneously enhancing the strength and conductivity of CNT yarns. Adding some polymers into CNT yarns to enhance their strength will decrease their conductivity, while treating them in acid or coating them with metal nanoparticles to enhance their conductivity will reduce their strength. To overcome this difficulty, here we report a method to make high-strength and highly conductive CNT-based composite yarns by using a continuous superaligned CNT (SACNT) yarn as a conductive framework and then inserting polyvinyl alcohol (PVA) into the intertube spaces of the framework through PVA/dimethyl sulphoxide solution to enhance the strength of yarns. The as-produced CNT/PVA composite yarns possess very high tensile strengths up to 2.0 GPa and Young's moduli more than 120 GPa, much higher than those of the CNT/PVA yarns reported. The electric conductivity of as-produced composite yarns is as high as 9.2 × 10(4) S/m, comparable to HNO(3)-treated or Au nanoparticle-coated CNT yarns. These composite yarns are flexible, lightweight, scratch-resistant, very stable in the lab environment, and resistant to extremely humid ambient and as a result can be woven into high-strength and heatable fabrics, showing potential applications in flexible heaters, bullet-proof vests, radiation protection suits, and spacesuits.

  10. How to improve the on-site MOE assessment of old timber beams combining NDT and visual strength grading

    Science.gov (United States)

    Cavalli, Alberto; Togni, Marco

    2013-09-01

    For the conservation and restoration of old timber structures, the knowledge of the mechanical properties of each element is fundamental. For this reason, various nondestructive techniques were developed and investigated since the 1990s. Some of them provide very good results, but the solutions and the proposed models were applied only in few circumstances as a consequence of the on-site restrictive working conditions: no possibility to remove the elements, limitation to ends and faces accessibility and unknown density. The on-site inspection, including the visual strength grading, has been identified as the first step for the timber assessment. In this research, 13 old timber members of Silver Fir (Abies alba Mill.) were visually graded and tested with different nondestructive techniques for the density and modulus of elasticity (MOE) estimation: flexural and longitudinal vibrational tests, stress wave transmission time and Pilodyn penetration depth. The timber elements were also tested in a four-point bending test to determinate the local and global MOE. Finally, a reliable method, applicable to the limiting on-site conditions, was proposed and the results were showed.

  11. Impact strength and abrasion resistance of high strength concrete with rice husk ash and rubber tires

    Directory of Open Access Journals (Sweden)

    M. B. Barbosa

    Full Text Available The paper discusses the application of High Strength Concrete (HSC technology for concrete production with the incorporation of Rice Husk Ash (RHA residues by replacing a bulk of the material caking and rubber tires with partial aggregate volume, assessing their influence on the mechanical properties and durability. For concrete with RHA and rubber, it was possible to reduce the brittleness by increasing the energy absorbing capacity. With respect to abrasion, the RHA and rubber concretes showed lower mass loss than the concrete without residues, indicating that this material is attractive to be used in paving. It is thus hoped that these residues may represent a technological and ecological alternative for the production of concrete in construction works.

  12. Systematics of atom-atom collision strengths at high speeds

    International Nuclear Information System (INIS)

    Gillespie, G.H.; Inokuti, M.

    1980-01-01

    The collision strengths for atom-atom collisions at high speeds are calculated in the first Born approximation. We studied four classes of collisions, distinguished depending upon whether each of the collision partners becomes excited or not. The results of numerical calculations of the collision strengths are presented for all neutral atoms with Z< or =18. The calculations are based on atomic form factors and incoherent scattering functions found in the literature. The relative contribution of each class of collision processes to the total collision cross section is examined in detail. In general, inelastic processes dominate for low-Z atoms, while elastic scattering is more important for large Z. Other systematics of the collision strengths are comprehensively discussed. The relevant experimental literature has been surveyed and the results of this work for the three collision systems H-He, He-He, and H-Ar are compared with the data for electron-loss processes. Finally, suggestions are made for future work in measurements of atom-atom and ion-atom collision cross sections

  13. Review of the corrosion fatigue performance of medium to high strength structural steels

    Energy Technology Data Exchange (ETDEWEB)

    Healy, J.; Billingham, J. [Cranfield Univ. (United Kingdom); Stacey, A.; Simpson, R.; Patel, R. [Health and Safety Executive, London (United Kingdom)

    1996-12-01

    Despite the increasing application in recent years of high strength steels in the offshore industry, their use in the fabrication of conventional jacket structures is generally restricted to steels with yield strengths in the range 450--550 MPa and to topside applications. One reason is the uncertainty associated with the performance of these materials and the concern that such steels have inferior fatigue performance compared to conventional structural steels with typical yield strengths of 350 MPa, particularly when welded and cathodically protected. In this paper, published work from Europe, USA and Japan is reviewed to provide a judgment as to the suitability of these higher strength steels for offshore applications. Fatigue crack propagation data for a range of steels in the yield strength range 400--600 MPa are compared with data for conventional BS4360:50D structural steels. Information for parent plate and heat affected zones is included. The influence of environment is examined and test data for in-air, free corrosion, and cathodic protection potentials ranging from {minus}800 to {minus}1100mV (SCE) are considered. The data for parent materials suggest that comparable or slightly improved performance compared with that of structural Grade 50D steels can be obtained in both air and seawater environments. However, the review highlights the combined detrimental influence of high mean stress and overprotection levels, (i.e., {minus}1100mV), which can cause crack growth rates to be increased by a factor of 10 compared with those observed in-air. The results suggest that welding under controlled conditions does not significantly affect fatigue crack propagation in these steels, with similar corrosion fatigue performance and crack growth mechanisms observed in parent material and in the HAZ.

  14. Irradiation and Bevacizumab in High-Grade Glioma Retreatment Settings

    Energy Technology Data Exchange (ETDEWEB)

    Niyazi, Maximilian; Ganswindt, Ute; Schwarz, Silke Birgit [Department of Radiation Oncology, Ludwig-Maximilians-University Munich, Munich (Germany); Kreth, Friedrich-Wilhelm; Tonn, Joerg-Christian [Department of Neurosurgery, Ludwig-Maximilians-University Munich, Munich (Germany); Geisler, Julia; Fougere, Christian la [Department of Nuclear Medicine, Ludwig-Maximilians-University Munich, Munich (Germany); Ertl, Lorenz; Linn, Jennifer [Department of Neuroradiology, Ludwig-Maximilians-University Munich, Munich (Germany); Siefert, Axel [Department of Radiation Oncology, Ludwig-Maximilians-University Munich, Munich (Germany); Belka, Claus, E-mail: claus.belka@med.uni-muenchen.de [Department of Radiation Oncology, Ludwig-Maximilians-University Munich, Munich (Germany)

    2012-01-01

    Purpose: Reirradiation is a treatment option for recurrent high-grade glioma with proven but limited effectiveness. Therapies directed against vascular endothelial growth factor have been shown to exert certain efficacy in combination with chemotherapy and have been safely tested in combination with radiotherapy in a small cohort of patients. To study the feasibility of reirradiation combined with bevacizumab treatment, the toxicity and treatment outcomes of this approach were analyzed retrospectively. Patients and Methods: After previous treatment with standard radiotherapy (with or without temozolomide) patients with recurrent malignant glioma received bevacizumab (10 mg/kg intravenous) on Day 1 and Day 15 during radiotherapy. Maintenance therapy was selected based on individual considerations, and mainly bevacizumab-containing regimens were chosen. Patients received 36 Gy in 18 fractions. Results: The data of the medical charts of the 30 patients were analyzed retrospectively. All were irradiated in a single institution and received either bevacizumab (n = 20), no additional substance (n = 7), or temozolomide (n = 3). Reirradiation was tolerated well, regardless of the added drug. In 1 patient treated with bevacizumab, a wound dehiscence occurred. Overall survival was significantly better in patients receiving bevacizumab (p = 0.03, log-rank test). In a multivariate proportional hazards Cox model, bevacizumab, Karnovsky performance status, and World Health Organization grade at relapse turned out to be the most important predictors for overall survival. Conclusion: Reirradiation with bevacizumab is a feasible and effective treatment for patients with recurrent high-grade gliomas. A randomized trial is warranted to finally answer the question whether bevacizumab adds substantial benefit to a radiotherapeutic retreatment setting.

  15. Impact of adhesive capsulitis and economic evaluation of high-grade and low-grade mobilisation techniques.

    Science.gov (United States)

    van den Hout, Wilbert B; Vermeulen, Henricus M; Rozing, Piet M; Vliet Vlieland, Thea P M

    2005-01-01

    The purpose of this study was to estimate the impact of adhesive capsulitis on costs and health and to compare the cost-utility of high-grade and low-grade mobilisation techniques. In a randomised controlled trial, 92 patients with adhesive capsulitis received either high-grade mobilisation techniques or low-grade mobilisation techniques and were followed for one year. Outcome measures were quality adjusted life years (QALYs) according to the Short Form 6D (SF-6D) and societal costs estimated from cost questionnaires. Estimated costs and QALYs in both randomisation groups were similar, except for the number of treatment sessions (18.6 for high-grade mobilisation techniques versus 21.5 for low-grade mobilisation techniques), with an estimated cost difference of 105 euros in favour of high-grade mobilisation techniques (p = 0.001, 95% CI 43 euros to 158 euros). In the entire sample, the average valuation of health improved from 0.597 at baseline to 0.745 after a year. The burden due to adhesive capsulitis was estimated at 0.048 QALY and 4,521 euros per patient. About half these costs were due to absenteeism which, during the first quarter, amounted to 38% of the total working hours. In conclusion, the cost-utility analysis does not allow for an evidence-based recommendation on the preferred treatment. Based on the clinical outcome measures, high-grade mobilisation techniques are still preferred to low-grade mobilisation techniques. The estimated substantial burden, both to the patient and to society, suggests that effective early treatment of adhesive capsulitis is warranted to attempt to accelerate recovery.

  16. Magnetic resonance perfusion for differentiating low-grade from high-grade gliomas at first presentation.

    Science.gov (United States)

    Abrigo, Jill M; Fountain, Daniel M; Provenzale, James M; Law, Eric K; Kwong, Joey Sw; Hart, Michael G; Tam, Wilson Wai San

    2018-01-22

    Gliomas are the most common primary brain tumour. They are graded using the WHO classification system, with Grade II-IV astrocytomas, oligodendrogliomas and oligoastrocytomas. Low-grade gliomas (LGGs) are WHO Grade II infiltrative brain tumours that typically appear solid and non-enhancing on magnetic resonance imaging (MRI) scans. People with LGG often have little or no neurologic deficit, so may opt for a watch-and-wait-approach over surgical resection, radiotherapy or both, as surgery can result in early neurologic disability. Occasionally, high-grade gliomas (HGGs, WHO Grade III and IV) may have the same MRI appearance as LGGs. Taking a watch-and-wait approach could be detrimental for the patient if the tumour progresses quickly. Advanced imaging techniques are increasingly used in clinical practice to predict the grade of the tumour and to aid clinical decision of when to intervene surgically. One such advanced imaging technique is magnetic resonance (MR) perfusion, which detects abnormal haemodynamic changes related to increased angiogenesis and vascular permeability, or "leakiness" that occur with aggressive tumour histology. These are reflected by changes in cerebral blood volume (CBV) expressed as rCBV (ratio of tumoural CBV to normal appearing white matter CBV) and permeability, measured by K trans . To determine the diagnostic test accuracy of MR perfusion for identifying patients with primary solid and non-enhancing LGGs (WHO Grade II) at first presentation in children and adults. In performing the quantitative analysis for this review, patients with LGGs were considered disease positive while patients with HGGs were considered disease negative.To determine what clinical features and methodological features affect the accuracy of MR perfusion. Our search strategy used two concepts: (1) glioma and the various histologies of interest, and (2) MR perfusion. We used structured search strategies appropriate for each database searched, which included: MEDLINE

  17. Austenite stability in the high strength metastable stainless steels

    OpenAIRE

    S.J. Pawlak

    2007-01-01

    Purpose: The aim of the present paper was to study the peculiarities of the austenite to martensite phase transformation (A-M), which is an essential step in the production technology of the high strength metastable stainless steels.Design/methodology/approach: The desired control over A-M transformation have been achieved by proper design of the steel chemistry, cold working and heat treatment.Findings: For a range of steel compositions, it was shown that severe cold working leads to fully m...

  18. Diagnostic value of high strength MRCP in the obstructive jaundice

    International Nuclear Information System (INIS)

    Yang Yang; Dong Yuhai; Yin Jie; Lv Guoyi

    2007-01-01

    Objective: To evaluate the diagnostic value of high strength MRCP in patients with obstructive jaundice. Methods: Routine MRI and MRCP examination on 161 patients with obstructive jaundice were carded out with 1.5T Siemens super-conductive magnetic resonance machine. Of them, 103 cases were benign lesions and 58 were malignant after surgical and ERCP pathological confirmation. Results: The diagnostic accuracy of MRCP was 100%, with the qualitative diagnostic accuracy at 90.2%. Conclusion: MRCP was the best method in diagnosing patients with obstructive jaundice, the concerned performances of MRCP could provide the dependable basis for surgical operation project. (authors)

  19. Rheology of high melt strength polypropylene for additive manufacturing

    DEFF Research Database (Denmark)

    Jagenteufel, Ralf; Hofstätter, Thomas; Kamleitner, Florian

    2017-01-01

    Rheological measurements of high melt strength polypropylene (HMS-PP) were used in order to generate master curves describing the shear-dependent viscosity in comparison to acrylonitrile butadiene styrene copolymer (ABS). The latter material showed specific disadvantages in terms of thermal......, adapted parameters for HMS-PP were determined using a fused deposition modeling test bench. The rheological survey clearly showed changes in the melt viscosity of both ABS and HMS-PP due to thermal degradation. However, the comparison of rheological data of the virgin materials with those of printed...

  20. Method for providing a low density high strength polyurethane foam

    Science.gov (United States)

    Whinnery, Jr., Leroy L.; Goods, Steven H.; Skala, Dawn M.; Henderson, Craig C.; Keifer, Patrick N.

    2013-06-18

    Disclosed is a method for making a polyurethane closed-cell foam material exhibiting a bulk density below 4 lbs/ft.sup.3 and high strength. The present embodiment uses the reaction product of a modified MDI and a sucrose/glycerine based polyether polyol resin wherein a small measured quantity of the polyol resin is "pre-reacted" with a larger quantity of the isocyanate in a defined ratio such that when the necessary remaining quantity of the polyol resin is added to the "pre-reacted" resin together with a tertiary amine catalyst and water as a blowing agent, the polymerization proceeds slowly enough to provide a stable foam body.

  1. Localized bending fatigue behavior of high-strength steel monostrands

    DEFF Research Database (Denmark)

    Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.

    2012-01-01

    In this paper, the localized bending fatigue behavior of pretensioned high strength steel monostrands is investigated. Furthermore, a new methodology using an optical photogrammetry system, which can quantify surface deformations on the strand is presented. The system allows measurement...... of the strain distribution in the strand and helps in identifying potential failure mechanisms along the strand and at the wedge location. Initial analysis of the deformations shows that the bending fatigue behavior of the monostrand may be controlled either by local bending deformations or by relative...... displacement (opening/closing and sliding) of the helically wound wires. Moreover, the results are a step towards understanding the bending fatigue damage mechanisms of monostrand cables....

  2. High-Temperature Material Lattice Combining Low Thermal Expansion, High Stiffness and Strength

    Science.gov (United States)

    2009-01-01

    material with superior properties for the high-temperature 14 applications. Nickel- cobalt superalloys exhibit high strength and good creep resistance at...nickel- cobalt alloys showing yield strength vs temperature……30 Figure 10: Comparison chart of nickel- cobalt alloys showing coefficient of thermal...structures that experience high-temperatures reaching 1000oC that use niobium for the low thermal expansion constituent and a nickel- cobalt alloy for

  3. Magnetic Implosion for Novel Strength Measurements at High Strain Rates

    International Nuclear Information System (INIS)

    Lee, H.; Preston, D.L.; Bartsch, R.R.; Bowers, R.L.; Holtkamp, D.; Wright, B.L.

    1998-01-01

    Recently Lee and Preston have proposed to use magnetic implosions as a new method for measuring material strength in a regime of large strains and high strain rates inaccessible to previously established techniques. By its shockless nature, this method avoids the intrinsic difficulties associated with an earlier approach using high explosives. The authors illustrate how the stress-strain relation for an imploding liner can be obtained by measuring the velocity and temperature history of its inner surface. They discuss the physical requirements that lead us to a composite liner design applicable to different test materials, and also compare the code-simulated prediction with the measured data for the high strain-rate experiments conducted recently at LANL. Finally, they present a novel diagnostic scheme that will enable us to remove the background in the pyrometric measurement through data reduction

  4. The treatment of high strength protein wastewater by UASB system

    Directory of Open Access Journals (Sweden)

    Ploypatarapinyo, P.

    2006-01-01

    Full Text Available The objective of this investigation was to treat the high strength protein wastewater by UASB system. The wastewater of this experiment had COD 2,938 mg/l, SS 478 mg/l and total of nitrogen 435 mg/l. The granule was developed from bacteria of activated sludge system as suspended sludge by fermenting anaerobically at 40ºC for 1 month and acclimatizing with the high strength protein wastewater for another month. The MLSS and MLVSS of the started bacterial sludge were 7,105 mg/l and 5,360 mg/l respectively.The maximum organic volume loading of this system was 6 kg COD/m3.d at the hydraulic retention time 12 hrs. The efficiency of COD and BOD removal was 88.38 and 93.07% respectively. The biogas production was 0.52 l/g CODr.d. The content of methane gas was 76.20%. The bacterial suspended sludge was developed to granular sludge with the granule's size of 1.0 mm as 86.02%, 2.05%, 11.84% and 0.09% respectively.

  5. Thermal Stir Welding of High Strength and High Temperature Alloys for Aerospace Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Keystone and MSU team propose to demonstrate the feasibility of solid-state joining high strength and temperature alloys utilizing the Thermal Stir Welding...

  6. High-Grade Leiomyosarcoma Arising in a Previously Replanted Limb

    Directory of Open Access Journals (Sweden)

    Tiffany J. Pan

    2015-01-01

    Full Text Available Sarcoma development has been associated with genetics, irradiation, viral infections, and immunodeficiency. Reports of sarcomas arising in the setting of prior trauma, as in burn scars or fracture sites, are rare. We report a case of a leiomyosarcoma arising in an arm that had previously been replanted at the level of the elbow joint following traumatic amputation when the patient was eight years old. He presented twenty-four years later with a 10.8 cm mass in the replanted arm located on the volar forearm. The tumor was completely resected and pathology examination showed a high-grade, subfascial spindle cell sarcoma diagnosed as a grade 3 leiomyosarcoma with stage pT2bNxMx. The patient underwent treatment with brachytherapy, reconstruction with a free flap, and subsequently chemotherapy. To the best of our knowledge, this is the first case report of leiomyosarcoma developing in a replanted extremity. Development of leiomyosarcoma in this case could be related to revascularization, scar formation, or chronic injury after replantation. The patient remains healthy without signs of recurrence at three-year follow-up.

  7. Experimental investigation of bond strength under high loading rates

    Science.gov (United States)

    Michal, Mathias; Keuser, Manfred; Solomos, George; Peroni, Marco; Larcher, Martin; Esteban, Beatriz

    2015-09-01

    The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw) and the Joint Research Centre (JRC) in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.

  8. Experimental investigation of bond strength under high loading rates

    Directory of Open Access Journals (Sweden)

    Michal Mathias

    2015-01-01

    Full Text Available The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw and the Joint Research Centre (JRC in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.

  9. Strength calculation for fiber concrete slabs under high velocity impact

    Science.gov (United States)

    Artem, Ustinov; Kopanica, Dmitry; Belov, Nikolay; Jugov, Nikolay; Jugov, Alexey; Koshko, Bogdan; Kopanitsa, Georgy

    2017-01-01

    The paper presents results of the research on strength of concrete slabs reinforced with steel fiber and tested under a high velocity impact. Mathematical models are proposed to describe the behavior of continua with a complex structure with consideration of porosity, non-elastic effects, phase transformations and dynamic destructions of friable and plastic materials under shock wave impact. The models that describe the behavior of structural materials were designed in the RANET-3 CAD software system. This allowed solving the tasks of hit and explosion in the full three-dimensional statement using finite elements method modified for dynamic problems. The research results demonstrate the validity of the proposed mathematical model to calculate stress-strain state and fracture of layered fiber concrete structures under high velocity impact caused by blast wave.

  10. The effect of high speed strength training with heavy and low workloads on neuromuscular function and maximal concentric quadriceps strength.

    Science.gov (United States)

    Mazani, Ali A; Hamedinia, Mohamed R; Haghighi, Amir H; Hedayatpour, Nosratollah

    2018-04-01

    Dynamic strength training has been widely used to increase the ability of skeletal muscle to produce muscle force. Manipulating resistance training program variables has been commonly used as a tool to optimize maximum strength. This study examined the effects of 12 weeks of high-speed strength training with low and heavy workloads on muscle strength and neuromuscular function of quadriceps muscle. Thirty male subjects (age, mean±SD, 20.6±2.6 yr, body mass 70.4±12.9 kg, height 1.76±0.09 m) with no history of knee injury or trauma participated to the study. Subjects were randomly divided into two training groups, low workload training (40% 1RM) and heavy workload training (80% 1RM). One repetition of maximum leg-press measured before and after 12 weeks training. Moreover, surface electromyograpic signals were recorded from vastus medialis and lateralis muscle during one repetition of maximum leg-press before and after 12 weeks training. High speed training with heavy workload-low repetition resulted in a greater increase (41.8%±4.3) in maximal concentric quadriceps strength compared with high speed training with low workloads-high repetition (23.3%±2.7; F=3.8, Ptraining with heavy workload- low repetition was significantly larger than those observed after high speed training with low workload- high repetition (F=5.5, Ptraining, which in turn result in greater improvement in muscle strength.

  11. Design of a low-alloy high-strength and high-toughness martensitic steel

    Science.gov (United States)

    Zhao, Yan-jun; Ren, Xue-ping; Yang, Wen-chao; Zang, Yue

    2013-08-01

    To develop a high strength low alloy (HSLA) steel with high strength and high toughness, a series of martensitic steels were studied through alloying with various elements and thermodynamic simulation. The microstructure and mechanical properties of the designed steel were investigated by optical microscopy, scanning electron microscopy, tensile testing and Charpy impact test. The results show that cementite exists between 500°C and 700°C, M7C3 exits below 720°C, and they are much lower than the austenitizing temperature of the designed steel. Furthermore, the Ti(C,N) precipitate exists until 1280°C, which refines the microstructure and increases the strength and toughness. The optimal alloying components are 0.19% C, 1.19% Si, 2.83% Mn, 1.24% Ni, and 0.049% Ti; the tensile strength and the V notch impact toughness of the designed steel are more than 1500 MPa and 100 J, respectively.

  12. Modeling of Compressive Strength for Self-Consolidating High-Strength Concrete Incorporating Palm Oil Fuel Ash

    Science.gov (United States)

    Safiuddin, Md.; Raman, Sudharshan N.; Abdus Salam, Md.; Jumaat, Mohd. Zamin

    2016-01-01

    Modeling is a very useful method for the performance prediction of concrete. Most of the models available in literature are related to the compressive strength because it is a major mechanical property used in concrete design. Many attempts were taken to develop suitable mathematical models for the prediction of compressive strength of different concretes, but not for self-consolidating high-strength concrete (SCHSC) containing palm oil fuel ash (POFA). The present study has used artificial neural networks (ANN) to predict the compressive strength of SCHSC incorporating POFA. The ANN model has been developed and validated in this research using the mix proportioning and experimental strength data of 20 different SCHSC mixes. Seventy percent (70%) of the data were used to carry out the training of the ANN model. The remaining 30% of the data were used for testing the model. The training of the ANN model was stopped when the root mean square error (RMSE) and the percentage of good patterns was 0.001 and ≈100%, respectively. The predicted compressive strength values obtained from the trained ANN model were much closer to the experimental values of compressive strength. The coefficient of determination (R2) for the relationship between the predicted and experimental compressive strengths was 0.9486, which shows the higher degree of accuracy of the network pattern. Furthermore, the predicted compressive strength was found very close to the experimental compressive strength during the testing process of the ANN model. The absolute and percentage relative errors in the testing process were significantly low with a mean value of 1.74 MPa and 3.13%, respectively, which indicated that the compressive strength of SCHSC including POFA can be efficiently predicted by the ANN. PMID:28773520

  13. Pharmacokinetic MRI of the prostate. Parameters for differentiating low-grade and high-grade prostate cancer

    International Nuclear Information System (INIS)

    Franiel, T.; Taupitz, M.; Asbach, P.; Beyersdorff, D.; Luedemann, L.; Rost, J.

    2009-01-01

    Purpose: to investigate whether pharmacokinetic MRI parameters ''perfusion, blood volume, mean transit time (MTT), interstitial volume, permeability, extraction coefficient, delay, and dispersion'' allow the differentiation of low-grade (Gleason score ≤ 6) and high-grade (Gleason score ≥ 7) prostate cancer. Materials and method: forty-two patients with prostate cancer verified by biopsy (PSA 2.7 to 31.4ng/ml) and scheduled for prostatectomy underwent MRI at 1.5 Tesla using the dynamic contrast-enhanced inversion-prepared dual-contrast gradient echo sequence (temporal resolution, 1.65 s) and a combined endorectal body phased array coil. Parametric maps were computed using a sequential 3-compartment model and the corresponding post-processing algorithms. A total of 41 areas of prostate cancer (15 low-grade, 26 high-grade cancers) in 32 patients were able to be correlated with the prostatectomy specimens and were included in the analysis. Results: low-grade prostate cancers had a higher mean blood volume (1.76% vs. 1.64%, p = 0.039), longer MTT (6.39 s vs. 3.25 s, p -1 vs. 3.86 min -1 , p = 0.011) than high-grade cancers. No statistically significant difference was found for perfusion (p = 0.069), interstitial volume (p = 0.849), extraction coefficient (p = 0.615), delay (p = 0.489), and dispersion (p = 0.306). (orig.)

  14. High grade serous ovarian carcinomas originate in the fallopian tube.

    Science.gov (United States)

    Labidi-Galy, S Intidhar; Papp, Eniko; Hallberg, Dorothy; Niknafs, Noushin; Adleff, Vilmos; Noe, Michael; Bhattacharya, Rohit; Novak, Marian; Jones, Siân; Phallen, Jillian; Hruban, Carolyn A; Hirsch, Michelle S; Lin, Douglas I; Schwartz, Lauren; Maire, Cecile L; Tille, Jean-Christophe; Bowden, Michaela; Ayhan, Ayse; Wood, Laura D; Scharpf, Robert B; Kurman, Robert; Wang, Tian-Li; Shih, Ie-Ming; Karchin, Rachel; Drapkin, Ronny; Velculescu, Victor E

    2017-10-23

    High-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian cancer and has a poor outcome. It has been proposed that fallopian tube cancers may be precursors of HGSOC but evolutionary evidence for this hypothesis has been limited. Here, we perform whole-exome sequence and copy number analyses of laser capture microdissected fallopian tube lesions (p53 signatures, serous tubal intraepithelial carcinomas (STICs), and fallopian tube carcinomas), ovarian cancers, and metastases from nine patients. The majority of tumor-specific alterations in ovarian cancers were present in STICs, including those affecting TP53, BRCA1, BRCA2 or PTEN. Evolutionary analyses reveal that p53 signatures and STICs are precursors of ovarian carcinoma and identify a window of 7 years between development of a STIC and initiation of ovarian carcinoma, with metastases following rapidly thereafter. Our results provide insights into the etiology of ovarian cancer and have implications for prevention, early detection and therapeutic intervention of this disease.

  15. Heap leaching process of high-grade uranium ore

    International Nuclear Information System (INIS)

    Lin Sirong; Gao Xizheng; Guo Erhua; Lu Shijie

    1994-08-01

    A heap leaching process for high-grade primary uranium ore has been studied. The minerals mainly are uraninite. In the process the manganese dioxide is used as oxidant and ferric sulphate solution as leaching agent. The two-stage counter current heap leach method is used in the process. The leached liquor which contains dissolved uranium and iron returns to the neutralizing stage and the iron in the leached liquor is precipitated in the stage. The acid is added to the main stage and the precipitated iron is dissolved as Fe 2 (SO 4 ) 3 in the stage. Comparing with conventional agitation acid leaching method, this process decreases the consumption of acid by 21% and manganese dioxide by 29%. The extraction rate of uranium reduces 1.86%. (3 figs., 12 tabs.)

  16. High Grade Infective Spondylolisthesis of Cervical Spine Secondary to Tuberculosis.

    Science.gov (United States)

    Hadgaonkar, Shailesh; Shah, Kunal; Shyam, Ashok; Sancheti, Parag

    2015-12-01

    Spondylolisthesis coexisting with tuberculosis is rarely reported. There is a controversy whether spondylolisthesis coexists or precedes tuberculosis. Few cases of pathological spondylolisthesis secondary to tuberculous spondylodiscitis have been reported in the lumbar and lumbosacral spine. All cases in the literature presented as anterolisthesis, except one which presented as posterolisthesis of lumbar spine. Spondylolisthesis in the cervical spine is mainly degenerative and traumatic. Spondylolisthesis due to tuberculosis is not reported in the lower cervical spine. The exact mechanism of such an occurrence of spondylolisthesis with tuberculosis is sparsely reported in the literature and inadequately understood. We report a rare case of high grade pathological posterolisthesis of the lower cervical spine due to tubercular spondylodiscitis in a 67-year-old woman managed surgically with a three-year follow-up period. This case highlights the varied and complex presentation of tuberculosis of the lower cervical spine and gives insight into its pathogenesis, diagnosis, and management.

  17. Radio-fluoro guided surgery in high grade gliomas

    International Nuclear Information System (INIS)

    Lopez Piloto, Orestes; Salva Camano, Silvia; Gonzalez Gonzalez, Justo; Cruz Hernandez, Tania Margarita; Martinez Suarez, Eduardo; Lopez Arbolay, Omar; Ardisana Santana, Ernesto

    2015-01-01

    The MIBI (99mTc MIBI, methoxyisobutylisonitrile, MIBI, or sestamibi): is a wide readiness to the rich flow of photons, which improves the detection of pathological uptake with gamma probe, these physical properties make of this radiotracer the election to radioguided surgery. The sodium fluorescein is a water-soluble organic coloring substance used in the exam of the sanguine glasses of the eye. We carried out the report of five cases diagnosed with brain tumor of high grade of malignancy, with the objective to demonstrated that use of Radio-Fluro-guided Surgery (RFGS) we can achieve gross total resections without bigger deficit, completing the inclusion and exclusion criteria. The technique of RFGS demonstrated utility in the gross total resection, diminishing the residual tumor, without increasing surgery complexity and surgical times. In our study doesn't evidence of adverse effects for the administration of the radiopharmaceuticals and fluorescein

  18. High Strength Concrete Columns under Axial Compression Load: Hybrid Confinement Efficiency of High Strength Transverse Reinforcement and Steel Fibers

    Science.gov (United States)

    Perceka, Wisena; Liao, Wen-Cheng; Wang, Yo-de

    2016-01-01

    Addition of steel fibers to high strength concrete (HSC) improves its post-peak behavior and energy absorbing capability, which can be described well in term of toughness. This paper attempts to obtain both analytically and experimentally the efficiency of steel fibers in HSC columns with hybrid confinement of transverse reinforcement and steel fibers. Toughness ratio (TR) to quantify the confinement efficiency of HSC columns with hybrid confinement is proposed through a regression analysis by involving sixty-nine TRs of HSC without steel fibers and twenty-seven TRs of HSC with hybrid of transverse reinforcement and steel fibers. The proposed TR equation was further verified by compression tests of seventeen HSC columns conducted in this study, where twelve specimens were reinforced by high strength rebars in longitudinal and transverse directions. The results show that the efficiency of steel fibers in concrete depends on transverse reinforcement spacing, where the steel fibers are more effective if the spacing transverse reinforcement becomes larger in the range of 0.25–1 effective depth of the section column. Furthermore, the axial load–strain curves were developed by employing finite element software (OpenSees) for simulating the response of the structural system. Comparisons between numerical and experimental axial load–strain curves were carried out. PMID:28773391

  19. Alkali control of high-grade metamorphism and granitization

    Directory of Open Access Journals (Sweden)

    Oleg G. Safonov

    2014-09-01

    Full Text Available We review petrologic observations of reaction textures from high-grade rocks that suggest the passage of fluids with variable alkali activities. Development of these reaction textures is accompanied by regular compositional variations in plagioclase, pyroxenes, biotite, amphibole and garnet. The textures are interpreted in terms of exchange and net-transfer reactions controlled by the K and Na activities in the fluids. On the regional scale, these reactions operate in granitized, charnockitized, syenitized etc. shear zones within high-grade complexes. Thermodynamic calculations in simple chemical systems show that changes in mineral assemblages, including the transition from the hydrous to the anhydrous ones, may occur at constant pressure and temperature due only to variations in the H2O and the alkali activities. A simple procedure for estimating the activity of the two major alkali oxides, K2O and Na2O, is implemented in the TWQ software. Examples of calculations are presented for well-documented dehydration zones from South Africa, southern India, and Sri Lanka. The calculations have revealed two end-member regimes of alkalis during specific metamorphic processes: rock buffered, which is characteristic for the precursor rocks containing two feldspars, and fluid-buffered for the precursor rocks without K-feldspar. The observed reaction textures and the results of thermodynamic modeling are compared with the results of available experimental studies on the interaction of the alkali chloride and carbonate-bearing fluids with metamorphic rocks at mid-crustal conditions. The experiments show the complex effect of alkali activities in the fluid phase on the mineral assemblages. Both thermodynamic calculations and experiments closely reproduce paragenetic relations theoretically predicted by D.S. Korzhinskii in the 1940s.

  20. Leaks in nuclear grade high efficiency aerosol filters

    Energy Technology Data Exchange (ETDEWEB)

    Scripsick, Ronald Clyde [Univ. of California, Davis, CA (United States)

    1994-07-01

    Nuclear grade high efficiency aerosol filters, also known as high efficiency particulate air (HEPA) filters, are commonly used in air cleaning systems for removal of hazardous aerosols. Performance of the filter units is important in assuring health and environmental protection. The filter units are constructed from pleated packs of fiberglass filter media sealed into rigid frames. Results of previous studies on such filter units indicate that their performance may not be completely predicted by ideal performance of the fibrous filter media. In this study, departure from ideal performance is linked to leaks existing in filter units and overall filter unit performance is derived from independent performance of the individual filter unit components. The performance of 14 nuclear grade HEPA filter units (size 1, 25 cfm) with plywood frames was evaluated with a test system that permitted independent determination of penetration as a function of particle size for the whole filter unit, the filter unit frame, and the filter media pack. Tests were performed using a polydisperse aerosol of di-2-ethylhexyl phthalate with a count median diameter of 0.2 {mu}m and geometric standard deviation of 1.6. Flow rate and differential pressure were controlled from 1% to 100% of design values. Particle counts were made upstream and downstream of the filter unit with an optical particle counter (OPC). The OPC provided count information in 28 size channels over the particle diameter range from 0.1 to 0.7 μm. Results provide evidence for a two component leak model of filler unit performance with: (1) external leaks through filter unit frames, and (2) internal leaks through defects in the media and through the seal between the media pack and frame. For the filter units evaluated, these leaks dominate overall filter unit performance over much of the flow rate and particle size ranges tested.

  1. Recent Niobium Developments for High Strength Steel Energy Applications

    Science.gov (United States)

    Jansto, Steven G.

    Niobium-containing high strength steel materials have been developed for oil and gas pipelines, offshore platforms, nuclear plants, boilers and alternative energy applications. Recent research and the commercialization of alternative energy applications such as windtower structural supports and power transmission gear components provide enhanced performance. Through the application of these Nb-bearing steels in demanding energy-related applications, the designer and end user experience improved toughness at low temperature, excellent fatigue resistance and fracture toughness and excellent weldability. These enhancements provide structural engineers the opportunity to further improve the structural design and performance. For example, through the adoption of these Nb-containing structural materials, several design-manufacturing companies are initiating new windtower designs operating at higher energy efficiency, lower cost, and improved overall material design performance.

  2. Quick corrosion cracking test methods for high strength stainless steels

    International Nuclear Information System (INIS)

    Gurnich, L.Ya.; Shubadeeva, L.I.; Erofeeva, V.L.; Lashchevskij, V.B.

    1994-01-01

    Quicks method for testing high strength stainless steels during 10h under atmospheric and sea conditions has been developed. It is shown that (NH 4 ) 2 Se 2 O 8 - 13.5+-1 g/l, NaCl - 40+-2g/l, H 2 SO 4 -5g/l solution at 50+-2 C temperature is recommended for quick tests for tendency to corrosion cracking during. Development of steels and technologies of their treatment. Tests of steels of 08Kh15N5D2T, 07Kh16N6, 20Kh13, 40Kh13, 13Kh15N4AMD and other types can be performed in boiling solutions: H 2 SO 4 (55 ml/l)+CuSO 4 (110 g/l) or MgCl 2 (200 g/l hexahydrate)

  3. Thermal Transport in High-Strength Polymethacrylimide (PMI) Foam Insulations

    Science.gov (United States)

    Qiu, L.; Zheng, X. H.; Zhu, J.; Tang, D. W.; Yang, S. Y.; Hu, A. J.; Wang, L. L.; Li, S. S.

