46 CFR 57.06-4 - Production testing specimen requirements.

Science.gov (United States)

2010-10-01

... WELDING AND BRAZING Production Tests § 57.06-4 Production testing specimen requirements. (a) For test... 46 Shipping 2 2010-10-01 2010-10-01 false Production testing specimen requirements. 57.06-4... to welding shall not throw the finished test plate out of line by an angle of over 5°. (c) Where the...

Low upper-shelf toughness, high transition temperature test insert in HSST [Heavy Section Steel Technology] PTSE-2 [Pressurized Thermal Shock Experiment-2] vessel and wide plate test specimens: Final report

International Nuclear Information System (INIS)

Domian, H.A.

1987-02-01

A piece of A387, Grade 22 Class 2 (2-1/4 Cr - 1 Mo) steel plate specially heat treated to produce low upper-shelf (LUS) toughness and high transition temperature was installed in the side wall of Heavy Section Steel Technology (HHST) vessel V-8. This vessel is to be tested by the Oak Ridge National Laboratory (ORNL) in the Pressurized Thermal Shock Experiment-2 (PTSE-2) project of the HSST program. Comparable pieces of the plate were made into six wide plate specimens and other samples. These samples underwent tensile tests, Charpy tests, and J-integral tests. The results of these tests are given in this report

On the Performance of X-ray Imaging Plates in Gamma Radiography employing Reactor-produced Radioisotopes

Science.gov (United States)

Silvani, Maria Ines; de Almeida, Gevaldo L.; Furieri, Rosanne C.; Lopes, Ricardo T.

2011-08-01

Gamma-radiography employing radiographic films is a well established technique for non-destructive assays. The advent of X-ray sensitive Imaging Plates opens up new possibilities to apply this technique thanks to the advantages exhibited by this new device. Indeed, besides a sensitivity about 20 times higher then the conventional photographic film, requiring thus a shorter exposure time, it does not require a dark room for a cumbersome and time-consuming chemical processing associated to the development, an can be erased to be reused many times. Moreover, its development carried out by means of a laser beam produces digitalized images which can be promptly stored in a computer. Although its resolution is still poorer than that of the conventional film, those advantages overwhelms this specific parameter when it is not an essential feature for the intended application. This work evaluates the feasibility of employing X-ray Imaging Plates as detector for higher photon energies as those emitted by reactor-produced radioisotopes. Within this frame, radioisotopes such as 198Au and 56Mn, produced at the Argonauta research reactor in the Instituto de Engenharia Nuclear-CNEN have been employed as sources to acquire radiographic images of several pieces of equipment, devices and components. In order to keep the source appearance—with regard to the detector—as punctual as possible, reducing hence the penumbra effect, the mass of the irradiated material had to be limited. Therefore, due to the low neutron flux available at the main port of the reactor, the exposure times have to be extended along several hours or even a couple of days in order to reach an image with adequate contrast. This demand, nevertheless, does not constitute a serious hindrance as the exposure process can be carried out without any intervention or surveillance. Results have shown that in spite of the higher photon energies used, surpassing the X-ray range for which the imaging plates have been

Towards stacked zone plates

International Nuclear Information System (INIS)

Werner, S; Rehbein, S; Guttman, P; Heim, S; Schneider, G

2009-01-01

Fresnel zone plates are the key optical elements for soft and hard x-ray microscopy. For short exposure times and minimum radiation load of the specimen the diffraction efficiency of the zone plate objectives has to be maximized. As the efficiency strongly depends on the height of the diffracting zone structures the achievable aspect ratio of the nanostructures determines these limits. To reach aspect ratios ≥ 20:1 for high efficient optics we propose to superimpose zone plates on top of each other. With this multiplication approach the final aspect ratio is only limited by the number of stacked zone plate layers. For the stack process several nanostructuring process steps have to be developed and/or improved. Our results show for the first time two layers of zone plates stacked on top of each other.

MLEP-Fail calibration for 1/8 inch thick cast plate of 17-4 steel.

Energy Technology Data Exchange (ETDEWEB)

Corona, Edmundo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-02-01

The purpose of the work presented in this memo was to calibrate the Sierra material model Multilinear Elastic-Plastic Hardening Model with Failure (MLEP-Fail) for 1/8 inch thick cast plate of 17-4 steel. The calibration approach is essentially the same as that recently used in a previous memo using data from smooth and notched tensile specimens. The notched specimens were manufactured with three notch radii R = 1=8, 1/32 and 1/64 inches. The dimensions of the smooth and notched specimens are given in the prints in Appendix A. Two cast plates, Plate 3 and Plate 4, with nominally identical properties were considered.

Prediction of crack growth direction by Strain Energy Sih's Theory on specimens SEN under tension-compression biaxial loading employing Genetic Algorithms

International Nuclear Information System (INIS)

Rodriguez-MartInez R; Lugo-Gonzalez E; Urriolagoitia-Calderon G; Urriolagoitia-Sosa G; Hernandez-Gomez L H; Romero-Angeles B; Torres-San Miguel Ch

2011-01-01

Crack growth direction has been studied in many ways. Particularly Sih's strain energy theory predicts that a fracture under a three-dimensional state of stress spreads in direction of the minimum strain energy density. In this work a study for angle of fracture growth was made, considering a biaxial stress state at the crack tip on SEN specimens. The stress state applied on a tension-compression SEN specimen is biaxial one on crack tip, as it can observed in figure 1. A solution method proposed to obtain a mathematical model considering genetic algorithms, which have demonstrated great capacity for the solution of many engineering problems. From the model given by Sih one can deduce the density of strain energy stored for unit of volume at the crack tip as dW = [1/2E(σ 2 x + σ 2 y ) - ν/E(σ x σy)]dV (1). From equation (1) a mathematical deduction to solve in terms of θ of this case was developed employing Genetic Algorithms, where θ is a crack propagation direction in plane x-y. Steel and aluminium mechanical properties to modelled specimens were employed, because they are two of materials but used in engineering design. Obtained results show stable zones of fracture propagation but only in a range of applied loading.

Implant Material, Type of Fixation at the Shaft, and Position of Plate Modify Biomechanics of Distal Femur Plate Osteosynthesis.

Science.gov (United States)

Kandemir, Utku; Augat, Peter; Konowalczyk, Stefanie; Wipf, Felix; von Oldenburg, Geert; Schmidt, Ulf

2017-08-01

To investigate whether (1) the type of fixation at the shaft (hybrid vs. locking), (2) the position of the plate (offset vs. contact) and (3) the implant material has a significant effect on (a) construct stiffness and (b) fatigue life in a distal femur extraarticular comminuted fracture model using the same design of distal femur periarticular locking plate. An extraarticular severely comminuted distal femoral fracture pattern (OTA/AO 33-A3) was simulated using artificial bone substitutes. Ten-hole distal lateral femur locking plates were used for fixation per the recommended surgical technique. At the distal metaphyseal fragment, all possible locking screws were placed. For the proximal diaphyseal fragment, different types of screws were used to create 4 different fixation constructs: (1) stainless steel hybrid (SSH), (2) stainless steel locked (SSL), (3) titanium locked (TiL), and (4) stainless steel locked with 5-mm offset at the diaphysis (SSLO). Six specimens of each construct configuration were tested. First, each specimen was nondestructively loaded axially to determine the stiffness. Then, each specimen was cyclically loaded with increasing load levels until failure. Construct Stiffness: The fixation construct with a stainless steel plate and hybrid fixation (SSH) had the highest stiffness followed by the construct with a stainless steel plate and locking screws (SSL) and were not statistically different from each other. Offset placement (SSLO) and using a titanium implant (TiL) significantly reduced construct stiffness. Fatigue Failure: The stainless steel with hybrid fixation group (SSH) withstood the most number of cycles to failure and higher loads, followed by the stainless steel plate and locking screw group (SSL), stainless steel plate with locking screws and offset group (SSLO), and the titanium plate and locking screws group (TiL) consecutively. Offset placement (SSLO) as well as using a titanium implant (TiL) reduced cycles to failure. Using the

THE EFFECT OF SUPPORT PLATE ON DRILLING-INDUCED DELAMINATION

Directory of Open Access Journals (Sweden)

Navid Zarif Karimi

2016-02-01

Full Text Available Delamination is considered as a major problem in drilling of composite materials, which degrades the mechanical properties of these materials. The thrust force exerted by the drill is considered as the major cause of delamination; and one practical approach to reduce delamination is to use a back-up plate under the specimen. In this paper, the effect of exit support plate on delamination in twist drilling of glass fiber reinforced composites is studied. Firstly, two analytical models based on linear fracture mechanics and elastic bending theory of plates are described to find critical thrust forces at the beginning of crack growth for drilling with and without back-up plate. Secondly, two series of experiments are carried out on glass fiber reinforced composites to determine quantitatively the effect of drilling parameters on the amount of delamination. Experimental findings verify a large reduction in the amount of delaminated area when a back-up plate is placed under the specimen.

Effect of heat treatment on wear resistance of a grinding plate ...

African Journals Online (AJOL)

Some of the specimens were quenched in water and palm oil, while some of the quenched specimens were tempered at 200°C. The results obtained were corroborated with the microstructure of the specimens examined under an optical microscope. The hardness values of the grinding plate specimens quenched in ...

Biaxial Testing of 2195 Aluminum Lithium Alloy Using Cruciform Specimens

Science.gov (United States)

Johnston, W. M.; Pollock, W. D.; Dawicke, D. S.; Wagner, John A. (Technical Monitor)

2002-01-01

A cruciform biaxial test specimen was used to test the effect of biaxial load on the yield of aluminum-lithium alloy 2195. Fifteen cruciform specimens were tested from 2 thicknesses of 2195-T8 plate, 0.45 in. and 1.75 in. These results were compared to the results from uniaxial tensile tests of the same alloy, and cruciform biaxial tests of aluminum alloy 2219-T87.

Earth's Decelerating Tectonic Plates

Energy Technology Data Exchange (ETDEWEB)

Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

2008-08-22

Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

X-ray microscopy with high resolution zone plates -- Recent developments

International Nuclear Information System (INIS)

Schneider, G.; Wilhein, T.; Niemann, B.; Guttmann, P.

1995-01-01

In order to expand the applications of X-ray microscopy, developments in the fields of zone plate technology, specimen preparation and imaging techniques have been made. A new cross-linked polymer chain electron beam resist allows to record zone plate pattern down to 19 nm outermost zone width. High resolution zone plates in germanium with outermost zone widths down to 19 nm have been developed. In addition, phase zone plates in nickel down to 30 nm zone width have been made by electroplating. In order to enhance the image contrast for weak absorbing objects, the phase contrast method for X-ray microscopy was developed and implemented on the Goettingen X-ray microscope at BESSY. The effects of X-ray absorption on the structure of biological specimen limits the maximum applicable radiation dose and therefore the achievable signal to noise ratio for an artifact-free X-ray image. To improve the stability especially of biological specimen, a cryogenic object chamber has been developed and tested. It turns out that at the operating temperature T ≤ 130 K unfixed biological specimen can be exposed to a radiation dose of 10 9 --10 10 Gy without any observable structural changes. A multiple-angle viewing stage allows to take stereoscopic images with the X-ray microscope, giving a 3D-impression of the object

Analysis of ductile-brittle transition shifts for standard and miniature bending specimens of irradiated steel

International Nuclear Information System (INIS)

Korshunov, M.E.; Korolev, Yu.N.; Krasikov, E.A.; Gabuev, N.N.; Tykhmeev, D.Yu.

1996-01-01

A study is made to reveal if there is a correlation between shifts in temperature curves obtained when testing thin plates and standard specimens on impact bending and fracture toughness. The tests were carried out using steel 25Kh3NM specimens irradiated by 6 x 10 19 cm -2 neutron fluence. A conclusion is made about the possibility to evaluate the degree of radiation-induced embrittlement of reactor steels on the basis of thin plate testing under quasistatic loads [ru

Fire resistance of a steel plate reinforced concrete bearing wall

International Nuclear Information System (INIS)

Kodaira, Akio; Kanchi, Masaki; Fujinaka, Hideo; Akita, Shodo; Ozaki, Masahiko

2003-01-01

Samples from a steel plate reinforced concrete bearing wall composed of concrete slab sandwiched between studded steel plates, were subjected to loaded fire resistance tests. There were two types of specimens: some were 1800 mm high while the rest were 3000 mm high ; thickness and width were the same for all specimens, at 200 mm and 800 mm, respectively. Under constant load conditions, one side of each specimen was heated along the standard fire-temperature curve. The results enabled us to approximate the relationship between the ratio of working load to concrete strength N/(Ac x c σ b) and the fire resistance time (t: minutes), as equation (1) for the 1800 mm - high specimen, and equation (2) for the 3000 mm - high specimen. N/(Ac x c σ b) = 2.21 x (1/t) 0.323 (1), .N/(Ac x c σ b) 2.30 x (1/t) 0.378 (2) In addition, the temperature of the unheated side of the specimens was 100degC at 240 minutes of continuous heating, clearly indicating that there was sufficient heat insulation. (author)

Ex vivo biomechanical evaluation of pigeon (Columba livia) cadaver intact humeri and ostectomized humeri stabilized with caudally applied titanium locking plate or stainless steel nonlocking plate constructs.

Science.gov (United States)

Darrow, Brett G; Biskup, Jeffrey J; Weigel, Joseph P; Jones, Michael P; Xie, Xie; Liaw, Peter K; Tharpe, Josh L; Sharma, Aashish; Penumadu, Dayakar

2017-05-01

OBJECTIVE To evaluate mechanical properties of pigeon (Columba livia) cadaver intact humeri versus ostectomized humeri stabilized with a locking or nonlocking plate. SAMPLE 30 humeri from pigeon cadavers. PROCEDURES Specimens were allocated into 3 groups and tested in bending and torsion. Results for intact pigeon humeri were compared with results for ostectomized humeri repaired with a titanium 1.6-mm screw locking plate or a stainless steel 1.5-mm dynamic compression plate; the ostectomized humeri mimicked a fracture in a thin cortical bone. Locking plates were secured with locking screws (2 bicortical and 4 monocortical), and nonlocking plates were secured with bicortical nonlocking screws. Constructs were cyclically tested nondestructively in 4-point bending and then tested to failure in bending. A second set of constructs were cyclically tested non-destructively and then to failure in torsion. Stiffness, strength, and strain energy of each construct were compared. RESULTS Intact specimens were stiffer and stronger than the repair groups for all testing methods, except for nonlocking constructs, which were significantly stiffer than intact specimens under cyclic bending. Intact bones had significantly higher strain energies than locking plates in both bending and torsion. Locking and nonlocking plates were of equal strength and strain energy, but not stiffness, in bending and were of equal strength, stiffness, and strain energy in torsion. CONCLUSIONS AND CLINICAL RELEVANCE Results for this study suggested that increased torsional strength may be needed before bone plate repair can be considered as the sole fixation method for avian species.

Specimen Machining for the Study of the Effect of Swelling on CGR in PWR Environment.

Energy Technology Data Exchange (ETDEWEB)

Teysseyre, Sebastien Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-06-01

This report describes the preparation of ten specimens to be used for the study of the effect of swelling on the propagation of irradiation assisted stress corrosion cracking cracks. Four compact tension specimens, four microscopy plates and two tensile specimens were machined from a AISI 304 material that was irradiated up to 33 dpa. The specimens had been machined such as to represent the behavior of materials with 3.7%swelling and <2% swelling.

Prediction of crack growth direction by Strain Energy Sih's Theory on specimens SEN under tension-compression biaxial loading employing Genetic Algorithms

Energy Technology Data Exchange (ETDEWEB)

Rodriguez-MartInez R; Lugo-Gonzalez E; Urriolagoitia-Calderon G; Urriolagoitia-Sosa G; Hernandez-Gomez L H; Romero-Angeles B; Torres-San Miguel Ch, E-mail: rrodriguezm@ipn.mx, E-mail: urrio332@hotmail.com, E-mail: guiurri@hotmail.com, E-mail: luishector56@hotmail.com, E-mail: romerobeatriz98@hotmail.com, E-mail: napor@hotmail.com [INSTITUTO POLITECNICO NACIONAL Seccion de Estudios de Posgrado e Investigacion (SEPI), Escuela Superior de Ingenieria Mecanica y Electrica (ESIME), Edificio 5. 2do Piso, Unidad Profesional Adolfo Lopez Mateos ' Zacatenco' Col. Lindavista, C.P. 07738, Mexico, D.F. (Mexico)

2011-07-19

Crack growth direction has been studied in many ways. Particularly Sih's strain energy theory predicts that a fracture under a three-dimensional state of stress spreads in direction of the minimum strain energy density. In this work a study for angle of fracture growth was made, considering a biaxial stress state at the crack tip on SEN specimens. The stress state applied on a tension-compression SEN specimen is biaxial one on crack tip, as it can observed in figure 1. A solution method proposed to obtain a mathematical model considering genetic algorithms, which have demonstrated great capacity for the solution of many engineering problems. From the model given by Sih one can deduce the density of strain energy stored for unit of volume at the crack tip as dW = [1/2E({sigma}{sup 2}{sub x} + {sigma}{sup 2}{sub y}) - {nu}/E({sigma}{sub x}{sigma}{sub y})]dV (1). From equation (1) a mathematical deduction to solve in terms of {theta} of this case was developed employing Genetic Algorithms, where {theta} is a crack propagation direction in plane x-y. Steel and aluminium mechanical properties to modelled specimens were employed, because they are two of materials but used in engineering design. Obtained results show stable zones of fracture propagation but only in a range of applied loading.

Plating on Zircaloy-2

International Nuclear Information System (INIS)

Dini, J.W.; Johnson, H.R.; Jones, A.

1979-03-01

Zircaloy-2 is a difficult alloy to coat with an adherent electroplate because it easily forms a tenacious oxide film in air and aqueous solutions. Procedures reported in the literature and those developed at SLL for surmounting this problem were investigated. The best results were obtained when specimens were first etched in either an ammonium bifluoride/sulfuric acid or an ammonium bifluoride solution, plated, and then heated at 700 0 C for 1 hour in a constrained condition. Machining threads in the Zircaloy-2 for the purpose of providing sites for mechanical interlocking of the plating also proved satisfactory

Plating on stainless steel alloys

International Nuclear Information System (INIS)

Dini, J.W.; Johnson, H.R.

1981-01-01

Quantitative adhesion data are presented for a variety of electroplated stainless steel type alloys. Results show that excellent adhesion can be obtained by using a Wood's nickel strike or a sulfamate nickel strike prior to final plating. Specimens plated after Wood's nickel striking failed in the deposit rather than at the interface between the substrate and the coating. Flyer plate quantitative tests showed that use of anodic treatment in sulfuric acid prior to Wood's nickel striking even further improved adhesion. In contrast activation of stainless steels by immersion or cathodic treatment in hydrochloric acid resulted in very reduced bond strengths with failure always occurring at the interface between the coating and substrate

Nondestructive evaluation of wall thinning occurred under reinforced plate by MFL method

International Nuclear Information System (INIS)

Kikuchi, Hiroaki; Sato, Kaito; Shimizu, Isamu

2013-01-01

Basic study on applying magnetic flux leakage (MFL) method using ac excitation to a nondestructive evaluation of wall thinning occurred under reinforcing plates in nuclear power plants were performed. Frequently, MFL method by means of dc field for exciting specimens is adopted, and only intensity of magnetic flux density is evaluated. On the other hand, MFL with alternating current enable us to utilize not only amplitude of magnetic flux density but also phase difference, which contributes to evaluation with higher accuracy. Here, specimens with slit and pipe with imitated wall thinning are prepared and magnetized using magnetic yoke with ac field, and then the leakage magnetic flux density and the phase difference on the specimen surface are investigated. Additionally, specimens imitated wall thinning occurred under reinforcing plates were investigated by MFL with ac excitation. (author)

[Development of polyaxial locking plate screw system of sacroiliac joint].

Science.gov (United States)

Fan, Weijie; Xie, Xuesong; Zhou, Shuping; Zhang, Yonghu

2014-09-01

To develop an instrument for sacroiliac joint fixation with less injury and less complications. Firstly, 18 adult pelvic specimens (8 males and 10 females) were used to measure the anatomical data related to the locking plates and locking screws on the sacrum and ilium, and the polyaxial locking plate screw system of the sacroiliac joint was designed according to the anatomic data. This system was made of medical titanium alloy. Then 4 adult male plevic specimens were harvested and the experiment was divided into 3 groups: group A (normal pelvic), group B (the dislocated sacroiliac joint fixed with sacroiliac screws), and group C (the dislocated sacroiliac joint fixed with polyaxial locking plate screw system). The vertical displacement of sacroiliac joint under the condition of 0-700 N vertical load and the horizontal displacement on angle under the condition of 0-12 N·m torsional load were compared among the 3 groups by using the biological material test system. Finally, the simulated application test was performed on 1 adult male cadaveric specimen to observe soft tissue injury and the position of the locking plate and screw by X-ray films. According to the anatomic data of the sacrum and ilium, the polyaxial locking plate screw system of the sacroiliac joint was designed. The biomechanical results showed that the vertical displacement of the sacroiliac joint under the condition of 0-700 N vertical load in group A was significantly bigger than that in group B and group C (P 0.05). The horizontal displacement on angle under the condition of 0-12 N·m torsional load in group A was significantly less than that in group B and group C (P 0.05). The test of simulating application showed that the specimen suffered less soft tissue injury, and this instrument could be implanted precisely and safely. The polyaxial locking plate screw system of the sacroiliac joint has the advantages of smaller volume and less injury; polyaxial fixation enables flexible adjustment screw

On indoor radon contamination monitoring with SSNTDs: Experimental results concerning plate-out and self-plate-out effects

International Nuclear Information System (INIS)

Bigazzi, G.; Hadler, J.C.; Paulo, S.R.

1989-01-01

Measurements of the alpha activities of 222 Rn and its daughters were performed, both inside a glass recipient and in closed rooms, employing SSNTDs (CR-39 and nuclear emulsion). The experimental results presented here show that plate-out and self-plate-out effects should be taken into account when SSNTDs are employed in indoor radon contamination monitoring. (orig.)

Summary of HSST wide-plate crack-arrest tests and analyses

International Nuclear Information System (INIS)

Naus, D.J.; Bass, B.R.; Keeney-Walker, J.; Fields, R.J.; DeWit, R.; Low, S.R. III

1988-01-01

Eleven wide-plate crack-arrest tests have been completed to date, seven utilizing specimens fabricated from A533B class 1 material (WP-1 series), and four fabricated from a low upper-shelf base material (WP-2 series). With the exception of one test in the WP-1 series and two tests in the WP-2 series which utilized 152-mm-thick specimens, each test utilized a single-edge notched (SEN) plate specimen 1 by 1 by 0.1 m that was subjected to a linear thermal gradient along the plane of crack propagation. Test results exhibit an increase in crack-arrest toughness with temperature, with the rate of increase becoming greater as the temperature increases. When the wide-place test results are combined with other large-specimen results (Japanese ESSO, thermal-shock experiments and pressurized-thermal-shock experiments) the data show a consistent trend in which the K Ia data extends above the limit provided in ASME Section XI. (author)

Method and Apparatus for Measuring Thermal Conductivity of Small, Highly Insulating Specimens

Science.gov (United States)

Miller, Robert A (Inventor); Kuczmarski, Maria A (Inventor)

2013-01-01

A method and apparatus for the measurement of thermal conductivity combines the following capabilities: 1) measurements of very small specimens; 2) measurements of specimens with thermal conductivity on the same order of that as air; and, 3) the ability to use air as a reference material. Care is taken to ensure that the heat flow through the test specimen is essentially one-dimensional. No attempt is made to use heated guards to minimize the flow of heat from the hot plate to the surroundings. Results indicate that since large correction factors must be applied to account for guard imperfections when specimen dimensions are small, simply measuring and correcting for heat from the heater disc that does not flow into the specimen is preferable.

Practical aspects of Boersch phase contrast electron microscopy of biological specimens

Energy Technology Data Exchange (ETDEWEB)

Walter, Andreas [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany); Muzik, Heiko; Vieker, Henning; Turchanin, Andrey; Beyer, Andre; Goelzhaeuser, Armin [University of Bielefeld, Physics of Supramolecular Systems and Surfaces, Universitaetsstr. 25, D-33615 Bielefeld (Germany); Lacher, Manfred; Steltenkamp, Siegfried; Schmitz, Sam; Holik, Peter [Caesar Research Center, Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany); Kuehlbrandt, Werner [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany); Rhinow, Daniel, E-mail: daniel.rhinow@biophys.mpg.de [Max-Planck-Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60439 Frankfurt (Germany)

2012-05-15

Implementation of physical phase plates into transmission electron microscopes to achieve in-focus contrast for ice-embedded biological specimens poses several technological challenges. During the last decade several phase plates designs have been introduced and tested for electron cryo-microscopy (cryoEM), including thin film (Zernike) phase plates and electrostatic devices. Boersch phase plates (BPPs) are electrostatic einzel lenses shifting the phase of the unscattered beam by an arbitrary angle. Adjusting the phase shift to 90 Degree-Sign achieves the maximum contrast transfer for phase objects such as biomolecules. Recently, we reported the implementation of a BPP into a dedicated phase contrast aberration-corrected electron microscope (PACEM) and demonstrated its use to generate in-focus contrast of frozen-hydrated specimens. However, a number of obstacles need to be overcome before BPPs can be used routinely, mostly related to the phase plate devices themselves. CryoEM with a physical phase plate is affected by electrostatic charging, obliteration of low spatial frequencies, and mechanical drift. Furthermore, BPPs introduce single sideband contrast (SSB), due to the obstruction of Friedel mates in the diffraction pattern. In this study we address the technical obstacles in detail and show how they may be overcome. We use X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) to identify contaminants responsible for electrostatic charging, which occurs with most phase plates. We demonstrate that obstruction of low-resolution features is significantly reduced by lowering the acceleration voltage of the microscope. Finally, we present computational approaches to correct BPP images for SSB contrast and to compensate for mechanical drift of the BPP. -- Highlights: Black-Right-Pointing-Pointer Various obstacles need to be overcome before Boersch phase plates can be used routinely. Black-Right-Pointing-Pointer Technical problems include

Practical aspects of Boersch phase contrast electron microscopy of biological specimens

International Nuclear Information System (INIS)

Walter, Andreas; Muzik, Heiko; Vieker, Henning; Turchanin, Andrey; Beyer, André; Gölzhäuser, Armin; Lacher, Manfred; Steltenkamp, Siegfried; Schmitz, Sam; Holik, Peter; Kühlbrandt, Werner; Rhinow, Daniel

2012-01-01

Implementation of physical phase plates into transmission electron microscopes to achieve in-focus contrast for ice-embedded biological specimens poses several technological challenges. During the last decade several phase plates designs have been introduced and tested for electron cryo-microscopy (cryoEM), including thin film (Zernike) phase plates and electrostatic devices. Boersch phase plates (BPPs) are electrostatic einzel lenses shifting the phase of the unscattered beam by an arbitrary angle. Adjusting the phase shift to 90° achieves the maximum contrast transfer for phase objects such as biomolecules. Recently, we reported the implementation of a BPP into a dedicated phase contrast aberration-corrected electron microscope (PACEM) and demonstrated its use to generate in-focus contrast of frozen–hydrated specimens. However, a number of obstacles need to be overcome before BPPs can be used routinely, mostly related to the phase plate devices themselves. CryoEM with a physical phase plate is affected by electrostatic charging, obliteration of low spatial frequencies, and mechanical drift. Furthermore, BPPs introduce single sideband contrast (SSB), due to the obstruction of Friedel mates in the diffraction pattern. In this study we address the technical obstacles in detail and show how they may be overcome. We use X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) to identify contaminants responsible for electrostatic charging, which occurs with most phase plates. We demonstrate that obstruction of low-resolution features is significantly reduced by lowering the acceleration voltage of the microscope. Finally, we present computational approaches to correct BPP images for SSB contrast and to compensate for mechanical drift of the BPP. -- Highlights: ► Various obstacles need to be overcome before Boersch phase plates can be used routinely. ► Technical problems include electrostatic charging, mechanical drift, and image artefacts. �

Catalogue of test specimens for non-destructive examination

International Nuclear Information System (INIS)

1985-05-01

One of the key elements in assuring the integrity of reactor primary circuits is the availability of trustworthy non-destructive methods for detecting dangerous defects that may be present. Various approaches to making such examinations are being developed, including the use of ultrasonic and radiographic techniques. To demonstrate their capability and reliability, they must be tested on steel specimens reproducing the various types of faults which may arise in real primary circuit vessels and piping. Such specimens are costly to fabricate. It is therefore clearly desirable that existing specimens should be made accessible to as many organisations as possible for testing. This catalogue contains detailed Information on forty-odd deliberately flawed plates, blocks, vessels, etc. which have been produced in OECD countries, along with the name of a contact person to whom inquiries should be directed in each case

Finite element modeling of penetration of rigid cylindrical bar impacting on a clamped circular plate, employing a strain rate dependent flow rate and a Gruneisen equation of state

International Nuclear Information System (INIS)

Tariq, M.; Khan, I.A.

2003-01-01

A time dependent Finite Element simulation of penetration of a rigid cylindrical bar impacting on a copper plate is conducted, to demonstrate how material behavior appears to change when Johnson-Cook plasticity rule is employed along with a Gruneisen, equation of state with cubic shock velocity-particle relationship, and defining pressure both for compressed and expanded materials, as compared to the behavior when only isotropic strain-hardening model is employed. The bar impacts the plate with a velocity of 1000 m/s, and penetrates the plate, a portion of it coming out of the other side. Results are obtained and compared taking both an isotropic strain-hardening model, and a model incorporating Johnson-Cook flow rule along with Gruneisen equation of state. (author)

Splitting in Dual-Phase 590 high strength steel plates

International Nuclear Information System (INIS)

Yang Min; Chao, Yuh J.; Li Xiaodong; Tan Jinzhu

2008-01-01

Charpy V-notch impact tests on 5.5 mm thick, hot-rolled Dual-Phase 590 (DP590) steel plate were evaluated at temperatures ranging from 90 deg. C to -120 deg. C. Similar tests on 2.0 mm thick DP590 HDGI steel plate were also conducted at room temperature. Splitting or secondary cracks was observed on the fractured surfaces. The mechanisms of the splitting were then investigated. Fracture surfaces were analyzed by optical microscope (OM) and scanning electron microscope (SEM). Composition of the steel plates was determined by electron probe microanalysis (EPMA). Micro Vickers hardness of the steel plates was also surveyed. Results show that splitting occurred on the main fractured surfaces of hot-rolled steel specimens at various testing temperatures. At temperatures above the ductile-brittle-transition-temperature (DBTT), -95 deg. C, where the fracture is predominantly ductile, the length and amount of splitting decreased with increasing temperature. At temperatures lower than the DBTT, where the fracture is predominantly brittle, both the length and width of the splitting are insignificant. Splitting in HDGI steel plates only appeared in specimens of T-L direction. The analysis revealed that splitting in hot-rolled plate is caused by silicate and carbide inclusions while splitting in HDGI plate results from strip microstructure due to its high content of manganese and low content of silicon. The micro Vickers hardness of either the inclusions or the strip microstructures is higher than that of the respective base steel

Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

OpenAIRE

Baumgartner, C; Freydiere, A M; Gille, Y

1996-01-01

Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates w...

Evaluation on Bending Properties of Biomaterial GUM Metal Meshed Plates for Bone Graft Applications

Science.gov (United States)

Suzuki, Hiromichi; He, Jianmei

2017-11-01

There are three bone graft methods for bone defects caused by diseases such as cancer and accident injuries: Autogenous bone grafts, Allografts and Artificial bone grafts. In this study, meshed GUM Metal plates with lower elasticity, high strength and high biocompatibility are introduced to solve the over stiffness & weight problems of ready-used metal implants. Basic mesh shapes are designed and applied to GUM Metal plates using 3D CAD modeling tools. Bending properties of prototype meshed GUM Metal plates are evaluated experimentally and analytically. Meshed plate specimens with 180°, 120° and 60° axis-symmetrical types were fabricated for 3-point bending tests. The pseudo bending elastic moduli of meshed plate specimens obtained from 3-point bending test are ranged from 4.22 GPa to 16.07 GPa, within the elasticity range of natural cortical bones from 2.0 GPa to 30.0 GPa. Analytical approach method is validated by comparison with experimental and analytical results for evaluation on bending property of meshed plates.

Stress corrosion cracking tests on electron beam welded carbon steel specimens in carbonate-bicarbonate solution

International Nuclear Information System (INIS)

Parkins, R.N.

1985-04-01

Stress corrosion cracking tests have been performed on tapered carbon steel test pieces containing electron beam welds with a view to defining susceptibility to such cracking in a carbonate-bicarbonate solution at 90 C and an appropriate electrode potential. The tests involved applying cyclic loads to the specimens and it is shown that the threshold stress for cracking reduces linearly with increase in the magnitude of the cyclic load component. Extrapolation of these trends to zero fluctuating stress indicates static load threshold stresses in the vicinity of the yield stress (i.e. about 300 N/mm 2 for parent plate without a weld, 400 N/mm 2 for specimens with welds on one side only and 600 N/mm 2 for specimens having welds penetrating through the thickness of the specimen). The averages of the maximum crack velocities observed were least for parent plate material and greatest for weld metal, the former being essentially intergranular in morphology and the latter mostly transgranular, with heat affected zone material being intermediate between these extremes. (author)

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Rectangular Gusset Plate Behaviour in Cold-Formed I-Type Steel Connections

Directory of Open Access Journals (Sweden)

Bučmys Ž.

2017-06-01

Full Text Available Cold-formed structure connections utilizing gusset plates are usually semi-rigid. This paper investigates the behaviours of rectangular gusset plates in cold-formed connections of elements whose columns and beams are made with lipped back-to-back C-sections. Methods of calculating strength and stiffness are necessary for such semi-rigid joints. The main task of this paper is to determine a method capable of calculating these characteristics. The proposed analytical method could then be easily adapted to the component method that is described in part 1993-1-8 of the Eurocode. This method allows us to calculate both the strength and stiffness of rectangular gusset plates, assuming that the joint deforms only in plane. This method of design moment resistance calculation was presented taking into account that an entire cross-section shall reach its yield stress. A technique of stiffness calculation was presented investigating the sum of deformations acquired at the bending moment and from shear forces which are transmitted from each beam bolt group. Calculation results according to the suggested method show good agreement of laboratory experimental results of specimens with numerical simulations. Two specimens of beam-to-column connections were tested in the laboratory. Lateral supports were used on the specimens to prevent lateral displacements in order to better investigate the behaviour of the rectangular gusset plate in plane. Experiments were simulated by modelling rectangular gusset plates using standard finite element software ANSYS Workbench 14.0. Three-dimensional solid elements were used for modelling and both geometric and material nonlinear analysis was performed.

Specimen size effect considerations for irradiation studies of SiC/SiC

Energy Technology Data Exchange (ETDEWEB)

Youngblood, G.E.; Henager, C.H. Jr.; Jones, R.H. [Pacific Northwest National Lab., Richland, WA (United States)

1996-10-01

For characterization of the irradiation performance of SiC/SiC, limited available irradiation volume generally dictates that tests be conducted on a small number of relatively small specimens. Flexure testing of two groups of bars with different sizes cut from the same SiC/SiC plate suggested the following lower limits for flexure specimen number and size: Six samples at a minimum for each condition and a minimum bar size of 30 x 6.0 x 2.0 mm{sup 3}.

Impact of implanted metal plates on radiation dose distribution in vivo

International Nuclear Information System (INIS)

Liu Ming; Li Xingde; Niu Qingguo; Zhai Fushan

2010-01-01

Objective: To investigate the impact of metal plate on radiation dose distribution in surrounding tissues in cadaver specimens. Methods: Stainless steel plate, titanium plate, and muscle strip were implanted into the left thigh of a corpse, respectively. All the specimens were irradiated with 6 MV X-ray , SSD = 100 cm. The absorbed dose of surface was measured by thermoluminescent elements. Results: Surface dose distributions differed significantly among the three different materials (F = 57.35, P < 0.01), with the amounts of 1.18 Gy ± 0.04 Gy (stainless steel plate), 1.12 Gy ± 0.04 Gy (titanium plate) and 0.97 Gy ± 0.03 Gy (muscle strip), respectively. The surface absorbed doses on incident plane of stainless steel plate and titanium plate were significantly increased by 21.65% and 15.46% respectively as compared with that of muscle strip. The absorbed doses on the exit surface of stainless steel plate, titanium plate and muscle strip were 0.87 Gy ± 0.03 Gy, 0.90 Gy ± 0.02 Gy and 0.95 Gy ± 0.04 Gy, respectively (F =13.37, P <0.01). The doses on the exit surface of stainless steel plate and titanium plate were significantly lowered by 8.42% and 5.26% when compared with that of muscle strip. Using treatment planning system,the differences between dose distribution with and without metal plate were compared. Within 1 cm away from the incident plate, there was an obvious increase in the absorbed dose, while the influence was less than 5% 1 cm outside the surface. The effect of dose distribution on exit surface was less than 2%. Conclusions: The influence of metal plate on the radiotherapy dose distribution is significant. The deviations ranges from 5% to 29%. Under the same condition, the impact of stainless steel plate is much more than that of titanium alloy plate. (authors)

Experimental Research on Seismic Performance of a New-Type of R/C Beam-Column Joints with End Plates

Directory of Open Access Journals (Sweden)

Shufeng Li

2017-01-01

Full Text Available This paper presents a new-type of fabricated beam-column connections with end plates. The joint details are as follows: the concrete beams are connected to column by end plates and six high strength long bolts passing through the core area. In addition, in order to increase the stiffness and shear strength, stirrups are replaced by the steel plate hoop in the core zone. To examine the fail behavior of the fabricated beam-column connection specimens, a quasi-static test is conducted for nine full-scale models to obtain the hysteresis curves, skeleton curves, ductility, energy dissipation capacity, and other seismic indicators. The experimental results show that all specimens failed in bending in a malleable way with a beam plastic hinge and the hysteresis curves are excellently plump for the end plate connections. From the seismic indexes, the fabricated connection specimens exhibit better seismic performance, which can provide reference for the application of prefabricated frame structure in the earthquake area.

Monolithic integration of nanoscale tensile specimens and MEMS structures

International Nuclear Information System (INIS)

Yilmaz, Mehmet; Kysar, Jeffrey W

2013-01-01

Nanoscale materials often have stochastic material properties due to a random distribution of material defects and an insufficient number of defects to ensure a consistent average mechanical response. Current methods to measure the mechanical properties employ MEMS-based actuators. The nanoscale specimens are typically mounted manually onto the load platform, so the boundary conditions have random variations, complicating the experimental measurement of the intrinsic stochasticity of the material properties. Here we show methods for monolithic integration of a nanoscale specimen co-fabricated with the loading platform. The nanoscale specimen is gold with dimensions of ∼40 nm thickness, 350 ± 50 nm width, and 7 μm length and the loading platform is an interdigitated electrode electrostatic actuator. The experiment is performed in a scanning electron microscope and digital image correlation is employed to measure displacements to determine stress and strain. The ultimate tensile strength of the nanocrystalline nanoscale specimen approaches 1 GPa, consistent with measurements made by other nanometer scale sample characterization methods on other material samples at the nanometer scale, as well as gold samples at the nanometer scale. The batch-compatible microfabrication method can be used to create nominally identical nanoscale specimens and boundary conditions for a broad range of materials. (paper)

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Specimen environments in thermal neutron scattering experiments

International Nuclear Information System (INIS)

Cebula, D.J.

1980-11-01

This report is an attempt to collect into one place outline information concerning the techniques used and basic design of sample environment apparatus employed in neutron scattering experiments. Preliminary recommendations for the specimen environment programme of the SNS are presented. The general conclusion reached is that effort should be devoted towards improving reliability and efficiency of operation of specimen environment apparatus and developing systems which are robust and easy to use, rather than achieving performance at the limits of technology. (author)

Modelling of the Residual Stress State in a new Type of Residual Stress Specimen

DEFF Research Database (Denmark)

Jakobsen, Johnny; Andreasen, Jens Henrik

2014-01-01

forms the experimental case which is analysed. A FE model of the specimen is used for analysing the curing history and the residual stress build up. The model is validated against experimental strain data which are recorded by a Fibre Brag Grating sensor and good agreement has been achieved.......The paper presents a study on a new type residual stress specimen which is proposed as a simple way to conduct experimental validation for model predictions. A specimen comprising of a steel plate with circular hole embedded into a stack of CSM glass fibre and further infused with an epoxy resin...

Analysis of crack opening stresses for center- and edge-crack tension specimens

Directory of Open Access Journals (Sweden)

Tong Di-Hua

2014-04-01

Full Text Available Accurate determination of crack opening stress is of central importance to fatigue crack growth analysis and life prediction based on the crack-closure model. This paper studies the crack opening behavior for center- and edge-crack tension specimens. It is found that the crack opening stress is affected by the crack tip element. By taking the crack tip element into account, a modified crack opening stress equation is given for the center-crack tension specimen. Crack surface displacement equations for an edge crack in a semi-infinite plate under remote uniform tension and partially distributed pressure are derived by using the weight function method. Based on these displacements, a crack opening stress equation for an edge crack in a semi-infinite plate under uniform tension has been developed. The study shows that the crack opening stress is geometry-dependent, and the weight function method provides an effective and reliable tool to deal with such geometry dependence.

Influence of specimen thickness on the fatigue behavior of notched steel plates subjected to laser shock peening

Science.gov (United States)

Granados-Alejo, V.; Rubio-González, C.; Vázquez-Jiménez, C. A.; Banderas, J. A.; Gómez-Rosas, G.

2018-05-01

The influence of specimen thickness on the fatigue crack initiation of 2205 duplex stainless steel notched specimens subjected to laser shock peening (LSP) was investigated. The purpose was to examine the effectiveness of LSP on flat components with different thicknesses. For the LSP treatment a Nd:YAG pulsed laser operating at 10 Hz with 1064 nm of wavelength was used; pulse density was 2500 pulses/cm2. The LSP setup was the waterjet arrangement without sample coating. Residual stress distribution as a function of depth was determined by the hole drilling method. Notched specimens 2, 3 and 4 mm thick were LSP treated on both faces and then fatigue loading was applied with R = 0.1. Experimental fatigue lives were compared with life predictions from finite element simulation. A good comparison of the predicted and experimental fatigue lives was observed. LSP finite element simulation helps in explaining the influence of thickness on fatigue lives in terms of equivalent plastic strain distribution variations associated with the change in thickness. It is demonstrated that specimen size effect is an important issue in applying LSP on real components. Reducing the specimen thickness, the fatigue life improvement induced by LSP is significantly increased. Fatigue life extension up to 300% is observed on thin specimens with LSP.

Fracture toughness and crack growth resistance of pressure vessel plate and weld metal steels

International Nuclear Information System (INIS)

Moskovic, R.

1988-01-01

Compact tension specimens were used to measure the initiation fracture toughness and crack growth resistance of pressure vessel steel plates and submerged arc weld metal. Plate test specimens were manufactured from four different casts of steel comprising: aluminium killed C-Mn-Mo-Cu and C-Mn steel and two silicon killed C-Mn steels. Unionmelt No. 2 weld metal test specimens were extracted from welds of double V butt geometry having either the C-Mn-Mo-Cu steel (three weld joints) or one particular silicon killed C-Mn steel (two weld joints) as parent plate. A multiple specimen test technique was used to obtain crack growth data which were analysed by simple linear regression to determine the crack growth resistance lines and to derive the initiation fracture toughness values for each test temperature. These regression lines were highly scattered with respect to temperature and it was very difficult to determine precisely the temperature dependence of the initiation fracture toughness and crack growth resistance. The data were re-analysed, using a multiple linear regression method, to obtain a relationship between the materials' crack growth resistance and toughness, and the principal independent variables (temperature, crack growth, weld joint code and strain ageing). (author)

Optimization of weld bead geometry of MS plate

Indian Academy of Sciences (India)

The considered specimen was checked to harmonize the optimum setting between input factors, for example, welding current, open circuit voltage, and thickness of plate, with respect to obtaining prosperous weld strength as well as bead geometry quality characteristics, for example, tensile strength, bead width, ...

Coherent x-ray diffraction imaging of paint pigment particles by scanning a phase plate modulator

International Nuclear Information System (INIS)

Chu, Y.S.; Chen, B.; Zhang, F.; Berenguer, F.; Bean, R.; Kewish, C.; Vila-Comamala, J.; Rodenburg, J.; Robinson, I.

2011-01-01

We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

Experimental investigations of sandwich panels using high performance concrete thin plates exposed to fire

DEFF Research Database (Denmark)

Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup

2015-01-01

Structural sandwich panels using thin high performance concrete (HPC) plates offer a possibility to address the modern environmental challenges faced by the construction industry. Fire resistance is a major necessity in structures using HPC. This paper presents experimental studies at elevated...... temperatures for panels with 30 mm thick plates stiffened by structural ribs, thick insulation layers, and steel shear connecting systems. Parametric variation assessing the role of each component of the sandwich structure was performed on unloaded specimens of reduced size. Full size walls were tested...... with load. Tests were performed in standard furnaces, following the conditions of REI certification tests. Unloaded specimens successfully passed tests. Loaded specimens met the R and I requirements, failing E due to sustained flaming of the insulation. They exhibited multiple cracking of their exposed...

Direct identification and recognition of yeast species from clinical material by using albicans ID and CHROMagar Candida plates.

Science.gov (United States)

Baumgartner, C; Freydiere, A M; Gille, Y

1996-02-01

Two chromogenic media, Albicans ID and CHROMagar Candida agar plates, were compared with a reference medium, Sabouraud-chloramphenicol agar, and standard methods for the identification of yeast species. This study involved 951 clinical specimens. The detection rates for the two chromogenic media for polymicrobial specimens were 20% higher than that for the Sabouraud-chloramphenicol agar plates. The rates of identification of Candida albicans for Albicans ID and CHROMagar Candida agar plates were, respectively, 37.0 and 6.0% after 24 h of incubation and 93.6 and 92.2% after 72 h of incubation, with specificities of 99.8 and 100%. Furthermore, CHROMagar Candida plates identified 13 of 14 Candida tropicalis and 9 of 12 Candida krusei strains after 48 h of incubation.

Flaw behavior in mechanically loaded clad plates

International Nuclear Information System (INIS)

Iskander, S.K.; Robinson, G.C.; Oland, C.B.

1989-01-01

A small crack near the inner surface of clad nuclear reactor pressure vessels is an important consideration in the safety assessment of the structural integrity of the vessel. Four-point bend tests on large plate specimens, conforming to ASTM specification for pressure vessel plates, alloy steels, quenched and tempered, Mn-Mo and Mn-Mo-Ni (A533) grade B six clad and two unclad with stainless steels 308, 309 and 312 weld wires, were performed to determine the effect of cladding upon the propagation of small surface cracks subjected to stress states. Results indicated that the tough surface layer composed of cladding and/or heat-affected zone has enhanced the load-bearing capacity of plates under conditions where unclad plates have ruptured. The results are interpreted in terms of fracture mechanics. The behavior of flaws in clad reactor pressure vessels is examined in the light of the test results. 11 refs., 8 figs., 2 tabs

Results from low cycle fatigue testing of 316L plate and weld material

International Nuclear Information System (INIS)

Kaellstroem, R.; Josefsson, B.; Haag, Y.

1993-01-01

Specimens for low cycle fatigue testing from the second heat of the CEC reference 316L plate and from Tungsten Inert Gas (TIG) weld material have been neutron irradiated near room temperature to a displacement dose of approximately 0.3 dpa. The low cycle fatigue testing of both irradiated and unirradiated specimens was performed at 75, 250 and 450 degrees C, and with strain ranges of 0.75, 1.0 and 1.5%. There is no clear effect of the irradiation on low cycle fatigue properties. For the weld material the endurance is shorter than for plate, and the dependences on temperature and strain range are not clear

Fabrication of mandible fracture plate by indirect additive manufacturing

Science.gov (United States)

Aizat, M.; Khan, S. F.

2017-10-01

Bone fracture is a serious skeletal injury due to accidents and fragility of the bones at a certain age. In order to accelerate fracture healing process, fracture bone plate is use to hold the fracture segment for more stability. The purpose of this study is to fabricate mandibular fracture plate by using indirect additive manufacturing methods in order to reduce time taken during bending and shaping the fracture fixation plate that conform to the anatomy of the fractured bone site. The design and analysis of the plates are performed using CATIA and ANSYS software. The 3D-CAD data were sent to an additive manufacturing machine (fused filament fabricated) to generate master pattern using PLA and the mould were fabricated using Plaster of Paris. A melt ZAMAK 3 was poured directly into the moulds, and left it until completely harden. 3point bending test was performed on the prototype plate using universal testing machine. Stress-strain curve shows the graph exhibited a linear relationship of stress-strain up to a strain value of 0.001. Specimens give a maximum yielding stress and then break before the conventional deflection. Since the maximum flexural stress and the breaking stress are far apart with a plateau stating at strain value of 0.003mm/mm in most specimens, the specimen’s failure types are considered plastic failure mode. The average thickness and width are 1.65mm and 2.18mm respectively. The flexural modulus and flexural strength are 189.5GPa and 518.1MPa, respectively.

Neutron radiography using neutron imaging plate

International Nuclear Information System (INIS)

Chankow, Nares; Wonglee, Sarinrat

2008-01-01

Full text: The aims of this research are to study properties of neutron imaging plate, to obtain a suitable condition for neutron radiography and to use the neutron imaging plate for testing of materials nondestructively. The experiments were carried out by using a neutron beam from the Thai Research Reactor TRR-1/M1 at a power of 1.2 MW. A BAS-ND 2040 FUJI neutron imaging plate and a MX125 Kodak X-ray film/Gadolinium neutron converter screen combination were tested for comparison. It was found that the photostimulated light (PSL) read out of the imaging plate was directly proportional to the exposure time. It was also found that radiography with neutron using the imaging plate was approximately 40 times faster than the conventional neutron radiography using x-ray film/Gd converter screen combination. The sensitivity of the imaging plate to gamma-rays was investigated by using gamma-rays from an 192 Ir and a 60 Co radiographic sources. The imaging plate was found to be 5-6 times less sensitive to gamma-rays than a FUJI BAS-MS 2040 gamma-ray imaging plate. Finally, some specimens were selected to be radiographed with neutrons using the imaging plate and the x-ray film/Gd converter screen combination in comparison to x-rays. Parts containing light elements could be clearly observed by the two neutron radiographic techniques. It could be concluded that the image quality from the neutron imaging plate was comparable to the conventional x-ray film/Gd converter screen combination but the exposure time could be approximately reduced by a factor of 40

Experimental study on behavior of RC panels covered with steel plates subjected to missile impact

International Nuclear Information System (INIS)

Jun Hashimoto; Katsuki Takiguchi; Koshiro Nishimura; Kazuyuki Matsuzawa; Mayuko Tsutsui; Yasuhiro Ohashi; Isao Kojima; Haruhiko Torita

2005-01-01

This paper describes an experimental study on the behavior of concrete panels with steel plate subjected to missile impact. Two tests were carried out, divided in accordance with the types of projectile, non-deformable and deformable. In all, 40 specimens of 750 mm square were prepared. The panel specimen was suspended vertically by two steel wire ropes to allow free movement after projectile impact, and was subjected to a projectile. As a result, it is confirmed that a RC panel with steel plate on its back side has higher impact resistance performance than a RC panel and that thickness of concrete panel, thickness of steel plate and the impact velocity of the projectile have a great effect on the failure modes of steel concrete panels. Moreover, based on the experimental results, the quantitative evaluation method for impact resistance performance of RC panels covered with steel plates is examined. The formula for perforation velocity of a half steel concrete panel, proposed in accordance with the bulging height, is effective to evaluate the impact resistance performance of RC panels with steel plates. (authors)

Elevated-temperature tests of simply-supported beams and circular plates subjected to time-varying loadings

International Nuclear Information System (INIS)

Corum, J.M.; Richardson, M.