    2015-11-01

    Thermal transport in high-strength polymethacrylimide (PMI) foam insulations is described, with special emphasis on the density and temperature effects on the thermal transport performance. Measurements of the effective thermal conductivity are performed by a freestanding sensor-based 3ω method. A linear relationship between the density and the effective thermal conductivity is observed. Based on the analysis of the foam insulation morphological structures and the corresponding geometrical cell model, the quantitative contribution of the solid conductivity and the gas conductivity as well as the radiative conductivity to the total effective thermal conductivity as a function of the density and temperature is calculated. The agreement between the curves of the results from the developed model and experimental data indicate the model can be used for PMI foam insulating performance optimization.

  4. High strength and low weight hollow carbon fibres

    Science.gov (United States)

    Köhler, T.; Brüll, R.; Pursche, F.; Langgartner, J.; Seide, G.; Gries, T.

    2017-10-01

    Carbon fibres have strengths of 2.5 to 5 GPa in the fibre direction and an elastic modulus of 200 to 500 GPa. Carbon fibres have equal mechanical properties as steel but 20% of the weight. But the material is more expensive than steel. Therefore, they are only used in industry sectors where the benefits legitimate the high costs. The use of hollow rather than solid fibres allows an even lower weight of the components. At the same time, similar mechanical properties are achieved by the circular cross section. Carbon fibres are obtained from polyacrylonitrile fibers (PAN). These can be produced as hollow fibres. As a first step stabilization and carbonization of hollow PAN precursors is investigated to produce hollow carbon fibres.

  5. Fatigue crack Behaviour in a High Strength Tool Steel

    DEFF Research Database (Denmark)

    Højerslev, Christian; Carstensen, Jesper V.; Brøndsted, Povl

    2002-01-01

    The influence of microstructure on fatigue crack initiation and crack growth of a hardened and tempered high speed steel was investigated. The evolution of fatigue cracks was followed in four point bending at room temperature. It was found that a carbide damage zone exists above a threshold load...... value of maximally 80% of the yield strength of the steel. The size of this carbide damage zone increases with increasing load amplitude, and the zone is apparently associated with crack nucleation. On fatigue crack propagation plastic deformation of the matrix occurs in a radius of approximately 4...... microns in front of the fatigue crack tip, which is comparable with the relevant mean free carbide spacing....

  6. High-grade renal injuries are often isolated in sports-related trauma

    OpenAIRE

    Patel, Darshan P.; Redshaw, Jeffrey D.; Breyer, Benjamin N.; Smith, Thomas G.; Erickson, Bradley A.; Majercik, Sarah D.; Gaither, Thomas W.; Craig, James R.; Gardner, Scott; Presson, Angela P.; Zhang, Chong; Hotaling, James M.; Brant, William O.; Myers, Jeremy B.

    2015-01-01

    © 2015 Elsevier Ltd. All rights reserved. Introduction: Most high-grade renal injuries (American Association for Surgery of Trauma (AAST) grades III-V) result from motor vehicle collisions associated with numerous concomitant injuries. Sports-related blunt renal injury tends to have a different mechanism, a solitary blow to the flank. We hypothesized that high-grade renal injury is often isolated in sports-related renal trauma. Material and methods: We identified patients with AAST grades III...

  7. Approaches for springback reduction when forming ultra high-strength sheet metals

    Science.gov (United States)

    Radonjic, R.; Liewald, M.

    2016-11-01

    Nowadays, the automotive industry is challenged constantly by increasing environmental regulations and the continuous enhancement of standards with regard to passenger's safety (NCAP, Part 1). In order to fulfil the aforementioned requirements, the use of ultra high-strength steels in research and industrial applications is of high interest. When forming such materials, the main problem results from the large amount of springback which occurs after the release of the part. This paper shows the applicability of several approaches for the reduction of springback amount by forming of one hat channel shaped component. A novel approach for springack reduction which is based on forming with an alternating blank draw-in is presented as well. In this investigation an ultra high-strength steel of the grade DP 980 was used. The part's measurements were taken at significant cross-sections in order to provide a qualitative comparison between the reference geometry and the part's released shape. The obtained results were analysed and used in order to quantify the success of particular approaches for springback reduction. When taking a curved hat channel shaped component as an example, the results achieved in the investigations showed that it is possible to reduce part shape deviations significantly when using DP 980 as workpiece material.

  8. Influence of steel fibres on the blast response of normal-strength and high-strength reinforced concrete columns

    Science.gov (United States)

    Hammoud, A.; Aoude, H.

    2017-09-01

    This paper examines the influence of steel fibres on the blast performance of normal-strength concrete and high-strength concrete columns. As part of the study, four normal-strength and high-strength concrete columns built with and without steel fibres are tested under simulated blast loads using the shock-tube facility at the University of Ottawa. The specimens include two columns built with plain concrete and two columns built with steel fibre-reinforced concrete. The results show that the addition of steel fibres in reinforced concrete columns leads to important enhancements in blast performance, with improved control of mid-span displacements at equivalent blasts and increased damage tolerance.

  9. Study Of The Wet Multipass Drawing Process Applied On High Strength Thin Steel Wires

    Science.gov (United States)

    Thimont, J.; Felder, E.; Bobadilla, C.; Buessler, P.; Persem, N.; Vaubourg, JP.

    2011-05-01

    Many kinds of high strength thin steel wires are involved in so many applications. Most of the time, these wires are made of a pearlitic steel grade. The current developments mainly concern the wire last drawing operation: after a patenting treatment several reduction passes are performed on a slip-type multipass drawing machine. This paper focuses on modeling this multipass drawing process: a constitutive law based on the wire microstructure evolutions is created, a mechanical study is performed, a set of experiments which enables determining the process friction coefficients is suggested and finally the related analytical model is introduced. This model provides several general results about the process and can be used in order to set the drawing machines.

  10. Behaviour of High Strength Steel Endplate Connections in Fire and after Fire

    NARCIS (Netherlands)

    Qiang, X.

    2013-01-01

    The aim of this research is to reveal more information and understanding on behaviour and failure mechanisms of high strength steel endplate connections (combining high strength steel endplates with either mild steel or high strength steel beams and columns in endplate connections) in fire and after

  11. High bone sialoprotein (BSP expression correlates with increased tumor grade and predicts a poorer prognosis of high-grade glioma patients.

    Directory of Open Access Journals (Sweden)

    Tao Xu

    Full Text Available OBJECTIVES: To investigate the expression and prognostic value of bone sialoprotein (BSP in glioma patients. METHODS: We determined the expression of BSP using real-time RT-PCR and immunohistochemistry in tissue microarrays containing 15 normal brain and 270 glioma samples. Cumulative survival was calculated by the Kaplan-Meier method and analyzed by the log-rank test. Univariate and multivariate analyses were performed by the stepwise forward Cox regression model. RESULTS: Both BSP mRNA and protein levels were significantly elevated in high-grade glioma tissues compared with those of normal brain and low-grade glioma tissues, and BSP expression positively correlated with tumor grade (P<0.001. Univariate and multivariate analysis showed high BSP expression was an independent prognostic factor for a shorter progression-free survival (PFS and overall survival (OS in both grade III and grade IV glioma patients [hazard ratio (HR = 2.549 and 3.154 for grade III glioma, and HR = 1.637 and 1.574 for grade IV glioma, respectively]. Patients with low BSP expression had a significantly longer median OS and PFS than those with high BSP expression. Small extent of resection and lineage of astrocyte served as independent risk factors of both shorter PFS and OS in grade III glioma patients; GBM patients without O(6-methylguanine (O(6-meG DNA methyltransferase (MGMT methylation and Karnofsky performance score (KPS less than 70 points were related to poor prognosis. Lack of radiotherapy related to shorter OS but not affect PFS in both grade III and grade IV glioma patients. CONCLUSION: High BSP expression occurs in a significant subset of high-grade glioma patients and predicts a poorer outcome. The study identifies a potentially useful molecular marker for the categorization and targeted therapy of gliomas.

  12. A Highly Miniaturized Inertial Grade Gyroscope for Space Applications

    Science.gov (United States)

    Wiberg, D. V.; Challoner, A. D.; Shcheglov, K.; Hayworth, K.; Bae, S.; Yee, K.; Blaes, B.; DAgostino, S.; Stock, T.

    2001-01-01

    The evolution of inertial grade gyroscopes for space applications represents well over 50 years of technology development and an investment of hundreds of millions of dollars. The workhorse product which represents the current state-of-the art for commercially available high performance devices is the Litton-Hemishperical Resonator Gyro (HRG) Inertial Measurement Unit (IMU). This product has a performance figure of merit of 0.003 deg/hr bias drift, a volume of 567 cubic inches, weighs 19 pounds, draws about 30 watts and costs over 1 million each. Clearly devices of this magnitude are not conducive to the minimized mass, volume, power, and cost constraints of outer planet missions. An approach to breaking these potential barriers is the use of Microelectromechanical Systems (MEMS) based inertial devices. Although substantially reduced in size, mass power and cost, this approach has produced devices in the tactical performance range of greater than 1 deg/hour bias drift. This level of performance satisfies the preponderance of high market volume requirements such as automotive and tactical munitions but does not meet the limited market quantity requirements for the high precision space based market. Because of the very limited size of the space based market, there is little economic incentive for commercial fabricators of tactical grade devices to address the necessary performance improvements. The Jet Propulsion Laboratory (JPL) in conjunction with Boeing Space Systems (BSS) is addressing this void to satisfy our mutual requirements in this area. The project objective to is to achieve 0.01 deg/hr performance in an IMU which is less than 10 cubic inches in volume, weighs less than 0.5 pounds, draws less than 1 watt and is available in volume production for less than 2500. Reductions of this magnitude will be mission enabling capabilities for a variety of anticipated outer planet mission attributes such as autonomous control and docking, formation flying and robotic

  13. 3D printing of high-strength aluminium alloys

    Science.gov (United States)

    Martin, John H.; Yahata, Brennan D.; Hundley, Jacob M.; Mayer, Justin A.; Schaedler, Tobias A.; Pollock, Tresa M.

    2017-09-01

    Metal-based additive manufacturing, or three-dimensional (3D) printing, is a potentially disruptive technology across multiple industries, including the aerospace, biomedical and automotive industries. Building up metal components layer by layer increases design freedom and manufacturing flexibility, thereby enabling complex geometries, increased product customization and shorter time to market, while eliminating traditional economy-of-scale constraints. However, currently only a few alloys, the most relevant being AlSi10Mg, TiAl6V4, CoCr and Inconel 718, can be reliably printed; the vast majority of the more than 5,500 alloys in use today cannot be additively manufactured because the melting and solidification dynamics during the printing process lead to intolerable microstructures with large columnar grains and periodic cracks. Here we demonstrate that these issues can be resolved by introducing nanoparticles of nucleants that control solidification during additive manufacturing. We selected the nucleants on the basis of crystallographic information and assembled them onto 7075 and 6061 series aluminium alloy powders. After functionalization with the nucleants, we found that these high-strength aluminium alloys, which were previously incompatible with additive manufacturing, could be processed successfully using selective laser melting. Crack-free, equiaxed (that is, with grains roughly equal in length, width and height), fine-grained microstructures were achieved, resulting in material strengths comparable to that of wrought material. Our approach to metal-based additive manufacturing is applicable to a wide range of alloys and can be implemented using a range of additive machines. It thus provides a foundation for broad industrial applicability, including where electron-beam melting or directed-energy-deposition techniques are used instead of selective laser melting, and will enable additive manufacturing of other alloy systems, such as non-weldable nickel

  14. The effect of winter sports participation on high school football players: strength, power, agility, and body composition.

    Science.gov (United States)

    Wroble, R R; Moxley, D R

    2001-02-01

    In this study, football players (N = 57) in grades 9-11 from 3 high schools chose to participate in 1 of 2 groups. Group WC (N = 39) participated in off-season strength training only. Group SP (N = 18) participated in both a winter sport (either wrestling or basketball) and an identical strength training program. All participants were tested at the close of football season (Pre) and at the end of the winter sports season (Post), a period of 4 months. Body composition (weight [W] and body fat percentage [BF]), strength (calculated 1RM [1 repetition maximum] max for barbell bench press [BP] and squat [SQ]), power (vertical jump [VJ] and seated shot put [UP]), and agility (18.3-m agility run [AG]) were measured. Both groups WC and SP increased significantly in W and BF and improved significantly in BP and VJ (p training.

  15. High-strength fiber-reinforced plastic reinforcement of wood and wood composite

    Energy Technology Data Exchange (ETDEWEB)

    Tingley, D.A.; Eng, P. [Oregon State Univ., Corvallis, OR (United States)

    1996-12-31

    Research and development underway since 1982 has led to the development of a method of reinforcing wood and wood composite structural products (WWC) using high-strength fiber-reinforced plastic. This method allows the use of less wood fiber and lower grade wood fiber for a given load capacity. The first WWC in which reinforcement has been marketed is glulam beams. Marketed under the trade name FiRP{trademark} Reinforced glulam, the product has gained code approval and is now being used in the construction of buildings and bridges in the United States, Japan and other countries. The high-strength fiber-reinforced plastic (FiRP{trademark} Reinforced panel (RP)) has specific characteristics that are required to provide for proper use in WWC`s. This paper discusses these characteristics and the testing requirements to develop code approved allowable design values for carbon, aramid and fiberglass RP`s for such uses. Specific issues such as in-service characteristics, i.e. long term creep tests and tension-tension fatigue tests, are discussed.

  16. EXPERIMENTAL STUDY ON THE APPLICATION OF HIGH STRENGTH FIBER REINFORCED MORTAR TO PRESTRESSED CONCRETE STRUCTURES

    Science.gov (United States)

    Sakurada, Michihiro; Mori, Takuya; Ohyama, Hiroaki; Seki, Hiroshi

    In order to study the application of high strength fiber reinforced mortar which has design compressive strength 120N/mm2 to prestressed concrete structures, the authors carried out material tests, bending tests and shear tests of prestressed concrete beam specimens. From the material tests, we obtained material properties for the design of prestressed concrete structures such as compressive strength, tensile strength, Young's modulus, coefficient of creep, dry shrinkage and so on. The results of the bending tests and the shear tests of prestressed concrete beam specimen shows that experimental flexural strength and shear strength of prestressed concrete beam using high strength fiber reinforced mortar exceeds strength calculated by traditional design method. It is confirmed that high strength fiber reinforced mortar can be applied to prestressed concrete structures.

  17. Effect of pulsed current welding on fatigue behaviour of high strength aluminium alloy joints

    International Nuclear Information System (INIS)

    Balasubramanian, V.; Ravisankar, V.; Madhusudhan Reddy, G.

    2008-01-01

    High strength aluminium alloys (Al-Zn-Mg-Cu alloys) have gathered wide acceptance in the fabrication of light weight structures requiring high strength-to weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due to their comparatively easier applicability and better economy. Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results inferior weld mechanical properties and poor resistance to hot cracking. In this investigation, an attempt has been made to refine the fusion zone grains by applying pulsed current welding technique. Rolled plates of 6 mm thickness have been used as the base material for preparing single pass welded joints. Single V butt joint configuration has been prepared for joining the plates. The filler metal used for joining the plates is AA 5356 (Al-5Mg (wt%)) grade aluminium alloy. Four different welding techniques have been used to fabricate the joints and they are: (i) continuous current GTAW (CCGTAW), (ii) pulsed current GTAW (PCGTAW), (iii) continuous current GMAW (CCGMAW) and (iv) pulsed current GMAW (PCGMAW) processes. Argon (99.99% pure) has been used as the shielding gas. Fatigue properties of the welded joints have been evaluated by conducting fatigue test using rotary bending fatigue testing machine. Current pulsing leads to relatively finer and more equi-axed grain structure in gas tungsten arc (GTA) and gas metal arc (GMA) welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain structures. Grain refinement is accompanied by an increase in fatigue life and endurance limit

  18. Research and Development of Ultra-High Strength X100 Welded Pipe

    Science.gov (United States)

    Chuanguo, Zhang; Lei, Zheng; Ping, Hu; Bei, Zhang; Kougen, Wu; Weifeng, Huang

    Ultra-high strength X100 welded pipe can be used in the construction of long distance oil and gas pipeline to improve transmission capacity and reduce operation cost. By using the way of thermo-simulation and pilot rolling, the CCT (Continuous Cooling Transformation) diagram and the relationship between ACC (Accelerated Cooling) parameters, microstructure and mechanical properties were studied for the designed X100 pipeline steel with low carbon, high manganese and niobium micro-alloyed composition in lab. The analysis of CCT diagram indicates that the suitable hardness and microstructure can be obtained in the cooling rate of 20 80°C/sec. The pilot rolling results show that the ACC cooling start temperature below Ar3 phase transformation point is beneficial to increase uniform elongation, and the cooling stop temperature of 150 350°C is helpful to obtain high strength and toughness combination. Based on the research conclusions, the X100 plate and UOE pipe with dimension in O.D.1219×W.T.14.8mm, O.D.1219×W.T.17.8mm, designed for the natural gas transmission pipeline, were trial produced. The manufactured pipe body impact absorbed energy at -10°C is over 250J. The DWTT shear area ratio at 0°C is over 85%. The transverse strength meets the X100 grade requirement, and uniform elongation is over 4%. The X100 plate and UOE pipe with dimension in O.D.711×W.T.20.0mm, O.D.711×W.T.12.5mm, designed for an offshore engineering, were also trial produced. The average impact absorbed energy of pipe body at -30°C is over 200J. The average impact absorbed energy of HAZ (Heat-affected zone) and WM (Welded Seam) at -30°C is over 100J. And the good pipe shapes were obtained

  19. Technical Note: Filler and superplasticizer usage on high strength concrete

    Directory of Open Access Journals (Sweden)

    Sümer, M.

    2007-08-01

    Full Text Available In this research, the effects of filler (rock-dust usage on high strength concrete have been investigated through lab experiments and some results have been obtained. The experiments involved three series of concrete with different cement proportions of 375 kg/m3, 400 kg/m3, and 425 kg/m3. For each series of concrete, three different groups of samples have been prepared, the first one being the reference concrete which contained 0% chemical admixture and 0% filler, the second one contained 1.5% chemical admixture and 0% filler and finally the last group contained 1.5% chemical admixture and 5% filler to the weight of cement used. The chemical admixture used was a type of Super plasticizer with a brand name of “DARACEM 190”, and the cement used was Ordinary Portland Cement of target compressive strength 42.5 N/mm2, obtained from Nuh Cement Plant. For each batch, Slump Tests and Unit Weight Tests were performed. For each stage and group, two 15 cm cubic samples have been tested for Compressive Strength after being cured in water at 20 ± 2 °C for ages of 3 days, 7 days, 28 and 60 days. The total number of samples was 72. As a result, filler usage was found to reduce the porosity of Concrete, increase the Unit Weight of Concrete, increase the need for water and improve the Compressive Strength Properties of Concrete.En el presente trabajo se estudia la influencia de la utilización de un “filler” (polvo mineral en el comportamiento del hormigón de altas prestaciones. Para ello, se realizan ensayos de laboratorio en los que se emplean tres series de hormigón, cada una con una dosificación de cemento distinta, de 375, 400 y 425 kg/m3. Se preparan tres grupos de probetas de cada serie, el primero o de referencia con 0% de aditivo químico y 0% de “filler”, el segundo con un 1,5% del aditivo químico y 0% de “filler” y el tercero con un 1,5% del aditivo químico y un 5% de “filler” en peso del cemento. Como aditivo se

  20. High bonding temperatures greatly improve soy adhesive wet strength

    Science.gov (United States)

    Charles R. Frihart; Thomas Coolidge; Chera Mock; Eder Valle

    2016-01-01

    Soy wood adhesive bond strengths reported in different literature studies are difficult to compare because a variety of temperatures and other conditions have been used for the bonding and testing step. Some reports have indicated bond strengths are sensitive to bonding temperature, but the reason(s) for this has not been intensively investigated. Although these prior...

  1. Wear Behavior of an Ultra-High-Strength Eutectoid Steel

    Science.gov (United States)

    Mishra, Alok; Maity, Joydeep

    2018-02-01

    Wear behavior of an ultra-high-strength AISI 1080 steel developed through incomplete austenitization-based combined cyclic heat treatment is investigated in comparison with annealed and conventional hardened and tempered conditions against an alumina disk (sliding speed = 1 m s-1) using a pin-on-disk tribometer at a load range of 7.35-14.7 N. On a gross scale, the mechanism of surface damage involves adhesive wear coupled with abrasive wear (microcutting effects in particular) at lower loads. At higher loads, mainly the abrasive wear (both microcutting and microploughing mechanisms) and evolution of adherent oxide are observed. Besides, microhardness of matrix increases with load indicating substantial strain hardening during wear test. The rate of overall wear is found to increase with load. As-received annealed steel with the lowest initial hardness suffers from severe abrasive wear, thereby exhibiting the highest wear loss. Such a severe wear loss is not observed in conventional hardened and tempered and combined cyclic heat treatment conditions. Combined cyclic heat-treated steel exhibits the greatest wear resistance (lowest wear loss) due to its initial high hardness and evolution of hard abrasion-resistant tribolayer during wear test at higher load.

  2. Prognostic service life assessment of high-strength metallic materials in high temperature environments

    International Nuclear Information System (INIS)

    Danzer, R.

    1988-01-01

    The empirical and theoretical methods for the prediction of service life of high-strength materials are presented. The major mechanisms of failure of metals in high temperatures are given, which include creep and fatigue. The microstructural mechanism of fracture are described, and fracture mechanics methods of analysis and evaluation are explained. (orig./MM) With 92 figs., 6 tabs [de

  3. Concurrent thermochemoradiotherapy for brain high-grade glioma

    Energy Technology Data Exchange (ETDEWEB)

    Ryabova, A. I., E-mail: ranigor@mail.ru; Novikov, V. A.; Startseva, Zh. A.; Bober, E. E.; Frolova, I. G. [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); Choinzonov, E. L. [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); Siberian State Medical University, Tomsk, 634050 (Russian Federation); Gribova, O. V. [Tomsk Cancer Research Institute, Tomsk, 634050 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Baranova, A. V. [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2016-08-02

    Despite the achievements in the current strategies for treatment, the prognosis in malignant glioma patients remains unsatisfactory. Hyperthermia is currently considered to be the most effective and universal modifier of radiotherapy and chemotherapy. Preliminary treatment outcomes for 28 patients with newly diagnosed (23) and recurrent (5) high-grade gliomas were presented. All the patients received multimodality treatment including surgery, thermoche-moradiotherapy followed by 4 cycles of adjuvant chemotherapy. All the patients endured thermochemoradiotherapy well. A complication, limited skin burn (II stage), was diagnosed in two cases and treated conservatively without treatment interruption. A month after thermochemoradiotherapy the results were as follows: complete regression was achieved in 4 cases, partial regression in 4 cases, stable disease in 14 cases and disease progression in 6 cases (one of them is pseudo-progression). After completing the adjuvant chemotherapy 2 more patients demonstrated complete response and 1 patient had disease progression. Introduction of local hyperthermia in multimodal therapy of malignant glioma does not impair the combined modality treatment tolerability of patients with malignant gliomas. A small number of studied patients and short follow-up time do not allow making reliable conclusions about the impact of local hyperthermia on the treatment outcomes; however, there is a tendency towards the increase in disease-free survival in the patients with newly diagnosed malignant gliomas.

  4. Concurrent thermochemoradiotherapy for brain high-grade glioma

    Science.gov (United States)

    Ryabova, A. I.; Novikov, V. A.; Choinzonov, E. L.; Gribova, O. V.; Startseva, Zh. A.; Bober, E. E.; Frolova, I. G.; Baranova, A. V.

    2016-08-01

    Despite the achievements in the current strategies for treatment, the prognosis in malignant glioma patients remains unsatisfactory. Hyperthermia is currently considered to be the most effective and universal modifier of radiotherapy and chemotherapy. Preliminary treatment outcomes for 28 patients with newly diagnosed (23) and recurrent (5) high-grade gliomas were presented. All the patients received multimodality treatment including surgery, thermoche-moradiotherapy followed by 4 cycles of adjuvant chemotherapy. All the patients endured thermochemoradiotherapy well. A complication, limited skin burn (II stage), was diagnosed in two cases and treated conservatively without treatment interruption. A month after thermochemoradiotherapy the results were as follows: complete regression was achieved in 4 cases, partial regression in 4 cases, stable disease in 14 cases and disease progression in 6 cases (one of them is pseudo-progression). After completing the adjuvant chemotherapy 2 more patients demonstrated complete response and 1 patient had disease progression. Introduction of local hyperthermia in multimodal therapy of malignant glioma does not impair the combined modality treatment tolerability of patients with malignant gliomas. A small number of studied patients and short follow-up time do not allow making reliable conclusions about the impact of local hyperthermia on the treatment outcomes; however, there is a tendency towards the increase in disease-free survival in the patients with newly diagnosed malignant gliomas.

  5. Long-term strength and allowable stresses of grade 10Kh9MFB and X10CrMoVNb9-1 (T91/P91) chromium heat-resistant steels

    Science.gov (United States)

    Skorobogatykh, V. N.; Danyushevskiy, I. A.; Schenkova, I. A.; Prudnikov, D. A.

    2015-04-01

    Currently, grade X10CrMoVNb9-1 (T91, P91) and 10Kh9MFB (10Kh9MFB-Sh) chromium steels are widely applied in equipment manufacturing for thermal power plants in Russia and abroad. Compilation and comparison of tensile, impact, and long-term strength tests results accumulated for many years of investigations of foreign grade X10CrMoVNb9-1, T91, P91, and domestic grade 10Kh9MFB (10Kh9MFB-Sh) steels is carried out. The property identity of metals investigated is established. High strength and plastic properties of steels, from which pipes and other products are made, for operation under creep conditions are confirmed. Design characteristics of long-term strength on the basis of tests with more than one million of hour-samples are determined ( and at temperatures of 500-650°C). The table of recommended allowable stresses for grade 10Kh9MFB, 10Kh9MFB-SH, X10CrMoVNb9-1, T91, and P91 steels is developed. The long-time properties of pipe welded joints of grade 10Kh9MFB+10Kh9MFB, 10Kh9MFB-Sh+10Kh9MFB-Sh, X10CrMoVNb9-1+X10CrMoVNb9-1, P91+P91, T91+T91, 10Kh9MFB (10Kh9MFB-Sh)+X10CrMoVNb9-1(T/P91) steels is researched. The welded joint reduction factor is experimentally determined.

  6. The use of radiation for the production of high melt strength polypropylene

    International Nuclear Information System (INIS)

    Lugao, A.B.; Cardoso, E.C.L.; Hustzler, B.; Tokumoto, S.; Mendes, A.N.F.

    2001-01-01

    PP suffers from low melt strength, i.e., the melted PP does not exhibits an increase in resistance to stretching during elongation. It is well known that the melt-strength properties of a polymer increase with molecular weight and with long chain branching due to the increase in the entanglement level (high melt strength PP-HMSPP). In spite of been the most fast growing polymeric commodity nowadays those new grades of PP and its development have been barely studied and its general chemical characterization have been even less studied with few exceptions. HMSPP as proposed by Montell patents are produced by low temperature and low dose irradiation of high molecular weight isotatica PP in N 2 atmosphere. So the well-known reactions would be mostly degradation and crosslinking. Degradation however is supposed to be the first and more intense reaction a the initial steps as already shown. So, according to Montell patents, another reaction is likely to occur, branching or T links competing with crosslinkings or H links. Radical are likely to decay very fast in amorphous phase, but under annealing the radicals entrapped in the crystal phase is likely to move to the boundary and react. The group of professor Silverman has already hypothesized in T links formation and also studied the radical decay of PP. It is easy to understand the difficulties in differentiate Hs from Ts links and even these links if in very small amount from the bulk or from virgin polymer, as the Ts links and even these links if in very small amount from the bulk or from virgin polymer, as the chemical groups and links are chemically speaking essentially the same

  7. High-Performance Slab-on-Grade Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

    2015-09-01

    A more accurate assessment of slab-on-grade foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated).

  8. Anomolous Fatigue Crack Growth Phenomena in High-Strength Steel

    Science.gov (United States)

    Forth, Scott C.; James, Mark A.; Johnston, William M., Jr.; Newman, James C., Jr.

    2004-01-01

    The growth of a fatigue crack through a material is the result of a complex interaction between the applied loading, component geometry, three-dimensional constraint, load history, environment, material microstructure and several other factors. Previous studies have developed experimental and computational methods to relate the fatigue crack growth rate to many of the above conditions, with the intent of discovering some fundamental material response, i.e. crack growth rate as a function of something. Currently, the technical community uses the stress intensity factor solution as a simplistic means to relate fatigue crack growth rate to loading, geometry and all other variables. The stress intensity factor solution is a very simple linear-elastic representation of the continuum mechanics portion of crack growth. In this paper, the authors present fatigue crack growth rate data for two different high strength steel alloys generated using standard methods. The steels exhibit behaviour that appears unexplainable, compared to an aluminium alloy presented as a baseline for comparison, using the stress intensity factor solution.

  9. High-strength cellular ceramic composites with 3D microarchitecture.

    Science.gov (United States)

    Bauer, Jens; Hengsbach, Stefan; Tesari, Iwiza; Schwaiger, Ruth; Kraft, Oliver

    2014-02-18

    To enhance the strength-to-weight ratio of a material, one may try to either improve the strength or lower the density, or both. The lightest solid materials have a density in the range of 1,000 kg/m(3); only cellular materials, such as technical foams, can reach considerably lower values. However, compared with corresponding bulk materials, their specific strength generally is significantly lower. Cellular topologies may be divided into bending- and stretching-dominated ones. Technical foams are structured randomly and behave in a bending-dominated way, which is less weight efficient, with respect to strength, than stretching-dominated behavior, such as in regular braced frameworks. Cancellous bone and other natural cellular solids have an optimized architecture. Their basic material is structured hierarchically and consists of nanometer-size elements, providing a benefit from size effects in the material strength. Designing cellular materials with a specific microarchitecture would allow one to exploit the structural advantages of stretching-dominated constructions as well as size-dependent strengthening effects. In this paper, we demonstrate that such materials may be fabricated. Applying 3D laser lithography, we produced and characterized micro-truss and -shell structures made from alumina-polymer composite. Size-dependent strengthening of alumina shells has been observed, particularly when applied with a characteristic thickness below 100 nm. The presented artificial cellular materials reach compressive strengths up to 280 MPa with densities well below 1,000 kg/m(3).

  10. The Statistical Analysis of Relation between Compressive and Tensile/Flexural Strength of High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Kępniak M.

    2016-12-01

    Full Text Available This paper addresses the tensile and flexural strength of HPC (high performance concrete. The aim of the paper is to analyse the efficiency of models proposed in different codes. In particular, three design procedures from: the ACI 318 [1], Eurocode 2 [2] and the Model Code 2010 [3] are considered. The associations between design tensile strength of concrete obtained from these three codes and compressive strength are compared with experimental results of tensile strength and flexural strength by statistical tools. Experimental results of tensile strength were obtained in the splitting test. Based on this comparison, conclusions are drawn according to the fit between the design methods and the test data. The comparison shows that tensile strength and flexural strength of HPC depend on more influential factors and not only compressive strength.

  11. Preserved splenic function after angioembolisation of high grade injury.

    Science.gov (United States)

    Skattum, Jorunn; Titze, Thomas Larsen; Dormagen, Johann Baptist; Aaberge, Ingeborg S; Bechensteen, Anne Grete; Gaarder, Per Ivar; Gaarder, Christine; Heier, Hans Erik; Næss, Pål Aksel

    2012-01-01

    After introducing splenic artery embolisation (SAE) in the institutional treatment protocol for splenic injury, we wanted to evaluate the effects of SAE on splenic function and assess the need for immunisation in SAE treated patients. 15 SAE patients and 14 splenectomised (SPL) patients were included and 29 healthy blood donors volunteered as controls. Clinical examination, medical history, general blood counts, immunoglobulin quantifications and flowcytometric analysis of lymphocyte phenotypes were performed. Peripheral blood smears from all patients and controls were examined for Howell-Jolly (H-J) bodies. Abdominal doppler, gray scale and contrast enhanced ultrasound (CEUS) were performed on all the SAE patients. Leukocyte and platelet counts were elevated in both SAE and SPL individuals compared to controls. The proportion of memory B-lymphocytes did not differ significantly from controls in either group. In the SAE group total IgA, IgM and IgG levels as well as pneumococcal serotype specific IgG and IgM antibody levels did not differ from the control group. In the SPL group total IgA and IgG Pneumovax(®) (PPV23) antibody levels were significantly increased, and 5 of 12 pneumococcal serotype specific IgGs and IgMs were significantly elevated. H-J bodies were only detected in the SPL group. CEUS confirmed normal sized and well perfused spleens in all SAE patients. In our study non-operative management (NOM) of high grade splenic injuries including SAE, was followed by an increase in total leukocyte and platelet counts. Normal levels of immunoglobulins and memory B cells, absence of H-J bodies and preserved splenic size and intraparenchymal blood flow suggest that SAE has only minor impact on splenic function and that immunisation probably is unnecessary. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Primary balloon angioplasty for symptomatic, high-grade intracranial stenosis.

    Science.gov (United States)

    Tomycz, Luke; Bansal, Neil K; Lockney, Tim; Strothers, Megan; Connors, John J; Shay, Scott; Singer, Robert J

    2013-01-01

    In light of recent controversy about the safety and efficacy of intracranial stenting, we sought to evaluate our experience with primary balloon angioplasty for symptomatic, high-grade intracranial stenosis. All intracranial angioplasty cases performed at Vanderbilt University Medical Center from 2006 to 2011 were retrospectively reviewed for degree of stenosis pre- and post-procedure. Immediate peri-procedural complications were evaluated as well as one-month and long-term outcomes. A total of 26 patients were included in the study with a mean age of 63.0 years and a mean follow-up of 350.2 days. The average pre-procedure stenosis was 71.2%. The immediate, average post-procedure stenosis was 46.6%, and the average post-procedure stenosis at last angiographic follow-up was 44.5%. Retreatment was required in only 3.8% of patients. The primary end-point of major stroke or death at 30 days was observed in 11.5%, and the overall intra-procedural complication rate was 7.7%. The incidence of stroke or death at last follow-up was 15.4%, which is comparable to the one-year stroke or death rate in the medical arm of the SAMPRISS trial. In this retrospective series, primary balloon angioplasty was found to be effective as a treatment option for symptomatic intracranial stenosis with the risk of stroke or death at 30 days higher than the medical arm of SAMPRIS but lower than the stenting arm. The one-year risk of stroke was comparable to that reported for the one-year outcomes in the SAMPRISS medical arm.

  13. TRP 9904 - Constitutive Behavior of High Strength Multiphase Sheel Steel Under High Strain Rate Deformation

    Energy Technology Data Exchange (ETDEWEB)

    David Matlock; John Speer

    2005-03-31

    The focus of the research project was to systematically assess the strain rate dependence of strengthening mechanisms in new advanced high strength sheet steels. Data were obtained on specially designed and produced Duel Phase and TRIP steels and compared to the properties of automotive steels currently in use.

  14. Properties of normal- and high-strength concrete containing metakaolin

    Energy Technology Data Exchange (ETDEWEB)

    Balaguru, P. [Rutgers State Univ. of New Jersey, NJ (United States)

    2001-07-01

    A study was conducted which confirmed the findings of an earlier study that showed that the addition of metakaolin in concrete can improve the compressive strength of concrete and reduce its permeability. Metakaolin is made by calcining purified kaolinite at a specific temperature range. It combines with calcium hydroxide to form calcium silicate and calcium aluminate hydrates. The main objective of this study was to examine the influence of 5 and 9 per cent of metakaolin on plastic and hardened concrete properties. The independent variables were the size of the compressive strength, the type of cement, type of curing and the age at the time of testing. The specimens were cured at 100 per cent relative humidity at 22 degrees C or in warm water maintained at 50 degrees C. The response variables were slump, unit weight, air content, and concrete temperature for fresh concrete. Other variables were compressive strength, modulus of elasticity, modulus of rupture and rapid chloride permeability for hardened concrete. It was shown that air content and curing temperature was not affected by metakaolin, and the effect on unit weight was negligible. Metakaolin was found to improve early compressive strength and also improved the strength at later ages. It also enhances the modulus of elasticity and has little effect on modulus rupture. Control concretes had a low chloride ion permeability. Metakaolin reduced the permeability even further. 8 refs., 11 tabs., 7 figs.

  15. Compression specific toughness of normal strength steel fiber reinforced concrete (NSSFRC) and high strength steel fiber reinforced concrete (HSSFRC)

    OpenAIRE

    Marara,Khaled; Erenb,Özgür; Yitmena,İbrahim

    2011-01-01

    Compression toughness tests were carried out on concrete cylinders reinforced with three different aspect ratios of hooked-end steel fibers 60, 75, and 83 and six different percentages of steel fibers 0.5, 1.0, 1.25, 1.5, 1.75, and 2.0% by volume of concrete. The w/c ratio used for the normal strength steel fiber reinforced concrete mixes (NSSFRC) was 0.55, and the water-cementitious ratio (w/c+s) for the high strength fiber reinforced concrete mixes (HSSFRC) was 0.31. For each mix, three tes...

  16. Optimization of microstructure and properties of high strength spring steel

    NARCIS (Netherlands)

    Choi, S.

    2011-01-01

    This thesis describes a research project on the development of a new grade of low cost spring steel with exceptional mechanical properties on the basis of a complete understanding and quantification of the metallurgical processes taking place during the various stages of the heat treatment. The new

  17. Ultrafine Structure and High Strength in Cold-Rolled Martensite

    DEFF Research Database (Denmark)

    Huang, Xiaoxu; Morito, S.; Hansen, Niels

    2012-01-01

    with a coarse grain size (120 mu m) has also included based on a previous study. Deformation microstructures and structural parameters have been analyzed by transmission electron microscopy and electron backscatter diffraction, and mechanical properties have been characterized by hardness and tensile testing....... At low to medium strains, lath martensite transforms into a cell block structure composed of cell block boundaries and cell boundaries with only a negligible change in strength. At medium to large strains, cell block structures in all samples refine with increasing strain and the hardening rate...... is constant (stage IV). A strong effect of the initial structure is observed on both the structural refinement and the strength increase. This effect is largest in lath martensite and smallest in unalloyed ferrite. No saturation in structural refinement and strength is observed. The discussion covers...

  18. Influence of the welding process on martensitic high strength steel

    Directory of Open Access Journals (Sweden)

    Petr Hanus

    2014-07-01

    Full Text Available The subject of the study is martensitic 22MnB5 steels, which are used in the automotive industry. The main purpose of the performed analyses is a study of strength differences in heat affected zones of the spot welding. For the needs of the strength decrease assessment, the critical layer of the heat affected area was experimentally simulated. The aim of the work is to determine the most suitable methodology for evaluating the local changes of the elastic-plastic material response. The aim of this work is to determine the optimal methods for the determination of the yield strength and to find a firming trend in these zones.

  19. International Differences in Treatment and Clinical Outcomes for High Grade Glioma

    OpenAIRE

    Chien, Li-Nien; Ostrom, Quinn T.; Gittleman, Haley; Lin, Jia-Wei; Sloan, Andrew E.; Barnett, Gene H.; Elder, J. Bradley; McPherson, Christopher; Warnick, Ronald; Chiang, Yung-Hsiao; Lin, Chieh-Min; Rogers, Lisa R.; Chiou, Hung-Yi; Barnholtz-Sloan, Jill S.

    2015-01-01

    Background High grade gliomas are the most common type of malignant brain tumor, and despite their rarity, cause significant morbidity and mortality. This study aimed to compare the treatment patterns of high grade glioma to examine survival patterns in patients who receive specific treatments between cohorts in Ohio and Taiwan. Method Patients aged 18 years and older at age of diagnosis with World Health Organization (WHO) grade III or IV astrocytoma from 2007-2012 were selected from the Ohi...

  20. Yield strength of molybdenum, tantalum and tungsten at high strain rates and very high temperatures

    International Nuclear Information System (INIS)

    Škoro, G.P.; Bennett, J.R.J.; Edgecock, T.R.; Booth, C.N.

    2012-01-01

    Highlights: ► New experimental data on the yield strength of molybdenum, tantalum and tungsten. ► High strain rate effects at record high temperatures (up to 2700 K). ► Test of the consistency of the Zerilli–Armstrong model at very high temperatures. - Abstract: Recently reported results of the high strain rate, high temperature measurements of the yield strength of tantalum and tungsten have been analyzed along with new experimental results on the yield strength of molybdenum. Thin wires are subjected to high stress by passing a short, fast, high current pulse through a thin wire; the amplitude of the current governs the stress and the repetition rate of the pulses determines the temperature of the wire. The highest temperatures reached in the experiments were 2100 °C (for molybdenum), 2250 °C (for tantalum) and 2450 °C (for tungsten). The strain-rates in the tests were in the range from 500 to 1500 s −1 . The parameters for the constitutive equation developed by Zerilli and Armstrong have been determined from the experimental data and the results have been compared with the data obtained at lower temperatures. An exceptionally good fit is obtained for the deformation of tungsten.

  1. Improvement of cross-tension strength using concave electrode in resistance spot welding of high-strength steel sheets

    Science.gov (United States)

    Watanabe, Goro; Amago, Tatsuyuki; Ishii, Yasuhiro; Takao, Hisaaki; Yasui, Toshiaki; Fukumoto, Masahiro

    2016-02-01

    In the spot welding of ultrahigh-strength steel sheets, the generation of expulsion could be suppressed and large-diameter nuggets could be formed by using a concave electrode. The expulsion was suppressed because the clearance for expansion was formed when using the concave electrode. Thus, nuggets with a diameter of ≥4√t (lowest for securing joint strength, t = 1 mm) were obtained without expulsion in a greater welding current range than the range when using a conventional electrode. Furthermore, nuggets with a diameter of approximately 6.5 mm were formed with a large current of 8 kA, which could not be set when using the conventional electrode. In addition, a transition from partial interfacial fracture to pullout fracture occurred as the nugget diameter increased, and the cross-tension strength (CTS) tended to increase. A value of about 8 kN was obtained for a nugget with a diameter of 6.5 mm, which is approximately 1.5 times larger than the value (approximately 5.5 kN) obtained with the conventional electrode. The electrode life test indicated little deterioration in the CTS after 1400 welds. Thus, we propose using a concave electrode to improve the joint strength in the spot welding of high-strength steel sheets.

  2. Geckolike high shear strength by carbon nanotube fiber adhesives

    Science.gov (United States)

    Maeno, Y.; Nakayama, Y.

    2009-01-01

    Carbon nanotube adhesives can adhere strongly to surfaces as a gecko does. The number of carbon nanotube layers is an important determinant of the contact area for adhesion. Balancing the catalyst ratio and buffer layer used for chemical vapor deposition processing controls the number of carbon nanotube layers and their distribution. The features of carbon nanotubes determine the shear strength of adhesion. Carbon nanotubes with a broad distribution of layers exhibit enhanced shear strength with equivalent adhesive capability to that of a natural Tokay Gecko (Gekko gecko)

  3. High breakdown-strength composites from liquid silicone rubbers

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Zakaria, Shamsul Bin; Yu, Liyun

    2014-01-01

    available fillers (an anatase TiO2, a core–shell TiO2-SiO2 and a CaCu3Ti4O12 filler) are evaluated with respect to dielectric permittivity, elasticity (Young’s modulus) and electrical breakdown strength. Film formation properties are also evaluated. The best-performing formulations are those with anatase Ti......O2 nanoparticles, where the highest relative dielectric permittivity of 5.6 is obtained, and with STX801, a core–shell morphology TiO2-SiO2 filler from Evonik, where the highest breakdown strength of 173 V μm−1 is obtained....

  4. Hip strength and knee pain in high school runners: a prospective study.

    Science.gov (United States)

    Finnoff, Jonathan T; Hall, Mederic M; Kyle, Kelli; Krause, David A; Lai, Jim; Smith, Jay

    2011-09-01

    To determine whether pre-injury hip muscle weakness is associated with the development of patellofemoral pain (PFP) in high school running athletes. Prospective cohort study. Academic institution sports medicine center. High school running athletes. Baseline hip strength of high school running athletes was assessed at the beginning of the running season. Strength testing was repeated in athletes who developed PFP. Peak hip muscle strengths and strength ratios were compared between the injured and non-injured groups. Six injuries occurred in 5 of the 98 subjects who completed the study. The baseline hip external-to-internal strength ratio was lower in injured than in uninjured subjects (P = .008). In the injured group, hip abduction and external rotation strengths decreased from pre-injury to post-injury (P = .002 and P = .01, respectively). Logistic regression analysis demonstrated that a greater baseline hip abduction strength (odds ratio = 5.35, 95% confidence interval [CI] 1.46-19.53; P strength ratio increased the risk of injury (odds ratio = 14.14, 95% CI 0.90-221.06; P = .05), and a greater pre-injury hip external-to-internal rotation strength ratio decreased the risk of injury (odds ratio strength when compared with their pre-injury strength. Finally, a higher hip external-to-internal rotation strength ratio may protect against the development of PFP. Copyright © 2011 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  5. Effect of Quadriceps Muscle Strengthening Exercise on Quadriceps and Hamstring Muscle Strength Ratio in Patients with Osteoarthritis Grade 2 and 3

    Directory of Open Access Journals (Sweden)

    Thomas Sintong Pratama Purba

    2017-09-01

    Full Text Available Objective: To evaluate the effect of quadriceps muscle strengthening exercise on quadriceps and hamstring strength ratio in knee osteoarthritis (OA. Methods: This was a quantitative study with quasi-experimental design. The subjects in the study were 16 female patients with knee OA grade 2 and 3. Quadriceps muscle strengthening exercise was given to the subjects 3 times a week during 8 weeks. The study was conducted at the Department of Physical Medicine and Rehabilitation of the Faculty of Medicine, Universitas Padjadjaran-Dr. Hasan Sadikin General Hospital in August–September 2015. Results: It was revealed that the quadriceps muscles improved significantly. However, the hamstring muscles did not show significant improvement based on the comparison between before and after performing the exercise. The average right quadriceps muscle strength before exercise was 12.46 and after exercise was 18. The average left quadriceps muscle strength before and after exercise were 11.59 and 17.7, respectively. The average right hamstring muscle strength before and after exercise were 7.29 and 7.94, respectively. Conclusions: There are quadriceps muscle strength improvements after practicing quadriceps muscle strengthening exercise. However, no significant hamstring muscle strength improvement is seen after practicing quadriceps muscle strengthening exercise. An improvement in quadriceps and hamstring muscle ratio is observed.

  6. Influence of curing regimes on compressive strength of ultra high ...

    Indian Academy of Sciences (India)

    The Association Française de Génie Civil (AFGC) in its interim recommendations states UHPC to have ... participation of all materials in pozzolanic reaction. .... Influence of curing regimes on compressive strength of UHPC. 1425. Table 3. Mix proportion of mix A and mix B. Materials. C. SF. Q. QC. QF. ES-1. ES-3. W/C. SP.

  7. Shear in high strength concrete bridge girders : technical report.

    Science.gov (United States)

    2013-04-01

    Prestressed Concrete (PC) I-girders are used extensively as the primary superstructure components in Texas highway bridges. : A simple semi-empirical equation was developed at the University of Houston (UH) to predict the shear strength of PC I-girde...

  8. Application and Prospects of High-strength Lightweight Materials used in Coal mine

    Science.gov (United States)

    He, Pan

    2017-09-01

    This paper describes some high-strength lightweight materials used in coal mine, and if their performance can meet the requirements of underground safety for explosion-proof, anti-static, friction sparks mine; and reviewed the species, characteristic, preparation process of high-strength lightweight materials for having inspired lightweight high-strength performance by modifying or changing the synthesis mode used in coal mine equipment.

  9. High-strength and high-RRR Al-Ni alloy for aluminum-stabilized superconductor

    CERN Document Server

    Wada, K; Sakamoto, H; Yamamoto, A; Makida, Y

    2000-01-01

    The precipitation type aluminum alloys have excellent performance as the increasing rate in electric resistivity with additives in the precipitation state is considerably low, compared to that of the aluminum alloy with additives in the solid-solution state. It is possible to enhance the mechanical strength without remarkable degradation in residual resistivity ratio (RRR) by increasing content of selected additive elements. Nickel is the suitable additive element because it has very low solubility in aluminum and low increasing rate in electric resistivity, and furthermore, nickel and aluminum form intermetallic compounds which effectively resist the motion of dislocations. First, Al-0.1wt%Ni alloy was developed for the ATLAS thin superconducting solenoid. This alloy achieved high yield strength of 79 MPa (R.T.) and 117 MPa (4.2 K) with high RRR of 490 after cold working of 21% in area reduction. These highly balanced properties could not be achieved with previously developed solid-solution aluminum alloys. ...

  10. Natural history of high-grade cervical intraepithelial neoplasia : a review of prognostic biomarkers

    NARCIS (Netherlands)

    Koeneman, Margot M.; Kruitwagen, Roy F. P. M.; Nijman, Hans W.; Slangen, Brigitte F. M.; Van Gorp, Toon; Kruse, Arnold-Jan

    The natural history of high-grade cervical intraepithelial neoplasia (CIN) is largely unpredictable and current histopathological examination is unable to differentiate between lesions that will regress and those that will not. Therefore, most high-grade lesions are currently treated by surgical

  11. A Case Study of a High School Transition Program into the Ninth Grade

    Science.gov (United States)

    Durant, Jamie Douglas

    2009-01-01

    This dissertation was designed to examine and evaluate the effectiveness of a Ninth-Grade Transition Program at a Rural High School in Central North Carolina. The ninth grade is a pivotal year that determines which students will prevail and which students will fail to finish high school (Hertzog, 2003). It is essential that schools put in place…

  12. Extent of high-grade prostatic intraepithelial neoplasia is not a ...

    African Journals Online (AJOL)

    Objective: High-grade prostatic intraepithelial neoplasia (PIN) is a well accepted pre-cursor of invasive prostate cancer. Most investigators agree that a diagnosis of high-grade PIN warrants repeat transrectal ultrasound guided biopsy. We set out to investigate risk factors for cancer among a modern cohort of men with ...

  13. Effects of surface treating methods of high-strength carbon fibers on interfacial properties of epoxy resin matrix composite

    International Nuclear Information System (INIS)

    Ma, Quansheng; Gu, Yizhuo; Li, Min; Wang, Shaokai; Zhang, Zuoguang

    2016-01-01

    Highlights: • Effects of surface treating on T700 grade high strength carbon fiber were discussed. • The fiber surface roughness, surface energy and chemical properties are analyzed. • The surface treating significantly affect the properties of carbon fiber. • The composite with electrolysis and sizing-fiber has the highest mechanical properties. - Abstract: This paper aims to study the effects of surface treating methods, including electrolysis of anodic oxidation, sizing and heat treatment at 200 °C, on physical and chemical properties of T700 grade high-strength carbon fiber GQ4522. The fiber surface roughness, surface energy and chemical properties were analyzed for different treated carbon fibers, using atom force microscopy, contact angle, Fourier transformed infrared and X-ray photoelectron spectroscopy, respectively. The results show that the adopted surface treating methods significantly affect surface roughness, surface energy and active chemical groups of the studied carbon fibers. Electrolysis and sizing can increase the roughness, surface energy and chemical groups on surface, while heat treatment leads to decreases in surface energy and chemical groups due to chemical reaction of sizing. Then, unidirectional epoxy 5228 matrix composite laminates were prepared using different treated GQ4522 fibers, and interlaminar shear strength and flexural property were measured. It is revealed that the composite using electrolysis and sizing-fiber has the strongest interfacial bonding strength, indicating the important roles of the two treating processes on interfacial adhesion. Moreover, the composite using heat-treating fiber has lower mechanical properties, which is attributed to the decrease of chemical bonding between fiber surface and matrix after high temperature treatment of fiber.

  14. Prostatectomy-based validation of combined urine and plasma test for predicting high grade prostate cancer

    DEFF Research Database (Denmark)

    Albitar, Maher; Ma, Wanlong; Lund, Lars

    2018-01-01

    . The urine/plasma assay confirmed a previous validation and was highly accurate in predicting the presence of high-grade PCa (Gleason ≥3 + 4) with sensitivity between 88% and 95% as verified by prostatectomy findings. GS was upgraded after prostatectomy in 27% of patients and downgraded in 12% of patients......BACKGROUND: Distinguishing between low- and high-grade prostate cancers (PCa) is important, but biopsy may underestimate the actual grade of cancer. We have previously shown that urine/plasma-based prostate-specific biomarkers can predict high grade PCa. Our objective was to determine the accuracy......, designated a Gleason Score (GS) based on biopsy, and assigned to prostatectomy prior to participation in the study. The primary outcome measure was the urine/plasma test accuracy in predicting high grade PCa on prostatectomy compared with biopsy findings. Sensitivity and specificity were calculated using...

  15. High Performance Slab-on-Grade Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

    2015-09-01

    ?A more accurate assessment of SOG foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated). The optimum insulation strategy was applied to single and multi-family residential buildings in climate zone 4 - 7. The highest site energy savings of 5% was realized for a single family home in Duluth, MN, and the lowest savings of 1.4 % for a 4-unit townhouse in Richmond, VA. SOG foundation insulation retrofit simple paybacks ranged from 18 to 47 years. There are other benefits of SOG foundation insulation resulting from the increase in the slab surface temperatures. These include increased occupant thermal comfort, and a decrease in slab surface condensation particularly around the slab perimeter.

  16. Translucency and Strength of High Translucency Monolithic Zirconium Oxide Materials

    Science.gov (United States)

    2016-05-17

    sintered and polished according to the manufacturer’s instructions (n=5). Translucency parameter was calculated using a spectrophotometer (VITA Easyshade...manufacturing metal -ceramic restorations which had strength and accuracy due to the cast metal , but also provided esthetically pleasing results because...of the ceramic (Shillingburg et al. , 1997). For years, dentists have used metal -ceramic crowns to provide their patients with strong, long lasting

  17. Behaviour of high-strength concrete incorporating ground ...

    African Journals Online (AJOL)

    The fibers used were fine polypropylene monofilaments. They were cylindrical of 12 mm length with a nominal diameter of 30 μm. The PP-F density was 0.9 g/cm3 and the melting temperature was 160-165°C. The tensile strength was 300 MPa. The modulus of elasticity of polypropylene fibres was 3 GPa. 2.2. Cure condition.

  18. Correlation between Compressive Strength and Rheological Parameters of High-Performance Concrete

    Directory of Open Access Journals (Sweden)

    Aminul Islam Laskar

    2007-01-01

    Full Text Available Compressive strength is greatly influenced by the performance of concrete in its fresh stage such as uniform mixing, proper compaction, resistance to segregation during transporting and placing. Attempt has, therefore, been made to correlate compressive strength to the rheological behavior of high performance concrete with a modified setup of parallel plate rheometer. Modified setup considers the shearing of concrete at the centre of the cylindrical container that takes into account the resistance between concrete and the vertical side of the wall. It has been observed that compressive strength increases steeply as the yield strength increases up to a certain level. Plastic viscosity, however, shows optimum value for maximum compressive strength.

  19. DAPK1, MGMT and RARB promoter methylation as biomarkers for high-grade cervical lesions.

    Science.gov (United States)

    Sun, Yin; Li, Shu; Shen, Keng; Ye, Shuang; Cao, Dongyan; Yang, Jiaxin

    2015-01-01

    Gene promoter methylation may be used a potential biomarker for detecting solid tumor including cervical cancer. Here, we used methylation sensitive-high resolution melting (MS-HRM) analysis to detecting promoter methylation ratios of DAPK1, MGMT and RARB gene in patients with different cervical disease grade. The detection of gene promoter methylation was conducted in two hundred fifty patients' samples including normal cytology (n=48), cervical intraepithelial neoplasia grade 1 (CIN1, n=54), cervical intraepithelial neoplasia grade 2 (CIN2, n=47), cervical intraepithelial neoplasia grade 3 (CIN3, n=56) and cervical squamous cell carcinomas (SCS, n=45). We found there were a significant positive correlation between the promoter methylation status of DAPK1 and cervical disease grade (P=0.022). In addition, the methylated promoters of DAPK1 combined with MGMT, MGMT combined with RARB, DAPK1 combined with RARB were positive correlated with cervical disease grade (P methylated were positive correlated with cervical disease grade (P methylation could be used to be a potential marker for diagnosing high grade cervical disease (HSIL and SCC). The cutoff values for the methylation rates of all these genes were 0-5%. Regrettably, only the methylation of MGMT combined with DAPK1 gave 43.4% sensitivity and 68.6% specificity. The current results indicated that MS-HRM-based testing for DNA methylations of MGMT plus DAPK1 genes holds some promise for high grade cervical disease screening.

  20. Extraordinary high strength Ti-Zr-Ta alloys through nanoscaled, dual-cubic spinodal reinforcement.

    Science.gov (United States)

    Biesiekierski, Arne; Ping, Dehai; Li, Yuncang; Lin, Jixing; Munir, Khurram S; Yamabe-Mitarai, Yoko; Wen, Cuie

    2017-04-15

    While titanium alloys represent the current state-of-the-art for orthopedic biomaterials, concerns still remain over their modulus. Circumventing this via increased porosity requires high elastic admissible strains, yet also limits traditional thermomechanical strengthening techniques. To this end, a novel β-type Ti-Zr-Ta alloy system, comprised of Ti-45Zr-10Ta, Ti-40Zr-14Ta, Ti-35Zr-18Ta and Ti-30Zr-22Ta, was designed and characterized mechanically and microstructurally. As-cast, this system displayed extremely high yield strengths and elastic admissible strains, up to 1.4GPa and potentially 1.48%, respectively. This strength was attributed to a nanoscaled, cuboidal structure of semi-coherent, dual body-centered cubic (BCC) phases, arising from the thermodynamics of interaction between Ta and Zr; this morphology occurring with dual BCC-phases is heretofore unreported in Ti-based alloys. Further, cell proliferation investigated by MTS assay suggests this was achieved without sacrificing biocompatibility, with no significant difference to either empty-well or commercially-pure Ti controls noted. The current research details microstructural, mechanical, and biological investigations into four novel biomedical alloys in a hitherto uninvestigated region of the Ti-Zr-Ta alloy system; Ti-45Zr-10Ta, Ti-40Zr-14Ta, Ti-35Zr-18Ta and Ti-30Zr-22Ta. We find that the investigated alloys display 0.2% yield strengths of up to 1.40GPa and elastic admissible strains of up to 1.48%, along with biological properties comparable to that seen in the conventional metallic biomaterial ASTM Grade-2 CP-Ti, achieved in the complete absence of traditional thermomechanical processing techniques. This is attributed to the presence of a dual-BCC cuboidal nanostructure, achieved via spinodal decomposition; while similar structures have been reported in e.g. Ni-based superalloys, we believe this is the first such structure investigated in a Ti-based material. As such, this work is felt to be of

  1. Sustainable normal and high strength recycled aggregate concretes using crushed tested cylinders as coarse aggregates

    Directory of Open Access Journals (Sweden)

    Bilal S. Hamad

    2017-12-01

    Full Text Available The paper reports on a research program that was designed at the American University of Beirut (AUB to investigate the fresh and hardened mechanical properties of a high performance concrete mix produced with partial or full substitution of crushed natural lime-stone aggregates with recycled aggregates from crushed tested cylinders in batching plants. Choosing crushed cylinders as source of recycling would result in reusing portion of the waste products of the concrete production industry. An extensive concrete batching and testing program was conducted to achieve two optimum normal and high strength concrete mixes. The variables were the nominal concrete strength (28 or 60 MPa and the percentage replacement of natural coarse aggregates with recycled aggregates from crushed tested cylinders (0, 20, 40, 60, 80, or 100%. Normal strength tested cylinders were used as source of the recycled aggregates for the normal strength concrete (NSC mix and high strength tested cylinders were used for the high strength concrete (HSC mix. Tests on the trial batches included plastic state slump and hardened state mechanical properties including cylinder compressive strength, cylinder splitting tensile strength, modulus of elasticity, and standard beams flexural strength. The results indicated no significant effect on the slump and around 10% average reduction in the hardened mechanical properties for both investigated levels of concrete compressive strength.

  2. Influence of Eco-Friendly Mineral Additives on Early Age Compressive Strength and Temperature Development of High-Performance Concrete

    Science.gov (United States)

    Kaszynska, Maria; Skibicki, Szymon

    2017-12-01

    High-performance concrete (HPC) which contains increased amount of both higher grade cement and pozzolanic additives generates more hydration heat than the ordinary concrete. Prolonged periods of elevated temperature influence the rate of hydration process in result affecting the development of early-age strength and subsequent mechanical properties. The purpose of the presented research is to determine the relationship between the kinetics of the heat generation process and the compressive strength of early-age high performance concrete. All mixes were based on the Portland Cement CEM I 52.5 with between 7.5% to 15% of the cement mass replaced by the silica fume or metakaolin. Two characteristic for HPC water/binder ratios of w/b = 0.2 and w/b = 0.3 were chosen. A superplasticizer was used to maintain a 20-50 mm slump. Compressive strength was determined at 8h, 24h, 3, 7 and 28 days on 10x10x10 cm specimens that were cured in a calorimeter in a constant temperature of T = 20°C. The temperature inside the concrete was monitored continuously for 7 days. The study determined that the early-age strength (tconcrete with reactive mineral additives is lower than concrete without them. This is clearly visible for concretes with metakaolin which had the lowest compressive strength in early stages of hardening. The amount of the superplasticizer significantly influenced the early-age compressive strength of concrete. Concretes with additives reached the maximum temperature later than the concretes without them.

  3. High-grade internal rectal prolapse: Does it explain so-called "idiopathic" faecal incontinence?

    Science.gov (United States)

    Bloemendaal, A L A; Buchs, N C; Prapasrivorakul, S; Cunningham, C; Jones, O M; Hompes, R; Lindsey, I

    2016-01-01

    Faecal incontinence is a multifactorial disorder, with multiple treatment options. The role of internal rectal prolapse in the aetiology of faecal incontinence is debated. Recent data has shown the importance of high-grade internal rectal prolapse in case of faecal incontinence. We aimed to determine the incidence and relevance of internal rectal prolapse in patients with faecal incontinence without an anal sphincter defect. Patient data, collected in a prospective pelvic floor database, were assessed. All females with moderate to severe pure faecal incontinence, without obstructed defecation and sphincter muscle defects, were included. Data on defecation proctography, anorectal physiology and incontinence scores were analysed. Of 2082 females in the database, 174 fitted the inclusion criteria. High-grade internal rectal prolapse was found in 49% of patients and was associated predominantly with urge faecal incontinence. Passive faecal incontinence was more common in low-grade compared to high-grade internal rectal prolapse patients. Maximum resting pressure was lower in older patients and in patients with high-grade compared to low-grade internal rectal prolapse. Internal rectal prolapse grade was not significantly correlated with faecal incontinence severity score. High-grade internal rectal prolapse is common in female patients suffering particularly urge faecal incontinence, without anal sphincter lesions. Defecation proctography should be routine in the work up of faecal incontinence. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

  4. Improved Middle Grades Schools for Improved High School Readiness: Ten Best Practices in the Middle Grades

    Science.gov (United States)

    Bottoms, Gene; Timberlake, Allison

    2012-01-01

    In 2009, the Southern Regional Education Board (SREB) Committee to Improve High School Graduation Rates and Achievement, led by then-Governor Sonny Perdue of Georgia, released a report of 10 key recommendations for ensuring more students graduate from high school, and they graduate ready for college and careers. Among these 10 recommendations was…

  5. High Temperature Strength of Oxide Dispersion Strengthened Aluminium

    DEFF Research Database (Denmark)

    Clauer, A.H.; Hansen, Niels

    1984-01-01

    The tensile flow stress of coarse-grained dispersion strengthened Al-Al2O3 materials were measured as a function of temperature (77–873 K) and volume fraction (0.19-0.92 vol.%) of aluminium oxide. For the same material, the creep strength was determined as a function of temperature in the range 573...... is proportional to the Orowan stress and it does not fall below about 0.5-0.7 of the Orowan stress. During creep even at stresses near the threshold stress a dislocation substructure develops consisting of dense tangles surrounding the larger particles and the particle clusters in addition to a coarse dislocation...

  6. Tough hybrid ceramic-based material with high strength

    International Nuclear Information System (INIS)

    Guo, Shuqi; Kagawa, Yutaka; Nishimura, Toshiyuki

    2012-01-01

    This study describes a tough and strong hybrid ceramic material consisting of platelet-like zirconium compounds and metal. A mixture of boron carbide and excess zirconium powder was heated to 1900 °C using a liquid-phase reaction sintering technique to produce a platelet-like ZrB 2 -based hybrid ceramic bonded by a thin zirconium layer. The platelet-like ZrB 2 grains were randomly present in the as-sintered hybrid ceramic. Relative to non-hybrid ceramics, the fracture toughness and flexural strength of the hybrid ceramic increased by approximately 2-fold.

  7. Stress corrosion in high-strength aluminum alloys

    Science.gov (United States)

    Dorward, R. C.; Hasse, K. R.

    1980-01-01

    Report describes results of stress-corrosion tests on aluminum alloys 7075, 7475, 7050, and 7049. Tests compare performance of original stress-corrosion-resistant (SCR) aluminum, 7075, with newer, higher-strength SCR alloys. Alloys 7050 and 7049 are found superior in short-transverse cross-corrosion resistance to older 7075 alloy; all alloys are subject to self-loading effect caused by wedging of corrosion products in cracks. Effect causes cracks to continue to grow, even at very-low externally applied loads.

  8. Effect of Hybrid Fibers on the Mechanical Properties of High Strength Concrete

    Directory of Open Access Journals (Sweden)

    Hamid H. Hussein, Saeed K. Rejeb Hayder T. Abd

    2014-04-01

    Full Text Available In this study, high strength concrete of 75 MPa compressive strength was investigated. The experimental program was designed to study the effect of fibers and hybrid fibers (steel and polypropylene fibers on the fresh (workability and wet density and hardened properties (compressive strength, splitting strength, flexural strength and dry density of high strength concrete. Results show that decreases in slump flow of all concrete mixtures containing steel, polypropylene and hybrid fibers compared with control mix (0% fiber. Hybrid high strength concrete with steel and polypropylene fibers showed superior compressive, splitting, flexural strengths over the others concrete without or with single fibers content. The test results indicate that the maximum increase in compressive and flexural strengths are obtains with the hybridization ratio (70%steel + 30% polypropylene and were equal to 14.54% and 23.34% respectively, compared with the control mix. While, the maximum increase in splitting tensile strength with (100% steel fiber + 0 polypropylene is 21.19%. 

  9. Internal and External Oxidation of Manganese in Advanced High Strength Steels

    NARCIS (Netherlands)

    Aghaei Lashgari, V.

    2014-01-01

    Advanced high strength steels (AHSS) have been used extensively in the automotive industries. The main characteristic of these steels is combination of high strength and enhanced formability that makes them very attractive for automotive application. However, the major drawback of these steels is

  10. Continuous, flexible, and high-strength superconducting Nb3Ge and Nb3Sn filaments

    International Nuclear Information System (INIS)

    Ahmad, I.; Heffernan, W.J.

    1976-01-01

    Fabrication of continuous, flexible, and high-strength (1600 MN/m 2 ) composite filaments of Nb 3 Ge (T/subc/ 18 0 K) and Nb 3 Sn is reported, involving chemical vapor deposition of these compounds on Nb-coated high-strength W--1% ThO 2 filaments

  11. High strength fibre reinforced concrete : Static and fatigue behaviour in bending

    NARCIS (Netherlands)

    Lappa, E.S.

    2007-01-01

    Recently, a number of high strength and ultra high strength steel fibre concretes have been developed. Since these materials seem very suitable for structures that might be prone to fatigue failure, such as bridge decks, the understanding of the static and fatigue bending behaviour is vital. In

  12. A graded d-spacing multilayer telescope for high-energy x-ray astronomy

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; WESTERGAARD, NJ

    1992-01-01

    A high energy telescope design is presented which combines grazing incidence geometry with Bragg reflection in a graded d-spacing multilayer coating to obtain significant sensitivity up to --6O keV. The concept utilizes total reflection and first order Bragg reflection in a graded d-spacing multi...

  13. Exploring High-Achieving Sixth Grade Students' Erroneous Answers and Misconceptions on the Angle Concept

    Science.gov (United States)

    Bütüner, Suphi Önder; Filiz, Mehmet

    2017-01-01

    The aim of this research was to investigate high achievers' erroneous answers and misconceptions on the angle concept. The participants consisted of 233 grade 6 students drawn from eight classes in two well-established elementary schools of Trabzon, Turkey. All the participants were considered to be current achievers in mathematics, graded 4 or 5…

  14. A Comparison of High School Student Interests across Three Grade and Ability Levels.

    Science.gov (United States)

    Gill, Newell T.

    1980-01-01

    Students (Grades 9-11) in two Florida metropolitan high schools rated their interest in 28 topics, such as travel, popular music, religion, the opposite sex, war, and politics. Interests were analyzed by sex, grade, and ability track in English (Honors, Average, Basic). Findings, especially those on romantic interests, are discussed. (SJL)

  15. CIP2A protein expression in high-grade, high-stage bladder cancer

    International Nuclear Information System (INIS)

    Huang, Lisa P; Savoly, Diana; Sidi, Abraham A; Adelson, Martin E; Mordechai, Eli; Trama, Jason P

    2012-01-01

    Bladder cancer is one of the most common cancers in the United States. Numerous markers have been evaluated for suitability of bladder cancer detection and surveillance. However, few of them are acceptable as a routine tool. Therefore, there exists a continuing need for an assay that detects the presence of bladder cancer in humans. It would be advantageous to develop an assay with a protein that is associated with the development of bladder cancer. We have identified the cancerous inhibitor of PP2A (CIP2A) protein as a novel bladder cancer biomarker. In this study, Western blot analysis was used to assess the expression level of CIP2A protein in bladder cancer cell lines and bladder cancer patient tissues (n = 43). Our studies indicated CIP2A protein was abundantly expressed in bladder cancer cell lines but not in nontumor epithelial cell lines. Furthermore, CIP2A was specifically expressed in transitional cell carcinoma (TCC) of the bladder tumor tissues but not in adjacent nontumor bladder tissue. Our data showed that CIP2A protein detection in high-grade TCC tissues had a sensitivity of 65%, which is 3.4-fold higher than that seen in low-grade TCC tissues (19%). The level of CIP2A protein expression increased with the stage of disease (12%, 27%, 67%, and 100% for pTa, pT1, pT2, and pT3 tumor, respectively). In conclusion, our studies suggest that CIP2A protein is specifically expressed in human bladder tumors. CIP2A is preferentially expressed in high-grade and high-stage TCC tumors, which are high-risk and invasive tumors. Our studies reported here support the role of CIP2A in bladder cancer progression and its usefulness for the surveillance of recurrence or progression of human bladder cancer

  16. An Experimental Study of High Strength-High Volume Fly Ash Concrete for Sustainable Construction Industry

    Science.gov (United States)

    Kate, Gunavant K.; Thakare, Sunil B., Dr.

    2017-08-01

    Concrete is the most widely used building material in the construction of infrastructures such as buildings, bridges, highways, dams, and many other facilities. This paper reports the development, the basic idea, the main properties of high strength-high volume fly ash with application in concrete associated with the development and implementation of Sustainable Properties of High Volume Fly Ash Concrete (HVFAC) Mixtures and Early Age Shrinkage and mechanical properties of concrete for 7,28,56 and 90days. Another alternative to make environment-friendly concrete is the development of high strength-high-volume fly ash concrete which is an synthesized from materials of geological origin or by-product materials such as fly ash which is rich in silicon and aluminum. In this paper 6 concrete mixtures were produced to evaluate the effect of key parameters on the mechanical properties of concrete and its behavior. The study key parameters are; binder material content, cement replacement ratios, and the steel fibers used to High Volume Fly Ash mixtures for increasing performance of concrete.

  17. Preparation of high purification and food grade phosphoric acid from technical grade phosphoric acid by liquid-liquid detraction method

    International Nuclear Information System (INIS)

    Alimoradi, M.; Borji, F.; Kishani, A.

    2002-01-01

    Pay attention to increasing consumption of high purification and food grade phosphoric acid in various industries and food industries and on in on hand and lack of preparation between production and distribution of this products its purification is so vital. In this article of liquid-liquid extraction method with normal hexane-mixture of ammonia and acetone-diisopropyl alcohol and normal butanol solvents and these determination of distribution coefficient each one with ph-me try titration we can evaluate effectiveness and sufficiency each one. Because of proper coefficient distribution and its local production of normal butanol solvent and low price is the best solvent. To phosphoric acid modifying coefficient distribution for extraction of phosphoric acid we can add a little value sulfuric acid to the mixture and to remove flouride impurity we add a little Na 2 O. After extraction stage extracted phosphoric acid in the normal strips by evaluating with distilled water and then by passing the carbon active bed and following passes of cationic resine column and concentrated with vacuum distillation. Conclusion of this article is produce of phosphoric acid 85% w/w and food grade from impure phosphoric acid 52% w/w with technical grade

  18. The research on delayed fracture behavior of high-strength bolts in steel structure

    Science.gov (United States)

    Li, Guo dong; Li, Nan

    2017-07-01

    High-strength bolts have been widely used in power plants. However, the high-strength bolts which being employed in pumping station, steel structure and pipeline anti-whip structure have been found delayed fracture for many times in a power plant, this will affect the reliability of steel fracture and bring blow risk caused by falling objects. The high-strength bolt with delayed fracture was carried out fracture analysis, metallurgical analysis, chemical analysis, mechanical analysis, as well as bolts installation analysis, it can be comprehensively confirmed that the direct cause of high-strength bolts delayed fracture is the stress corrosion, and the root cause of high-strength bolts delayed fracture should be the improper installation at the initial and the imperfect routine anti-corrosion maintenance.

  19. Welding simulation and fatigue assessment of tubular K-joints in high-strength steel

    International Nuclear Information System (INIS)

    Zamiri Akhlaghi, F.