1975-01-01

The measured elastic-plastic and elastic-plastic-creep responses of a number of simply-supported type 304 stainless steel beams and circular plates are presented. Beams and plates exhibit the essential features of inelastic structural behavior; yet they are relatively simple. In beams, the stress fields are largely uniaxial, while multiaxial effects are introduced in plates. The specimens were laterally loaded at the center, and the tests were performed by subjecting the specimens to either a prescribed load or center-deflection history. The specimens were machined from a common, well-characterized heat of material, and all of the tests were performed at a temperature of 1100 F. The elastic-plastic tests consisted of short-time cycling of the center load, or deflection, between fixed limits. In the elastic-plastic-creep tests the center load, or deflection, was held constant for periods of time, but was periodically subjected to a step increase or decrease, including reversals. The test results are presented in terms of the load and center-deflection behaviors, which typify the overall structural behavior. (U.S.)

Comparison of the results of wide plate tests with the predictions of several fracture concepts

International Nuclear Information System (INIS)

Rosezin, H.J.; Dahl, W.

1985-01-01

With the results of wide plate tests on center cracked specimens the concept of the plastic limit load, the Burdekin-Dawes-design-concept, the J-design-curve according to Turner, the estimation proceeding according to Shih and Kumar, the Two-Criteria-Approach and the FAD according to Pellini were examined and the limits of their application exhibited. The maximum loads of wide plate specimens can be estimated by the plastic limit load, if no low-stress-fractures occur. Corresponding to the Pellini-concept no low-stress-fractures occured at test temperatures above NDT, if the NDT-temperature of the region of material was used, in which the crack was located. With the concept according to Shih and Kumar an estimation of the instability loads of wide plate specimens is possible, if the fracture behaviour is fully ductile, but not in all cases conservative predictions were made. A prediction of critical stresses and crack sizes is possible with the other concepts examined, if the evaluations are based on the critical values for the onset of stable or unstable crack growth. (orig.) [de

Residual stress investigation of copper plate and canister EB-Welds Complementary Results

International Nuclear Information System (INIS)

Gripenberg, H.

2009-03-01

The residual stresses in copper as induced by EB-welding were studied by specimens where the weld had two configurations: either a linear or a circumferential weld. This report contains the residual stress measurements of two plates, containing linear welds, and the full-scale copper lid specimen to which a hollow cylinder section had been joined by a circumferential EB-weld. The residual stress state of the EB-welded copper specimens was investigated by X-ray diffraction (XRD), hole drilling (HD) ring core (RC) and contour method (CM). Three specimens, canister XK010 and plates X251 and X252, were subjected to a thorough study aiming at quantitative determination of the residual stress state in and around the EB-welds using XRD for surface and HD and RC for spatial stress analysis. The CM maps one stress component over a whole cross section. The surface residual stresses measured by XRD represent the machined condition of the copper material. The XRD study showed that the stress changes towards compression close to the weld in the hollow cylinder, which indicates shrinkage in the hoop direction. According to the same analogy, the shrinkage in the axial direction is much smaller. The HD measurements showed that the stress state in the base material is bi-axial and, in terms of von Mises stress, 50 MPa for the plates and 20 MPa for the cylinder part of the canister. The stress state in the EB-welds of all specimens differs clearly from the stress state in the base material being more tensile, with higher magnitudes of von Mises stress in the plate than in the canister welds. The HD and RC results were obtained using linear elastic theory. The RC measurements showed that the maximum principal stress in the BM is close to zero near the surface and it becomes slightly tensile, 10 MPa, deeper under the surface. Welding pushed the general stress state towards tension with the maximum principal stress reaching 50 MPa, deeper than 5 mm below the surface in the weld. The

Thinning of specimens for examination under the electron microscope

International Nuclear Information System (INIS)

Franks, J.

1982-01-01

Heretofore specimens have been thinned to penetration for examination by electron microscopy techniques, by ion erosion techniques. A more rapid technique is disclosed employing a beam or beams comprised solely of neutral particles. In tests carried out using this technique the sputtering rate from a sample specimen has been shown to be several percentages greater using a neutral source than from an ion source with the same flux density. (author)

Electrospark Deposition for Depot- and Field-Level Component Repair and Replacement of Hard Chromium Plating

Science.gov (United States)

2006-09-07

ducted away and removed by scrubbers . Wastes generated from plating operations must be disposed of as hazardous waste and plating operations must...specimens were austentized at 1875o F, held for approximately 45 minutes, quenched in dissociated ammonia to approximately 150o F, and tempered for two...Lab analysis labor no change Estimated based on previous plating CBAs Scrubber maintenance captured elsewhere Captured in total scrubber costs

Estimation of residual stresses in reactor pressure vessel steel specimens clad by stainless steel strip electrodes

International Nuclear Information System (INIS)

Schimmoeller, H.A.; Ruge, J.L.

1978-01-01

The equations to determine a two-dimensional state of residual stress in flat laminated plates are well known from an earlier work by one of the authors. The derivation of these equations leads to a linear, inhomogeneous system of Volterra's integral equations of the second kind. To ascertain the unknown residual stresses from these equations it is necessary to cut down the thickness of the test plate layer by layer. This results in two-dimensional deformation reactions in the rest of the test plate, which can be measured, e.g. by a strain gauge rosette applied to the opposite side of the plate. The above-mentioned stress analysis has been transferred to 86mm thick reactor pressure vessel steel specimens (Type 22NiMoCr 37, DIN-No. 1.6751, similar to ASTM A508, Class 2) double-run clad by austenitic stainless steel strip electrodes (first layer 24/13 Cr-Ni steel, second layer 21/10 Cr-Ni steel). The overall dimensions of the clad specimens investigated amounted to 200 x 200 x (86+4.5+4.5)mm. At the surface of the austenitic cladding there is a two-dimensional tensile normal stress state of about 200N/mm 2 parallel, and about 300N/mm 2 transverse, to the welding direction. The maximum tensile stress was 8mm below the interface (fusion line, material transition) in the parent material. The stress distributions of the specimens investigated, determined on the basis of the above-mentioned combined experimental mathematical procedure, are presented graphically for the as-welded (as-delivered) and annealed (600 0 C/12hr) conditions. (author)

Some aspects of thick, soft nickel plating for end shields of atomic power plants

International Nuclear Information System (INIS)

Krishnaswamy, R.

1987-01-01

Thick (55 Thou) and soft (160 vickers) hardness number nickel plating over SS for RAPP end shields presented unusual problems as the thickness required was extremely large creating adhesion problems and the extremely stringent hardness conditions. A sulfamate bath with nickel anode was found suitable. The problems in thick, soft plating, the chemical and other procedures adopted to monitor the bath and the plated specimen and the other details are presented. (author). 11 refs

Blast response of corroded steel plates

Energy Technology Data Exchange (ETDEWEB)

Eslamimajd, Alireza; RahbarRanji, Ahmad [AmirKabir University of Technology, Tehran (Korea, Republic of)

2014-05-15

Numerical results for one- and both-sided corroded steel plates subjected to blast loading are presented. Finite element analysis, with ABAQUS software, is employed to determine the deformation and stress distributions. The results for the case of triangular pulse pressure on un-corroded plates are validated against literature-based data and then, detailed parametric studies are carried-out. The effects of influential parameters including, plate aspect ratio, degree of pit and different ratio of pit depth at each sides of the plate are investigated. The results show that position of pitted surface in respect to applied pressure is the most influential parameter on reduction of dynamic load carrying capacity of pitted plates. By increasing degree of pitting, reduction of dynamic load carrying capacity decrease more.

White Light Photorefractive Phase Zone Plates

International Nuclear Information System (INIS)

Yuan-Mei, Gao; Si-Min, Liu

2008-01-01

Incoherent white light from an incandescent source is employed to fabricate volume phase zone plates in LiNbO 3 : Fe, for the first time to our knowledge, which can guide and modulate the input white light or laser light. The diffractive efficiency of the white light volume phase zone plates fabricated can reach as high as 12%. In addition, we test the volume phase zone plates by a probe beam and find that the volume phase zone plate is present in the direction perpendicular to the c-axis and absent in the direction parallel to the c-axis. This directly proves the existence of photovoltaic photorefractive anisotropy of white light

The response of pressure vessel steel specimens on drop weight loading

International Nuclear Information System (INIS)

Winkler, S.; Kalthoff, J.F.; Gerscha, A.

1979-01-01

Load records obtained in instrumented impact tests in general are disturbed by inertia effects. The influence of mechanical damping provisions on these disturbing inertia effects is investigated. Precracked bend specimens are dynamically loaded in a drop weight testing system. The specimens of size 620 mm x 150 mm (25 mm or 50 mm thick) were machined from the pressure vessel steel 22 NiMoCr 37 which was heat treated to achieve a specially hardened condition. The tests were performed at two different low temperatures. The impact velocity was about 4 m/s. As it is usual in instrumented impact testing, the load at the tup of the impining striker is recorded as a function of time during the impact process. In addition the specimen is instrumented by a strain gage close to the crack tip in order to directly measure the stress intensification. Experiments were performed under pure and damped impact conditions. Damping was achieved by utilizing a soft aluminum plate between the striker and the specimen. (orig.)

Hard X-ray phase-contrast microscope for observing transparent specimens

Energy Technology Data Exchange (ETDEWEB)

Kagoshima, Y.; Yokoyama, Y.; Niimi, T.; Koyama, T.; Tsusaka, Y.; Matsui, J. [Himeji Institute of Technology, Graduate School of Science, Hyogo (Japan); Takai, K. [Japan synchrotron Radiation Research Institute, Mikazuki, Hyogo (Japan)

2002-08-01

A hard X-ray transmission imaging microscope has been in use at the beamline BL24XU of Spring-8. It makes use of a phase zone plate made of tantalum as its X-ray lens, and is capable of imaging the structure as fine as 125-nm line-and-space pattern. The Zernike's phase-contrast method has been implemented to the microscope with phase plates made of gold. The photon energy was tuned to 12 keV just above the L{sub 3} absorption edge of gold (11.9 keV) in order to increase the image contrast. Polystyrene micro particles as transparent specimens were imaged clearly in the opposite image contrast with phase plates to shift the phase of the central order spectra in the back focal plane of the objective by one-quarter and three-quarters of a period, while the absorption contrast image showed little image contrast. Performance of the newly developed phase zone plate has been tested and it was confirmed that the structure as fine as 60-mm line-and-space pattern was able to be imaged. (authors)

Method for regeneration of electroless nickel plating solution

Science.gov (United States)

Eisenmann, E.T.

1997-03-11

An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorus acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution. 1 fig.

Method for regeneration of electroless nickel plating solution

Science.gov (United States)

Eisenmann, Erhard T.

1997-01-01

An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorous acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution.

Damage characterization and modeling of a 7075-T651 aluminum plate

International Nuclear Information System (INIS)

Jordon, J.B.; Horstemeyer, M.F.; Solanki, K.; Bernard, J.D.; Berry, J.T.; Williams, T.N.

2009-01-01

In this paper, the damage-induced anisotropy arising from material microstructure heterogeneities at two different length scales was characterized and modeled for a wrought aluminum alloy. Experiments were performed on a 7075-T651 aluminum alloy plate using sub-standard tensile specimens in three different orientations with respect to the rolling direction. Scanning electron microscopy was employed to characterize the stereology of the final damage state in terms of cracked and or debonded particles. A physically motivated internal state variable continuum model was used to predict fracture by incorporating material microstructural features. The continuum model showed good comparisons to the experimental data by capturing the damage-induced anisotropic material response. Estimations of the mechanical stress-strain response, material damage histories, and final failure were numerically calculated and experimentally validated thus demonstrating that the final failure state was strongly dependent on the constituent particle morphology.

Stability of midface fracture repair using absorbable plate and screw system pilot holes drilled and pin placement at angles other than 90°.

Science.gov (United States)

Carron, Michael A; Zuliani, Giancarlo; Pereira, Lucio; Abuhamdan, Maher; Thibault, Adrianna; Dau, Nathan; Bir, Cynthia

2014-01-01

Conventional plating systems use titanium plates for fixation of fractures, with benefits of strength and biocompatibility. However, titanium plates require that screws be placed at a 90° angle to the pilot holes. In the midface, this becomes extremely difficult. Today, a variety of craniomaxillofacial osteosynthesis systems are available, including resorbable plating systems. Specifically, the KLS Martin Sonic Weld system ultrasonically fuses the plate and the head of the pin when placed and will fill the pilot hole grooves completely even at less than 90° angles, which provides a tremendous advantage in midface fracture repair. To determine if the KLS Martin Sonic Weld system provides plate-screw construct stability in human heads even when placed at acute angles at the midface buttresses. DESIGN, SETTING, AND SPECIMENS: Twenty cadaveric head specimens with the mandible removed were prepared by creating osteotomies in the midface buttresses bilaterally. Specimens were defleshed and placed in a 2-part testing rig to hold and position the head for testing in a standard material testing system. Testing was performed at the Wayne State University Bioengineering test laboratories, Detroit, Michigan, using an Instron device and high-speed camera. Specimens were plated on one side of the midface using the KLS Martin Sonic Weld system with pilot holes and pins placed at 90° angles. On the contralateral side, the buttresses were plated with the KLS Martin Sonic Weld system at 60°, 45°, and 30° angles. Data were collected using the TDAS data acquisition system and were compared with matched pairs within each specimen. Ultrasonically vibrated pins placed into absorbable mini-plates at less than 90° angles with the KLS Martin Sonic Weld system were compared with the same amount of stress as the system placed at a 90° angle before demonstrating plate-screw construct failure. RESULTS Fifty-seven paired tests were collected, with 114 total tests. Twenty failures were

Fundamental Study of Electron Beam Welding of AA6061-T6 Aluminum Alloy for Nuclear Fuel Plate Assembly (II)

International Nuclear Information System (INIS)

Kim, Soosung; Lee, Haein; Lee, Donbae; Park, Jongman; Lee, Yoonsang

2013-01-01

Certain characteristics, such as solidification cracking, porosity, HAZ (Heat-affected Zone) degradation must be considered during welding. Because of high energy density and low heat input, especially LBW and EBW processes posses the advantage of minimizing the fusing zone and HAZ and producing deeper penetration than arc welding processes. In present study, to apply for the nuclear fuel plate fabrication and assembly, a fundamental EBW experiment using AA6061-T6 aluminum alloy specimens was conducted. Furthermore, to establish the welding process, and satisfy the requirements of the weld quality, EBW apparatus using a electron welding gun and vacuum chamber was developed, and preliminary investigations for optimizing the welding parameters of the specimens using AA6061-T6 aluminum plates were also performed. In this experiment, a feasibility test was carried out by tensile tester, bead-on-plate welding and metallographic examination to comply with the aluminum welding procedure. The EB weld quality of AA6061-T6 aluminum alloy for the fuel plate assembly has been also studied by the mechanical testing and microstructure examinations. This study was carried out to determine the suitable welding process and to investigate tensile strength of AA6061-T6 aluminum alloy. In the present experiment, satisfactory EBW of the square butt weld specimens was developed. In comparison with the rolling directions of test specimens, the tensile strengths were no difference between the longitudinal and transverse welds. Based on this fundamental study, fabrication and assembly of the nuclear fuel plates will be provided for the future Kijang research reactor project

Experimental and Numerical Evaluation of Direct Tension Test for Cylindrical Concrete Specimens

Directory of Open Access Journals (Sweden)

Jung J. Kim

2014-01-01

Full Text Available Concrete cracking strength can be defined as the tensile strength of concrete subjected to pure tension stress. However, as it is difficult to apply direct tension load to concrete specimens, concrete cracking is usually quantified by the modulus of rupture for flexural members. In this study, a new direct tension test setup for cylindrical specimens (101.6 mm in diameter and 203.2 mm in height similar to those used in compression test is developed. Double steel plates are used to obtain uniform stress distributions. Finite element analysis for the proposed test setup is conducted. The uniformity of the stress distribution along the cylindrical specimen is examined and compared with rectangular cross section. Fuzzy image pattern recognition method is used to assess stress uniformity along the specimen. Moreover, the probability of cracking at different locations along the specimen is evaluated using probabilistic finite element analysis. The experimental and numerical results of the cracking location showed that gravity effect on fresh concrete during setting time might affect the distribution of concrete cracking strength along the height of the structural elements.

Standard practice for preparation and use of Bent-Beam stress-corrosion test specimens

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This practice covers procedures for designing, preparing, and using bent-beam stress-corrosion specimens. 1.2 Different specimen configurations are given for use with different product forms, such as sheet or plate. This practice applicable to specimens of any metal that are stressed to levels less than the elastic limit of the material, and therefore, the applied stress can be accurately calculated or measured (see Note 1). Stress calculations by this practice are not applicable to plastically stressed specimens. Note 1—It is the nature of these practices that only the applied stress can be calculated. Since stress-corrosion cracking is a function of the total stress, for critical applications and proper interpretation of results, the residual stress (before applying external stress) or the total elastic stress (after applying external stress) should be determined by appropriate nondestructive methods, such as X-ray diffraction (1). 1.3 Test procedures are given for stress-corrosion testing by ex...

Experimental Studies on the Fire Behaviour of High Performance Concrete Thin Plates

DEFF Research Database (Denmark)

Hulin, Thomas; Hodicky, Kamil; Schmidt, Jacob Wittrup

2015-01-01

In recent decades, the use of structural high performance concrete (HPC) sandwich panels made with thin plates has increased as a response to modern environmental challenges. Fire endurance is a requirement in structural HPC elements, as for most structural elements. This paper presents experimen......In recent decades, the use of structural high performance concrete (HPC) sandwich panels made with thin plates has increased as a response to modern environmental challenges. Fire endurance is a requirement in structural HPC elements, as for most structural elements. This paper presents....... The parametric assessment of the specimen performance included: thickness of the specimen, testing apparatus, and concrete mix (both with and without polypropylene fibres). The results verified the ability of H-TRIS to impose an equivalent thermal boundary condition to that imposed during a standard furnace test......, with good repeatability, and at comparatively low economic and temporal costs. The results demonstrated that heat induced concrete spalling occurred 1 to 5 min earlier, and in a more destructive manner, for thinner specimens. An analysis is presented combining the thermal material degradation, vapour pore...

Experimental Study on Temperature Behavior of SSC (Stiffened Steel Plate Concrete) Structures

International Nuclear Information System (INIS)

Lee, K. J.; Ham, K. W.; Park, D. S.; Kwon, K. J.

2008-01-01

SSC(Stiffened Steel plate Concrete) module method uses steel plate instead of reinforcing bar and mold in existing RC structure. Steel plate modules are fabricated in advance, installed and poured with concrete in construction field, so construction period is remarkably shortened by SC module technique. In case of existence of temperature gap between internal and external structure surface such as containment building, thermal stress is taken place and as a result of it, structural strength is deteriorated. In this study, we designed two test specimens and several tests with temperature heating were conducted to evaluate temperature behavior of SSC structures and RC structure

Corrosion behavior, mechanical properties, and long-term aging of nickel-plated uranium

International Nuclear Information System (INIS)

Dini, J.W.; Johnson, H.R.; Schoenfelder, C.W.

1976-01-01

The behavior of nickel-plated uranium upon exposure to moist nitrogen was evaluated. Plating thicknesses of 0.051 mm (2 mil) were adequate to prevent corrosion. Specimens with thinner coats showed some corrosion and some reduction in mechanical properties during subsequent testing. Plated samples exposed to dry air at ambient pressure for 10 y showed no corrosion and no degradation of mechanical properties. Surface and bulk hydrogen content, as well as free hydrogen generated during the test, were measured to determine the extent of corrosion. Results support an earlier proposed mechanism for uranium corrosion at low humidities

In-focus electron microscopy of frozen-hydrated biological samples with a Boersch phase plate

Energy Technology Data Exchange (ETDEWEB)

Barton, B.; Rhinow, D.; Walter, A.; Schroeder, R. [Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main (Germany); Benner, G.; Majorovits, E.; Matijevic, M.; Niebel, H. [Carl Zeiss NTS GmbH, D-73447 Oberkochen (Germany); Mueller, H.; Haider, M. [CEOS GmbH, Englerstr. 26, 69126 Heidleberg (Germany); Lacher, M.; Schmitz, S.; Holik, P. [Caesar Research Center, Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany); Kuehlbrandt, W., E-mail: werner.kuehlbrandt@mpibp-frankfurt.mpg.de [Max Planck Institute of Biophysics, Max-von-Laue Str. 3, 60438 Frankfurt am Main (Germany)

2011-12-15

We report the implementation of an electrostatic Einzel lens (Boersch) phase plate in a prototype transmission electron microscope dedicated to aberration-corrected cryo-EM. The combination of phase plate, C{sub s} corrector and Diffraction Magnification Unit (DMU) as a new electron-optical element ensures minimal information loss due to obstruction by the phase plate and enables in-focus phase contrast imaging of large macromolecular assemblies. As no defocussing is necessary and the spherical aberration is corrected, maximal, non-oscillating phase contrast transfer can be achieved up to the information limit of the instrument. A microchip produced by a scalable micro-fabrication process has 10 phase plates, which are positioned in a conjugate, magnified diffraction plane generated by the DMU. Phase plates remained fully functional for weeks or months. The large distance between phase plate and the cryo sample permits the use of an effective anti-contaminator, resulting in ice contamination rates of <0.6 nm/h at the specimen. Maximal in-focus phase contrast was obtained by applying voltages between 80 and 700 mV to the phase plate electrode. The phase plate allows for in-focus imaging of biological objects with a signal-to-noise of 5-10 at a resolution of 2-3 nm, as demonstrated for frozen-hydrated virus particles and purple membrane at liquid-nitrogen temperature. -- Highlights: Black-Right-Pointing-Pointer We implement an electrostatic Boersch phase plate into a dedicated prototypical TEM. Black-Right-Pointing-Pointer Phase contrast aberration-corrected electron microscope (PACEM) includes a diffraction magnification unit (DMU). Black-Right-Pointing-Pointer DMU minimizes obstruction of low spatial frequencies by the phase plate. Black-Right-Pointing-Pointer In-focus phase contrast generation is demonstrated for frozen-hydrated biological specimens.

Improving visibility of rear surface cracks during inductive thermography of metal plates using Autoencoder

Science.gov (United States)

Xie, Jing; Xu, Changhang; Chen, Guoming; Huang, Weiping

2018-06-01

Inductive thermography is one kind of infrared thermography (IRT) technique, which is effective in detection of front surface cracks in metal plates. However, rear surface cracks are usually missed due to their weak indications during inductive thermography. Here we propose a novel approach (AET: AE Thermography) to improve the visibility of rear surface cracks during inductive thermography by employing the Autoencoder (AE) algorithm, which is an important block to construct deep learning architectures. We construct an integrated framework for processing the raw inspection data of inductive thermography using the AE algorithm. Through this framework, underlying features of rear surface cracks are efficiently extracted and new clearer images are constructed. Experiments of inductive thermography were conducted on steel specimens to verify the efficacy of the proposed approach. We visually compare the raw thermograms, the empirical orthogonal functions (EOFs) of the prominent component thermography (PCT) technique and the results of AET. We further quantitatively evaluated AET by calculating crack contrast and signal-to-noise ratio (SNR). The results demonstrate that the proposed AET approach can remarkably improve the visibility of rear surface cracks and then improve the capability of inductive thermography in detecting rear surface cracks in metal plates.

direct method of analysis of an isotropic rectangular plate direct

African Journals Online (AJOL)

eobe

This work evaluates the static analysis of an isotropic rectangular plate with various the static analysis ... method according to Ritz is used to obtain the total potential energy of the plate by employing the used to ..... for rectangular plates analysis, as the behavior of the ... results obtained by previous research work that used.

Ductile fracture toughness of heavy section pressure vessel steel plate. A specimen-size study of ASTM A 533 steels

International Nuclear Information System (INIS)

Williams, J.A.

1979-09-01

The ductile fracture toughness, J/sub Ic/, of ASTM A 533, Grade B, Class 1 and ASTM A 533, heat treated to simulate irradiation, was determined for 10- to 100-mm thick compact specimens. The toughness at maximum specimen load was also measured to determine the conservatism of J/sub Ic/. The toughness of ASTM A 533, Grade B, Class 1 steel was 349 kJ/m 2 and at the equivalent upper shelf temperature, the heat treated material exhibited 87 kJ/m 2 . The maximum load fracture toughness was found to be linearly proportional to specimen size, and only specimens which failed to meet ASTM size criteria exhibited maximum load toughness less than J/sub Ic/

Optimization of geometrical characteristics of perforated plates

International Nuclear Information System (INIS)

Radisavljevic, Igor; Balos, Sebastian; Nikacevic, Milutin; Sidjanin, Leposava

2013-01-01

Highlights: ► Perforated plate are tested against 12.7 mm API projectile. ► Perforations similar to the projectile diameter offer more efficient core fracture. ► Larger perforations gave a more efficient core fragmentation. ► SEM microscopy analysis has shown a ductile fracture mode at impact point. - Abstract: In this paper, an attempt was made to design effective non-homogenous armor in form of perforated plate mounted at close distance from basic armor plate. Perforated plate with three perforation diameters: 9, 10 and 11 mm, two ligaments length: 3.5 and 4.5 mm ligaments, set at 0° and 28° angles, were combined to 13 mm basic plate and tested against 12.7 mm API ammunition. It has been shown that larger perforations gave a more efficient core fragmentation, while angled specimens were the only ones that offer full protection against five API shots when the perforated plate was placed at 100 mm from the basic plate. Perforations that are similar in size to the penetrating core diameter offer a more efficient core fracture, leading to a faster fragment separation. This may enable a smaller distance between the add-on perforated and basic plate to be used. Scanning electron microscopy analysis has shown a ductile fracture mode at impact point, with hardness values on plate basic level. On the other hand, a brittle fracture mode with a rise in local hardness measured near impact point is a result of intensive high speed plastic deformation produced by bending stresses. A drop in local hardness measured near impact point, may be the result of intensive cracking that occur due to repeated projectile impact

Steel plates and concrete filled composite shear walls related nuclear structural engineering: Experimental study for out-of-plane cyclic loading

International Nuclear Information System (INIS)

Li, Xiaohu; Li, Xiaojun

2017-01-01

Based on the program of CAP1400 nuclear structural engineering, the out-of-plane seismic behavior of steel plate and concrete infill composite shear walls (SCW) was investigated. 6 1/5 scaled specimens were conducted which consist of 5 SCW specimens and 1 reinforced concrete (RC) specimen. The specimens were tested under out-of-plane cyclic loading. The effect of the thickness of steel plate, vertical load and the strength grade of concrete on the out-of-plane seismic behavior of SCW were analyzed. The results show that the thickness of steel plate and vertical load have great influence on the ultimate bearing capacity and lateral stiffness, however, the influence of the strength grade of concrete was little within a certain range. SCW is presented to have a better ultimate capacity and lateral stiffness but have worse ductility in failure stage than that of RC. Based on the experiment, the cracking load of concrete infill SCW was analyzed in theory. The modified calculation formula of the cracking load was made, the calculated results showed good agreement with the test results. The formula can be used as the practical design for the design of cracking loads.

Steel plates and concrete filled composite shear walls related nuclear structural engineering: Experimental study for out-of-plane cyclic loading

Energy Technology Data Exchange (ETDEWEB)

Li, Xiaohu [The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124 (China); Li, Xiaojun, E-mail: beerli@vip.sina.com [The College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124 (China); Institute of Geophysics, China Earthquake Administration, Beijing 100081 (China)

2017-04-15

Based on the program of CAP1400 nuclear structural engineering, the out-of-plane seismic behavior of steel plate and concrete infill composite shear walls (SCW) was investigated. 6 1/5 scaled specimens were conducted which consist of 5 SCW specimens and 1 reinforced concrete (RC) specimen. The specimens were tested under out-of-plane cyclic loading. The effect of the thickness of steel plate, vertical load and the strength grade of concrete on the out-of-plane seismic behavior of SCW were analyzed. The results show that the thickness of steel plate and vertical load have great influence on the ultimate bearing capacity and lateral stiffness, however, the influence of the strength grade of concrete was little within a certain range. SCW is presented to have a better ultimate capacity and lateral stiffness but have worse ductility in failure stage than that of RC. Based on the experiment, the cracking load of concrete infill SCW was analyzed in theory. The modified calculation formula of the cracking load was made, the calculated results showed good agreement with the test results. The formula can be used as the practical design for the design of cracking loads.

Residual stress state in pipe cut ring specimens for fracture toughness testing

Energy Technology Data Exchange (ETDEWEB)

Damjanovic, Darko [J.J. Strossmayer Univ. of Osijek, Slavonski Brod (Croatia). Mechanical Engineering Faculty; Kozak, Drazan [Zagreb Univ. (Croatia). Dept. for Mechanical Design; Marsoner, Stefan [Materials Center, Leoben (Austria).; Gubeljak, Nenad [Maribor Univ. (Slovenia). Chair of Mechanics

2017-07-01

Thin-walled pipes are not suitable for measuring fracture toughness parameters of vital importance because longitudinal crack failure is the most common failure mode in pipes. This is due to the impossibility to manufacture standard specimens for measuring fracture toughness, such as SENB or CT specimens, from the thin wall of the pipe. Previous works noticed this problem, but until now, a good and convenient solution has not been found or developed. To overcome this problem, very good alternative solution was proposed, the so-called pipe ring notched bend specimen (PRNB) [1-5]. Until now, only the idealized geometry PRNB specimen is analyzed, i. e., a specimen which is not cut out from an actual pipe but produced from steel plate. Based on that, residual stresses are neglected along with the imperfections in geometry (elliptical and eccentricity). The aim of this research is to estimate the residual stress state(s) in real pipes used in the boiler industry produced by hot rolling technique. These types of pipes are delivered only in normalized condition, but not stress relieved. Therefore, there are residual stresses present due to the manufacturing technique, but also due to uneven cooling after the production process. Within this paper, residual stresses are estimated by three methods: the incremental hole drilling method (IHMD), X-ray diffraction (XRD) and the splitting method (SM). Knowing the residual stress state in the ring specimen, it is possible to assess their impact on fracture toughness measured on the corresponding PRNB specimen(s).

Residual stress state in pipe cut ring specimens for fracture toughness testing

International Nuclear Information System (INIS)

Damjanovic, Darko; Kozak, Drazan; Marsoner, Stefan; Gubeljak, Nenad

2017-01-01

Thin-walled pipes are not suitable for measuring fracture toughness parameters of vital importance because longitudinal crack failure is the most common failure mode in pipes. This is due to the impossibility to manufacture standard specimens for measuring fracture toughness, such as SENB or CT specimens, from the thin wall of the pipe. Previous works noticed this problem, but until now, a good and convenient solution has not been found or developed. To overcome this problem, very good alternative solution was proposed, the so-called pipe ring notched bend specimen (PRNB) [1-5]. Until now, only the idealized geometry PRNB specimen is analyzed, i. e., a specimen which is not cut out from an actual pipe but produced from steel plate. Based on that, residual stresses are neglected along with the imperfections in geometry (elliptical and eccentricity). The aim of this research is to estimate the residual stress state(s) in real pipes used in the boiler industry produced by hot rolling technique. These types of pipes are delivered only in normalized condition, but not stress relieved. Therefore, there are residual stresses present due to the manufacturing technique, but also due to uneven cooling after the production process. Within this paper, residual stresses are estimated by three methods: the incremental hole drilling method (IHMD), X-ray diffraction (XRD) and the splitting method (SM). Knowing the residual stress state in the ring specimen, it is possible to assess their impact on fracture toughness measured on the corresponding PRNB specimen(s).

Comparison of gross anatomy test scores using traditional specimens vs. QuickTime Virtual Reality animated specimens

Science.gov (United States)

Maza, Paul Sadiri

In recent years, technological advances such as computers have been employed in teaching gross anatomy at all levels of education, even in professional schools such as medical and veterinary medical colleges. Benefits of computer based instructional tools for gross anatomy include the convenience of not having to physically view or dissect a cadaver. Anatomy educators debate over the advantages versus the disadvantages of computer based resources for gross anatomy instruction. Many studies, case reports, and editorials argue for the increased use of computer based anatomy educational tools, while others discuss the necessity of dissection for various reasons important in learning anatomy, such as a three-dimensional physical view of the specimen, physical handling of tissues, interactions with fellow students during dissection, and differences between specific specimens. While many articles deal with gross anatomy education using computers, there seems to be a lack of studies investigating the use of computer based resources as an assessment tool for gross anatomy, specifically using the Apple application QuickTime Virtual Reality (QTVR). This study investigated the use of QTVR movie modules to assess if using computer based QTVR movie module assessments were equal in quality to actual physical specimen examinations. A gross anatomy course in the College of Veterinary Medicine at Cornell University was used as a source of anatomy students and gross anatomy examinations. Two groups were compared, one group taking gross anatomy examinations in a traditional manner, by viewing actual physical specimens and answering questions based on those specimens. The other group took the same examinations using the same specimens, but the specimens were viewed as simulated three-dimensional objects in a QTVR movie module. Sample group means for the assessments were compared. A survey was also administered asking students' perceptions of quality and user-friendliness of the QTVR

Thermal analysis on the specimens for low irradiation temperature below 100degC in the HANARO

Energy Technology Data Exchange (ETDEWEB)

Choi, Myoung-Hwan; Kim, Bong-Goo; Lee, Byung-Chul; Kim, Tae-Kyu [Korea Atomic Energy Research Inst., Daejeon (Korea, Republic of)

2012-03-15

A capsule has been used for an irradiation test of various nuclear materials in the research reactor, HANARO. As a part of the research reactor development project with a plate type fuel, the irradiation tests of beryllium, zircaloy-4 and graphite materials using the capsule will be carried out to obtain the mechanical characteristics at low temperatures below 100degC with 30 MW reactor power. In this study, in order to obtain the preliminary design data of the capsule with various specimens and the temperature of specimens, a thermal analysis is performed by using an ANSYS program. The finite element models for the cross section of the capsule containing the specimen are generated, and the temperatures are evaluated. The analysis results show that most specimens meet the irradiation target temperature. However, some canned graphite specimens have a slightly high temperature, and the gap size has a significant effect on the specimen temperature. Based on those results a detailed design and analysis of the capsule will be completed this year. (author)

Prediction of multiaxial fatigue life for notched specimens of titanium alloy TC4

Energy Technology Data Exchange (ETDEWEB)

Wu, Z. R.; Li, Z. X. [Southeast University, Nanjing (China); Hu, X. T.; Song, Y. D. [Nanjing University, Nanjing (China)

2016-05-15

Both the proportional and nonproportional multiaxial fatigue tests were conducted on two kinds of notched specimens of titanium alloy TC4. The multiaxial fatigue critical area of notched specimen is considered as the location experiencing the maximum damage. It is unsatisfactory to predict the multiaxial fatigue life with the local stress and strain in the fatigue critical area. The critical distance concepts are employed in the multiaxial life prediction method for notched specimens. The proposed method was checked by the test data of TC4 notched specimens. The prediction results are almost within a factor of three scatter band of the test results.

Corrosion resistance of zinc-nickel plated U-O.75 Ti

International Nuclear Information System (INIS)

Dini, J.W.; Johnson, H.R.

1979-09-01

As part of a program for the US Army directed at improving the corrosion performance of U-0.75 Ti, specimens were coated with Zn-10 Ni alloy electroplate and then subjected to various corrosion tests. This work revealed that the Zn-Ni coatings provided good protection for U-0.75 Ti in salt fog and in non-sealed moist-nitrogen systems. In sealed, moist-nitrogen environments the Zn-Ni coatings deteriorated quickly and provided no protection. Some plating with Zn alone, using some of the new non-cyanide plating solutions, was also attempted, but the results were inconsistent

An elastic solution for a new notched residual stess specimen subjected to an anti-clastic loading

DEFF Research Database (Denmark)

Jakobsen, Johnny; Lyckegaard, Anders

A new test specimen has been proposed to explore the mechanical properties of thermoset resin exposed to residual stresses induced by curing and thermal expansion. The test principle is based on anti-clastic bending of a plate with a hole. An elastic solution to the bending problem is derived...

The mechanical benefit of medial support screws in locking plating of proximal humerus fractures.

Directory of Open Access Journals (Sweden)

Wen Zhang

Full Text Available BACKGROUND: The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs in the locking proximal humeral plate for treating proximal humerus fractures. METHODS: Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed. RESULTS: Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001. When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P ≤ 0.0207. Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture. CONCLUSIONS: Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure.

Results of charpy V-notch impact testing of structural steel specimens irradiated at ∼30 degrees C to 1 x 1016 neutrons/cm2 in a commercial reactor cavity

International Nuclear Information System (INIS)

Iskander, S.K.; Stoller, R.E.

1997-04-01

A capsule containing Charpy V-notch (CVN) and mini-tensile specimens was irradiated at ∼ 30 degrees C (∼ 85 degrees F) in the cavity of a commercial nuclear power plant to a fluence of 1 x 10 16 neutrons/cm 2 (> 1MeV). The capsule included six CVN impact specimens of archival High Flux Isotope Reactor A212 grade B ferritic steel and five CVN impact specimens of a well-studied A36 structural steel. This irradiation was part of the ongoing study of neutron-induced damage effects at the low temperature and flux experienced by reactor supports. The plant operators shut down the plant before the planned exposure was reached. The exposure of these specimens produced no significant irradiation-induced embrittlement. Of interest were the data on unirradiated specimens in the L-T orientation machined from a single plate of A36 structural steel, which is the same specification for the structural steel used in some reactor supports. The average CVN energy of five unirradiated specimens obtained from one region of the plate and tested at room temperature was ∼ 99 J, while the energy of 11 unirradiated specimens from other locations of the same plate was 45 J, a difference of ∼ 220%. The CVN impact energies for all 18 specimens ranged from a low of 32 J to a high of 111 J. Moreover, it appears that the University of Kansas CVN impact energy data of the unirradiated specimens at the 100-J level are shifted toward higher temperatures by about 20 K. The results were an example of the extent of scatter possible in CVN impact testing. Generic values for the CVN impact energy of A36 should be used with caution in critical applications

A distal femoral supra-condylar plate: biomechanical comparison with condylar plate and first clinical application for treatment of supracondylar fracture.

Science.gov (United States)

Liang, Bowei; Ding, Zhenqi; Shen, Junguo; Zhai, Wenliang; Kang, Liangqi; Zhou, Liang; Sha, Mo; Liang, Dongzhu

2012-08-01

An anatomical supra-condylar plate is designed and analysed by biomechanical testing. The biomechanical properties of the supra-condylar and condylar plate were compared in six matched pairs of cadaveric femurs. A transverse osteotomy gap was created to simulate an OTA/AO type A3 supracondylar fracture. The left and right specimens were fitted with supra-condylar and condylar plate, respectively. Nondestructive axial compression, three-point bending and torsion tests were performed, and the peak load of the bone-implant construction was measured. The fracture site suitable for supra-condylar plate application and its correlation with femoral length were calculated. The gender influence on it was also discussed. The difference of stiffness between the supra-condylar and condyle groups were not significant (P > 0.05) at 363.4 and 362.5 N/mm for compression, 229.5 and 237.6 N/mm in the sagittal plane and 195.5 and 188.4 N/mm in the coronal plane for three-point bending, and 7.5 and 7.9 Nm/deg for axial torsion, respectively. The peak load was 4438 ± 136.15 N and 5215 ± 174.33 N, respectively, for the two groups. The average extent of the fracture site suitable for the application of the supra-condylar plate was 70.86 ± 4.61 mm. The femoral length and gender showed no influence on it. Despite the limited bone contact area provided by the supra-condylar plate, its construct stiffness is comparable to the condylar plate. The supra-condylar plate can be used to treat carefully-selected extra-articular supracondylar fractures.

Evaluation of wall thinning of piping with reinforcing plates using ECT with controlled exciting field

International Nuclear Information System (INIS)

Ichihara, Toshiaki; Xie, Shejuan; Uchimoto, Tetsuya; Takagi, Toshiyuki

2011-01-01

No effective inspection method exists at present for detection and evaluation of wall thinning under the reinforcing plates to T-tubes in nuclear power plants, and the establishment of the inspection method is highly required. In this study, eddy current testing (ECT) with controlled exciting field is applied to evaluation of wall thinning under the reinforcing plates of T-tubes, and their feasibility is discussed. In order to induce eddy current field in deep region of doubled plates, pulse excitation and probe structures are investigated. Through experiments using specimens simulating tubes with reinforcing plates, it is shown that pulsed ECT and conventional TR type eddy current probe with optimized configuration have a capability of detecting and sizing the wall thinning under reinforcing plates. (author)

Evidence for Sexual Dimorphism in the Plated Dinosaur Stegosaurus mjosi (Ornithischia, Stegosauria) from the Morrison Formation (Upper Jurassic) of Western USA.

Science.gov (United States)

Saitta, Evan Thomas

2015-01-01

Conclusive evidence for sexual dimorphism in non-avian dinosaurs has been elusive. Here it is shown that dimorphism in the shape of the dermal plates of Stegosaurus mjosi (Upper Jurassic, western USA) does not result from non-sex-related individual, interspecific, or ontogenetic variation and is most likely a sexually dimorphic feature. One morph possessed wide, oval plates 45% larger in surface area than the tall, narrow plates of the other morph. Intermediate morphologies are lacking as principal component analysis supports marked size- and shape-based dimorphism. In contrast, many non-sex-related individual variations are expected to show intermediate morphologies. Taphonomy of a new quarry in Montana (JRDI 5ES Quarry) shows that at least five individuals were buried in a single horizon and were not brought together by water or scavenger transportation. This new site demonstrates co-existence, and possibly suggests sociality, between two morphs that only show dimorphism in their plates. Without evidence for niche partitioning, it is unlikely that the two morphs represent different species. Histology of the new specimens in combination with studies on previous specimens indicates that both morphs occur in fully-grown individuals. Therefore, the dimorphism is not a result of ontogenetic change. Furthermore, the two morphs of plates do not simply come from different positions on the back of a single individual. Plates from all positions on the body can be classified as one of the two morphs, and previously discovered, isolated specimens possess only one morph of plates. Based on the seemingly display-oriented morphology of plates, female mate choice was likely the driving evolutionary mechanism rather than male-male competition. Dinosaur ornamentation possibly served similar functions to the ornamentation of modern species. Comparisons to ornamentation involved in sexual selection of extant species, such as the horns of bovids, may be appropriate in predicting the

Elevated-temperature benchmark tests of simply supported beams and circular plates subjected to time-varying loadings

International Nuclear Information System (INIS)

Corum, J.M.; Richardson, M.; Clinard, J.A.

1977-01-01

This report presents the measured elastic-plastic-creep responses of eight simply supported type 304 stainless steel beams and circular plates that were subjected to time-varying loadings at elevated temperature. The tests were performed to provide experimental benchmark problem data suitable for assessing inelastic analysis methods and for validating computer programs. Beams and plates exhibit the essential features of inelastic structural behavior; yet they are relatively simple and the experimental results are generally easy to interpret. The stress fields are largely uniaxial in beams, while multiaxial effects are introduced in plates. The specimens tested were laterally loaded at the center and subjected to either a prescribed load or a center deflection history. The specimens were machined from a common well-characterized heat of material, and all the tests were performed at a temperature of 593 0 C (1100 0 F). Test results are presented in terms of the load and center deflection behaviors, which typify the overall structural behavior. Additional deflection data, as well as strain gage results and mechanical properties data for the beam and plate material, are provided in the appendices

Loading Mode and Environment Effects on Surface Profile Characteristics of Martensite Plates in Cu-Based SMAs

Science.gov (United States)

Suru, Marius-Gabriel; Paraschiv, Adrian-Liviu; Lohan, Nicoleta Monica; Pricop, Bogdan; Ozkal, Burak; Bujoreanu, Leandru-Gheorghe

2014-07-01

The present work reports the influence of the loading mode provided during training under constant stress, in bending, applied to lamellar specimens of Cu-Zn-Al shape memory alloys (SMAs). During training, the specimens were bent by a load fastened at their free end, while being martensitic at room temperature and they lifted the load by one-way effect (1WE), during heating up to austenitic field. On cooling to martensite field, the lower concave surface of bent specimens was compressed, and during heating it was elongated, being subjected to a series of tension-compression cycles, during heating-cooling, respectively. Conversely, the upper convex surface of bent specimens was elongated during cooling and compressed during heating, being subjected to compression-tension cycles. Furthermore, 2WE-trained actuators were tested by means of a hydraulic installation where, this time heating-cooling cycles were performed in oil conditions. Considering that the lower concave surface of the specimens was kept in compressed state, while the upper convex surface was kept in elongated state, the study reveals the influence of the two loading modes and environments on the width of martensite plates of the specimens trained under various numbers of cycles. In this purpose, Cu-Zn-Al specimens, trained under 100-300-500 cycles, were prepared and analyzed by atomic force microscopy (AFM) as well as optical and scanning electron microscopy (OM and SEM, respectively). The analysis also included AFM micrographs corroborated with statistical evaluations in order to reveal the effects of loading mode (tension or compression) in different environmental conditions of the specimens, on the surface profile characteristics of martensite plates, revealed by electropolishing.

Fracture toughness evaluation using small specimens for assuring structural integrity of PRV's

International Nuclear Information System (INIS)

Lee, Bong Sang; Hong, J. H.; Chi, S. H.; Kim, J. H.; Yang, W. J.

1999-08-01

This report summarizes the results obtained from the three year contribution of KAERI to the IAEA-CRP on ''Assuring Structural Integrity of Reactor Pressure Vessels''. The mandatory part of this programme is to perform fracture toughness K jc tests using pre-cracked Charpy specimens on the IAEA reference material JRQ (ASTM A533-B1 steel). The results will be used to validate the small specimens for surveillance tests. In this report, three different heats of reactor pressure vessel materials are characterized by the ASTM E 1921-97 s tandard test method for determination of reference temperature, T o , for ferritic steels in the transition range . The materials are the IAEA reference plate (JRQ), a Japanese forging (JEL), and a Korean forging (KFY5). 6 refs., 7 tabs., 20 figs

Application of MMC model on simulation of shearing process of thick hot-rolled high strength steel plate

Energy Technology Data Exchange (ETDEWEB)

Dong, Liang; Li, Shuhui [Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, Shanghai Jiao Tong University, Shanghai 200240 (China); Yang, Bing; Gao, Yongsheng [Automotive Steel Research Institute, R and D Center, BaoShan Iron and Steel Co.,Ltd, Shanghai 201900 (China)

2013-12-16

Shear operation is widely used as the first step in sheet metal forming to cut the sheet or plate into the required size. The shear of thick hot-rolled High Strength Steel (HSS) requires large shearing force and the sheared edge quality is relatively poor because of the large thickness and high strength compared with the traditional low carbon steel. Bad sheared edge quality will easily lead to edge cracking during the post-forming process. This study investigates the shearing process of thick hot-rolled HSS plate metal, which is generally exploited as the beam of heavy trucks. The Modified Mohr-Coulomb fracture criterion (MMC) is employed in numerical simulation to calculate the initiation and propagation of cracks during the process evolution. Tensile specimens are designed to obtain various stress states in tension. Equivalent fracture strains are measured with Digital Image Correlation (DIC) equipment to constitute the fracture locus. Simulation of the tension test is carried out to check the fracture model. Then the MMC model is applied to the simulation of the shearing process, and the simulation results show that the MMC model predicts the ductile fracture successfully.

Application of MMC model on simulation of shearing process of thick hot-rolled high strength steel plate

International Nuclear Information System (INIS)

Dong, Liang; Li, Shuhui; Yang, Bing; Gao, Yongsheng

2013-01-01

Shear operation is widely used as the first step in sheet metal forming to cut the sheet or plate into the required size. The shear of thick hot-rolled High Strength Steel (HSS) requires large shearing force and the sheared edge quality is relatively poor because of the large thickness and high strength compared with the traditional low carbon steel. Bad sheared edge quality will easily lead to edge cracking during the post-forming process. This study investigates the shearing process of thick hot-rolled HSS plate metal, which is generally exploited as the beam of heavy trucks. The Modified Mohr-Coulomb fracture criterion (MMC) is employed in numerical simulation to calculate the initiation and propagation of cracks during the process evolution. Tensile specimens are designed to obtain various stress states in tension. Equivalent fracture strains are measured with Digital Image Correlation (DIC) equipment to constitute the fracture locus. Simulation of the tension test is carried out to check the fracture model. Then the MMC model is applied to the simulation of the shearing process, and the simulation results show that the MMC model predicts the ductile fracture successfully

Application of generalized function to dynamic analysis of thick plates

International Nuclear Information System (INIS)

Zheng, D.; Weng, Z.

1987-01-01

The structures with thick plates have been used extensively in national defence, mechanical engineering, chemical engineering, nuclear engineering, civil engineering, etc.. Various theories have been established to deal with the problems of elastic plates, which include the classical theory of thin plates, the improved theory of thick plates, three-dimensional elastical theory. In this paper, the derivative of δ-function is handled by using the generalized function. The dynamic analysis of thick plates subjected the concentrated load is presented. The improved Donnell's equation of thick plates is deduced and employed as the basic equation. The generalized coordinates are solved by using the method of MWR. The general expressions for the dynamic response of elastic thick plates subjected the concentrated load are given. The numerical results for rectangular plates are given herein. The results are compared with those obtained from the improved theory and the classical theory of plates. (orig./GL)

Phase zone plates as condensers for the Gottingen scanning x-ray microscope

International Nuclear Information System (INIS)

Hilkenbach, R.; Thieme

1987-01-01

With the Gottingen scanning x-ray microscope the synchrotron source is image by x-ray optics into a monochromatic small scan spot, through which a specimen can be moved. Hereby one part of the optics, the condenser zone plate and a pinhole, works as a linear monochromator in the wavelength region of λ = 2.36 nm to λ = 4.5 nm. The efficiency of such a condenser should be as high as possible to minimize the loss of radiation. Phase zone plates have a four times higher efficiency in the first order of diffraction than amplitude zone plates. Two condenser zone plates, KZP4 and KZP5, have been constructed so that they are well suited for the use in the scanning microscope. These zone plates have been made holographically by superposing two wavefronts of laser light in an specific designed optical arrangement and exposing the zone plate structure into a photoresist. Using reactive ion etching (RIE) the structure has been transformed into Germanium. The thickness of the zone plate has been chosen to show at λ = 2.36 nm a phase effect. The efficiency has been measured at the Berliner Elektronenspeircherring Gesellschaft fur Synchrotronstrahlung m.b.H., Berlin

The plantar plate of the first metatarsophalangeal joint: an anatomical study.

Science.gov (United States)

Lucas, Douglas E; Philbin, Terrence; Hatic, Safet

2014-04-01

The plantar plate of the first metatarsophalangeal (MP) joint is a critical structure of the forefoot that has been identified as a major stabilizer within the capsuloligamentous complex. Many studies have clarified and documented the anatomy of the lesser toe MP plantar plates, but few have looked closely at the anatomy of the first MP joint. Ten cadaveric specimens were examined to identify and document the objective anatomic relationship of the plantar plate, tibial sesamoid, and surrounding osseus structures. The average distance of the plantar plate distal insertion from the joint line into the proximal phalanx was 0.33 mm. The plantar plate was inserted into the metatarsal head on average 17.29 mm proximal from the joint line. The proximal aspect of the sesamoid was 18.55 mm proximal to the distal attachment of the plantar plate to the phalanx. The distal aspect of the sesamoid averaged 4.69 mm away from the distal attachment into the proximal phalanx. The footprint of the distal plate insertion was on average 6.33 mm in length in the sagittal plane. The authors hope that these objective data measures can aid in the understanding and subsequent surgical repair of this important forefoot structure.

A system for mapping radioactive specimens

International Nuclear Information System (INIS)

Britten, R.J.; Davidson, E.H.

1988-01-01

A system for mapping radioactive specimens comprises an avalanche counter, an encoder, pre-amplifier circuits, sample and hold circuits and a programmed computer. The parallel plate counter utilizes avalanche event counting over a large area with the ability to locate radioactive sources in two dimensions. When a beta ray, for example, enters a chamber, an ionization event occurs and the avalanche effect multiplies the event and results in charge collection on the anode surface for a limited period of time before the charge leaks away. The encoder comprises a symmetrical array of planar conductive surfaces separated from the anode by a dielectric material. The encoder couples charge currents, the amlitudes of which define the relative position of the ionization event. The amplitude of coupled current, delivered to pre-amplifiers, defines the location of the event. (author) 12 figs

Application of small specimens to fracture mechanics characterization of irradiated pressure vessel steels

International Nuclear Information System (INIS)

Sokolov, M.A.; Wallin, K.; McCabe, D.E.