    2014-01-01

    Application of newly developed high strength steel hollow sections is increasing in construction industry – especially for bridge structures – due to their satisfactory material properties and fabrication advantages. These sections allow for longer spans, more slender structures. Savings in weight and volume of material compared to traditional steel grades increase sustainability of construction and compensate for part of higher unit cost of material. Nevertheless, use of high strength steels cannot be promoted unless potential fatigue issues are properly addressed. Two fabrication methods are currently available for the planar Warren trusses made of circular hollow sections (CHS): welding the tubes together, or using cast steel nodes and connecting truss members to them by girth welds. Previous research on tubular bridge trusses indicates that the problematic fatigue cracking sites for the first fabrication method are located at weld toes in the gap region of the truss joints. For the second method, cracking occurs at the root of CHS–cast butt welds. Fatigue performance of these two methods were investigated by constant amplitude fatigue testing of two full scale trusses made of steel grade S690QH and with a geometry similar to previous S355J2H investigation. Fatigue lives of K-joints were in agreement with current recommended code values. For CHS–cast welded connections, no visible cracking was observed up to 2£10 6 cycles. Due to the effect of residual stresses, fatigue cracking was observed in compressive joints as well as tensile joints. Indeed, tensile welding residual stresses keep the crack open during all or part of the compressive load cycle. Their distribution and impact on fatigue life of tubular joints has not been fully investigated before for a complex detail such as Tubular K-joint made of high strength steel. Experimental and numerical methods were utilized for assessment of welding residual stresses. Neutron diffraction experiments were

  20. Welding simulation and fatigue assessment of tubular K-joints in high-strength steel

    Energy Technology Data Exchange (ETDEWEB)

    Zamiri Akhlaghi, F.

    2014-07-01

    Application of newly developed high strength steel hollow sections is increasing in construction industry – especially for bridge structures – due to their satisfactory material properties and fabrication advantages. These sections allow for longer spans, more slender structures. Savings in weight and volume of material compared to traditional steel grades increase sustainability of construction and compensate for part of higher unit cost of material. Nevertheless, use of high strength steels cannot be promoted unless potential fatigue issues are properly addressed. Two fabrication methods are currently available for the planar Warren trusses made of circular hollow sections (CHS): welding the tubes together, or using cast steel nodes and connecting truss members to them by girth welds. Previous research on tubular bridge trusses indicates that the problematic fatigue cracking sites for the first fabrication method are located at weld toes in the gap region of the truss joints. For the second method, cracking occurs at the root of CHS–cast butt welds. Fatigue performance of these two methods were investigated by constant amplitude fatigue testing of two full scale trusses made of steel grade S690QH and with a geometry similar to previous S355J2H investigation. Fatigue lives of K-joints were in agreement with current recommended code values. For CHS–cast welded connections, no visible cracking was observed up to 2£10{sup 6} cycles. Due to the effect of residual stresses, fatigue cracking was observed in compressive joints as well as tensile joints. Indeed, tensile welding residual stresses keep the crack open during all or part of the compressive load cycle. Their distribution and impact on fatigue life of tubular joints has not been fully investigated before for a complex detail such as Tubular K-joint made of high strength steel. Experimental and numerical methods were utilized for assessment of welding residual stresses. Neutron diffraction experiments

  1. A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.’s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension

    Directory of Open Access Journals (Sweden)

    Hideyuki Usa

    2017-01-01

    Full Text Available This study attempted to develop a formula for predicting maximum muscle strength value for young, middle-aged, and elderly adults using theoretical Grade 3 muscle strength value (moment fair: Mf—the static muscular moment to support a limb segment against gravity—from the manual muscle test by Daniels et al. A total of 130 healthy Japanese individuals divided by age group performed isometric muscle contractions at maximum effort for various movements of hip joint flexion and extension and knee joint flexion and extension, and the accompanying resisting force was measured and maximum muscle strength value (moment max, Mm was calculated. Body weight and limb segment length (thigh and lower leg length were measured, and Mf was calculated using anthropometric measures and theoretical calculation. There was a linear correlation between Mf and Mm in each of the four movement types in all groups, excepting knee flexion in elderly. However, the formula for predicting maximum muscle strength was not sufficiently compatible in middle-aged and elderly adults, suggesting that the formula obtained in this study is applicable in young adults only.

  2. Experimental Study of Confined Low-, Medium- and High-Strength Concrete Subjected to Concentric Compression

    Directory of Open Access Journals (Sweden)

    Antonius

    2012-11-01

    Full Text Available An experimental study of 23 low-, medium- and high-strength concrete columns is presented in this paper. Square-confined concrete columns without longitudinal reinforcement were designed, and tested under concentric axial compression. The columns were made of concrete with a compressive strength ranging between 30 MPa and 70 MPa. The test parameters in the study are concrete compressive strengths and confining steel properties, i.e. spacing, volumetric ratios and configurations. The effects of these parameters on the strength and ductility of square-confined concrete were evaluated. Of the specimens tested in this study, the columns made with higher-strength concrete produced less strength enhancement and ductility than those with lower-strength concrete. The steel configurations were found to have an important role in governing the strength and ductility of the confined high-strength concrete. Moreover, several models of strength enhancement for confined concrete available in the literature turned out to be quite accurate in predicting the experimental results.

  3. Undifferentiated pleomorphic sarcoma: indolent, tail-like recurrence of a high-grade tumor

    Energy Technology Data Exchange (ETDEWEB)

    Alpert, Justin S. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Boland, Patrick [Memorial Sloan Kettering Cancer Center, Division of Orthopaedic Surgery, Department of Surgery, New York, NY (United States); Weill Medical College of Cornell University, New York, NY (United States); Hameed, Meera [Memorial Sloan Kettering Cancer Center, Department of Pathology, New York, NY (United States); Panicek, David M. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Weill Medical College of Cornell University, New York, NY (United States)

    2018-01-15

    Recurrence of a soft tissue sarcoma typically manifests as a round or oval mass at imaging, and recurrent high-grade soft tissue sarcomas generally enlarge relatively rapidly. We present a case of high-grade undifferentiated pleomorphic sarcoma in the calf of a 48-year-old male that recurred as a thin, curvilinear ''tail'' of enhancing tissue at magnetic resonance imaging (MRI), with extremely indolent growth over a 7-year period. The unusual imaging finding of a slowly enlarging ''tail'' should not be dismissed as postoperative changes, even for a high-grade soft tissue sarcoma. (orig.)

  4. Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on dipolar copolymers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Daugaard, Anders Egede

    2014-01-01

    Dielectric elastomers (DES) are a promising new transducer technology, but high driving voltages limit their current commercial potential. One method used to lower driving voltage is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric permi......-4-nitrobenzene. Here, a high increase in dielectric permittivity (similar to 70%) was obtained without compromising other favourable DE properties such as elastic modulus, gel fraction, dielectric loss and electrical breakdown strength. © 2014 Elsevier Ltd. All rights reserved.......Dielectric elastomers (DES) are a promising new transducer technology, but high driving voltages limit their current commercial potential. One method used to lower driving voltage is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric...

  5. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    Directory of Open Access Journals (Sweden)

    Solikin Mochamad

    2017-01-01

    Full Text Available High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly Ash Concrete. The experiment and data analysis were prepared using minitab, a statistic software for design of experimental. The specimens were concrete cylinder with diameter of 15 cm and height of 30 cm, tested for its compressive strength at 56 days. The result of the research demonstrates that high volume fly ash concrete can produce comparable compressive strength which meets the strength of OPC design strength especially for high strength concrete. In addition, the best mix proportion to achieve the design strength is the combination of high strength concrete and 50% content of fly ash. Moreover, the use of spraying method for curing method of concrete on site is still recommended as it would not significantly reduce the compressive strength result.

  6. Welding high-strength aluminum alloys at the Paton Institute

    Energy Technology Data Exchange (ETDEWEB)

    Kuchuk, Yatsenko, S.I.; Cherednichok, V.T.; Semenov, L.A. (E.O. Paton Electric Welding Inst., Kiev (Ukraine))

    1993-07-01

    The choice of the flash method for welding aluminum-alloy sections was governed first of all by the possibility of producing homogeneous-structure joints with the minimum amount of possible discontinuities and an insignificant metal strength loss in the welding zone. The aluminum alloy welding technology under consideration relies on the method of flash welding without using any protective atmospheres. The reason is first of all that a complex cross-sectional shape of workpieces being joined, their configuration and considerable overall dimensions make it difficult to use chambers of any type. Besides, conducted studies ascertained that in flash welding, in contrast to various fusion welding processes, the use of protective atmospheres or a vacuum is of little benefit. Here are the results of studying the specifics of thermal and electric processes in flashing, the physical features of weld joint formation, the basics of the welding technology, and the characteristics of the equipment.

  7. Zirconia-alumina composites of high mechanical strength

    International Nuclear Information System (INIS)

    Pyda, W.; Pyda, A.

    2004-01-01

    Commercial zirconia (stabilized with 3 mol% yttria) and alumina powders of submicron size were used to produce ceramic matrix composites in the ZrO 2 -Al 2 O 3 system. Homogeneous mixtures of both constituent powders were prepared by means pf physical mixing in water exploiting a heterofloculation effect. The mixtures were consolidated using two methods: (i). Cold isostatic pressing of the samples under 300 MPa followed by pressureless sintering in air, (ii). hot pressing under 25 MPa in argon. The samples were sintered for 2 h at 1500-1650 o C. Detailed characterization was made with respect of the powder properties, packing of the particles in green compacts and microstructure of the consolidated composites. Studied was an influence of alumina content and the consolidation method on mechanical properties of the composites. A bending strength of 17±0.2 GPa was measured for the TZP material which contained 5 vol.% of alumina particles. (author)

  8. A population-based study of high-grade gliomas and mutated isocitrate dehydrogenase 1

    DEFF Research Database (Denmark)

    Dahlrot, Rikke H; Kristensen, Bjarne W; Hjelmborg, Jacob

    2012-01-01

    High-grade gliomas have a dismal prognosis, and prognostic factors are needed to optimize treatment algorithms. In this study we identified clinical prognostic factors as well as the prognostic value of isocitrate dehydrogenase 1 (IDH1) status in a population-based group of patients with high......-grade gliomas. Using the Danish Cancer Registry and the Danish Pathology Databank we identified 359 patients: 234 had WHO grade IV gliomas, 58 had WHO grade III gliomas, and 67 were diagnosed clinically. Mutated IDH1 was predominantly observed in oligodendroglial tumors (WHO grade III). Patients with mutated...... IDH1 had a significantly better outcome than patients with wildtype IDH1: 2-year OS 59% and 18%, respectively (HR 0.38, 95% CI 0.21-0.68). However, when adjusting for other prognostic factors, IDH1 status was not a significant independent prognostic factor (HR=0.58, 95% CI 0.32-1.07). Young age...

  9. Classifying low-grade and high-grade bladder cancer using label-free serum surface-enhanced Raman spectroscopy and support vector machine

    Science.gov (United States)

    Zhang, Yanjiao; Lai, Xiaoping; Zeng, Qiuyao; Li, Linfang; Lin, Lin; Li, Shaoxin; Liu, Zhiming; Su, Chengkang; Qi, Minni; Guo, Zhouyi

    2018-03-01

    This study aims to classify low-grade and high-grade bladder cancer (BC) patients using serum surface-enhanced Raman scattering (SERS) spectra and support vector machine (SVM) algorithms. Serum SERS spectra are acquired from 88 serum samples with silver nanoparticles as the SERS-active substrate. Diagnostic accuracies of 96.4% and 95.4% are obtained when differentiating the serum SERS spectra of all BC patients versus normal subjects and low-grade versus high-grade BC patients, respectively, with optimal SVM classifier models. This study demonstrates that the serum SERS technique combined with SVM has great potential to noninvasively detect and classify high-grade and low-grade BC patients.

  10. Evaluation of a highway bridge constructed using high strength lightweight concrete bridge girders.

    Science.gov (United States)

    2011-04-01

    The use of high performance concretes to provide longer bridge spans has been limited due to the capacity of existing infrastructure to handle the load of the girders during transportation. The use of High Strength Lightweight Concrete (HSLW) can pro...

  11. Three-Sheet Spot Welding of Advanced High-Strength Steels

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Friis, Kasper Storgaard; Zhang, W.

    2011-01-01

    The automotive industry has introduced the three-layer weld configuration, which represents new challenges compared to normal two-sheet lap welds. The process is further complicated by introducing high-strength steels in the joint. The present article investigates the weldability of thin, low....... The weld mechanisms are analyzed numerically and compared with metallographic analyses showing how the primary bonding mechanism between the thin, low-carbon steel sheet and the thicker sheet of high-strength steel is solid-state bonding, whereas the two high-strength steels are joined by melting, forming...... a weld nugget at their mutual interface. Despite the absence of the typical fusion nugget through the interface between the low-carbon steel and high-strength steel, the weld strengths obtained are acceptable. The failure mechanism in destructive testing is ductile fracture with plug failure....

  12. Failure analysis of high strength pipeline with single and multiple corrosions

    International Nuclear Information System (INIS)

    Chen, Yanfei; Zhang, Hong; Zhang, Juan; Li, Xin; Zhou, Jing

    2015-01-01

    Highlights: • We study failure of high strength pipelines with single corrosion. • We give regression equations for failure pressure prediction. • We propose assessment procedure for pipelines with multiple corrosions. - Abstract: Corrosion will compromise safety operation of oil and gas pipelines, accurate determination of failure pressure finds importance in residual strength assessment and corrosion allowance design of onshore and offshore pipelines. This paper investigates failure pressure of high strength pipeline with single and multiple corrosions using nonlinear finite element analysis. On the basis of developed regression equations for failure pressure prediction of high strength pipeline with single corrosion, the paper proposes an assessment procedure for predicting failure pressure of high strength pipeline with multiple corrosions. Furthermore, failure pressures predicted by proposed solutions are compared with experimental results and various assessment methods available in literature, where accuracy and versatility are demonstrated

  13. The evaluation on clamping force of high strength bolts by length parameter

    International Nuclear Information System (INIS)

    Kim, Kang-Seok; Nah, Hwan-Seon; Lee, Hyeon-Ju; Lee, Kang-Min

    2009-01-01

    It has been reported that the length parameter of high strength bolts results in the variance in tension loads. The required turn for each length is specified in AISC RCSC specification. This study was focused on evaluating any influence on the clamping torque subjected to length parameter of high strength bolts. The two kinds of high strength bolts of specimen are as follows; High Strength Hexagon bolt defined on ASTM A490 and Torque Shear Bolt on KS B 2819. The length parameter ranged from 60mm(3d) to 140mm(7d). The torque, turn of nut and the clamping force were analyzed to review whether length parameter can be affected on the required tension load. To test whether the length parameter has an impact on the torque and turn of nut for the required strength and clamping force, statistical analysis is carried out. (author)

  14. Microstructure-property relationship in microalloyed high-strength steel welds

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lei

    2017-04-01

    of steel being joined. In Ti-containing steel, increased heat Input extended the softened zone width, which caused a significant decrease in hardness and then resulted in failure in this area. Therefore, limited heat Input was used to shift failure position to base material. But this was not observed in the other two steels. Hence, small differences in microalloy addition exhibited large variation in tensile properties. Among the three steels, Ti-containing welds were found to have the most pronounced softening, followed by Ti+V-containing welds and finally Nb-containing welds. This varied softening phenomenon was related to two significant processes supported by the results of additional dilatometry simulation: phase transformation and tempering behaviour. In the Ti-containing steel, the phase Transformation product ferrite was large-sized, as a consequence of initial large austenite grains. This led to the decreased corresponding hardness of the Ti-containing steel. Furthermore, lower tempering resistance in Ti-containing steel as compared to Nb-containing steel, resulted in additional softening effect in the softened HAZ. Therefore, steel alloy identification and heat Input during welding were critical, proven by the experimentation within the same S690QL steel grade. This work emphasised the influence of microalloy elements on weld microstructure and mechanical properties in welded joints. Knowledge of this delicate balance between steel alloy design and appropriate welding parameters is critical for the end product. Thus, this work provides specific recommendations and results to ensure proper welding practice and steel design of microalloyed high-strength steels.

  15. Microstructure-property relationship in microalloyed high-strength steel welds

    International Nuclear Information System (INIS)

    Zhang, Lei

    2017-01-01

    of steel being joined. In Ti-containing steel, increased heat Input extended the softened zone width, which caused a significant decrease in hardness and then resulted in failure in this area. Therefore, limited heat Input was used to shift failure position to base material. But this was not observed in the other two steels. Hence, small differences in microalloy addition exhibited large variation in tensile properties. Among the three steels, Ti-containing welds were found to have the most pronounced softening, followed by Ti+V-containing welds and finally Nb-containing welds. This varied softening phenomenon was related to two significant processes supported by the results of additional dilatometry simulation: phase transformation and tempering behaviour. In the Ti-containing steel, the phase Transformation product ferrite was large-sized, as a consequence of initial large austenite grains. This led to the decreased corresponding hardness of the Ti-containing steel. Furthermore, lower tempering resistance in Ti-containing steel as compared to Nb-containing steel, resulted in additional softening effect in the softened HAZ. Therefore, steel alloy identification and heat Input during welding were critical, proven by the experimentation within the same S690QL steel grade. This work emphasised the influence of microalloy elements on weld microstructure and mechanical properties in welded joints. Knowledge of this delicate balance between steel alloy design and appropriate welding parameters is critical for the end product. Thus, this work provides specific recommendations and results to ensure proper welding practice and steel design of microalloyed high-strength steels.

  16. Studied of actinide colloids in high-ionic strength groundwaters

    International Nuclear Information System (INIS)

    Kadkhodayan, B.; Zhao, P.; Marquez, L.N.

    1995-01-01

    Proposed plans for permanent disposal of transuranic wastes in geologic repositories require the development of an actinide source-term model that predicts the total concentrations of mobile actinides both near field and far-field environments. An actinide source-term model must quantify mobile actinide-bearing species, which may be present as dissolved species in several possible oxidation states or as suspended colloidal particles. In this presentation, we describe results of experiments with several actinides in Na-Ca-Mg-Cl-SO 4 brines with ionic strengths ranging from 0.8 to 8 molal, designed to assess the formation of intrinsic colloids (Eigenkollide or real colloids), and their temporal behavior e.g., changes in concentration and size. We have implemented a test matrix that provides us with the basis to understand the behavior of actinides with +3, +4, +5, and +6 oxidation states, as a function of pH (3 to 11) and actinide concentration (10 -8 - 10 -4 molar). Colloid sizes were estimated using sequential filtration and ultrafiltration techniques. Colloidal particles were characterized with scanning electron microscopy and energy-dispersive x-ray spectrometry. The oxidation states of the actinides were investigated with absorption spectroscopy

  17. Effects of cathodic protection on cracking of high-strength pipeline steels

    Energy Technology Data Exchange (ETDEWEB)

    Elboujdaini, M.; Revie, R. W.; Attard, M. [CANMET Materials Technology Laboratory, Ottawa, ON(Canada)], email: melboujd@nrcan.gc.ca

    2010-07-01

    Four strength levels of pipeline steels, ranging from X-70 to X-120, were compared to determine whether higher strength materials are more susceptible to hydrogen embrittlement under cathodic protection. Ductility was measured in a solution at four protection levels, going from no cathodic protection to 500 mV of overprotection. All four steels showed loss of ductility under cathodic protection. Under cathodic polarization, the loss of ductility increased with the strength of the steel and the activity of the potential. After slow-strain-rate experiments conducted in air and examination of fracture surfaces, it is concluded that application of cathodic potentials, cathodic overprotection, higher strength of steel, and exposure to aqueous solution are factors that decrease the ductility of steel. Hydrogen reduction seems to be an important factor in ductility reduction and fractures. Observations suggest that high-strength pipelines need better control of cathodic protection than lower-strength pipelines.

  18. Interfacial (Fiber-matrix) Properties of High-strength Mortar (150 MPa) from Fiber Pullout

    DEFF Research Database (Denmark)

    Shannag, M.J.; Brincker, Rune; Hansen, Will

    1996-01-01

    DSP mortar has significantly improved interfacial properties compared to ordinary strength mortar. These results are important in the understanding of the role of steel fibers in improving the tensile properties of high-strength, brittle, cement-matrix composites....... The steel fiber-matrix properties of high-strength mortar (150 MPa), such as DSP (densified small particle), are obtained and compared to an ordinary strength mortar (40 MPa) using a specially designed fiber pullout apparatus. A new method for estimating the debonding energy of the interfacial...... zone from the experimental pullout curve is presented. The method is used to separate the areas under the pullout curve corresponding to debonding and friction. The predictions are compared to other methods in the literature. The proposed method seems to provide less variations in the results. The high-strength...

  19. Design of high-temperature high-strength Al-Ti-V-Zr alloys

    International Nuclear Information System (INIS)

    Lee, H.M.

    1990-01-01

    This paper reports that it seems plausible to develop high-strength Al-base alloys useful up to 698K in view of the behavior of nickel base superalloys which resist degradation of mechanical properties to 75 pct of their absolute melting temperature. For high temperature Al alloys, the dispersed hardening phase must not undergo phase transformation to an undesirable phase during long time exposure at the temperature of interest. An additional factor to be considered is the stability of the hardening phase with respect to Ostwald ripening. This coarsening resistance is necessary so that the required strength level can be maintained after the long-time service at high temperatures. The equilibrium crystal structures of Al 3 Ti, Al 3 V and Al 3 Zr are tetragonal D0 22 , D0 22 and D0 23 , respectively. At the temperatures of interest, around 698K, vanadium and titanium are mutually substitutable in the form of Al 3 (Ti, V). Much of titanium and vanadium can be substituted for zirconium in the D0 23 - type Al 3 Zr compound, creating Al 3 (Ti, Zr) and Al 3 (V, Zr), respectively. In particular, it has been reported that fcc L1 2 -structured Al 3 M dispersoids form in the rapidly solidified Al-V-Zr and Al-Ti-Zr systems and both L1 2 and D0 23 -structured Al 3 M phases showed slow coarsening kinetics

  20. Demonstration of Ultra High-Strength Nanocrystalline Copper Alloys for Military Applications

    Science.gov (United States)

    2012-01-22

    the consolidated samples was determined by using Archimedes principle . Processing diagram 1 shows a general flow process for the steps involved in...Demonstration of Ultrahigh-Strength Nanocrystalline Copper Alloys for Military Applications Project Number: WP-2139 Performing...1-26-2012 Final Dec 2010 - Dec 2011 Demonstration of Ultra High-Strength Nanocrystalline Copper Alloys for Military Applications WP-2139Kris

  1. Machinability of HP-9-4-20 high-strength steel

    Energy Technology Data Exchange (ETDEWEB)

    Morris, T.O.

    1976-01-01

    Machinability tests were conducted on HP-9-4-20 high-strength steel. This material was found to be easier to machine to close tolerances than the maraging steels when heat treated to a similar yield strength and fracture-toughness level. (auth)

  2. The influence of cellular structures on flow stress of high strength components manufactured using SLM

    DEFF Research Database (Denmark)

    Mahshid, Rasoul; Hansen, Hans Nørgaard; Loft Højbjerre, Klaus

    2016-01-01

    of cellular materials on compression strength. The specimens are manufactured additively using industrial 3D printing systems from high-strength alloy. The material has the right mechanical properties for manufacturing tool components. This includes samples with solid and lattice structures. The Compression...

  3. Effects of surface treating methods of high-strength carbon fibers on interfacial properties of epoxy resin matrix composite

    Science.gov (United States)

    Ma, Quansheng; Gu, Yizhuo; Li, Min; Wang, Shaokai; Zhang, Zuoguang

    2016-08-01

    This paper aims to study the effects of surface treating methods, including electrolysis of anodic oxidation, sizing and heat treatment at 200 °C, on physical and chemical properties of T700 grade high-strength carbon fiber GQ4522. The fiber surface roughness, surface energy and chemical properties were analyzed for different treated carbon fibers, using atom force microscopy, contact angle, Fourier transformed infrared and X-ray photoelectron spectroscopy, respectively. The results show that the adopted surface treating methods significantly affect surface roughness, surface energy and active chemical groups of the studied carbon fibers. Electrolysis and sizing can increase the roughness, surface energy and chemical groups on surface, while heat treatment leads to decreases in surface energy and chemical groups due to chemical reaction of sizing. Then, unidirectional epoxy 5228 matrix composite laminates were prepared using different treated GQ4522 fibers, and interlaminar shear strength and flexural property were measured. It is revealed that the composite using electrolysis and sizing-fiber has the strongest interfacial bonding strength, indicating the important roles of the two treating processes on interfacial adhesion. Moreover, the composite using heat-treating fiber has lower mechanical properties, which is attributed to the decrease of chemical bonding between fiber surface and matrix after high temperature treatment of fiber.

  4. ADAR2 editing activity in newly diagnosed versus relapsed pediatric high-grade astrocytomas

    International Nuclear Information System (INIS)

    Tomaselli, Sara; Galeano, Federica; Massimi, Luca; Di Rocco, Concezio; Lauriola, Libero; Mastronuzzi, Angela; Locatelli, Franco; Gallo, Angela

    2013-01-01

    High-grade (WHO grade III and IV) astrocytomas are aggressive malignant brain tumors affecting humans with a high risk of recurrence in both children and adults. To date, limited information is available on the genetic and molecular alterations important in the onset and progression of pediatric high-grade astrocytomas and, even less, on the prognostic factors that influence long-term outcome in children with recurrence. A-to-I RNA editing is an essential post-transcriptional mechanism that can alter the nucleotide sequence of several RNAs and is mediated by the ADAR enzymes. ADAR2 editing activity is particularly important in mammalian brain and is impaired in both adult and pediatric high-grade astrocytomas. Moreover, we have recently shown that the recovered ADAR2 activity in high-grade astrocytomas inhibits in vivo tumor growth. The aim of the present study is to investigate whether changes may occur in ADAR2-mediated RNA editing profiles of relapsed high-grade astrocytomas compared to their respective specimens collected at diagnosis, in four pediatric patients. Total RNAs extracted from all tumor samples and controls were tested for RNA editing levels (by direct sequencing on cDNA pools) and for ADAR2 mRNA expression (by qRT-PCR). A significant loss of ADAR2-editing activity was observed in the newly diagnosed and recurrent astrocytomas in comparison to normal brain. Surprisingly, we found a substantial rescue of ADAR2 editing activity in the relapsed tumor of the only patient showing prolonged survival. High-grade astrocytomas display a generalized loss of ADAR2-mediated RNA editing at both diagnosis and relapse. However, a peculiar Case, in complete remission of disease, displayed a total rescue of RNA editing at relapse, intriguingly suggesting ADAR2 activity/expression as a possible marker for long-term survival of patients with high-grade astrocytomas

  5. Analysis of Mathematical Connection Ability and Mathematical Disposition Students of 11th Grade Vocational High School

    OpenAIRE

    Fajar Tri Setiawan; Hardi Suyitno; Bambang Eko Susilo

    2017-01-01

    The purpose of this research was to described mathematical connection ability, mathematical disposition students of eleventh grade Vocational High School. This research also was to described mathematical connection ability reviewed by mathematical disposition and mathematical disposition reviewed by mathematical connection ability. The social situation was students of eleventh grade Eight Vocational High School. The subject in this research was students in the level of capacity to mathematica...

  6. Graded-host phosphorescent light-emitting diodes with high efficiency and reduced roll-off

    Directory of Open Access Journals (Sweden)

    S. W. Liu

    2012-03-01

    Full Text Available We demonstrated graded-host phosphorescent organic light-emitting diodes with high efficiency and reduced efficiency roll-off. The emissive layer of the graded host device consists of both electron and hole transport type hosts, 1,3,5-tris(N-phenylbenzimidazole-2-ylbenzene (TPBI and 4,4′,4′′-tris(N-carbazolyltriphenylamine, respectively, with graded composition, and the phosphorescent red emitter bis(2-phenylquinoline (acetylacetonate iridium(III, which was uniformly doped into the graded host matrix. The graded host device shows improved quantum efficiency and power efficiency with significantly reduced efficiency roll-off as compared to the unipolar-host and double layer heterojunction host devices.

  7. Effect of microstructure on the impact toughness of high strength steels

    Directory of Open Access Journals (Sweden)

    Gutiérrez, Isabel

    2014-12-01

    Full Text Available One of the major challenges in the development of new steel grades is to get increasingly high strength combined with a low ductile brittle transition temperature and a high upper shelf energy. This requires the appropriate microstructural design. Toughness in steels is controlled by different microstructural constituents. Some of them, like inclusions, are intrinsic while others happening at different microstructural scales relate to processing conditions. A series of empirical equations express the transition temperature as a sum of contributions from substitutional solutes, free nitrogen, carbides, pearlite, grain size and eventually precipitation strengthening. Aimed at developing a methodology that could be applied to high strength steels, microstructures with a selected degree of complexity were produced at laboratory in a Nb-microalloyed steel. As a result a model has been developed that consistently predicts the Charpy curves for ferrite-pearlite, bainitic and quenched and tempered microstructures using as input data microstructural parameters. This model becomes a good tool for microstructural design.El desarrollo de nuevos grados de acero se tropieza con frecuencia con la necesidad de incrementar la resistencia mecánica al mismo tiempo que se reduce la temperatura de transición dúctil-frágil y se eleva la energía del palier dúctil. Hacer frente a este reto requiere un diseño microestructural. La tenacidad en aceros está controlada por diferentes constituyentes microestructurales. Algunos de ellos, como las inclusiones son intrínsecos, pero otros que se manifiestan a diferentes escalas microestructurales dependen de las condiciones de proceso. Existen algunas ecuaciones empíricas que permiten calcular para ferrita-perlita en aceros de bajo carbono la temperatura de transición como suma de contribuciones de elementos en solución sólida, nitrógeno libre, carburos, fracción de perlita, tamaño de grano y, eventualmente

  8. Unitarity corrections and high field strengths in high energy hard collisions

    International Nuclear Information System (INIS)

    Kovchegov, Y.V.; Mueller, A.H.

    1997-01-01

    Unitarity corrections to the BFKL description of high energy hard scattering are viewed in large N c QCD in light-cone quantization. In a center of mass frame unitarity corrections to high energy hard scattering are manifestly perturbatively calculable and unrelated to questions of parton saturation. In a frame where one of the hadrons is initially at rest unitarity corrections are related to parton saturation effects and involve potential strengths A μ ∝1/g. In such a frame we describe the high energy scattering in terms of the expectation value of a Wilson loop. The large potentials A μ ∝1/g are shown to be pure gauge terms allowing perturbation theory to again describe unitarity corrections and parton saturation effects. Genuine nonperturbative effects only come in at energies well beyond those energies where unitarity constraints first become important. (orig.)

  9. Connections in Precast Buildings using Ultra High-Strength Fibre Reinforced Concrete

    DEFF Research Database (Denmark)

    Hansen, Lars Pilegaard

    1995-01-01

    Ultra high-strength concrete adds new dimensions to the design of concrete structures. It is a brittle material but introducing fibres into the matrix changes the material into a highly ductile material. Furthermore, the fibre reinforcement increases the anchorage of traditional reinforcement bars...... and the fire resistance. Such a fibre reinforced ultra high-strength material has been used to develop a simple joint solution between slab elements in a column - slab building system....

  10. Detection of High Grade Prostate Cancer among PLCO Participants Using a Prespecified 4-Kallikrein Marker Panel.

    Science.gov (United States)

    Kim, Eric H; Andriole, Gerald L; Crawford, E David; Sjoberg, Daniel D; Assel, Melissa; Vickers, Andrew J; Lilja, Hans

    2017-04-01

    We assessed the performance of a 4-kallikrein panel with and without microseminoprotein-β to predict high grade (Gleason 7+/Gleason Grade Group 2+) prostate cancer on biopsy in a multiethnic cohort from PLCO (Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial). Levels of free, intact, total prostate specific antigen, human kallikrein-2 and microseminoprotein-β were measured while blinded to outcomes in cryopreserved serum from men in the intervention arm of PLCO. Marker levels of 946 men, of whom 100 were African American, were incorporated into a prespecified statistical model to predict high grade prostate cancer on biopsy. The detection of high grade prostate cancer in 94 men (10%) was enhanced by the 4-kallikrein panel with an AUC of 0.79 compared to 0.73 for PCPTRC (Prostate Cancer Prevention Trial Risk Calculator), representing a 0.060 increase (95% CI 0.032-0.088, p panel. In African American men, the 4-kallikrein panel model also enhanced high grade prostate cancer detection over that of prostate specific antigen (AUC 0.80 vs 0.67). As an illustration of clinical implications, using 1 cutoff point for biopsy (6% risk of high grade prostate cancer) with the 4-kallikrein panel model would have eliminated unnecessary biopsies in 420 per 1,000 men (42%) while detecting high grade prostate cancer in 83 of 93 (88%). In a multiethnic United States population, the 4-kallikrein panel demonstrated improved risk discrimination for high grade prostate cancer over conventional clinical variables (age, prostate specific antigen and digital rectal examination) as well as PCPTRC. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  11. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    OpenAIRE

    Solikin Mochamad; Setiawan Budi

    2017-01-01

    High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC) and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly ...

  12. Enhanced long-term strength and durability of shotcrete with high-strength C{sub 12}A{sub 7} mineral-based accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Won, Jong-Pil, E-mail: jpwon@konkuk.ac.kr; Hwang, Un-Jong; Lee, Su-Jin

    2015-10-15

    This study evaluated the performance of shotcrete using high strength C{sub 12}A{sub 7} mineral-based accelerator that has been developed to improve the durability and long-term strength. Rebound, compressive strength and flexural strength were tested in the field. Test result showed that existing C{sub 12}A{sub 7} mineral-based accelerator exhibits better early strength than the high-strength C{sub 12}A{sub 7} mineral-based accelerator until the early age, but high-strength C{sub 12}A{sub 7} mineral-based accelerator shows about 29% higher at the long-term age of 28 days. Microstructural analysis such as scanning electron microscope (SEM), X-ray diffraction (XRD) and nitrogen adsorption method was evaluated to analyze long-term strength development mechanism of high strength C{sub 12}A{sub 7} mineral-based accelerator. As analysis result, it had more dense structure due to the reaction product by adding material that used to enhanced strength. It had better resistance performance in chloride ion penetration, freezing–thawing and carbonation than shotcrete that used existing C{sub 12}A{sub 7} mineral-based accelerator.

  13. Corrosion Assessment Guidance for High Strength Steels (Phase 1)

    Science.gov (United States)

    2009-08-01

    The continuing worldwide demand for natural gas presents major challenges to pipeline operators. There is increasing need to construct long distance, high capacity transmission pipelines, particularly in the more remote areas of Arctic North America,...

  14. Gastric low-grade MALT lymphoma, high-grade MALT lymphoma and diffuse large B cell lymphoma show different frequencies of trisomy

    NARCIS (Netherlands)

    Hoeve, M A; Gisbertz, I A; Schouten, H C; Schuuring, E; Bot, F J; Hermans, J; Hopman, A; Kluin, P M; Arends, J E; van Krieken, J H

    1999-01-01

    Gastric MALT lymphoma is a distinct entity related to Helicobacter pylori gastritis. Some studies suggest a role for trisomy 3 in the genesis of these lymphomas, but they mainly focused on low-grade MALT lymphoma. Gastric MALT lymphoma, however, comprises a spectrum from low- to high-grade cases.

  15. Interfacial (Fiber-matrix) Properties of High-strength Mortar (150 MPa) from Fiber Pullout

    DEFF Research Database (Denmark)

    Shannag, M.J.; Brincker, Rune; Hansen, Will

    1996-01-01

     The steel fiber-matrix properties of high-strength mortar (150 MPa), such as DSP (densified small particle), are obtained and compared to an ordinary strength mortar (40 MPa) using a specially designed fiber pullout apparatus. A new method for estimating the debonding energy of the interfacial z...... DSP mortar has significantly improved interfacial properties compared to ordinary strength mortar. These results are important in the understanding of the role of steel fibers in improving the tensile properties of high-strength, brittle, cement-matrix composites....... The steel fiber-matrix properties of high-strength mortar (150 MPa), such as DSP (densified small particle), are obtained and compared to an ordinary strength mortar (40 MPa) using a specially designed fiber pullout apparatus. A new method for estimating the debonding energy of the interfacial...... zone from the experimental pullout curve is presented. The method is used to separate the areas under the pullout curve corresponding to debonding and friction. The predictions are compared to other methods in the literature. The proposed method seems to provide less variations in the results. The high-strength...

  16. The Spalling of Geopolymer High Strength Concrete Wall Panels and Cylinders Under Hydrocarbon Fire

    Directory of Open Access Journals (Sweden)

    Mohd Ali Ahmad Zurisman

    2016-01-01

    Full Text Available Concrete structures were designed to withstand various types of environment conditions from mild to very severe conditions. Fire represents one of the most severe environmental conditions to which concrete structures may be subjected especially in close conduct structure like tunnel. This paper focuses on the spalling of geopolymer high strength concrete exposed to hydrocarbon fire for minimum 2 hours. From the fire test, geopolymer concrete can be classified as a good fire resistance construction materials based on spalling performance of high strength concrete when exposed to hydrocarbon fire. A maximum of 1% (excluding water moisture loss of spalling recorded for high strength geopolymer concrete wall panel. No explosive spallings were observed for high strength geopolymer concrete.

  17. Influence of curing regimes on compressive strength of ultra high ...

    Indian Academy of Sciences (India)

    The bridges and highways are being constructed inlarge number all around the globe using. UHPC, there is ... The properties of UHPC are different from high performance concrete and normal concrete. The curing ... ture, elimination of coarse aggregate, microstructure enhancement by heat curing, addition of steel fibres for ...

  18. Effect of microstructure on the high temperature strength of nitride ...

    Indian Academy of Sciences (India)

    Unknown

    chrome, Model No. Autoscan 60, USA). Existence of phases (α-, β-Si3N4, SiO2, etc) were determined by XRD technique. Both room temperature and high temperature. MOR were determined by 4-point loading in a bending ... Properties of nitride bonded SiC composite materials. Density (g/cm3). Open porosity Mean pore.