1996-01-01

In this study, precracked Charpy V-notch (PCVN) specimens were used to characterize the fracture toughness of unirradiated and irradiated reactor pressure vessel steels in the transition region by means of three-point static bending. Fracture toughness at cleavage instability was calculated in terms of elastic-plastic K Jc values. A statistical size correction based upon weakest-link theory was performed. The concept of a master curve was applied to analyze fracture toughness properties. Initially, size-corrected PCVN data from A 533 grade B steel, designated HSST Plate O2, were used to position the master curve and a 5% tolerance bound for K Jc data. By converting PCVN data to IT compact specimen equivalent K Jc data, the same master curve and 5% tolerance bound curve were plotted against the Electric Power Research Institute valid linear-elastic K Jc database and the ASME lower bound K Ic curve. Comparison shows that the master curve positioned by testing several PCVN specimens describes very well the massive fracture toughness database of large specimens. These results give strong support to the validity of K Jc with respect to K Ic in general and to the applicability of PCVN specimens to measure fracture toughness of reactor vessel steels in particular. Finally, irradiated PCVN specimens of other materials were tested, and the results are compared to compact specimen data. The current results show that PCVNs demonstrate very good capacity for fracture toughness characterization of reactor pressure vessel steels. It provides an opportunity for direct measurement of fracture toughness of irradiated materials by means of precracking and testing Charpy specimens from surveillance capsules. However, size limits based on constraint theory restrict the operational test temperature range for K Jc data from PCVN specimens. 13 refs., 8 figs., 1 tab

Electroless nickel-plating for the PWSCC mitigation of nickel-base alloys in nuclear power plants

International Nuclear Information System (INIS)

Kim, Ji Hyun; Hwang, Il Soon

2008-01-01

The feasibility study has been performed as an effort to apply the electroless nickel-plating method for a proposed countermeasure to mitigate primary water stress corrosion cracking (PWSCC) of nickel-base alloys in nuclear power plants. In order to understand the corrosion behavior of nickel-plating at high temperature water, the electrochemical properties of electroless nickel-plated alloy 600 specimens exposed to simulated pressurized water reactor (PWR) primary water were experimentally characterized in high temperature and high pressure water condition. And, the resistance to the flow accelerated corrosion (FAC) test was investigated to check the durability of plated layers in high-velocity water-flowing environment at high temperature. The plated surfaces were examined by using both scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) after exposures to the condition. From this study, it is found that the corrosion resistance of electroless nickel-plated Alloy 600 is higher than that of electrolytic plating in 290 deg. C water

3D FDM production and mechanical behavior of polymeric sandwich specimens embedding classical and honeycomb cores

Science.gov (United States)

Brischetto, Salvatore; Ferro, Carlo Giovanni; Torre, Roberto; Maggiore, Paolo

2018-04-01

Desktop 3D FDM (Fused Deposition Modelling) printers are usually employed for the production of nonstructural objects. In recent years, the present authors tried to use this technology also to produce structural elements employed in the construction of small UAVs (Unmanned Aerial Vehicles). Mechanical stresses are not excessive for small multirotor UAVs. Therefore, the FDM technique combined with polymers, such as the ABS (Acrylonitrile Butadiene Styrene) and the PLA(Poly Lactic Acid), can be successfully employed to produce structural components. The present new work is devoted to the production and preliminary structural analysis of sandwich configurations. These new lamination schemes could lead to an important weight reduction without significant decreases of mechanical properties. Therefore, it could be possible, for the designed application (e.g., a multifunctional small UAV produced via FDM), to have stiffener and lighter structures easy to be manufactured with a low-cost 3D printer. The new sandwich specimens here proposed are PLA sandwich specimens embedding a PLA honeycomb core produced by means of the same extruder, multilayered specimens with ABS external layers and an internal homogeneous PLA core using different extruders for the two materials, sandwich specimens with external ABS skins and an internal PLA honeycomb core using different extruders for the two materials, and sandwich specimens where two different extruders have been employed for PLA material used for skins and for the internal honeycomb core. For all the proposed configurations, a detailed description of the production activity is given.Moreover, several preliminary results about three-point bending tests, different mechanical behaviors and relative delamination problems for each sandwich configuration will be discussed in depth.

Preliminary investigation of candidate specimens for the Egyptian environmental specimen bank

International Nuclear Information System (INIS)

Shawky, S.; Amer, H.; Schladot, J.D.; Ostapczuk, P.; Emons, H.; Abou El-Nour, F.

2000-01-01

In the frame of establishing an environmental monitoring program related to environmental specimen banking in egypt, some candidate specimens from the aquatic environment (Fish muscle, fish liver; mussels) were investigated. The selection of specimens and sampling sites is described. Specimens are chemically characterised with respect to some major and trace elements and the results are compared with data obtained from comparable specimens collected in aquatic ecosystems of germany

49 CFR 40.105 - What happens if the laboratory reports a result different from that expected for a blind specimen?

Science.gov (United States)

2010-10-01

... different from that expected for a blind specimen? 40.105 Section 40.105 Transportation Office of the... for a blind specimen? (a) If you are an employer, MRO, or C/TPA who submits a blind specimen, and if... expected results (obtained from the supplier of the blind specimen), and direct the laboratory to determine...

Transmission electron microscopy of bulk specimens over 10 µm in thickness

Energy Technology Data Exchange (ETDEWEB)

Sadamatsu, Sunao, E-mail: sadamatsu@mech.kagoshima-u.ac.jp [Department of Mechanical Engineering, Kagoshima University, Korimoto, Kagoshima 890-0065 (Japan); Tanaka, Masaki; Higashida, Kenji [Department of Materials Science and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395 (Japan); Matsumura, Syo [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395 (Japan); Ultramicroscopy Research Center, Kyushu University, Nishi-ku, Fukuoka 819-0395 (Japan)

2016-03-15

We succeeded the observation of microstructures in bulk-sized specimens of over 10 µm in thickness by employing a technique that combines transmission electron microscopy (TEM) with energy-filtered imaging based on electron energy-loss spectroscopy (EELS). This method is unique in that it incorporates the inelastically scattered electrons into the imaging process. Using this technique, bright and sharp images of dislocations in crystalline silicon specimens as thick as 10 µm were obtained. A calibration curve to determine foil thickness of such a thick specimen was also derived. This method simply extends the observable thickness range in TEM. If combined with tilt series of observation over a significant range of angle, it will disclose three dimensional nanostructures in a µm-order block of a specimen, promoting our understanding of the controlling mechanisms behind various bulky material properties. - Highlights: • We developed a method which enables thick specimens to be observed using EF-TEM. • The effects of energy filter width and position on images were determined. • We suggested a method to determine the thickness of a thick film sample. • We achieved observation of microstructures in specimens with a thickness of 10 µm.

Neutron Diffraction Residual Strain Tensor Measurements Within The Phase IA Weld Mock-up Plate P-5

Energy Technology Data Exchange (ETDEWEB)

Hubbard, Camden R [ORNL

2011-09-01

Oak Ridge National Laboratory (ORNL) has worked with NRC and EPRI to apply neutron and X-ray diffraction methods to characterize the residual stresses in a number of dissimilar metal weld mockups and samples. The design of the Phase IA specimens aimed to enable stress measurements by several methods and computational modeling of the weld residual stresses. The partial groove in the 304L stainless steel plate was filled with weld beads of Alloy 82. A summary of the weld conditions for each plate is provided in Table 1. The plates were constrained along the long edges during and after welding by bolts with spring-loaded washers attached to the 1-inch thick Al backing plate. The purpose was to avoid stress relief due to bending of the welded stainless steel plate. The neutron diffraction method was one of the methods selected by EPRI for non-destructive through thickness strain and stress measurement. Four different plates (P-3 to P-6) were studied by neutron diffraction strain mapping, representing four different welding conditions. Through thickness neutron diffraction strain mappings at NRSF2 for the four plates and associated strain-free d-zero specimens involved measurement along seven lines across the weld and at six to seven depths. The mountings of each plate for neutron diffraction measurements were such that the diffraction vector was parallel to each of the three primary orthogonal directions of the plate: two in-plane directions, longitudinal and transverse, and the direction normal to the plate (shown in left figure within Table 1). From the three orthogonal strains for each location, the residual stresses along the three plate directions were calculated. The principal axes of the strain and stress tensors, however, need not necessarily align with the plate coordinate system. To explore this, plate P-5 was selected for examination of the possibility that the principal axes of strain are not along the sample coordinate system axes. If adequate data could

Concrete containment tests: Phase 2, Structural elements with liner plates: Interim report

International Nuclear Information System (INIS)

Hanson, N.W.; Roller, J.J.; Schultz, D.M.; Julien, J.T.; Weinmann, T.L.

1987-08-01

The tests described in this report are part of Phase 2 of the Electric Power Research Institute (EPRI) program. The overall objective of the EPRI program is to provide a test-verified analytical method of estimating capacities of concrete reactor containment buildings under internal overpressurization from postulated degraded core accidents. The Phase 2 testing included seven large-scale specimens representing structural elements from reinforced and prestressed concrete reactor containment buildings. Six of the seven test specimens were square wall elements. Of these six specimens, four were used for biaxial tension tests to determine strength, deformation, and leak-rate characteristics of full-scale wall elements representing prestressed concrete containment design. The remaining two square wall elements were used for thermal buckling tests to determine whether buckling of the steel liner plate would occur between anchorages when subjected to a sudden extreme temperature differential. The last of the seven test specimens for Phase 2 represented the region where the wall and the basemat intersect in a prestressed concrete containment building. A multi-directional loading scheme was used to produce high bending moments and shear in the wall/basemat junction region. The objective of this test was to determine if there is potential for liner plate tearing in the junction region. Results presented include observed behavior and extensive measurements of deformations and strains as a function of applied load. The data are being used to confirm analytical models for predicting strength and deformation of containment structures in a separate parallel analytical investigation sponsored by EPRI

Active structural health monitoring of composite plates and sandwiches

Directory of Open Access Journals (Sweden)

Sadílek P.

2013-12-01

Full Text Available The aim of presented work is to design, assemble and test a functional system, that is able to reveal damage from impact loading. This is done by monitoring of change of spectral characteristics on a damaged structure that is caused by change of mechanical properties of material or by change of structure’s geometry. Excitation and monitoring of structures was done using piezoelectric patches. Unidirectional composite plate was tested for eigenfrequencies using chirp signal. The eigenfrequencies were compared to results from experiments with an impact hammer and consequently with results from finite element method. Same method of finding eigenfrequencies was used on a different unidirectional composite specimen. Series of impacts were performed. Spectrum of eigenfrequencies was measured on undamaged plate and then after each impact. Measurements of the plate with different level of damage were compared. Following experiments were performed on sandwich materials where more different failures may happen. Set of sandwich beams (cut out from one plate made of two outer composite layers and a foam core was investigated and subjected to several impacts. Several samples were impacted in the same manner to get comparable results. The impacts were performed with growing impact energy.

Stress analysis of perforated plates and plates with single and clustered nozzles

International Nuclear Information System (INIS)

Hulbert, L.E.; Hopper, A.T.; Rybicki, E.F.

1976-01-01

It is well known that stress distributions around a hole in a plate are drastically increased if there are other holes in the plate sufficiently near. Such stress interaction effects must be analyzed and accounted for in the design of a plate containing multiple perforations. Computer programs have been developed for the accurate analysis of the in-plane stresses of arbitrary multiholed plates. Stress interactions also occur between closely spaced nozzles attached to pressure vessels such as nuclear reactor vessels. Results of the investigations carried out during the second year of the research program are summarized. The first section of the report describes the structures analyzed, the loadings on these structures, and the mathematical statements of these problems. The second section explains the analysis techniques employed. The third section deals with the numerical results obtained for all of the problems solved. This section also gives a complete statement of each problem and the series of trial functions used to solve each nozzle-plate problem. Several appendices are also included. These appendices are intended to be users' manuals for the computer codes used in this research effort but which are not explained in the literature. Appendix A treats program TABLES while Appendix B explains the use of PEBBLES. Appendix C is the users' manual for program INTRTIE which is a large program actually consisting of six individual programs. Appendix D discusses the changes in the input data to program NONLIN to obtain certain input data for INTRTIE. Finally, Appendix E treats a small program called CONVERT which also generates input data for INTRTIE

Experimental and numerical analysis concerning the behaviour of OL50 steel grade specimens coated with polyurea layer under dynamics loadings

Directory of Open Access Journals (Sweden)

Bucur Florina

2015-01-01

Full Text Available This study refers to an experimental and numerical evaluation of a polyurea coating layer influence on the dynamic behaviour of OL50 specimens. Mechanical quasi-static and dynamic tensile tests were performed in axial loading conditions, for 2 mm steel plate specimens. Several metallic specimens have been previously coated with 1.5 mm and 3 mm respectively thickness polyurea layer and tested in traction. The findings results indicate that the presence of polyurea changes the loading pattern of metallic material in the necking area. In terms of polyurea coated metal specimens fracture, there was clearly observed a change of fracture limit. One possible explanation of this phenomenon is the modification of triaxiality state in the necking zone, fact proven by the numerical simulations. Test results indicate that the presence of polyurea layer delays the necking onset phenomenon which precedes the OL50 metallic specimen fracture.

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...

Impact of specimen adequacy on the assessment of renal allograft biopsy specimens.

Science.gov (United States)

Cimen, S; Geldenhuys, L; Guler, S; Imamoglu, A; Molinari, M

2016-01-01

The Banff classification was introduced to achieve uniformity in the assessment of renal allograft biopsies. The primary aim of this study was to evaluate the impact of specimen adequacy on the Banff classification. All renal allograft biopsies obtained between July 2010 and June 2012 for suspicion of acute rejection were included. Pre-biopsy clinical data on suspected diagnosis and time from renal transplantation were provided to a nephropathologist who was blinded to the original pathological report. Second pathological readings were compared with the original to assess agreement stratified by specimen adequacy. Cohen's kappa test and Fisher's exact test were used for statistical analyses. Forty-nine specimens were reviewed. Among these specimens, 81.6% were classified as adequate, 6.12% as minimal, and 12.24% as unsatisfactory. The agreement analysis among the first and second readings revealed a kappa value of 0.97. Full agreement between readings was found in 75% of the adequate specimens, 66.7 and 50% for minimal and unsatisfactory specimens, respectively. There was no agreement between readings in 5% of the adequate specimens and 16.7% of the unsatisfactory specimens. For the entire sample full agreement was found in 71.4%, partial agreement in 20.4% and no agreement in 8.2% of the specimens. Statistical analysis using Fisher's exact test yielded a P value above 0.25 showing that - probably due to small sample size - the results were not statistically significant. Specimen adequacy may be a determinant of a diagnostic agreement in renal allograft specimen assessment. While additional studies including larger case numbers are required to further delineate the impact of specimen adequacy on the reliability of histopathological assessments, specimen quality must be considered during clinical decision making while dealing with biopsy reports based on minimal or unsatisfactory specimens.

Evaluation of Electron Beam Welding Performance of AA6061-T6 Plate-type Fuel Assembly

International Nuclear Information System (INIS)

Kim, Soo-Sung; Seo, Kyoung-Seok; Lee, Don-Bae; Park, Jong-Man; Lee, Yoon-Sang; Lee, Chong-Tak

2014-01-01

As one of the most commonly used heat-treatable aluminum alloys, AA6061-T6 aluminum alloy is available in a wide range of structural materials. Typically, it is used in structural members, auto-body sheet and many other applications. Generally, this alloy is easily welded by conventional GTAW (Gas Tungsten Arc Welding), LBW (Laser Beam Welding) and EBW(Electron Beam Welding). However, certain characteristics, such as solidification cracking, porosity, HAZ (Heat-affected Zone) degradation must be considered during welding. Because of high energy density and low heat input, especially LBW and EBW processes possess the advantage of minimizing the fusing zone and HAZ and producing deeper penetration than arc welding processes. In present study, to apply for the plate-type nuclear fuel fabrication and assembly, a fundamental electron beam welding experiment using AA6061-T6 aluminum alloy specimens was conducted. Furthermore, to establish the suitable welding process, and satisfy the requirements of the weld quality, EBW apparatus using an electron welding gun and vacuum chamber was developed, and preliminary investigations for optimizing the welding parameters of the specimens using AA6061-T6 aluminum plates were also performed. The EB weld quality of AA6061-T6 aluminum alloy for the plate-type fuel assembly has been also studied by the weld penetrations of side plate to end fitting and fixing bar and weld inspections using computed tomography

Functional imaging in bulk tissue specimens using optical emission tomography: fluorescence preservation during optical clearing

International Nuclear Information System (INIS)

Sakhalkar, H S; Dewhirst, M; Oliver, T; Cao, Y; Oldham, M

2007-01-01

Optical emission computed tomography (optical-ECT) is a technique for imaging the three-dimensional (3D) distribution of fluorescent probes in biological tissue specimens with high contrast and spatial resolution. In optical-ECT, functional information can be imaged by (i) systemic application of functional labels (e.g. fluorophore labelled proteins) and/or (ii) endogenous expression of fluorescent reporter proteins (e.g. red fluorescent protein (RFP), green fluorescent protein (GFP)) in vivo. An essential prerequisite for optical-ECT is optical clearing, a procedure where tissue specimens are made transparent to light by sequential perfusion with fixing, dehydrating and clearing agents. In this study, we investigate clearing protocols involving a selection of common fixing (4% buffered paraformaldehyde (PFA), methanol and ethanol), dehydrating (methanol and ethanol) and clearing agents (methyl salicylate and benzyl-alcohol-benzyl-benzoate (BABB)) in order to determine a 'fluorescence friendly' clearing procedure. Cell culture experiments were employed to optimize the sequence of chemical treatments that best preserve fluorescence. Texas red (TxRed), fluorescein isothiocyanate (FITC), RFP and GFP were tested as fluorophores and fluorescent reporter proteins of interest. Fluorescent and control cells were imaged on a microscope using a DSred2 and FITC filter set. The most promising clearing protocols of cell culture experiments were applied to whole xenograft tumour specimens, to test their effectiveness in large unsectioned samples. Fluorescence of TxRed/FITC fluorophores was not found to be significantly affected by any of the test clearing protocols. RFP and GFP fluorescence, however, was found to be significantly greater when cell fixation was in ethanol. Fixation in either PFA or methanol resulted in diminished fluorescence. After ethanol fixation, the RFP and GFP fluorescence proved remarkably robust to subsequent exposure to either methyl salicylate or BABB

Functional imaging in bulk tissue specimens using optical emission tomography: fluorescence preservation during optical clearing

Energy Technology Data Exchange (ETDEWEB)

Sakhalkar, H S [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States); Dewhirst, M [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States); Oliver, T [Department of Cell Biology, Duke University Medical Center, Durham, NC 27710 (United States); Cao, Y [Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710 (United States); Oldham, M [Department of Radiation Oncology Physics, and Biomedical Engineering, Duke University Medical Center, Durham, NC 27710 (United States)

2007-04-21

Optical emission computed tomography (optical-ECT) is a technique for imaging the three-dimensional (3D) distribution of fluorescent probes in biological tissue specimens with high contrast and spatial resolution. In optical-ECT, functional information can be imaged by (i) systemic application of functional labels (e.g. fluorophore labelled proteins) and/or (ii) endogenous expression of fluorescent reporter proteins (e.g. red fluorescent protein (RFP), green fluorescent protein (GFP)) in vivo. An essential prerequisite for optical-ECT is optical clearing, a procedure where tissue specimens are made transparent to light by sequential perfusion with fixing, dehydrating and clearing agents. In this study, we investigate clearing protocols involving a selection of common fixing (4% buffered paraformaldehyde (PFA), methanol and ethanol), dehydrating (methanol and ethanol) and clearing agents (methyl salicylate and benzyl-alcohol-benzyl-benzoate (BABB)) in order to determine a 'fluorescence friendly' clearing procedure. Cell culture experiments were employed to optimize the sequence of chemical treatments that best preserve fluorescence. Texas red (TxRed), fluorescein isothiocyanate (FITC), RFP and GFP were tested as fluorophores and fluorescent reporter proteins of interest. Fluorescent and control cells were imaged on a microscope using a DSred2 and FITC filter set. The most promising clearing protocols of cell culture experiments were applied to whole xenograft tumour specimens, to test their effectiveness in large unsectioned samples. Fluorescence of TxRed/FITC fluorophores was not found to be significantly affected by any of the test clearing protocols. RFP and GFP fluorescence, however, was found to be significantly greater when cell fixation was in ethanol. Fixation in either PFA or methanol resulted in diminished fluorescence. After ethanol fixation, the RFP and GFP fluorescence proved remarkably robust to subsequent exposure to either methyl salicylate

Coupled oscillations of flow along a perforated plate

International Nuclear Information System (INIS)

Celik, E.; Rockwell, D.

2004-01-01

Turbulent shear flow past a perforated plate bounded by a closed cavity can give rise to highly coherent oscillations, which have a wavelength of the order of the plate length. The present investigation focuses on the coupling between unsteady events on either side of the plate when the oscillations are self-sustaining. A cinema technique of high-image-density particle image velocimetry, which provides a space-time representation of the unsteadiness at a large number of locations over entire planes, is employed to characterize the distinctively different patterns of flow structure on the back (low-speed) side of the plate relative to those on the front (high-speed) side. Global cross-spectral analysis leads to patterns of spectral peaks and phase variations, along and across the plate. This approach, along with complementary types of image evaluation, delineates the physics of the oscillations, which include downstream propagating disturbances along either side of the plate and a coherent region of unsteadiness at its trailing-edge. On the backside of the plate, a sequence of upstream-oriented, pulsatile jets are formed, and the time-averaged flow pattern is a counterflow wall jet

Width of electromagnetic wave instability spectrum in tungsten plate

International Nuclear Information System (INIS)

Rinkevich, A.B.

1995-01-01

Based on the study of high-frequency signal modulation and spectrum analysis of the envelope a measurement of spectrum width for electromagnetic wave instability was carried out under conditions of current pulse action on tungsten plate in magnetic field. The existence of amplitude-frequency wave modulation was revealed. The width of current disturbance spectrum in a specimen was evaluated. Current disturbances are shown to cause the instability of electromagnetic wave. 11 refs.; 6 figs

Comparison between instrumented precracked Charpy and compact specimen tests of carbon steels

International Nuclear Information System (INIS)

Nanstad, R.K.

1980-01-01

The General Atomic Company High Temperature Gas-Cooled Reactor (HTGR) is housed within a prestressed concrete reactor vessel (PCRV). Various carbon steel structural members serve as closures at penetrations in the vessel. A program of testing and evaluation is underway to determine the need for reference fracture toughness (K/sub IR/) and indexing procedures for these materials as described in Appendix G to Section III, ASME Code for light water reactor steels. The materials of interest are carbon steel forgings (SA508, Class 1) and plates (SA537, Classes 1 and 2) as well as weldments of these steels. The fracture toughness behavior is characterized with instrumented precracked Charpy V-votch specimens (PCVN) - slow-bend and dynamic - and compact specimens (10-mm and 25-mm thicknesses) using both linear elastic (ASTM E399) and elastic-plastic (equivalent Energy and J-Integral) analytical procedures. For the dynamic PCVN tests, force-time traces are analyzed according to the procedures of the Pressure Vessel Research Council (PVRC)/Metal Properties Council (MPC). Testing and analytical procedures are discussed and PCVN results are compared to those obtained with compact specimens

Replacement divider plate performance under LOCA loading

International Nuclear Information System (INIS)

Huynk, H.M.; MClellan, G.H.; Schneider, W.G.

1997-01-01

A primary divider plate in a nuclear steam generator is required to perform its partitioning function with a minimum of cross leakage, without degradation in operating performance and without loss of structural integrity resulting from normal and accident loading. The design of the replacement divider plate for normal operating conditions is discussed in some detail in reference 1 and 2. This paper describes the structural response of the replacement divider plate to the severe loading resulting from a burst primary pipe. The loads for which the divider plate structural performance must be evaluated are mild to severe differential pressure transients resulting from several postulated sizes and types of pipe break scenarios. In the unlikely event of a severe Loss of Coolant Accident (LOCA) the divider plate or parts thereof must not exit the steam generator nor completely block the outlet nozzle. For the milder LOCA loads, the integrity of the divider plate and seat bars must be maintained. Analysis for the milder LOCA loads was carried out employing a conservative approach which ignores the actual interaction between the structure and the primary fluid. For these load cases it was shown that the divider plate does not become disengaged from the seat bars. For the more severe pipe breaks, the thermal-hydraulic analysis was coupled iteratively with the structural analysis, thereby taking into account divider plate deformation, in order to obtain a better prediction of the behaviour of the divider plate. In this manner substantial reduction in divider plate response to the more severe LOCA loading was achieved. It has been shown that, for the case of a postulated large LOCA (100% reactor inlet header), the disengagement of the divider plate from the seat bars resulted in an opening smaller than 1% of the divider plate area. (author)

A Modified Kirchhoff plate theory for Free Vibration analysis of functionally graded material plates using meshfree method

Science.gov (United States)

Nguyen Van Do, Vuong

2018-04-01

In this paper, a modified Kirchhoff theory is presented for free vibration analyses of functionally graded material (FGM) plate based on modified radial point interpolation method (RPIM). The shear deformation effects are taken account into modified theory to ignore the locking phenomenon of thin plates. Due to the proposed refined plate theory, the number of independent unknowns reduces one variable and exists with four degrees of freedom per node. The simulated free vibration results employed by the modified RPIM are compared with the other analytical solutions to verify the effectiveness and the accuracy of the developed mesh-free method. Detail parametric studies of the proposed method are then conducted including the effectiveness of thickness ratio, boundary condition and material inhomogeneity on the sample problems of square plates. Results illustrated that the modified mesh-free RPIM can effectively predict the numerical calculation as compared to the exact solutions. The obtained numerical results are indicated that the proposed method are stable and well accurate prediction to evaluate with other published analyses.

Through thickness property variations in a thick plate AA7050 friction stir welded joint

International Nuclear Information System (INIS)

Canaday, Clinton T.; Moore, Matthew A.; Tang, Wei; Reynolds, A.P.

2013-01-01

In this study, moderately thick (32 mm) AA7050 plates were joined by friction stir welding (FSW). Various methods were used to characterize the welded joints, including nugget grain size measurements at different locations through the thickness, micro-hardness indentation through nugget, thermo-mechanically affected zone (TMAZ), and heat affected zone (HAZ) at different cross section heights, and residual stress measurement using the cut compliance method with full thickness and partial thickness specimens. All testing results are consistent with the presence of a strong gradient in peak temperature through the plate thickness during FSW.

Effect of specimen geometry on the variability in fatigue crack growth rate

International Nuclear Information System (INIS)

Tsuji, Hirokazu; Nakajima, Hajime; Kondo, Tatsuo

1982-02-01

Fatigue crack growth tests on SA 533 grade B class 1 steel were conducted in air with both contoured double cantilever beam (CDCB) specimens and compact-tension (CT) specimens for comparison, which corresponded to the ΔK constant and ΔK increasing fatigue tests respectively. The variability of the measured values was examined statistically, and possible sources of the determined variability were discussed. The variability in the ΔK increasing fatigue tests with the CT specimens was found to be substantially greater than that in the ΔK constant fatigue tests with the CDCB specimens employed in the present study. In addition, the width of the scatter as well as in the degree of deviation from the expected linearity in da/dN versus ΔK plots were found to be varied depending on the level of ΔK in the CT specimen. Based on the results, a conclusion was drawn that constant ΔK type tests should be preferred in the tests where accuracy and reproducibility of crack growth rate measurement was of particular importance. (author)

Global Dynamic Numerical Simulations of Plate Tectonic Reorganizations

Science.gov (United States)

Morra, G.; Quevedo, L.; Butterworth, N.; Matthews, K. J.; Müller, D.

2010-12-01

We use a new numerical approach for global geodynamics to investigate the origin of present global plate motion and to identify the causes of the last two global tectonic reorganizations occurred about 50 and 100 million years ago (Ma) [1]. While the 50 Ma event is the most well-known global plate-mantle event, expressed by the bend in the Hawaiian-Emperor volcanic chain, a prominent plate reorganization at about 100 Ma, although presently little studied, is clearly indicated by a major bend in the fracture zones in the Indian Ocean and by a change in Pacific plate motion [2]. Our workflow involves turning plate reconstructions into surface meshes that are subsequently employed as initial conditions for global Boundary Element numerical models. The tectonic setting that anticipates the reorganizations is processed with the software GPlates, combining the 3D mesh of the paleo-plate morphology and the reconstruction of paleo-subducted slabs, elaborated from tectonic history [3]. All our models involve the entire planetary system, are fully dynamic, have free surface, are characterized by a spectacular computational speed due to the simultaneous use of the multi-pole algorithm and the Boundary Element formulation and are limited only by the use of sharp material property variations [4]. We employ this new tool to unravel the causes of plate tectonic reorganizations, producing and comparing global plate motion with the reconstructed ones. References: [1] Torsvik, T., Müller, R.D., Van der Voo, R., Steinberger, B., and Gaina, C., 2008, Global Plate Motion Frames: Toward a unified model: Reviews in Geophysics, VOL. 46, RG3004, 44 PP., 2008 [2] Wessel, P. and Kroenke, L.W. Pacific absolute plate motion since 145 Ma: An assessment of the fixed hot spot hypothesis. Journal of Geophysical Research, Vol 113, B06101, 2008 [3] L. Quevedo, G. Morra, R. D. Mueller. Parallel Fast Multipole Boundary Element Method for Crustal Dynamics, Proceeding 9th World Congress and 4th Asian

An Edge-Based Macao License Plate Recognition System

Directory of Open Access Journals (Sweden)

Chi-Man Pun

2011-04-01

Full Text Available This paper presents a system to recognize Macao license plates. Sobel edge detector is employed to extract the vertical edges, and an edge composition algorithm is proposed to combine the edges into candidate plate regions. They are further examined on the existence of the character qMq by a verification algorithm. A row separation algorithm is also proposed to cater both one-row and two-row types of plates. Projection analysis and template matching methods are exploited to segment and recognize the characters. Various pre and post processing steps are proposed other than traditional implementation so as to improve the recognition accuracy. This work achieves a high recognition rate of 95%.

International interest in the BONAPARTE measurement bench. Post-irradiation examination of lower-enriched fuel plates

International Nuclear Information System (INIS)

2014-01-01

The Belgian Nuclear Research Center SCK-CEN has developed a measurement bench (BONAPARTE) for the non-destructive analysis on fuel plate and rod type fuel elements. BONAPARTE is a modular device that can be employed for many purposes. The article discusses the employment of the BONAPARTE device for the accurate full post-irradiation mapping of fuel plate swelling with degree of precision of just a few micrometers.

Creep deformation behavior of weld metal and heat affected zone on 316FR steel thick plate welded joint

International Nuclear Information System (INIS)

Hongo, Hiromichi; Yamazaki, Masayoshi; Watanabe, Takashi; Kinugawa, Junichi; Tanabe, Tatsuhiko; Monma, Yoshio; Nakazawa, Takanori

1999-01-01

Using hot-rolled 316FR stainless plate (50 mm thick) and 16Cr-8Ni-2Mo filler wire, a narrow-gap welded joint was prepared by GTAW (gas tungsten arc welding) process. In addition to conventional round bar specimens of base metals and weld metal, full-thickness joint specimens were prepared for creep test. Creep tests were conducted at 550degC in order to examine creep deformation and rupture behavior in the weld metal of the welded joint. Creep strain distribution on the surface of the joint specimen was measured by moire interferometry. In the welded joint, creep strength of the weld metal zone apart from the surface was larger than that in the vicinity of the surface due to repeating heat cycles during welding. Creep strain and creep rate within the HAZ adjacent to the weld metal zone were smaller than those within the base metal zone. Creep rate of the weld metal zone in the welded joint was smaller than that of the weld metal specimen due to the restraint of the hardened HAZ adjacent to the zone. The full-thickness welded joint specimens showed longer lives than weld metal specimens, though the lives of the latter was shorter than those of the base metal (undermatching). In the full-thickness welded joint specimen, crack started from the last pass layer of the weld metal zone and fracture occurred at the zone. From the results mentioned above, in order to evaluate the creep properties of the welded joint correctly, it is necessary to conduct the creep test using the full-thickness welded joint specimen which includes the weakest zones of the weld metal, the front and back sides of the plate. (author)

Guided-wave tomography imaging plate defects by laser-based ultrasonic techniques

Energy Technology Data Exchange (ETDEWEB)

Park, Jun Pil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Pusan (Korea, Republic of)

2014-12-15

Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

Prediction of retained residual stresses in laboratory fracture mechanics specimens extracted from welded components

International Nuclear Information System (INIS)

Hurlston, R.G.; Sherry, A.H.; James, P.; Sharples, J.K.

2015-01-01

The measurement of weld material fracture toughness properties is important for the structural integrity assessment of engineering components. However, welds can contain high levels of residual stress and these can be retained in fracture mechanics specimens, particularly when machined from non-stress relieved welds. Retained residual stresses can make the measurement of valid fracture toughness properties difficult. This paper describes the results of analytical work undertaken to investigate factors that can influence the magnitude and distribution of residual stresses retained in fracture mechanics specimen blanks extracted from as-welded ferritic and austenitic stainless steel plates. The results indicate that significant levels of residual stress can be retained in specimen blanks prior to notching, and that the magnitude and distribution of stress is dependent upon material properties, specimen geometry and size, and extraction location through the thickness of the weld. Finite element modelling is shown to provide a useful approach for estimating the level and distributions of retained residual stresses. A new stress partitioning approach has been developed to estimate retained stress levels and results compare favourably with FE analysis and available experimental data. The approach can help guide the selection of specimen geometry and machining strategies to minimise the level of residual stresses retained in fracture mechanics specimen blanks extracted from non stress-relieved welds and thus improve the measurement of weld fracture toughness properties. - Highlights: • A simplified method for generating realistic weld residual stresses has been developed. • It has been shown that significant levels of residual stress can be retained within laboratory fracture mechanics specimens. • The level and distribution is dependant upon material, specimen type, specimen size and extraction location. • A method has been developed to allow estimates of the

Consultation on urological specimens from referred cancer patients using real-time digital microscopy

DEFF Research Database (Denmark)

Holten-Rossing, Henrik; Larsen, Lise Grupe; Toft, Birgitte Grønkaer

2016-01-01

requirements. The aim was to evaluate whether real-time digital microscopy for urological cancer specimens during the primary diagnostic process can replace subsequent physical slide referral and reassessment without compromising diagnostic safety. METHODS: From May to October 2014, tissue specimens from 130...... Finetek) was employed. The Pathology Department at Næstved Hospital was equipped with a digital microscope and three consultant pathologists were stationed at Rigshospitalet with workstations optimized for digital microscopy. Representative slides for each case were selected for consultation and live...

Interference fit effect on holed single plates loaded with tension-tension stresses

Directory of Open Access Journals (Sweden)

D. Croccolo

2012-07-01

Full Text Available This paper deals with the influence of interference fit coupling on the fatigue strength of holed plates. The effect was investigated both experimentally and numerically. Axial fatigue tests have been carried out on holed specimens made of high performance steel (1075MPa of Ultimate strength and 990MPa of Yield strength with or without a pin, made of the same material, press fitted into their central hole. Three different conditions have been investigated: free hole specimens, specimens with 0.6% of nominal specific interference and specimens with 2% of nominal specific interference. The experimental stress-life (S–N curves pointed out an increased fatigue life of the interference fit specimens compared with the free hole ones. The numerical investigation was performed in order to analyse the stress fields by applying an elastic plastic 2D simulation with a commercial Finite Element software. The stress history and distribution along the contact interference of the fitted samples indicates a significant reduction of the local stress range due to the externally applied loading (remote stress since a residual and compressive stress field is generated by the pin insertion.

Fabrication of AA6061-T6 Plate Type Fuel Assembly Using Electron Beam Welding Process

International Nuclear Information System (INIS)

Kim, Soosung; Seo, Kyoungseok; Lee, Donbae; Park, Jongman; Lee, Yoonsang; Lee, Chongtak

2014-01-01

AA6061-T6 aluminum alloy is easily welded by conventional GTAW (Gas Tungsten Arc Welding), LBW (Laser Beam Welding) and EBW. However, certain characteristics, such as solidification cracking, porosity, HAZ (Heat-affected Zone) degradation must be considered during welding. Because of high energy density and low heat input, especially LBW and EBW processes possess the advantage of minimizing the fusing zone and HAZ and producing deeper penetration than arc welding processes. In present study, to apply for the nuclear fuel plate fabrication and assembly, a fundamental EBW experiment using AA6061-T6 aluminum alloy specimens was conducted. Furthermore, to establish the welding process, and satisfy the requirements of the weld quality, EBW apparatus using an electron welding gun and vacuum chamber was developed, and preliminary investigations for optimizing the welding parameters of the specimens using AA6061-T6 aluminum plates were also performed. The EB weld quality of AA6061-T6 aluminum alloy for the fuel plate assembly has been also studied by the shrinkage measurement and weld inspection using computed tomography. This study was carried out to determine the suitable welding parameters and to evaluate tensile strength of AA6061-T6 aluminum alloy. In the present experiment, satisfactory electron beam welding process of the full-sized sample was being developed. Based on this fundamental study, fabrication of the plate-type fuel assembly will be provided for the future Ki-Jang research reactor project

Use of precracked Charpy and smaller specimens to establish the master curve

International Nuclear Information System (INIS)

Sokolov, M.A.; McCabe, D.E.; Nanstad, R.K.; Davidov, Y.A.

1997-01-01

The current provisions used in the U.S. Code of Federal Regulations for the determination of the fracture toughness of reactor pressure vessel steels employs an assumption that there is a direct correlation between K Ic lower-bound toughness and the Charpy V-notch transition curve. Such correlations are subject to scatter from both approaches which weakens the reliability of fracture mechanics-based analyses. In this study, precracked Charpy and smaller size specimens are used in three-point static bend testing to develop fracture mechanics based K k values. The testing is performed under carefully controlled conditions such that the values can be used to predict the fracture toughness performance of large specimens. The concept of a universal transition curve (master curve) is applied. Data scatter that is characteristic of commercial grade steels and their weldments is handled by Weibull statistical modeling. The master curve is developed to describe the median K Jc fracture toughness for 1T size compact specimens. Size effects are modeled using weakest-link theory and are studied for different specimen geometries. It is shown that precracked Charpy specimens when tested within their confined validity limits follow the weakest-link size-adjustment trend and predict the fracture toughness of larger specimens. Specimens of smaller than Charpy sizes (5 mm thick) exhibit some disparities in results relative to weakest-link size adjustment prediction suggesting that application of such adjustment to very small specimens may have some limitations

Clinical evaluation of a mobile digital specimen radiography system for intraoperative specimen verification.

Science.gov (United States)

Wang, Yingbing; Ebuoma, Lilian; Saksena, Mansi; Liu, Bob; Specht, Michelle; Rafferty, Elizabeth

2014-08-01

Use of mobile digital specimen radiography systems expedites intraoperative verification of excised breast specimens. The purpose of this study was to evaluate the performance of a such a system for verifying targets. A retrospective review included 100 consecutive pairs of breast specimen radiographs. Specimens were imaged in the operating room with a mobile digital specimen radiography system and then with a conventional digital mammography system in the radiology department. Two expert reviewers independently scored each image for image quality on a 3-point scale and confidence in target visualization on a 5-point scale. A target was considered confidently verified only if both reviewers declared the target to be confidently detected. The 100 specimens contained a total of 174 targets, including 85 clips (49%), 53 calcifications (30%), 35 masses (20%), and one architectural distortion (1%). Although a significantly higher percentage of mobile digital specimen radiographs were considered poor quality by at least one reviewer (25%) compared with conventional digital mammograms (1%), 169 targets (97%), were confidently verified with mobile specimen radiography; 172 targets (98%) were verified with conventional digital mammography. Three faint masses were not confidently verified with mobile specimen radiography, and conventional digital mammography was needed for confirmation. One faint mass and one architectural distortion were not confidently verified with either method. Mobile digital specimen radiography allows high diagnostic confidence for verification of target excision in breast specimens across target types, despite lower image quality. Substituting this modality for conventional digital mammography can eliminate delays associated with specimen transport, potentially decreasing surgical duration and increasing operating room throughput.

Small specimen technique for assessing mechanical properties of metallic components

Energy Technology Data Exchange (ETDEWEB)

Lobo, Raquel M.; Andrade, Arnaldo H.P.; Morcelli, Aparecido E., E-mail: rmlobo@ipen.br, E-mail: morcelliae@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-11-01

Small Punch Test (SPT) is one of the most promising techniques of small specimen test, which was originally applied in testing of irradiated materials in nuclear engineering. Then it was introduced to other fields as an almost nondestructive method to measure the local mechanical properties that are difficult to be obtained using conventional mechanical tests. Most studies to date are focused on metallic materials, although SPT applications are recently spreading to other materials. The small punch test (SPT) employs small-sized specimens (for example, samples measuring 8 mm in diameter and 0.5 mm thick). The specimen is firmly clamped between two circular dies and is bi-axially strained until failure into a circular hole using a hemispherical punch. The 'load-punch displacement' record can be used to estimate the yield strength, the ultimate tensile strength, the tensile elongation, and the temperature of the ductile-to-brittle transition. Recently, some researchers are working on the use of miniature notched or pre-cracked specimens (denoted as p-SPT) to validate its geometry and dimensions for obtaining the fracture properties of metallic materials. In a first approach, the technique makes it possible to convert primary experimental data into conventional mechanical properties of a massive specimen. In this paper a comprehensive review of the different STP applications is presented with the aim of clarifying its usefulness. (author)

Small specimen technique for assessing mechanical properties of metallic components

International Nuclear Information System (INIS)

Lobo, Raquel M.; Andrade, Arnaldo H.P.; Morcelli, Aparecido E.

2017-01-01

Small Punch Test (SPT) is one of the most promising techniques of small specimen test, which was originally applied in testing of irradiated materials in nuclear engineering. Then it was introduced to other fields as an almost nondestructive method to measure the local mechanical properties that are difficult to be obtained using conventional mechanical tests. Most studies to date are focused on metallic materials, although SPT applications are recently spreading to other materials. The small punch test (SPT) employs small-sized specimens (for example, samples measuring 8 mm in diameter and 0.5 mm thick). The specimen is firmly clamped between two circular dies and is bi-axially strained until failure into a circular hole using a hemispherical punch. The 'load-punch displacement' record can be used to estimate the yield strength, the ultimate tensile strength, the tensile elongation, and the temperature of the ductile-to-brittle transition. Recently, some researchers are working on the use of miniature notched or pre-cracked specimens (denoted as p-SPT) to validate its geometry and dimensions for obtaining the fracture properties of metallic materials. In a first approach, the technique makes it possible to convert primary experimental data into conventional mechanical properties of a massive specimen. In this paper a comprehensive review of the different STP applications is presented with the aim of clarifying its usefulness. (author)

Experimental Study on Welded Headed Studs Used In Steel Plate-Concrete Composite Structures Compared with Contactless Method of Measuring Displacement

Science.gov (United States)

Kisała, Dawid; Tekieli, Marcin

2017-10-01

Steel plate-concrete composite structures are a new innovative design concept in which a thin steel plate is attached to the reinforced concrete beam by means of welded headed studs. The comparison between experimental studies and theoretical analysis of this type of structures shows that their behaviour is dependent on the load-slip relationship of the shear connectors used to ensure sufficient bond between the concrete and steel parts of the structure. The aim of this paper is to describe an experimental study on headed studs used in steel plate-concrete composite structures. Push-out tests were carried out to investigate the behaviour of shear connectors. The test specimens were prepared according to standard push-out tests, however, instead of I-beam, a steel plate 16 mm thick was used to better reflect the conditions in the real structure. The test specimens were produced in two batches using concrete with significantly different compressive strength. The experimental study was carried out on twelve specimens. Besides the traditional measurements based on LVDT sensors, optical measurements based on the digital image correlation method (DIC) and pattern tracking methods were used. DIC is a full-field contactless optical method for measuring displacements in experimental testing, based on the correlation of the digital images taken during test execution. With respect to conventional methods, optical measurements offer a wider scope of results and can give more information about the material or construction behaviour during the test. The ultimate load capacity and load-slip curves obtained from the experiments were compared with the values calculated based on Eurocodes, American and Chinese design specifications. It was observed that the use of the relationships developed for the traditional steel-concrete composite structures is justified in the case of ultimate load capacity of shear connectors in steel plate-concrete composite structures.

New specimen design for studying the growth of small fatigue cracks with surface acoustic waves

Science.gov (United States)

London, Blair

1985-08-01

The study of small surface fatigue cracks in AISI 4140 quenched and tempered steel by a nondestructive surface acoustic wave technique is summarized. A novel cantilevered bending, plate-type fatigue specimen is described that is compatible with the acoustic method. Small cracks are initiated from a 25-μm deep surface pit produced by an electrospark machine. The importance of studying these cracks which closely approximate naturally occurring fatigue cracks is briefly discussed.

Low velocity impact of 6082-T6 aluminum plates

Science.gov (United States)

Mocian, Oana Alexandra; Constantinescu, Dan Mihai; Sandu, Marin; Sorohan, Ştefan

2018-02-01

The low velocity domain covers vehicle impacts, ship collisions and even accidentally tool drops. Even though more and more research is needed into these fields, most of the papers concerning impact problems focus on impact at medium and high velocities. Understanding the behavior of structures subjected to low velocity impact is of major importance when referring to impact resistance and damage tolerance. The paper presents an experimental and numerical investigation on the low velocity behavior of 6082-T6 aluminum plates. Impact tests were performed using an Instron Ceast 9340 drop-weight testing machine. In the experimental procedure, square plates were mounted on a circular support, fixed with a pneumatic clamping system and impacted with a hemispherical steel projectile. Specimens were impacted at constant weight and different impact velocities. The effect of different impact energies was investigated. The impact event was then simulated using the nonlinear finite element code LS_DYNA in order to determine the effect of strain rate upon the mechanical behavior of the aluminum plates. Moreover, in order to capture the exact behavior of the material, a special attention has been given to the selection of the correct material model and its parameters, which, in large extent, depend on the observed behavior of the aluminum plate during the test and the actual response of the plate under simulation. The numerical predictions are compared with the experimental observations and the applicability of the numerical model for further researches is analyzed.

Modeling particulate removal in plate-plate and wire-plate electrostatic precipitators

Directory of Open Access Journals (Sweden)

S Ramechecandane

2016-09-01

Full Text Available The present study is concerned with the modeling of electrically charged particles in a model plate-plate and a single wire-plate electrostatic precipitator (ESP. The particle concentration distributions for both a plate-plate and a wire-plate ESP are calculated using a modified drift flux model. Numerical investigations are performed using the modified drift flux model for particle number concentration, in addition to the RNG k - ε model for the mean turbulent flow field and the Poisson equation for the electric field. The proposed model and the outlined methodology for coupling the flow field, electric field, charging kinetics and particle concentration is applied to two model precipitators that are truly representative of a wide class of commercialized ESPs. The present investigation is quite different from the earlier studies as it does not make assumptions like a homogeneous electric field or an infinite turbulent diffusivity. The electric field calculated is a strong function of position and controls the migration velocity of particles. Hence, the proposed model can be implemented in a flow solver to obtain a full-fledged solution for any kind of ESP with no limitations on the particle number concentration, as encountered in a Lagrangian approach. The effect of turbulent diffusivity on particle number concentration in a plate-plate ESP is investigated in detail and the results obtained are compared with available experimental data. Similarly, the effect of particle size/diameter and applied electric potential on the accumulative collection performance in the case of a wire-plate ESP is studied and the results obtained are compared with available numerical data. The numerical results obtained using the modified drift flux model for both the plate-plate and wire-plate ESP are in close agreement with available experimental and numerical data.

The coating layer structure of commercial chrome plates

International Nuclear Information System (INIS)

Chen, Sheng

2015-01-01

Highlights: • AES and XPS depth profiling analysis were used in the experiment. • The detailed coating layer structure of the commercial chrome plate was obtained. • Peak fitting method was used to investigate the chemical states of Cr in the coating. - Abstract: The surface and cross-sectional morphologies of the commercial chrome plate coating layer with the thickness of dozens of nanometers have been observed. To investigate the detailed structure of the coating layer, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) combined with the low energy Ar + sputtering technique have been employed. Through careful analysis of experimental data, it can be obtained that the coating layer of commercial chrome plates is composed of four layers from top to bottom with different compositions

Control of biofouling on titanium condenser tubes with the use of electroless copper plating

International Nuclear Information System (INIS)

Anandkumar, B.; George, R.P.; Kamachi Mudali, U.; Ramachandran, D.

2015-01-01

In sea water environments titanium condenser tubes face serious issues of biofouling and biomineralization. Electroless plating of nanocopper film is attempted inside the tubes for the control of biofilm formation. Using advanced techniques like AFM, SEM, and XPS, electroless copper plated flat Ti specimens were characterized. Examination of Cu coated Ti surfaces using AFM and SEM showed more reduction in the microroughness compared to anodized Ti surface. Cu 2p 3/2 peak in XPS spectral analysis showed the shift in binding energy inferring the reduction of the hydroxide to metallic copper. Tubular specimens were exposed to sea water up to three months and withdrawn at monthly intervals to evaluate antibacterial activity and long term stability of the coating. Total viable counts and epifluorescence microscopy analyses showed two orders decrease in bacterial counts on copper coated Ti specimens when compared to as polished control Ti specimens. Molecular biology techniques like DGGE and protein expression analysis system were done to get insight into the community diversity and copper tolerance of microorganisms. DGGE gel bands clearly showed the difference in the bacterial diversity inferring from the 16S rRNA gene fragments (V3 regions). Protein analysis showed distinct protein spots appearing in electroless copper coated Ti biofilm protein samples in addition to protein spots common to both the biofilms of Cu coated and as polished Ti. The results indicated copper accumulating proteins in copper resistant bacterial species of biofilm. Reduced microroughness of the surface and toxic copper ions resulted in good biofouling control even after three months exposure to sea water. (author)

Tensile Test of Welding Joint Parts for a Plate-type Fuel Assembly

Energy Technology Data Exchange (ETDEWEB)

Yoon, K. H.; Kim, J. Y.; Kim, H. J.; Yim, J. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

The tensile tests were performed using an INSTRON 4505 (universal tensile) testing machine. These welding joints are composed of two parts for the soundness of the fuel assembly; one is the side plate with a fixing bar and the other is a side plate with an end fitting. These two joint parts are fabricated by TIG welding method. The tensile tests of the welding joints of a plate-type FA are executed by a tensile test. The fixture configurations for the specimen are very important to obtain the strict test results. The maximum strength has an approximately linear correlation with the unit bonding length of the welding joints. In spite of these results, the maximum strengths of the welding joints are satisfied according to the minimum requirement. These tensile tests of the joint parts for a plate-type fuel assembly (FA) have to be executed to evaluate the structural strength. For the tensile test, the joint parts of a FA used in the test are made of aluminum alloy (Al6061-T6)

Tensile Test of Welding Joint Parts for a Plate-type Fuel Assembly

International Nuclear Information System (INIS)

Yoon, K. H.; Kim, J. Y.; Kim, H. J.; Yim, J. S.

2013-01-01

The tensile tests were performed using an INSTRON 4505 (universal tensile) testing machine. These welding joints are composed of two parts for the soundness of the fuel assembly; one is the side plate with a fixing bar and the other is a side plate with an end fitting. These two joint parts are fabricated by TIG welding method. The tensile tests of the welding joints of a plate-type FA are executed by a tensile test. The fixture configurations for the specimen are very important to obtain the strict test results. The maximum strength has an approximately linear correlation with the unit bonding length of the welding joints. In spite of these results, the maximum strengths of the welding joints are satisfied according to the minimum requirement. These tensile tests of the joint parts for a plate-type fuel assembly (FA) have to be executed to evaluate the structural strength. For the tensile test, the joint parts of a FA used in the test are made of aluminum alloy (Al6061-T6)

A crack arrest test using a toughness gradient steel plate

International Nuclear Information System (INIS)

Okamura, H.; Yagawa, G.; Urabe, Y.; Satoh, M.; Sano, J.