  19. High temperature high strength molybdenum and molybdenum-tungsten Ti-Zr-Hf-C alloys

    International Nuclear Information System (INIS)

    Eck, R.; Tinzl, J.

    1989-01-01

    TZM containing 0,5 % titanium, 0,08 % zirconium and 0,01-0,04 % carbon still is the most important molybdenum alloy. During the last years Zr-Hf-C and Hf-C containing alloys have been successfully developed and are in use at prominent consumers. Composition of Zr-Hf-C containing alloys could be optimized considering fabricability, low temperature ductility and required high temperature strength. Thermomechanical processes determine properties of semifinished and final products and are discussed in detail for the powder metallurgical way of production. Mechanical properties for short time and long term application of ZHM alloys are presented and discussed in comparison to the base metal and existing molybdenum based alloys. Demand for higher strength at usual temperature and higher working temperature not achievable with molybdenum base alloys led to the development of Zr-Hf-C and Hf-C dispersion strengthened molybdenum-tungsten alloys. Mechanical data of alloys are presented and advantages and disadvantages discussed in comparison to molybdenum based alloys. 8 refs., 17 figs., 1 tab. (Author)

  20. Impact of internal water reservoirs on shrinkage of high strength concrete

    OpenAIRE

    Drčar, Grega

    2013-01-01

    High strength concrete has lower water-cement ratio compared to regular concrete, which allows higher strength of the concrete. Because of low water-cement ratio, there is a lack of water during the process of hydration.During the transport of water from the capillary pores of concrete, high forces to the structure of the hardening cement paste were created. Because of this forces, the concrete shrinks, which creates cracks and therefore reduces durability of the concrete elements. In this...

  1. Energy Concept Understanding of High School Students: A Cross-Grade Study

    Science.gov (United States)

    Takaoglu, Zeynep Baskan

    2018-01-01

    Energy is a difficult concept to be understood by students of all levels. Thus, the aim of the study is to determine how high school students at different levels perceive the energy and related concepts. In line with this purpose, 173 students in total of which 57 ones of the 9th grade, 94 ones of the 10th grade and 22 ones of the 11th grade…

  2. PREVALENCE OF HUMAN PAPILLOMAVIRUS GENOTYPES IN LOW AND HIGH GRADE SQUAMOUS INTRAEPITHELIAL LESIONS AT CERVICAL TISSUE

    OpenAIRE

    Prasetyo, Rizki Eko; Mastutik, Gondo; Mustokoweni, Sjahjenny

    2017-01-01

    HPV infection is known to cause cervical cancer. This study aimed to identify the variant of HPV genotypes of cervical precancerous lesions from low grade squamous intraepithelial lesion  (LSIL) and high grade squamous intraepithelial lesion (HSIL). This was an explorative study using formalin fix paraffin embedded (FFPE) from cervical precancerous lesions at Dr. Soetomo Hospital, Surabaya. DNA was extracted from FFPE and hybridized for HPV genotyping using Ampliquality HPV Type Express kit (...

  3. Venous thromboembolism and survival in patients with high-grade glioma

    OpenAIRE

    Simanek, Ralph; Vormittag, Rainer; Hassler, Marco; Roessler, Karl; Schwarz, Martin; Zielinski, Christoph; Pabinger, Ingrid; Marosi, Christine

    2007-01-01

    Patients with malignancy, particularly patients with high-grade glioma (HGG; WHO grade III/IV), have an increased risk of venous thromboembolism (VTE). It has been suggested that VTE predicts survival in cancer patients. The aim of our study was to investigate the occurrence of symptomatic VTE and its impact on survival in patients with HGG. Consecutive patients (n = 63; 36 female, 27 male; median age, 58 years) who had neurosurgical intervention between October 2003 and December 2004 were fo...

  4. The effect of a high carbohydrate diet and glycogen depletion on graded maximal exercise

    OpenAIRE

    小林, 義雄; 細井, 輝男; 竹内, 敏子; 朴, 哲浩; 金, 享烈; 荒井, 康夫; Yoshio, Kobayashi; Teruo, Hosoi; Toshiko, Takeuchi; Cheol-Ho, Pak; Hyung-Ryul, Kim; Yasuo, Arai; 中京大学教養部健康スポーツ科学研究室; 中京大学教養部健康スポーツ科学研究室; 中京大学教養部健康スポーツ科学研究室

    1997-01-01

    The present investigation examined the influence of dietary carbohydrate (CHO) on the performance of graded maximal exercise on a bicycle ergometer. A group of highly trained college students [mean age 22.2 (SD 1.6) years] completed three trials of graded maximal exercise under three dietary conditions; normal diet (ND), glycogen depleted (CHD), and glycogen loaded (CHL) conditions with each trial separated by five days. Measurements of work done, maximal oxygen intake (Vo_), serum lactae, gl...

  5. Micro stresses in welded high-strength stainless steels

    International Nuclear Information System (INIS)

    Lukas, P.; Mikula, P.; Strunz, P.; Vrana, M.; Zaffagnini, M.; Janovec, J.; Macek, K.

    1995-01-01

    The dependence of residual stresses in martensitic-austenitic age-hardenable steels on a different technological treatment (welding by electron beam, postweld heat treatment) were investigated using neutron diffraction. Experiments were performed in NPI Rez on a high-resolution diffractometer equipped with cylindrically bent perfect crystals. The resolution of the instrument (Δd/d ∼ 10 -4 ; d-lattice spacing) enabled the authors to investigate plastic strains in weld joints

  6. High ionic strength or presence of inositol hexakisphosphate ...

    African Journals Online (AJOL)

    From kinetic data collected at high salt concentration, and in the presence of inositol hexakisphosphate, it is shown that the pKa of the sulphydryl increases to ca 9 and 7.7, respectively. Under these conditions, CysH3(125)β ceases to be an acid Bohr group. KEY WORDS: Haemoglobin, CysH3(125)β, pKa, Bohr effect, ...

  7. Stathmin is a highly sensitive and specific biomarker for vulvar high-grade squamous intraepithelial lesions.

    Science.gov (United States)

    Nooij, Linda S; Dreef, Enno J; Smit, Vincent T H B M; van Poelgeest, Mariëtte I E; Bosse, Tjalling

    2016-12-01

    Differentiating between human papilloma virus-dependent vulvar low-grade and high-grade squamous intraepithelial lesions (LSILs and HSILs) remains difficult in selected cases. Stathmin, a protein involved in cell cycle progression, might be a useful additional marker for this differentiation. The aim of this study was to investigate the additional diagnostic value of stathmin expression in vulvar intraepithelial neoplastic (VIN) lesions. Immunohistochemical analysis was used to evaluate stathmin, P16 and Ki67 expression in 91 samples, including LSILs (n=16), HSILs (n=50), differentiated VIN (dVIN; n=10), lichen sclerosis (LS; n=10) and normal vulvar tissue (n=5). Stathmin was expressed in more than one-third of the epithelium in all HSILs and in 20% of LSILs. P16 and Ki67 were expressed in more than one-third of the epithelium in 94% of HSILs and in 13% and 40% of LSILs, respectively. Stathmin was expressed in more than one-third of the epithelium in 10% of the dVIN and in none of the LS or normal lesions. P16 and Ki67 expression was not present in more than one-third of the epithelium in any of these lesions. The sensitivity of stathmin for differentiating between LSILs and HSILs was 100% compared with a sensitivity of 94% for both p16 and Ki67. The specificity of stathmin, p16 and Ki67 was 80%, 87% and 60%, respectively. Stathmin is a highly sensitive and specific biomarker for the diagnosis of vulvar HSIL. In addition to the more commonly used immunohistochemical markers p16 and Ki67, stathmin can be a useful diagnostic tool for identifying HSILs, especially in cases in which differentiating between LSIL and HSIL is difficult. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Blood magnesium, and the interaction with calcium, on the risk of high-grade prostate cancer.

    Directory of Open Access Journals (Sweden)

    Qi Dai

    2011-04-01

    Full Text Available Ionized calcium (Ca and magnesium (Mg compete as essential messengers to regulate cell proliferation and inflammation. We hypothesized that inadequate Mg levels, perhaps relative to Ca levels (e.g. a high Ca/Mg ratio are associated with greater prostate cancer risk.In this biomarker sub-study of the Nashville Men's Health Study (NMHS, we included 494 NMHS participants, consisting of 98 high-grade (Gleason≥7 and 100 low-grade cancer cases, 133 prostate intraepithelial neoplasia (PIN cases, and 163 controls without cancer or PIN at biopsy. Linear and logistic regression were used to determine associations between blood Ca, Mg, and the Ca/Mg ratio across controls and case groups while adjusting for potential confounding factors.Serum Mg levels were significantly lower, while the Ca/Mg ratio was significantly higher, among high-grade cases vs. controls (p = 0.04, p = 0.01, respectively. Elevated Mg was significantly associated with a lower risk of high-grade prostate cancer (OR = 0.26 (0.09, 0.85. An elevated Ca/Mg ratio was also associated with an increased risk of high-grade prostate cancer (OR = 2.81 (1.24, 6.36 adjusted for serum Ca and Mg. In contrast, blood Ca levels were not significantly associated with prostate cancer or PIN.Mg, Ca, or Ca/Mg levels were not associated with low-grade cancer, PIN, PSA levels, prostate volume, or BPH treatment.Low blood Mg levels and a high Ca/Mg ratio were significantly associated with high-grade prostate cancer. These findings suggest Mg affects prostate cancer risk perhaps through interacting with Ca.

  9. Compression specific toughness of normal strength steel fiber reinforced concrete (NSSFRC and high strength steel fiber reinforced concrete (HSSFRC

    Directory of Open Access Journals (Sweden)

    Khaled Marara

    2011-01-01

    Full Text Available Compression toughness tests were carried out on concrete cylinders reinforced with three different aspect ratios of hooked-end steel fibers 60, 75, and 83 and six different percentages of steel fibers 0.5, 1.0, 1.25, 1.5, 1.75, and 2.0% by volume of concrete. The w/c ratio used for the normal strength steel fiber reinforced concrete mixes (NSSFRC was 0.55, and the water-cementitious ratio (w/c+s for the high strength fiber reinforced concrete mixes (HSSFRC was 0.31. For each mix, three test cylinders were tested for compression specific toughness. The effect of fiber reinforcement index: volume of fibers × length/diameter ratio on compression specific toughness and also on the relationship between these two properties is presented in this paper. As a result, (a equations are proposed to quantify the effect of fibers on compression toughness ratio of concrete in terms of FRI, (b equations obtained in terms of FRI and compression specific toughness of plain concrete to estimate both compression specific toughness of NSSFRC and HSSFRC (N.m, (c equations obtained which represent the relationship between compression toughness index and FRI for NSSFRC and HSSFRC, respectively, and (d equations obtained to quantify the relationship between compression specific toughness index and fiber reinforcement index for NSSFRC and HSSFRC, respectively. The proposed equations give good correlation with the experimental values.

  10. Allograft Arthrodesis of the Knee in High-grade Osteosarcoma

    Directory of Open Access Journals (Sweden)

    Teng-Le Huang

    2005-09-01

    Conclusion: Due to the high rate of complications in this study, we conclude that allograft arthrodesis should be left as a salvage or “back-up” reconstructive procedure after resection of osteosarcoma around the knee, unless there are special indications for this procedure. We found allograft fracture to be the most common complication.

  11. Improved glucose tolerance after high-load strength training in patients undergoing dialysis

    DEFF Research Database (Denmark)

    Mølsted, Stig; Harrison, Adrian Paul; Eidemak, Inge

    2013-01-01

    Background/Aims: The aim of this controlled study was to investigate the effect of high-load strength training on glucose tolerance in patients undergoing dialysis. Methods: 23 patients treated by dialysis underwent a 16-week control period followed by 16 weeks of strength training three times....... After strength training the relative area of type 2X fibers was decreased. Muscle fiber size and capillary density remained unchanged. After the strength training, insulin concentrations were significantly lower in patients with impaired glucose tolerance or type 2 diabetes (n = 14) (fasting insulin...... glucose tolerance (n = 9). Conclusion: The conducted strength training was associated with a significant improvement in glucose tolerance in patients with impaired glucose tolerance or type 2 diabetes undergoing dialysis. The effect was apparently not associated with muscle hypertrophy, whereas the muscle...

  12. Laboratory criteria of crack resistance of high-strength steels for gas main pipelines

    Science.gov (United States)

    Pyshmintsev, I. Yu.; Arabei, A. B.; Farber, V. M.; Khotinov, V. A.; Lezhnin, N. V.

    2012-04-01

    Low-carbon ferrite-bainite pipe steels of the K65 (Kh80) strength grade produced by two manufacturing companies have been studied using different mechanical tests and fractographic analysis of fractured surfaces. The results demonstrate that the energy capacity a ( a c) and the true relative reduction at fracture φf upon tensile tests, as well as the level of KCV -40 ≥ 250 J/cm2 and the relative width of the zone of homogeneous ductile fracture L C/ B at the fracture surface of Charpy samples upon impact bending tests, can be used as the laboratory criteria of crack resistance.

  13. Save Time with a High-Performance Grading System

    Science.gov (United States)

    Slater, Timothy F.

    2005-09-01

    Tim Slater is an associate professor of astronomy at the University of Arizona, where he directs the Science and Mathematics Education Center and conducts research on teaching and learning of Earth and space science. Tim's contributions to this column have proven valuable for physics teachers at both high school and university levels. Here he shares some time-saving tips that will help the busy teacher give students valuable feedback.

  14. Material investigation of strength, deformation and toughness under high rates of loading

    International Nuclear Information System (INIS)

    Meyer, L.W.

    1988-01-01

    This paper reports analyses of inertial and other disturbing effects, in order to determine improvements of the testing methods for materials analysis under high rates of loading. Typical, misleading data in load-time diagrams of strength tests of materials under dynamic loads have been taken as a basis for the study which investigated the yield points, strength and deformation behaviour of four steels (the hot working steel X 45 CrSi 9 3; the low-alloy, high-strength, tempered steel 35 NiCrMo 12 5 as a typical specimen of the tempered steels; a carbon steel 46 Mn 7; and a high-strength austenitic steel X 3 CrNiMoNbN 23 17) in the load range of ε ≅ 10 -4 (quasi static) up to ε = 4x10 3 1/s. (orig./HP) [de

  15. Estimation on the clamping force of high strength bolt by temperature parameter

    International Nuclear Information System (INIS)

    Nah, Hwan-Seon; Kim, Kang-Seok; Lee, Hyeon-Ju; Kim, Woo-Bum

    2009-01-01

    In case of Korean nuclear power plant, the field design of bolted connection for steel structures has been changed from high strength hexagon bolt to torque shear bolt. The torque control method is mainly used as a clamping method of high strength bolt at construction site. However the torque coefficient affects the design strength in tension on the process of tightening by torque control. This is why it is obscure to assume quantitatively the direct tension induced into bolt. The determinant factor affected on the clamping force is ambient temperature as Korean standard B 2819 indicated. This study was planned to assess the expected clamping force on two kinds of high strength bolts considering temperature ranged from -10degC to 50degC. From test data subjected to temperature parameters, the equation to estimate the clamping force was extracted by regression analysis. (author)

  16. THEORETICAL ASPECTS, EXPERIMENTAL INVESTIGATIONS AND EFFICIENCY IN USAGE OF HIGH-STRENGTH CONCRETE FOR BRIDGE STRUCTURES

    Directory of Open Access Journals (Sweden)

    G. D. Liakhevich

    2014-01-01

    Full Text Available In Belarus concrete with strength up to 60 MPA is used for construction. At the same time high strength concrete with compressive strength above 60 MPA is widely used in all industrially developed countries. High- strength concrete is included in regulatory documents of the European Union and that fact has laid a solid foundation for its application. High strength concrete is produced using highly dispersed silica additives, such as micro-silica and plasticizers (super-plasticizers with a water/cement (w/c ratio not greater than 0.4.Theoretical aspects of high-strength concrete for bridge structures have been studied in the paper. The paper shows a positive impact of highly dispersed additives on structure and physico-mechanical properties of cement compositions, namely: reduction of total porosity of a cement stone in concrete while increasing volumetric concentration and dispersion of a filler; binding of calcium hydroxide with the help of amorphised micro-silica; increased activity of mineral additives during their thin shredding; acceleration of the initial stage of chemical hardening of cement compositions with highly dispersed particle additives that serve as centers of crystallization; “binder-additive” cluster formation due to high surface energy of highly dispersed additive particles; hardening of surface area between a cement stone and aggregates in concrete; high-strength concretes are gaining strength much faster than conventional concretes.Technology of preparation and composition of high-strength concrete using highly dispersed mineral additives and super-plasticizer has been developed in the paper. This concrete will ensure a higher density, wa- ter-and gas tightness, increased resistance to aggressive environment, reduced consumption of concrete and reinforcement, reduced transport and installation weight, increased initial strength, early easing of shutters and preliminary compression, increased length of bridge spans

  17. The effect of low temperatures on the fatigue of high-strength structural grade steels

    NARCIS (Netherlands)

    Walters, C.L.

    2014-01-01

    It is well-known that for fracture, ferritic steels undergo a sudden transition from ductile behavior at higher temperatures to brittle cleavage failure at lower temperatures. However, this phenomenon has not received much attention in the literature on fatigue. The so-called Fatigue Ductile-Brittle

  18. Dualism of precipitation morphology in high strength low alloy steel

    Energy Technology Data Exchange (ETDEWEB)

    Chih-Yuan, Chen, E-mail: chen6563@gmail.com [Department of Energy Engineering, National United University, Miaoli 36003, Taiwan (China); Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Chien-Chon, Chen [Department of Energy Engineering, National United University, Miaoli 36003, Taiwan (China); Jer-Ren, Yang, E-mail: jryang@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2015-02-25

    While the role of microalloying elements on precipitation strengthening in ferrite matrix during austenite/ferrite transformation is quite clear, some uncertainty still exists concerning the variability of the microhardness distribution of ferrite grains in the isothermal holding condition. The objective of the present study was to clarify the intrinsic characteristics of carbide precipitation morphology in the ferrite matrix under different processing temperatures and times and to correlate it with austenite decomposition kinetics to elucidate why a large microhardness distribution occurs at low isothermal holding temperature. Better understanding of carbide precipitation behavior can help researchers to determine the root cause of variation in microhardness distribution, which would allow metallurgists to produce high quality steels. Measurement with a Vickers hardness indenter revealed that, in specimens isothermally held at 625 °C, the range of Vickers hardness distribution was 240–420 after 5 min of isothermal holding, and 270–340 after 60 min. For specimens isothermally held at 725 °C, the range of Vickers hardness distribution was 200–330 for 5 min of isothermal holding, and 200–250 for 60 min. Therefore, the average microhardness decreased with the isothermal holding temperature and time, and a larger range of distribution occurred with short isothermal holding times. Transmission electron microscopy (TEM) images showed that interface precipitation and random precipitation can occur within the same ferrite grain. The reason is that the austenite decomposition rate varies with transformation temperature and time. An excessively fast austenite/ferrite interface movement velocity, which usually happens in small ferrite grains, would cause these ferrite grains with microalloying elements to exceed their solubility. Furthermore, these microalloying elements will be precipitated randomly after isothermal holding at longer times. Consequently, a large

  19. High-impact strength acrylic denture base material processed by autoclave.

    Science.gov (United States)

    Abdulwahhab, Salwan Sami

    2013-10-01

    To investigate the effect of two different cycles of autoclave processing on the transverse strength, impact strength, surface hardness and the porosity of high-impact strength acrylic denture base material. High Impact Acryl was the heat-cured acrylic denture base material included in the study. A total of 120 specimens were prepared, the specimens were grouped into: control groups in which high-impact strength acrylic resins processed by conventional water-bath processing technique (74°C for 1.5 h then boil for 30 min) and experimental groups in which high-impact strength acrylic resins processed by autoclave at 121°C, 210 kPa .The experimental groups were divided into (fast) groups for 15 min, and (slow) groups for 30 min. To study the effect of the autoclave processing (Tuttnauer 2540EA), four tests were conducted transverse strength (Instron universal testing machine), impact strength (Charpy tester), surface hardness (shore D), and porosity test. The results were analyzed to ANOVA and LSD test. In ANOVA test, there were highly significant differences between the results of the processing techniques in transverse, impact, hardness, and porosity test. The LSD test showed a significant difference between control and fast groups in transverse and hardness tests and a non-significant difference in impact test and a highly significant difference in porosity test; while, there were a highly significant differences between control and slow groups in all examined tests; finally, there were a non-significant difference between fast and slow groups in transverse and porosity tests and a highly significant difference in impact and hardness tests. In the autoclave processing technique, the slow (long) curing cycle improved the tested physical and mechanical properties as compared with the fast (short) curing cycle. The autoclave processing technique improved the tested physical and mechanical properties of High Impact Acryl. Copyright © 2013 Japan Prosthodontic Society

  20. Improving the prediction of strength and rigidity of structural timber by combining ultrasound techniques with visual grading parameters

    Directory of Open Access Journals (Sweden)

    Hermoso Prieto, E.

    2007-12-01

    Full Text Available The present study explores the possibility of using longitudinal ultrasound transmission to evaluate the bending strength and modulus of elasticity in structural timber made from the two species most commonly found in Spanish construction and rehabilitation works: Scots pine (Pinus sylvestris L. and Laricio pine (Pinus nigra Arn.. An analysis of 1305 Scots pine and 852 Laricio pine beams shows that ultrasound transmission velocity alone can predict neither the bending strength nor the modulus of elasticity and that other predictive variables are required.A series of models are proposed based on ultrasound transmission velocity measurements, the relative size of the largest face and edge knots, length and density. After running models for each species individually and for the two jointly, a single model is found to be suitable for both. The models proposed explain from 63 to 73 per cent of bending strength and modulus of elasticity variability.Se analiza la posibilidad de aplicar la técnica de transmisión longitudinal de ultrasonidos para la evaluación de la resistencia y módulo de elasticidad a flexión de la madera estructural de las dos especies de mayor interés constructivo y más amplia presencia en obras de rehabilitación: el pino silvestre (Pinus sylvestris L. y el pino laricio (Pinus nigra Arn.. Trabajando sobre un total de 1.305 vigas de pino silvestre y 852 de pino laricio se concluye que por sí sola la velocidad de transmisión de ultrasonidos no es un buen predictor ni de la resistencia ni del módulo de elasticidad en flexión, necesitando el complemento de otras variables predictoras. Se proponen diversos modelos basados en la medición de la velocidad de transmisión de ultrasonidos, de los diámetros relativos del nudo máximo de cara y de canto, de la longitud y de la densidad. Los modelos se proponen tanto a nivel especie como global, comprobándose que es posible emplear un modelo único para ambas especies. Los modelos

  1. [Experience of diagnosis and treatment of exogenous high-grade fever].

    Science.gov (United States)

    Xiong, Xing-jiang; Wang, Jie

    2011-06-01

    There is a regular pattern in the diagnosis and treatment of exogenous high-grade fever, of which the key point is formula syndrome identification. Syndrome differentiation of the six channels is appropriate for not only exogenous cold but also various other conditions. The diagnosis and treatment of high-grade fever can also follow the law of syndrome differentiation of the six channels. The theory of epidemic febrile diseases stems from and elaborates on an understanding of exogenous febrile conditions, so many effective formulas used to treat epidemic febrile diseases also have great value in the treatment of high-grade fever. Deteriorated syndrome, which is central to this condition, is very commonly seen in cases of high-grade fever, the key therapeutic principle of which is established according to syndromes. Allowing analysis that does not rigidly adhere to either established modern diagnosis or traditional Chinese syndromes, prominent achievements could be made in treating high-grade fever by summarizing the regular presenting patterns in terms of the constitution and symptoms.

  2. Low- to high-grade metamorphic transition in the Southern part of Karnataka Nucleus, India

    Science.gov (United States)

    Naqvi, S. M.

    1988-01-01

    The southern part of Karnataka Nucleus has a strong imprint of 2.6 Ga metamorphism. This has affected the schist belts of Karnataka Nucleus from greenschist to upper amphibolite facies. The higher grades of metamorphism are in the Holenarasipur, Nuggihalli, Krishnarajpet, Hadnur and Melkote schist belts. In the high grade transition zone, around Sargur only keels of schist belts are preserved and occur as highly dismembered, disconnected belts with the top and bottom of the stratigraphic column obliterated due to high grade metamorphism and accompanying migmatization. Absence of high-grade metamorphic minerals in the sediments of the Dharwar schist belts supports the contention that high grade metamorphism post-dated the Dharwar sedimentation and occurred around 2.6 Ga ago. Sargur type metamorphism occurred at upper crustal levels and charnockite type metamorphism occurred in lower crustal levels. The P-T conditions for the mineral assemblage in metapelites of Sargur Group indicate burial depths up to at least 15 km suggesting that they were subducted and later obducted during the development of Early Proterozoic Mobile Belt along the southern border of the Karnataka Nucleus.

  3. Research and development of intelligent controller for high-grade sanitary ware

    Science.gov (United States)

    Bao, Kongjun; Shen, Qingping

    2013-03-01

    With the social and economic development and people's living standards improve, more and more emphasis on modern society, people improve the quality of family life, the use of intelligent controller applications in high-grade sanitary ware physiotherapy students. Analysis of high-grade sanitary ware physiotherapy common functions pointed out in the production and use of the possible risks, proposed implementation of the system hardware and matching, given the system software implementation process. High-grade sanitary ware physiotherapy intelligent controller not only to achieve elegant and beautiful, simple, physical therapy, water power, deodorant, multi-function, intelligent control, to meet the consumers, the high-end sanitary ware market, strong demand, Accelerate the enterprise product Upgrade and improve the competitiveness of enterprises.

  4. The rupture strength of dissimilar joints in high temperature

    International Nuclear Information System (INIS)

    Groenwall, B.

    1992-05-01

    In dissimilar joints between austenitic stainless steels and ferritic steels the heat affected zone in the ferritic steel always is the weakest link. Two different joints where the ferritic steel has been 10CrMo910 (2.25Cr1Mo) and X20CrMoV121 respectively (162Cr1Mo0.3V) has been investigated through thermal cycling and isothermal creep testing. In this case the purpose has been to investigate the weakest link and therefore both 10CrMo910 and X20CrMoV121 have been welded to themselves using the TIG-method with Inconel 82 (70Cr20Cr3Mn2). 5Nb as filler wire. Crossweld specimens have been taken from the joints. To accelerate the testing the tip temperature at thermal cycling and the temperature at isothermal creep testing has been in the region 600-650 degrees C. Low ductile fracture, which is typical for failures in practice, has been obtained by using a moderate tensile stress, 63 N/mm 2 . In the high temperature range, 650 degrees C, the thermal cycling compared to the isothermal testing had no influence but in lower temperatures the cycling caused decreased time to rupture. The time to rupture in thermal cycling as well as in isothermal testing as a function of testing temperature can be fitted to exponential curve of type t = a x e bT (where t and T are time and temperature respectively). Through extrapolation of the measured data it has been found that 10CrMo910 in hard conditions that is thermal cycling has a life time at 500 degrees C of about 100 000 h. If the operational temperature is constant the life time will be about four times longer. The X20CrMoV121 on the other hand has a life time at thermal cycling at 500 degrees C and moderate tensile stress of about 3 000 000 h. This means that the tensile stress can be increased considerably. The cracks appear in 10CrMo910 closely to the fusion line but in the X20CrMoV121 steel cracking and fracture arise in the heat affected zone some millimeters from the fusion line. (au)

  5. Garnet Yield Strength at High Pressures and Implications for Upper Mantle and Transition Zone Rheology

    International Nuclear Information System (INIS)

    Kavner, A.

    2008-01-01

    Garnet helps control the mechanical behavior of the Earth's crust, mantle, and transition zone. Here, measurements are presented suggesting that garnet, long considered to be a high-viscosity phase, is actually weaker than the other dominant components in the transition zone. The mechanical behavior of garnet at high pressures was examined using radial diffraction techniques in the diamond anvil cell. The yield strength of grossular garnet was inferred from synchrotron X-ray measurements of differential lattice strains. The differential stress was found to increase from 1.3 (±0.6) GPa at a hydrostatic pressure 5.8 (±1.1) GPa to 4.1 (±0.4) GPa at 15.7 (±1.0) GPa, where it was level to 19 GPa. The strength results are consistent with inferred strength values for majorite garnet from measurements in the diamond cell normal geometry, bolstering the idea that garnet-structured materials may all have similar strengths. In this low-temperature, high differential stress regime, garnet is shown to be significantly weaker than anhydrous ringwoodite and to have a strength similar to hydrous ringwoodite. This result suggests that the presence of water in the transition zone may not be required to explain a weak rheology, and therefore models of transition zone behavior built assuming that garnet is the high-strength phase may need to be revised.

  6. Development of strength evaluation method for high-pressure ceramic components

    Energy Technology Data Exchange (ETDEWEB)

    Takegami, Hiroaki, E-mail: takegami.hiroaki@jaea.go.jp; Terada, Atsuhiko; Inagaki, Yoshiyuki

    2014-05-01

    Japan Atomic Energy Agency is conducting R and D on nuclear hydrogen production by the Iodine-Sulfur (IS) process. Since highly corrosive materials such as sulfuric and hydriodic acids are used in the IS process, it is very important to develop components made of corrosion resistant materials. Therefore, we have been developing a sulfuric acid decomposer made of a ceramic material, that is, silicon carbide (SiC), which shows excellent corrosion resistance to sulfuric acid. One of the key technological challenges for the practical use of a ceramic sulfuric acid decomposer made of SiC is to be licensed in accordance with the High Pressure Gas Safety Act for high-pressure operations of the IS process. Since the strength of a ceramic material depends on its geometric form, etc., the strength evaluation method required for a pressure design is not established. Therefore, we propose a novel strength evaluation method for SiC structures based on the effective volume theory in order to extend the range of application of the effective volume. We also developed a design method for ceramic apparatus with the strength evaluation method in order to obtain a license in accordance with the High Pressure Gas Safety Act. In this paper, the minimum strength of SiC components was calculated by Monte Carlo simulation, and the minimum strength evaluation method of SiC components was developed by using the results of simulation. The method was confirmed by fracture test of tube model and reference data.

  7. Process study of polycyanate resin for wet-filament wound high-strength composites

    Energy Technology Data Exchange (ETDEWEB)

    Frame, B.J.

    1997-12-31

    Polycyanate (or cyanate ester) resins offer advantages as composite matrices because of their high thermal stability, low outgassing, low water absorption and radiation resistance. This report describes the results of a processing study to develop high-strength hoop-wound composite by the wet-filament winding method using Toray T1000G carbon fiber and YLA RS-14 polycyanate resin as the constituent materials. T1000G/RS-14 composite cylinders were wet-wound and cured using different process schedules and then evaluated for hoop tensile strength and modulus, transverse flexural strength and short beam shear strength. The results of material characterization tests performed on the T1000G carbon fiber and RS-14 resin constituents used in this study are also presented.

  8. Development of the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP): reviewing measurement specific to the upper limb in tetraplegia.

    Science.gov (United States)

    Kalsi-Ryan, Sukhvinder; Curt, Armin; Verrier, Mary C; Fehlings, Michael G

    2012-09-01

    Primary outcome measures for the upper limb in trials concerning human spinal cord injury (SCI) need to distinguish between functional and neurological changes and require satisfying psychometric properties for clinical application. The Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) was developed by the International GRASSP Research and Design Team as a clinical outcome measure specific to the upper limbs for individuals with complete and incomplete tetraplegia (that is, paralysis or paresis). It can be administered across the continuum of recovery after acute cervical SCI. An international multicenter study (involving centers in North America and Europe) was conducted to apply the measure internationally and examine its applicability. The GRASSP is a multimodal test comprising 5 subtests for each upper limb: dorsal sensation, palmar sensation (tested with Semmes-Weinstein monofilaments), strength (tested with motor grading of 10 muscles), and prehension (distinguishes scores for qualitative and quantitative grasping). Thus, administration of the GRASSP results in 5 numerical scores that provide a comprehensive profile of upper-limb function. The established interrater and test-retest reliability for all subtests within the GRASSP range from 0.84 to 0.96 and from 0.86 to 0.98, respectively. The GRASSP is approximately 50% more sensitive (construct validity) than the International Standards of Neurological Classification of SCI (ISNCSCI) in defining sensory and motor integrity of the upper limb. The subtests show concurrence with the Spinal Cord Independence Measure (SCIM), SCIM self-care subscales, and Capabilities of Upper Extremity Questionnaire (CUE) (the strongest concurrence to impairment is with self-perception of function [CUE], 0.57-0.83, p rehabilitation, and outpatient clinics.

  9. Grip strength measured by high precision dynamometry in healthy subjects from 5 to 80 years.

    Science.gov (United States)

    Hogrel, Jean-Yves

    2015-06-10

    Grip strength is a variable which may be important to measure and follow in various populations. A new dynamometer with high accuracy and sensitivity has recently been developed to assess grip strength. The objectives of this work were to provide norms of maximal isometric grip strength measured with this new dynamometer (the MyoGrip device), to assess the reliability of measurements, to compare the measurements obtained with MyoGrip and Jamar dynamometers and finally to establish predictive equations from a population of healthy subjects (children and adults). Measurements of maximal isometric grip strength using the MyoGrip and the Jamar (which is considered as the gold-standard) were performed on 346 healthy subjects aged from 5 to 80 years. Test-retest reliability for both devices was assessed on 77 subjects. Predictive equations were computed on subjects younger than 60 years of age in order to avoid the effects of aging on strength. This study provides norms for isometric grip strength for health subjects from 5 to 80 years. Reliability of the MyoGrip device was excellent (intraclass correlation coefficient: 0.967). Despite good correlation between devices, the Jamar tended to overestimate maximal grip strength by about 14 %. A single predictive equation for men and women, adults and children incorporating hand circumference only can be used to compute the predicted theoretical maximal grip strength. The MyoGrip device is a reliable tool for measuring isometric grip strength. Owing to its unique metrological features, it can be used in very weak patients or in any situation where high precision and accuracy are required.

  10. Evolution of Durable High-Strength Flowable Mortar Reinforced with Hybrid Fibers

    OpenAIRE

    Dawood, Eethar Thanon; Ramli, Mahyuddin

    2012-01-01

    The production and use of durable materials in construction are considered as one of the most challenging things for the professional engineers. Therefore, this research was conducted to investigate the mechanical properties and the durability by using of different percentages of steel fiber with high-strength flowable mortar (HSFM) and also the use of the hybridization of steel fibers, palm fibers, and synthetic fiber (Barchip). Different experimental tests (compressive strength, splitting t...

  11. Prediction of fire spalling in fibre-reinforced high strength concrete

    Directory of Open Access Journals (Sweden)

    Mugume R.B.

    2013-09-01

    Full Text Available This paper presents results of a study which investigates spalling in small scale specimens of fibre-reinforced high strength concrete exposed to elevated temperatures. A relationship to predict relative maximum pressures was developed, which takes into account parameters such as concrete strength, fibre type and fibre geometry. Also, a blowtorch spalling test method was utilized to investigate spalling in small scale specimens, and a clear relationship between relative maximum pore pressures and spalling was observed.

  12. Leadership Strategies in Implementation of High-School Standards-Based Grading Systems

    Science.gov (United States)

    Pritzl, Jerome

    2016-01-01

    This multi-site case study examined leadership strategies used during successful implementation of standards-based grading systems in three Wisconsin high schools. It found that leaders' reported commitment, patience, and persistence showed evidence of sustainable, high-functioning systems. It drew two main conclusions: first, school leaders need…

  13. Disentangling the Predictive Validity of High School Grades for Academic Success in University

    Science.gov (United States)

    Vulperhorst, Jonne; Lutz, Christel; de Kleijn, Renske; van Tartwijk, Jan

    2018-01-01

    To refine selective admission models, we investigate which measure of prior achievement has the best predictive validity for academic success in university. We compare the predictive validity of three core high school subjects to the predictive validity of high school grade point average (GPA) for academic achievement in a liberal arts university…

  14. Closer to the Finish Line? Compulsory Attendance, Grade Attainment, and High School Graduation

    Science.gov (United States)

    Moussa, Wael S.

    2017-01-01

    High school graduation rates are a central policy topic in the United States and have been shown to be stagnant for the past three decades. Using student-level administrative data from New York City Public Schools, I examine the impact of compulsory school attendance on high school graduation rates and grade attainment, focusing the analysis on…

  15. Flexural Strength Evaluation of Reinforced Concrete Members with Ultra High Performance Concrete

    Directory of Open Access Journals (Sweden)

    Baek-Il Bae

    2016-01-01

    Full Text Available Flexural strength evaluation models for steel fiber reinforced ultra high strength concrete were suggested and evaluated with test results. Suggested flexural strength models were composed of compression stress blocks and tension stress blocks. Rectangular stress block, triangular stress block, and real distribution shape of stress were used on compression side. Under tension, rectangular stress block distributed to whole area of tension side and partial area of tension side was used. The last model for tension side is realistic stress distribution. All these models were verified with test result which was carried out in this study. Test was conducted by four-point loading with 2,000 kN actuator for slender beam specimen. Additional verifications were carried out with previous researches on flexural strength of steel fiber reinforced concrete or ultra high strength concrete. Total of 21 test specimens were evaluated. As a result of comparison for flexural strength of section, neutral axis depth at ultimate state, models with triangular compression stress block, and strain-softening type tension stress block can be used as exact solution for ultra high performance concrete. For the conservative and convenient design of section, modified rectangular stress block model can be used with strain softening type tension stress block.