1995-01-01

Pressurized thermal shock (PTS) is a phenomenon that can occur in the reactor pressure vessels (RPVs) with internal pressure and is one of the most severe stress conditions that can be applied to the vessel. Preliminary research has shown that no PTS concern is likely to exist on Japanese RPVs during their design service lives. However, public acceptance of vessel integrity requires analyses and experiment in order to establish an analytical method and a database for life extension of Japanese RPVs. The Japanese PTS integrity study was carried out from FY 1983 to FY 1991 as a national project by Japan Power Engineering and Inspection Corporation (JAPEIC) under contract with Ministry of International Trade and Industry (MITI) in cooperation with LWR utilities and vendors. Here, a crack arrest test was carried out using a toughness gradient steel plate with three layers to study the concept of crack arrest toughness. Four-point bending load with thermal shock was applied to the large flat plate specimen with a surface crack. Five crack initiations and arrests were observed during the test and the propagated crack bifurcated. Finally, cracks were arrested at the boundary of the first and the second layer, except for a small segment of the crack. The first crack initiation took place slightly higher than the lower bound of K Ic data obtained by ITCT specimens. That is, the K IC concept for brittle crack initiation was verified for heavy section steel plates. The first crack arrest took place within the scatter band of K Ia and K Id data for the first layer. That is, the K Ia concept appears applicable for crack arrest of a short crack jump

Vibration analysis of orthotropic circular and elliptical nano-plates embedded in elastic medium based on nonlocal Mindlin plate theory and using Galerkin method

International Nuclear Information System (INIS)

Anjomshoa, Amin; Tahani, Masoud

2016-01-01

In the present study a continuum model based on the nonlocal elasticity theory is developed for free vibration analysis of embedded ortho tropic thick circular and elliptical nano-plates rested on an elastic foundation. The elastic foundation is considered to behave like a Pasternak type of foundations. Governing equations for vibrating nano-plate are derived according to the Mindlin plate theory in which the effects of shear deformations of nano-plate are also included. The Galerkin method is then employed to obtain the size dependent natural frequencies of nano-plate. The solution procedure considers the entire nano-plate as a single super-continuum element. Effect of nonlocal parameter, lengths of nano-plate, aspect ratio, mode number, material properties, thickness and foundation on circular frequencies are investigated. It is seen that the nonlocal frequencies of the nano-plate are smaller in comparison to those from the classical theory and this is more pronounced for small lengths and higher vibration modes. It is also found that as the aspect ratio increases or the nanoplate becomes more elliptical, the small scale effect on natural frequencies increases. Further, it is observed that the elastic foundation decreases the influence of nonlocal parameter on the results. Since the effect of shear deformations plays an important role in vibration analysis and design of nano-plates, by predicting smaller values for fundamental frequencies, the study of these nano-structures using thick plate theories such as Mindlin plate theory is essential.

Comparison of BR3 Surveillance and Vessel Plates to the Surrogate Plates Representative of the Yankee Rowe PWR Vessel

Energy Technology Data Exchange (ETDEWEB)

Fabry, A.; Chaouadi, R.; Puzzolante, J.L.; Van de Velde, J.; Biemiller, E.C.; Rosinski, S.T.; Carter, R.G

1998-07-01

The sister pressure vessels at the BR3 and Yankee Rowe PWR plants were operated at lower-than-usual temperature ( 260 degrees Celsius) and their plates were austenitized a higher-than-usual temperature (970 degrees Celsius) - a heat treatment leading to a coarser microstructure than is typical for the fine grain plates considered in development of USNRC Regulatory Guide 1.99. The surveillance programs provided by Westinghouse for the two plants were limited to the same A302-B plate representative of the Rowe vessel upper shell plate; this material displayed outlier behaviour characterized by a 41 J Charpy-V Notch shift significantly larger than predicted by Regulatory Guide 1.99. Because lower irradiation temperature and nickel alloying are generally considered detrimental to irradiation sensitivity, there was a major concern that the nickel-modified lower Rate plate and the nickel-modified BR3 plate may become too embrittled to satisfy the toughness requirements embodied in the PTS screening criterion. This paper compares free complementary studies undertaken to clarify these uncertainties: (1) The accelerated irradiation and test program launched in 1990 by Yankee Atomic Electric Company using typical vessel plate materials containing 0.24% copper at two nickel levels: YA1, 0.63 % (A533-B) and YA9, 0.19 (A302-B). These were heat-treated to produce the coarse and fine grain microstructures representative of the Yankee/BR3 and the Regulatory Guide plates, respectively; (2) The BR3 surveillance and vessel testing program: this vessel was wet-annealed in 1984, relicensed for operation till the plant shutdown in 1987, and was trepanned in early 1995; (3) The accelerated irradiations in the Belgian test reactor BR2 of the Yankee coarse grain plates YA1 and YA9 together with BR3 vessel specimens extracted at nozzle elevation, a location with negligible radiation exposure. It is contended that the PTS screening criterion was never attained by the BR3 and Rowe plates, and

Comparison of BR3 Surveillance and Vessel Plates to the Surrogate Plates Representative of the Yankee Rowe PWR Vessel

International Nuclear Information System (INIS)

Fabry, A.; Chaouadi, R.; Puzzolante, J.L.; Van de Velde, J.; Biemiller, E.C.; Rosinski, S.T.; Carter, R.G.

1998-07-01

The sister pressure vessels at the BR3 and Yankee Rowe PWR plants were operated at lower-than-usual temperature ( 260 degrees Celsius) and their plates were austenitized a higher-than-usual temperature (970 degrees Celsius) - a heat treatment leading to a coarser microstructure than is typical for the fine grain plates considered in development of USNRC Regulatory Guide 1.99. The surveillance programs provided by Westinghouse for the two plants were limited to the same A302-B plate representative of the Rowe vessel upper shell plate; this material displayed outlier behaviour characterized by a 41 J Charpy-V Notch shift significantly larger than predicted by Regulatory Guide 1.99. Because lower irradiation temperature and nickel alloying are generally considered detrimental to irradiation sensitivity, there was a major concern that the nickel-modified lower Rate plate and the nickel-modified BR3 plate may become too embrittled to satisfy the toughness requirements embodied in the PTS screening criterion. This paper compares free complementary studies undertaken to clarify these uncertainties: (1) The accelerated irradiation and test program launched in 1990 by Yankee Atomic Electric Company using typical vessel plate materials containing 0.24% copper at two nickel levels: YA1, 0.63 % (A533-B) and YA9, 0.19 (A302-B). These were heat-treated to produce the coarse and fine grain microstructures representative of the Yankee/BR3 and the Regulatory Guide plates, respectively; (2) The BR3 surveillance and vessel testing program: this vessel was wet-annealed in 1984, relicensed for operation till the plant shutdown in 1987, and was trepanned in early 1995; (3) The accelerated irradiations in the Belgian test reactor BR2 of the Yankee coarse grain plates YA1 and YA9 together with BR3 vessel specimens extracted at nozzle elevation, a location with negligible radiation exposure. It is contended that the PTS screening criterion was never attained by the BR3 and Rowe plates, and

Comparison of BR3 surveillance and vessel plates to the surrogate plates representative of the Yankee Rowe PWR vessel

International Nuclear Information System (INIS)

Fabry, A.; Chaouadi, R.; Puzzolante, J.L.; Van de Velde, J.; Biemiller, E.C.; Rosinski, S.T.; Carter, R.G.

1999-01-01

The sister pressure vessels at the BR3 and Yankee Rowe PWR plants were operated at lower-than-usual temperature (∼260 C) and their plates were austenitized at higher-than-usual temperature (∼970 C) -- a heat treatment leading to a coarser microstructure than is typical for the fine grain plates considered in development of USNRC Regulatory Guide 1.99. The surveillance programs provided by Westinghouse for the two plants were limited to the same A302-B plate representative of the Rowe vessel upper shell plate; this material displayed outlier behavior characterized by a 41J. Charpy-V Notch shift significantly larger than predicted by Regulatory Guide 1.99. Because lower irradiation temperature and nickel alloying are generally considered detrimental to irradiation sensitivity, there was a major concern that the nickel-modified lower Rowe plate and the nickel-modified BR3 plate may become too embrittled to satisfy the toughness requirements embodied in the PTS screening criterion. This paper compares three complementary studies undertaken to clarify these uncertainties: (1) The accelerated irradiation and test program launched in 1990 by Yankee Atomic Electric Company using typical vessel plate materials containing 0.24% copper at two nickel levels: YA1, 0.63% (A533-B) and YA9, 0.19% (A302-B). These were heat-treated to produce the coarse and fine grain microstructures representative of the Yankee/BR3 and the Regulatory Guide plates, respectively; (2) The BR3 surveillance and vessel testing program; this vessel was wet-annealed in 1984, relicensed for operation till the plant shutdown in 1987, and was trepanned in early 1995; (3) The accelerated irradiations in the Belgian test reactor BR2 of the Yankee coarse grain plates YA1 and YA9 together with BR3 vessel specimens extracted at nozzle elevation, a location with negligible radiation exposure. It is contended that the PTS screening criterion was never attained by the BR3 and Rowe plates, and that the BR3 vessel

Creep crack growth behaviour of an AISI 316 steel plate for fast reactor structures

International Nuclear Information System (INIS)

D'Angelo, D.; Regis, V.

1985-01-01

The paper presents and analyses creep crack growth data obtained at 550, 600 and 650 0 C in air with SENT and CT specimens on type 316 stainless steel plate for LMFBR applications. Crack initiation and crack growth are tentatively correlated to K, sigmasub(net) and J* taking into account the constraint conditions due to specimen geometry. The validity of these parameters is discussed following the concept of transition time from small scale creep at the crack tip to extensive creep within the ligament. Post exposure microstructural and fractographic investigations do evidence that grain deformation processes are mainly responsible for cavity evolution. (orig.)

A computed microtomography method for understanding epiphyseal growth plate fusion

Science.gov (United States)

Staines, Katherine A.; Madi, Kamel; Javaheri, Behzad; Lee, Peter D.; Pitsillides, Andrew A.

2017-12-01

The epiphyseal growth plate is a developmental region responsible for linear bone growth, in which chondrocytes undertake a tightly regulated series of biological processes. Concomitant with the cessation of growth and sexual maturation, the human growth plate undergoes progressive narrowing, and ultimately disappears. Despite the crucial role of this growth plate fusion ‘bridging’ event, the precise mechanisms by which it is governed are complex and yet to be established. Progress is likely hindered by the current methods for growth plate visualisation; these are invasive and largely rely on histological procedures. Here we describe our non-invasive method utilising synchrotron x-ray computed microtomography for the examination of growth plate bridging, which ultimately leads to its closure coincident with termination of further longitudinal bone growth. We then apply this method to a dataset obtained from a benchtop microcomputed tomography scanner to highlight its potential for wide usage. Furthermore, we conduct finite element modelling at the micron-scale to reveal the effects of growth plate bridging on local tissue mechanics. Employment of these 3D analyses of growth plate bone bridging is likely to advance our understanding of the physiological mechanisms that control growth plate fusion.

Accurate characterization of wafer bond toughness with the double cantilever specimen

Science.gov (United States)

Turner, Kevin T.; Spearing, S. Mark

2008-01-01

The displacement loaded double cantilever test, also referred to as the "Maszara test" and the "crack opening method" by the wafer bonding community, is a common technique used to evaluate the interface toughness or surface energy of direct wafer bonds. While the specimen is widely used, there has been a persistent question as to the accuracy of the method since the actual specimen geometry differs from the ideal beam geometry assumed in the expression used for data reduction. The effect of conducting the test on whole wafer pairs, in which the arms of cantilevers are wide plates rather than slender beams, is examined in this work using finite element analysis. A model is developed to predict the equilibrium shape of the crack front and to develop a corrected expression for calculating interface toughness from crack length measurements obtained in tests conducted on whole wafer pairs. The finite element model, which is validated through comparison to experiments, demonstrates that using the traditional beam theory-based expressions for data reduction can lead to errors of up to 25%.

Progress towards RF heated steady-state plasma operations on LHD by employing ICRF heating methods and improved divertor plates

International Nuclear Information System (INIS)

Kumazawa, R.; Mutoh, T.; Saito, K.

2008-10-01

A long pulse plasma discharge experiment was carried out using RF heating power in the Large Helical Device (LHD), a currentless magnetic confining system. Progress in long pulse operation is summarized since the 10th experimental campaign (2006). A scaling relation of the plasma duration time to the applied RF power has been derived from the experimental data so far collected. It indicates that there exists a critical divertor temperature and consequently a critical RF heating power P RFcrit =0.65 MW. The area on the graph of the duration time versus the RF heating power was extended over the scaling relation by replacing divertor plates with new ones with better heat conductivity. The cause of the plasma collapse at the end of the long pulse operation was found to be the penetration of metal impurities. Many thin flakes consisting of heavy metals and graphite in stratified layers were found on the divertor plates and it was thought that they were the cause of impurity metals penetrating into the plasma. In a simulation involving injecting a graphite-coated Fe pellet to the plasma it was found that 230 Eμm in the diameter of the Fe pellet sphere was the critical size which led the plasma to collapse. A mode-conversion heating method was examined in place of the minority ICRF heating which has been employed in almost all the long-pulse plasma discharges. It was found that this method was much better from the viewpoint of achieving uniformity of the plasma heat load to the divertors. It is expected that P RFcrit will be increased by using the mode-conversion heating method. (author)

Positron emission zone plate holography for particle tracking

Energy Technology Data Exchange (ETDEWEB)

Gundogdu, O. [University of Birmingham, School of Physics and Astronomy, Birmingham B15 2TT (United Kingdom)]. E-mail: o.gundogdu@surrey.ac.uk

2006-01-15

Positron Emission Particle Tracking (PEPT) is a powerful non-invasive technique that has been used extensively for tracking a single particle. In this paper, we present a study of zone plate holography method in order to track multiple particles, mainly two particles. The main aim is to use as small number of events as possible in the order to make it possible to track particles in fast moving industrial systems. A zone plate with 100% focal efficiency is simulated and applied to the Positron Emission Tomography (PET) data for multiple particle tracking. A simple trajectory code was employed to explore the effects of the nature of the experimental trajectories. A computer holographic reconstruction code that simulates optical reconstruction was developed. The different aspects of the particle location, particle activity ratios for enabling tagging of particles and zone plate and hologram locations are investigated. The effect of the shot noise is investigated and the limitations of the zone plate holography are reported.

Positron emission zone plate holography for particle tracking

International Nuclear Information System (INIS)

Gundogdu, O.

2006-01-01

Positron Emission Particle Tracking (PEPT) is a powerful non-invasive technique that has been used extensively for tracking a single particle. In this paper, we present a study of zone plate holography method in order to track multiple particles, mainly two particles. The main aim is to use as small number of events as possible in the order to make it possible to track particles in fast moving industrial systems. A zone plate with 100% focal efficiency is simulated and applied to the Positron Emission Tomography (PET) data for multiple particle tracking. A simple trajectory code was employed to explore the effects of the nature of the experimental trajectories. A computer holographic reconstruction code that simulates optical reconstruction was developed. The different aspects of the particle location, particle activity ratios for enabling tagging of particles and zone plate and hologram locations are investigated. The effect of the shot noise is investigated and the limitations of the zone plate holography are reported

Strength characterization of tubular ceramic materials by flexure of semi-cylindrical specimens

DEFF Research Database (Denmark)

Kwok, Kawai; Kiesel, Lutz; Frandsen, Henrik Lund

2014-01-01

Mechanical strength at elevated temperatures and operating atmospheres needs to be characterized during development of tubular ceramic components for advanced energy technologies. Typical procedures are time-consuming because a large number of tests are required for a reliable statistical strength...... characterization and every specimen has to be subjected to the process conditions individually. This paper presents an efficient strength characterization methodology for tubular ceramics. The methodology employs flexure of semi-cylindrical specimens as the strength test and implements the tests within a facility...... conducted on oxygen transport membrane materials at room temperature and 850°C....

Guided-wave tomographic imaging of plate defects by laser-based ultrasonic techniques

Energy Technology Data Exchange (ETDEWEB)

Park, Junpil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of)

2016-12-15

Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

Radioactivity distribution measurement of various natural material surfaces with imaging plate

International Nuclear Information System (INIS)

Mori, C.; Suzuki, T.; Koido, S.; Uritani, A.; Yanagida, K.; Wu, Y.; Nishizawa, K.

1996-01-01

Distribution images of natural radioactivity in natural materials such as vegetables were obtained by using Imaging Platc. In ssuch cases, it is necessary to reduce background radiation intensity by one order or more. Graded shielding is very important. Espacially, the innermost surface of a shielding box sshould be covered with acrylic rein plate. We obtained natural radioactivity distribution images of vegetable, sea food, mea etc. Most β-rays emitted from 40 K print the radioactivity distribution image. Comparison between γ-ray intensity of KCL solution measured with HPGe detector and that of natural material specimen gave the radioactivity around 0.06- 0.04Bq/g depending on the kind and the part of specimens. (author). 6 refs., 5 figs., 1 tab

Conclusions regarding fracture mechanics testing and evaluation of small specimens - As evidenced by the finnish contribution to the IAEA CRP3 programme

Energy Technology Data Exchange (ETDEWEB)

Wallin, K; Valo, M; Rintamaa, R; Torronen, K [Technical Research Centre of Finland, Espoo (Finland); Ahlstrand, R [Imatran Voima Oy (IVO), Helsinki (Finland)

1994-12-31

An extensive mechanical property evaluation has been carried out on various specimens (a Japanese steel plate (JRQ), a French forging material (FFA) and a Japanese forging material (JFL)) in the as-received and irradiated conditions. The mechanical properties measured at different temperatures include Charpy-V notch and instrumented pre-cracked Charpy data and static and dynamic elastic-plastic fracture toughness based on the J-integral, with various specimen size and geometry. Test analysis lead to conclusions regarding the use of small specimen fracture mechanical tests for investigating irradiation effects: CVN{sub pc} and RCT type specimens are suitable for determining the materials fracture toughness even in the ductile/brittle transition region provided the elastic-plastic parameter K{sub JC} is applied together with a statistical size correction. These two specimen types yield equivalent results for the fracture toughness transition shift. Charpy-V appears not to be suitable for estimating the static fracture toughness transition shift. 8 refs., 11 figs.

Full size U-10Mo monolithic fuel foil and fuel plate fabrication-technology development

International Nuclear Information System (INIS)

Moore, G.A.; Jue, J-F.; Rabin, B.H.; Nilles, M.J.

2010-01-01

Full-size U-10Mo foils are being developed for use in high density LEU monolithic fuel plates. The application of a zirconium barrier layer to the foil is performed using a hot co-rolling process. Aluminium clad fuel plates are fabricated using Hot Isostatic Pressing (HIP) or a Friction Bonding (FB) process. An overview is provided of ongoing technology development activities, including: the co-rolling process, foil shearing/slitting and polishing, cladding bonding processes, plate forming, plate-assembly swaging, and fuel plate characterization. Characterization techniques being employed include, Ultrasonic Testing (UT), radiography, and microscopy. (author)

AN ELECTROPLATING METHOD OF FORMING PLATINGS OF NICKEL, COBALT, NICKEL ALLOYS OR COBALT ALLOYS

DEFF Research Database (Denmark)

1997-01-01

An electroplating method of forming platings of nickel, cobalt, nickel alloys or cobalt alloys with reduced stresses in an electrodepositing bath of the type: Watt's bath, chloride bath or a combination thereof, by employing pulse plating with periodic reverse pulse and a sulfonated naphthalene...

Transitional behaviour of thickness effects in shipbuilding materials (MS plate)

Science.gov (United States)

Mahmud, S. M. Ikhtiar; Razib, Amirul Hasan; Rahman, Md. Rabab Raiyatur

2017-12-01

Majority of the crack propagation in ships and offshore structures are caused due to fatigue. Previously, it was known that fatigue strength of notched specimen is dependent on size, but recently it came to light that fatigue strength of some welded joints depends on the thickness. Much investigation is done on the fatigue growth of welded joints. Fatigue often results in fracture accidents, which starts from the sites of structural discontinuities because of the reason that they may induce local stress concentrations. Structural discontinuities include notches, holes, sharp corners, and weld defects. Weld defects include undercut, porosity, lack of fusion, slag inclusion, incomplete weld root penetration, and misalignments. In order to investigate the effects of plate thickness on fatigue strength, semi-elliptical side notches (U and V shaped) in plates are studied in the present research. First consider a simple problem of crack emanating from notches in plates where the solution of stress intensity factor is given by an empirical formula so that the thickness effect on fatigue strength can easily be investigated for a variety of geometrical parameters. The present study aims to investigate the transitional behaviour of thickness effect in plates on fatigue strength. In order to calculate the stress, finite element analysis is carried by using ANSYS.

Nonlinear analysis of piezoelectric nanocomposite energy harvesting plates

International Nuclear Information System (INIS)

Rafiee, M; He, X Q; Liew, K M

2014-01-01

This paper investigates the nonlinear analysis of energy harvesting from piezoelectric functionally graded carbon nanotube reinforced composite plates under combined thermal and mechanical loadings. The excitation, which derives from harmonically varying mechanical in-plane loading, results in parametric excitation. The governing equations of the piezoelectric functionally graded carbon nanotube reinforced composite plates are derived based on classical plate theory and von Kármán geometric nonlinearity. The material properties of the nanocomposite plate are assumed to be graded in the thickness direction. The single-walled carbon nanotubes (SWCNTs) are assumed to be aligned, straight and have a uniform layout. The linear buckling and vibration behavior of the nanocomposite plates is obtained in the first step. Then, Galerkin’s method is employed to derive the nonlinear governing equations of the problem with cubic nonlinearities associated with mid-plane stretching. Periodic solutions are determined by using the Poincaré–Lindstedt perturbation scheme with movable simply supported boundary conditions. The effects of temperature change, the volume fraction and the distribution pattern of the SWCNTs on the parametric resonance, in particular the amplitude of vibration and the average harvested power of the smart functionally graded carbon nanotube reinforced composite plates, are investigated through a detailed parametric study. (paper)

Measurement and prediction of residual stress in a bead-on-plate weld benchmark specimen

International Nuclear Information System (INIS)

Ficquet, X.; Smith, D.J.; Truman, C.E.; Kingston, E.J.; Dennis, R.J.

2009-01-01

This paper presents measurements and predictions of the residual stresses generated by laying a single weld bead on a flat, austenitic stainless steel plate. The residual stress field that is created is strongly three-dimensional and is considered representative of that found in a repair weld. Through-thickness measurements are made using the deep hole drilling technique, and near-surface measurements are made using incremental centre hole drilling. Measurements are compared to predictions at the same locations made using finite element analysis incorporating an advanced, non-linear kinematic hardening model. The work was conducted as part of an European round robin exercise, coordinated as part of the NeT network. Overall, there was broad agreement between measurements and predictions, but there were notable differences

Thermoelastic wave propagation in laminated composites plates

Directory of Open Access Journals (Sweden)

Verma K. L.

2012-12-01

Full Text Available The dispersion of thermoelastic waves propagation in an arbitrary direction in laminated composites plates is studied in the framework of generalized thermoelasticity in this article. Three dimensional field equations of thermoelasticity with relaxation times are considered. Characteristic equation is obtained on employing the continuity of displacements, temperature, stresses and thermal gradient at the layers’ interfaces. Some important particular cases such as of free waves on reducing plates to single layer and the surface waves when thickness tends to infinity are also discussed. Uncoupled and coupled thermoelasticity are the particular cases of the obtained results. Numerical results are also obtained and represented graphically.

Investigation into the effects of steel wire rope specimen length on breaking force

CSIR Research Space (South Africa)

O'Brien, TM

2004-03-01

Full Text Available (2000). The methodology employed was to test different length of triangular strand and non-spin rope to destruction, and to evaluate these results against SABS 0293:1996. For each rope construction, specimens were prepared both with and without cut wires...

Vibration analysis of partially cracked plate submerged in fluid

Science.gov (United States)

Soni, Shashank; Jain, N. K.; Joshi, P. V.

2018-01-01

The present work proposes an analytical model for vibration analysis of partially cracked rectangular plates coupled with fluid medium. The governing equation of motion for the isotropic plate based on the classical plate theory is modified to accommodate a part through continuous line crack according to simplified line spring model. The influence of surrounding fluid medium is incorporated in the governing equation in the form of inertia effects based on velocity potential function and Bernoulli's equations. Both partially and totally submerged plate configurations are considered. The governing equation also considers the in-plane stretching due to lateral deflection in the form of in-plane forces which introduces geometric non-linearity into the system. The fundamental frequencies are evaluated by expressing the lateral deflection in terms of modal functions. The assessment of the present results is carried out for intact submerged plate as to the best of the author's knowledge the literature lacks in analytical results for submerged cracked plates. New results for fundamental frequencies are presented as affected by crack length, fluid level, fluid density and immersed depth of plate. By employing the method of multiple scales, the frequency response and peak amplitude of the cracked structure is analyzed. The non-linear frequency response curves show the phenomenon of bending hardening or softening and the effect of fluid dynamic pressure on the response of the cracked plate.

49 CFR 40.173 - Who is responsible for paying for the test of a split specimen?

Science.gov (United States)

2010-10-01

... is responsible for paying for the test of a split specimen? (a) As the employer, you are responsible... 49 Transportation 1 2010-10-01 2010-10-01 false Who is responsible for paying for the test of a.... (b) As the employer, you must not condition your compliance with these requirements on the employee's...

Hydrodynamics of a flexible plate between pitching rigid plates

Science.gov (United States)

Kim, Junyoung; Kim, Daegyoum

2017-11-01

The dynamics of a flexible plate have been studied as a model problem in swimming and flying of animals and fluid-structure interaction of plants and flags. Motivated by fish schooling and an array of sea grasses, we investigate the dynamics of a flexible plate closely placed between two pitching rigid plates. In most studies on passive deformation of the flexible plate, the plate is immersed in a uniform flow or a wavy flow. However, in this study, the flexible plate experiences periodic deformation by the oscillatory flow generated by the prescribed pitching motion of the rigid plates. In our model, the pitching axes of the rigid plates and the clamping position of the flexible plate are aligned on the same line. The flexible plate shows various responses depending on length and pitching frequency of rigid plates, thickness of a flexible plate, and free-stream velocity. To find the effect of each variable on the response of the flexible plate, amplitude of a trailing edge and modal contribution of a flapping motion are compared, and flow structure around the flexible plate is examined.

Detection, mapping, and quantification of single walled carbon nanotubes in histological specimens with photoacoustic microscopy.

Science.gov (United States)

Avti, Pramod K; Hu, Song; Favazza, Christopher; Mikos, Antonios G; Jansen, John A; Shroyer, Kenneth R; Wang, Lihong V; Sitharaman, Balaji

2012-01-01

In the present study, the efficacy of multi-scale photoacoustic microscopy (PAM) was investigated to detect, map, and quantify trace amounts [nanograms (ng) to micrograms (µg)] of SWCNTs in a variety of histological tissue specimens consisting of cancer and benign tissue biopsies (histological specimens from implanted tissue engineering scaffolds). Optical-resolution (OR) and acoustic-resolution (AR)--Photoacoustic microscopy (PAM) was employed to detect, map and quantify the SWCNTs in a variety of tissue histological specimens and compared with other optical techniques (bright-field optical microscopy, Raman microscopy, near infrared (NIR) fluorescence microscopy). Both optical-resolution and acoustic-resolution PAM, allow the detection and quantification of SWCNTs in histological specimens with scalable spatial resolution and depth penetration. The noise-equivalent detection sensitivity to SWCNTs in the specimens was calculated to be as low as ∼7 pg. Image processing analysis further allowed the mapping, distribution, and quantification of the SWCNTs in the histological sections. The results demonstrate the potential of PAM as a promising imaging technique to detect, map, and quantify SWCNTs in histological specimens, and could complement the capabilities of current optical and electron microscopy techniques in the analysis of histological specimens containing SWCNTs.

Detection, mapping, and quantification of single walled carbon nanotubes in histological specimens with photoacoustic microscopy.

Directory of Open Access Journals (Sweden)

Pramod K Avti

Full Text Available In the present study, the efficacy of multi-scale photoacoustic microscopy (PAM was investigated to detect, map, and quantify trace amounts [nanograms (ng to micrograms (µg] of SWCNTs in a variety of histological tissue specimens consisting of cancer and benign tissue biopsies (histological specimens from implanted tissue engineering scaffolds.Optical-resolution (OR and acoustic-resolution (AR--Photoacoustic microscopy (PAM was employed to detect, map and quantify the SWCNTs in a variety of tissue histological specimens and compared with other optical techniques (bright-field optical microscopy, Raman microscopy, near infrared (NIR fluorescence microscopy.Both optical-resolution and acoustic-resolution PAM, allow the detection and quantification of SWCNTs in histological specimens with scalable spatial resolution and depth penetration. The noise-equivalent detection sensitivity to SWCNTs in the specimens was calculated to be as low as ∼7 pg. Image processing analysis further allowed the mapping, distribution, and quantification of the SWCNTs in the histological sections.The results demonstrate the potential of PAM as a promising imaging technique to detect, map, and quantify SWCNTs in histological specimens, and could complement the capabilities of current optical and electron microscopy techniques in the analysis of histological specimens containing SWCNTs.

Viscoelastic Plate Analysis Based on Gâteaux Differential

Directory of Open Access Journals (Sweden)

Kadıoğlu Fethi

2016-01-01

Full Text Available In this study, it is aimed to analyze the quasi-static response of viscoelastic Kirchhoff plates with mixed finite element formulation based on the Gâteaux differential. Although the static response of elastic plate, beam and shell structures is a widely studied topic, there are few studies that exist in the literature pertaining to the analysis of the viscoelastic structural elements especially with complex geometries, loading conditions and constitutive relations. The developed mixed finite element model in transformed Laplace-Carson space has four unknowns as displacement, bending and twisting moments in addition to the dynamic and geometric boundary condition terms. Four-parameter solid model is employed for modelling the viscoelastic behaviour. For transformation of the solutions obtained in the Laplace-Carson domain to the time domain, different numerical inverse transform techniques are employed. The developed solution technique is applied to several quasi-static example problems for the verification of the suggested numerical procedure.

Buckling and postbuckling behavior of square compression-loaded graphite-epoxy plates with circular cutouts

Science.gov (United States)

Nemeth, Michael P.

1990-01-01

Results are presented for unidirectional (0, 10)(sub s) and (90,10)(sub s) plates, ((0/90)(sub 5)(sub s)) plates, and for aluminum plates. Results are also presented for ((+/- theta)(sub 6)(sub s)) angle-ply plates for values of theta = 30, 45, and 60 degrees. The results indicate that the change in axial stiffness of a plate at buckling is strongly dependent upon cutout size and plate orthotropy. The presence of a cutout gives rise to an internal load distribution that changes, sometimes dramatically, as a function of cutout size coupled with the plate orthotropy. In the buckled state, the role of orthotropy becomes more significant since bending in addition to membrane orthotropy is present. Most of the plates with cutouts exhibited less postbuckling stiffness than the corresponding plate without a cutout, and the postbuckling stiffness decreased with increasing cutout size. However, some of the highly orthotropic plates with cutouts exhibited more postbuckling stiffness than the corresponding plate without a cutout. These results suggest the possibility of tailoring the cutout size and the stacking sequence of a composite plate to optimize postbuckling stiffness. It was found that plates with large radius cutouts do exhibit some postbuckling strength. The results also indicate that a cutout can influence modal interaction in a plate. Specifically, results are presented that show a plate with a relatively small cutout buckling at a higher load than the corresponding plate without a cutout, due to modal interaction. Other results are presented that indicate the presence of nonlinear prebuckling deformations, due to material nonlinearity, in the angle-ply plates with theta = 45 and 60 degrees. The nonlinear prebuckling deformations are more pronounced in the plates with theta = 45 degrees and become even more pronounced as the cutout size increases. Results are also presented that show how load-path eccentricity due to improper machining of the test specimens

Application of generalized function to dynamic analysis of elasto-plastic thick plates

International Nuclear Information System (INIS)

Zheng, D.; Weng, Z.

1987-01-01

The elasto-plastic dynamic analysis of thick plates is of great significance to the research and the design on an anti-seismic structure and an anti-explosive structure. In this paper, the derivative of δ-function is handled by using the generalized function. The dynamic influence coefficient of thick plates in deduced. A dynamic response of elasto-plastic thick plates its material has hardening behaviour considered, is analysed by using known elastic solutions. The general expressions for the dynamic response of elasto-plastic rectangular thick plates subjected arbitrary loads are given. Detailed computations are performed for the square plates of various height-span ratios. The results are compared with those obtained from the improved theory and the classical theory of plates. The modification of the classical deflection theory for plates is employed. The increment analysis is used for calculations. The yield function is considered as a function of inplane and transverse shear stresses. (orig./GL)

16 CFR Figure 3 to Part 1610 - Specimen Holder Supported in Specimen Rack

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Specimen Holder Supported in Specimen Rack 3 Figure 3 to Part 1610 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FLAMMABLE FABRICS ACT... Holder Supported in Specimen Rack ER25MR08.002 ...

Prediction of residual stresses in electron beam welded Ti-6Al-4V plates

Energy Technology Data Exchange (ETDEWEB)

Xu, Lianyong; Ge, Keke; Jing, Hongyang; Zhao, Lei; Lv, Xiaoqing [Tianjin Univ. (China); Han, Yongdian [Tianjin Univ. (China). Key Lab. of Advanced Joining Technology

2017-05-01

A thermo-metallurgical procedure based on the SYSWELD code was developed to predict welding temperature field, microstructure and residual stress in butt-welded Ti-6Al-4V plate taking into account phase transformation. The formation of martensite was confirmed by the CCT diagram and microstructure in the weld joint, which significantly affects the magnitude of residual stress. The hole drilling procedure was utilized to measure the values of residual stress at the top surface of the specimen, which are in well agreement with the numerical results. Both simulated and test results show that the magnitude and distribution of residual stress on the surface of the plate present a large gradient feature from the weld joint to the base metal. Moreover, the distribution law of residual stresses in the plate thickness was further analyzed for better understanding of its generation and evolution.

Surface flatness measurement of quasi-parallel plates employing three-beam interference with strong reference beam

Science.gov (United States)

Sunderland, Zofia; Patorski, Krzysztof

2016-12-01

A big challenge for standard interferogram analysis methods such as Temporal Phase Shifting or Fourier Transform is a parasitic set of fringes which might occur in the analyzed fringe pattern intensity distribution. It is encountered, for example, when transparent glass plates with quasi-parallel surfaces are tested in Fizeau or Twyman-Green interferometers. Besides the beams reflected from the plate front surface and the interferometer reference the beam reflected from the plate rear surface also plays important role; its amplitude is comparable with the amplitude of other beams. In result we face three families of fringes of high contrast which cannot be easily separated. Earlier we proposed a competitive solution for flatness measurements which relies on eliminating one of those fringe sets from the three-beam interferogram and separating two remaining ones with the use of 2D Continuous Wavelet Transform. In this work we cover the case when the intensity of the reference beam is significantly higher than the intensities of two object beams. The main advantage of differentiating beam intensities is the change in contrast of individual fringe families. Processing of such three-beam interferograms is modified but also takes advantage of 2D CWT. We show how to implement this method in Twyman-Green and Fizeau setups and compare this processing path and measurement procedures with previously proposed solutions.

The fatigue life and fatigue crack through thickness behavior of a surface cracked plate, 2

International Nuclear Information System (INIS)

Nam, Ki-Woo; Fujibayashi, Shinpei; Ando, Kotoji; Ogura, Nobukazu.

1987-01-01

Most structures have a region where stresses concentrate, and the probability of fatigue crack initiation may be higher than in other parts. Therefore, to improve the reliability of an LBB design, it is necessary to evaluate the growth and through thickness behavior of fatigue cracks in the stress concentration part. In this paper, a fatigue crack growth test at a stress concentration region has been made on 3 % NiCrMo and HT 80 steel. Stress concentration is caused by a fillet on the plate. The main results obtained are as follows : (1) Before cracking through the plate thickness, stress concentration has a remarkable effect on the fatigue crack growth behavior and it flatens the shape of a surface crack. The crack growth behavior can be explained quantatively by using the Newman-Raju equation and the stress resolving method proposed by ASME B and P Code SecXI. (2) The da/dN-ΔK relation obtained in a stress concentration specimen shows good agreement with that obtained in a surface cracked smooth specimen. (3) It is shown that stress concentration caused by a fillet has little effect on the crack growth rate after cracking through the plate thickness. (4) By using the K value based on eq. (1), (2), particular crack growth behavior and the change in crack shape after cracking through thickness can be explained quantatively. (author)

Sequencing historical specimens: successful preparation of small specimens with low amounts of degraded DNA.

Science.gov (United States)

Sproul, John S; Maddison, David R

2017-11-01

Despite advances that allow DNA sequencing of old museum specimens, sequencing small-bodied, historical specimens can be challenging and unreliable as many contain only small amounts of fragmented DNA. Dependable methods to sequence such specimens are especially critical if the specimens are unique. We attempt to sequence small-bodied (3-6 mm) historical specimens (including nomenclatural types) of beetles that have been housed, dried, in museums for 58-159 years, and for which few or no suitable replacement specimens exist. To better understand ideal approaches of sample preparation and produce preparation guidelines, we compared different library preparation protocols using low amounts of input DNA (1-10 ng). We also explored low-cost optimizations designed to improve library preparation efficiency and sequencing success of historical specimens with minimal DNA, such as enzymatic repair of DNA. We report successful sample preparation and sequencing for all historical specimens despite our low-input DNA approach. We provide a list of guidelines related to DNA repair, bead handling, reducing adapter dimers and library amplification. We present these guidelines to facilitate more economical use of valuable DNA and enable more consistent results in projects that aim to sequence challenging, irreplaceable historical specimens. © 2017 John Wiley & Sons Ltd.

Evaluation on ductile tearing properties of girth weld pipelines using SE(T) and SE(B) specimens

Energy Technology Data Exchange (ETDEWEB)

Mathias, Leonardo Luiz Siqueira; Ruggieri, Claudio [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Naval e Oceanica

2012-07-01

Predictive methodologies aimed at quantifying the impact of defects in oil and gas pipelines play a key role in safety assessment procedures of in-service facilities. Current methodologies for structural integrity assessments advocate the use of geometry dependent resistance curves so that crack-tip constraint in the test specimen closely matches the crack tip constraint for the structural component. Testing standards now under development to measure fracture resistance of pipeline steels (J and CTOD) most often employ single edge notched specimens under tension (SENT) to match a postulated defect in the structural component. This paper presents an investigation of the ductile tearing properties for a girth weld of an API 5L X80 pipeline steel using experimentally measured crack growth resistance curves (J-R curves). Testing of the girth weld pipeline steels employed side-grooved, clamped SE(T) specimen with center-crack weld and side-grooved, three-point bending SE(B) (or SENB) specimens to determine the J-R curves. The methods were compared in terms of geometry, relative crack size and crack-tip constraint, and the results were applied to a case study, to evaluate the degree of conservativeness in defect acceptance criteria. The tests involving SE(B) specimens are usually considered conservative, however, the comparison between this two methods may point an accurate alternative for girth weld assessments, since adequate geometry is adopted to describe accurately the structure's behavior. (author)

Optimum development temperature and duration for nuclear plate

International Nuclear Information System (INIS)

Nagoshi, Chieko.

1975-01-01

Sakura 100 μm thick nuclear plates have been employed to determine optimum temperature and duration of the Amidol developer for low energy protons (Ep 0 C were tried for periods of 15--35 min. For Ep 0 C and for development time less than 30 min. (auth.)

Vibration of functionally graded plate resting on viscoelastic elastic foundation subjected to moving loads

Science.gov (United States)

Duy Hien, Ta; Lam, Nguyen Ngoc

2018-04-01

The dynamics of plates subjected to a moving load must be considered by engineering mechanics and design structures. This paper deals with the dynamic responses of functionally graded (FG) rectangular plates resting on a viscoelastic foundation under moving loads. It is assumed that material properties of the plate vary continuously in the thickness direction according to the power-law. The governing equations are derived by using Hamilton’s principle, which considers the effect of the higher-order shear deformation in the plate. Transient responses of simply supported FG rectangular plates are employed by using state-space methods. Several examples are given for displacement and stresses in the plates with various structural parameters, and the effects of these parameters are discussed.

Development of an SH Wave Magnetostrictive Transducer Module for Guided Wave Testing of Plate Structures

International Nuclear Information System (INIS)

Cho, Seung Hyun; Park, Jae Ha; Kwon Hyu Sang; Ahn, Bong Young; Lee, Seung Seok

2009-01-01

Recently much attention has been paid to a guided wave due to its effective applicability to long range and fast inspection of structures. In guided wave based NDE, the appropriate selection of wave modes is one of important factors since the test performance is highly dependent on which mode of guided waves is employed. As far as plate-like structures are concerned, so far, SH guided wave has not been frequently applied compared to Lamb waves, which is mostly caused by the lack of proper and convenient transducers to generate and measure the SH waves. In this investigation, a new small-sized SH guided wave transducer based on magnetostriction is proposed. The present transducer was designed to be modular and be used with shear couplant to avoid the inconvenience of the existing magnetostrictive patch transducers, which comprises the ferromagnetic patch tightly bonded to a structure. The wave transduction mechanism and the detailed configuration of the present transducer are presented. Experimental verification is also conducted on test specimens and the results confirm the good performance of the present transducer module

Development of an SH Wave Magnetostrictive Transducer Module for Guided Wave Testing of Plate Structures

Energy Technology Data Exchange (ETDEWEB)

Cho, Seung Hyun; Park, Jae Ha; Kwon Hyu Sang; Ahn, Bong Young; Lee, Seung Seok [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

2009-04-15

Recently much attention has been paid to a guided wave due to its effective applicability to long range and fast inspection of structures. In guided wave based NDE, the appropriate selection of wave modes is one of important factors since the test performance is highly dependent on which mode of guided waves is employed. As far as plate-like structures are concerned, so far, SH guided wave has not been frequently applied compared to Lamb waves, which is mostly caused by the lack of proper and convenient transducers to generate and measure the SH waves. In this investigation, a new small-sized SH guided wave transducer based on magnetostriction is proposed. The present transducer was designed to be modular and be used with shear couplant to avoid the inconvenience of the existing magnetostrictive patch transducers, which comprises the ferromagnetic patch tightly bonded to a structure. The wave transduction mechanism and the detailed configuration of the present transducer are presented. Experimental verification is also conducted on test specimens and the results confirm the good performance of the present transducer module

A J Integral Approach for Measuring Cohesive Laws Using a Modified DCB Sandwich Specimen

DEFF Research Database (Denmark)

Lundsgaard-Larsen, Christian; Berggreen, Christian; Sørensen, Bent F.

2007-01-01

mode mixities. The sandwich specimen consists of glass fiber faces and Divinycell H200 foam core. Arbitrary stiffening of the sandwich specimen with steel bars adhered to the faces reduces rotations and ensures that the method is useable for a wide range of materials. The J integral is employed...... and the opening of the pre-crack tip is recorded by a commercial digital photogrammetry measurement system. Cohesive laws are extracted by differentiating J with respect to the normal and tangential opening of the pre-crack tip. Some results are presented and discussed....

Minimally invasive percutaneous plate fixation of distal tibia fractures.

LENUS (Irish Health Repository)

Bahari, Syah

2007-10-01

We report a series of 42 patients reviewed at a mean of 19.6 months after treatment of distal tibial and pilon fractures using the AO distal tibia locking plate with a minimally invasive percutaneous plate osteosynthesis (MIPPO) technique. Mean time to union was 22.4 weeks. All fractures united with acceptable alignment and angulation. Two cases of superficial infection were noted, with one case of deep infection. Mean SF36 score was 85 and mean AOFAS score was 90 at a mean of 19 months follow-up. We report satisfactory outcomes with the use of the AO distal tibia locking plate in treatment of unstable distal tibial fractures. Eighty-nine percent of the patients felt that they were back to their pre injury status and 95% back to their previous employment.

Numerical and Experimental Low-Velocity Impact Behaivor of Sandwich Plates with Viscoelastic Core

Directory of Open Access Journals (Sweden)

Soroush Sadeghnejad

2016-03-01

Full Text Available A numerical and experimental low-velocity impact behavior of sandwich plates have been presently studied with regard to the compressibility and viscoelasticity features of their cores. Face sheets were assumed to be anisotropic composites or isotropic aluminum materials and a viscoelastic behavior has been considered for core. The boundary conditions are assumed to be simply supported or rigid. Abaqus, as FEM software, and its python script programming feature, have been used to model the specimens. To model hyper-viscoelastic nonlinear behavior of the core, Ogden hyper-foam elasticity and Prony series approach are manipulated. To solve the numerical problem, dynamic explicit solver option with sufficient solving amplitude has been used. Prony series have been used to model the core time-dependent behavior. In conjunction with a simple indentation experiment, FEM used to formulate a novel method for finding the Prony series coefficients. By performing some low-velocity impact experiments, the impact force and displacement of the composite sandwich plates have been investigated. The results indicate that increasing the structural damping increases the contact time and missing energy and decreases the stored energy of the system. The structures with composite face sheets have a minimum ratio of upper face sheet displacement to lower face sheet displacement in comparison to those with the isotropic face sheets. Impact behavior of isotropic face sheet specimens are more flattened than that of the composite face sheets. In addition, the specific energy stored in the sandwich plates with composite face sheets, on different supports, is greater than that stored in the aluminum face sheets.

Evaluation of the feasibility for detecting hidden corrosion damage in multi-layer gusset plates using multiple inspection techniques

International Nuclear Information System (INIS)

Cobb, Adam C.; Duffer, Charles E.; Light, Glenn M.

2014-01-01

Gusset plates are used to connect the members in truss bridges and they are usually inspected using calipers or conventional thickness measurement ultrasonic testing (UT) devices. The damage mechanism of particular concern in gusset plates is corrosion and the regions most susceptible to corrosion damage are on the gusset interior surface where it intersects the chord, diagonal, and vertical members from water collecting at the interfaces. For heavily loaded gusset plates, one or more shingle plates are used to reinforce the gusset plate, creating a multi-layer structure. While the areas with corrosion damage remain near the members on the gusset plate, the shingle plates cover the gusset plate and greatly limit the surface access to the gusset plate, making UT thickness measurement impractical. Because of the critical nature of the gussets, a viable inspection strategy for multi-layer gusset assemblies must be developed. The premise of this research and development effort was to develop viable, field-deployable inspection approaches for this problem area. This paper presents three separate inspection approaches: two ultrasonic-based techniques and one radiographic approach. Each of these techniques was evaluated on a mock-up specimen provided by the Federal Highway Administration (FHWA) that is representative of gusseted connection from a truss bridge

Evaluation of the feasibility for detecting hidden corrosion damage in multi-layer gusset plates using multiple inspection techniques

Energy Technology Data Exchange (ETDEWEB)

Cobb, Adam C.; Duffer, Charles E.; Light, Glenn M. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166 (United States)

2014-02-18

Gusset plates are used to connect the members in truss bridges and they are usually inspected using calipers or conventional thickness measurement ultrasonic testing (UT) devices. The damage mechanism of particular concern in gusset plates is corrosion and the regions most susceptible to corrosion damage are on the gusset interior surface where it intersects the chord, diagonal, and vertical members from water collecting at the interfaces. For heavily loaded gusset plates, one or more shingle plates are used to reinforce the gusset plate, creating a multi-layer structure. While the areas with corrosion damage remain near the members on the gusset plate, the shingle plates cover the gusset plate and greatly limit the surface access to the gusset plate, making UT thickness measurement impractical. Because of the critical nature of the gussets, a viable inspection strategy for multi-layer gusset assemblies must be developed. The premise of this research and development effort was to develop viable, field-deployable inspection approaches for this problem area. This paper presents three separate inspection approaches: two ultrasonic-based techniques and one radiographic approach. Each of these techniques was evaluated on a mock-up specimen provided by the Federal Highway Administration (FHWA) that is representative of gusseted connection from a truss bridge.

Simplified description of out-of-plane waves in thin annular elastic plates

DEFF Research Database (Denmark)

Zadeh, Maziyar Nesari; Sorokin, Sergey

2013-01-01

Dispersion relations are derived for the out-of-plane wave propagation in planar elastic plates with constant curvature using the classical Kirchhoff thin plate theory. The dispersion diagrams and the mode shapes are compared with their counterparts for a straight plate strip and the role...... of curvature is assessed for plates with unconstrained edges. Elementary Bernoulli–Euler theory for a beam of rectangular cross-section with the circular shape of its axis is also employed to analyze the wave guide properties of this structure in its out-of-plane deformation. The applicability range...... of the elementary beam theory is validated. The wave finite element method in the formulation of the three-dimensional elasticity theory is used to ensure that the comparison of dispersion diagrams is performed in the frequency range, where the classical thin plate theory is valid. Thus, the paper summarizes...

Corrosion resistance of a magnetic stainless steel ion-plated with titanium nitride.

Science.gov (United States)

Hai, K; Sawase, T; Matsumura, H; Atsuta, M; Baba, K; Hatada, R

2000-04-01

This in vitro study evaluated the corrosion resistance of a titanium nitride (TiN) ion-plated magnetic stainless steel (447J1) for the purpose of applying a magnetic attachment system to implant-supported prostheses made of titanium. The surface hardness of the TiN ion-plated 447J1 alloy with varying TiN thickness was determined prior to the corrosion testing, and 2 micrometers thickness was confirmed to be appropriate. Ions released from the 447J1 alloy, TiN ion-plated 447J1 alloy, and titanium into a 2% lactic acid aqueous solution and 0.1 mol/L phosphate buffered saline (PBS) were determined by means of an inductively coupled plasma atomic emission spectroscopy (ICP-AES). Long-term corrosion behaviour was evaluated using a multisweep cyclic voltammetry. The ICP-AES results revealed that the 447J1 alloy released ferric ions into both media, and that the amount of released ions increased when the alloy was coupled with titanium. Although both titanium and the TiN-plated 447J1 alloy released titanium ions into lactic acid solution, ferric and chromium ions were not released from the alloy specimen for all conditions. Cyclic voltamograms indicated that the long-term corrosion resistance of the 447J1 alloy was considerably improved by ion-plating with TiN.

Corrosion fatigue crack growth in clad low-alloy steels. Part 2: Water flow rate effects in high-sulfur plate steel

International Nuclear Information System (INIS)

James, L.A.; Lee, H.B.; Wire, G.L.; Novak, S.R.; Cullen, W.H.

1997-01-01

Corrosion fatigue crack propagation tests were conducted on a high-sulfur ASTM A302-B plate steel overlaid with weld-deposited Alloy EN82H cladding. The specimens featured semi-elliptical surface cracks penetrating approximately 6.3 mm of cladding into the underlying steel. The initial crack sizes were relatively large with surface lengths of 22.8--27.3 mm, and depths of 10.5--14.1 mm. The experiments were initiated in a quasi-stagnant low-oxygen (O 2 < 10 ppb) aqueous environment at 243 C, under loading conditions (ΔK, R, cyclic frequency) conducive to environmentally assisted cracking (EAC) under quasi-stagnant conditions. Following fatigue testing under quasi-stagnant conditions where EAC was observed, the specimens were then fatigue tested under conditions where active water flow of either 1.7 m/s or 4.7 m/s was applied parallel to the crack. Earlier experiments on unclad surface-cracked specimens of the same steel exhibited EAC under quasi-stagnant conditions, but water flow rates at 1.7 m/s and 5.0 m/s parallel to the crack mitigated EAC. In the present experiments on clad specimens, water flow at approximately the same as the lower of these velocities did not mitigate EAC, and a free stream velocity approximately the same as the higher of these velocities resulted in sluggish mitigation of EAC. The lack of robust EAC mitigation was attributed to the greater crack surface roughness in the cladding interfering with flow induced within the crack cavity. An analysis employing the computational fluid dynamics code, FIDAP, confirmed that frictional forces associated with the cladding crack surface roughness reduced the interaction between the free stream and the crack cavity

A study and development of a system for the determination of porus plates permeability

International Nuclear Information System (INIS)

Leitao Junior, C.B.; Zorzetto, L.F.