  16. Crystallization of high-strength nano-scale leucite glass-ceramics.

    Science.gov (United States)

    Theocharopoulos, A; Chen, X; Wilson, R M; Hill, R; Cattell, M J

    2013-11-01

    Fine-grained, high strength, translucent leucite dental glass-ceramics are synthesized via controlled crystallization of finely milled glass powders. The objectives of this study were to utilize high speed planetary milling of an aluminosilicate glass for controlled surface crystallization of nano-scale leucite glass-ceramics and to test the biaxial flexural strength. An aluminosilicate glass was synthesized, attritor or planetary milled and heat-treated. Glasses and glass-ceramics were characterized using particle size analysis, X-ray diffraction and scanning electron microscopy. Experimental (fine and nanoscale) and commercial (Ceramco-3, IPS Empress Esthetic) leucite glass-ceramics were tested using the biaxial flexural strength (BFS) test. Gaussian and Weibull statistics were applied. Experimental planetary milled glass-ceramics showed an increased leucite crystal number and nano-scale median crystal sizes (0.048-0.055 μm(2)) as a result of glass particle size reduction and heat treatments. Experimental materials had significantly (p0.05) strength difference. All other groups' mean BFS and characteristic strengths were found to be significantly different (pceramics with high flexural strength. These materials may help to reduce problems associated with brittle fracture of all-ceramic restorations and give reduced enamel wear. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. Development and Performance Evaluation of Very High Early Strength Geopolymer for Rapid Road Repair

    Directory of Open Access Journals (Sweden)

    Abideng Hawa

    2013-01-01

    Full Text Available High early strength is the most important property of pavement repair materials to allow quick reopening to traffic. With this in mind, we have experimentally investigated geopolymers using low cost raw materials available in Thailand. The geopolymer mortar was metakaolin (MK, mixed with parawood ash (PWA, rubberwood ash or oil palm ash (OPA as binder agent. Rubberwood is often used as raw material for biomass power plants in Thailand, especially at latex glove factories and seafood factories, and burning rubberwood generates PWA. Both PWA and OPA are therefore low cost residual waste, locally available in mass quantities. The geopolymer samples were characterized for compressive strength, drying shrinkage, and bond strength to Portland cement mortar with slant shear test. The experimental design varied the contents of PWA and OPA and the heat curing time (1, 2 and 4 h after hot mixture process. The hot mixture process resulted in very high early strength. In addition, we achieved high compressive strengths, low drying shrinkage, and very significant bond strength enhancement by use of the ashes.

  18. Synthesis of high-strength microcrystalline cellulose hydrogel by viscosity adjustment.

    Science.gov (United States)

    Choe, Deokyeong; Kim, Young Min; Nam, Jae Eun; Nam, Keonwook; Shin, Chul Soo; Roh, Young Hoon

    2018-01-15

    Developing hydrogels with enhanced mechanical strength is desirable for bio-related applications. For such applications, cellulose is a notable biopolymer for hydrogel synthesis due to its inherent strength and stiffness. Here, we report the viscosity-adjusted synthesis of a high-strength hydrogel through the physical entanglement of microcrystalline cellulose (MCC) in a solvent mixture of tetrabutylammonium fluoride/dimethyl sulfoxide (TBAF/DMSO). MCC was strategically dissolved with TBAF in DMSO at a controlled ratio to induce the formation of a liquid crystalline phase (LCP), which was closely related to the viscosity of the cellulose solution. The highest viscosity was obtained at 2.5% MCC and 3.5% TBAF, leading to the strongest high-strength MCC hydrogel (strongest HS-MCC hydrogel). The resulting hydrogel exhibited a high compressive strength of 0.38MPa and a densely packed structure. Consequently, a positive linear correlation was determined between the viscosity of the cellulose solution and the mechanical strength of the HS-MCC hydrogel. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Quantitative genome-wide methylation analysis of high-grade non-muscle invasive bladder cancer.

    Science.gov (United States)

    Kitchen, Mark O; Bryan, Richard T; Emes, Richard D; Glossop, John R; Luscombe, Christopher; Cheng, K K; Zeegers, Maurice P; James, Nicholas D; Devall, Adam J; Mein, Charles A; Gommersall, Lyndon; Fryer, Anthony A; Farrell, William E

    2016-03-03

    High-grade non-muscle invasive bladder cancer (HG-NMIBC) is a clinically unpredictable disease with greater risks of recurrence and progression relative to their low-intermediate-grade counterparts. The molecular events, including those affecting the epigenome, that characterize this disease entity in the context of tumor development, recurrence, and progression, are incompletely understood. We therefore interrogated genome-wide DNA methylation using HumanMethylation450 BeadChip arrays in 21 primary HG-NMIBC tumors relative to normal bladder controls. Using strict inclusion-exclusion criteria we identified 1,057 hypermethylated CpGs within gene promoter-associated CpG islands, representing 256 genes. We validated the array data by bisulphite pyrosequencing and examined 25 array-identified candidate genes in an independent cohort of 30 HG-NMIBC and 18 low-intermediate-grade NMIBC. These analyses revealed significantly higher methylation frequencies in high-grade tumors relative to low-intermediate-grade tumors for the ATP5G2, IRX1 and VAX2 genes (P<0.05), and similarly significant increases in mean levels of methylation in high-grade tumors for the ATP5G2, VAX2, INSRR, PRDM14, VSX1, TFAP2b, PRRX1, and HIST1H4F genes (P<0.05). Although inappropriate promoter methylation was not invariantly associated with reduced transcript expression, a significant association was apparent for the ARHGEF4, PON3, STAT5a, and VAX2 gene transcripts (P<0.05). Herein, we present the first genome-wide DNA methylation analysis in a unique HG-NMIBC cohort, showing extensive and discrete methylation changes relative to normal bladder and low-intermediate-grade tumors. The genes we identified hold significant potential as targets for novel therapeutic intervention either alone, or in combination, with more conventional therapeutic options in the treatment of this clinically unpredictable disease.

  20. Genome-wide methylation profiling identifies hypermethylated biomarkers in high-grade cervical intraepithelial neoplasia.

    Science.gov (United States)

    Lendvai, Ágnes; Johannes, Frank; Grimm, Christina; Eijsink, Jasper J H; Wardenaar, René; Volders, Haukeline H; Klip, Harry G; Hollema, Harry; Jansen, Ritsert C; Schuuring, Ed; Wisman, G Bea A; van der Zee, Ate G J

    2012-11-01

    Epigenetic modifications, such as aberrant DNA promoter methylation, are frequently observed in cervical cancer. Identification of hypermethylated regions allowing discrimination between normal cervical epithelium and high-grade cervical intraepithelial neoplasia (CIN2/3), or worse, may improve current cervical cancer population-based screening programs. In this study, the DNA methylome of high-grade CIN lesions was studied using genome-wide DNA methylation screening to identify potential biomarkers for early diagnosis of cervical neoplasia. Methylated DNA Immunoprecipitation (MeDIP) combined with DNA microarray was used to compare DNA methylation profiles of epithelial cells derived from high-grade CIN lesions with normal cervical epithelium. Hypermethylated differentially methylated regions (DMRs) were identified. Validation of nine selected DMRs using BSP and MSP in cervical tissue revealed methylation in 63.2-94.7% high-grade CIN and in 59.3-100% cervical carcinomas. QMSP for the two most significant high-grade CIN-specific methylation markers was conducted exploring test performance in a large series of cervical scrapings. Frequency and relative level of methylation were significantly different between normal and cancer samples. Clinical validation of both markers in cervical scrapings from patients with an abnormal cervical smear confirmed that frequency and relative level of methylation were related with increasing severity of the underlying CIN lesion and that ROC analysis was discriminative. These markers represent the COL25A1 and KATNAL2 and their observed increased methylation upon progression could intimate the regulatory role in carcinogenesis. In conclusion, our newly identified hypermethylated DMRs represent specific DNA methylation patterns in high-grade CIN lesions and are candidate biomarkers for early detection.

  1. Evaluation of the stress corrosion cracking resistance of several high strength low alloy steels

    Science.gov (United States)

    Humphries, T. S.; Nelson, E. E.

    1980-01-01

    The stress corrosion cracking resistance was studied for high strength alloy steels 4130, 4340, for H-11 at selected strength levels, and for D6AC and HY140 at a single strength. Round tensile and C-ring type specimens were stressed up to 100 percent of their yield strengths and exposed to alternate immersion in salt water, salt spray, the atmosphere at Marshall Space Flight Center, and the seacoast at Kennedy Space Center. Under the test conditions, 4130 and 4340 steels heat treated to a tensile strength of 1240 MPa (180 ksi), H-11 and D6AC heat treated to a tensile strength of 1450 MPa (210 ksi), and HY140 (1020 MPa, 148 ksi) are resistant to stress corrosion cracking because failures were not encountered at stress levels up to 75 percent of their yield strengths. A maximum exposure period of one month for alternate immersion in salt water or salt spray and three months for seacoast is indicated for alloy steel to avoid false indications of stress corrosion cracking because of failure resulting from severe pitting.

  2. Histologic variation in high grade oral epithelial dysplasia when associated with high-risk human papillomavirus.

    Science.gov (United States)

    Khanal, Sujita; Trainor, Patrick J; Zahin, Maryam; Ghim, Shin-Je; Joh, Joongho; Rai, Shesh N; Jenson, Alfred Bennett; Shumway, Brian S

    2017-05-01

    Reported cytologic alterations associated with high-risk human papillomavirus (HR-HPV) in oral epithelial dysplasia (HPV-OED) need further characterization. Archival cases of high-grade oral epithelial dysplasia (hgOED) (N = 38) were assigned a cytologic score (CS) based on the average number of mitotic, karyorrhectic, and apoptotic cells per high-power field. Three groups were then generated on the basis of increasing CS: Focal (group 1, N = 14), Intermediate (group 2, N = 12), and Diffuse (group 3, N = 12). Polymerase chain reaction-based HPV genotyping and p16 immunohistochemistry were performed. HR-HPV was found significantly more in group 3 (83.3%) compared with groups 1 and 2 (group 1&2; 42.9% and 41.7%, respectively; P = .047). HPV16 predominated in HR-HPV-positive cases (90.5%). By location, the tongue or the floor of mouth was associated with all groups (P = .04). Increasing CS was associated with a slightly younger age (P = .04) and increased expression of p16 (P = .005). CS and p16 expression were not sensitive but were highly specific predictors for HR-HPV presence. Based on limited follow-up information, HPV-OED does not differ in clinical aggressiveness compared with conventional OED. Increased CS in hgOED is strongly associated with HR-HPV (mostly HPV16) and p16 expression. CS and p16 expression are specific predictors of HR-HPV presence. Further molecular study and long-term follow-up of HPV-OED are needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on tunable functionalized copolymers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Daugaard, Anders Egede

    2015-01-01

    system, with respect to functionalization, is achieved. It is investigated how the different functionalization variables affect essential DE properties, including dielectric permittivity, dielectric loss, elastic modulus and dielectric breakdown strength, and the optimal degree of chemical......%) was obtained without compromising other vital DE properties such as elastic modulus, gel fraction, dielectric and viscous loss and electrical breakdown strength....

  4. High-capacity, high-strength trailer designs for the GA-4/GA-9 casks

    International Nuclear Information System (INIS)

    Rickard, N.D.; Kissinger, J.A.; Taylor, C.; Zimmer, A.

    1991-01-01

    General Atomics (GA) is developing final designs for two dedicated legal-weight trailers to transport the GA-4 and GA-9 Spent-Fuel Casks. The basic designs for these high-capacity, high-strength trailers are essentially identical except for small modifications to account for the differences in cask geometry. The authors are designing both trailers to carry a 55,000 lb (24,900 kg) payload and to withstand a 2.5 g vertical design load. The GA-4 and GA-9 trailers are designed for significantly higher loads than are typical commercial semitrailers, which are designed to loads in the range of 1.7 to 2.0 g. To meet the federal gross vehicle weight limit for legal-weight trucks, GA has set a target design weight for the trailers of 9000 lb (4080 kg). This weight includes the personnel barrier, cask tiedowns, and impact limiter removal and storage system. Based on the preliminary trailer designs, the final design weight will to be very close to this target weight

  5. An Investigation on Fatigue in High-Strength Steel Offshore Structures

    DEFF Research Database (Denmark)

    Agerskov, Henning; Petersen, R.I.; Lopez Martinez, L.

    1997-01-01

    In the present investigation, the fatigue life of offshore steel structures in high-strength steel is studied. The material used has a yield stress of 800-1000 MPa, and high weldability and toughness properties. Of special interest is the fatigue life under a realistic stochastic loading....... In the experimental part of the investigation, fatigue test series have been carried through on both full-scale tubular joints and smaller welded plate test specimens, in high-strength steel as well as in conventional offshore structural steel. The present document gives a summary of the main results presented in two......, in general longer fatigue lives were obtained for the test specimens in high-strength steel than those obtained in corresponding tests on joints in conventional offshore structural steel....

  6. Fatigue in Welded High-Strength Steel Plate Elements under Stochastic Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning; Petersen, R.I.; Martinez, L. Lopez

    1999-01-01

    The present project is a part of an investigation on fatigue in offshore structures in high-strength steel. The fatigue life of plate elements with welded attachments is studied. The material used has a yield stress of ~ 810-840 MPa, and high weldability and toughness properties. Fatigue test...... series with constant amplitude loading and with various types of stochastic loading have been carried through on test specimens in high-strength steel, and - for a comparison - on test specimens in conventional offshore structural steel with a yield stress of ~ 400-410 MPa.A comparison between constant...... amplitude and variable amplitude fatigue test results shows shorter fatigue lives in variable amplitude loading than should be expected from the linear fatigue damage accumulation formula. Furthermore, in general longer fatigue lives were obtained for the test specimens in high-strength steel than those...

  7. An investigation on fatigue in high-strength steel offshore structures

    DEFF Research Database (Denmark)

    Agerskov, Henning; Petersen, R.I.; Martinez, L. Lopez

    1998-01-01

    The fatigue life of offshore steel structures in high-strength steel is studied. The material used has a yield stress of 800-1000 MPa and high weldability and toughness properties. Of special interest is the fatigue life under a realistic stochastic loading. In the experimental part...... of the investigation, fatigue test series were carried out on both full scale tubular joints and smaller welded plate test specimens in high-strength steel as well as in conventional offshore structural steel. This paper gives a summary of the main results presented in two recent research reports [15, 16], from...... specimens in high-strength steel than those obtained in corresponding tests on joints in conventional offshore structural steel....

  8. Present Status and Prospect of Ultra High Strength Steel Applied to Aircraft Landing Gear

    Directory of Open Access Journals (Sweden)

    ZHAO Bo

    2017-12-01

    Full Text Available The paper presents the domestic and overseas current status of the steel applied to aircraft landing gear in combination of the design concept and requirements for aircraft landing gear. The application features and concept of the steel used for landing gear are summarized and the domestic and overseas status are compared. For the moment, the low-alloy ultra-high strength steel and high-alloy ultra-high strength steel are all being used in the material system for aircraft landing gear steel, and the complete technical system for its anti-fatigue manufacturing is built. At present, China's development and application of high strength steel applied to aircraft landing gear is at the world advanced level. At last, the prospect for future development is analyzed.

  9. EXPERIMENTAL TESTS OF VANADIUM STRENGTH MODELS AT HIGH PRESSURES AND STRAIN RATES

    Energy Technology Data Exchange (ETDEWEB)

    Park, H; Barton, N R; Becker, R C; Bernier, J V; Cavallo, R M; Lorenz, K T; Pollaine, S M; Remington, B A; Rudd, R E

    2010-03-02

    Experimental results showing significant reductions from classical in the Rayleigh-Taylor (RT) instability growth rate due to high pressure material strength or effective lattice viscosity in metal foils are presented. On the Omega Laser in the Laboratory for Laser Energetics, University of Rochester, target samples of polycrystalline vanadium are compressed and accelerated quasi-isentropically at {approx}1 Mbar pressures, while maintaining the samples in the solid-state. Comparison of the results with constitutive models for solid state strength under these conditions show that the measured RT growth is substantially lower than predictions using existing models that work well at low pressures and long time scales. High pressure, high strain rate data can be explained by the enhanced strength due to a phonon drag mechanism, creating a high effective lattice viscosity.

  10. High-strength bioresorbable Fe-Ag nanocomposite scaffolds: Processing and properties

    Science.gov (United States)

    Sharipova, Aliya; Psakhie, Sergey G.; Swain, Sanjaya K.; Gutmanas, Elazar Y.; Gotman, Irena

    2015-10-01

    High strength ductile iron-silver nanocomposite scaffolds were fabricated employing high energy attrition milling of micron-submicron powders, followed by cold sintering/high pressure consolidation. Particulate leaching method with soluble Na2SO4 and K2CO3 salts as porogens was used to create scaffolds with 50, 55, 60 and 73% volume fraction of pores. Part of specimens was annealed at 600, 800 and 900°C. Specimens were characterized employing X-ray diffraction, scanning electron microscopy (SEM) with electron probe microanalysis (EDS) and high resolution SEM. Mechanical properties were measured in compression and permeability was measured in permeameter based on Darcy's law. Scaffolds with 50% and 55% porosity exhibited high compressive strength (18-22 MPa), compressive strength of 8-12 MPa was observed for scaffolds with 73% porosity. Treatments at 800 and 900°C result in increase of strength and ductility with some coarsening of microstructure. Best combination of compressive strength (15 MPa) and permeability (0.6-6 cm2) is close to the range of trabecular bone.

  11. Identifying patients at risk for high-grade intra-abdominal hypertension following trauma laparotomy.

    Science.gov (United States)

    Strang, Steven G; Van Imhoff, Diederik L; Van Lieshout, Esther M M; D'Amours, Scott K; Van Waes, Oscar J F

    2015-05-01

    Abdominal Compartment Syndrome (ACS) is an uncommon but deleterious complication after trauma laparotomy. Early recognition of patients at risk of developing ACS is crucial for their outcome. The aim of this study was to compare the characteristics of patients who developed high-grade intra-abdominal hypertension (IAH) (i.e., grade III or IV; intra-abdominal pressure, IAP >20 mm Hg) following an injury-related laparotomy versus those who did not (i.e., IAP ≤20 mm Hg). A retrospective analysis of consecutive trauma patients admitted to a level 1 trauma centre in Australia between January 1, 1995 and January 31, 2010 was performed. A comparison was made between characteristics of patients who developed high-grade IAH following trauma laparotomy versus those who did not. A total of 567 patients (median age 31 years) were included in this study. Of these patients 10.2% (58/567) developed high-grade IAH of which 51.7% (30/58) developed ACS. Patients with high-grade IAH were older (pgrade IAH received larger volumes of crystalloids (pgrade IAH suffered higher mortality rates (25.9% (15/58) vs. 12.2% (62/509); p=0.012). Of all patients who underwent a trauma laparotomy, 10.2% developed high-grade IAH, which increases the risk of mortality. Patients with acidosis, coagulopathy, and hypothermia were especially at risk. In these patients, the abdomen should be left open until adequate resuscitation has been achieved, allowing for definitive surgery. This is a level III retrospective study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Risk factors for high-grade envenomations after French viper bites in children.

    Science.gov (United States)

    Claudet, Isabelle; Maréchal, Céline; Gurrera, Emmanuel; Cordier, Laurie; Honorat, Raphaele; Grouteau, Erick

    2012-07-01

    Viper bites and subsequent evolution to severe envenomations are more frequent in children. The aims of this study were to describe the clinical, biological, and therapeutic characteristics of children bitten by vipers in France and to identify risk factors associated with severe envenomations. A retrospective study was conducted between 2001 and 2009 in the pediatric emergency department of a tertiary-level children hospital. Collected data were age and sex of children; day and time of admission; day, time, and circumstances of the accident; snake identification; bite location; envenomation severity; presence of fang marks; prehospital care; use of specific immunotherapy and associated treatments; length of stay; and hospital course. Fifty-eight children were included (43 boys, 15 girls). The mean age was 7.8 ± 4.1 years. Bites were most often located on the lower extremities (77%). The classification of envenomation was: 83% low grade (absence or minor envenomation) and 17% high-grade (moderate to severe envenomations). All high-grade envenomations received specific immunotherapy (Viperfav). Being bitten on an upper extremity (P level (P = 0.016) were associated with a significant risk of high-grade envenomation. In the multivariate analysis, 3 factors remained significant: upper-extremity location (relative risk [RR], 60.5 [3.5-1040]; P = 0.005), immediate violent pain (RR, 21.5 [1.3-364.5]; P = 0.03), and female sex (RR, 17.5 [0.9-320.3]; P = 0.053). A certain number of criteria seem related to more significant risk of progression to high-grade envenomation. Bites to the upper extremities should be carefully observed because of the risk of evolution to a high-grade envenomation.

  13. High Salt Diets, Bone Strength and Mineral Content of Mature Femur After Skeletal Unloading

    Science.gov (United States)

    Liang, Michael T. C.

    1998-01-01

    It is known that high salt diets increase urinary calcium (Ca) loss, but it is not known whether this effect weakens bone during space flight. The Bone Hormone Lab has studied the effect of high salt diets on Ca balance and whole body Ca in a space flight model (2,8). Neither the strength nor mineral content of the femurs from these studies has been evaluated. The purpose of this study was to determine the effect of high salt diets (HiNa) and skeletal unloading on femoral bone strength and bone mineral content (BMC) in mature rats.

  14. Effect of High-Grade Preoperative Knee Laxity on Anterior Cruciate Ligament Reconstruction Outcomes.

    Science.gov (United States)

    Magnussen, Robert A; Reinke, Emily K; Huston, Laura J; Hewett, Timothy E; Spindler, Kurt P

    2016-12-01

    Knee laxity in the setting of suspected anterior cruciate ligament (ACL) injury is frequently assessed through physical examination using the Lachman, pivot-shift, and anterior drawer tests. The degree of laxity noted on these examinations may influence treatment decisions and prognosis. Increased preoperative knee laxity would be associated with increased risk of subsequent revision ACL reconstruction and worse patient-reported outcomes 2 years postoperatively. Cohort study; Level of evidence, 2. From an ongoing prospective cohort study, 2333 patients who underwent primary isolated ACL reconstruction without collateral or posterior cruciate ligament injury were identified. Patients reported by the operating surgeons as having an International Knee Documentation Committee (IKDC) grade D for Lachman, anterior drawer, or pivot-shift examination were classified as having high-grade laxity. Multiple logistic regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with increased odds of undergoing revision ACL reconstruction within 2 years of the index procedure, controlling for patient age, sex, Marx activity level, level of competition, and graft type. Multiple linear regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with worse IKDC score or Knee injury and Osteoarthritis Outcome Score Knee-Related Quality of Life subscale (KOOS-QOL) scores at a minimum 2 years postoperatively, controlling for baseline score, patient age, ethnicity, sex, body mass index, marital status, smoking status, sport participation, competition level, Marx activity rating score, graft type, and articular cartilage and meniscus status. Pre-reconstruction laxity data were available for 2325 patients (99.7%). Two-year revision data were available for 2259 patients (96.8%), and patient-reported outcomes were available for 1979 patients (84.8%). High-grade preoperative laxity was noted in 743 patients

  15. The Spectrum of Triple-Negative Breast Disease: High- and Low-Grade Lesions.

    Science.gov (United States)

    Geyer, Felipe C; Pareja, Fresia; Weigelt, Britta; Rakha, Emad; Ellis, Ian O; Schnitt, Stuart J; Reis-Filho, Jorge S

    2017-10-01

    Triple-negative breast cancer is viewed clinically as an aggressive subgroup of breast cancer. In fact, most triple-negative breast cancers are poor-prognosis tumors with a complex genomic landscape. However, triple-negative disease is vastly heterogeneous, encompassing multiple entities with marked genetic, transcriptional, histologic, and clinical differences, with neoplasms in this group ranging from low to high grade. Among the less common low-grade triple-negative lesions, two large subgroups, both with a rather indolent behavior, can be distinguished: a low-grade triple-negative breast neoplasia family, which includes nonobligate precursors of triple-negative breast cancer, and, despite being low-grade, harbors the complex genomic landscape of usual triple-negative breast cancer, and the salivary gland-like tumors of the breast, lacking all the cardinal molecular features of conventional triple-negative breast cancer and underpinned by specific fusion genes or hotspot mutations, which may be of diagnostic and possibly therapeutic utility. Progression to high-grade triple-negative breast cancer likely occurs in both subgroups but at different rates. In this review, we describe the heterogeneity of triple-negative disease, focusing on the histologic and molecular features of the low-grade lesions. Recognition that triple-negative breast cancer is an operational term and that triple-negative disease is heterogeneous and includes low-grade forms driven by distinct sets of genetic alterations is germane to the successful implementation of precision medicine. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  16. Fracture and fatigue of high strength filaments. Final report, September 25, 1974--August 30, 1975

    International Nuclear Information System (INIS)

    Holt, N.L.; Finnie, I.

    1975-01-01

    The history of high strength filamentary materials is traced and it is seen that their use has been widespread. It is shown that today's demands upon these materials require a better understanding of their behavior than is presently available. Current theories for both the static and fatigue strength of filamentary materials are reviewed. An analysis of static strength tests on short filaments is presented that explains seemingly anomalous test behavior which has been reported in the literature. The proposed approach is supported by experiments and computer analysis. A new machine for the fatigue testing of filaments or wires was designed and is described in detail. Results are presented for fatigue tests on tungsten wire, graphite filaments and glass filaments. Graphite filaments showed an unexpected deterioration in strength after very many cycles (10 8 ). An explanation of this effect is offered and supported by scanning electron microscope observations. The work concludes with some suggestions for further research

  17. Shear Response of Fibrous High Strength Concrete Beams without Web Reinforcement

    Directory of Open Access Journals (Sweden)

    Gunneswara Rao, T.D.

    2011-01-01

    Full Text Available The use of steel fibers to improve the mechanical properties of concrete has been the ongoing interest in the research work. This paper deals with one such improvement in the mechanical property of concrete, which is the shear strength. In this paper an attempt has been made to study the improvement of shear strength of high strength concrete beams (70 MPa with different shear span to depth ratios (a/d = 1, 2, 3, and 4 and various dosages of fibers (0.4%, 0.8%, and 1.2% by volume of concrete, without shear reinforcement. The experimental work revealed that steel fiber volume has different influence at different shear span to depth ratios (a/d. The test results indicated an increase in the cracking shear resistance noticeably and ultimate shear strength moderately.

  18. Ultrahigh Charpy impact toughness (~450J) achieved in high strength ferrite/martensite laminated steels.

    Science.gov (United States)

    Cao, Wenquan; Zhang, Mingda; Huang, Chongxiang; Xiao, Shuyang; Dong, Han; Weng, Yuqing

    2017-02-02

    Strength and toughness are a couple of paradox as similar as strength-ductility trade-off in homogenous materials, body-centered-cubic steels in particular. Here we report a simple way to get ultrahigh toughness without sacrificing strength. By simple alloying design and hot rolling the 5Mn3Al steels in ferrite/austenite dual phase temperature region, we obtain a series of ferrite/martensite laminated steels that show up-to 400-450J Charpy V-notch impact energy combined with a tensile strength as high as 1.0-1.2 GPa at room temperature, which is nearly 3-5 times higher than that of conventional low alloy steels at similar strength level. This remarkably enhanced toughness is mainly attributed to the delamination between ferrite and martensite lamellae. The current finding gives us a promising way to produce high strength steel with ultrahigh impact toughness by simple alloying design and hot rolling in industry.

  19. Ultrahigh Charpy impact toughness (~450J) achieved in high strength ferrite/martensite laminated steels

    Science.gov (United States)

    Cao, Wenquan; Zhang, Mingda; Huang, Chongxiang; Xiao, Shuyang; Dong, Han; Weng, Yuqing

    2017-01-01

    Strength and toughness are a couple of paradox as similar as strength-ductility trade-off in homogenous materials, body-centered-cubic steels in particular. Here we report a simple way to get ultrahigh toughness without sacrificing strength. By simple alloying design and hot rolling the 5Mn3Al steels in ferrite/austenite dual phase temperature region, we obtain a series of ferrite/martensite laminated steels that show up-to 400–450J Charpy V-notch impact energy combined with a tensile strength as high as 1.0–1.2 GPa at room temperature, which is nearly 3–5 times higher than that of conventional low alloy steels at similar strength level. This remarkably enhanced toughness is mainly attributed to the delamination between ferrite and martensite lamellae. The current finding gives us a promising way to produce high strength steel with ultrahigh impact toughness by simple alloying design and hot rolling in industry. PMID:28150692

  20. Misconceptions Analysis on The Virus Chapter in Biology Textbooks for High School Students Grade X

    Directory of Open Access Journals (Sweden)

    Dyah Ayu Febrianna Saputri

    2016-11-01

    Full Text Available Source of learning is something that can not be separated from the learning activities. One source of learning is learning materials. The book is one example of teaching materials from learning resources. The book is one source of information for learning. Problems often occur in the textbook is a misconceptions. This study aimed to analyze misconceptions on the virus chapter in biology textbook grade X. This research is a qualitative descriptive study provides the interpretation of data obtained in a rational and objective. This research subject is the content of the biology textbook for high school students grade X. While the object under study is the truth of the concept virus chapter biology textbook for high school students grade X. The results showed that the textbooks studied Biology class X are misconceptions which are divided into five categories, namely Misidentifications, Overgeneralizations, Oversimplications, Obsolete Concept and Terms and Undergeneralizations. Percentage of misconceptions found in every of biology textbook students grade X on the virus chapter that is 11.10% on the textbook A; 21.05% on the textbook B; and 31.03% on the textbook C. Criteria misconceptions most commonly found on the virus chapter in biology textbook students grade X is Oversimplications as much as 36.73%.

  1. Utilization of Local Ingredients for the Production of High-Early-Strength Engineered Cementitious Composites

    Directory of Open Access Journals (Sweden)

    Hanwen Deng

    2018-01-01

    Full Text Available The rapid repair and retrofitting of existing transportation infrastructure requires dimensional stability and ductile repair material that can obtain sufficiently high strength in a few hours to accommodate the large loading and deformation at an early age. Engineering cementitious composites (ECCs is a class representative of the new generation of high-performance fiber-reinforced cement-based composites (HPFRCC with medium fiber content. The unique properties of tremendous ductility and tight multiple crack behavior indicate that ECC can be used as an effective retrofit material. The wide application of this material in China will require the use of all local ingredients. In this study, based on Chinese domestic ingredients, including matrix materials and all fibers, high-early-strength ECC (HES-ECC was designed under the guidance of strain-hardening criterion of ECC. The matrix properties and fiber/matrix interfacial micromechanics properties were obtained from three-point-bending test and single-fiber pullout test. The mechanical properties of HES-ECC were achieved by direct tensile test. The experimental results show that HES-ECC was successfully developed by using all Chinese materials. When using the domestic PVA fiber at 2%, the strength requirement can be achieved but only a low ductility. When using the domestic PE fiber at 0.8%, the strength and deformation requirement both can be obtained. The HES-ECC developed in this study exhibited compressive strength of more than 25 MPa within 6 hours, and an ultimate tensile strength of 5-6 MPa and tensile strain capacity of 3-4% after 60 days. Moreover, the cost of using domestic fiber can be largely reduced compared with using imported fiber, up to 70%; it is beneficial to the promotion of these high-early-strength ECCs in the Chinese market.

  2. Production of high strength concrete by use of industrial by-products

    Energy Technology Data Exchange (ETDEWEB)

    Demirboga, Ramazan; Guel, Ruestem [Civil Engineering Department, Engineering Faculty, Atatuerk University, 25240- Erzurum (Turkey)

    2006-08-15

    Blast furnace slag aggregates (BFSA) were used to produce high-strength concretes (HSC). These concretes were made with total cementitious material content of 460-610kg/m{sup 3}. Different water/cement ratios (0.30, 0.35, 0.40, 0.45 and 0.50) were used to carry out 7- and 28-day compressive strength and other properties. Silica fume and a superplasticizer were used to improve BFSA concretes. Slump was kept constant throughout this study. Ten percent silica fume was added as a replacement for ordinary portland cement (OPC) in order to obtain HSC. The silica fume was used as highly effective micro-filler and pozzolanic admixture. Superplasticizer at dosages of 2%, 1.5%, 1%, 0.5% and 0% by OPC weight for 0.30, 0.35, 0.40, 0.45 and 0.50 w/c ratios, respectively, were adopted. Results showed that compressive strength of BFSA concretes were approximately 60-80% higher than traditional (control) concretes for different w/c ratios. These concretes also had low absorption and high splitting tensile strength values. It is concluded that BFSA, in combination with other supplementary cementitious materials, can be utilized in making high strength concretes. (author)

  3. Effect of tension lap splice on the behavior of high strength concrete (HSC beams

    Directory of Open Access Journals (Sweden)

    Ahmed El-Azab

    2014-12-01

    Full Text Available In the recent years, many research efforts have been carried out on the bond strength between normal strength concrete (NSC and reinforcing bars spliced in tension zones in beams. Many codes gave a minimum splice length for tension and compression reinforcement as a factor of the bar diameter depending on many parameters such as concrete strength, steel yield stress, shape of bar end, shape of bar surface and also bar location. Also, codes gave another restriction about the percentage of total reinforcement to be spliced at the same time. Comparatively limited attention has been directed toward the bond between high strength concrete (HSC and reinforcing bars spliced in tension zones in beams. HSC has high modulus of elasticity, high density and long-term durability. This research presents an experimental study on the bond between high strength concrete (HSC and reinforcing bars spliced in tension zones in beams. It reports the influence of several parameters on bond in splices. The parameters covered are casting position, splice length as a factor of bar diameter, bar diameter and reinforcement ratio. The research involved tests on sixteen simply-supported beams of 1800 mm span, 200 mm width and 400 mm thickness made of HSC. In each beam, the total tensile steel bars were spliced in the constant moment zone. Crack pattern, crack propagation, cracking load, failure load and mi span deflection were recorded and analyzed to study the mentioned parameters effect.

  4. Hydration and muscular performance: does fluid balance affect strength, power and high-intensity endurance?

    Science.gov (United States)

    Judelson, Daniel A; Maresh, Carl M; Anderson, Jeffrey M; Armstrong, Lawrence E; Casa, Douglas J; Kraemer, William J; Volek, Jeff S

    2007-01-01

    Significant scientific evidence documents the deleterious effects of hypohydration (reduced total body water) on endurance exercise performance; however, the influence of hypohydration on muscular strength, power and high-intensity endurance (maximal activities lasting >30 seconds but physiological demands of strength, power and high-intensity endurance couple with a lack of scientific support to argue against previous hypotheses that suggest alterations in cardiovascular, metabolic and/or buffering function represent the performance-reducing mechanism of hypohydration. On the other hand, hypohydration might directly affect some component of the neuromuscular system, but this possibility awaits thorough evaluation. A critical review of the available literature suggests hypohydration limits strength, power and high-intensity endurance and, therefore, is an important factor to consider when attempting to maximise muscular performance in athletic, military and industrial settings.

  5. Statistical approach to predict compressive strength of high workability slag-cement mortars

    International Nuclear Information System (INIS)

    Memon, N.A.; Memon, N.A.; Sumadi, S.R.

    2009-01-01

    This paper reports an attempt made to develop empirical expressions to estimate/ predict the compressive strength of high workability slag-cement mortars. Experimental data of 54 mix mortars were used. The mortars were prepared with slag as cement replacement of the order of 0, 50 and 60%. The flow (workability) was maintained at 136+-3%. The numerical and statistical analysis was performed by using database computer software Microsoft Office Excel 2003. Three empirical mathematical models were developed to estimate/predict 28 days compressive strength of high workability slag cement-mortars with 0, 50 and 60% slag which predict the values accurate between 97 and 98%. Finally a generalized empirical mathematical model was proposed which can predict 28 days compressive strength of high workability mortars up to degree of accuracy 95%. (author)

  6. Deterioration of mechanical properties of high strength structural steel S460N under transient state fire condition

    International Nuclear Information System (INIS)

    Qiang, Xuhong; Bijlaard, Frans S.K.; Kolstein, Henk

    2012-01-01

    Highlights: ► Mechanical properties of S460N under transient state fire condition are obtained. ► Elevated-temperature mechanical properties of steels are dependent on steel grades. ► No design standard is applicable to HSS S460N under transient state fire condition. ► Specific statements on various HSS in fire should be proposed in design standards. ► Research results offer accurate material property for structural design engineers. -- Abstract: 911 World Trade Centre Tragedy put fire safety of constructional steel structures into question. Since then, more and more research attention has been paid to the elevated-temperature mechanical properties of structural steels, which is a critical basis of evaluating the fire performance of steel structures. In the literature the available mechanical properties of structural steels under fire conditions were mainly obtained from steady state test method, as steady state test method is easier to perform than transient state test method and offers stress–strain curves directly. However, the transient state fire condition is considered to be more realistic to represent the real condition when constructions are exposed to fire. In order to reveal the deterioration of mechanical properties of the commonly used high strength structural steel S460N under transient state fire condition, tensile tests were conducted under various constant stress levels up to 800 MPa. The reduction factors of elastic modulus, yield and ultimate strengths of S460N under transient state fire condition were obtained and compared with current leading design standards and available literature. The application of such accurate elevated-temperature mechanical properties reduction factors of S460N can ensure a safe fire-resistance design and evaluation of steel structures with high strength steel S460N under transient state fire condition. This experimental study also supports other relative research on fire performance of steel structures with

  7. Predicting Freshman Grade Point Average From College Admissions Test Scores and State High School Test Scores

    OpenAIRE

    Koretz, Daniel; Yu, C; Mbekeani, Preeya Pandya; Langi, M.; Dhaliwal, Tasminda Kaur; Braslow, David Arthur

    2016-01-01

    The current focus on assessing “college and career readiness” raises an empirical question: How do high school tests compare with college admissions tests in predicting performance in college? We explored this using data from the City University of New York and public colleges in Kentucky. These two systems differ in the choice of college admissions test, the stakes for students on the high school test, and demographics. We predicted freshman grade point average (FGPA) from high school GPA an...