1989-07-01

A device employed for the study of flux in porous media and another one employed for the determination of permeability of porous plate are presented in this work. Experimental data and calculation obtained from the above cited systems are also presented. (author) [pt

Effect of a shear modified Gurson model on damage development in a FSW tensile specimen

DEFF Research Database (Denmark)

Nielsen, Kim Lau; Tvergaard, Viggo

2009-01-01

For a friction stir welded aluminum plate the resistance to ductile failure is studied by analyzing tensile test specimens cut out across the weldline. As the stress triaxiality is rather low in these tests, the Gurson material model is not expected to give a very accurate description of the void......, such that the damage parameter does not really represent the void volume fraction. Various amounts of the additional damage evolution are compared with predictions of the original Gurson model. The analyses are carried out for different yield stress profiles transverse to the weld and for different specimen widths....... It is found that the modification does provide additional damage development in the friction stir weld, which may help to fit experimental data. But the suggested modification depends strongly on the overall stress state, and may have a too strong effect in some cases where the stress triaxiality is rather...

Development of a strain measurement method for non-plane specimens by means of computer picture processing

International Nuclear Information System (INIS)

Yoshioka, Akira; Soneda, Naoki; Yagawa, Genki; Miyoshi, Akio.

1988-01-01

Integrity Tests of the Fast Breeder Reactor components are often conducted at an elevated temperature, say 550deg C. Since high-temperature strain measurement using special strain gauges is costly and unappropriate for large and repeated strains, the authors have developed an optical strain measurement method and system based on computer picture processing and the triangulation principle. The present method enables us to measure the strain in specimen with curved surfaces. Its operation is also easy, because of the automatic distinction of marks from noises. The verification tests with a plate specimen and a cylindrical one are performed under elevated temperatures. The results show that the present method is very suitable to the tests under elevated temperatures and that the measurement error of strain is within 0.2 % (2000μ), which is reasonable considering the limitation of hardware. (author)

Philosophy, design and testing of a uniform applied load flat plate testing machine

International Nuclear Information System (INIS)

Quirk, A.; Crook, C.

1976-08-01

The presence of a central crack, and its associated plastic zones may significantly affect distribution of the stress applied by a loading machine, to a test plate. As a result the fracture stress may be affected, usually optimistically. Examples of these effects are discussed. The design of a machine in which the load is uniformly applied to the test specimen is described and preliminary test data presented. (author)

Evaluation method for ductile crack propagation in pre-strained plates; Yohizumizai no ensei kiretsu denpa hyokaho

Energy Technology Data Exchange (ETDEWEB)

Ueda, Y.; Murakawa, H. [Osaka Univ., Osaka (Japan). Welding Research Inst.; Tanigawa, M. [Hitachi Zosen Corp., Osaka (Japan)

1996-12-31

In order to investigate an effect of the plastic deformation, which was generated on ship side outer platings subjected to collision load before crack initiation, on the crack propagation behavior, crack propagation experiments using pre-strained specimens and simulation analysis by means of FEM method were carried out, to discuss about the practical simulation analysis method. As a result of the crack propagation experiments using pre-strained center notched plate specimens, a phenomenon where the crack is apt to propagate due to the pre-strains was confirmed, and measured data of crack tip opening angles were obtained. A method was proposed, in which the critical crack tip opening angle values are corrected by considering the difference between the crack shapes obtained from the FEM analysis model and actually measured, and its effectiveness was confirmed. The finite element size effect was also examined. A method using an equivalent plastic strain as the crack propagation condition was shown to determine the relationship between the element size and the critical value of equivalent plastic strain. 5 refs., 21 figs., 4 tabs.

Evaluation method for ductile crack propagation in pre-strained plates; Yohizumizai no ensei kiretsu denpa hyokaho

Energy Technology Data Exchange (ETDEWEB)

Ueda, Y; Murakawa, H [Osaka Univ., Osaka (Japan). Welding Research Inst.; Tanigawa, M [Hitachi Zosen Corp., Osaka (Japan)

1997-12-31

In order to investigate an effect of the plastic deformation, which was generated on ship side outer platings subjected to collision load before crack initiation, on the crack propagation behavior, crack propagation experiments using pre-strained specimens and simulation analysis by means of FEM method were carried out, to discuss about the practical simulation analysis method. As a result of the crack propagation experiments using pre-strained center notched plate specimens, a phenomenon where the crack is apt to propagate due to the pre-strains was confirmed, and measured data of crack tip opening angles were obtained. A method was proposed, in which the critical crack tip opening angle values are corrected by considering the difference between the crack shapes obtained from the FEM analysis model and actually measured, and its effectiveness was confirmed. The finite element size effect was also examined. A method using an equivalent plastic strain as the crack propagation condition was shown to determine the relationship between the element size and the critical value of equivalent plastic strain. 5 refs., 21 figs., 4 tabs.

Electroless Plating on Plastic Induced by Selective Laser Activation

DEFF Research Database (Denmark)

Zhang, Yang; Tang, Peter Torben; Hansen, Hans Nørgaard

2009-01-01

This paper presents a new method for selective micro metallization of polymers. A Nd:YAG laser is employed to draw patterns on polymer surfaces that are submerged in a liquid (usually water). After subsequent activation with palladium chloride and followed by auto-catalytic electroless plating, c...

Inspection of welded zone and flat plate using flexible ECA probe

Energy Technology Data Exchange (ETDEWEB)

Lee, Chang Jun; Lee, Kyu Sung; Shin, Chung Ho; Lee, Kyoung Jun; Jang, Yoon Young [ANSCO Inc., Daejeon (Korea, Republic of)

2016-08-15

This paper aims to compare the ability to detect notch defects existing in the plate and welded area using a flexible ECA (eddy current array) probe with OmniScan MX and MS-5800E. The characteristics of signals with various frequencies and lift-offs were also compared. As a result, when signals of frequencies 500, 1000, and 1500 kHz were used, the amplitude of the signal increased, as the depth of the notch increased, but reduced linearly in accordance with the lift-off variation. In addition, the detection sensitivity of the weld defect was found to be closely related to the contact surface of the probe and specimen. In this paper, it was demonstrated that the detection sensitivity was excellent when the contact surface of the probe and the specimen was sufficient, but it was poor when the contact surface was insufficient.

A simple cryo-holder facilitates specimen observation under a conventional scanning electron microscope.

Science.gov (United States)

Tang, Chih-Yuan; Huang, Rong-Nan; Kuo-Huang, Ling-Long; Kuo, Tai-Chih; Yang, Ya-Yun; Lin, Ching-Yeh; Jane, Wann-Neng; Chen, Shiang-Jiuun

2012-02-01

A pre-cryogenic holder (cryo-holder) facilitating cryo-specimen observation under a conventional scanning electron microscope (SEM) is described. This cryo-holder includes a specimen-holding unit (the stub) and a cryogenic energy-storing unit (a composite of three cylinders assembled with a screw). After cooling, the cryo-holder can continue supplying cryogenic energy to extend the observation time for the specimen in a conventional SEM. Moreover, the cryogenic energy-storing unit could retain appropriate liquid nitrogen that can evaporate to prevent frost deposition on the surface of the specimen. This device is proved feasible for various tissues and cells, and can be applied to the fields of both biology and material science. We have employed this novel cryo-holder for observation of yeast cells, trichome, and epidermal cells in the leaf of Arabidopsis thaliana, compound eyes of insects, red blood cells, filiform papillae on the surface of rat tongue, agar medium, water molecules, penicillium, etc. All results suggested that the newly designed cryo-holder is applicable for cryo-specimen observation under a conventional SEM without cooling system. Most importantly, the design of this cryo-holder is simple and easy to operate and could adapt a conventional SEM to a plain type cryo-SEM affordable for most laboratories. Copyright © 2011 Wiley Periodicals, Inc.

Miniature specimen technology for postirradiation fatigue crack growth testing

International Nuclear Information System (INIS)

Mervyn, D.A.; Ermi, A.M.

1979-01-01

Current magnetic fusion reactor design concepts require that the fatigue behavior of candidate first wall materials be characterized. Fatigue crack growth may, in fact, be the design limiting factor in these cyclic reactor concepts given the inevitable presence of crack-like flaws in fabricated sheet structures. Miniature specimen technology has been developed to provide the large data base necessary to characterize irradiation effects on the fatigue crack growth behavior. An electrical potential method of measuring crack growth rates is employed on miniature center-cracked-tension specimens (1.27 cm x 2.54 cm x 0.061 cm). Results of a baseline study on 20% cold-worked 316 stainless steel, which was tested in an in-cell prototypic fatigue machine, are presented. The miniature fatigue machine is designed for low cost, on-line, real time testing of irradiated fusion candidate alloys. It will enable large scale characterization and development of candidate first wall alloys

Morphologic and radiologic data of isolated vertebral end-plates under particular consideration of radiodensitometry

International Nuclear Information System (INIS)

Unflath, U.

1979-01-01

The intention was to find examination techniques for macroscopico-morphological diagnosis, for quantification of the concavity and methods for roentgenologico-densitometric analysis of vertebral end-plates. The following factors were used for macromorphologic diagnosis: osteophytes, ridge constitution, ridge transition, cribriform plate and concavity. The radiodensitometric analysis comprised investigation of bone density, anisotropy and ridge mineralisation. The specimen were radiographed on a mammograph together with calcium chloride solutions of increasing concentration. Statistically significant differences in the behaviour of basal and upper plates were not observed. With reference to the factors osteophytes and ridge constitution the basal plates seem to be morphologically more variable than the upper plates. It resulted that the features absolute concavity and concavity quotient are highly appropriate factors to document the constitution of the isolated vertebral end-plates. Also the features density, anisotropy and ridge mineralisation were found to be useful for documentation. The result of data correlation was that high concavity quotients are accompanied by macroscopically medium- to small-sized pores. Density and anisotropy of the overall profiles do not show correlation, but voluminous cribriform laminae tend to develop more inhomogenic structures. As to be expected, bone density increases with macroscopic fine porosity. The higher the concavity quotient is, the smaller are the values for density, ridge mineralisation and anisotropy. Thus a high degree of vertebral end-plate concavity indicates reduced bone density and lower mineral content. (orig./MG) [de

Laparoscopic specimen retrieval bags.

Science.gov (United States)

Smorgick, Noam

2014-10-01

Specimen retrieval bags have long been used in laparoscopic gynecologic surgery for contained removal of adnexal cysts and masses. More recently, the concerns regarding spread of malignant cells during mechanical morcellation of myoma have led to an additional use of specimen retrieval bags for contained "in-bag" morcellation. This review will discuss the indications for use retrieval bags in gynecologic endoscopy, and describe the different specimen bags available to date.

Numerical Study on the Effect of Distribution Plates in the Manifolds on the Flow Distribution and Thermal Performance of a Flat Plate Solar Collector

Directory of Open Access Journals (Sweden)

Juan Manuel García-Guendulain

2018-04-01

Full Text Available Flow maldistribution represents a problem of particular interest in the engineering field for several thermal systems. In flat plate solar collectors, the thermal efficiency strongly depends on the flow distribution through the riser tubes, where a uniform distribution causes a uniform temperature distribution and therefore a higher efficiency. In this work, a Computational Fluid Dynamics (CFD numerical analysis has been carried out using the commercial software FLUENT®, in order to determine the flow distribution, pressure drop and hence the thermal efficiency of a solar collector with distribution flow plates inside the manifolds. The obtained numerical solution for this type of thermal systems has been validated with experimental results available in literature for laminar and turbulent flow. Four distribution plate configurations were analyzed. Results show that using two distribution plates in each of both manifolds improves the flow uniformity up to 40% under the same operating conditions when distribution plates are not used. Besides, it is shown that there exists an increase in the overall pressure drop which is practically negligible for the tilt angles commonly employed in the installation of flat plate solar collectors in Mexico. The use of closed end distribution plates on the dividing and combining manifolds allows the thermal efficiency to become close to the ideal thermal efficiency which is obtained with a uniform flow distribution.

Use of globally unique identifiers (GUIDs) to link herbarium specimen records to physical specimens.

Science.gov (United States)

Nelson, Gil; Sweeney, Patrick; Gilbert, Edward

2018-02-01

With the advent of the U.S. National Science Foundation's Advancing Digitization of Biodiversity Collections program and related worldwide digitization initiatives, the rate of herbarium specimen digitization in the United States has expanded exponentially. As the number of electronic herbarium records proliferates, the importance of linking these records to the physical specimens they represent as well as to related records from other sources will intensify. Although a rich and diverse literature has developed over the past decade that addresses the use of specimen identifiers for facilitating linking across the internet, few implementable guidelines or recommended practices for herbaria have been advanced. Here we review this literature with the express purpose of distilling a specific set of recommendations especially tailored to herbarium specimen digitization, curation, and management. We argue that associating globally unique identifiers (GUIDs) with physical herbarium specimens and including these identifiers in all electronic records about those specimens is essential to effective digital data curation. We also address practical applications for ensuring these associations.

Fracture assessment of HSST Plate 14 shallow-flaw cruciform bend specimens tested under biaxial loading conditions

Energy Technology Data Exchange (ETDEWEB)

Bass, B.R.; McAfee, W.J.; Williams, P.T.; Pennell, W.E.

1998-06-01

A technology to determine shallow-flaw fracture toughness of reactor pressure vessel (RPV) steels is being developed for application to the safety assessment of RPVs containing postulated shallow surface flaws. Matrices of cruciform beam tests were developed to investigate and quantify the effects of temperature, biaxial loading, and specimen size on fracture initiation toughness of two-dimensional (constant depth), shallow, surface flaws. The cruciform beam specimens were developed at Oak Ridge National Laboratory (ORNL) to introduce a far-field, out-of-plane biaxial stress component in the test section that approximates the nonlinear stresses resulting from pressurized-thermal-shock or pressure-temperature loading of an RPV. Tests were conducted under biaxial load ratios ranging from uniaxial to equibiaxial. These tests demonstrated that biaxial loading can have a pronounced effect on shallow-flaw fracture toughness in the lower transition temperature region for an RPV material. The cruciform fracture toughness data were used to evaluate fracture methodologies for predicting the observed effects of biaxial loading on shallow-flaw fracture toughness. Initial emphasis was placed on assessment of stress-based methodologies, namely, the J-Q formulation, the Dodds-Anderson toughness scaling model, and the Weibull approach. Applications of these methodologies based on the hydrostatic stress fracture criterion indicated an effect of loading-biaxiality on fracture toughness; the conventional maximum principal stress criterion indicated no effect. A three-parameter Weibull model based on the hydrostatic stress criterion is shown to correlate the experimentally observed biaxial effect on cleavage fracture toughness by providing a scaling mechanism between uniaxial and biaxial loading states.

Magnetoelastic bending and snapping of ferromagnetic plates in oblique magnetic fields

International Nuclear Information System (INIS)

Zhou Youhe

1995-01-01

Ferritic stainless steel has been considered for structural components such as first walls and blankets of fusion power reactors because the material shows low rates of irradiation swelling. Since it is magnetizable, the magnetoelastic interaction between magnetic field and deformation of the structures in a fusion reactor is so strong that their safety is of concern due to the magnetoelastic bending, buckling and magnetic damping, etc. Basic research of the magnetoelastic characteristics of ferromagnetic plate has been paid special attention by researchers. In this paper, the magnetoelastic bending and snapping are studied for a ferromagnetic plate in an oblique magnetic field. The theoretical model is based on the variational principle where the functional is employed as real total energy in the system including external work. The obtained expression of magnetic force on the plate is the same as that derived from the dipole model when the total magnetic field in the ferromagnetic medium is considered. In order to effectively solve the nonlinearly coupled interaction problem between magnetic field and mechanical deformation, a numerical program combining the finite element method for analyzing the magnetic field with the finite difference technique for finding out the bending deformation of the plate is employed to obtain the solution of magnetoelastic bending of a soft ferromagnetic plate. The numerical calculations are carried out for the typical example of a ferromagnetic cantilevered beam-plate in an oblique magnetic field. From the bending curves, that is the tip deflection versus applied magnetic fields, the critical magnetic field for the magnetoelastic snapping is predicted by the Southwell plot. The theoretical predictions show that the critical magnetic field decreases with the increase in incident angle of the oblique magnetic field. By the effect of incident angle on the magnetic buckling, the discrepancy between theoretical and experimental data can

Performance of a thermal neutron radiographic system using imaging plates

International Nuclear Information System (INIS)

Silvani, Maria Ines; Almeida, Gevaldo L. de; Furieri, Rosanne; Lopes, Ricardo T.

2009-01-01

A performance evaluation of a neutron radiographic system equipped with a thermal neutron sensitive imaging plate has been undertaken. It includes the assessment of spatial resolution, linearity, dynamic range and the response to exposure time, as well as a comparison of these parameters with the equivalent ones for neutron radiography employing conventional films and a gadolinium foil as converter. The evaluation and comparison between the radiographic systems have been performed at the Instituto de Engenharia Nuclear - CNEN, using the Argonauta Reactor as source of thermal neutrons and a commercially available imaging plate reader. (author)

Mathematical methods for elastic plates

CERN Document Server

Constanda, Christian

2014-01-01

Mathematical models of deformation of elastic plates are used by applied mathematicians and engineers in connection with a wide range of practical applications, from microchip production to the construction of skyscrapers and aircraft. This book employs two important analytic techniques to solve the fundamental boundary value problems for the theory of plates with transverse shear deformation, which offers a more complete picture of the physical process of bending than Kirchhoff’s classical one.   The first method transfers the ellipticity of the governing system to the boundary, leading to singular integral equations on the contour of the domain. These equations, established on the basis of the properties of suitable layer potentials, are then solved in spaces of smooth (Hölder continuous and Hölder continuously differentiable) functions.   The second technique rewrites the differential system in terms of complex variables and fully integrates it, expressing the solution as a combination of complex ana...

Steady-state, elastic-plastic growth of slanted cracks in symmetrically loaded plates

DEFF Research Database (Denmark)

Nielsen, Kim Lau; Hutchinson, J. W.

2017-01-01

parameter through the plate in the plastic zone at the crack tip. The distribution of the mode I and mode III stress intensity factors along the crack front are obtained for the elastic problem. The out-of-plane bending constraint imposed on the plate significantly influences the mixed mode behavior along......Elastic and elastic-plastic results are obtained for a semi-infinite slanted through-crack propagating in a symmetrically loaded plate strip with the aim of providing theoretical background to commonly observed plate tearing behavior. Were it is not for the slant of the crack through the thickness...... of the plate, the problem would be mode I, but due to the slant the local conditions along the crack front are a combination of mode I and mode III. A three-dimensional formulation for steady-state crack propagation is employed to generate distributions of effective stress, stress triaxiality and Lode...

Cold plate

Energy Technology Data Exchange (ETDEWEB)

Marroquin, Christopher M.; O' Connell, Kevin M.; Schultz, Mark D.; Tian, Shurong

2018-02-13

A cold plate, an electronic assembly including a cold plate, and a method for forming a cold plate are provided. The cold plate includes an interface plate and an opposing plate that form a plenum. The cold plate includes a plurality of active areas arranged for alignment over respective heat generating portions of an electronic assembly, and non-active areas between the active areas. A cooling fluid flows through the plenum. The plenum, at the non-active areas, has a reduced width and/or reduced height relative to the plenum at the active areas. The reduced width and/or height of the plenum, and exterior dimensions of cold plate, at the non-active areas allow the non-active areas to flex to accommodate surface variations of the electronics assembly. The reduced width and/or height non-active areas can be specifically shaped to fit between physical features of the electronics assembly.

Urine culture - catheterized specimen

Science.gov (United States)

Culture - urine - catheterized specimen; Urine culture - catheterization; Catheterized urine specimen culture ... urinary tract infections may be found in the culture. This is called a contaminant. You may not ...

Investigation of heave response of the deepwater octagonal FDPSO using various heave plate configurations

Science.gov (United States)

Yu, Chenfang; Hu, Zhiqiang; Wang, Shisheng

2017-12-01

Heave plates can be employed to control undesirable heave motion amplitudes of the deepwater octagonal Floating, Drilling, Production, Storage, and Offloading (FDPSO) platform. Numerical simulations and model tests were applied to analyze and investigate the hydrodynamic response and the feasibility of the heave plate configurations. The diameter and the depth below the free surface of a single-layer heave plate, as well as the spacing of two-layer heave plates, were considered as the primary variables when studying the effect of heave plates on FDPSO hydrodynamics. The analysis results indicate that the heave plate diameter significantly affects the heave hydrodynamics, and heave performance could be improved with an increased diameter. In addition, increasing the depth below the free surface of a single-layer heave plate does not effectively suppress the heave motion within the range of draft depths tested. The target FDPSO obtained better heave characteristics with increased spacing between the two-layer heave plates. Furthermore, the global performances of the octagonal FDPSO with these typical heave plate configurations were comparatively analyzed. The results indicate that from a hydrodynamic point of view, the single-layer heave plate configuration has an advantage over the two-layer heave plate configuration.

HMSRP Hawaiian Monk Seal Specimen Data (includes physical specimens, collection information, status, storage locations, and laboratory results associated with individual specimens)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set includes physical specimens, paper logs and Freezerworks database of all logged information on specimens collected from Hawaiian monk seals since 1975....

Characterization and testing of monolithic RERTR fuel plates

Energy Technology Data Exchange (ETDEWEB)

Keiser, D.D.; Jue, J.F.; Burkes, D.E. [Idaho National Lab., Idaho Falls, ID (United States)

2007-07-01

Monolithic fuel plates are being developed as a LEU (low enrichment uranium) fuel for application in research reactors throughout the world. These fuel plates are comprised of a U-Mo alloy foil encased in aluminum alloy cladding. Three different fabrication techniques have been looked at for producing monolithic fuel plates: hot isostatic pressing (HIP), transient liquid phase bonding (TLPB), and friction stir welding (FSW). Of these three techniques, HIP and FSW are currently being emphasized. As part of the development of these fabrication techniques, fuel plates are characterized and tested to determine properties like hardness and the bond strength at the interface between the fuel and cladding. Testing of HIP-made samples indicates that the foil/cladding interaction behavior depends on the Mo content in the UMo foil, the measured hardness values are quite different for the fuel, cladding, and interaction zone phase and Ti, Zr and Nb are the most effective diffusion barriers. For FSW samples, there is a dependence of the bond strength at the foil/cladding interface on the type of tool that is employed for performing the actual FSW process. (authors)

Identification of Mycobacterium tuberculosis in Clinical Specimens of Patients Suspected of Having Extrapulmonary Tuberculosis by Application of Nested PCR on Five Different Genes.

Science.gov (United States)

Khosravi, Azar D; Alami, Ameneh; Meghdadi, Hossein; Hosseini, Atta A

2017-01-01

Definitive and rapid diagnosis of extrapulmonary tuberculosis (EPTB) is challenging since conventional techniques have limitations due to the paucibacillary nature of the disease. To increase the sensitivity of detection of Mycobacterium tuberculosis (MTB) in EPTB specimens, we performed a nested PCR assay targeting several genes of MTB on EPTB specimens. A total of 100 clinical specimens from suspected cases of EPTB were processed. Standard staining for acid fast bacilli (AFB) was performed as the preliminary screening test. Extracted DNAs from specimens were subjected to Nested PCR technique for the detection of five different MTB target genes of IS6110, IS1081, hsp65kd, mbp64 , and mtp40 . On performing AFB staining, only 13% of specimens were positive, of which ascites fluid (33.3%), followed by pleural effusion (30.8%) showed the greatest AFB positivity rate. We demonstrated slight improvement in yields in lymph node which comprised the majority of specimens in this study, by employing PCR targeted to IS6110 - and hsp65-genes in comparison to AFB staining. However, the yields in ascites fluid and pleural effusion were not substantially improved by PCR, but those from bone and wound were, as in nested PCR employing either gene, the same positivity rate were obtained for ascites fluid (33.3%), while for pleural effusion specimens only IS1081 based PCR showed identical positivity rate with AFB stain (30.8%). The results for bone and wound specimens, however, demonstrated an improved yield mainly by employing IS1081 gene. Here, we report higher detection rate of EPTB in clinical specimens using five different targeted MTB genes. This nested PCR approach facilitates the comparison and the selection of the most frequently detected genes. Of course this study demonstrated the priority of IS1081 followed by mtp40 and IS6110 , among the five tested genes and indicates the effectiveness of any of the three genes in the design of an efficient nested-PCR test that

Assessment of the stability of DNA in specimens collected under conditions for drug testing-A pilot study.

Science.gov (United States)

White, Robert M; Mitchell, John M; Hart, E Dale; Evans, Amy; Meaders, Meredith; Norsworthy, Sarah E; Hayes, Eugene D; Flegel, Ron; Maha, George C; Shaffer, Megan D; Hall, Erin M; Rogers, Kelley

2018-02-01

For forensic biological sample collections, the specimen donor is linked solidly to his or her specimen through a chain of custody (CoC) sometimes referenced as a chain of evidence. Rarely, a donor may deny that a urine or oral fluid (OF) specimen is his or her specimen even with a patent CoC. The goal of this pilot study was to determine the potential effects of short-term storage on the quality and quantity of DNA in both types of specimen under conditions that may be encountered with employment-related drug testing specimens. Fresh urine and freshly collected oral fluid all produced complete STR profiles. For the "pad" type OF collectors, acceptable DNA was extractable both from the buffer/preservative and the pad. Although fresh urine and OF produced complete STR profiles, partial profiles were obtained after storage for most samples. An exception was the DNA in the Quantisal OF collector, from which a complete profile was obtained for both freshly collected OF and stored OF. Copyright © 2017 Elsevier B.V. All rights reserved.

Measurements of Residual Stresses In Cold-Rolled 304 Stainless Steel Plates Using X-Ray Diffraction with Rietveld Refinement Method

International Nuclear Information System (INIS)

Parikin; Killen, P; Rafterry, A.

2009-01-01

The determination of the residual stresses using X-ray powder diffraction in a series of cold-rolled 304 stainless steel plates, deforming 0, 34, 84, 152, 158, 175 and 196 % reduction in thickness has been carried out. The diffraction data were analyzed using the Rietveld structure refinement method. The analysis shows that for all specimens, the martensite particles are closely in compression and the austenite matrix is in tension. Both the martensite and austenite, for a sample reducing 34% in thickness (containing of about 1% martensite phase) the average lattice strains are anisotropic and decrease approximately exponential with an increase in the corresponding percent reduction (essentially phase content). It is shown that this feature can be qualitatively understood by taking into consideration the thermal expansion mismatch between the martensite and austenite grains. Also, for all cold-rolled stainless steel specimens, the diffraction peaks are broader than the unrolled one (instrumental resolution), indicating that the strains in these specimens are inhomogeneous. From an analysis of the refined peak shape parameters, the average root-mean square strain, which describes the distribution of the inhomogeneous strain field, was predicted. The average residual stresses in cold-rolled 304 stainless steel plates showed a combination effect of hydrostatic stresses of the martensite particles and the austenite matrix. (author)

Microstructures and Mechanical Properties of Austempering SUS440 Steel Thin Plates

Directory of Open Access Journals (Sweden)

Cheng-Yi Chen

2016-02-01

Full Text Available SUS440 is a high-carbon stainless steel, and its martensite matrix has high heat resistance, high corrosion resistance, and high pressure resistance. It has been widely used in mechanical parts and critical materials. However, the SUS440 martempered matrix has reliability problems in thin plate applications and thus research uses different austempering heat treatments (tempering temperature: 200 °C–400 °C to obtain a matrix containing bainite, retained austenite, martensite, and the M7C3 phase to investigate the relationships between the resulting microstructure and tensile mechanical properties. Experimental data showed that the austempering conditions of the specimen affected the volume fraction of phases and distribution of carbides. After austenitizing heat treatment (1080 °C for 30 min, the austempering of the SUS440 thin plates was carried out at a salt-bath temperature 300 °C for 120 min and water quenching was then used to obtain the bainite matrix with fine carbides, with the resulting material having a higher tensile fracture strength and average hardness (HRA 76 makes it suitable for use as a high-strength thin plate for industrial applications.

A study on plate anchor detailing systems of shear re-bar

International Nuclear Information System (INIS)

Tsurumaki, S.; Ujiie, K.; Nishikawa, T.; Kitayama, K.

1995-01-01

For shell walls and base slabs in reactor buildings, besides a large amount of main bars, numerous shear re-bars have been employed to resist to out-of-plane force. As a result , detailing work involving shear re-bar is extremely involved. For example, the employed re-bar anchor method differs from the ordinary methods in which, a end of shear re-bar with 135-degrees hook or with anchor plate type and another re-bar end with 90-degrees hook are used. However the structural characteristics in members using shear re-bar of the bolt-mounted anchor plate have not yet been examined. A test was performed to confirm the effects of anchor methods for shear re-bars on shearing behavior of members. This paper describes the test plan, method and results. (author). 12 figs., 7 tabs

Variation in Lateral Plate Quality in Threespine Stickleback from Fresh, Brackish and Marine Water: A Micro-Computed Tomography Study.

Directory of Open Access Journals (Sweden)

Elisabeth Wiig

Full Text Available It is important to understand the drivers leading to adaptive phenotypic diversity within and among species. The threespine stickleback (Gasterosteus aculeatus has become a model system for investigating the genetic and phenotypic responses during repeated colonization of fresh waters from the original marine habitat. During the freshwater colonization process there has been a recurrent and parallel reduction in the number of lateral bone plates, making it a suitable system for studying adaptability and parallel evolution.The aim of this study was to investigate an alternative evolutionary path of lateral plate reduction, where lateral plates are reduced in size rather than number.A total of 72 threespine stickleback individuals from freshwater (n = 54, brackish water (n = 27 and marine water (n = 9 were analysed using microcomputed tomography (μCT to determine variation in size, thickness and structure of the lateral plates. Furthermore, whole-body bone volume, and bone volume, bone surface and porosity of lateral plate number 4 were quantified in all specimens from each environment.The results showed a significant difference in plate size (area and volume among populations, where threespine stickleback from polymorphic freshwater and brackish water populations displayed lateral plates reduced in size (area and volume compared to marine stickleback.Reduction of lateral plates in threespine stickleback in fresh and brackish water occurs by both plate loss and reduction in plate size (area and volume.

Ductile fracture toughness of modified A 302 grade B plate materials. Volume 2

International Nuclear Information System (INIS)

McCabe, D.E.; Manneschmidt, E.T.; Swain, R.L.

1997-02-01

The objective of this work was to develop ductile fracture toughness data in the form of J-R curves for modified A 302 grade B plate materials typical of those used in fabricating reactor pressure vessels. A previous experimental study at Materials Engineering Associates (MEA) on one particular heat of A 302 grade B plate showed decreasing J-R curves with increased specimen thickness. This characteristic has not been observed in numerous tests made on the more recent production materials of A 533 grade B and A 508 class 2 pressure vessel steels. It was unknown if the departure from norm for the MEA material was a generic characteristic for all heats of A 302 grade B steels or just unique to that one particular plate. Seven heats of modified A 302 grade B steel and one heat of vintage A 533 grade B steel were provided to this project by the General Electric Company of San Jose, California. All plates were tested for chemical content, tensile properties, Charpy transition temperature curves, drop-weight nil-ductility transition (NDT) temperature, and J-R curves. Tensile tests were made in the three principal orientations and at four temperatures, ranging from room temperature to 550 degrees F (288 degrees C). Charpy V-notch transition temperature curves were obtained in longitudinal, transverse, and short transverse orientations. J-R curves were made using four specimen sizes (1/2T, IT, 2T, and 4T). None of the seven heats of modified A 302 grade showed size effects of any consequence on the J-R curve behavior. Crack orientation effects were present, but none were severe enough to be reported as atypical. A test temperature increase from 180 to 550 degrees F (82 to 288 degrees C) produced the usual loss in J-R curve fracture toughness. Generic J-R curves and mathematical curve fits to the same were generated to represent each heat of material. This volume is a compilation of all data developed

Chaos control for the plates subjected to subsonic flow

Science.gov (United States)

Norouzi, Hamed; Younesian, Davood

2016-07-01

The suppression of chaotic motion in viscoelastic plates driven by external subsonic air flow is studied. Nonlinear oscillation of the plate is modeled by the von-Kármán plate theory. The fluid-solid interaction is taken into account. Galerkin's approach is employed to transform the partial differential equations of the system into the time domain. The corresponding homoclinic orbits of the unperturbed Hamiltonian system are obtained. In order to study the chaotic behavior of the plate, Melnikov's integral is analytically applied and the threshold of the excitation amplitude and frequency for the occurrence of chaos is presented. It is found that adding a parametric perturbation to the system in terms of an excitation with the same frequency of the external force can lead to eliminate chaos. Variations of the Lyapunov exponent and bifurcation diagrams are provided to analyze the chaotic and periodic responses. Two perturbation-based control strategies are proposed. In the first scenario, the amplitude of control forces reads a constant value that should be precisely determined. In the second strategy, this amplitude can be proportional to the deflection of the plate. The performance of each controller is investigated and it is found that the second scenario would be more efficient.

FINITE ELEMENT MODELING OF THIN CIRCULAR SANDWICH PLATES DEFLECTION

Directory of Open Access Journals (Sweden)

K. S. Kurachka

2014-01-01

Full Text Available A mathematical model of a thin circular sandwich plate being under the vertical load is proposed. The model employs the finite element method and takes advantage of an axisymmetric finite element that leads to the small dimension of the resulting stiffness matrix and sufficient accuracy for practical calculations. The analytical expressions for computing local stiffness matrices are found, which can significantly speed up the process of forming the global stiffness matrix and increase the accuracy of calculations. A software is under development and verification. The discrepancy between the results of the mathematical model and those of analytical formulas for homogeneous thin circularsandwich plates does not exceed 7%.

One-way mode transmission in one-dimensional phononic crystal plates

Science.gov (United States)

Zhu, Xuefeng; Zou, Xinye; Liang, Bin; Cheng, Jianchun

2010-12-01

We investigate theoretically the band structures of one-dimensional phononic crystal (PC) plates with both antisymmetric and symmetric structures, and show how unidirectional transmission behavior can be obtained for either antisymmetric waves (A modes) or symmetric waves (S modes) by exploiting mode conversion and selection in the linear plate systems. The theoretical approach is illustrated for one PC plate example where unidirectional transmission behavior is obtained in certain frequency bands. Employing harmonic frequency analysis, we numerically demonstrate the one-way mode transmission for the PC plate with finite superlattice by calculating the steady-state displacement fields under A modes source (or S modes source) in forward and backward direction, respectively. The results show that the incident waves from A modes source (or S modes source) are transformed into S modes waves (or A modes waves) after passing through the superlattice in the forward direction and the Lamb wave rejections in the backward direction are striking with a power extinction ratio of more than 1000. The present structure can be easily extended to two-dimensional PC plate and efficiently encourage practical studies of experimental realization which is believed to have much significance for one-way Lamb wave mode transmission.

Non-linear analysis of skew thin plate by finite difference method

International Nuclear Information System (INIS)

Kim, Chi Kyung; Hwang, Myung Hwan

2012-01-01

This paper deals with a discrete analysis capability for predicting the geometrically nonlinear behavior of skew thin plate subjected to uniform pressure. The differential equations are discretized by means of the finite difference method which are used to determine the deflections and the in-plane stress functions of plates and reduced to several sets of linear algebraic simultaneous equations. For the geometrically non-linear, large deflection behavior of the plate, the non-linear plate theory is used for the analysis. An iterative scheme is employed to solve these quasi-linear algebraic equations. Several problems are solved which illustrate the potential of the method for predicting the finite deflection and stress. For increasing lateral pressures, the maximum principal tensile stress occurs at the center of the plate and migrates toward the corners as the load increases. It was deemed important to describe the locations of the maximum principal tensile stress as it occurs. The load-deflection relations and the maximum bending and membrane stresses for each case are presented and discussed

Electroless nickel plating on abs plastics from nickel chloride and nickel sulfate baths

International Nuclear Information System (INIS)

Inam-ul-haque; Ahmad, S.; Khan, A.

2005-01-01

Aqueous acid nickel chloride and alkaline nickel sulphate bath were studied for electroless nickel planting on acrylonitrile-butadiene-styrene (ABS) plastic. Before electroless nickel plating, specimens were etched, sensitized and activated. Effects of sodium hypophosphite and sodium citrate concentration on the electroless nickel plating thickness were discussed. Aqueous acid nickel chloride bath comprising, nickel chloride 10 g/L, sodium hypophosphite 40 g/L, sodium citrate 40g/L at pH 5.5, temperature 85 deg. C and density of 1 Be/ for thirty minutes gave best coating thickness in micrometer. It was found that acid nickel chloride bath had a greater stability, wide operating range and better coating thickness results than alkaline nickel sulphate bath. Acid nickel chloride bath gave better coating thickness than alkaline nickel sulfate bath

Screen-film specimen radiography

International Nuclear Information System (INIS)

Shepard, S.J.; Hogan, J.; Schreck, B.

1990-01-01

This paper reports on the reproducibility and quality of biopsy specimen radiographs, a unique phototimed cabinet x-ray system is being developed. The system utilizes specially modified Kodal Min-R cassettes and will be compatible with current mammographic films. Tube voltages are in the 14-20-kVp range with 0.1-1.0-second exposure times. A top-hat type compression device is used (1) to compress the specimen to uniform thickness, (2) to measure the specimen thickness and determine optimum kVp, and (3) to superimpose a grid over the specimen for identification of objects of radiographic interest. The phototiming circuit developed specifically for this purpose will be described along with the modified Min-R cassette. Characteristics of the generator and cabinet will also be described. Tests will be performed on phantoms to evaluate the system limitations

Design of creep machine and creep specimen chamber for carrying out creep tests in flowing liquid sodium

Energy Technology Data Exchange (ETDEWEB)

Ravi, S., E-mail: sravi@igcar.gov.in; Laha, K.; Sakthy, S.; Mathew, M.D.; Jayakumar, T.

2014-02-15

Highlights: • Design of a lever type creep machine for carrying out creep test in flowing sodium. • Leveling of lever during creep was achieved by automated movement of fulcrum. • Design of creep chamber for providing constant sodium flow rate across creep specimen. • Minimum use of bellow in chamber for sodium containment and mechanical isolation. • Mini-lever mechanism to counter balance load reduction on specimen due to bellow stiffness. - Abstract: A creep testing system has been designed, fabricated, installed and validated for carrying out creep tests in flowing liquid sodium. The testing system consists of two sections namely creep testing machine and an environmental chamber. The testing system has the ability of (i) applying tensile load to the test specimen through a lever, (ii) monitoring continuously the creep elongation and (iii) allowing sodium to flow around the creep specimen at constant velocity. The annular space between the creep specimen and the environmental chamber has been suitably designed to maintain constant sodium flow velocity. Primary and secondary bellows are employed in the environmental chamber to (i) mechanically isolate the creep specimen, (ii) prevent the flowing sodium in contact with air and (iii) maintain an argon gas cover to the leaking sodium if any from primary bellow, with a provision to an alarm get activated by a spark plug. The lever-horizontality during creep test has been maintained by automatically lifting up the fulcrum instead of lowering down the pull rod as conventionally used. A mini lever mechanism has been incorporated in the load train to counter balance the load reduction on specimen from the changing stiffness of the bellows. The validation of the testing system has been established by carrying out creep tests on 316L(N) stainless steel at 873 K over a wide stress range and comparing the results with those obtained in air by employing the developed and conventional creep testing machines.

Tunable Ampere phase plate for low dose imaging of biomolecular complexes

DEFF Research Database (Denmark)

Tavabi, Amir H.; Beleggia, Marco; Migunov, Vadim

2018-01-01

A novel device that can be used as a tunable support-free phase plate for transmission electron microscopy of weakly scattering specimens is described. The device relies on the generation of a controlled phase shift by the magnetic field of a segment of current-carrying wire that is oriented...... parallel or antiparallel to the electron beam. The validity of the concept is established using both experimental electron holographic measurements and a theoretical model based on Ampere's law. Computer simulations are used to illustrate the resulting contrast enhancement for studies of biological cells...

Stable and unstable crack growth in Type 304 stainless steel plate

International Nuclear Information System (INIS)

Yagawa, G.

1984-01-01

Experimental and theoretical results on stable as well as unstable fractures for Type 304 stainless steel plates with a central crack subjected to tension force are given. In the experiment using a testing machine with a special spring for high compliance, the transition points from the stable to the unstable crack growth are observed and comparisons are made between the test results and the finite element solutions. A round robin calculation for the elastic-plastic stable crack growth using one of the specimens mentioned above is also given. (orig.)

Investigation of the ductile fracture properties of Type 304 stainless steel plate, welds, and 4-inch pipe

International Nuclear Information System (INIS)

Vassilaros, M.G.; Hays, R.A.; Gudas, J.P.

1985-01-01

J-integral fracture toughness tests were performed on welded 304 stainless steel 2-inch plate and 4-inch diameter pipe. The 2-inch plate was welded using a hot-wire automatic gas tungsten arc process. The tests were performed at 550 0 F, 300 0 F and room temperature. The results of the J-integral tests indicate that the Jsub(Ic) of the base plate ranged from 4400 to 6100 in lbs/in 2 at 550 0 F. The Jsub(Ic) values for the tests performed at 300 0 F and room temperature were beyond the measurement capacity of the specimens and appear to indicate that Jsub(Ic) was greater than 8000 in lb/in 2 . The J-integral tests performed on the weld metal specimens indicate that the Jsub(Ic) values ranged from 930 to 2150 in lbs/in 2 at 550 0 F. The Jsub(Ic) values of the weld metal specimens tested at 300 0 F and room temperature were 2300 and 3000 in lbs/in 2 respectively. One HAZ specimen was tested at 550 0 F and found to have a Jsub(Ic) value of 2980 in lbs/in 2 which indicates that the HAZ is an average of the base metal and weld metal toughness. These test results indicate that there is a significant reduction in the initiation fracture toughness as a result of welding. The second phase of this task dealt with the fracture toughness testing of 4-inch diameter 304 stainless steel pipes containing a gas tungsten arc weld. The pipes were tested at 550 0 F in four point bending. Three tests were performed, two with a through wall flaw growing circumferentially and the third pipe had a part through radial flaw in combination with the circumferential flaw. These tests were performed using unloading compliance and d.c. potential drop crack length estimate methods. The results of these tests indicate that the presence of a complex crack (radial and circumferential) reduces in the initiation toughness and the tearing modulus of the pipe material compared to a pipe with only a circumferentially growing crack. (orig.)

Elastic-plastic analysis of local and integral straining behaviour in a cracked plate

International Nuclear Information System (INIS)

Grueter, L.; Ruettenauer, B.

1982-01-01

For components of the primary coolant system of the German LMFBR prototype reactor SNR-300, integrity against anticipated accidents (Bethe-Tait) has to be shown for a cracked structure. Within this programme a number of tests with cracked wide plate specimens yielding overall limit strains of approximately 15% have been run; finite element calculations have been infinated for the wide plate geometry. The paper discusses the straining behaviour of a cracked plate by considering the numerical simulation of structures strained up to such high levels. The stress-strain diagram of the weldment of the austenitic stainless steel X6 CrNi 18 at 450 0 C has been used. Plane strain and stress conditions have been prescribed. The original plate dimensions (t = thickness = 40 mm; h = height = 400 mm) have been used as well as a similar, but smaller plate of t = 8.8 mm width. The crack length is defined as 0.1 t. The results show that for a cracked plate under high plastic strain the near-crack-tip-field values still govern the structural mechanical behaviour. Concerning the absolute dimensions the effects known for elasticity retain their influence in the plastic regime; however, the crack location becomes more unimportant with increasing strain, i.e. the appropriate pure geometry factor tends to unity in the plastic regime. The center-crack, defined as 2a = 0.1 t, corresponds to an equivalent edge crack of depth a = 0.05 t in the elastic case. It can be shown that for high plastic strains this correspondence remains fully valid. (orig.)

Structural health monitoring of glass/epoxy composite plates with MEMS PMN-PT sensors

Science.gov (United States)

Simon, Brenton R.; Tang, Hong-Yue; Horsley, David A.; La Saponara, Valeria; Lestari, Wahyu

2009-03-01

Sensors constructed with single-crystal PMN-PT, i.e. Pb(Mg1/3Nb2/3)O3-PbTiO3 or PMN, are developed in this paper for structural health monitoring of composite plates. To determine the potential of PMN-PT for this application, glass/epoxy composite specimens were created containing an embedded delamination-starter. Two different piezoelectric materials were bonded to the surface of each specimen: PMN-PT, the test material, was placed on one side of the specimen, while a traditional material, PZT-4, was placed on the other. A comparison of the ability of both materials to transmit and receive an ultrasonic pulse was conducted, with the received signal detected by both a second surface-bonded transducer constructed of the same material, as well as a laser Doppler vibrometer (LDV) analyzing the same location. The optimal frequency range of both sets of transducers is discussed and a comparison is presented of the experimental results to theory. The specimens will be fatigued until failure with further data collected every 3,000 cycles to characterize the ability of each material to detect the growing delamination in the composite structure. This additional information will be made available during the conference.

A unified nonlocal strain gradient plate model for nonlinear axial instability of functionally graded porous micro/nano-plates reinforced with graphene platelets

Science.gov (United States)

Sahmani, Saeid; Aghdam, Mohammad Mohammadi; Rabczuk, Timon

2018-04-01

By gradually changing of the porosity across a specific direction, functionally graded porous materials (FGPMs) are produced which can impart desirable mechanical properties. To enhance these properties, it is common to reinforce FGPMs with nanofillers. The main aim of the current study is to investigate the size-dependent nonlinear axial postbuckling characteristics of FGPM micro/nano-plates reinforced with graphene platelets. For this purpose, the theory of nonlocal strain gradient elasticity incorporating the both stiffness reduction and stiffness enhancement mechanisms of size effects is applied to the refined exponential shear deformation plate theory. Three different patterns of porosity dispersion across the plate thickness in conjunction with the uniform one are assumed for FGPM as an open-cell metal foam is utilized associated with the coefficients of the relative density and porosity. With the aid of the virtual work’s principle, the non-classical governing differential equations are constructed. Thereafter, an improved perturbation technique is employed to capture the size dependencies in the nonlinear load-deflection and load-shortening responses of the reinforced FGPM micro/nano-plates with and without initial geometric imperfection. It is indicated that by increasing the value of porosity coefficient, the size-dependent critical buckling loads of reinforced FGPM micro/nano-plates with all types of porosity dispersion pattern reduce, but the associated shortening may increase or decrease which depends on the type of dispersion pattern.

Development of reconstitution technique of irradiated specimens. 3. Report for FY 1995 and FY 1996 on JAERI-IHI cooperated research program (joint research)

Energy Technology Data Exchange (ETDEWEB)

Nishiyama, Yutaka; Fukaya, Kiyoshi; Onizawa, Kunio; Suzuki, Masahide [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakamura, Terumi; Kaihara, Shoichiro; Yoshida, Kazuo; Sato, Akira

1998-10-01

The cooperated research between Japan Atomic Energy Research Institute and Ishikawajima-Harima Heavy Industries Co., Ltd. on the development of reconstitution technique of irradiated reactor pressure vessel surveillance specimens has been performed from FY 1993. In FY 1993-1994, the method of surface activated joining (SAJ) was applied to reconstitution of Charpy impact specimens. Some verification tests using unirradiated reactor pressure vessel plate materials have shown that SAJ is feasible for a reconstitution technique, in particular, owing to low joining temperature. The present paper reports the results of the cooperated research performed in FY 1995-1996. To improve the quality of the SAJ, the configuration of the end tab surface to be joined with the insert material was modified. The torque measured during joining was also introduced in joining parameters. A nondestructive inspection, temperature measurements in the specimens during joining were performed. The effect of joining on Charpy impact properties was discussed. For practical application of the technique to irradiated specimens, we confirmed that the impact specimens with joining interface gave rise to no failure at the joining position during impact test after neutron irradiation. (author)

Production of atmospheric pressure diffuse nanosecond pulsed dielectric barrier discharge using the array needles-plate electrode in air

International Nuclear Information System (INIS)

Yang Dezheng; Wang Wenchun; Jia Li; Nie Dongxia; Shi Hengchao

2011-01-01

In this paper, a bidirectional high pulse voltage with 20 ns rising time is employed to generate an atmospheric pressure diffuse dielectric barrier discharge using the array needles-plate electrode configuration. Both double needle and multiple needle electrode configurations nanosecond pulsed dielectric barrier discharges are investigated. It is found that a diffuse discharge plasma with low gas temperature can be obtained, and the plasma volume increases with the increase of the pulse peak voltage, but remains almost constant with the increase of the pulse repetition rate. In addition to showing the potential application on a topographically nonuniform surface treatment of the discharge, the multiple needle-plate electrode configuration with different needle-plate electrode gaps are also employed to generate diffuse discharge plasma.

FRACTURE MECHANICS APPROACH TO ESTIMATE FATIGUE LIVES OF WELDED LAP-SHEAR SPECIMENS

Energy Technology Data Exchange (ETDEWEB)

Lam, P.; Michigan, J.

2014-04-25

A full range of stress intensity factor solutions for a kinked crack is developed as a function of weld width and the sheet thickness. When used with the associated main crack solutions (global stress intensity factors) in terms of the applied load and specimen geometry, the fatigue lives can be estimated for the laser-welded lap-shear specimens. The estimations are in good agreement with the experimental data. A classical solution for an infinitesimal kink is also employed in the approach. However, the life predictions tend to overestimate the actual fatigue lives. The traditional life estimations with the structural stress along with the experimental stress-fatigue life data (S-N curve) are also provided. In this case, the estimations only agree with the experimental data under higher load conditions.

Radiation shielding plate

International Nuclear Information System (INIS)

Kobayashi, Torakichi; Sugawara, Takeo.

1983-01-01

Purpose: To reduce the weight and stabilize the configuration of a radiation shielding plate which is used in close contact with an object to be irradiated with radiation rays. Constitution: The radiation shielding plate comprises a substrate made of lead glass and a metallic lead coating on the surface of the substrate by means of plating, vapor deposition or the like. Apertures for permeating radiation rays are formed to the radiation shielding plate. Since the shielding plate is based on a lead glass plate, a sufficient mechanical strength can be obtained with a thinner structure as compared with the conventional plate made of metallic lead. Accordingly, if the shielding plate is disposed on a soft object to be irradiated with radiation rays, the object and the plate itself less deform to obtain a radiation irradiation pattern with distinct edges. (Moriyama, K.)

Plating on difficult-to-plate metals: what's new

International Nuclear Information System (INIS)

Wiesner, H.J.

1980-01-01

Some of the changes since 1970 in procedures for plating on such materials as titanium, molybdenum, silicon, aluminum, and gallium arsenide are summarized. While basic procedures for plating some of these materials were developed as many as 30 to 40 years ago, changes in the end uses of the plated products have necessitated new plating processes. In some cases, vacuum techniques - such as ion bombardment, ion implantation, and vacuum metallization - have been introduced to improve the adhesion of electrodeposits. In other cases, these techniques have been used to deposit materials upon which electrodeposits are required

Effect of plate shapes in orifice plate type flowmeters

International Nuclear Information System (INIS)

Moeller, S.V.

1984-01-01

The study of unusual plate shapes in orifice plate type flowmeters is presented, with a view to providing data for the substitution of the plate with one centered circular orifice in those applications where its use is not possible. For this purpose, six pairs of plates with different forms, with and without chamfered edges, were made and tested in a closed water loop. Results show that, generally, the use of chamfers improves the results and, in the case of perforated and slotlike orificed plates, the narrow-ness of the fluid passage tends to make unnecessary its use. (Author) [pt

Plating laboratory

International Nuclear Information System (INIS)

Seamster, A.G.; Weitkamp, W.G.

1984-01-01

The lead plating of the prototype resonator has been conducted entirely in the plating laboratory at SUNY Stony Brook. Because of the considerable cost and inconvenience in transporting personnel and materials to and from Stony Brook, it is clearly impractical to plate all the resonators there. Furthermore, the high-beta resonator cannot be accommodated at Stony Brook without modifying the set up there. Consequently the authors are constructing a plating lab in-house

Fixed-angle plates in patella fractures - a pilot cadaver study

Directory of Open Access Journals (Sweden)

Wild M

2011-01-01

Full Text Available Abstract Objective Modified anterior tension wiring with K-wires and cannulated lag screws with anterior tension wiring are currently the fixation of choice for patellar fractures. Failure of fixation, migration of the wires, postoperative pain and resulting revision surgery, however, are not uncommon. After preliminary biomechanical testing of a new fixed-angle plate system especially designed for fixation of patella fractures the aim of this study was to evaluate the surgical and anatomical feasibility of implanting such a plate-device at the human patella. Methods In six fresh unfixed female cadavers without history of previous fractures around the knee (average age 88.8 years a bilateral fixed-angle plate fixation of the patella was carried out after previous placement of a transverse central osteotomy. Operative time, intra-operative problems, degree of retropatellar arthritis (following Outerbridge, quality of reduction and existence of any intraarticular screw placement have been raised. In addition, lateral and anteroposterior radiographs of all specimens were made. Results Due to the high average age of 88.8 years no patella showed an unimpaired retropatellar articular surface and all were severely osteoporotic, which made a secure fixation of the reduction forceps during surgery difficult. The operation time averaged 49 minutes (range: 36-65. Although in postoperative X-rays the fracture gap between the fragments was still visible, the analysis of the retropatellar surface showed no residual articular step or dehiscence > 0.5 mm. Also in a total of 24 inserted screws not one intraarticular malposition was found. No intraoperative complications were noticed. Conclusions Osteosynthesis of a medial third patella fracture with a bilateral fixed-angle plate-device is surgically and anatomically feasible without difficulties. Further studies have to depict whether the bilateral fixed-angle plate-osteosynthesis of the patella displays

Embrittlement and annealing of reactor pressure vessel steels: comparison of BR3 surveillance and vessel plates to the surrogate plates representative of the Yankee Rowe vessel

International Nuclear Information System (INIS)

Fabry, A.; Chaouadi, T.; Puzzolante, J.L.; Van de Velde, J.; Biemiller, E.C.; Rossinski, S.T.; Carter, R.G.

1996-07-01

The sister pressure vessels at the BR3 and Rowe Yankee PWR plants were operated at a lower-than-usual temperature (260 degrees Celsius) and their plates were austenitized at higher-than-usual temperature (970 degrees Celsius). A heat tratemement leading to a coarser microstructure than typical for the fine grain plates that are considered in development of USNRC Regulatory guide 1.99. This material displayed outlier behaviour charackterized by a 41J CVN-shift significantly larger than predicted by Regulatory Guide 1.99. Because lower radiation temperature and nickell alloying are generally considered detrimental to irradiation sensitivity, there was a major concern that the nickel-modified lower Rowe plate and the nickel-modified BR3 plate may become too embrittled to satisfy the toughness requirements enbodied in the PTS screening criterion. This paper compares three complementary studies undertaken to clarify these uncertainties: 1) the accelerated irradiation and test program launched in 1990 by Yankee Atomic Electric Company using typical vessel plate materials containing 0.24% copper at two nickel levels: YA1, 0.63% (A533-B) and YA9, 0.19% (A302-B). These were heat-treated to produce the coarse and fine grain microstructures representative of the Yankee/BR3 and the Regulatory Guide plates, respectively, 2) the BR3 surveillance and vessel testing program: this vessel was wet-annealed in 1984, relicensed for operation till the plant shutdown in 1987, ANCL was trepanned in early 1995, 3) the accelerated irradiations in the Belgian BR2 test reactor of the Yankee coarse grain plates YA1 and YA9 together with BR3 vessel specimens extracted at nozzle elevation, a location with negligible radiation exposure. It is shown that the PTS screening criterion was never attained by the BR3 and Rowe plates, and that the BR3 vessel anneal was neither necessary nor sufficient. Finally, the sensitivity of embrittlement, annealing and post-annealing reembrittlement to irradiation

Embrittlement and annealing of reactor pressure vessel steels: comparison of BR3 surveillance and vessel plates to the surrogate plates representative of the Yankee Rowe vessel

Energy Technology Data Exchange (ETDEWEB)

Fabry, A.; Chaouadi, T.; Puzzolante, J.L.; Van de Velde, J. [Centre de l``Etude de l``Energie Nucleaire, Mol (Belgium); Biemiller, E.C. [Yankee Atomic Electric Company, Bolton (United States); Rossinski, S.T.; Carter, R.G. [Electric Power Research Institute, Charlotte (United States)

1996-07-01

The sister pressure vessels at the BR3 and Rowe Yankee PWR plants were operated at a lower-than-usual temperature (260 degrees Celsius) and their plates were austenitized at higher-than-usual temperature (970 degrees Celsius). A heat tratemement leading to a coarser microstructure than typical for the fine grain plates that are considered in development of USNRC Regulatory guide 1.99. This material displayed outlier behaviour charackterized by a 41J CVN-shift significantly larger than predicted by Regulatory Guide 1.99. Because lower radiation temperature and nickell alloying are generally considered detrimental to irradiation sensitivity, there was a major concern that the nickel-modified lower Rowe plate and the nickel-modified BR3 plate may become too embrittled to satisfy the toughness requirements enbodied in the PTS screening criterion. This paper compares three complementary studies undertaken to clarify these uncertainties: 1) the accelerated irradiation and test program launched in 1990 by Yankee Atomic Electric Company using typical vessel plate materials containing 0.24% copper at two nickel levels: YA1, 0.63% (A533-B) and YA9, 0.19% (A302-B). These were heat-treated to produce the coarse and fine grain microstructures representative of the Yankee/BR3 and the Regulatory Guide plates, respectively, 2) the BR3 surveillance and vessel testing program: this vessel was wet-annealed in 1984, relicensed for operation till the plant shutdown in 1987, ANCL was trepanned in early 1995, 3) the accelerated irradiations in the Belgian BR2 test reactor of the Yankee coarse grain plates YA1 and YA9 together with BR3 vessel specimens extracted at nozzle elevation, a location with negligible radiation exposure. It is shown that the PTS screening criterion was never attained by the BR3 and Rowe plates, and that the BR3 vessel anneal was neither necessary nor sufficient. Finally, the sensitivity of embrittlement, annealing and post-annealing reembrittlement to irradiation

Janka hardness using nonstandard specimens

Science.gov (United States)

David W. Green; Marshall Begel; William Nelson

2006-01-01

Janka hardness determined on 1.5- by 3.5-in. specimens (2×4s) was found to be equivalent to that determined using the 2- by 2-in. specimen specified in ASTM D 143. Data are presented on the relationship between Janka hardness and the strength of clear wood. Analysis of historical data determined using standard specimens indicated no difference between side hardness...

Transfer plate radioassay using cell monolayers to detect anti-cell surface antibodies synthesized by lymphocyte hybridomas

International Nuclear Information System (INIS)

Schneider, M.D.; Eisenbarth, G.S.

1979-01-01

A solid phase [ 125 I] Protein A radioassay for anti-cell surface antibodies is described, which employs target cell monolayers cultured on fenestrated polyvinyl chloride 96-well plates ('transfer plates'). The calibrated aperture in the bottom of each well is small enough to retain fluid contents by surface tension during monolayer growth, but also permits fluid to enter the wells when transfer plate are lowered into receptacles containing washing buffer on test sera. To assay for antibodies directed against target cell surface antigens, transfer plates bearing monolayers are inserted into microculture plates with corresponding 96-well geometry, thereby simultaneously sampling 96 wells. This assay allows rapid screening of hundreds of hybrid cell colonies for production of antibodies with desired tissue specificity. (Auth.)

Distance from the growth plate and Its relation to the outcome of unicameral bone cyst treatment.

Science.gov (United States)

Haidar, Saadallah George; Culliford, David J; Gent, Edward David; Clarke, Nicholas M P

2011-04-01

Interventions to treat unicameral bone cysts vary. Nonetheless, regardless of the intervention modality, the outcome is not certain. The purpose of this study was to determine if the distance between the growth plate and the cyst can be used to predict the outcome of the treatment. Retrospectively, we assessed the outcome of 39 interventions in nineteen children that were performed between 1994 and 2003. Seventeen different modalities of treatment were employed. There were three female and sixteen male patients. The average age was 8 years. Nine cysts were in the greater trochanter area, three were in the femoral capital area and seven were in the proximal humerus. According to the cyst's distance from the growth plate, at the intervention time, there were 18 cases within less than 2 cm and 21 cases of more than 2 cm. Complete healing was achieved in 10 children (employing seven different modalities). In nine of them, the cysts were more than 2 cm away from the growth plate. In one child, the cyst was within less than 2 cm of the growth plate, however, treatment here involved epiphyseodesis. This study confirmed that, regardless of intervention modality, complete healing was not achievable in those cysts that are within less than 2 cm of an active growth plate. Complete healing was possible in those cysts that are more than 2 cm away from the growth plate. The 2-cm distance from the growth plate could be used as a predictor of treatment outcome of unicameral bone cysts.

LPTR irradiation of LLL vanadium tensile specimens and LLL Nb--1Zr tensile specimens

International Nuclear Information System (INIS)

MacLean, S.C.; Rowe, C.L.

1977-01-01

The LPTR irradiation of 14 LLL vanadium tensile specimens and 14 LLL Nb-1Zr tensile specimens is described. Sample packaging, the irradiation schedule and neutron fluences for three energy ranges are given

Create Your Plate

Medline Plus

Full Text Available ... Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective ... foods within each food category. Try these seven steps to get started: Using your dinner plate, put ...

Georeferencing Animal Specimen Datasets

NARCIS (Netherlands)

van Erp, M.G.J.; Hensel, R.; Ceolin, D.; van der Meij, M.

2014-01-01

For biodiversity research, the field of study that is concerned with the richness of species of our planet, it is of the utmost importance that the location of an animal specimen find is known with high precision. Due to specimens often having been collected over the course of many years, their

Virtual haptic system for intuitive planning of bone fixation plate placement

Directory of Open Access Journals (Sweden)

Kup-Sze Choi

2017-01-01

Full Text Available Placement of pre-contoured fixation plate is a common treatment for bone fracture. Fitting of fixation plates on fractured bone can be preoperatively planned and evaluated in 3D virtual environment using virtual reality technology. However, conventional systems usually employ 2D mouse and virtual trackball as the user interface, which makes the process inconvenient and inefficient. In the paper, a preoperative planning system equipped with 3D haptic user interface is proposed to allow users to manipulate the virtual fixation plate intuitively to determine the optimal position for placement on distal medial tibia. The system provides interactive feedback forces and visual guidance based on the geometric requirements. Creation of 3D models from medical imaging data, collision detection, dynamics simulation and haptic rendering are discussed. The system was evaluated by 22 subjects. Results show that the time to achieve optimal placement using the proposed system was shorter than that by using 2D mouse and virtual trackball, and the satisfaction rating was also higher. The system shows potential to facilitate the process of fitting fixation plates on fractured bones as well as interactive fixation plate design.

Neutron radiography of thick hydrogenous materials with use of an imaging plate neutron detector

International Nuclear Information System (INIS)

Kato, K.; Matsumoto, G.; Karasawa, Y.; Niimura, N.; Matsubayashi, M.; Tsuruno, A.

1996-01-01

The value of the neutron mass attenuation coefficient of hydrogen being very high, it is extremely difficult to image normal size, living animals with neutron radiography. However, the authors suggest the possibility of applying neutron radiography for biomedical specimens. The organs in the breast, bones and cartilages in the extremities, and the tail of mice and rats were clearly imaged by neutron radiography with Gd foils as neutron converters and X-ray films. However, no contours of the organs in the mouse abdomen were visible with neutron radiography with an exposure time of 200 s. By adding Gd or Li compounds as neutron converters to imaging X-ray plates, imaging plates have been developed for neutron detectors. A trial using these imaging plates for neutron radiography of water-filled containers and the abdomen of mice was completed. The roundness of a 100 ml-beaker was imaged with a neutron exposure of 180 s. Obscure contours of the liver and kidneys of the mouse were imaged with a neutron exposure of 100 s. (orig.)

Effects of finite element formulation on optimal plate and shell structural topologies

CSIR Research Space (South Africa)

Long, CS

2009-09-01

Full Text Available , and the other is a 4-node element accounting for in-plane (drilling) rotations. Plate elements selected for evaluation include the discrete Kirchhoff quadrilateral (DKQ) element and two Mindlin–Reissner-based elements, one employing selective reduced integration...

First evaluation of automated specimen inoculation for wound swab samples by use of the Previ Isola system compared to manual inoculation in a routine laboratory: finding a cost-effective and accurate approach.

Science.gov (United States)

Mischnik, Alexander; Mieth, Markus; Busch, Cornelius J; Hofer, Stefan; Zimmermann, Stefan

2012-08-01

Automation of plate streaking is ongoing in clinical microbiological laboratories, but evaluation for routine use is mostly open. In the present study, the recovery of microorganisms from the Previ Isola system plated polyurethane (PU) swab samples is compared to manually plated control viscose swab samples from wounds according to the CLSI procedure M40-A (quality control of microbiological transport systems). One hundred twelve paired samples (224 swabs) were analyzed. In 80/112 samples (71%), concordant culture results were obtained with the two methods. In 32/112 samples (29%), CFU recovery of microorganisms from the two methods was discordant. In 24 (75%) of the 32 paired samples with a discordant result, Previ Isola plated PU swabs were superior. In 8 (25%) of the 32 paired samples with a discordant result, control viscose swabs were superior. The quality of colony growth on culture media for further investigations was superior with Previ Isola inoculated plates compared to manual plating techniques. Gram stain results were concordant between the two methods in 62/112 samples (55%). In 50/112 samples (45%), the results of Gram staining were discordant between the two methods. In 34 (68%) of the 50 paired samples with discordant results, Gram staining of PU swabs was superior to that of control viscose swabs. In 16 (32%) of the 50 paired samples, Gram staining of control viscose swabs was superior to that of PU swabs. We report the first clinical evaluation of Previ Isola automated specimen inoculation for wound swab samples. This study suggests that use of an automated specimen inoculation system has good results with regard to CFU recovery, quality of Gram staining, and accuracy of diagnosis.

DNA extraction from herbarium specimens.

Science.gov (United States)

Drábková, Lenka Záveská

2014-01-01

With the expansion of molecular techniques, the historical collections have become widely used. Studying plant DNA using modern molecular techniques such as DNA sequencing plays an important role in understanding evolutionary relationships, identification through DNA barcoding, conservation status, and many other aspects of plant biology. Enormous herbarium collections are an important source of material especially for specimens from areas difficult to access or from taxa that are now extinct. The ability to utilize these specimens greatly enhances the research. However, the process of extracting DNA from herbarium specimens is often fraught with difficulty related to such variables as plant chemistry, drying method of the specimen, and chemical treatment of the specimen. Although many methods have been developed for extraction of DNA from herbarium specimens, the most frequently used are modified CTAB and DNeasy Plant Mini Kit protocols. Nine selected protocols in this chapter have been successfully used for high-quality DNA extraction from different kinds of plant herbarium tissues. These methods differ primarily with respect to their requirements for input material (from algae to vascular plants), type of the plant tissue (leaves with incrustations, sclerenchyma strands, mucilaginous tissues, needles, seeds), and further possible applications (PCR-based methods or microsatellites, AFLP).

New gas mixtures for Resistive Plate Chambers operated in avalanche mode

Energy Technology Data Exchange (ETDEWEB)

Abbrescia, M [Dipartimento Interateneo di Fisica, Universita di Bari and sezione INFN, via Amendola 173, I-70126 Bari (Italy); Cassano, V; Nuzzo, S; Piscitelli, G; Vadruccio, D; Zaza, S [Dipartimento Interateneo di Fisica, Universita di Bari and sezione INFN, via Amendola 173, I-70126 Bari (Italy)

2012-01-01

The possibility of using gas mixtures containing Helium, to overcome some of the problems encountered with standard gas mixture employed up to now for Resistive Plate Chambers, is studied here. New and interesting experimental results are reported, opening a possible original path of investigation in this field.

Calibration of BAS-TR image plate response to high energy (3-300 MeV) carbon ions

Science.gov (United States)

Doria, D.; Kar, S.; Ahmed, H.; Alejo, A.; Fernandez, J.; Cerchez, M.; Gray, R. J.; Hanton, F.; MacLellan, D. A.; McKenna, P.; Najmudin, Z.; Neely, D.; Romagnani, L.; Ruiz, J. A.; Sarri, G.; Scullion, C.; Streeter, M.; Swantusch, M.; Willi, O.; Zepf, M.; Borghesi, M.

2015-12-01

The paper presents the calibration of Fuji BAS-TR image plate (IP) response to high energy carbon ions of different charge states by employing an intense laser-driven ion source, which allowed access to carbon energies up to 270 MeV. The calibration method consists of employing a Thomson parabola spectrometer to separate and spectrally resolve different ion species, and a slotted CR-39 solid state detector overlayed onto an image plate for an absolute calibration of the IP signal. An empirical response function was obtained which can be reasonably extrapolated to higher ion energies. The experimental data also show that the IP response is independent of ion charge states.

Modeling of high-density U-MO dispersion fuel plate performance

International Nuclear Information System (INIS)

Hayes, S.L.; Meyer, M.K.; Hofman, G.L.; Rest, J.; Snelgrove, J.L.

2002-01-01

Results from postirradiation examinations (PIE) of highly loaded U-Mo/Al dispersion fuel plates over the past several years have shown that the interaction between the metallic fuel particles and the matrix aluminum can be extensive, reducing the volume of the high-conductivity matrix phase and producing a significant volume of low-conductivity reaction-product phase. This phenomenon results in a significant decrease in fuel meat thermal conductivity during irradiation. PIE has further shown that the fuel-matrix interaction rate is a sensitive function of irradiation temperature. The interplay between fuel temperature and fuel-matrix interaction makes the development of a simple empirical correlation between the two difficult. For this reason a comprehensive thermal model has been developed to calculate temperatures throughout the fuel plate over its lifetime, taking into account the changing volume fractions of fuel, matrix and reaction-product phases within the fuel meat owing to fuel-matrix interaction; this thermal model has been incorporated into the dispersion fuel performance code designated PLATE. Other phenomena important to fuel thermal performance that are also treated in PLATE include: gas generation and swelling in the fuel and reaction-product phases, incorporation of matrix aluminum into solid solution with the unreacted metallic fuel particles, matrix extrusion resulting from fuel swelling, and cladding corrosion. The phenomena modeled also make possible a prediction of fuel plate swelling. This paper presents a description of the models and empirical correlations employed within PLATE as well as validation of code predictions against fuel performance data for U-Mo experimental fuel plates from the RERTR-3 irradiation test. (author)

Investigating the effect of clamping force on the fatigue life of bolted plates using volumetric approach

International Nuclear Information System (INIS)

Esmaeili, F.; Chakherlou, T. N.; Zehsaz, M.; Hasanifard, S.

2013-01-01

In this paper, the effects of bolt clamping force on the fatigue life for bolted plates made from Al7075-T6 have been studied on the values of notch strength reduction factor obtained by volumetric approach. To attain stress distribution around the notch (hole) which is required for volumetric approach, nonlinear finite element simulations were carried out. To estimate the fatigue life, the available smooth S-N curve of Al7075-T6 and the notch strength reduction factor obtained from volumetric method were used. The estimated fatigue life was compared with the available experimental test results. The investigation shows that there is a good agreement between the life predicted by the volumetric approach and the experimental results for various specimens with different amount of clamping forces. Volumetric approach and experimental results showed that the fatigue life of bolted plates improves because of the compressive stresses created around the plate hole due to clamping force.

Cohesive traction-separation relations for plate tearing under mixed mode loading

DEFF Research Database (Denmark)

Andersen, R. G.; Woelke, P. B.; Nielsen, K. L.

2018-01-01

The present study investigates a sequence of failure events related to steady-state tearing of large-scale ductile plates by employing the micro-mechanics based Gurson-Tvergaard-Needleman (GTN) model. The fracture process in front of an advancing crack is approximated by a series of 2D plane strain...... finite element models to facilitate a comprehensive study of mixed mode fracture behavior as well as a parameter study of the cohesive energy and tractions involved in the process. The results from the conducted GTN model simulations are used to define cohesive zone models suitable for plate tearing...

New Procedure for Compacting Prismatic Specimens of Cement-Treated Base Materials

Directory of Open Access Journals (Sweden)

Alaitz Linares-Unamunzaga

2018-06-01

Full Text Available Understanding the long-term behaviour of cement-treated base materials is a key factor to improve its design and obtain environmentally friendly pavement base materials. Their characterization requires manufacturing prismatic specimens. However, various authors highlight the absence of standardized test methods for fabricating beams in the field and laboratory, which is not an easy task because it depends on the qualification and experience of the testing team. The aim of this paper is to present a new device and procedure for compacting prismatic specimens of cement-treated base materials. In this research, it was used for compacting soil-cement to simulate its performance as a road base material. This device employs elements that are generally available in a concrete laboratory test, such as a vibrating table or prismatic moulds. Once the procedure was established, and in order to verify its suitability, flexural and compressive strength tests were carried out. Results showed that the values obtained were consistent with this material and, despite the heterogeneity of the material, specimens from the same batch provided similar results and, hence, validated the compaction process. This new compacting procedure can improve understanding of the long-term performance of cement-treated materials from flexural and fatigue tests.

Measurement of specimen-induced aberrations of biological samples using phase stepping interferometry.

Science.gov (United States)

Schwertner, M; Booth, M J; Neil, M A A; Wilson, T

2004-01-01

Confocal or multiphoton microscopes, which deliver optical sections and three-dimensional (3D) images of thick specimens, are widely used in biology. These techniques, however, are sensitive to aberrations that may originate from the refractive index structure of the specimen itself. The aberrations cause reduced signal intensity and the 3D resolution of the instrument is compromised. It has been suggested to correct for aberrations in confocal microscopes using adaptive optics. In order to define the design specifications for such adaptive optics systems, one has to know the amount of aberrations present for typical applications such as with biological samples. We have built a phase stepping interferometer microscope that directly measures the aberration of the wavefront. The modal content of the wavefront is extracted by employing Zernike mode decomposition. Results for typical biological specimens are presented. It was found for all samples investigated that higher order Zernike modes give only a small contribution to the overall aberration. Therefore, these higher order modes can be neglected in future adaptive optics sensing and correction schemes implemented into confocal or multiphoton microscopes, leading to more efficient designs.

Specimen size effects in Charpy impact testing

International Nuclear Information System (INIS)

Alexander, D.J.; Klueh, R.L.

1989-01-01

Full-size , half-size, and third-size specimens from several different steels have been tested as part of an ongoing alloy development program. The smaller specimens permit more specimens to be made from small trail heats and are much more efficient for irradiation experiments. The results of several comparisons between the different specimen sizes have shown that the smaller specimens show qualitatively similar behavior to large specimens, although the upper-shelf energy level and ductile-to-ductile transition temperature are reduced. The upper-shelf energy levels from different specimen sizes can be compared by using a simple volume normalization method. The effect of specimen size and geometry on the ductile-to-ductile transition temperature is more difficult to predict, although the available data suggest a simple shift in the transition temperature due to specimen size changes.The relatively shallower notch used in smaller specimens alters the deformation pattern, and permits yielding to spread back to the notched surface as well as through to the back. This reduces the constraint and the peak stresses, and thus the initiation of cleavage is more difficult. A better understanding of the stress and strain distributions is needed. 19 refs., 3 figs., 3 tabs

Paper microzone plates.

Science.gov (United States)

Carrilho, Emanuel; Phillips, Scott T; Vella, Sarah J; Martinez, Andres W; Whitesides, George M

2009-08-01

This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multiwell plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (approximately 180 microm), require small volumes of sample (5 microL per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (approximately 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was approximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader.

Effects of annealing and pulse plating on soft magnetic properties of electroplated Fe-Ni films

Directory of Open Access Journals (Sweden)

T. Yanai

2016-05-01

Full Text Available We have already reported that Fe-Ni films prepared in citric-acid-based plating baths show good soft magnetic properties. In this paper, we investigated the effect of the grain size of the Fe-Ni crystalline phase in the films on magnetic properties, and employed an annealing and a pulse plating method in order to vary the grain size. The coercivity of the annealed Fe-Ni films at 600 °C shows large value, and good correlation between the grain growth and the coercivity was observed. The pulse plating enables us to reduce the grain size of the as-plated Fe-Ni films compared with the DC plating method, and we realized smooth surface and low coercivity of the Fe-Ni films using the pulse plating method. From these results, we confirmed the importance of the reduction in the grain size, and concluded that a pulse plating is an effective method to improve the good soft magnetic properties for our previously-reported Fe-Ni films.

Transfer plate radioassay using adsorbed anti-insulin antibody to detect insulin secreted by islet cell cultures

International Nuclear Information System (INIS)

Scearce, R.M.; Oie, H.K.; Gazdar, A.F.; Chick, W.L.; Eisenbarth, G.S.

1981-01-01

A solid-phase radioimmunoassay for detection of insulin synthesized by islet cell clones is described. This assay employs anti-insulin antibody adsorbed onto fenestrated polyvinyl chloride 96-well plates ('transfer plates'). The calibrated aperture in the bottom of each transfer plate well permits fluid to enter the wells when transfer plates are lowered into microculture wells containing insulin. With this assay it is possible to rapidly screen hundreds of islet cell cultures for insulin production. The authors have used this assay to facilitate cloning of the RIN rat insulinoma cell line. The assay readily detects insulin synthesis by RIN cells and [ 125 I]insulin is not displaced by culture medium from cells which do not produce insulin. The transfer plate format should be applicable to semiautomate other radioimmunoassays. (Auth.)

VIBRATION CONTROL OF RECTANGULAR CROSS-PLY FRP PLATES USING PZT MATERIALS

Directory of Open Access Journals (Sweden)

DILEEP KUMAR K

2017-12-01

Full Text Available Piezoelectric materials are extensively employed in the field of structures for condition monitoring, smart control and testing applications. The piezoelectric patches are surface bonded to a composite laminate plate and used as vibration actuators. The coupling effects between the mechanical and electric properties of piezoelectric materials have drawn significant attention for their potential applications. In the present work, an analytical solution of the vibration response of a simply supported laminate rectangular plate under time harmonic electrical loading is obtained and a concept is developed for an approximate dynamic model to the vibration response of the simply supported orthotropic rectangular plates excited by a piezoelectric patch of variable rectangular geometry and location. A time harmonic electric voltages with the same magnitude and opposite sign are applied to the two symmetric piezoelectric actuators, which results in the bending moment on the plate. The main objective of the work is to obtain an analytical solution for the vibration amplitude of composite plate predicted from plate theory. The results demonstrate that the vibration modes can be selectively excited and the geometry of the PZTactuator shape remarkably affects the distribution of the response among modes. Thus according to the desired degree shape control it is possible to tailor the shape, size and properly designed control algorithm of the actuator to either excite or suppress particular modes.

Investigation on effect of laser shock processing on fatigue crack initiation and its growth in aluminum alloy plate

International Nuclear Information System (INIS)

Zhang, X.Q.; Li, H.; Yu, X.L.; Zhou, Y.; Duan, S.W.; Li, S.Z.; Huang, Z.L.; Zuo, L.S.

2015-01-01

Highlights: • LSP can greatly delay crack formation. • The micro-crack growing processes and its fracture are showed clearly. • Surface topographies and crack initiation locations are displayed. - Abstract: A series of contrasting experiments were carried out to examine the effects of laser shock processing (LSP) on fatigue properties of slot in 7075-T6 aluminum alloy plate. Both side surfaces of slot were subjected to LSP. The surface topographies were observed and the residual stresses were tested. The treated and the un-treated specimens were pulled by the fatigue cyclic loading respectively. The fatigue crack propagating processes were recorded, and the fatigue fracture microscopic morphologies were analyzed by scanning electron microscope (SEM). Experimental results and analyses show that LSP induces micro-dent on surface and squeezes the compressive residual stresses into surface layer of specimen. It can remarkably delay the micro-crack formation, and transfer the location of fatigue crack initiation from top surface to sub-surface. The spacing of fatigue striations on the treated specimen fatigue fracture obviously decreases. Therefore, the fatigue life of specimen after LSP treatment significantly increases

Development of Reconstitution Technology for Surveillance Specimens

International Nuclear Information System (INIS)

Yasushi Atago; Shunichi Hatano; Eiichiro Otsuka

2002-01-01

The Japan Power Engineering and Inspection Corporation (JAPEIC) has been carrying out the project titled 'Nuclear Power Plant Integrated Management Technology (PLIM)' consigned by Japanese Ministry of Economy, Trade and Industry (METI) since 1996FY as a 10-years project. As one of the project themes, development of reconstitution technology for reactor pressure vessel (RPV/RV) surveillance specimens, which are installed in RPVs to monitor the neutron irradiation embrittlement on RPV/RV materials, is now on being carried out to deal with the long-term operation of nuclear power plants. The target of this theme is to establish the technical standard for applicability of reconstituted surveillance specimens including the reconstitution of the Charpy specimens and Compact Tension (CT) specimens. With the Charpy specimen reconstitution, application of 10 mm length inserts is used, which enables the conversion of tests from the LT-direction to the TL-direction. This paper presents the basic data from Charpy and CT specimens of RPV materials using the surveillance specimens obtained for un-irradiated materials including the following. 1) Reconstitution Technology of Charpy Specimens. a) The interaction between plastic zone and Heat Affected Zone (HAZ). b) The effects of the possible deviations from the standard specimens for the reconstituted specimens. 2) Reconstitution Technology of CT specimens. a) The correlation between fracture toughness and plastic zone width. Because the project is now in progress, this paper describes the outline of the results obtained as of the end of 2000 FY. (authors)

Experimental studies on the deformation and rupture of thin metal plates subject to underwater shock wave loading

Directory of Open Access Journals (Sweden)

Chen Pengwan

2015-01-01

Full Text Available In this paper, the dynamic deformation and rupture of thin metal plates subject to underwater shock wave loading are studied by using high-speed 3D digital image correlation (3D-DIC. An equivalent device consist of a gas gun and a water anvil tube was used to supplying an exponentially decaying pressure in lieu of explosive detonation which acted on the panel specimen. The thin metal plate is clamped on the end of the shock tube by a flange. The deformation and rupture process of the metal plates subject to underwater shock waves are recorded by two high-speed cameras. The shape, displacement fields and strain fields of the metal plates under dynamic loading are obtained by using VIC-3D digital image correlation software. The strain gauges also were used to monitor the structural response on the selected position for comparison. The DIC data and the strain gauges results show a high level of correlation, and 3D-DIC is proven to be an effective method to measure 3D full-field dynamic response of structures under underwater impact loading. The effects of pre-notches on the failure modes of thin circular plate were also discussed.

New AlGaN/GaN HEMTs employing both a floating gate and a field plate

International Nuclear Information System (INIS)

Lim, Jiyong; Choi, Young-Hwan; Kim, Young-Shil; Han, Min-Koo

2010-01-01

We designed and fabricated AlGaN/GaN high-electron-mobility transistors (HEMTs) employing both a floating gate (FG) and a field plate (FP), which increase the breakdown voltage of AlGaN/GaN HEMTs significantly without sacrificing forward electric characteristics. The electric field strength at the gate-drain region of the proposed AlGaN/GaN HEMT was reduced successfully due to an increase in the number of depletion region edges. The breakdown voltage of the proposed AlGaN/GaN HEMT was 1106 V, while those of the conventional devices with only an FP or FG were 688 and 828 V, respectively. The leakage current of the proposed AlGaN/GaN HEMTs was 1.68 μA under a reverse bias of -100 V while those of the conventional devices with only an FP or FG were 3.21 and 1.91 μA, respectively, under the same condition. The forward electric characteristics of the proposed and conventional AlGaN/GaN HEMTs are similar. The maximum drain current of the proposed AlGaN/GaN HEMTs was 344 mA mm -1 while those of the conventional devices with only an FP or FG were 350 and 357 mA mm -1 , respectively. The maximum transconductance of the proposed device was 102.9 mS mm -1 , while those of the conventional devices were 97.8 and 101.9 mS mm -1 . The breakdown voltage and the leakage current of the proposed device were improved considerably without sacrificing the forward electric characteristics. It should be noted that there were no additional processing steps and mask levels compared to the conventional FP process.

Quantitative X-ray microanalysis of biological specimens

International Nuclear Information System (INIS)

Roomans, G.M.

1988-01-01

Qualitative X-ray microanalysis of biological specimens requires an approach that is somewhat different from that used in the materials sciences. The first step is deconvolution and background subtraction on the obtained spectrum. The further treatment depends on the type of specimen: thin, thick, or semithick. For thin sections, the continuum method of quantitation is most often used, but it should be combined with an accurate correction for extraneous background. However, alternative methods to determine local mass should also be considered. In the analysis of biological bulk specimens, the ZAF-correction method appears to be less useful, primarily because of the uneven surface of biological specimens. The peak-to-local background model may be a more adequate method for thick specimens that are not mounted on a thick substrate. Quantitative X-ray microanalysis of biological specimens generally requires the use of standards that preferably should resemble the specimen in chemical and physical properties. Special problems in biological microanalysis include low count rates, specimen instability and mass loss, extraneous contributions to the spectrum, and preparative artifacts affecting quantitation. A relatively recent development in X-ray microanalysis of biological specimens is the quantitative determination of local water content

Experimental study of bolted connections using light gauge channel sections and packing plates at the joints

Science.gov (United States)

Kulkarni, Ravindra B.; Vaghe, Vishal M.

2014-12-01

Cold-formed structural members are being used more widely in routine structural design as the world steel industry moves from the production of hot-rolled section and plate to coil and strip, often with galvanized and/or painted coatings. Steel in this form is more easily delivered from the steel mill to the manufacturing plant where it is usually cold-rolled into open and closed section members. In the present experimental study, the use of packing plate at the joints in cold-formed channel sections may increase the load carrying capacity and also reduce the buckling of unconnected cold form channel steel plate at joints. The present study focuses on examining the experimental investigation to use mild steel as a packing plate with cold-formed channel sections by bolted connection at the joints and the connection subjected to axial tension. Series of tests are carried out with increase in the thickness of packing plate and results are observed and analyzed. Total Twelve experimental tests have been carried out on cold-formed channel tension members fastened with single as well as three numbers of bolts at the connection and from the observations the strength of the joint is increased by increasing the various thicknesses of packing plates and also the buckling of unconnected leg of channel specimen is reduced. It is analyzed by plotting the entire load versus elongation path, so that the behavior of the connection is examined.

Thermal shock fracture of graphite armor plate under the heat load of plasma disruption

International Nuclear Information System (INIS)

Horie, Tomoyoshi; Seki, Masahiro; Ohmori, Junji

1989-01-01

Experiments on the thermal shock brittle fracture of graphite plates were performed. Thermal loading which simulated a plasma disruption was produced by an electron beam facility. Pre-cracks produced on the surface propagated to the inside of the specimen even if the thermal stress on the surface was compressive. Two mechanisms are possible to produce tensile stress around the crack tip under thermal shock conditions. Temperature, thermal stress, and the stress intensity factor for the specimen were analyzed based on the finite element method for various heating conditions. The trend of experimental results under the asymmetric heating agrees qualitatively with the analytical results. This phenomenon is important for the design of plasma facing components made of graphite. Establishment of a lifetime prediction procedure including fatigue, fatigue crack growth, and brittle fracture is needed for graphite armors. (orig.)

Delayed hydride cracking behavior for zircaloy-2 plate

International Nuclear Information System (INIS)

Mills, J.W.; Huang, F.H.

1991-01-01

The delayed hydride cracking (DHC) behaviour for Zircaloy-2 plate was characterized at temperatures ranging from 300 to 550 o F. Specimens with a longitudinal (T-L) orientation exhibited a classic two-stage DHC response. At K values slightly above the threshold level (K th ), crack-growth rates increased dramatically with increasing K values (stage I). The K th value was found to be 11 and 14 ksi√ in at 400 and 500 o F. At high K values (stage II), cracking rates were relatively insensitive to applied K levels. Stage II crack growth was a thermally activated process described by an Arrhenius-type relationship with an activation energy of 65 kJ/mol. This energy level agreed with the theoretical activation energy for hydrogen diffusion into the triaxial stress field ahead of a crack. Above a critical temperature (300 o F), an overtemperature cycle was required to initiate DHC. The magnitude of the thermal excursion required to initiate cracking was found to increase at higher test temperatures. Specimens with a transverse(L-T) orientation showed a very low sensitivity to DHC because of an unfavorable crystallographic orientation for hydride reorientation. Metallographic and fractographic examinations were performed to understand the DHC mechanism. (author)

Locking screw-plate interface stability in carbon-fibre reinforced polyetheretherketone proximal humerus plates.

Science.gov (United States)

Hak, David J; Fader, Ryan; Baldini, Todd; Chadayammuri, Vivek B S

2017-09-01

Carbon-fibre reinforced polyetheretherketone (CFR-PEEK) plates have recently been introduced for proximal humerus fracture treatment. The purpose of this study was to compare the locking screw-plate interface stability in CFR-PEEK versus stainless steel (SS) proximal humerus plates. Locking screw mechanical stability was evaluated independently in proximal and shaft plate holes. Stiffness and load to failure were tested for three conditions: (1) on-axis locking screw insertion in CFR-PEEK versus SS plates, (2) on-axis locking screw insertion, removal, and reinsertion in CFR-PEEK plates, and (3) 10-degree off-axis locking screw insertion in CFR-PEEK plates. Cantilever bending at a rate of 1 mm/minute was produced by an Instron machine and load-displacement data recorded. Shaft locking screw load to failure was significantly greater in CFR-PEEK plates compared to SS plates (746.4 ± 89.7 N versus 596.5 ± 32.6 N, p PEEK plates (p PEEK plates. The mechanical stability of locking screws in CFR-PEEK plates is comparable or superior to locking screws in SS plates.

Deconvolution using thin-plate splines

International Nuclear Information System (INIS)

Toussaint, Udo v.; Gori, Silvio

2007-01-01

The ubiquitous problem of estimating 2-dimensional profile information from a set of line integrated measurements is tackled with Bayesian probability theory by exploiting prior information about local smoothness. For this purpose thin-plate-splines (the 2-D minimal curvature analogue of cubic-splines in 1-D) are employed. The optimal number of support points required for inversion of 2-D tomographic problems is determined using model comparison. Properties of this approach are discussed and the question of suitable priors is addressed. Finally, we illustrated the properties of this approach with 2-D inversion results using data from line-integrated measurements from fusion experiments

Voltage-current characteristics of a pin-plate system with different plate configurations

International Nuclear Information System (INIS)

Feng, Zhuangbo; Long, Zhengwei

2013-01-01

In this paper, the voltage-current (V-I) characteristics of a pin-plate system with four types of collection plate configurations are studied experimentally. The collection plates consider a single metal plate, a metal plate with a fly ash cake layer, a metal plate with a clean filter media and a metal plate with a dirty filter media. The results show that the clean filter media has no obvious effect on the V-I characteristics. But the dirty filter media reduces the current density because of its high resistance. The thick fly ash cake layer increase current density because of the anti-corona effect but the increment is not very obvious.

Transmission loss of plates with embedded acoustic black holes.

Science.gov (United States)

Feurtado, Philip A; Conlon, Stephen C

2017-09-01

In recent years acoustic black holes (ABHs) have been developed and demonstrated as an effective method for developing lightweight, high loss structures for noise and vibration control. ABHs employ a local thickness change to tailor the speed and amplitude of flexural bending waves and create concentrated regions of high strain energy which can be effectively dissipated through conventional damping treatments. These regions act as energy sinks which allow for effective broadband vibration absorption with minimal use of applied damping material. This, combined with the reduced mass from the thickness tailoring, results in a treated structure with higher loss and less mass than the original. In this work, the transmission loss (TL) of plates with embedded ABHs was investigated using experimental and numerical methods in order to assess the usefulness of ABH systems for TL applications. The results demonstrated that damped ABH plates offer improved performance compared to a uniform plate despite having less mass. The result will be useful for applying ABHs and ABH systems to practical noise and vibration control problems.

A screening method for β-glucan hydrolase employing Trypan Blue-coupled β-glucan agar plate and β-glucan zymography.

Science.gov (United States)

Park, Chang-Su; Yang, Hee-Jong; Kim, Dong-Ho; Kang, Dae-Ook; Kim, Min-Soo; Choi, Nack-Shick

2012-06-01

A new screening method for β-(1,3-1,6) glucan hydrolase was developed using a pure β-glucan from Aureobaisidum pullulans by zymography and an LB-agar plate. Paenibacillus sp. was screened as a producer a β-glucan hydrolase on the Trypan Blue-coupled β-glucan LB-agar plate and the activity of the enzyme was analyzed by SDS-β-glucan zymography. The β-glucan was not hydrolyzed by Bacillus spp. strains, which exhibit cellulolytic activity on CMC zymography. The gene, obtaining by shotgun cloning and encoding the β-glucan hydrolase of Paenibacillus sp. was sequenced.

Kinetic description of flow past a micro-plate

International Nuclear Information System (INIS)

Christlieb, Andrew J.; Hitchon, W. Nicholas G.; Boyd, Iain D.; Sun Quanhua

2004-01-01

In this work we discuss a novel numerical scheme and present numerical results for the problem of 'high' (of order unity) Knudsen number, Kn=λ/L, low velocity gas flow past a micro-plate. The scheme used here is similar to one employed in the past to examine heat flow, but in order to deal with momentum transport in the vicinity of a plate, new techniques had to be developed. These include a new scheme for finding 'transition probabilities', which eliminates some forms of numerical diffusion, and a method for handling reflections off surfaces which preserves the essential properties of the flow. The purpose of the paper is to present these methods and examine their performance. The method is found to function well, but the results indicate that the collision operator which is employed here must be improved in order to obtain accurate results for the drag. Low speed neutral particle transport, in long mean free path (LMFP) environments, presents challenges for well-established techniques, such as the direct simulation Monte Carlo (DSMC) method. In particular, at low flow velocities, statistical methods suffer from noise that may render them impractical in LMFP environments. Solution of the Boltzmann equation is the alternative to these statistical methods. As computing power increases, Boltzmann-based approaches become more accessible. We discuss here a novel non-statistical (no random numbers are used) kinetic model for particle transport and explore its accuracy and sensitivity to resolution and other details of its implementation. The model is an enhanced version of the transition probability matrix (TPM) method. The results generated by the TPM are compared with the information preservation (IP) method, the Navier-Stokes (NS) slip model and when applicable to DSMC. We provide a qualitative comparison of the models and then we compare the results of the different models for various Kn for flow past a plate. For Kn in the slip flow regime, the TPM, IP and NS

Reduced and selective integration techniques in the finite element analysis of plates

International Nuclear Information System (INIS)

Hughes, T.J.R.; Cohen, M.; Haroun, M.

1978-01-01

Efforts to develop effective plate bending finite elements by reduced integration techniques are described. The basis for the development is a 'thick' plate theory in which transverse shear strains are accounted for. The variables in the theory are all kinematic, namely, displacements and independent rotations. As only C 0 continuity is required, isoparametric elements may be employed, which result in several advantages over thin plate elements. It is shown that the avoidance of shear 'locking' may be facilitated by reduced integration techniques. Both uniform and selective schemes are considered. Conditions under which selective schemes are invariant are identified, and they are found to have an advantage over uniform schemes in the present situation. It is pointed out that the present elements are not subject to the difficulties encountered by thin plate theory elements, concerning boundary conditions. For example, the polygonal approximation of curved, simply supported edges is convergent. Other topics discussed are the equivalence with mixed methods, rank deficiency, convergence criteria and useful mass 'lumping' schemes for dynamics. Numerical results for several thin plate problems indicate the high degree of accuracy attainable by the present elements. (Auth.)

Controlled Environment Specimen Transfer

DEFF Research Database (Denmark)

Damsgaard, Christian Danvad; Zandbergen, Henny W.; Hansen, Thomas Willum

2014-01-01

an environmental transmission electron microscope to an in situ X-ray diffractometer through a dedicated transmission electron microscope specimen transfer holder, capable of sealing the specimen in a gaseous environment at elevated temperatures. Two catalyst material systems have been investigated; Cu/ZnO/Al2O3...... transferred in a reactive environment to the environmental transmission electron microscope where further analysis on the local scale were conducted. The Co/Al2O3 catalyst was reduced in the environmental microscope and successfully kept reduced outside the microscope in a reactive environment. The in situ......Specimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking...

Thin-plate spline analysis of mandibular growth.

Science.gov (United States)

Franchi, L; Baccetti, T; McNamara, J A

2001-04-01

The analysis of mandibular growth changes around the pubertal spurt in humans has several important implications for the diagnosis and orthopedic correction of skeletal disharmonies. The purpose of this study was to evaluate mandibular shape and size growth changes around the pubertal spurt in a longitudinal sample of subjects with normal occlusion by means of an appropriate morphometric technique (thin-plate spline analysis). Ten mandibular landmarks were identified on lateral cephalograms of 29 subjects at 6 different developmental phases. The 6 phases corresponded to 6 different maturational stages in cervical vertebrae during accelerative and decelerative phases of the pubertal growth curve of the mandible. Differences in shape between average mandibular configurations at the 6 developmental stages were visualized by means of thin-plate spline analysis and subjected to permutation test. Centroid size was used as the measure of the geometric size of each mandibular specimen. Differences in size at the 6 developmental phases were tested statistically. The results of graphical analysis indicated a statistically significant change in mandibular shape only for the growth interval from stage 3 to stage 4 in cervical vertebral maturation. Significant increases in centroid size were found at all developmental phases, with evidence of a prepubertal minimum and of a pubertal maximum. The existence of a pubertal peak in human mandibular growth, therefore, is confirmed by thin-plate spline analysis. Significant morphological changes in the mandible during the growth interval from stage 3 to stage 4 in cervical vertebral maturation may be described as an upward-forward direction of condylar growth determining an overall "shrinkage" of the mandibular configuration along the measurement of total mandibular length. This biological mechanism is particularly efficient in compensating for major increments in mandibular size at the adolescent spurt.

In vitro evaluation of stiffness and load sharing in a two-level corpectomy: comparison of static and dynamic cervical plates.

Science.gov (United States)

Fogel, Guy R; Li, Zhenyu; Liu, Weiqiang; Liao, Zhenhua; Wu, Jia; Zhou, Wenyu

2010-05-01

Anterior cervical plating has been accepted in corpectomy and fusion of the cervical spine. Constrained plates were criticized for stress shielding that may lead to subsidence and pseudarthrosis. A dynamic plate allows load sharing as the graft subsides. Ideally, the dynamic plate design should maintain adequate stiffness of the construct while providing a reasonable load sharing with the strut graft. The purpose of the study was to compare dynamic and static plate kinematics with graft subsidence. The study designed was an in vitro biomechanical study in a porcine cervical spine model. Twelve spines were initially tested in intact condition with 20-N axial load in 15 degrees of flexion and extension range of motion (ROM). Then, a two-level corpectomy was created in all specimens with spines randomized to receive either a static or dynamic plate. The spines were retested under identical conditions with optimal length and undersized graft. Range of motion and graft loading were analyzed with a one-way analysis of variance (p<.05). Both plates significantly limited ROM compared with the intact spine in both graft length conditions. In extension graft, load was significantly higher (p=.001) in the static plate with optimal length, and in flexion, there was a significant loss of graft load (p=.0004). In flexion, the dynamic plate with undersized graft demonstrated significantly more load sustained (p=.0004). Both plates reasonably limited the ROM of the corpectomy. The static plate had significantly higher graft loads in extension and significant loss of graft load in flexion, whereas the dynamic plate maintained a reasonable graft load in ROM even when graft contact was imperfect. Copyright 2010 Elsevier Inc. All rights reserved.

Evaluation of Variation in Residual Strength of Carbon Fiber Reinforced Plastic Plate with a Hole Subjected to Fatigue Load

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Young; Kang, Min Sung; Koo, Jae Mean; Seok, Chang Sung [Sungkyunkwan University, Seoul (Korea, Republic of)

2010-10-15

CFRP (Carbon Fiber Reinforced Plastic) has received considerable attention in various fields as a structural material, because of its high specific strength, high specific stiffness, excellent design flexibility, favorable chemical properties, etc. Most products consisting of several parts are generally assembled by mechanical joining methods (using rivets, bolts, pins, etc.). Holes must be drilled in the parts to be joined, and the strength of the components subjected to static and fatigue loads caused by stress concentration must be decreased. In this study, we experimentally evaluated the variation in the residual strength of a holenotched CFRP plate subjected to fatigue load. We repeatedly subjected the hole-notched specimen to fatigue load for a certain number of cycles, and then we investigated the residual strength of the hole-notched specimen by performing the fracture test. From the results of the test, we can observe the initiation of a directional crack caused by the applied fatigue load. Further, we observed that the residual strength increases with a decrease in the notch effect due to this crack. It was evaluated that the residual strength increases to a certain level and subsequently decreases. This variation in the residual strength was represented by a simple equation by using a model of the decrease in residual strength for plain plate, which was developed by Reifsnider and a stress redistribution model for hole-notched plate, which was developed by Yip.

Nonlinear vibrations of thin arbitrarily laminated composite plates subjected to harmonic excitations using DKT elements

Science.gov (United States)

Chiang, C. K.; Xue, David Y.; Mei, Chuh

1993-04-01

A finite element formulation is presented for determining the large-amplitude free and steady-state forced vibration response of arbitrarily laminated anisotropic composite thin plates using the Discrete Kirchhoff Theory (DKT) triangular elements. The nonlinear stiffness and harmonic force matrices of an arbitrarily laminated composite triangular plate element are developed for nonlinear free and forced vibration analyses. The linearized updated-mode method with nonlinear time function approximation is employed for the solution of the system nonlinear eigenvalue equations. The amplitude-frequency relations for convergence with gridwork refinement, triangular plates, different boundary conditions, lamination angles, number of plies, and uniform versus concentrated loads are presented.

Effect of processing conditions on residual stress distributions by bead-on-plate welding after surface machining

International Nuclear Information System (INIS)

Ihara, Ryohei; Mochizuki, Masahito

2014-01-01

Residual stress is important factor for stress corrosion cracking (SCC) that has been observed near the welded zone in nuclear power plants. Especially, surface residual stress is significant for SCC initiation. In the joining processes of pipes, butt welding is conducted after surface machining. Residual stress is generated by both processes, and residual stress distribution due to surface machining is varied by the subsequent butt welding. In previous paper, authors reported that residual stress distribution generated by bead on plate welding after surface machining has a local maximum residual stress near the weld metal. The local maximum residual stress shows approximately 900 MPa that exceeds the stress threshold for SCC initiation. Therefore, for the safety improvement of nuclear power plants, a study on the local maximum residual stress is important. In this study, the effect of surface machining and welding conditions on residual stress distribution generated by welding after surface machining was investigated. Surface machining using lathe machine and bead on plate welding with tungsten inert gas (TIG) arc under various conditions were conducted for plate specimens made of SUS316L. Then, residual stress distributions were measured by X-ray diffraction method (XRD). As a result, residual stress distributions have the local maximum residual stress near the weld metal in all specimens. The values of the local maximum residual stresses are almost the same. The location of the local maximum residual stress is varied by welding condition. It could be consider that the local maximum residual stress is generated by same generation mechanism as welding residual stress in surface machined layer that has high yield stress. (author)

Theoretical investigation of interaction between a rectangular plate and fractional viscoelastic foundation

Directory of Open Access Journals (Sweden)

Chengcheng Zhang

2014-08-01

Full Text Available The interaction between plates and foundations is a typical problem encountered in geotechnical engineering. The long-term plate performance is highly dependent on the rheological characteristics of ground soil. Compared with conventional linear rheology, the fractional calculus-based theory is a more powerful mathematical tool that can address this issue. This paper proposes a fractional Merchant model (FMM to investigate the time-dependent behavior of a simply supported rectangular plate on viscoelastic foundation. The correspondence principle involving Laplace transforms was employed to derive the closed-form solutions of plate response under uniformly distributed load. The plate deflection, bending moment, and foundation reaction calculated using the FMM were compared with the results obtained from the analogous elastic model (EM and the standard Merchant model (SMM. It is shown that the upper and lower bound solutions of the FMM can be determined using the EM. In addition, a parametric study was performed to examine the influences of the model parameters on the time-dependent behavior of the plate–foundation interaction problem. The results indicate that a small fractional differential order corresponds to a plate resting on a sandy soil foundation, while the fractional differential order value should be increased for a clayey soil foundation. The long-term performance of a foundation plate can be accurately simulated by varying the values of the fractional differential order and the viscosity coefficient. The observations from this study reveal that the proposed fractional model has the capability to capture the variation of plate deflection over many decades of time.