  8. Recurrent high-grade meningioma: a phase II trial with somatostatin analogue therapy.

    Science.gov (United States)

    Simó, Marta; Argyriou, Andreas A; Macià, Miquel; Plans, Gerard; Majós, Carles; Vidal, Noemi; Gil, Miguel; Bruna, Jordi

    2014-05-01

    A prospective, two-stage phase II trial with octreotide in patients with recurrent high-grade meningioma was conducted. The radiographic partial response (RPR) was set as the primary study endpoint, whereas progression-free survival at 6 months (PFS6) was defined as the secondary endpoint. Nine patients (eight men; median age 65) with histological high-grade meningioma (five with grade II and four with grade III) and progression after prior surgery and radiotherapy were included. All had positive brain octreotide SPECT scanning. Octreotide was administered intramuscularly once every 28 days at a dose of 30 mg for the first two cycles and 40 mg for subsequent cycles until progression. Magnetic resonance imaging was performed every 3 months. Progression and RPR were defined as an increase of ≥25 % and as a decrease of ≥50 % in two-dimensional maximum diameters, respectively. Patients received a median of three octreotide cycles (range 1-8) without grade ≥2 toxicities. No RPRs were observed. Stable disease was the best response in 33.3 % (n = 3). All patients had progressive disease at 10 months of follow-up. Median time to progression was 4.23 months (range 1-9.4), and the PFS6 was 44.4 % (n = 4). Our study failed to provide evidence to support the use of monthly long-acting somatostatin analogue schedule in recurrent high-grade meningiomas, as none of our patients demonstrated RPR. The modest median PFS of 4-5 months along with the unknown natural history of recurrent meningiomas render the use of this therapy against these aggressive brain tumors uncertain.

  9. Supporting Young Adolescents' Middle-to-High-School Transition by Creating a Ninth Grade Community of Care: Implications for Middle Grades Educators

    Science.gov (United States)

    Ellerbrock, Cheryl R.; Kiefer, Sarah M.

    2014-01-01

    The middle-to-high-school transition and the first year of high school are critical periods in students' lives. According to the Southern Regional Education Board (SREB), "The passage of students from the middle grades to high school is the most difficult transition point in education" (2002, p. 24). Although there are many different…

  10. Coseismic landslides reveal near-surface rock strength in a high-relief tectonically active setting

    Science.gov (United States)

    Gallen, Sean F.; Clark, Marin K.; Godt, Jonathan W.

    2014-01-01

    We present quantitative estimates of near-surface rock strength relevant to landscape evolution and landslide hazard assessment for 15 geologic map units of the Longmen Shan, China. Strength estimates are derived from a novel method that inverts earthquake peak ground acceleration models and coseismic landslide inventories to obtain material proper- ties and landslide thickness. Aggregate rock strength is determined by prescribing a friction angle of 30° and solving for effective cohesion. Effective cohesion ranges are from 70 kPa to 107 kPa for 15 geologic map units, and are approximately an order of magnitude less than typical laboratory measurements, probably because laboratory tests on hand-sized specimens do not incorporate the effects of heterogeneity and fracturing that likely control near-surface strength at the hillslope scale. We find that strength among the geologic map units studied varies by less than a factor of two. However, increased weakening of units with proximity to the range front, where precipitation and active fault density are the greatest, suggests that cli- matic and tectonic factors overwhelm lithologic differences in rock strength in this high-relief tectonically active setting.

  11. Tensile strength and durability characteristics of high-performance fiber reinforced concrete

    International Nuclear Information System (INIS)

    Ramadoss, P.; Nagamani, K.

    2008-01-01

    This paper presents investigations towards developing a better understanding of the contribution of steel fibers to the tensile strength of high-performance fiber reinforced concrete (HPFRC). For 32 series of mixes, flexural and splitting tensile strengths were determined at 28 days. The variables investigated were fiber volume fraction (0%, 0.5%, 1% and 1.5% with an aspect of 80), silica fume replacement level (SF/CM=0.05 and 0.10) and matrix composition (w/cm ratios ranging from 0.25 t 0.40). The influence of fiber content in terms of fiber reinforcing index on the flexural and splitting tensile strengths of HPFRC is presented. Comparative studies were performed on the tensile behavior of SFRC measured by two different loading tests: flexural test and splitting test. Based on the test results, using the least square method, empirical expressions were developed to predict 28-day tensile strength of HPFRC in terms of fiber reinforcing index. Durability tests were carried out to examine the performance of the SFRC. Relationship between flexural and splitting tensile strengths has been developed using regression analysis. The experimental values of previous researchers were compared with the values predicted by the empirical equations and the absolute variation obtained was within 6% and 5% for flexural and splitting tensile strengths respectively. (author)

  12. [The effect of 24 weeks of moderate-to-high intensity strength training on the elderly].

    Science.gov (United States)

    Solà Serrabou, Marta; López del Amo, José Luis; Valero, Oliver

    2014-01-01

    Strength programs have been seen to be useful in minimizing the effects of sarcopenia, although intervention protocols may vary in their content and characteristics. The aim of this study was to demonstrate the influence of a particular strength protocol for the elderly. A total of 35 individuals took part in the study, with 18 in the exercise group (4 men and 14 women), and 17 in the control group (4 men and 13 women). The average age was 73. The exercise group carried out a strength training program at moderate to high intensity over 24 weeks. Strength was evaluated using the chair stand test, 2-minute step and 2 vertical jumps-squat jump (SJ), and countermovement jump (CMJ). Falls in both groups were also compared before and after the intervention, as well as their relationship with the chair stand variable. A tendency towards improvement was observed in all tests, with the exception of CMJ; while the control group showed a tendency in the opposite direction. Contrast between the two groups at the end of the intervention was notable in all the tests. An inverse relationship between the chair stand strength variable and the number of falls was evident. According to the results achieved, the training was perceived to exercise a positive influence on both the strength of the elderly people and a reduction of the number of falls. The gap between the two groups widened towards the end of the intervention. Copyright © 2013 SEGG. Published by Elsevier Espana. All rights reserved.

  13. Genetic profile of adenoid cystic carcinomas (ACC) with high-grade transformation versus solid type

    NARCIS (Netherlands)

    Costa, A.F.; Altemani, A.; Vékony, H.; Bloemena, E.; Fresno, F.; Suárez, C.; Llorente, J.L.; Hermsen, M.

    2010-01-01

    Background: ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACCHGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGTis generally considered to be an aggressive variant of ACC, even more

  14. Group Art Therapy with Eighth-Grade Students Transitioning to High School

    Science.gov (United States)

    Spier, Erin

    2010-01-01

    This study examined the effectiveness of a group art therapy intervention within a school setting to increase coping skills and decrease disruptive behaviors in a group of 6 eighth-grade students at risk for making a poor transition to high school. The mixed-method AB single-case experiment measured each individual's changes in behavior and coping…

  15. Medium-sized grazing incidence high-energy X-ray telescopes employing continuously graded multilayers

    DEFF Research Database (Denmark)

    Joensen, K. D.; Christensen, Finn Erland; Schnopper, H. W.

    1993-01-01

    The authors present a concept of continuously graded multilayer structures for medium-sized X-ray telescopes which is based on several material combinations. They show that the theoretical reflectivity characteristics of these structures make them very advantageous when applied to high energy X-r...

  16. Genetic profile of adenoid cystic carcinomas (ACC) with high-grade transformation versus solid type

    NARCIS (Netherlands)

    Costa, A.F.; Altemani, A.; Vékony, H.; Bloemena, E.; Fresno, F.; Suárez, C.; Llorente, J.L.; Hermsen, M.

    2011-01-01

    Background: ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACC-HGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGT is generally considered to be an aggressive variant of ACC, even more

  17. Survival and prognostic factors at time of diagnosis in high-grade appendicular osteosarcoma

    DEFF Research Database (Denmark)

    Colding-Rasmussen, Thomas; Thorn, Andrea Pohly; Horstmann, Peter

    2018-01-01

    BACKGROUND: Survival of patients with high-grade osteosarcoma (HOS), the most common primary bone cancer, has not improved significantly the last 30 years and the disease remains a major challenge. The purpose of this study is to evaluate survival in relation to prognostic factors at time of diag...

  18. Patient Outcomes in the Operative and Nonoperative Management of High-Grade Spondylolisthesis in Children

    DEFF Research Database (Denmark)

    Lundine, K. M.; Lewis, S. J.; Al-Aubaidi, Zaid

    2014-01-01

    Background:The optimal management of high-grade spondylolisthesis in the growing child is controversial. Some authors have advocated for surgery in all cases regardless of symptoms. Surgical intervention results in a >10% risk of complications with increased risk of neurological injury associated...

  19. L5 pedicle subtraction osteotomy for high-grade isthmic spondylolisthesis.

    Science.gov (United States)

    Radcliff, Kristen E; Jakoi, Andre M

    2015-04-01

    To the authors' knowledge, this is the first article to present a pedicle subtraction osteotomy in the lumbar spine to correct and stabilize a high-grade isthmic spondylolisthesis, which poses many challenges with regard to treatment options and outcomes. The optimal surgical treatment for high-grade spondylolisthesis is controversial, but the goals of treatment are to stabilize the affected spinal levels and to decompress the neural elements. A pedicle subtraction osteotomy is a reconstructive procedure that addresses fixed sagittal imbalance by increasing lumbar lordosis through posterior spinal column shortening. The authors report a 46-year-old patient with chronic, progressively worsening back and leg radiculopathy accompanied by sagittal plane malalignment and for which a pedicle subtraction osteotomy was performed. The procedure yielded stabilization of the patient's lumbar spondylolisthesis and sagittal plane alignment was restoration. At 3 months postoperatively, the patient's pain had fully resolved and her motor and neurologic examination exhibited no deficits. At 24 months postoperatively, she was still symptom-free and ambulating without assistance. This report is the first documented successful pedicle subtraction osteotomy in the treatment of high-grade spondylolisthesis. This report indicates that certain patient populations may be amenable to pedicle subtraction osteotomy as a treatment option for pathology involving high-grade isthmic spondylolisthesis. Copyright 2015, SLACK Incorporated.

  20. Examining the Accuracy of Self-Reported High School Grade Point Average

    Science.gov (United States)

    Shaw, Emily J.; Mattern, Krista D.

    2010-01-01

    [Slides] presented at AERA in Denver, CO in April 2010. This study examined the relationship between students' self-reported high school grade point average (HSGPA) from the SAT Questionnaire and their HSGPA provided by the colleges and universities they attend. The purpose of this research was to offer updated information on the relatedness of…

  1. High School Grade Inflation from 2004 to 2011. ACT Research Report Series, 2013 (3)

    Science.gov (United States)

    Zhang, Qian; Sanchez, Edgar I.

    2013-01-01

    This study explores inflation in high school grade point average (HSGPA), defined as trend over time in the conditional average of HSGPA, given ACT® Composite score. The time period considered is 2004 to 2011. Using hierarchical linear modeling, the study updates a previous analysis of Woodruff and Ziomek (2004). The study also investigates…

  2. Prevention of Ovarian High-Grade Serous Carcinoma by Elucidating Its Early Changes

    Science.gov (United States)

    2014-10-01

    iso - form expression in luteal phase fallopian tube epithelium and high-grade serous carcinoma. Endocr Relat Cancer (2011) 18:221–34. doi:10.1530/ERC-10...0 -1 -2 -3 8 norma ] samp1es - ,-, - • • 1 CM Control Lovastatin (50 mg/kg) C on tro l S ta tin (5 0m g/ kg ) S ta

  3. Achieving Hydrogen Storage Goals through High-Strength Fiber Glass - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hong [PPG Industries, Inc., Cheswick, PA (United States); Johnson, Kenneth I. [PPG Industries, Inc., Cheswick, PA (United States); Newhouse, Norman L. [PPG Industries, Inc., Cheswick, PA (United States)

    2017-06-05

    Led by PPG and partnered with Hexagon Lincoln and Pacific Northwest National Laboratory (PNNL), the team recently carried out a project “Achieving Hydrogen Storage Goals through High-Strength Fiber Glass”. The project was funded by DOE’s Fuel Cell Technologies office within the Office of Energy Efficiency and Renewable Energy, starting on September 1, 2014 as a two-year project to assess technical and commercial feasibilities of manufacturing low-cost, high-strength glass fibers to replace T700 carbon fibers with a goal of reducing the composite total cost by 50% of the existing, commercial 700 bar hydrogen storage tanks used in personal vehicles.

  4. Experimental Investigation of the Fracture Behaviour of Reinforced Ultra High Strength Concrete

    DEFF Research Database (Denmark)

    Ulfkjær, J. P.; Henriksen, M. S.; Aarup, B.

    In the last fifteen years new types of cement based materials have been developed in Denmark at the Aalborg Portland Cement Factory. These types of new materials are characterized by very high strength even when mixed at room temperature and using conventional mixing techniques. In this paper...... the structural behaviour of a very high strength cement based material with and without steel fibres is investigated. A simple structural geometry has been tested, namely a beam subjected to three point bending. The results shows that the increase of ductility of the material also gives a more ductile behaviour...

  5. Strength and Biot's coefficient for high-porosity oil- or water-saturated chalk

    DEFF Research Database (Denmark)

    Andreassen, Katrine Alling

    . The Biot coefficient states the degree of cementation or how the pore pressure contributes to the strain resulting from an external load for a porous material. It is here calculated from dynamic measurements and correlated with the strength of outcrop chalk characterized by the onset of pore collapse...... during hydrostatic loading. The hypothesis is that the Biot coefficient and the theory of poroelasticity may cover the fluid effect by including the increased fluid bulk modulus from oil to water. A high number of test results for both oil- and water-saturated high-porosity outcrop chalk show correlation...... between the Biot coefficient and the strength....

  6. The effect of surface layer properties on bendability of ultra-high strength steel

    Science.gov (United States)

    Arola, Anna-Maija; Kaijalainen, Antti; Kesti, Vili

    2016-10-01

    Bendability is an important property for ultra-high strength steel because air-bending is the most common forming process for the material. In this paper the bendability of two ultra-high strength steels with similar mechanical properties but different bendability was investigated using tensile testing with optical strain measurements. The tensile tests were conducted also for specimens cut from the surface layer and the middle layer of the sheet. It was discovered that the mechanical properties of the surface of the sheet affect the bendability in great manner.

  7. Transforaminal percutaneous endoscopic lumbar discectomy for very high-grade migrated disc herniation.

    Science.gov (United States)

    Ahn, Yong; Jang, Il-Tae; Kim, Woo-Kyung

    2016-08-01

    Transforaminal percutaneous endoscopic lumbar discectomy (PELD) for high-grade migrated disc herniation has been regarded as a challenging task, but because of the remarkable improvement in navigable instruments and advanced epiduroscopic technique, it can be used for the treatment of high- or very high-grade migrated disc herniation. The purpose of this study was to describe in detail the standardized technique of transforaminal PELD for very high-grade migrated disc herniation and demonstrate the clinical results. Very high-grade lumbar migrated disc herniation was defined as a disc migration beyond the inferior margin of the pedicle. Thirteen consecutive patients with very high-grade lumbar migrated disc herniation were treated with transforaminal PELD, which has three stages: (1) direction-oriented transforaminal approach, (2) release of periannular anchorage, and (3) epiduroscopic fragmentectomy with navigable instruments. The surgical outcomes were assessed using the visual analogue pain score (VAS), Oswestry disability index (ODI), and modified Macnab criteria. The operated levels were L3-4 in 2 (15.4%) patients, L4-5 in 10 (76.9%), and L5-S1 in 1 (7.7%). The directions of migration were cranial in 8 patients and caudal in 5. The mean VAS for leg pain improved from 7.86±1.28 preoperatively to 2.54±1.51 at 6 weeks postoperatively and 1.85±1.07 at 1year postoperatively (Pdisc herniation, and a standardized technique may provide a reliable and reproducible result. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Increased variability of watershed areas in patients with high-grade carotid stenosis

    DEFF Research Database (Denmark)

    Kaczmarz, Stephan; Griese, Vanessa; Preibisch, Christine

    2018-01-01

    of individual WSAs. Methods: We defined individual watershed masks based on relative TTP increases in 30 healthy elderly persons and 28 patients with unilateral, high-grade carotid stenosis, being at risk for watershed-related hemodynamic impairment. Determined WSA location was confirmed by an arterial transit...... variability of WSAs than healthy controls. Perfusion on the side of the stenosis was delayed within individual watershed masks as compared to a watershed template derived from controls, being independent from the grade of the stenosis and collateralization status of the circle of Willis. Conclusion: Results...

  9. Contemporary management of high-grade renal trauma: Results from the American Association for the Surgery of Trauma Genitourinary Trauma study.

    Science.gov (United States)

    Keihani, Sorena; Xu, Yizhe; Presson, Angela P; Hotaling, James M; Nirula, Raminder; Piotrowski, Joshua; Dodgion, Christopher M; Black, Cullen M; Mukherjee, Kaushik; Morris, Bradley J; Majercik, Sarah; Smith, Brian P; Schwartz, Ian; Elliott, Sean P; DeSoucy, Erik S; Zakaluzny, Scott; Thomsen, Peter B; Erickson, Bradley A; Baradaran, Nima; Breyer, Benjamin N; Miller, Brandi; Santucci, Richard A; Carrick, Matthew M; Hewitt, Timothy; Burks, Frank N; Kocik, Jurek F; Askari, Reza; Myers, Jeremy B

    2018-03-01

    The rarity of renal trauma limits its study and the strength of evidence-based guidelines. Although management of renal injuries has shifted toward a nonoperative approach, nephrectomy remains the most common intervention for high-grade renal trauma (HGRT). We aimed to describe the contemporary management of HGRT in the United States and also evaluate clinical factors associated with nephrectomy after HGRT. From 2014 to 2017, data on HGRT (American Association for the Surgery of Trauma grades III-V) were collected from 14 participating Level-1 trauma centers. Data were gathered on demographics, injury characteristics, management, and short-term outcomes. Management was classified into three groups-expectant, conservative/minimally invasive, and open operative. Descriptive statistics were used to report management of renal trauma. Univariate and multivariate logistic mixed effect models with clustering by facility were used to look at associations between proposed risk factors and nephrectomy. A total of 431 adult HGRT were recorded; 79% were male, and mechanism of injury was blunt in 71%. Injuries were graded as III, IV, and V in 236 (55%), 142 (33%), and 53 (12%), respectively. Laparotomy was performed in 169 (39%) patients. Overall, 300 (70%) patients were managed expectantly and 47 (11%) underwent conservative/minimally invasive management. Eighty-four (19%) underwent renal-related open operative management with 55 (67%) of them undergoing nephrectomy. Nephrectomy rates were 15% and 62% for grades IV and V, respectively. Penetrating injuries had significantly higher American Association for the Surgery of Trauma grades and higher rates of nephrectomy. In multivariable analysis, only renal injury grade and penetrating mechanism of injury were significantly associated with undergoing nephrectomy. Expectant and conservative management is currently utilized in 80% of HGRT; however, the rate of nephrectomy remains high. Clinical factors, such as surrogates of

  10. 5-Aminolevulinic Acid Fluorescence in High Grade Glioma Surgery: Surgical Outcome, Intraoperative Findings, and Fluorescence Patterns

    Directory of Open Access Journals (Sweden)

    Alessandro Della Puppa

    2014-01-01

    Full Text Available Background. 5-Aminolevulinic acid (5-ALA fluorescence is a validated technique for resection of high grade gliomas (HGG; the aim of this study was to evaluate the surgical outcome and the intraoperative findings in a consecutive series of patients. Methods. Clinical and surgical data from patients affected by HGG who underwent surgery guided by 5-ALA fluorescence at our Department between June 2011 and February 2014 were retrospectively evaluated. Surgical outcome was evaluated by assessing the resection rate as gross total resection (GTR>98% and GTR>90%. We finally stratified data for recurrent surgery, tumor location, tumor size, and tumor grade (IV versus III grade sec. WHO. Results. 94 patients were finally enrolled. Overall GTR>98% and GTR>90% was achieved in 93% and 100% of patients. Extent of resection (GTR>98% was dependent on tumor location, tumor grade (P<0.05, and tumor size (P<0.05. In 43% of patients the boundaries of fluorescent tissue exceeded those of tumoral tissue detected by neuronavigation, more frequently in larger (57% (P<0.01 and recurrent (60% tumors. Conclusions. 5-ALA fluorescence in HGG surgery enables a GTR in 100% of cases even if selection of patients remains a main bias. Recurrent surgery, and location, size, and tumor grade can predict both the surgical outcome and the intraoperative findings.

  11. Adenoid cystic carcinoma of the breast, high grade with basal phenotype, literature review

    Directory of Open Access Journals (Sweden)

    Enaam Junainah

    Full Text Available Adenoid cystic carcinoma (ACC is a rare type of breast carcinoma resembling adenoid cystic carcinoma of other sites. this type of tumors usually characterized by the exhibiting dual cell population of luminal and basaloid with specific growth pattern Most of these sub types are triple-negative with basal-like breast features (tumors that are devoid of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression, and express basal cell markers, they are usually low-grade but can be high grade, clinical behavior is indolent despite the nuclear grade, lymph node involvement or distant metastases which is rarely occur. Treatment is either simple mastectomy or lumpectomy. Chemotherapy, radiation and hormonal treatment have limited used in those cases. Keywords: Adenoid cystic carcinoma, Breast, Triple-negative and basal-like phenotype

  12. Comparison of Post Weld Treatment of High Strength Steel Welded Joints in Medium Cycle Fatigue

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Melters; Mouritsen, Ole Ø.; Hansen, Michael Rygaard

    2010-01-01

    This paper presents a comparison of three post-weld treatments for fatigue life improvement of welded joints. The objective is to determine the most suitable post-weld treatment for implementation in mass production of certain crane components manufactured from very high-strength steel...... the stress range can exceed the yield-strength of ordinary structural steel, especially when considering positive stress ratios (R > 0). Fatigue experiments and qualitative evaluation of the different post-weld treatments leads to the selection of TIG dressing. The process of implementing TIG dressing...... in mass production and some inherent initial problems are discussed. The treatment of a few critical welds leads to a significant increase in fatigue performance of the entire structure and the possibility for better utilization of very high-strength steel....

  13. High grade neuroendocrine lung tumors: pathological characteristics, surgical management and prognostic implications.

    Science.gov (United States)

    Grand, Bertrand; Cazes, Aurélie; Mordant, Pierre; Foucault, Christophe; Dujon, Antoine; Guillevin, Elizabeth Fabre; Barthes, Françoise Le Pimpec; Riquet, Marc

    2013-09-01

    Among non-small cell lung cancers (NSCLC), large cell carcinoma (LCC) is credited of significant adverse prognosis. Its neuroendocrine subtype has even a poorer diagnosis, with long-term survival similar to small cell lung cancer (SCLC). Our purpose was to review the surgical characteristics of those tumors. The clinical records of patients who underwent surgery for lung cancer in two French centers from 1980 to 2009 were retrospectively reviewed. We more particularly focused on patients with LCC or with high grade neuroendocrine lung tumors. High grade neuroendocrine tumors were classified as pure large cell neuroendocrine carcinoma (pure LCNEC), NSCLC combined with LCNEC (combined LCNEC), and SCLC combined with LCNEC (combined SCLC). There were 470 LCC and 155 high grade neuroendocrine lung tumors, with no difference concerning gender, mean age, smoking habits. There were significantly more exploratory thoracotomies in LCC, and more frequent postoperative complications in high grade neuroendocrine lung tumors. Pathologic TNM and 5-year survival rates were similar, with 5-year ranging from 34.3% to 37.6% for high grade neuroendocrine lung tumors and LCC, respectively. Induction and adjuvant therapy were not associated with an improved prognosis. The subgroups of LCNEC (pure NE, combined NE) and combined SCLC behaved similarly, except visceral pleura invasion, which proved more frequent in combined NE and less frequent in combined SCLC. Survival analysis showed a trend toward a lower 5-year survival in case of combined SCLC. Therefore, LCC, LCNEC and combined SCLC share the same poor prognosis, but surgical resection is associated with long-term survival in about one third of patients. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Metastable high-entropy dual-phase alloys overcome the strength-ductility trade-off.

    Science.gov (United States)

    Li, Zhiming; Pradeep, Konda Gokuldoss; Deng, Yun; Raabe, Dierk; Tasan, Cemal Cem

    2016-06-09

    Metals have been mankind's most essential materials for thousands of years; however, their use is affected by ecological and economical concerns. Alloys with higher strength and ductility could alleviate some of these concerns by reducing weight and improving energy efficiency. However, most metallurgical mechanisms for increasing strength lead to ductility loss, an effect referred to as the strength-ductility trade-off. Here we present a metastability-engineering strategy in which we design nanostructured, bulk high-entropy alloys with multiple compositionally equivalent high-entropy phases. High-entropy alloys were originally proposed to benefit from phase stabilization through entropy maximization. Yet here, motivated by recent work that relaxes the strict restrictions on high-entropy alloy compositions by demonstrating the weakness of this connection, the concept is overturned. We decrease phase stability to achieve two key benefits: interface hardening due to a dual-phase microstructure (resulting from reduced thermal stability of the high-temperature phase); and transformation-induced hardening (resulting from the reduced mechanical stability of the room-temperature phase). This combines the best of two worlds: extensive hardening due to the decreased phase stability known from advanced steels and massive solid-solution strengthening of high-entropy alloys. In our transformation-induced plasticity-assisted, dual-phase high-entropy alloy (TRIP-DP-HEA), these two contributions lead respectively to enhanced trans-grain and inter-grain slip resistance, and hence, increased strength. Moreover, the increased strain hardening capacity that is enabled by dislocation hardening of the stable phase and transformation-induced hardening of the metastable phase produces increased ductility. This combined increase in strength and ductility distinguishes the TRIP-DP-HEA alloy from other recently developed structural materials. This metastability-engineering strategy should

  15. ERBB2 mutations associated with solid variant of high-grade invasive lobular breast carcinomas.

    Science.gov (United States)

    Deniziaut, Gabrielle; Tille, Jean Christophe; Bidard, François-Clément; Vacher, Sophie; Schnitzler, Anne; Chemlali, Walid; Trémoulet, Laurence; Fuhrmann, Laetitia; Cottu, Paul; Rouzier, Roman; Bièche, Ivan; Vincent-Salomon, Anne

    2016-11-08

    ERBB2 and ERBB3 somatic gain-of-function mutations, which may be targeted by anti-ERBB2 therapies, were reported by high-throughput sequencing studies in 1% and 2% of invasive breast cancers respectively. Our study aims to determine ERBB2 and ERBB3 mutations frequencies in grade 3 and/or ERBB2-positive invasive lobular breast carcinomas (ILC). All the 529 ILC surgically-excised registered at Institut Curie in the years 2005 to 2008 were reviewed. Thirty-nine grade 3 ERBB2-negative ILC and 16 ERBB2-positive ILC were retrieved and subjected to Sanger sequencing of the ERBB2 and ERBB3 activation mutation hotspots (ERBB2: exons 8, 17, 19, 20, 21; ERBB3: exons 3, 6, 7, 8). Among the 39 grade 3 ERBB2-negative ILC, six tumors were found to have at least one detectable ERBB2 activating mutation (incidence rate: 15%, 95%CI [4%-27%]). No ERBB2 mutation was found among the 16 ERBB2-positive ILC. No ERBB3 mutation was found in any of the 55 ILC. ERBB2 mutations were statistically associated with solid ILC features (p=0.01). Survival analyses showed no significant prognostic impact of ERBB2 mutations. Our study demonstrates that high grade ERBB2-negative ILC display a high frequency of ERBB2 mutations, and should be subjected to systematic genetic screening.

  16. Effects of Pelvic and Core Strength Training on High School Cross-Country Race Times.

    Science.gov (United States)

    Clark, Anne W; Goedeke, Maggie K; Cunningham, Saengchoy R; Rockwell, Derek E; Lehecka, Bryan J; Manske, Robert C; Smith, Barbara S

    2017-08-01

    Clark, AW, Goedeke, MK, Cunningham, SR, Rockwell, DE, Lehecka, BJ, Manske, RC, and Smith, BS. Effects of pelvic and core strength training on high school cross-country race times. J Strength Cond Res 31(8): 2289-2295, 2017-There is only limited research examining the effect of pelvic and core strength training on running performance. Pelvic and core muscle fatigue is believed to contribute to excess motion along frontal and transverse planes which decreases efficiency in normal sagittal plane running motions. The purpose of this study was to determine whether adding a 6-week pelvic and core strengthening program resulted in decreased race times in high school cross-country runners. Thirty-five high school cross-country runners (14-19 years old) from 2 high schools were randomly assigned to a strengthening group (experimental) or a nonstrengthening group (control). All participants completed 4 standardized isometric strength tests for hip abductors, adductors, extensors, and core musculature in a test-retest design. The experimental group performed a 6-week pelvic and core strengthening program along with their normal training. Participants in the control group performed their normal training without additional pelvic and core strengthening. Baseline, 3-week, and 6-week race times were collected using a repeated measures design. No significant interaction between experimental and control groups regarding decreasing race times and increasing pelvic and core musculature strength occurred over the 6-week study period. Both groups increased strength and decreased overall race times. Clinically significant findings reveal a 6-week pelvic and core stability strengthening program 3 times a week in addition to coach led team training may help decrease race times.

  17. Warm Spraying of High-Strength Ni-Al-Bronze: Cavitation Characteristics and Property Prediction

    Science.gov (United States)

    Krebs, Sebastian; Kuroda, Seiji; Katanoda, Hiroshi; Gaertner, Frank; Klassen, Thomas; Araki, Hiroshi; Frede, Simon

    2017-01-01

    Bronze materials such as Ni-Al-bronze show exceptional performances against cavitation erosion, due to their high fatigue strength and high strength. These materials are used for ship propellers, pump systems or for applications with alternating stresses. Usually, the respective parts are cast. With the aim to use resources more efficiently and to reduce costs, this study aimed to evaluate opportunities to apply bronze as a coating to critical areas of respective parts. The coatings should have least amounts of pores and non-bonded areas and any contaminations that might act as crack nuclei and contribute to material damages. Processes with low oxidation and high kinetic impacts fulfill these criteria. Especially warm spraying, a nitrogen-cooled HVOF process, with similar impact velocities as cold gas spraying but enhanced process temperature, allows for depositing high-strength Ni-Al-bronze. This study systematically simulates and evaluates the formation and performance of warm-sprayed Ni-Al-bronze coatings for different combustion pressures and nitrogen flow rates. Substrate preheating was used to improve coating adhesion for lower spray parameter sets. Furthermore, this study introduces an energy-based concept to compare spray parameter sets and to predict coating properties. Coatings with low porosities and high mechanical strengths are obtained, allowing for a cavitation resistance similar to bulk material.

  18. Creep Behavior of High-Strength Concrete Subjected to Elevated Temperatures.

    Science.gov (United States)

    Yoon, Minho; Kim, Gyuyong; Kim, Youngsun; Lee, Taegyu; Choe, Gyeongcheol; Hwang, Euichul; Nam, Jeongsoo

    2017-07-11

    Strain is generated in concrete subjected to elevated temperatures owing to the influence of factors such as thermal expansion and design load. Such strains resulting from elevated temperatures and load can significantly influence the stability of a structure during and after a fire. In addition, the lower the water-to-binder (W-B) ratio and the smaller the quantity of aggregates in high-strength concrete, the more likely it is for unstable strain to occur. Hence, in this study, the compressive strength, elastic modulus, and creep behavior were evaluated at target temperatures of 100, 200, 300, 500, and 800 °C for high-strength concretes with W-B ratios of 30%, 26%, and 23%. The loading conditions were set as non-loading and 0.33f cu . It was found that as the compressive strength of the concrete increased, the mechanical characteristics deteriorated and transient creep increased. Furthermore, when the point at which creep strain occurred at elevated temperatures after the occurrence of transient creep was considered, greater shrinkage strain occurred as the compressive strength of the concrete increased. At a heating temperature of 800 °C, the 80 and 100 MPa test specimens showed creep failure within a shrinkage strain range similar to the strain at the maximum load.

  19. Properties of Fresh and Hardened High Strength Steel Fibres Reinforced Self-Compacted Concrete

    Directory of Open Access Journals (Sweden)

    Saad Ali Al-Ta'an

    2016-10-01

    Full Text Available Fresh and hardened properties of high strength steel fibrous self-compacted concrete were studied in this investigation. One reference high strength self-compacted concrete mix is used, with five percent (by weight of cement silica fume and eight percent of the cement replaced by limestone powder. Three steel fibres percentages by volume of concrete are used (0.4, 0.8, and 1.2. The used steel fibres were a shelled Harex type with irregular cross-section, equivalent diameter of 0.9278 mm, and 32 mm long. Super plasticizer was used to improve the workability and flow ability of the mixes. The test results showed that the presence of steel fibres decrease the flow ability, and increase the time of spreading, segregation, and passing ability of the fresh concrete. For the fibres percentages used, the fresh properties were within the recommended specifications for the self-compacted concrete. The test results showed an early strength development rate more than that for plain normal concrete due to the presence of the fine materials. As for normal concrete, the test results showed also that the increase in the splitting strength is more than the increase in the compressive strength due to the presence of the steel fibres. The brittle mode of failure of the plain unreinforced specimens changed to a ductile one due to the presence of the steel fibres.

  20. Creep Behavior of High-Strength Concrete Subjected to Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Minho Yoon

    2017-07-01

    Full Text Available Strain is generated in concrete subjected to elevated temperatures owing to the influence of factors such as thermal expansion and design load. Such strains resulting from elevated temperatures and load can significantly influence the stability of a structure during and after a fire. In addition, the lower the water-to-binder (W–B ratio and the smaller the quantity of aggregates in high-strength concrete, the more likely it is for unstable strain to occur. Hence, in this study, the compressive strength, elastic modulus, and creep behavior were evaluated at target temperatures of 100, 200, 300, 500, and 800 °C for high-strength concretes with W–B ratios of 30%, 26%, and 23%. The loading conditions were set as non-loading and 0.33fcu. It was found that as the compressive strength of the concrete increased, the mechanical characteristics deteriorated and transient creep increased. Furthermore, when the point at which creep strain occurred at elevated temperatures after the occurrence of transient creep was considered, greater shrinkage strain occurred as the compressive strength of the concrete increased. At a heating temperature of 800 °C, the 80 and 100 MPa test specimens showed creep failure within a shrinkage strain range similar to the strain at the maximum load.

  1. Development of high strength steel sheets for crashworthiness; Shototsu anzen`yo kokyodo usu koban no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, K.; Yamamoto, M.; Mizui, N.; Hirose, Y.; Kojima, K. [Sumitomo Metal Industries, Ltd. Osaka (Japan)

    1997-10-01

    For frontal or rear members of automotive body, the most suitable high strength steel was investigated. Dynamic tensile test at strain-rate of 2000/s and crash test of hat-shape column at 4m/s were conducted for steel sheets with tensile strength ranging from 290 to 980 MPa. Dynamic tensile strength increases with increasing static one but the ratio of dynamic tensile strength to static one decreases. Tensile strength remarkably affects crash energy absorption of column and TRIP steel is superior to other steels with same tensile strength. 7 refs., 16 figs., 1 tab.

  2. Relationship between grip, pinch strengths and anthropometric variables, types of pitch throwing among Japanese high school baseball pitchers.

    Science.gov (United States)

    Tajika, Tsuyoshi; Kobayashi, Tsutomu; Yamamoto, Atsushi; Shitara, Hitoshi; Ichinose, Tsuyoshi; Shimoyama, Daisuke; Okura, Chisa; Kanazawa, Saeko; Nagai, Ayako; Takagishi, Kenji

    2015-03-01

    Grip and pinch strength are crucially important attributes and standard parameters related to the functional integrity of the hand. It seems significant to investigate normative data for grip and pinch strength of baseball players to evaluate their performance and condition. Nevertheless, few reports have explained the association between grip and pinch strength and anthropometric variables and types of pitch throwing for baseball pitchers. The aim of this study was to measure and evaluate clinical normative data for grip and tip, key, palmar pinch strength and to assess the relationship between these data and anthropometric variables and types of pitch throwing among Japanese high-school baseball pitchers. One hundred-thirty three healthy high school baseball pitchers were examined and had completed a self-administered questionnaire including items related to age, hand dominance, throwing ratio of type of pitch. A digital dynamometer was used to measure grip strength and a pinch gauge to measure tip, key and palmer pinch in both dominant and nondominant side. Body composition was measured by the multi frequency segmental body composition analyzer. Grip strength and tip and palmer pinch strength in dominant side were statistically greater than them in nondominant side (P strength and height (r = 0.33, P strength were predictors of grip strength in dominant side. No statistical significant correlations were found between the throwing ratio of types of pitches thrown and grip strength and tip, key, palmar pinch strength. Our result provides normative values and evidences for grip and pinch strengths in high school baseball pitchers.