Irradiation testing of stainless steel plate material and weldments. Report on ITER Task T14, Part B. Tensile properties after 0.5 and 5 dpa at 350 and 500 K

International Nuclear Information System (INIS)

Rensman, J.W.; Boskeljon, J.; Horsten, M.G.; De Vries, M.I.

1997-10-01

The tensile properties of unirradiated and neutron irradiated type 316L(N)-SPH stainless steel plate, EB weldments, 16-8 TIG-weldments, and full 16-8 TIG-deposits have been measured. Miniature 4 mm diameter test specimens of the European Reference Heat 1 and 2 (ERH), and 4 mm and some 8 mm diameter specimens of the weldments mentioned above, were irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands, simulating the first wall conditions by a combination of high displacement damage with high amounts of helium. The irradiation conditions were 0.5 and 5 displacements per atom (dpa) at 350K and 0.5 and 5 dpa at 500K. Testing temperatures ranged from 300K to 850K. This work was performed as part of the European Fusion Technology Programme for ITER as 'Irradiation testing of stainless steel' The report contains the experimental conditions and summarises the results. The tensile properties of the unirradiated ERH's 1 and 2 plate materials were found to differ slightly but significantly: ERH2 has a lower UTS, but higher yield strength and ductility than ERH1. The plate materials have lower yield strength in the unirradiated condition than all of the weldments (EB, TIG-weld and TIG-deposit), accompanied by a higher ductility of the plate materials. When irradiated at 350K the differences in strength between the plate and weld materials decrease, but the ductility of the plate remains higher than that of the weldments. A saturation of irradiation damage has taken place already at about 0.5 dpa. When irradiated at 500K the plate material continuously hardens up to 5 dpa, where it has lost all uniform plastic ductility. The weldments show similar but less dramatic hardening and loss of ductility as the plate material for both irradiation conditions. 54 figs., 17 tabs., 21 refs

Development of fatigue life evaluation method using small specimen

International Nuclear Information System (INIS)

Nogami, Shuhei; Nishimura, Arata; Wakai, Eichi; Tanigawa, Hiroyasu; Itoh, Takamoto; Hasegawa, Akira

2013-01-01

For developing the fatigue life evaluation method using small specimen, the effect of specimen size and shape on the fatigue life of the reduced activation ferritic/martensitic steels (F82H-IEA, F82H-BA07 and JLF-1) was investigated by the fatigue test at room temperature in air using round-bar and hourglass specimens with various specimen sizes (test section diameter: 0.85–10 mm). The round-bar specimen showed no specimen size and no specimen shape effects on the fatigue life, whereas the hourglass specimen showed no specimen size effect and obvious specimen shape effect on it. The shorter fatigue life of the hourglass specimen observed under low strain ranges could be attributed to the shorter micro-crack initiation life induced by the stress concentration dependent on the specimen shape. On the basis of this study, the small round-bar specimen was an acceptable candidate for evaluating the fatigue life using small specimen

Anatomical Thin Titanium Mesh Plate Structural Optimization for Zygomatic-Maxillary Complex Fracture under Fatigue Testing

Directory of Open Access Journals (Sweden)

Yu-Tzu Wang

2018-01-01

Full Text Available This study performs a structural optimization of anatomical thin titanium mesh (ATTM plate and optimal designed ATTM plate fabricated using additive manufacturing (AM to verify its stabilization under fatigue testing. Finite element (FE analysis was used to simulate the structural bending resistance of a regular ATTM plate. The Taguchi method was employed to identify the significance of each design factor in controlling the deflection and determine an optimal combination of designed factors. The optimal designed ATTM plate with patient-matched facial contour was fabricated using AM and applied to a ZMC comminuted fracture to evaluate the resting maxillary micromotion/strain under fatigue testing. The Taguchi analysis found that the ATTM plate required a designed internal hole distance to be 0.9 mm, internal hole diameter to be 1 mm, plate thickness to be 0.8 mm, and plate height to be 10 mm. The designed plate thickness factor primarily dominated the bending resistance up to 78% importance. The averaged micromotion (displacement and strain of the maxillary bone showed that ZMC fracture fixation using the miniplate was significantly higher than those using the AM optimal designed ATTM plate. This study concluded that the optimal designed ATTM plate with enough strength to resist the bending effect can be obtained by combining FE and Taguchi analyses. The optimal designed ATTM plate with patient-matched facial contour fabricated using AM provides superior stabilization for ZMC comminuted fractured bone segments.

Oblique Wave-Induced Responses of A VLFS Edged with A Pair of Inclined Perforated Plates

Science.gov (United States)

Cheng, Yong; Ji, Chun-yan; Zhai, Gang-jun; Oleg, Gaidai

2018-03-01

This paper is concerned with the hydroelastic responses of a mat-like, rectangular very large floating structure (VLFS) edged with a pair of horizontal/inclined perforated anti-motion plates in the context of the direct coupling method. The updated Lagrangian formulae are applied to establish the equilibrium equations of the VLFS and the total potential formula is employed for fluids in the numerical model including the viscous effect of the perforated plates through the Darcy's law. The hybrid finite element-boundary element (FE-BE) method is implemented to determine the response reduction of VLFS with attached perforated plates under various oblique incident waves. Also, the numerical solutions are validated against a series of experimental tests. The effectiveness of the attached perforated plates in reducing the deflections of the VLFS can be significantly improved by selecting the proper design parameters such as the porous parameter, submergence depth, plate width and inclination angle for the given sea conditions.

Welding procedure specification for arc welding of St 52-3N steel plates with covered electrodes

International Nuclear Information System (INIS)

Cvetkovski, S.; Slavkov, D.; Magdeski, J.

2003-01-01

In this paper the results of approval welding technology for arc welding of plates made of St 52-3N steel are presented. Metal arc welding with covered electrode is used welding process. Test specimens are butt welded in different welding positions P A , P F , P C and P D . Before start welding preliminary welding procedure was prepared. After welding of test specimens non destructive and destructive testing was performed. Obtained results were compared with standard DIN 17100 which concerns to chemical composition and mechanical properties of base material. It was confirmed that in all cases mechanical properties of welded joint are higher than those of base material, so preliminary welding procedure (pWTS) can be accepted as welding procedure specification WPS for metal arc welding of St52-3N steel. (Original)

A Visualization Method for Corrosion Damage on Aluminum Plates Using an Nd:YAG Pulsed Laser Scanning System.

Science.gov (United States)

Lee, Inbok; Zhang, Aoqi; Lee, Changgil; Park, Seunghee

2016-12-16

This paper proposes a non-contact nondestructive evaluation (NDE) technique that uses laser-induced ultrasonic waves to visualize corrosion damage in aluminum alloy plate structures. The non-contact, pulsed-laser ultrasonic measurement system generates ultrasonic waves using a galvanometer-based Q-switched Nd:YAG laser and measures the ultrasonic waves using a piezoelectric (PZT) sensor. During scanning, a wavefield can be acquired by changing the excitation location of the laser point and measuring waves using the PZT sensor. The corrosion damage can be detected in the wavefield snapshots using the scattering characteristics of the waves that encounter corrosion. The structural damage is visualized by calculating the logarithmic values of the root mean square (RMS), with a weighting parameter to compensate for the attenuation caused by geometrical spreading and dispersion of the waves. An intact specimen is used to conduct a comparison with corrosion at different depths and sizes in other specimens. Both sides of the plate are scanned with the same scanning area to observe the effect of the location where corrosion has formed. The results show that the damage can be successfully visualized for almost all cases using the RMS-based functions, whether it formed on the front or back side. Also, the system is confirmed to have distinguished corroded areas at different depths.

Region-selective electroless gold plating on polycarbonate sheets by UV-patterning in combination with silver activating

Energy Technology Data Exchange (ETDEWEB)

Zhou Qinghua [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Zijin' gang Campus, Hangzhou 310058 (China); Chen Hengwu, E-mail: hwchen@zju.edu.c [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Zijin' gang Campus, Hangzhou 310058 (China); Wang Yi [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Zijin' gang Campus, Hangzhou 310058 (China)

2010-02-28

A simple, time- and cost-effective approach for region-selective metalization of polycarbonate (PC) surface has been established by combining photoresist-free UV-patterning with tin- and amine-free silver activating and electroless gold plating. The surface of PC sheets was exposed to the UV lights emitted from a low-pressure mercury lamp through a photomask, the micro pattern on the mask being transferred to the PC surface due to the photochemical generation of carboxyl groups on the UV-exposed region. The UV-exposed PC sheets were then treated with an ammoniacal AgNO{sub 3} solution, so that the silver ions were chemisorbed by the photochemically generated carboxyl groups. When the Ag{sup +}-adsorbed PC sheet was immersed into an electroless gold plating bath, shiny gold film quickly deposited on the UV-exposed region, resulting in the formation of a micro gold devices on the PC surface. The whole plating process including UV-exposure, surface activating and gold plating can be completed in about 3-4 h. Attenuated total reflection Fourier transformation infrared spectrometer (ATR-FT-IR), X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and scanning electron microscope (SEM) were employed to trace the surface change during the plating process. Cyclic voltammetry (CV) and Scotch-tape test were employed to characterize the electrochemical properties and adhesion strength of the prepared micro gold devices, respectively. The prepared micro gold electrodes were demonstrated for amperometric detection of hydrogen peroxide.

Simplified Paper Format for Detecting HIV Drug Resistance in Clinical Specimens by Oligonucleotide Ligation

Science.gov (United States)

Panpradist, Nuttada; Beck, Ingrid A.; Chung, Michael H.; Kiarie, James N.; Frenkel, Lisa M.; Lutz, Barry R.

2016-01-01

Human immunodeficiency virus (HIV) is a chronic infection that can be managed by antiretroviral treatment (ART). However, periods of suboptimal viral suppression during lifelong ART can select for HIV drug resistant (DR) variants. Transmission of drug resistant virus can lessen or abrogate ART efficacy. Therefore, testing of individuals for drug resistance prior to initiation of treatment is recommended to ensure effective ART. Sensitive and inexpensive HIV genotyping methods are needed in low-resource settings where most HIV infections occur. The oligonucleotide ligation assay (OLA) is a sensitive point mutation assay for detection of drug resistance mutations in HIV pol. The current OLA involves four main steps from sample to analysis: (1) lysis and/or nucleic acid extraction, (2) amplification of HIV RNA or DNA, (3) ligation of oligonucleotide probes designed to detect single nucleotide mutations that confer HIV drug resistance, and (4) analysis via oligonucleotide surface capture, denaturation, and detection (CDD). The relative complexity of these steps has limited its adoption in resource-limited laboratories. Here we describe a simplification of the 2.5-hour plate-format CDD to a 45-minute paper-format CDD that eliminates the need for a plate reader. Analysis of mutations at four HIV-1 DR codons (K103N, Y181C, M184V, and G190A) in 26 blood specimens showed a strong correlation of the ratios of mutant signal to total signal between the paper CDD and the plate CDD. The assay described makes the OLA easier to perform in low resource laboratories. PMID:26751207

Specimen holder for an electron microscope and device and method for mounting a specimen in an electron microscope

NARCIS (Netherlands)

Zandbergen, H.W.; Latenstein van Voorst, A.; Westra, C.; Hoveling, G.H.

1996-01-01

A specimen holder for an electron microscope, comprising a bar-shaped body provided adjacent one end with means for receiving a specimen, with means being present for screening the specimen from the environment at least temporarily in airtight and moisture-proof manner in a first position, which

A general mixed mode fracture mechanics test specimen: The DCB-specimen loaded with uneven bending moments

Energy Technology Data Exchange (ETDEWEB)

Soerensen, B.F.; Joergensen, K.; Oestergaard, R.C. [Risoe National Lab., Materials Dept., Roskilde (Denmark); Jacobsen, T.K. [LM Glasfiber A/S, Lunderskov (Denmark)

2004-03-01

A mixed mode specimen is proposed for fracture mechanics characterisation of adhesive joints, laminates and multilayers. The specimen is a double cantilever beam specimen loaded with uneven bending moments at the two free beams. By varying the ratio between the two applied moments, the full mode mixity range from pure mode I to pure mode II can be generated for the same specimen geometry. The specimen allows stable crack growth. In case of large scale crack bridging, mixed mode cohesive laws can be obtained by a J integral based approach. As a preliminary example, fracture of adhesive joints between two glass-fibre laminates was studied. The mixed mode fracture resistance increased with increasing crack length due to fibre cross over bridging, eventually reaching a steady-state level (R-curve behaviour). The steady-state fracture toughness level increased with increasing tangential crack opening displacement. Cohesive stresses were determined by a J integral approach. The deducted shear stress was found to be relative high ({approx} = 20 MPa) in comparison with the normal stress ({approx} = 1 MPa). (au)

Preparation of TiN films by arc ion plating using dc and pulsed biases

International Nuclear Information System (INIS)

Huang, M.D.; Lee, Y.P.; Dong, C.; Lin, G.Q.; Sun, C.; Wen, L.S.

2004-01-01

TiN hard coatings were prepared by arc ion plating with both direct current (dc) and pulsed biases. An extensive investigation was undertaken to determine the effects of the substrate temperature on the mechanical properties and the microstructures of films. The results show that the substrate temperature is decreased evidently when a pulsed bias instead of a dc one is employed. At the same time, the microstructures and the properties are also improved. A low-temperature arc ion plating can be realized by using pulsed biases

A Possible Differentially Shortened Strike-slip Plate Boundary: the Okhotsk Plate Example.

Science.gov (United States)

Hindle, D.; Egorov, V.; Mackey, K. G.; Fujita, K.

2004-12-01

The Okhotsk plate has been postulated based on a combination of GPS geodetic inversions (REVEL1), seimsicity, geologic and lineament data. Lying between the North American and Eurasian plates, its northwestern corner would appear to be undergoing compression in a scissors motion between the two bounding plates. Extrusion tectonics along multiple, large strike-slip faults within the Okhotsk plate itself have been suggested to allow the escape of material away from the apex of Eurasia-North America. The plate boundary between Okhotsk and North America has been suggested to be diffuse, based on widely scattered minor seismicity. However, the large, left lateral, Ulakhan fault has also been suggested as a candidate plate boundary. We present field geological and geomorphological evidence of the partitioning of deformation between the Ulakhan fault, and several parallel and oblique, linked faults. The Ulakhan fault strand appears to have a maximum displacement of 24 km based on river valley offsets and closing large pull apart basins. Some of the displacement from the Ulakhan fault appears relayed into the plate margin along oblique trending, thrust/oblique slip faults. Estimated shortening over these faults is equivalent to the amount of shortening relayed into the plate margin from the plate boundary. There may be several thrust/oblique slip faults along the Ulakhan fault, which leads to the interesting situation of a segmented, strike-slip plate boundary being actively shortened in a margin parallel direction. This may be the result of postulated extrusion of the Okhotsk plate due to North America/Eurasia convergence. Such a situation would have important consequences for the interpretation of GPS data in a plate tectonic context.

An autoradiographical method using an imaging plate for the analyses of plutonium contamination in a plutonium handling facility

International Nuclear Information System (INIS)

Takasaki, Koji; Sagawa, Naoki; Kurosawa, Shigeyuki; Mizuniwa, Harumi

2011-01-01

An autoradiographical method using an imaging plate (IP) was developed to analyze plutonium contamination in a plutonium handling facility. The IPs were exposed to ten specimens having a single plutonium particle. Photostimulated luminescence (PSL) images of the specimens were taken using a laser scanning machine. One relatively large spot induced by α-radioactivity from plutonium was observed in each PSL image. The plutonium-induced spots were discriminated by a threshold derived from background and the size of the spot. A good relationship between the PSL intensities of the spots and α-radioactivities measured using a radiation counter was obtained by least-square fitting, taking the fading effect into consideration. This method was applied to workplace monitoring in an actual uranium-plutonium mixed oxide (MOX) fuel fabrication facility. Plutonium contaminations were analyzed in ten other specimens having more than two plutonium spots. The α-radioactivities of plutonium contamination were derived from the PSL images and their relative errors were evaluated from exposure time. (author)

An Experimental Evaluation of Electron Beam Welded Thixoformed 7075 Aluminum Alloy Plate Material

Directory of Open Access Journals (Sweden)

Ava Azadi Chegeni

2017-12-01

Full Text Available Two plates of thixoformed 7075 aluminum alloy were joined using Electron Beam Welding (EBW. A post-welding-heat treatment (PWHT was performed within the semi-solid temperature range of this alloy at three temperatures, 610, 617 and 628 °C, for 3 min. The microstructural evolution and mechanical properties of EB welded plates, as well as the heat-treated specimens, were investigated in the Base Metal (BM, Heat Affected Zone (HAZ, and Fusion Zone (FZ, using optical microscopy, Scanning Electron Microscopy (SEM, EDX (Energy Dispersive X-ray Analysis, and Vickers hardness test. Results indicated that after EBW, the grain size substantially decreased from 67 µm in both BM and HAZ to 7 µm in the FZ, and a hardness increment was observed in the FZ as compared to the BM and HAZ. Furthermore, the PWHT led to grain coarsening throughout the material, along with a further increase in hardness in the FZ.

Inspection of SiC{sub f}/SiC ceramic matrix composite specimens employed for fatigue experiments via laboratory X-ray computed microtomography

Energy Technology Data Exchange (ETDEWEB)

Quiney, Z.; Bache, M.R.; Jones, J.P. [Swansea Univ. (United Kingdom). Inst. of Structural Materials

2015-07-01

Hi-Nicalon SiC{sub f}/SiC ceramic matrix composite (CMC) specimens have been inspected using laboratory based X-ray computed micro-tomography (μCT) both prior and subsequent to isothermal fatigue assessment. The fatigue specimens were in the form of a dog bone-shaped geometry with a minimum cross-sectional area of 40 mm{sup 2}. Pre-test μCT inspections were conducted to identify the subsurface composite architecture and locate associated features introduced during the manufacturing process (e.g. isolated or conjoined porosity, matrix or interface discontinuities etc.). These μCT scans were subsequently correlated with matching post-test volumes in an attempt to determine the influence of such features upon damage accumulation and the ultimate failure position and cyclic damage mode(s). The relationship between μCT scan resolution and identification of critical features is also discussed. In typical cone-beam X-ray systems, resolution is proportional to the source-to-specimen distance, but for efficiency may also be chosen so as to minimise the number of scans needed to capture the whole area of interest. The investigations are intended to provide input into the future development of an in situ mechanical testing μCT facility using lab-based X-ray systems.

Mechanical System Analysis of C-Frame for Steel Plate Thickness Gauge

International Nuclear Information System (INIS)

Sri Sudadiyo

2007-01-01

Nuclear base instrument is not only applied in the area of research such as medical and agriculture sciences, but also in the field of industry especially for thickness gauge. To the present at the steel industry, the gauge that is applied to cut plate thickness using infra-red ray method, it cannot result in accurately data. To solve that case, it is developed a thickness gauge of steel plate by using gamma ray method that it is named C-Frame. This thickness gauge is hoped that it could control in cutting the steel plate by on-line, accurate, and safe, therefore, it could socialize the advanced technology in the nuclear field to support the production process in domestic industries (national industries). The present study yields the calculations of mechanical system of that C-Frame including structure, detector support, source container of radioisotope, and transmission system, be also computed by running Professional Microsoft Fortran Version 5.10, NISA-II program, and AutoCAD program. From the obtained results could be known that the design meets the requirement, so that could be employed properly to measure the thickness of plate in the steel industries. (author)

On the prediction of condenser plate temperatures in a cross-flow condenser

NARCIS (Netherlands)

Ganzevles, F.L.A.; Geld, van der C.W.M.

2002-01-01

A prediction method is presented for the gas-sided plate temperatures at the inlet and at the outlet of a compact, cross-flow condenser. The method employs measured (or predicted) heat flow rates and temperatures of both coolant and gas, at inlet and outlet. The method is validated using infrared

Multicentre validation of 4-well azole agar plates as a screening method for detection of clinically relevant azole-resistant Aspergillus fumigatus

DEFF Research Database (Denmark)

Arendrup, Maiken Cavling; Verweij, Paul E; Mouton, Johan W

2017-01-01

Objectives: Azole-resistant Aspergillus fumigatus is emerging worldwide. Reference susceptibility testing methods are technically demanding and no validated commercial susceptibility tests for moulds currently exist. In this multicentre study a 4-well azole-containing screening agar method...... following E.Def 9.3. In-house and commercial 4-well plates containing agars supplemented with 4 mg/L itraconazole, 1 mg/L voriconazole, 0.5 mg/L posaconazole and no antifungal, respectively, were evaluated. Growth was scored (0-3) by two independent observers in three laboratories. Inter-plate, inter...... agreement (no growth versus growth) was excellent (median 95%-100%, range 87%-100%, overall). The overall sensitivity and specificity for the 4-well plate (no growth versus growth) was 99% (range 97%-100%) and 99% (95%-100%), respectively. The sensitivity for simulated WT/mutant specimens was 94% (range 83...

Effect of Plate Curvature on Blast Response of Structural Steel Plates

Science.gov (United States)

Veeredhi, Lakshmi Shireen Banu; Ramana Rao, N. V.; Veeredhi, Vasudeva Rao

2018-04-01

In the present work an attempt is made, through simulation studies, to determine the effect of plate curvature on the blast response of a door structure made of ASTM A515 grade 50 steel plates. A door structure with dimensions of 5.142 m × 2.56 m × 10 mm having six different radii of curvatures is analyzed which is subjected to blast load. The radii of curvature investigated are infinity (flat plate), 16.63, 10.81, 8.26, 6.61 and 5.56 m. In the present study, a stand-off distance of 11 m is considered for all the cases. Results showed that the door structure with smallest radius of curvature experienced least plastic deformation and yielding when compared to a door with larger radius of curvature with same projected area. From the present Investigation, it is observed that, as the radius of curvature of the plate increases, the deformation mode gradually shifts from indentation mode to flexural mode. The plates with infinity and 16.63 m radius of curvature have undergone flexural mode of deformation and plates with 6.61 and 5.56 m radius of curvature undergo indentation mode of deformation. Whereas, mixed mode of deformation that consists of both flexural and indentation mode of deformations are seen in the plates with radius of curvature 10.81 and 8.26 m. As the radius of curvature of the plate decreases the ability of the plate to mitigate the effect the blast loads increased. It is observed that the plate with smaller radius of curvature deflects most of the blast energy and results in least indentation mode of deformation. The most significant observation made in the present investigation is that the strain energy absorbed by the steel plate gets reduced to 1/3 rd when the radius of curvature is approximately equal to the stand-off distance which could be the critical radius of curvature.

A general mixed mode fracture mechanics test specimen: The DCB-specimen loaded with uneven bending moments

DEFF Research Database (Denmark)

Sørensen, Bent F.; Jørgensen, K.; Jacobsen, T.K.

2004-01-01

A mixed mode specimen is proposed for fracture mechanics characterisation of adhesive joints, laminates and multilayers. The specimen is a double cantilever beam specimen loaded with uneven bending moments at the two free beams. By varying the ratiobetween the two applied moments, the full mode...... glass-fibre laminates was studied. The mixed mode fracture resistance increased with increasing crack length due to fibre bridging, eventually reaching asteady-state level (R-curve behaviour). The steady-state fracture toughness level increased with increasing tangential crack opening displacement....

The Okhotsk Plate and the Eurasia-North America plate boundary zone.

Science.gov (United States)

Hindle, David; Mackey, Kevin

2014-05-01

The Eurasia-North America plate boundary zone transitions from spreading at rates of ~ 25mm/yr in the North Atlantic, to compression at rates of ~ 5mm/yr in the region of the Okhotsk plate. Because the pole of rotation between Eurasia and North America lies more or less on their mutual boundary, there is a linear change in rate along the boundary, and regions near the euler pole are subject to extremely low deformation rates. The Okhotsk - Eurasia - North America triple junction lies slightly south of the rotation pole, placing the Okhotsk plate entirely in a weakly contractional setting. Regions near the triple junction absorb 1mm/yr contraction. Further south, towards the shoreline of the Okhotsk sea, up to 5 mm/yr contraction may be absorbed within the plate. How shortening is accommodated across the boundary remains an open question. One possibility is wholesale extrusion of the entire Okhotsk plate (or possibly its northwestern corner) along two plate boundary strike slip faults (Eurasia-Okhostk and North America Okhotsk). The problem with this model is that the seismic record does not presently clearly support it, with the largest events distributed both within the plate interior and on its boundaries. This may suggest that instead, the Okhotsk plate, and particularly its north-western end, consists of a series of smaller blocks which shuffle against each other, partially accommodating extrusion, but also permitting some internal deformation and change of shape of the Okhotsk plate itself. We present analyses of the very sparse seismic record from the region, as well as geometric-kinematic, tectonic models of the possible deformation of northwest Okhotsk to try to better understand the different probabilities of how this slowly deforming plate boundary zone is behaving.

Integral transform solution of bending problem of clamped orthotropic rectangular plates

International Nuclear Information System (INIS)

An, C.; Gu, J.-J.; Su, J.

2011-01-01

The generalized integral transform technique (GITT) is employed to obtain an exact solution for the bending problem of fully clamped orthotropic rectangular plates. The use of the GITT approach in the analysis of the transverse deflection equation leads to a coupled system of fourth order differential equations in the dimensionless longitudinal spatial variable. The resulting transformed ODE system is then numerically solved by making use of the subroutine DBVPFD from IMSL Library. Numerical results with automatic global accuracy control are produced for different values of aspect ratio. Critical comparisons with previously reported numerical results are performed with excellent agreement. Several sets of reference results for clamped orthotropic rectangular plates are also provided for future covalidation purposes. (author)

Three dimensional mathematical modeling of violin plate surfaces: An approach based on an ensemble of contour lines.

Science.gov (United States)

Piantadosi, Steven

2017-01-01

This paper presents an approach to describing the three dimensional shape of a violin plate in mathematical form. The shape description begins with standard contour lines and ends with an equation for a surface in three dimensional space. The traditional specification of cross sectional arching is unnecessary. Advantages of this approach are that it employs simple and universal description of plate geometry and yields a complete, smoothed, precise mathematical equation of the plate that is suitable for modern three dimensional production. It is quite general and suitable for both exterior and interior plate surfaces, yielding the ability to control thicknesses along with shape. This method can produce mathematical descriptions with tolerances easily less than 0.001 millimeters suitable for modern computerized numerical control carving and hand finishing.

Recent advances in FIB-TEM specimen preparation techniques

International Nuclear Information System (INIS)

Li Jian; Malis, T.; Dionne, S.

2006-01-01

Preparing high-quality transmission electron microscopy (TEM) specimens is of paramount importance in TEM studies. The development of the focused ion beam (FIB) microscope has greatly enhanced TEM specimen preparation capabilities. In recent years, various FIB-TEM foil preparation techniques have been developed. However, the currently available techniques fail to produce TEM specimens from fragile and ultra-fine specimens such as fine fibers. In this paper, the conventional FIB-TEM specimen preparation techniques are reviewed, and their advantages and shortcomings are compared. In addition, a new technique suitable to prepare TEM samples from ultra-fine specimens is demonstrated

Heat transfer in porous medium embedded with vertical plate: Non-equilibrium approach - Part A

Energy Technology Data Exchange (ETDEWEB)

Badruddin, Irfan Anjum [Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 (Malaysia); Quadir, G. A. [School of Mechatronic Engineering, University Malaysia Perlis, Pauh Putra, 02600 Arau, Perlis (Malaysia)

2016-06-08

Heat transfer in a porous medium embedded with vertical flat plate is investigated by using thermal non-equilibrium model. Darcy model is employed to simulate the flow inside porous medium. It is assumed that the heat transfer takes place by natural convection and radiation. The vertical plate is maintained at isothermal temperature. The governing partial differential equations are converted into non-dimensional form and solved numerically using finite element method. Results are presented in terms of isotherms and streamlines for various parameters such as heat transfer coefficient parameter, thermal conductivity ratio, and radiation parameter.

Heat transfer in porous medium embedded with vertical plate: Non-equilibrium approach - Part A

International Nuclear Information System (INIS)

Badruddin, Irfan Anjum; Quadir, G. A.

2016-01-01

Heat transfer in a porous medium embedded with vertical flat plate is investigated by using thermal non-equilibrium model. Darcy model is employed to simulate the flow inside porous medium. It is assumed that the heat transfer takes place by natural convection and radiation. The vertical plate is maintained at isothermal temperature. The governing partial differential equations are converted into non-dimensional form and solved numerically using finite element method. Results are presented in terms of isotherms and streamlines for various parameters such as heat transfer coefficient parameter, thermal conductivity ratio, and radiation parameter

Reliability of 46,XX results on miscarriage specimens: a review of 1,222 first-trimester miscarriage specimens.

Science.gov (United States)

Lathi, Ruth B; Gustin, Stephanie L F; Keller, Jennifer; Maisenbacher, Melissa K; Sigurjonsson, Styrmir; Tao, Rosina; Demko, Zach

2014-01-01

To examine the rate of maternal contamination in miscarriage specimens. Retrospective review of 1,222 miscarriage specimens submitted for chromosome testing with detection of maternal cell contamination (MCC). Referral centers requesting genetic testing of miscarriage specimens at a single reference laboratory. Women with pregnancy loss who desire complete chromosome analysis of the pregnancy tissue. Analysis of miscarriage specimens using single-nucleotide polymorphism (SNP) microarray technology with bioinformatics program to detect maternal cell contamination. Chromosome content of miscarriages and incidence of 46,XX results due to MCC. Of the 1,222 samples analyzed, 592 had numeric chromosomal abnormalities, and 630 were normal 46,XX or 46,XY (456 and 187, respectively). In 269 of the 46,XX specimens, MCC with no embryonic component was found. With the exclusion of maternal 46,XX results, the chromosomal abnormality rate increased from 48% to 62%, and the ratio for XX to XY results dropped from 2.6 to 1.0. Over half of the normal 46,XX results in miscarriage specimens were due to MCC. The use of SNPs in MCC testing allows for precise identification of chromosomal abnormalities in miscarriage as well as MCC, improving the accuracy of products of conception testing. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Development of fatigue life evaluation technique using miniature specimen

International Nuclear Information System (INIS)

Nogami, Shuhei; Nishimura, Arata; Fujiwara, Masaharu; Hisaka, Tomoaki

2012-01-01

To develop the fatigue life evaluation technique using miniature specimen, the investigation of the effect of specimen size and specimen shape on the fatigue life and the development of the fatigue testing machine, especially the extensometer, were carried out. The effect of specimen size on the fatigue life was almost negligible for the round-bar specimens. The shorter fatigue life at relatively low strain range conditions for the hourglass specimen that the standard specimen were observed. Therefore the miniature round-bar specimen was considered to be adequate for the fatigue life evaluation using small specimen. Several types of the extensometer system using a strain gauge and a laser has been developed for realizing the fatigue test of the miniature round-bar specimen at high temperature in vacuum. (author)

Active gas discharge cleaning for superconducting lead-plated resonators

International Nuclear Information System (INIS)

Malev, M.D.; Weisser, D.C.

1985-06-01

Lead-plating for superconducting RF resonators historically has been directed toward reducing grain size and eliminating spikes on the surface. Investigations were made of degassing lead-plated surfaces under RF resonant electron discharge or multipacting. The mass-spectra of the residual atmosphere showed that decomposition of hydrocarbons on the surface took place. Discolouration of the lead surface, due to the formation of a carbon layer, was easily observed. A method of cleaning surfaces by ion bombardment employing chemically active gases, was proposed and tested. An RF discharge, initiated by multipacting at pressure 10 -2 - 10 -1 torr was used. The first step, discharge treatment in a CO 2 atmosphere, assures oxidation of carbon and hydrocarbons into gaseous compounds which are removed by pumping. During the second step, discharge treatment in a hydrogen atmosphere, lead oxides are reduced to metal

Finite element analysis of a solar collector plate using two plate geometries

Directory of Open Access Journals (Sweden)

Diego Manuel Medina Carril

2016-09-01

Full Text Available The thermal behavior of an absorber plate in a solar collector is investigated using finite element analysis. The thermal behavior and efficiency of two absorber plate geometries are studied, using a typical solar collector with a rectangular profile as reference, and a proposed absorber plate with curved geometry. An analysis of the most important parameters involved in the design of the absorber plate was carried out, indicating that the curved geometry of the absorber plate yields an average efficiency ~25% higher than the conventional rectangular geometry. The results suggest that a curved profile made of materials such as aluminum with thermal conductivity higher than 200W/m°C, plate thickness of the order of 2-3mm and with a large density of tubes per unit area of the collector´s plate greatly benefits the thermal efficiency of the solar collector.

Charpy impact test results on five materials and NIST verification specimens using instrumented 2-mm and 8-mm strikers

International Nuclear Information System (INIS)

Nanstad, R.K.; Sokolov, M.A.

1995-01-01

The Heavy-Section Steel Irradiation Program at Oak Ridge National Laboratory is involved in two cooperative projects, with international participants, both of which involve Charpy V-notch impact tests with instrumented strikers of 2mm and 8mm radii. Two heats of A 533 grade B class I pressure vessel steel and a low upper-shelf (LUS) submerged-arc (SA) weld were tested on the same Charpy machine, while one heat of a Russian Cr-Mo-V forging steel and a high upper-shelf (HUS) SA weld were tested on two different machines. The number of replicate tests at any one temperature ranged from 2 to 46 specimens. Prior to testing with each striker, verification specimens at the low, high, and super high energy levels from the National Institute of Standards and Technology (NIST) were tested. In the two series of verification tests, the tests with the 2mm striker met the requirements at the low and high energy levels but not at the super high energy. For one plate, the 2mm striker showed somewhat higher average absorbed energies than those for the 8-mm striker at all three test temperatures. For the second plate and the LUS weld, however, the 2mm striker showed somewhat lower energies at both test temperatures. For the Russian forging steel and the HUS weld, tests were conducted over a range of temperatures with tests at one laboratory using the 8mm striker and tests at a second laboratory using the 2mm striker. Lateral expansion was measured for all specimens and the results are compared with the absorbed energy results. The overall results showed generally good agreement (within one standard deviation) in energy measurements by the two strikers. Load-time traces from the instrumented strikers were also compared and used to estimate shear fracture percentage. Four different formulas from the European Structural Integrity Society draft standard for instrumented Charpy test are compared and a new formula is proposed for estimation of percent shear from the force-time trace

Design of specimen for weld residual stress simulation

International Nuclear Information System (INIS)

Kim, Jin Weon; Park, Jong Sun; Lee, Kyung Soo

2008-01-01

The objective of this study is to design a laboratory specimen for simulating residual stress of circumferential butt welding of pipe. Specimen type and method for residual stress generation were proposed based on the review of prior studies and parametric finite element simulation. To prove the proposed specimen type and loading method, the residual stress was generated using the designed specimen by applying proposed method and was measured. The measured residual stress using X-ray diffraction reasonably agreed with the results of finite element simulation considered in the specimen design. Comparison of residual strains measured at several locations of specimen and given by finite element simulation also showed good agreement. Therefore, it is indicated that the designed specimen can reasonably simulate the residual stress of circumferential butt welding of pipe

Characterization of impact behaviour of armour plate materials

Science.gov (United States)

Bassim, M. N.; Bolduc, M.; Nazimuddin, G.; Delorme, J.; Polyzois, I.

2012-08-01

Three armour plate materials, including two steels, namely HHA and Mars 300, and an aluminium alloy 5083, were studied under impact loading to determine their behaviour and the mechanisms of deformation that lead to failure. The experimental testing was carried out using either a direct impact compression Split Hopkinson Bar or a torsion Hopkinson Bar. The impact properties and stress-strain cures were obtained as a function of the impact momentum in compression and the angle of twist in torsion. It was found that at the high strain rates developed in the specimen during the tests, the deformation occurs by the formation of adiabatic shear bands (ASBs) which may lead to the formation of cracks within the bands and the ultimate failure of the specimens. It was also found that below a certain impact momentum, the deformation is more uniform and no ASBs are formed. Also, ASBs are more likely to form in the BCC metals such as the two steels while diffuse ASBs associated with plastic flow are exhibited in the 5083 aluminum alloy. Microstructural techniques ranging from optical microscopy to atomic force microscopy (AFM) were used to study the topography of the ASBs. Also, modelling of the formation was performed. The results provide a comprehensive understanding of the role of ASBs in the failure of these materials.

Characterization of impact behaviour of armour plate materials

Directory of Open Access Journals (Sweden)

Nazimuddin G.

2012-08-01

Full Text Available Three armour plate materials, including two steels, namely HHA and Mars 300, and an aluminium alloy 5083, were studied under impact loading to determine their behaviour and the mechanisms of deformation that lead to failure. The experimental testing was carried out using either a direct impact compression Split Hopkinson Bar or a torsion Hopkinson Bar. The impact properties and stress-strain cures were obtained as a function of the impact momentum in compression and the angle of twist in torsion. It was found that at the high strain rates developed in the specimen during the tests, the deformation occurs by the formation of adiabatic shear bands (ASBs which may lead to the formation of cracks within the bands and the ultimate failure of the specimens. It was also found that below a certain impact momentum, the deformation is more uniform and no ASBs are formed. Also, ASBs are more likely to form in the BCC metals such as the two steels while diffuse ASBs associated with plastic flow are exhibited in the 5083 aluminum alloy. Microstructural techniques ranging from optical microscopy to atomic force microscopy (AFM were used to study the topography of the ASBs. Also, modelling of the formation was performed. The results provide a comprehensive understanding of the role of ASBs in the failure of these materials.

TEM specimen preparation of semiconductor-PMMA-metal interfaces

International Nuclear Information System (INIS)

Thangadurai, P.; Lumelsky, Yulia; Silverstein, Michael S.; Kaplan, Wayne D.

2008-01-01

Transmission electron microscopy (TEM) cross-section specimens of PMMA in contact with gold and Si were prepared by focused ion beam (FIB) and compared with plan-view PMMA specimens prepared by a dip-coating technique. The specimens were characterized by TEM and electron energy loss spectroscopy (EELS). In the cross-section specimens, the thin films of PMMA were located in a Si-PMMA-Au multilayer. Different thicknesses of PMMA films were spin-coated on the Si substrates. The thickness of the TEM specimens prepared by FIB was estimated using EELS to be 0.65 of the plasmon mean-free-path. Along the PMMA-Au interface, Au particle diffusion into the PMMA was observed, and the size of the Au particles was in the range of 2-4 nm. Dip-coating of PMMA directly on Cu TEM grids resulted in thin specimens with a granular morphology, with a thickness of 0.58 of the plasmon mean-free-path. The dip-coated specimens were free from ion milling induced artifacts, and thus serve as control specimens for comparison with the cross-sectioned specimens prepared by FIB

The technique for determination of surface contamination by uranium on U3Si2-Al plate-type fuel elements

International Nuclear Information System (INIS)

Li Shulan; He Fengqi; Wang Qingheng; Han Jingquan

1993-04-01

The NDT method for determining the surface contamination by uranium on U 3 Si 2 -Al plate-type fuel elements, the process of standard specimen preparation and the graduation curve are described. The measurement results of U 3 Si 2 -Al plate-type fuel elements show that the alpha counting method to measure the surface contamination by uranium on fuel plate is more reliable. The UB-1 type surface contamination meter, which was recently developed, has many advantages such as high sensitivity to determine the uranium pollution, short time in measuring, convenience for operation, and the minimum detectable amount of uranium is 5 x 10 -10 g/cm 2 . The measuring device is controlled by a microcomputer. Besides data acquisition and processing, it has functions of statistics, output data on terminal or to printer and alarm. The procedures of measurement are fully automatic. All of these will meet the measuring needs in batch process

Evaluation of Electroless-Nickel Plated Polypropylene under Thermal Cycling and Mechanical Tests

Directory of Open Access Journals (Sweden)

O.O. Ajibola

2016-09-01

Full Text Available The electroless-nickel composite (ENC consisting of bright metallic electroless-nickel (EN and dull electroless-nickel-phosphorus (EN-P were deposited on the polypropylene (PP substrate from the sodium hypophosphite baths. The ENC plated specimens were subjected to abrasive wear-adhesion test of 1750, 3500, 7000 and 14000 cycles; thermal cycle-adhesion tests, and tensile strength and creep tests. The deposition of ENC influenced the strength and creep strain properties of the PP. The maximum stress σ of 118 (MPa was obtained from EN-PP specimen at strain  of 0.1 mm/mm as compared with the PP having stress σ of 36 (MPa at strain  of 0.07 mm/mm before failure The surface appearances and microstructures of ENC film on PP substrates were examined under the higher resolution metallurgical microscope with digital camera and microscopic camera. The composition of ENC film was characterized using Scanning Electron Microscopy and Energy Dispersive X-Ray analyses (Jeol JSM-7600F Field Emission SEM/EDX, The micrographs and spectra lines data generated were used to interpret the results.

Plate removal following orthognathic surgery.

Science.gov (United States)

Little, Mhairi; Langford, Richard Julian; Bhanji, Adam; Farr, David

2015-11-01

The objectives of this study are to determine the removal rates of orthognathic plates used during orthognathic surgery at James Cook University Hospital and describe the reasons for plate removal. 202 consecutive orthognathic cases were identified between July 2004 and July 2012. Demographics and procedure details were collected for these patients. Patients from this group who returned to theatre for plate removal between July 2004 and November 2012 were identified and their notes were analysed for data including reason for plate removal, age, smoking status, sex and time to plate removal. 3.2% of plates were removed with proportionally more plates removed from the mandible than the maxilla. 10.4% of patients required removal of one or more plate. Most plates were removed within the first post-operative year. The commonest reasons for plate removal were plate exposure and infection. The plate removal rates in our study are comparable to those seen in the literature. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Evaluation of irradiated coating material specimens

International Nuclear Information System (INIS)

Lee, Yong Jin; Nam, Seok Woo; Cho, Lee Moon

2007-12-01

Evaluation result of irradiated coating material specimens - Coating material specimens radiated Gamma Energy(Co 60) in air condition. - Evaluation conditions was above 1 X 10 4 Gy/hr, and radiated TID 2.0 X 10 6 Gy. - The radiated coating material specimens, No Checking, Cracking, Flaking, Delamination, Peeling and Blistering. - Coating system at the Kori no. 1 and APR 1400 Nuclear power plant, evaluation of irradiated coating materials is in accordance with owner's requirement(2.0 X 10 6 Gy)

Integration of Value Stream Map and Healthcare Failure Mode and Effect Analysis into Six Sigma Methodology to Improve Process of Surgical Specimen Handling.

Science.gov (United States)

Hung, Sheng-Hui; Wang, Pa-Chun; Lin, Hung-Chun; Chen, Hung-Ying; Su, Chao-Ton

2015-01-01

Specimen handling is a critical patient safety issue. Problematic handling process, such as misidentification (of patients, surgical site, and specimen counts), specimen loss, or improper specimen preparation can lead to serious patient harms and lawsuits. Value stream map (VSM) is a tool used to find out non-value-added works, enhance the quality, and reduce the cost of the studied process. On the other hand, healthcare failure mode and effect analysis (HFMEA) is now frequently employed to avoid possible medication errors in healthcare process. Both of them have a goal similar to Six Sigma methodology for process improvement. This study proposes a model that integrates VSM and HFMEA into the framework, which mainly consists of define, measure, analyze, improve, and control (DMAIC), of Six Sigma. A Six Sigma project for improving the process of surgical specimen handling in a hospital was conducted to demonstrate the effectiveness of the proposed model.

Biomechanical properties of an advanced new carbon/flax/epoxy composite material for bone plate applications.

Science.gov (United States)

Bagheri, Zahra S; El Sawi, Ihab; Schemitsch, Emil H; Zdero, Rad; Bougherara, Habiba

2013-04-01

This work is part of an ongoing program to develop a new carbon fiber/flax/epoxy (CF/flax/epoxy) hybrid composite material for use as an orthopaedic long bone fracture plate, instead of a metal plate. The purpose of this study was to evaluate the mechanical properties of this new novel composite material. The composite material had a "sandwich structure", in which two thin sheets of CF/epoxy were attached to each outer surface of the flax/epoxy core, which resulted in a unique structure compared to other composite plates for bone plate applications. Mechanical properties were determined using tension, three-point bending, and Rockwell hardness tests. Also, scanning electron microscopy (SEM) was used to characterize the failure mechanism of specimens in tension and three-point bending tests. The results of mechanical tests revealed a considerably high ultimate strength in both tension (399.8MPa) and flexural loading (510.6MPa), with a higher elastic modulus in bending tests (57.4GPa) compared to tension tests (41.7GPa). The composite material experienced brittle catastrophic failure in both tension and bending tests. The SEM images, consistent with brittle failure, showed mostly fiber breakage and fiber pull-out at the fractured surfaces with perfect bonding at carbon fibers and flax plies. Compared to clinically-used orthopaedic metal plates, current CF/flax/epoxy results were closer to human cortical bone, making the material a potential candidate for use in long bone fracture fixation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Measurements and Counts for Notacanthidae Specimens

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Taxonomic data were collected for specimens of deep-sea spiny eels (Notacanthidae) from the Hawaiian Ridge by Bruce C. Mundy. Specimens were collected off the north...

Bending and stretching of plates

CERN Document Server

Mansfield, E H; Hemp, W S

1964-01-01

The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

Notch effects in uniaxial tension specimens

International Nuclear Information System (INIS)

Delph, T.J.

1979-03-01

Results of a literature survey on the effect of notches on the time-dependent failure of uniaxial tension specimens at elevated temperatures are presented. Particular attention is paid to the failure of notched specimens containing weldments

Biomechanical investigation of an alternative concept to angular stable plating using conventional fixation hardware

Directory of Open Access Journals (Sweden)

Radtke Roman

2010-05-01

Full Text Available Abstract Background Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence" utilizing conventional (non-locked implants in comparison to conventional LC-DCP (limited contact dynamic compression plate and LCP (locking compression plate stabilization, in a human cadaveric diaphyseal gap model. Methods In eight pairs of human cadaveric femora, one femur per pair was randomly assigned to receive a Fence construct with either elevated or non-elevated plate, while the contralateral femur received either an LCP or LC-DCP instrumentation. Fracture gap motion and fatigue performance under cyclic loading was evaluated successively in axial compression and in torsion. Results were statistically compared in a pairwise setting. Results The elevated Fence constructs allowed significantly higher gap motion compared to the LCP instrumentations (axial compression: p ≤ 0.011, torsion p ≤ 0.015 but revealed similar performance under cyclic loading (p = 0.43. The Fence instrumentation with established bone-plate contact revealed larger fracture gap motion under axial compression compared to the conventional LC-DCP osteosynthesis (p ≤ 0.017. However, all contact Fence specimens survived the cyclic test, whereas all LC-DCP constructs failed early during torsion testing (p Conclusions Even though accentuated fracture gap motion became obvious, the "Fence" technique is considered an alternative to cost-intensive locking-head devices. The concept can be of interest in cases were angle-stable implants are unavailable and can lead to new strategies in implant design.

Numerical investigation of 3-D constraint effects on brittle fracture in SE(B) and C(T) specimens

International Nuclear Information System (INIS)

Nevalainen, M.; Dodds, R.H. Jr.

1996-07-01

This investigation employs 3-D nonlinear finite element analyses to conduct an extensive parametric evaluation of crack front stress triaxiality for deep notch SE(B) and C(T) specimens and shallow notch SE(B) specimens, with and without side grooves. Crack front conditions are characterized in terms of J-Q trajectories and the constraint scaling model for cleavage fracture toughness proposed previously by Dodds and Anderson. The 3-D computational results imply that a significantly less strict size/deformation limit, relative to the limits indicated by previous plane-strain computations, is needed to maintain small-scale yielding conditions at fracture by a stress- controlled, cleavage mechanism in deep notch SE(B) and C(T) specimens. Additional new results made available from the 3-D analyses also include revised η-plastic factors for use in experimental studies to convert measured work quantities to thickness average and maximum (local) J-values over the crack front

Technique of manufacturing specimen of irradiated fuel rods

International Nuclear Information System (INIS)

Min, Duck Seok; Seo, Hang Seok; Min, Duck Kee; Koo, Dae Seo; Lee, Eun Pyo; Yang, Song Yeol

1999-04-01

Technique of manufacturing specimen of irradiated fuel rods to perform efficient PIE is developed by analyzing the relation between requiring time of manufacturing specimen and manufacturing method in irradiated fuel rods. It takes within an hour to grind 1 mm of specimen thickness under 150 rpm in speed of grinding, 600 g gravity in force using no.120, no.240, no.320 of grinding paper. In case of no.400 of grinding paper, it takes more an hour to grind the same thickness as above. It takes up to a quarter to grind 80-130 μm in specimen thickness using no.400 of grinding paper. When grinding time goes beyond 15 minutes, the grinding thickness of specimen does not exist. The polishing of specimen with 150 Rpms in speed of grinding machine, 600 g gravity in force, 10 minutes in polishing time using diamond paste 15 μm on polishing cloths amounts to 50 μm in specimen thickness. In case of diamond paste 9 μm on polishing cloth, the polishing of specimen amounts to 20 μm. The polishing thickness of specimen with 15 minutes in polishing time using 6 μm, 3 μm, 1 μm, 1/4 μm does not exist. Technique of manufacturing specimen of irradiated fuel rods will have application to the destructive examination of PIE. (author). 6 refs., 1 tab., 10 figs

COMPARATIVE FIELD EXPERIMENTAL INVESTIGATIONS OF DIFFERENT FLAT PLATE SOLAR COLLECTORS

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Guangming Chen

2015-12-01

Full Text Available Full-scale traditional metal solar collectors and solar collector specimens fabricated from polymeric materials were investigated in the present study. A polymeric collector is 67.8% lighter than a traditional metal solar collector, and a metal solar collector with transparent plastic covering is 40.3% lighter than a traditional metal solar collector. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. A test rig for the natural circulation of the working fluid in a solar collector was built for a comparative experimental investigation of various solar collectors operating at ambient conditions. It was shown experimentally that the efficiency of a polymeric collector is 8–15% lower than the efficiency of a traditional collector.

Specimen loading list for the varying temperature experiment

International Nuclear Information System (INIS)

Qualls, A.L.; Sitterson, R.G.

1998-01-01

The varying temperature experiment HFIR-RB-13J has been assembled and inserted in the reactor. Approximately 5300 specimens were cleaned, inspected, matched, and loaded into four specimen holders. A listing of each specimen loaded into the steady temperature holder, its position in the capsule, and the identification of the corresponding specimen loaded into the varying temperature holder is presented in this report

Evaluation of Steel Shear Walls Behavior with Sinusoidal and Trapezoidal Corrugated Plates

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Emad Hosseinpour

2015-01-01

Full Text Available Reinforcement of structures aims to control the input energy of unnatural and natural forces. In the past four decades, steel shear walls are utilized in huge constructions in some seismic countries such as Japan, United States, and Canada to lessen the risk of destructive forces. The steel shear walls are divided into two types: unstiffened and stiffened. In the former, a series of plates (sinusoidal and trapezoidal corrugated with light thickness are used that have the postbuckling field property under overall buckling. In the latter, steel profile belt series are employed as stiffeners with different arrangement: horizontal, vertical, or diagonal in one side or both sides of wall. In the unstiffened walls, increasing the thickness causes an increase in the wall capacity under large forces in tall structures. In the stiffened walls, joining the stiffeners to the wall is costly and time consuming. The ANSYS software was used to analyze the different models of unstiffened one-story steel walls with sinusoidal and trapezoidal corrugated plates under lateral load. The obtained results demonstrated that, in the walls with the same dimensions, the trapezoidal corrugated plates showed higher ductility and ultimate bearing compared to the sinusoidal corrugated plates.