  3. Textural analysis of pre-therapeutic [18F]-FET-PET and its correlation with tumor grade and patient survival in high-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Pyka, Thomas; Hiob, Daniela; Wester, Hans-Juergen [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [Klinikum Rechts der Isar der TU Muenchen, Neurosurgic Department, Munich (Germany); Schlegel, Juergen [Klinikum Rechts der Isar der TU Muenchen, Institute of Pathology and Neuropathology, Munich (Germany); Bette, Stefanie [Klinikum Rechts der Isar der TU Muenchen, Neuroradiologic department, Munich (Germany); Foerster, Stefan [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Klinikum Rechts der Isar der TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

    2016-01-15

    Amino acid positron emission tomography (PET) with [18F]-fluoroethyl-L-tyrosine (FET) is well established in the diagnostic work-up of malignant brain tumors. Analysis of FET-PET data using tumor-to-background ratios (TBR) has been shown to be highly valuable for the detection of viable hypermetabolic brain tumor tissue; however, it has not proven equally useful for tumor grading. Recently, textural features in 18-fluorodeoxyglucose-PET have been proposed as a method to quantify the heterogeneity of glucose metabolism in a variety of tumor entities. Herein we evaluate whether textural FET-PET features are of utility for grading and prognostication in patients with high-grade gliomas. One hundred thirteen patients (70 men, 43 women) with histologically proven high-grade gliomas were included in this retrospective study. All patients received static FET-PET scans prior to first-line therapy. TBR (max and mean), volumetric parameters and textural parameters based on gray-level neighborhood difference matrices were derived from static FET-PET images. Receiver operating characteristic (ROC) and discriminant function analyses were used to assess the value for tumor grading. Kaplan-Meier curves and univariate and multivariate Cox regression were employed for analysis of progression-free and overall survival. All FET-PET textural parameters showed the ability to differentiate between World Health Organization (WHO) grade III and IV tumors (p < 0.001; AUC 0.775). Further improvement in discriminatory power was possible through a combination of texture and metabolic tumor volume, classifying 85 % of tumors correctly (AUC 0.830). TBR and volumetric parameters alone were correlated with tumor grade, but showed lower AUC values (0.644 and 0.710, respectively). Furthermore, a correlation of FET-PET texture but not TBR was shown with patient PFS and OS, proving significant in multivariate analysis as well. Volumetric parameters were predictive for OS, but this correlation did not

  4. High-grade renal injuries are often isolated in sports-related trauma.

    Science.gov (United States)

    Patel, Darshan P; Redshaw, Jeffrey D; Breyer, Benjamin N; Smith, Thomas G; Erickson, Bradley A; Majercik, Sarah D; Gaither, Thomas W; Craig, James R; Gardner, Scott; Presson, Angela P; Zhang, Chong; Hotaling, James M; Brant, William O; Myers, Jeremy B

    2015-07-01

    Most high-grade renal injuries (American Association for Surgery of Trauma (AAST) grades III-V) result from motor vehicle collisions associated with numerous concomitant injuries. Sports-related blunt renal injury tends to have a different mechanism, a solitary blow to the flank. We hypothesized that high-grade renal injury is often isolated in sports-related renal trauma. We identified patients with AAST grades III-V blunt renal injuries from four level 1 trauma centres across the United States between 1/2005 and 1/2014. Patients were divided into "Sport" or "Non-sport" related groups. Outcomes included rates of hypotension (systolic blood pressure 110bpm), concomitant abdominal injury, and procedural/surgical intervention between sports and non-sports related injury. 320 patients met study criteria. 18% (59) were sports-related injuries with the most common mechanisms being skiing, snowboarding and contact sports (25%, 25%, and 24%, respectively). Median age was 24 years for sports and 30 years for non-sports related renal injuries (p=0.049). Males were more commonly involved in sports related injuries (85% vs. 72%, p=0.011). Median injury severity score was lower for sports related injuries (10 vs. 27, pinjury scale scores. Sports related trauma was more likely to be isolated without other significant injury (69% vs. 39% (psports and non-sports renal injuries (p=0.30). Sports injuries had lower transfusion (7% vs. 47%, psports vs. 18% non-sports, p=0.95). High-grade sports-related blunt renal trauma is more likely to occur in isolation without other abdominal or thoracic injuries and clinicians must have a high suspicion of renal injury with significant blows to the flank during sports activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. A Levering Technique Using Small Parallel Rods for Open Reduction of High-Grade Thoracolumbar Dislocation

    OpenAIRE

    Hadgaonkar, Shailesh; Shah, Kunal; Khurjekar, Ketan; Krishnan, Vibhu; Shyam, Ashok; Sancheti, Parag

    2017-01-01

    Study Design: Technical report. Objective: Dorsolumbar vertebral dislocations, with or without associated fractures, occur secondary to very high velocity trauma. The reduction procedures and techniques, which may be adopted in these situations, have been multifariously discussed in the literature. Our objective was to assess the outcome of a novel reduction maneuver, using parallel rods which we have employed in reduction of high-grade thoracolumbar fractures to achieve precise sagittal bala...

  6. Prediction and stratification of upper limb function and self-care in acute cervical spinal cord injury with the graded redefined assessment of strength, sensibility, and prehension (GRASSP).

    Science.gov (United States)

    Velstra, Inge-Marie; Bolliger, Marc; Tanadini, Lorenzo Giuseppe; Baumberger, Michael; Abel, Rainer; Rietman, Johan S; Curt, Armin

    2014-09-01

    There is inherent heterogeneity within individuals suffering from cervical spinal cord injury (SCI), and early prediction of upper limb function and self-care is challenging. As a result, considerable uncertainty exists regarding the prediction of functional outcome following cervical SCI within 1 year of injury. To evaluate the value of Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) in predicting upper limb function and self-care outcomes in individuals with cervical SCI. A prospective longitudinal multicenter study was performed. Data from the GRASSP, the Spinal Cord Independence Measure (SCIM III), and the American Spinal Injury Association (ASIA) Impairment Scale were recorded at 1, 6, and 12 months after cervical SCI. For prediction of functional outcome at 6 and 12 months, a logistic regression model, receiver operating characteristics (ROC), and unbiased recursive partitioning conditional inference tree (URP-CTREE) were used with 8 different predictor variables. Logistic regression analysis, ROC analysis, and URP-CTREE all revealed that the strength subtest within GRASSP is the strongest predictor for upper limb function and self-care outcomes. URP-CTREE provides useful information on the distribution of different outcomes in acute cervical SCI and can be used to predict cohorts with homogeneous outcomes. The GRASSP at 1 month can accurately predict upper limb function and self-care outcomes even in a heterogeneous group of individuals across a wide spectrum of neurological recovery. The application of URP-CTREE can reveal the distribution of outcome categories and, based on this, inform trial protocols with respect to outcomes analysis and patient stratification. © The Author(s) 2014.

  7. Responsiveness, Sensitivity, and Minimally Detectable Difference of the Graded and Redefined Assessment of Strength, Sensibility, and Prehension, Version 1.0.

    Science.gov (United States)

    Kalsi-Ryan, Sukhvinder; Beaton, Dorcas; Ahn, Henry; Askes, Heather; Drew, Brian; Curt, Armin; Popovic, Milos R; Wang, Justin; Verrier, Mary C; Fehlings, Michael G

    2016-02-01

    As spinal cord injury (SCI) trials begin to involve subjects with acute cervical SCI, establishing the property of an upper limb outcome measure to detect change over time is critical for its usefulness in clinical trials. The objectives of this study were to define responsiveness, sensitivity, and minimally detectable difference (MDD) of the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP). An observational, longitudinal study was conducted. International Standards of Neurological Classification of SCI (ISNCSCI), GRASSP, Capabilities of Upper Extremity Questionnaire (CUE-Q), and Spinal Cord Independence Measure (SCIM) were administered 0-10 days, 1, 3, 6, and 12 months post-injury. Standardized Response Means (SRM) for GRASSP and ISNCSCI measures were calculated. Longitudinal construct validity was calculated using Pearson correlation coefficients. Smallest real difference for all subtests was calculated to define the MDD values for all GRASSP subtests. Longitudinal construct validity demonstrated GRASSP and all external measures to be responsive to neurological change for 1 year post-injury. SRM values for the GRASSP subtests ranged from 0.25 to 0.85 units greater than that for ISNCSCI strength and sensation, SCIM-SS, and CUE-Q. MDD values for GRASSP subtests ranged from 2-5 points. GRASSP demonstrates good responsiveness and excellent sensitivity that is superior to ISNCSCI and SCIM III. MDD values are useful in the evaluation of interventions in both clinical and research settings. The responsiveness and sensitivity of GRASSP make it a valuable condition-specific measure in tetraplegia, where changes in upper limb neurological and functional outcomes are essential for evaluating the efficacy of interventions.

  8. The electric strength of high-voltage transformers insulation at effect of partial dischargers

    International Nuclear Information System (INIS)

    Khoshravan, E.; Zeraatparvar, A.; Gashimov, A.M.; Mehdizadeh, R.N.

    2001-01-01

    Full text : In paper the change of electric strength of high-voltage transformers insulation at the effect of partial discharges with space charge accumulation was investigated. It is revealed that the effect of partial discharges of insulation materials results the reduction of their pulsing electric strength which can restore the own initial value at releasing of saved charge the volume of a material under condition of absence the ineversible structural changes in it. Researches of high-voltage transformers insulation's non-failure operation conditions show, that at increasing of insulation work time in a strong electrical field the reduction of average breakdown voltages with simultaneous increasing of spread in discharge voltage values takes place. It authentically testifies to reduction of short-time discharge voltage of insulation materials during their electrical aging. As the basic reason of insulation electrical aging the partial discharges occurring in gas cavities inside insulation were considered. It is known that the space charges will be formed in insulation elements of high-voltage devices which effects in dielectrical property of these elements including the electric strength and the space charge formation can occur also at partial discharges in an alternating voltage while the service of high-voltage transformers. In the given work the experiments in revealing separate influence partial discharges in pulsing electric strength of insulation materials at presence and at absence inside them the space charge were spent

  9. Weldability prediction of high strength steel S960QL after weld thermal cycle simulation

    Directory of Open Access Journals (Sweden)

    M. Dunđer

    2014-10-01

    Full Text Available This paper presents weld thermal cycle simulation of high strength steel S960QL, and describes influence of cooling time t8/5 on hardness and impact toughness of weld thermal cycle simulated specimens. Furthermore, it presents analysis of characteristic fractions done by electron scanning microscope which can contribute to determination of welding parameters for S960QL steel.

  10. USE OF HIGH-STRENGTH BAINITIC CAST IRON FOR PRODUCING GEAR WHEELS

    Directory of Open Access Journals (Sweden)

    A. I. Pokrovskiy

    2015-01-01

    Full Text Available The advantages and drawbacks of high-strength cast irons with bainitic structure are reviewed basing on the authors’ own experience in the production of critical partsfrom this material and on the analysis of world trends. A possibility of the replacement of alloy steels by bainitic cast iron in manufacturing critical machine parts is discussed.

  11. Analysis of the weld strength of the High Density Polyethylene (HDPE)

    African Journals Online (AJOL)

    An analysis was carried out to determine the strength of welded joints in High Density Polyethylene (HDPE) dam liners. Samples were collected of welded joints and subjected to tensile tests and creep test. It was observed that the welded joints from field welded samples were much weaker and had a very low straining ...

  12. Numerical Analysis on the High-Strength Concrete Beams Ultimate Behaviour

    Science.gov (United States)

    Smarzewski, Piotr; Stolarski, Adam

    2017-10-01

    Development of technologies of high-strength concrete (HSC) beams production, with the aim of creating a secure and durable material, is closely linked with the numerical models of real objects. The three-dimensional nonlinear finite element models of reinforced high-strength concrete beams with a complex geometry has been investigated in this study. The numerical analysis is performed using the ANSYS finite element package. The arc-length (A-L) parameters and the adaptive descent (AD) parameters are used with Newton-Raphson method to trace the complete load-deflection curves. Experimental and finite element modelling results are compared graphically and numerically. Comparison of these results indicates the correctness of failure criteria assumed for the high-strength concrete and the steel reinforcement. The results of numerical simulation are sensitive to the modulus of elasticity and the shear transfer coefficient for an open crack assigned to high-strength concrete. The full nonlinear load-deflection curves at mid-span of the beams, the development of strain in compressive concrete and the development of strain in tensile bar are in good agreement with the experimental results. Numerical results for smeared crack patterns are qualitatively agreeable as to the location, direction, and distribution with the test data. The model was capable of predicting the introduction and propagation of flexural and diagonal cracks. It was concluded that the finite element model captured successfully the inelastic flexural behaviour of the beams to failure.

  13. Steel-to-timber joints of beech-lvl with very high strength steel dowels

    NARCIS (Netherlands)

    Misconel, A.; Ballerini, M.; van de Kuilen, J.W.G.; Eberhardsteiner, J.; Winter, W.; Fadai, A.; Pöll, M.

    2016-01-01

    Double-shear steel-to-timber joints of beech laminated veneer lumber (LVL) with slotted-in steel plates using very high strength steel (VHSS) dowels have been investigated. Tensile tests on full-scale joints with one, two, three and six dowels have been carried out,

  14. Kic size effect study on two high-strength steels using notched bend specimens

    Science.gov (United States)

    Stonesifer, F. R.

    1974-01-01

    Five methods are used to calculate plane strain fracture toughness (K sub Q) values for bend-specimens of various sizes from two high-strength steels. None of the methods appeared to satisfactorily predict valid stress intensity factor (K sub IC) values from specimens of sizes well below that required by E399 standard tests.

  15. The Effect of Cathodic Protection on Stress Corrosion Cracking of High-Strength Pipeline Steels, #350

    Science.gov (United States)

    2009-12-02

    The objective of this study was to establish the effect of cathodic protection (CP) to produce hydrogen that can cause cracking and in-service failures of high-strength pipeline steels, from X-70 to X-120, and to establish the effectiveness of cathod...

  16. Fatigue properties of high-strength materials used in cold-forging tools

    DEFF Research Database (Denmark)

    Brøndsted, P.; Skov-Hansen, P.

    1998-01-01

    In the present work classical analytical models are used to describe the static stress–strain curves, low-cycle fatigue properties and fatigue crack growth behaviour of high-strength materials for use in tools for metal-forming processes such as cold forging and extrusion. The paper describes...

  17. In-situ high field strength testing using a transportable reverberation chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2008-01-01

    A reverberation chamber can create very high field strength with moderate input power. Existing chambers are making use of a paddle wheel to change the resonant modes in the chamber. In the case of a stepper motor, the field is stable for some time, and this type of reverberation chamber is called

  18. Fretting fatigue behavior of high-strength steel monostrands under bending load

    DEFF Research Database (Denmark)

    Winkler, Jan; Georgakis, Christos T.; Fischer, Gregor

    2015-01-01

    In this paper, the fretting fatigue behavior of pretensioned high-strength steel monostrands is investigated. To measure the local deformations on the strands, a novel method based on the digital image correlation (DIC) technique was used to quantify the relative movement between individual wires...

  19. Experimental evaluation of the fretting fatigue behavior of high-strength steel monostrands

    DEFF Research Database (Denmark)

    Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.

    2013-01-01

    In this paper, the fretting fatigue behavior of pretensioned high-strength steel monostrands is investigated. A method based on the digital image correlation (DIC) technique was used to quantify the relative movement between individual wires along the length of the monostrand. The experimental da...

  20. Body mass index, serum total cholesterol, and risk of gastric high-grade dysplasia

    Science.gov (United States)

    Huang, Ya-Kai; Kang, Wei-Ming; Ma, Zhi-Qiang; Liu, Yu-Qin; Zhou, Li; Yu, Jian-Chun

    2016-01-01

    Abstract Obesity is related to an increased risk of gastric cardia cancer. However, the influences of excess body weight and serum total cholesterol on the risk of gastric high-grade dysplasia have not been fully characterized. A case–control study was conducted to explore the relationships between body mass index (BMI), serum total cholesterol level, and the risk of gastric high-grade dysplasia in Chinese adults. A total of 893 consecutive patients with gastric high-grade dysplasia (537 men and 356 women) and 902 controls (543 men and 359 women) were enrolled from January 2000 to October 2015. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated, and a multivariate analysis was conducted. After adjusting for age, alcohol consumption, smoking status, family history of gastric cancer or esophageal cancer, and serum total cholesterol level, a BMI ranging from 27.5 to 29.9 was significantly related to an increased risk of gastric high-grade dysplasia in both men (adjusted OR = 1.87, 95% CI = 1.24–2.81) and women (adjusted OR = 2.72, 95% CI = 1.44–5.16). The 2 highest BMI categories (27.5–29.9 and ≥30.0) were identified as risk factors for gastric cardia high-grade dysplasia in both men (BMI = 27.5–29.9: adjusted OR = 1.78, 95% CI = 1.02–3.10; BMI ≥ 30.0: adjusted OR = 2.54, 95% CI = 1.27–5.08) and women (BMI = 27.5–29.9: adjusted OR = 2.88, 95% CI = 1.27–6.55; BMI ≥ 30.0: adjusted OR = 2.77, 95% CI = 1.36–5.64), whereas only a BMI ranging from 27.5 to 29.9 was a risk factor for gastric noncardia high-grade dysplasia in both men (adjusted OR = 1.98, 95% CI = 1.25–3.14) and women (adjusted OR = 2.88, 95% CI = 1.43–5.81). In addition, higher serum total cholesterol was associated with an increased risk of gastric noncardia high-grade dysplasia (adjusted OR = 1.83, 95% CI = 1.25–2.69) in women. Increased BMI was associated with an increased risk

  1. Development of high-mechanical strength electrical insulations for tokamak toroidal field coils

    International Nuclear Information System (INIS)

    Burke, C.

    1977-01-01

    The electrical insulation for the TF (Toroidal Field) coils is subjected to a high interlaminar shear, tensile and compressive stresses. Two candidate epoxy/glass fiber systems using prepreg and vacuum impregnation techniques were evaluated. Specimens were prepared and processed under controlled conditions to simulate specification manufacturing procedures. The strengths of the insulation were measured in interlaminar shear, tension, compression, and combined shear and compression statically. Shear modulus determinations were also made. Various techniques of surface treatments to increase bond strengths with three resin primers were tested

  2. Neptunium(V) adsorption to bacteria at low and high ionic strength

    Energy Technology Data Exchange (ETDEWEB)

    Ams, David A [Los Alamos National Laboratory; Swanson, Juliet S [Los Alamos National Laboratory; Reed, Donald T [Los Alamos National Laboratory; Fein, Jeremy B [UNIV OF NOTRE DAME

    2010-12-08

    Np(V) is expected to be the predominant oxidation state of neptunium in aerobic natural waters. Np(V), as the NpO{sub 2}{sup +} aquo and associated complexed species, is readily soluble, weakly interacting with geologic media, and has a high redox stability under a relatively wide range of subsurface conditions. These chemical properties, along with a long half-life make it a primary element of concern regarding long-term nuclear waste storage and subsurface contaminant. The fate and transport of neptunium in the environment may be influenced by adsorption onto bacterial surfaces. The adsorption of neptunium to bacterial surfaces ties the mobility of the contaminant to the mobility of the bacterium. In this study, the adsorption of the neptunyl (NpO{sub 2}{sup +}) ion was evaluated at low ionic strength on a common soil bacterium and at high ionic strength on a halophilic bacterium isolated from a briny groundwater near the Waste Isolation Pilot Plant (WIPP) in southeast New Mexico. Adsorption experiments were performed in batch reactors as a function of pH, ionic strength, and bacterialNp mass ratio. Np(V) adsorption was modeled using a surface complexation approach with the mathematical program FITEQL to determine functional group specific binding constants. The data from acid and base titrations of the bacteria were also modeled to estimate the concentrations and deprotonation constants of discrete bacterial surface functional groups. Bacterial functional group characteristics and Np(V) adsorption behavior between the soil bacterium and the halophilic bacterium were compared. These results highlight the key similarities and differences in actinide adsorption behavior in environments of significantly different ionic strength. Similarities in adsorption behavior may be linked to similarities in the characteristics of the moieties between all bacterial cell walls. Differences in adsorption behavior may reflect differences in ionic strength effects, rather than

  3. Effect of tempering time on the ballistic performance of a high strength armour steel

    OpenAIRE

    Pradipta Kumar Jena; Ponguru Senthil P.; Siva Kumar K.

    2016-01-01

    The investigation describes and analyses the effect of tempering time on the mechanical and ballistic performance of a high strength armour steel. The steel is subjected to tempering at 300 °C for 2, 24 and 48 h. A marginal variation in strength and hardness is observed with increase in tempering time, whereas ductility and Charpy impact values are found to be decreasing. Ballistic performance of the samples are evaluated by impacting 7.62 mm and 12.7 mm armour piercing projectiles at 0° angl...

  4. Aerospace Patented High-Strength Aluminum Alloy Used in Commercial Industries

    Science.gov (United States)

    2004-01-01

    NASA structural materials engineer, Jonathan Lee, displays blocks and pistons as examples of some of the uses for NASA's patented high-strength aluminum alloy originally developed at Marshall Space Flight Center in Huntsville, Alabama. NASA desired an alloy for aerospace applications with higher strength and wear-resistance at elevated temperatures. The alloy is a solution to reduce costs of aluminum engine pistons and lower engine emissions for the automobile industry. The Boats and Outboard Engines Division at Bombardier Recreational Products of Sturtevant, Wisconsin is using the alloy for pistons in its Evinrude E-Tec outboard engine line.

  5. High strength and utilizable ductility of bulk ultrafine-grained Cu-Al alloys

    Science.gov (United States)

    An, X. H.; Han, W. Z.; Huang, C. X.; Zhang, P.; Yang, G.; Wu, S. D.; Zhang, Z. F.

    2008-05-01

    Lack of plasticity is the main drawback for nearly all ultrafine-grained (UFG) materials, which restricts their practical applications. Bulk UFG Cu-Al alloys have been fabricated by using equal channel angular pressing technique. Its ductility was improved to exceed the criteria for structural utility while maintaining a high strength by designing the microstructure via alloying. Factors resulting in the simultaneously enhanced strength and ductility of UFG Cu-Al alloys are the formation of deformation twins and their extensive intersections facilitating accumulation of dislocations.

  6. Aspects of flexural behavior of high strength concrete elements with or without steel fibers

    Directory of Open Access Journals (Sweden)

    Gheorghe-Alexandru Bărbos

    2013-06-01

    Full Text Available Steel fiber reinforced high strength concrete (SFRHSC is concrete made of hydraulic cements containing fine or fine and coarse aggregate and discontinuous discrete steel fibers. In tension, SFRHSC fails only after the steel fiber breaks or is pulled out of the cement matrix. A more general and current approach to the mechanics of fiber reinforcing assumes a crack arrest mechanism based on fracture mechanics. In this model, the energy to extend a crack and debond the fibers in the matrix relates to the properties of the composite. The designers may best view SFRHSC as a concrete with increased strain capacity, impact resistance, energy absorption, fatigue endurance and tensile strength.

  7. Span-to-depth ratio effect on shear strength of steel fiber-reinforced high-strength concrete deep beams using ANN model

    Science.gov (United States)

    Naik, Uday; Kute, Sunil

    2013-12-01

    The paper predicts the shear strength of high-strength steel fiber-reinforced concrete deep beams. It studies the effect of clear span-to-overall depth ratio on shear capacity of steel fiber high-strength deep beams using artificial neural network (ANN8). The three-layered model has eight input nodes which represent width, effective depth, volume fraction, fiber aspect ratio and shear span-to-depth ratio, longitudinal steel, compressive strength of concrete, and clear span-to-overall depth ratio. The model predicts the shear strength of high-strength steel fiber deep beams to be reasonably good when compared with the results of proposed equations by researchers as well as the results obtained by neural network (ANN7) which is developed for seven inputs excluding span-to-depth ratio. The developed neural network ANN8 proves the versatility of artificial neural networks to establish the relations between various parameters affecting complex behavior of steel fiber-reinforced concrete deep beams and costly experimental processes.

  8. High-intensity strength training improves function of chronically painful muscles

    DEFF Research Database (Denmark)

    Andersen, Lars L; Andersen, Christoffer H; Skotte, Jørgen H

    2014-01-01

    AIM: This study investigates consequences of chronic neck pain on muscle function and the rehabilitating effects of contrasting interventions. METHODS: Women with trapezius myalgia (MYA, n = 42) and healthy controls (CON, n = 20) participated in a case-control study. Subsequently MYA were...... randomized to 10 weeks of specific strength training (SST, n = 18), general fitness training (GFT, n = 16), or a reference group without physical training (REF, n = 8). Participants performed tests of 100 consecutive cycles of 2 s isometric maximal voluntary contractions (MVC) of shoulder elevation followed...... capacity during repetitive MVC of the trapezius muscle than healthy controls. High-intensity strength training effectively improves strength capacity during repetitive MVC of the painful trapezius muscle....

  9. High-Strength Composite Fabric Tested at Structural Benchmark Test Facility

    Science.gov (United States)

    Krause, David L.

    2002-01-01

    Large sheets of ultrahigh strength fabric were put to the test at NASA Glenn Research Center's Structural Benchmark Test Facility. The material was stretched like a snare drum head until the last ounce of strength was reached, when it burst with a cacophonous release of tension. Along the way, the 3-ft square samples were also pulled, warped, tweaked, pinched, and yanked to predict the material's physical reactions to the many loads that it will experience during its proposed use. The material tested was a unique multi-ply composite fabric, reinforced with fibers that had a tensile strength eight times that of common carbon steel. The fiber plies were oriented at 0 and 90 to provide great membrane stiffness, as well as oriented at 45 to provide an unusually high resistance to shear distortion. The fabric's heritage is in astronaut space suits and other NASA programs.

  10. High Tensile Strength Amalgams for In-Space Fabrication and Repair

    Science.gov (United States)

    Grugel, Richard N.

    2006-01-01

    Amalgams are well known for their use in dental practice as a tooth filling material. They have a number of useful attributes that include room temperature fabrication, corrosion resistance, dimensional stability, and very good compressive strength. These properties well serve dental needs but, unfortunately, amalgams have extremely poor tensile strength, a feature that severely limits other potential applications. Improved material properties (strength and temperature) of amalgams may have application to the freeform fabrication of repairs or parts that might be necessary during an extended space mission. Advantages would include, but are not limited to: the ability to produce complex parts, a minimum number of processing steps, minimum crew interaction, high yield - minimum wasted material, reduced gravity compatibility, minimum final finishing, safety, and minimum power consumption. The work presented here shows how the properties of amalgams can be improved by changing particle geometries in conjunction with novel engineering metals.

  11. High Tensile Strength Amalgams for In-Space Repair and Fabrication

    Science.gov (United States)

    Grugel, R. N.

    2005-01-01

    Amalgams are defined as an alloy of mercury with one or more other metals. These, along with those based on gallium (also liquid at near room temperature), are widely used in dental practice as a tooth filling material. Amalgams have a number of useful attributes that indude room temperature compounding. corrosion resistance, dimensional stability, and good compressive strength. These properties well serve dental needs but, unfortunately, amalgams have extremely poor tensile strength, a feature that severely limits their applications. The work presented here demonstrates how, by modifying particle geometry, the tensile strength of amalgams can be increased and thus extending the range of potential applications. This is relevant to, for example, the freeform fabrication of replacement parts that might be necessary during an extended space mission. Advantages, i.e. Figures-of-Merit. include the ability to produce complex parts, minimum crew interaction, high yield - minimum wasted material, reduced gravity compatibility, minimum final finishing, safety, and minimum power consumption.

  12. Applicability of newly developed 610MPa class heavy thickness high strength steel to boiler pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Norihiko; Kaihara, Shoichiro; Ishii, Jun [Ishikawajima-Harima Heavy Industries Corp., Yokohama (Japan); Kajigaya, Ichiro [Ishikawajima-Harima Heavy Industries Corp., Tokyo (Japan); Totsuka, Takehiro; Miyazaki, Takashi [Ishikawajima-Harima Heavy Industries Corp., Aioi (Japan)

    1995-11-01

    Construction of a 350 MW Class PFBC (Pressurized Fluidized Bed Combustion) boiler plant is under planning in Japan. Design temperature and pressure of the vessel are maximum 350 C and 1.69 MPa, respectively. As the plate thickness of the vessel exceeds over 100 mm, high strength steel plate of good weldability and less susceptible to reheat cracking was required and developed. The steel was aimed to satisfy the tensile strength over 610 MPa at 350 C after postweld heat treatment (PWHT), with good notch toughness. The authors investigated the welding performances of the newly developed steel by using 150 mm-thick plate welded by pulsed-MAG and SAW methods. It was confirmed that the newly developed steel and its welds possess sufficient strength and toughness after PWHT, and applicable to the actual pressure vessel.

  13. Behavior of bonded and unbonded prestressed normal and high strength concrete beams

    Directory of Open Access Journals (Sweden)

    O.F. Hussien

    2012-12-01

    This paper presents an experimental program conducted to study the behavior of bonded and unbounded prestressed normal strength (NSC and high strength concrete (HSC beams. The program consists of a total of nine beams; two specimens were reinforced with non-prestressed reinforcement, four specimens were reinforced with bonded tendons, and the remaining three specimens were reinforced with unbonded tendons. The overall dimensions of the beams are 160 × 340 × 4400-mm. The beams were tested under cyclic loading up to failure to examine its flexural behavior. The main variables in this experimental program are nominal concrete compressive strength (43, 72 and 97 MPa, bonded and unbonded tendons and prestressing index (0%, 70% and 100%. Theoretical analysis using rational approach was also carried out to predict the flexural behavior of the specimens. Evaluation of the analytical work is introduced and compared to the results of the experimental work.

  14. Structural optimization of 3D-printed synthetic spider webs for high strength.

    Science.gov (United States)

    Qin, Zhao; Compton, Brett G; Lewis, Jennifer A; Buehler, Markus J

    2015-05-15

    Spiders spin intricate webs that serve as sophisticated prey-trapping architectures that simultaneously exhibit high strength, elasticity and graceful failure. To determine how web mechanics are controlled by their topological design and material distribution, here we create spider-web mimics composed of elastomeric filaments. Specifically, computational modelling and microscale 3D printing are combined to investigate the mechanical response of elastomeric webs under multiple loading conditions. We find the existence of an asymptotic prey size that leads to a saturated web strength. We identify pathways to design elastomeric material structures with maximum strength, low density and adaptability. We show that the loading type dictates the optimal material distribution, that is, a homogeneous distribution is better for localized loading, while stronger radial threads with weaker spiral threads is better for distributed loading. Our observations reveal that the material distribution within spider webs is dictated by the loading condition, shedding light on their observed architectural variations.

  15. Estimating Compressive Strength of High Performance Concrete with Gaussian Process Regression Model

    Directory of Open Access Journals (Sweden)

    Nhat-Duc Hoang

    2016-01-01

    Full Text Available This research carries out a comparative study to investigate a machine learning solution that employs the Gaussian Process Regression (GPR for modeling compressive strength of high-performance concrete (HPC. This machine learning approach is utilized to establish the nonlinear functional mapping between the compressive strength and HPC ingredients. To train and verify the aforementioned prediction model, a data set containing 239 HPC experimental tests, recorded from an overpass construction project in Danang City (Vietnam, has been collected for this study. Based on experimental outcomes, prediction results of the GPR model are superior to those of the Least Squares Support Vector Machine and the Artificial Neural Network. Furthermore, GPR model is strongly recommended for estimating HPC strength because this method demonstrates good learning performance and can inherently express prediction outputs coupled with prediction intervals.

  16. A Pilot Feasibility Study of Oral 5-Fluorocytosine and Genetically-Modified Neural Stem Cells Expressing E.Coli Cytosine Deaminase for Treatment of Recurrent High Grade Gliomas

    Science.gov (United States)

    2017-11-07

    Adult Anaplastic Astrocytoma; Recurrent Grade III Glioma; Recurrent Grade IV Glioma; Adult Anaplastic Oligodendroglioma; Adult Brain Tumor; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Mixed Glioma; Recurrent Adult Brain Tumor; Adult Anaplastic Oligoastrocytoma; Recurrent High Grade Glioma

  17. Properties of Cement Mortar and Ultra-High Strength Concrete Incorporating Graphene Oxide Nanosheets.

    Science.gov (United States)

    Lu, Liulei; Ouyang, Dong

    2017-07-20

    In this work, the effect of graphene oxide nanosheet (GONS) additives on the properties of cement mortar and ultra-high strength concrete (UHSC) is reported. The resulting GONS-cement composites were easy to prepare and exhibited excellent mechanical properties. However, their fluidity decreased with increasing GONS content. The UHSC specimens were prepared with various amounts of GONSs (0-0.03% by weight of cement). Results indicated that using 0.01% by weight of cement GONSs caused a 7.82% in compressive strength after 28 days of curing. Moreover, adding GONSs improved the flexural strength and deformation ability, with the increase in flexural strength more than that of compressive strength. Furthermore, field-emission scanning electron microscopy (FE-SEM) was used to observe the morphology of the hardened cement paste and UHSC samples. FE-SEM observations showed that the GONSs were well dispersed in the matrix and the bonding of the GONSs and the surrounding cement matrix was strong. Furthermore, FE-SEM observation indicated that the GONSs probably affected the shape of the cement hydration products. However, the growth space for hydrates also had an important effect on the morphology of hydrates. The true hydration mechanism of cement composites with GONSs needs further study.

  18. Properties of Cement Mortar and Ultra-High Strength Concrete Incorporating Graphene Oxide Nanosheets

    Directory of Open Access Journals (Sweden)

    Liulei Lu

    2017-07-01

    Full Text Available In this work, the effect of graphene oxide nanosheet (GONS additives on the properties of cement mortar and ultra-high strength concrete (UHSC is reported. The resulting GONS-cement composites were easy to prepare and exhibited excellent mechanical properties. However, their fluidity decreased with increasing GONS content. The UHSC specimens were prepared with various amounts of GONSs (0–0.03% by weight of cement. Results indicated that using 0.01% by weight of cement GONSs caused a 7.82% in compressive strength after 28 days of curing. Moreover, adding GONSs improved the flexural strength and deformation ability, with the increase in flexural strength more than that of compressive strength. Furthermore, field-emission scanning electron microscopy (FE-SEM was used to observe the morphology of the hardened cement paste and UHSC samples. FE-SEM observations showed that the GONSs were well dispersed in the matrix and the bonding of the GONSs and the surrounding cement matrix was strong. Furthermore, FE-SEM observation indicated that the GONSs probably affected the shape of the cement hydration products. However, the growth space for hydrates also had an important effect on the morphology of hydrates. The true hydration mechanism of cement composites with GONSs needs further study.

  19. Alloy and composition dependence of hydrogen embrittlement susceptibility in high-strength steel fasteners.

    Science.gov (United States)

    Brahimi, S V; Yue, S; Sriraman, K R

    2017-07-28

    High-strength steel fasteners characterized by tensile strengths above 1100 MPa are often used in critical applications where a failure can have catastrophic consequences. Preventing hydrogen embrittlement (HE) failure is a fundamental concern implicating the entire fastener supply chain. Research is typically conducted under idealized conditions that cannot be translated into know-how prescribed in fastener industry standards and practices. Additionally, inconsistencies and even contradictions in fastener industry standards have led to much confusion and many preventable or misdiagnosed fastener failures. HE susceptibility is a function of the material condition, which is comprehensively described by the metallurgical and mechanical properties. Material strength has a first-order effect on HE susceptibility, which increases significantly above 1200 MPa and is characterized by a ductile--brittle transition. For a given concentration of hydrogen and at equal strength, the critical strength above which the ductile-brittle transition begins can vary due to second-order effects of chemistry, tempering temperature and sub-microstructure. Additionally, non-homogeneity of the metallurgical structure resulting from poorly controlled heat treatment, impurities and non-metallic inclusions can increase HE susceptibility of steel in ways that are measurable but unpredictable. Below 1200 MPa, non-conforming quality is often the root cause of real-life failures.This article is part of the themed issue 'The challenges of hydrogen and metals'. © 2017 The Author(s).

  20. High efficient and continuous surface modification of carbon fibers with improved tensile strength and interfacial adhesion

    Science.gov (United States)

    Sun, Jingfeng; Zhao, Feng; Yao, Yue; Jin, Zhen; Liu, Xu; Huang, Yudong

    2017-08-01

    Most of the surface modification technologies for carbon fibers, no matter in laboratory scale or for commercial manufacture, are accompanied by a simultaneous decrease in tensile strength. In this paper, a feasible and high efficient strategy for carbon fiber treatment which could obviously improve both tensile strength and interfacial adhesion was proposed. Continuously moving carbon fibers were treated with atmospheric helium plasma for 1 min, followed by a 5 min pyrolytic carbon deposition using ethanol as precursor at 800 °C. The effects of the new approach were characterized by SEM, AFM, nanoindentation, XPS, Raman, wettability analysis, single fiber tensile strength testing and single fiber pull-out testing. After modification, pyrolytic carbon coating was deposited on the fiber surface uniformly, and the roughness and surface energy increased significantly. The single fiber tensile testing results indicate that the resulting fiber strength increased 15.7%, rising from 3.13 to 3.62 GPa. Meanwhile, the interfacial shear strength of its epoxy composites increased from 65.3 to 83.5 MPa. The comparative studies of carbon fibers modified with commercial anodic oxidation and sizing were also carried out. The results demonstrate that the new method can be utilized in the carbon fiber manufacture process and is more efficient than the traditional approaches.