Experimental and numerical investigation of the mixed-mode delamination in Arcan laminated specimens

International Nuclear Information System (INIS)

Choupani, Naghdali

2008-01-01

This paper investigates mixed-mode interlaminar fracture behaviour in woven carbon fibre/polyetherimide (CF/PEI) thermoplastic composite material based on experimental and numerical analyses. Experiments were conducted on modified Arcan specimens using the special test loading device. By varying the loading angle from 0 o to 90 o , pure mode-I, pure mode-II and a wide range of mixed-mode data were obtained experimentally. Using the finite-element results, correction factors were applied to the CF/PEI fracture specimen. By employing experimentally measured critical loads and the aid of the finite-element method, mixed-mode interlaminar fracture toughness for the composite under consideration determined. The failure response of CF/PEI composite was compared to the different mixed-mode failure criteria, and the best criterion was selected. The fracture surfaces of the CF/PEI composite under different mixed-mode loading conditions were examined by optical and scanning electron microscopy to gain insight into the failure responses

Cluster analysis in soft X-ray spectromicroscopy: Finding the patterns in complex specimens

Energy Technology Data Exchange (ETDEWEB)

Lerotic, M. [Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, NY 11794-3800 (United States)]. E-mail: lerotic@xray1.physics.sunysb.edu; Jacobsen, C. [Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, NY 11794-3800 (United States); Gillow, J.B. [Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Francis, A.J. [Environmental Sciences Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Wirick, S. [Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, NY 11794-3800 (United States); Vogt, S. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Maser, J. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

2005-06-15

Soft X-ray spectromicroscopy provides spectral data on the chemical speciation of light elements at sub-100 nanometer spatial resolution. If all chemical species in a specimen are known and separately characterized, existing approaches can be used to measure the concentration of each component at each pixel. In other situations such as in biology or environmental science, this approach may not be possible. We have previously described [M. Lerotic, C. Jacobsen, T. Schaefer, S. Vogt, Ultramicroscopy 100 (1-2) (2004) 35] the use of principle component analysis (PCA) to orthogonalize and noise-filter spectromicroscopy data, and cluster analysis (Canada) to classify the analyzed data and obtain thickness maps of representative spectra. We describe here an extension of that work employing an angle distance measure; this measure provides better classification based on spectral signatures alone in specimens with significant thickness variations. The method is illustrated using simulated data, and also to examine sporulation in the bacterium Clostridium sp.

Recent advances on Charpy specimen reconstitution techniques

Energy Technology Data Exchange (ETDEWEB)

Andrade, Arnaldo H.P.; Lobo, Raquel M.; Miranda, Carlos Alexandre J., E-mail: aandrade@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-07-01

Charpy specimen reconstitution is widely used around the world as a tool to enhance or supplement surveillance programs of nuclear reactor pressure vessels. The reconstitution technique consists in the incorporation of a small piece from a previously tested specimen into a compound specimen, allowing to increase the number of tests. This is especially important if the available materials is restricted and fracture mechanics parameter have to be determined. The reconstitution technique must fulfill some demands, among them tests results like the original standard specimens and the loaded material of the insert must not be influenced by the welding and machining procedure. It is known that reconstitution of Charpy specimens may affect the impact energy in a consequence of the constraint of plastic deformation by the hardened weldment and HAZ. This paper reviews some recent advances of the reconstitution technique and its applications. (author)

Recent advances on Charpy specimen reconstitution techniques

International Nuclear Information System (INIS)

Andrade, Arnaldo H.P.; Lobo, Raquel M.; Miranda, Carlos Alexandre J.

2017-01-01

Charpy specimen reconstitution is widely used around the world as a tool to enhance or supplement surveillance programs of nuclear reactor pressure vessels. The reconstitution technique consists in the incorporation of a small piece from a previously tested specimen into a compound specimen, allowing to increase the number of tests. This is especially important if the available materials is restricted and fracture mechanics parameter have to be determined. The reconstitution technique must fulfill some demands, among them tests results like the original standard specimens and the loaded material of the insert must not be influenced by the welding and machining procedure. It is known that reconstitution of Charpy specimens may affect the impact energy in a consequence of the constraint of plastic deformation by the hardened weldment and HAZ. This paper reviews some recent advances of the reconstitution technique and its applications. (author)

Electro-mechanical vibration analysis of functionally graded piezoelectric porous plates in the translation state

Science.gov (United States)

Wang, Yan Qing

2018-02-01

To provide reference for aerospace structural design, electro-mechanical vibrations of functionally graded piezoelectric material (FGPM) plates carrying porosities in the translation state are investigated. A modified power law formulation is employed to depict the material properties of the plates in the thickness direction. Three terms of inertial forces are taken into account due to the translation of plates. The geometrical nonlinearity is considered by adopting the von Kármán non-linear relations. Using the d'Alembert's principle, the nonlinear governing equation of the out-of-plane motion of the plates is derived. The equation is further discretized to a system of ordinary differential equations using the Galerkin method, which are subsequently solved via the harmonic balance method. Then, the approximate analytical results are validated by utilizing the adaptive step-size fourth-order Runge-Kutta technique. Additionally, the stability of the steady state responses is examined by means of the perturbation technique. Linear and nonlinear vibration analyses are both carried out and results display some interesting dynamic phenomenon for translational porous FGPM plates. Parametric study shows that the vibration characteristics of the present inhomogeneous structure depend on several key physical parameters.

Copper electrodeposition from an acidic plating bath containing accelerating and inhibiting organic additives

International Nuclear Information System (INIS)

Pasquale, M.A.; Gassa, L.M.; Arvia, A.J.

2008-01-01

Copper electrodeposition on copper from still plating solutions of different compositions was investigated utilising electrochemical impedance spectroscopy (EIS), cyclic voltammetry, and scanning electron microscopy (SEM). An acid copper sulphate plating base solution was employed either with or without sodium chloride in the presence of a single additive, either polyethylene glycol (PEG) or 3-mercapto-2-propanesulphonic acid (MPSA), and their mixture. Thallium underpotential deposition/anodic stripping was employed to determine the adsorption capability of additives on copper. In the absence of chloride ions, MPSA shows a moderate adsorption on copper, whereas PEG is slightly adsorbed. At low cathodic overpotentials, the simultaneous presence of MPSA and chloride ions accelerates copper electrodeposition through the formation of an MPSA-chloride ion complex in the solution, particularly for about 220 μM sodium chloride. The reverse effect occurs in PEG-sodium chloride plating solutions. In this case, from EIS data the formation of a film that interferes with copper electrodeposition can be inferred. At higher cathodic overpotentials, when copper electrodeposition is under mass transport control, the cathode coverage by a PEG-copper chloride-mediated film becomes either partially or completely detached as the concentration of chloride ions at the negatively charged copper surface diminishes. The copper cathode grain topography at the μm scale depends on the cathodic overpotential, plating solution composition and average current density. Available data about the solution constituents and their adsorption on copper make it possible to propose a likely complex mechanism to understand copper electrodeposition from these media, including the accelerating effect of MPSA and the dynamics of PEG-copper chloride complex adsorbate interfering with the surface mobility of depositing copper ad-ions/ad-atoms

The Ritz - Sublaminate Generalized Unified Formulation approach for piezoelectric composite plates

Science.gov (United States)

D'Ottavio, Michele; Dozio, Lorenzo; Vescovini, Riccardo; Polit, Olivier

2018-01-01

This paper extends to composite plates including piezoelectric plies the variable kinematics plate modeling approach called Sublaminate Generalized Unified Formulation (SGUF). Two-dimensional plate equations are obtained upon defining a priori the through-thickness distribution of the displacement field and electric potential. According to SGUF, independent approximations can be adopted for the four components of these generalized displacements: an Equivalent Single Layer (ESL) or Layer-Wise (LW) description over an arbitrary group of plies constituting the composite plate (the sublaminate) and the polynomial order employed in each sublaminate. The solution of the two-dimensional equations is sought in weak form by means of a Ritz method. In this work, boundary functions are used in conjunction with the domain approximation expressed by an orthogonal basis spanned by Legendre polynomials. The proposed computational tool is capable to represent electroded surfaces with equipotentiality conditions. Free-vibration problems as well as static problems involving actuator and sensor configurations are addressed. Two case studies are presented, which demonstrate the high accuracy of the proposed Ritz-SGUF approach. A model assessment is proposed for showcasing to which extent the SGUF approach allows a reduction of the number of unknowns with a controlled impact on the accuracy of the result.

Improvement of visualization efficiency for the nondestructive inspection image of internal defects in plate type nuclear fuel

International Nuclear Information System (INIS)

Park, Seung Kyu; Park, Nak Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cheong, Yong Moo; Kang, Young June

2012-01-01

Plate type nuclear fuel has been adopted in most research reactors. The production quality of the fuel is a key part for an efficient and stable generation of thermal energy in research reactors. Thus, a nondestructive quality inspection for the internal defects of plate type nuclear fuel is a key process during the production of nuclear fuel for safety insurance. Nondestructive quality inspections based on X rays and ultrasounds have been widely used for the defect detection of plate type nuclear fuel. X ray testing is a simple and fast inspection method, and provides an image in real time as the inspection results. Thus, the testing can be carried out by a non expert field worker. However, it is hard to detect closed type defects that should be detected during the production of plate type nuclear fuel. Ultrasonic testing is a powerful tool to detect internal defects including open type and closed type defects in plate type nuclear fuel. However, the inspection process is complicated because an immersion test should be carried out in a water tank. It is also a time consuming inspection method because area testing to acquire image is based on the scanning of the point by point inspections. Among nondestructive inspection techniques, the techniques based on laser interferometry and infrared thermography have been widely used in the detection of internal defects of plate type composite materials, such as aircraft, automotive etc. While infrared thermography technique (IRT) analyses the thermal behavior of the specimen surface, laser interferometry technique (LIT) analyses the deformation field. Both techniques are useful tools for detection and evaluation of internal defects in composite materials. Especially, the laser interferometry technique can provide the depth information of internal defects. Laser interferometry technique (LIT) is a non contact inspection method faster than thermography. Also, this technique requires less energy than thermography and the

Assessing the role of slab rheology in coupled plate-mantle convection models

Science.gov (United States)

Bello, Léa; Coltice, Nicolas; Tackley, Paul J.; Dietmar Müller, R.; Cannon, John

2015-11-01

Reconstructing the 3D structure of the Earth's mantle has been a challenge for geodynamicists for about 40 yr. Although numerical models and computational capabilities have substantially progressed, parameterizations used for modeling convection forced by plate motions are far from being Earth-like. Among the set of parameters, rheology is fundamental because it defines in a non-linear way the dynamics of slabs and plumes, and the organization of lithosphere deformation. In this study, we evaluate the role of the temperature dependence of viscosity (variations up to 6 orders of magnitude) and the importance of pseudo-plasticity on reconstructing slab evolution in 3D spherical models of convection driven by plate history models. Pseudo-plasticity, which produces plate-like behavior in convection models, allows a consistent coupling between imposed plate motions and global convection, which is not possible with temperature-dependent viscosity alone. Using test case models, we show that increasing temperature dependence of viscosity enhances vertical and lateral coherence of slabs, but leads to unrealistic slab morphologies for large viscosity contrasts. Introducing pseudo-plasticity partially solves this issue, producing thin laterally and vertically more continuous slabs, and flat subduction where trench retreat is fast. We evaluate the differences between convection reconstructions employing different viscosity laws to be very large, and similar to the differences between two models with the same rheology but using two different plate histories or initial conditions.

Integration of Value Stream Map and Healthcare Failure Mode and Effect Analysis into Six Sigma Methodology to Improve Process of Surgical Specimen Handling

Directory of Open Access Journals (Sweden)

Sheng-Hui Hung

2015-01-01

Full Text Available Specimen handling is a critical patient safety issue. Problematic handling process, such as misidentification (of patients, surgical site, and specimen counts, specimen loss, or improper specimen preparation can lead to serious patient harms and lawsuits. Value stream map (VSM is a tool used to find out non-value-added works, enhance the quality, and reduce the cost of the studied process. On the other hand, healthcare failure mode and effect analysis (HFMEA is now frequently employed to avoid possible medication errors in healthcare process. Both of them have a goal similar to Six Sigma methodology for process improvement. This study proposes a model that integrates VSM and HFMEA into the framework, which mainly consists of define, measure, analyze, improve, and control (DMAIC, of Six Sigma. A Six Sigma project for improving the process of surgical specimen handling in a hospital was conducted to demonstrate the effectiveness of the proposed model.

Method for measuring retardation of infrared wave-plate by modulated-polarized visible light

Science.gov (United States)

Zhang, Ying; Song, Feijun

2012-11-01

A new method for precisely measuring the optical phase retardation of wave-plates in the infrared spectral region is presented by using modulated-polarized visible light. An electro-optic modulator is used to accurately determine the zero point by the frequency-doubled signal of the Modulated-polarized light. A Babinet-Soleil compensator is employed to make the phase delay compensation. Based on this method, an instrument is set up to measure the retardations of the infrared wave-plates with visible region laser. Measurement results with high accuracy and sound repetition are obtained by simple calculation. Its measurement precision is less than and repetitive precision is within 0.3%.

Cadmium plating replacements

Energy Technology Data Exchange (ETDEWEB)

Nelson, M.J.; Groshart, E.C.

1995-03-01

The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

Analysis of the truth loading conditions of a austenitic CT specimen during a SCC experiment

International Nuclear Information System (INIS)

Marie, S.; Guerre, C.; Herms, E.

2012-01-01

With the aim to investigate the influence of strain hardening on the stainless steels susceptibility to stress corrosion cracking, tests were conducted in PWR environment on CT specimens, taken from a 316L stainless steel sheet cold rolled to 40% in thickness reduction. The initial cracks obtained by the fatigue pre-cracking have an atypical 'V' shape with smaller propagation in the center of the CT thickness compared to nominal propagation observed at both sides. The initial explanation was to consider a stress intensity factor derived from classical reference solution on the basis of a straight crack front, and considering the local value of the crack depth in the equation. This assumption raised several problems analyses in this paper. This particular shape of the initial defect may be related to several factors, and partly to the 40% cold rolling. It is likely that the hardening is not uniform, with a higher rate at the specimen sides than in the central area. In addition, significant residual stresses due to the gradient of mechanical properties are observed. Due to the high rate of work hardening by rolling of the sheet metal, a gradient of the mechanical properties through the thickness was determined, and the residual stresses profile induced by this process was measured. The variations obtained are consistent with each other: the material is more hardened in the vicinity of specimen surface and residual stresses are compressive in nature in the central part of the specimen and of tensile type on the flanks. All these data were firstly considered in order to assess their role regarding the particular form of the initial crack front obtained after fatigue: the 3D finite element calculations taking into account the true shape of the crack front demonstrate the relationship between the characteristics of the experimental crack front obtained after fatigue pre-cracking and the residual stresses. Moreover, from the residual stresses measured on the plate where

History of internal fixation with plates (part 2): new developments after World War II; compressing plates and locked plates.

Science.gov (United States)

Hernigou, Philippe; Pariat, Jacques

2017-07-01

The first techniques of operative fracture with plates were developed in the 19th century. In fact, at the beginning these methods consisted of an open reduction of the fracture usually followed by a very unstable fixation. As a consequence, the fracture had to be opened with a real risk of (sometimes lethal) infection, and due to unstable fixation, protection with a cast was often necessary. During the period between World Wars I and II, plates for fracture fixation developed with great variety. It became increasingly recognised that, because a fracture of a long bone normally heals with minimal resorption at the bone ends, this may result in slight shortening and collapse, so a very rigid plate might prevent such collapse. However, as a consequence, delayed healing was observed unless the patient was lucky enough to have the plate break. One way of dealing with this was to use a slotted plate in which the screws could move axially, but the really important advance was recognition of the role of compression. After the first description of compression by Danis with a "coapteur", Bagby and Müller with the AO improved the technique of compression. The classic dynamic compression plates from the 1970s were the key to a very rigid fixation, leading to primary bone healing. Nevertheless, the use of strong plates resulted in delayed union and the osteoporosis, cancellous bone, comminution, and/or pathological bone resulted in some failures due to insufficient stability. Finally, new devices represented by locking plates increased the stability, contributing to the principles of a more biological osteosynthesis while giving enough stability to allow immediate full weight bearing in some patients.

Effect of the fabrication process on fatigue performance of U3Si2 fuel plate with sandwich structure

International Nuclear Information System (INIS)

Wang Xishu; Li Shuangshou; Wang Qingyuan; Xu Yong

2005-01-01

U 3 Si 2 -Al fuel plate is one of the dispersion fuel structure materials recently developed and widely used in research reactors. The mechanical properties of this structural material, especially the fatigue performance, are strongly dependent on its fabrication process. To investigate the effects of these processing technologies, the fatigue tests for the different specimens were carried out. The S-N curves indicate that the fabrication processing technologies of U 3 Si 2 fuel plate, such as the addition of U 3 Si 2 particles into aluminum powder to form the fuel meat, holding and rolling the processes of meat and cladding of 6061-Al alloy, plays an important role in improving the mechanical properties and fatigue performance of this fuel plate. In addition, some factors that influence the crack initiation and propagation are summarized based on the fatigue images that are in situ observations with SEM. The critical criterion for fatigue damage is proposed based on the fatigue data of the structural material, which were obtained at the different conditions

Comparison of analysis and experimental data for a unique crack arrest specimen

International Nuclear Information System (INIS)

Ayres, D.J.; Fabi, R.J.; Schonenberg, R.Y.; Norris, D.M.

1988-01-01

A new fracture test specimen has been developed to study crack extension and arrest in nuclear reactor vessel steels subject to stress-intensity factor and toughness gradients similar to those in postulated pressurized thermal shock situations. A summary of the results of all the tests performed is presented to illustrate the range of crack arrest and crack reinitiation conditions observed. One test of this specimen with the corresponding stress analysis is described in detail. During this test the crack initiated, extended, arrested, reinitiated, extended again, and reached a final arrest. Comparison of detailed dynamic elastic-plastic finite-element analyses and dynamic strain and displacement measurements of the crack extension, arrest, and reinitiation events, combined with topographic analysis of the future surfaces, has led to a new understanding of the crack extension and arrest process. The results of the tests demonstrate crack arrest in rising stress-intensity field at near-upper-shelf temperature conditions and show that the toughness required for arrest is lower than would be predicted by the analysis procedures usually employed for pressurized thermal shock evaluations

Spectral isotopic methods of determining nitrogen and carbon in plant specimens with laser volatization

International Nuclear Information System (INIS)

Lazeeva, G.S.

1986-01-01

Methods have been devised for the local determination of nitrogen and carbon isotope compositions in plant specimens, which provide separate and joint determination. Local laser evaporation has been combined with spectroscopic determination of the isotope compositions in the gas phase. A continuous-wave CO 2 laser is preferable for the local evaporation; the carbon isotope composition may be determined directly on the sum of the evaporation products, whereas nitrogen must first be separated as N 2 . Methods have also been developed for the local determination of total nitrogen and carbon in a sample with isotope dilution on the basis of laser evaporation. In order to eliminate systematic errors in determining total carbon in plant material, an evaporation method free from a rim has been devised. These methods have been used in determining isotope concentration profiles in plant specimens grown in experiments employing labeled nitrogen and carbon

A preliminary study on the local impact behavior of Steel-plate Concrete walls

International Nuclear Information System (INIS)

Kim, Kap-sun; Moon, Il-hwan; Choi, Hyung-jin; Nam, Deok-woo

2017-01-01

International regulations for nuclear power plants strictly prescribe the design requirements for local impact loads, such as aircraft engine impact, and internal and external missile impact. However, the local impact characteristics of Steel-plate Concrete (SC) walls are not easy to evaluate precisely because the dynamic impact behavior of SC walls which include external steel plate, internal concrete, tie-bars, and studs, is so complex. In this study, dynamic impact characteristics of SC walls subjected to local missile impact load are investigated via actual high-speed impact test and numerical simulation. Three velocity checkout tests and four SC wall tests were performed at the Energetic Materials Research and Testing Center (EMRTC) site in the USA. Initial and residual velocity of the missile, strain and acceleration of the back plate, local failure mode (penetration, bulging, splitting and perforation) and deformation size, etc. were measured to study the local behavior of the specimen using high speed cameras and various other instrumentation devices. In addition, a more advanced and applicable numerical simulation method using the finite element (FE) method is proposed and verified by the experimental results. Finally, the experimental results are compared with the local failure evaluation formula for SC walls recently proposed, and future research directions for the development of a refined design method for SC walls are reviewed.

Fracture toughness measurements with subsize disk compact specimens

International Nuclear Information System (INIS)

Alexander, D.J.

1992-01-01

Special fixtures and test methods are necessary to facilitate the fracture toughness testing of small disk compact specimens of irradiated candidate materials for first-wall fusion applications. New methods have been developed for both the unloading compliance and potential drop techniques of monitoring crack growth. Provisions have been made to allow the necessary probes and instrumentation to be installed remotely using manipulators for testing of irradiated specimens in a hot cell. Laboratory trials showed that both unloading compliance and potential drop gave useful results. Both techniques gave similar data, and predicted the final crack extension within allowable limits. The results from the small disk compact specimens were similar to results from conventional compact specimen 12.7 mm thick. However, the slopes of the J-R curves from the larger specimens were lower, suggesting that the smaller disk compact specimens may have lost some constraint due to their size. The testing shows that it should be possible to generate useful J-R curve fracture toughness data from the small disk compact specimens

Fracture toughness measurements with subsize disk compact specimens

International Nuclear Information System (INIS)

Alexander, D.J.

1992-01-01

Special fixtures and test methods have been developed for testing small disk compact specimens (12.5 mm diam by 4.6 mm thick). Both unloading compliance and potential drop methods have been used to monitor crack extension during the J-integral resistance (J-R) curve testing. Provisions have been made to allow the necessary probes and instrumentation to be installed remotely using manipulators for testing of irradiated specimens in a hat cell. Laboratory trials showed that both unloading compliance and potential drop gave useful results. Both techniques gave similar data, and predicted the final crack extension within allowable limits. The results from the small disk compact specimens were similar to results from conventional compact specimens 12.7-mm thick. However, the slopes of the J-R curves from the larger specimens were lower, suggesting that the smaller disk compact specimens may have lost some constraint due to their size. The testing shows that it should be possible to generate useful J-R curve fracture toughness data from the small disk compact specimens

A solution for the Graetz problem in parallel plates, with axial heat conduction in the fluid and in the wall

International Nuclear Information System (INIS)

Biage, M.

1983-04-01

A heat transfer problem in parallel plates with infinite with has been solved, with axial heat conduction in the fluid and in the wall, considering steady-state laminar flow for a Newtonian fluid and a fully developed velocity profile. The duct consists of an infinite inicial part, insulated on both plates, an intermediale part of finite length, with a prescribed heat flux in the upper plate and insulated on the botton plate, and by another infinite part also insulated on both plates. The problem has been solved by a numerical combination of the integral equation method and the variational method. Both, the performance of the numerical technique employed and results obtained are analyzed in this work. It is demostrated that the heat conduction in the wall significantly modifies the heat transfer parameters. (Author) [pt

Nonlinear response arising from non self-similar crack growth in finite thickness plates

International Nuclear Information System (INIS)

Sih, G.C.; Chen, C.

1982-07-01

Described in this report is a three-dimensional finite element procedure for finding the stresses in a finite thickness plate with a through crack. The Mode I loading is increased incrementally such that crack growth occurs in segments. The individual crack profiles are assumed to coincide with the locations of minimum strain energy density, (dW/dV)/sub min/. Its shape is found to change during growth. Each successive crack growth increment will increase even though the rising load increment is kept constant. Three different plate thickness to half crack length ratios were analyzed. An average critical crack ligament distance r/sub c/ = 0.172 in (0.437 cm) being independent of crack and specimen size was obtained. This corresponds to an analytically predicted fracture toughness S/sub c/ = r/sub c/ (dW/dV)/sub c/ = 15.489 lb/in (2708.825 N/m) for A533B steel at -10 0 F. Data at low temperature were used in order to confine crack growth within the linear elastic range

High resolution SAW elastography for ex-vivo porcine skin specimen

Science.gov (United States)

Zhou, Kanheng; Feng, Kairui; Wang, Mingkai; Jamera, Tanatswa; Li, Chunhui; Huang, Zhihong

2018-02-01

Surface acoustic wave (SAW) elastography has been proven to be a non-invasive, non-destructive method for accurately characterizing tissue elastic properties. Current SAW elastography technique tracks generated surface acoustic wave impulse point by point which are a few millimeters away. Thus, reconstructed elastography has low lateral resolution. To improve the lateral resolution of current SAW elastography, a new method was proposed in this research. A M-B scan mode, high spatial resolution phase sensitive optical coherence tomography (PhS-OCT) system was employed to track the ultrasonically induced SAW impulse. Ex-vivo porcine skin specimen was tested using this proposed method. A 2D fast Fourier transform based algorithm was applied to process the acquired data for estimating the surface acoustic wave dispersion curve and its corresponding penetration depth. Then, the ex-vivo porcine skin elastogram was established by relating the surface acoustic wave dispersion curve and its corresponding penetration depth. The result from the proposed method shows higher lateral resolution than that from current SAW elastography technique, and the approximated skin elastogram could also distinguish the different layers in the skin specimen, i.e. epidermis, dermis and fat layer. This proposed SAW elastography technique may have a large potential to be widely applied in clinical use for skin disease diagnosis and treatment monitoring.

The Importance of Lower Mantle Structure to Plate Stresses and Plate Motions

Science.gov (United States)

Holt, W. E.; Wang, X.; Ghosh, A.

2016-12-01

Plate motions and plate stresses are widely assumed as the surface expression of mantle convection. The generation of plate tectonics from mantle convection has been studied for many years. Lithospheric thickening (or ridge push) and slab pull forces are commonly accepted as the major driving forces for the plate motions. However, the importance of the lower mantle to plate stresses and plate motions remains less clear. Here, we use the joint modeling of lithosphere and mantle dynamics approach of Wang et al. (2015) to compute the tractions originating from deeper mantle convection and follow the method of Ghosh et al. (2013) to calculate gravitational potential energy per unit area (GPE) based on Crust 1.0 (Laske et al., 2013). Absolute values of deviatoric stresses are determined by the body force distributions (GPE gradients and traction magnitudes applied at the base of the lithosphere). We use the same relative viscosity model that Ghosh et al. (2013) used, and we solve for one single adjustable scaling factor that multiplies the entire relative viscosity field to provide absolute values of viscosity throughout the lithosphere. This distribution of absolute values of lithosphere viscosities defines the magnitudes of surface motions. In this procedure, the dynamic model first satisfies the internal constraint of no-net-rotation of motions. The model viscosity field is then scaled by the single factor until we achieve a root mean square (RMS) minimum between computed surface motions and the kinematic no-net-rotation (NNR) model of Kreemer et al. (2006). We compute plate stresses and plate motions from recently published global tomography models (over 70 based on Wang et al., 2015). We find that RMS misfits are significantly reduced when details of lower mantle structure from the latest tomography models are added to models that contain only upper and mid-mantle density distributions. One of the key reasons is that active upwelling from the Large Low Shear

7 CFR 97.8 - Specimen requirements.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Specimen requirements. 97.8 Section 97.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... required by the examiner to furnish representative specimens of the variety, or its flower, fruit, or seeds...

Single-jet gas cooling of in-beam foils or specimens: Prediction of the convective heat-transfer coefficient

Science.gov (United States)

Steyn, Gideon; Vermeulen, Christiaan

2018-05-01

An experiment was designed to study the effect of the jet direction on convective heat-transfer coefficients in single-jet gas cooling of a small heated surface, such as typically induced by an accelerated ion beam on a thin foil or specimen. The hot spot was provided using a small electrically heated plate. Heat-transfer calculations were performed using simple empirical methods based on dimensional analysis as well as by means of an advanced computational fluid dynamics (CFD) code. The results provide an explanation for the observed turbulent cooling of a double-foil, Havar beam window with fast-flowing helium, located on a target station for radionuclide production with a 66 MeV proton beam at a cyclotron facility.

Residual stress improvement in multi-layer welded plates using water-shower cooling during welding process

International Nuclear Information System (INIS)

Yanagida, Nobuyoshi; Koide, Hiroo

2006-01-01

To reduce tensile residual stress in a welded region, we developed a new welding method that applies a water-shower behind the welding torch. When this method is applied to welding of austenitic stainless steel plates, cooling conditions mainly determine how much the residual stress can be reduced. To determine the conditions, we first used FEM to evaluate the effects of interpass temperature on the residual stress. And we found effective conditions for reducing tensile residual stress. To verify the validity of the conditions, specimens welded with or without water shower cooling were manufactured. Residual stresses of the specimens were experimentally measured. It was found that tensile residual stresses were generated on the surface of the welds and those were reduced in the case that the water-shower was applied. These measurement results agree well with the FEM analyses. It can therefore be concluded that the water-shower cooling during welding is appropriate for reducing tensile residual stress in austenitic stainless steel welding. (author)

Displacement tracking in single human trabecula with metal-plated micro-spheres using X-ray radiography imaging

International Nuclear Information System (INIS)

Jiroušek, O; Kytýř, D; Doktor, T; Dammer, J; Krejčí, F

2013-01-01

This study presents an improved radiographic method for strain measurement in very small samples of a single trabeculae. X-ray micro-radiography was used to track the deformation behaviour of individual trabecula during mechanical loading. As the X-ray micro-radiography images of a single trabecula show no significant features applicable for digital image correlation (DIC) a random pattern of markers was created on the surfaces of the samples to improve the accuracy of tracking. Metal plated borosilicate glassmicro-spheres (mean diameter 10 μm) were used as the markers for trabecular displacement tracking. Two different X-ray imaging setups were used for this purpose. The specimens of isolated trabeculae were loaded by a micro-mechanical testing device developed with respect to radiographical observation. This compact device enables a high precision three-point bending measurement. The specimen was continuously irradiated during the loading procedure by a micro-focus X-ray source. The radiographs were acquired by a single-photon counting silicon pixel detector and s flat panel sensor with CsI flipped scintillator plate. Circular Hough transform was used to locate positions of the spherical markers in the sequence of acquired radiographs and to calculate the strain in the loaded sample. The gold-coated micro-spheres provide clearly visible features in the sequence of radiographs after beam hardening correction, which in conjunction with pattern recognition algorithm enables to substantially improve the accuracy of strain measurements.

Catalysts characteristics of Ni/YSZ core-shell according to plating conditions using electroless plating

Science.gov (United States)

Park, Hyun-Wook; Jang, Jae-Won; Lee, Young-Jin; Kim, Jin-Ho; Jeon, Dae-Woo; Lee, Jong-Heun; Hwang, Hae-jin; Lee, Mi-Jai

2017-11-01

This study aims to develop an anode catalyst for a solid oxide fuel cell (SOFC) using electroless nickel plating. We have proposed a new method for electroless plating of Ni metal on yttria-stabilized zirconia (YSZ) particles. We examine the uniformity of the Ni layer on the plated core-shell powder, in addition to the content of Ni and the reproducibility of the plating. We have also evaluated the carbon deposition rate and characteristics of the SOFC anode catalyst. To synthesize Ni-plated YSZ particles, the plated powder is heat-treated at 1200 °C. The resultant particles, which have an average size of 50 μm, were subsequently used in the experiment. The size of the Ni particles and the Ni content both increase with increasing plating temperature and plating time. The X-ray diffraction pattern reveals the growth of Ni particles. After heat-treatment, Ni is oxidized to NiO, leading to the co-existence of Ni and NiO; Ni3P is also observed due to the presence of phosphorous in the plating solution. Following heat treatment for 1 h at 1200 °C, Ni is mostly oxidized to NiO. The carbon deposition rate of the reference YSZ powder is 135%, while that of the Ni-plated YSZ is 1%-6%.

HER2 testing on core needle biopsy specimens from primary breast cancers: interobserver reproducibility and concordance with surgically resected specimens

International Nuclear Information System (INIS)

Tsuda, Hitoshi; Kurosumi, Masafumi; Umemura, Shinobu; Yamamoto, Sohei; Kobayashi, Takayuki; Osamura, Robert Yoshiyuki

2010-01-01

Accurate evaluation of human epidermal growth factor receptor type-2 (HER2) status based on core needle biopsy (CNB) specimens is mandatory for identification of patients with primary breast cancer who will benefit from primary systemic therapy with trastuzumab. The aim of the present study was to validate the application of HER2 testing with CNB specimens from primary breast cancers in terms of interobserver reproducibility and comparison with surgically resected specimens. A total of 100 pairs of archival formalin-fixed paraffin-embedded CNB and surgically resected specimens of invasive breast carcinomas were cut into sections. All 100 paired sections were subjected to HER2 testing by immunohistochemistry (IHC) and 27 paired sections were subjected to that by fluorescence in situ hybridization (FISH), the results being evaluated by three and two observers, respectively. Interobserver agreement levels in terms of judgment and the concordance of consensus scores between CNB samples and the corresponding surgically resected specimens were estimated as the percentage agreement and κ statistic. In CNB specimens, the percentage interobserver agreement of HER2 scoring by IHC was 76% (κ = 0.71) for 3 × 3 categories (0-1+ versus 2+ versus 3+) and 90% (κ = 0.80) for 2 × 2 categories (0-2+ versus 3+). These levels were close to the corresponding ones for the surgically resected specimens: 80% (κ = 0.77) for 3 × 3 categories and 92% (κ = 0.88) for 2 × 2 categories. Concordance of consensus for HER2 scores determined by IHC between CNB and the corresponding surgical specimens was 87% (κ = 0.77) for 3 × 3 categories, and 94% (κ = 0.83) for 2 × 2 categories. Among the 13 tumors showing discordance in the mean IHC scores between the CNB and surgical specimens, the results of consensus for FISH results were concordant in 11. The rate of successful FISH analysis and the FISH positivity rate in cases with a HER2 IHC score of 2+ differed among specimens processed at

HER2 testing on core needle biopsy specimens from primary breast cancers: interobserver reproducibility and concordance with surgically resected specimens

Directory of Open Access Journals (Sweden)

Yamamoto Sohei

2010-10-01

Full Text Available Abstract Background Accurate evaluation of human epidermal growth factor receptor type-2 (HER2 status based on core needle biopsy (CNB specimens is mandatory for identification of patients with primary breast cancer who will benefit from primary systemic therapy with trastuzumab. The aim of the present study was to validate the application of HER2 testing with CNB specimens from primary breast cancers in terms of interobserver reproducibility and comparison with surgically resected specimens. Methods A total of 100 pairs of archival formalin-fixed paraffin-embedded CNB and surgically resected specimens of invasive breast carcinomas were cut into sections. All 100 paired sections were subjected to HER2 testing by immunohistochemistry (IHC and 27 paired sections were subjected to that by fluorescence in situ hybridization (FISH, the results being evaluated by three and two observers, respectively. Interobserver agreement levels in terms of judgment and the concordance of consensus scores between CNB samples and the corresponding surgically resected specimens were estimated as the percentage agreement and κ statistic. Results In CNB specimens, the percentage interobserver agreement of HER2 scoring by IHC was 76% (κ = 0.71 for 3 × 3 categories (0-1+ versus 2+ versus 3+ and 90% (κ = 0.80 for 2 × 2 categories (0-2+ versus 3+. These levels were close to the corresponding ones for the surgically resected specimens: 80% (κ = 0.77 for 3 × 3 categories and 92% (κ = 0.88 for 2 × 2 categories. Concordance of consensus for HER2 scores determined by IHC between CNB and the corresponding surgical specimens was 87% (κ = 0.77 for 3 × 3 categories, and 94% (κ = 0.83 for 2 × 2 categories. Among the 13 tumors showing discordance in the mean IHC scores between the CNB and surgical specimens, the results of consensus for FISH results were concordant in 11. The rate of successful FISH analysis and the FISH positivity rate in cases with a HER2 IHC score of

Agreement for HPV genotyping detection between self-collected specimens on a FTA cartridge and clinician-collected specimens

Science.gov (United States)

Guan, YaoYao; Gravitt, Patti E.; Howard, Roslyn; Eby, Yolanda J.; Wang, Shaoming; Li, Belinda; Feng, Changyan; Qiao, You-Lin; Castle, Philip E.

2016-01-01

The current method of transporting self-collected cervicovaginal specimen for HPV DNA testing relies on liquid based medium, which is challenging and expensive to transport. A novel, dry storage and transportation device, Whatman indicating FTA™ Elute Cartridge, avoids some of the pitfalls of liquid-based medium. This method has been shown to be comparable to liquid-based collection medium, but relative performance of self-collected (SC) and clinician-collected (CC) samples onto FTA cards has not been reported. The objective of this study is to compare the analytic performance of self- and clinician-collected samples onto FTA cartridges for the detection of carcinogenic HPV using Linear Array. There was a 91% agreement, 69% positive agreement, and kappa of 0.75 between the clinician-collected and self-collected specimens for detection of any carcinogenic HPV genotype. When the HPV results were categorized hierarchically according to cervical cancer risk, there was no difference in the distribution of the HPV results for the clinician- and self-collected specimens (p = 0.7). This study concludes that FTA elute cartridge is a promising method of specimen transport for cervical cancer screening programs considering using self-collected specimen and HPV testing. Larger studies with clinical endpoints are now needed to assess the clinical performance. PMID:23370404

Fuel cell end plate structure

Science.gov (United States)

Guthrie, Robin J.; Katz, Murray; Schroll, Craig R.

1991-04-23

The end plates (16) of a fuel cell stack (12) are formed of a thin membrane. Pressure plates (20) exert compressive load through insulation layers (22, 26) to the membrane. Electrical contact between the end plates (16) and electrodes (50, 58) is maintained without deleterious making and breaking of electrical contacts during thermal transients. The thin end plate (16) under compressive load will not distort with a temperature difference across its thickness. Pressure plate (20) experiences a low thermal transient because it is insulated from the cell. The impact on the end plate of any slight deflection created in the pressure plate by temperature difference is minimized by the resilient pressure pad, in the form of insulation, therebetween.

Molecular Auditing: An Evaluation of Unsuspected Tissue Specimen Misidentification.

Science.gov (United States)

Demetrick, Douglas J

2018-06-18

Context Specimen misidentification is the most significant error in laboratory medicine, potentially accounting for hundreds of millions of dollars in extra health care expenses and significant morbidity in patient populations in the United States alone. New technology allows the unequivocal documentation of specimen misidentification or contamination; however, the value of this technology currently depends on suspicion of the specimen integrity by a pathologist or other health care worker. Objective To test the hypothesis that there is a detectable incidence of unsuspected tissue specimen misidentification among cases submitted for routine surgical pathology examination. Design To test this hypothesis, we selected specimen pairs that were obtained at different times and/or different hospitals from the same patient, and compared their genotypes using standardized microsatellite markers used commonly for forensic human DNA comparison in order to identify unsuspected mismatches between the specimen pairs as a trial of "molecular auditing." We preferentially selected gastrointestinal, prostate, and skin biopsies because we estimated that these types of specimens had the greatest potential for misidentification. Results Of 972 specimen pairs, 1 showed an unexpected discordant genotype profile, indicating that 1 of the 2 specimens was misidentified. To date, we are unable to identify the etiology of the discordance. Conclusions These results demonstrate that, indeed, there is a low level of unsuspected tissue specimen misidentification, even in an environment with careful adherence to stringent quality assurance practices. This study demonstrates that molecular auditing of random, routine biopsy specimens can identify occult misidentified specimens, and may function as a useful quality indicator.

Ultrafast Laser Engraving Method to Fabricate Gravure Plate for Printed Metal-Mesh Touch Panel

Directory of Open Access Journals (Sweden)

Weiyuan Chen

2015-10-01

Full Text Available In order to engrave gravure plate with fine lines structures, conventional art used lithography with dry/wet etching. Lithography with dry/wet etching method allows to engrave lines with smooth concave shape, but its disadvantages include difficulty in controlling aspect ratio, high and uniform in large size process, substrate material limitation due to etching solution availability, and process complexity. We developed ultra-fast laser technology to directly engrave a stainless plate, a gravure plate, to be used for fabricating 23 in. metal-mesh touch panel by gravure offset printing process. The technology employs high energy pulse to ablate materials from a substrate. Because the ultra-fast laser pulse duration is shorter than the energy dissipation time between material lattices, there is no heating issue during the ablation process. Therefore, no volcano-type protrusion on the engraved line edges occurs, leading to good printing quality. After laser engraving, we then reduce surface roughness of the gravure plate using electro-polishing process. Diamond like carbon (DLC coating layer is then added onto the surface to increase scratch resistance. We show that this procedure can fabricate gravure plate for gravure offset printing process with minimum printing linewidth 10.7 μm. A 23 in. metal-mesh pattern was printed using such gravure plate and fully functional touch panel was demonstrated in this work.

Thallium toxicosis in a dog consequent to ingestion of Mycoplasma agar plates.

Science.gov (United States)

Puschner, Birgit; Basso, Marguerite M; Graham, Thomas W

2012-01-01

A 1-year-old dog ingested a mixture of blood agar and Mycoplasma agar plates. The Mycoplasma agar plates contained thallium acetate, which resulted in an estimated minimum dose of 5 mg thallium acetate/kg bodyweight. Clinical signs over the course of 2-3 weeks included vomiting, diarrhea, weight loss, alopecia, dysphonia, ataxia, paresthesia, intension tremors, megaesophagus with subsequent aspiration pneumonia, and several seizure episodes. The dog was treated with intravenous fluids and placement of a gastric feeding tube. Thallium concentrations in hair were 8.2 µg/g in samples taken on day 19, 16.4 µg/g in samples taken 3 months after exposure, 13.4 µg/g in samples taken 5 months after exposure, and nondetectable in samples taken 7 months after exposure. The blood thallium concentration was 190 µg/l on day 19 and nondetec table 3 months after exposure. Megaesophagus and dysphonia continued for 10 months after exposure. This case of thallium poisoning following ingestion of mycoplasma agar plates demonstrates that unusual sources of thallium still exist and suggests that thallium toxicosis should be included in the list of differential diagnoses in dogs presented with megaesophagus, especially if alopecia and other unexplained peripheral neuropathies are present. Hair and blood samples are useful specimens to reach an accurate diagnosis even if taken several weeks post exposure. The postexposure blood and hair thallium concentrations reported in this case are useful data for diagnosticians investigating dogs with potential thallium poisoning.

Heat insulating plates

Energy Technology Data Exchange (ETDEWEB)

Allan, J.A.F.

1976-10-28

Micro-porous insulation plates are dealt with, for example, how they are used in the insulation of heat storage devices. Since one side of such plates is exposed to a temperature of over 700/sup 0/C, a shrinkage of the glass texture of the covering can occur, which can exceed the shrinkage of the inner micro-porous material, so that cracks and splits in the high temperature side of the covering can come about. The task of the invention is to design the plate in such a way as to prevent this from happening. For this purpose the plate is provided, according to invention specifications, with flutes, waves, ribs, waffle or grid patterns and the covering is set into the recesses originating from this.

Thermal property testing technique on micro specimen

International Nuclear Information System (INIS)

Baba, Tetsuya; Kishimoto, Isao; Taketoshi, Naoyuki

2000-01-01

This study aims at establishment of further development on some testing techniques on the nuclear advanced basic research accumulated by the National Research Laboratory of Metrology for ten years. For this purpose, a technology to test heat diffusion ratio and specific heat capacity of less than 3 mm in diameter and 1 mm in thickness of micro specimen and technology to test heat diffusion ratio at micro area of less than 1 mm in area along cross section of less than 10 mm in diameter of column specimen were developed to contribute to common basic technology supporting the nuclear power field. As a result, as an element technology to test heat diffusion ratio and specific heat capacity of the micro specimen, a specimen holding technique stably to hold a micro specimen with 3 mm in diameter could be developed. And, for testing the specific heat capacity by using the laser flush differential calorimetry, a technique to hold two specimen of 5 mm in diameter at their proximities was also developed. In addition, by promoting development of thermal property data base capable of storing thermal property data obtained in this study and with excellent workability in this 1998 fiscal year a data in/out-put program with graphical user interface could be prepared. (G.K.)

Comparative study on Charpy specimen reconstitution techniques

International Nuclear Information System (INIS)

Bourdiliau, B.; Decroix, G.-M.; Averty, X.; Wident, P.; Bienvenu, Y.

2011-01-01

Highlights: → Welding processes are used to reconstitute previously tested Charpy specimens. → Stud welding is preferred for a quick installation, almost immediately operational. → Friction welding produces better quality welds, but requires a development effort. - Abstract: Reconstitution techniques are often used to allow material from previously fractured Charpy-V specimens to be reused for additional experiments. This paper presents a comparative experimental study of various reconstitution techniques and evaluates the feasibility of these methods for future use in shielded cells. The following techniques were investigated: arc stud welding, 6.0 kW CO 2 continuous wave laser welding, 4.5 kW YAG continuous wave laser welding and friction welding. Subsize Charpy specimens were reconstituted using a 400 W YAG pulsed wave laser. The best result was obtained with arc stud welding; the resilience of the reconstituted specimens and the load-displacement curves agreed well with the reference specimens, and the temperature elevation caused by the welding process was limited to the vicinity of the weld. Good results were also obtained with friction welding; this process led to the best quality welds. Laser welding seems to have affected the central part of the specimens, thus leading to different resilience values and load-displacement curves.

Design consideration of high voltage Ga2O3 vertical Schottky barrier diode with field plate

Science.gov (United States)

Choi, J.-H.; Cho, C.-H.; Cha, H.-Y.

2018-06-01

Gallium oxide (Ga2O3) based vertical Schottky barrier diodes (SBDs) were designed for high voltage switching applications. Since p-type Ga2O3 epitaxy growth or p-type ion implantation technique has not been developed yet, a field plate structure was employed in this study to maximize the breakdown voltage by suppressing the electric field at the anode edge. TCAD simulation was used for the physical analysis of Ga2O3 SBDs from which it was found that careful attention must be paid to the insulator under the field plate. Due to the extremely high breakdown field property of Ga2O3, an insulator with both high permittivity and high breakdown field must be used for the field plate formation.

Enzymatic detection of formalin-fixed museum specimens for DNA analysis and enzymatic maceration of formalin-fixed specimens

DEFF Research Database (Denmark)

Sørensen, Margrethe; Redsted Rasmussen, Arne; Simonsen, Kim Pilkjær

2016-01-01

% ethanol. The method was subsequently tested on wild-living preserved specimens and an archived specimen. The protease enzyme used was SavinaseH 16 L, Type EX from Novozymes A/S. The enzymatic screening test demands only simple laboratory equipment. The method is useful for natural history collections...

Crack-arrest behavior in SEN wide plates of low-upper-shelf base metal tested under nonisothermal conditions: WP-2 series

International Nuclear Information System (INIS)

Naus, D.J.; Keeney-Walker, J.; Bass, B.R.; Robinson, G.C. Jr.; Iskander, S.K.; Alexander, D.J.; Fields, R.J.; deWit, R.; Low, S.R.; Schwartz, C.W.

1990-08-01

The Heavy-Section Steel Technology (HSST) Program at the Oak Ridge National Laboratory under the sponsorship of the Nuclear Regulatory Commission is conducting analytical and experimental studies aimed at understanding the circumstances that would initiate the growth of an existing crack in a reactor pressure vessel (RPV) and the conditions leading to arrest of a propagating crack. Objectives of these studies are to determine (1) if the material will exhibit crack-arrest behavior when the driving force on a crack exceeds the ASME limit, (2) the relationship between K Ia and temperature, and (3) the interaction of fracture modes (arrest, stable crack growth, unstable crack growth, and tensile instability) when arrest occurs at high temperatures. In meeting these objectives, crack-arrest data are being developed over an expanded temperature range through tests involving large thermally shocked cylinders, pressurized thermally shocked vessels, and wide-plate specimens. The wide-plate specimens provide the opportunity for a significant number of data points to be obtained at relatively affordable costs. These tests are designed to provide fracture-toughness measurements approaching or above the onset of the Charpy upper-shelf regime in a rising toughness region and with an increasing driving force. This document discusses test methodology and results. 23 refs., 92 figs., 25 tabs

Fuel cell cooler-humidifier plate

Science.gov (United States)

Vitale, Nicholas G.; Jones, Daniel O.

2000-01-01

A cooler-humidifier plate for use in a proton exchange membrane (PEM) fuel cell stack assembly is provided. The cooler-humidifier plate combines functions of cooling and humidification within the fuel cell stack assembly, thereby providing a more compact structure, simpler manifolding, and reduced reject heat from the fuel cell. Coolant on the cooler side of the plate removes heat generated within the fuel cell assembly. Heat is also removed by the humidifier side of the plate for use in evaporating the humidification water. On the humidifier side of the plate, evaporating water humidifies reactant gas flowing over a moistened wick. After exiting the humidifier side of the plate, humidified reactant gas provides needed moisture to the proton exchange membranes used in the fuel cell stack assembly. The invention also provides a fuel cell plate that maximizes structural support within the fuel cell by ensuring that the ribs that form the boundaries of channels on one side of the plate have ends at locations that substantially correspond to the locations of ribs on the opposite side of the plate.

Effect of screw position on single cycle to failure in bending and torsion of a locking plate-rod construct in a synthetic feline femoral gap model.

Science.gov (United States)

Niederhäuser, Simone K; Tepic, Slobodan; Weber, Urs T

2015-05-01

To evaluate the effect of screw position on strength and stiffness of a combination locking plate-rod construct in a synthetic feline femoral gap model. 30 synthetic long-bone models derived from beechwood and balsa wood. 3 constructs (2 locking plate-rod constructs and 1 locking plate construct; 10 specimens/construct) were tested in a diaphyseal bridge plating configuration by use of 4-point bending and torsion. Variables included screw position (near the fracture gap and far from the fracture gap) and application of an intramedullary pin. Constructs were tested to failure in each loading mode to determine strength and stiffness. Failure was defined as plastic deformation of the plate or breakage of the bone model or plate. Strength, yield angle, and stiffness were compared by use of a Wilcoxon test. Placement of screws near the fracture gap did not increase bending or torsional stiffness in the locking plate-rod constructs, assuming the plate was placed on the tension side of the bone. Addition of an intramedullary pin resulted in a significant increase in bending strength of the construct. Screw positioning did not have a significant effect on any torsion variables. Results of this study suggested that, in the investigated plate-rod construct, screw insertion adjacent to the fracture lacked mechanical advantages over screw insertion at the plate ends. For surgeons attempting to minimize soft tissue dissection, the decision to make additional incisions for screw placement should be considered with even more caution.

Anatomical evidence for the anterior plate fixation of sacroiliac joint.

Science.gov (United States)

Bai, Zhibiao; Gao, Shichang; Liu, Jia; Liang, Anlin; Yu, Weihua

2018-01-01

The iatrogenic injuries to the lumbar nerves during the fixation the sacroiliac (SI) joint fractures with anterior plates were often reported. No specific method had been reported to avoid it. This study was done to find a safer way of placing the anterior plates and screws for treating the sacroiliac (SI) joint fracture and/or dislocation. The research was performed using 8 male and 7 female normal corpse pelvic specimens preserved by 10% formalin solution. Try by measuring the horizontal distance from L4, L5 nerve roots to the sacroiliac joint and perpendicular distance from L4, L5 nerve roots to the ala sacralis, the length of L4, L5 nerve roots from intervertebral foramen to the edge of true pelvis, the diameter of L4, L5 nerve roots. The angles between the sacroiliac joint and sagittal plane were measured on the CT images. The horizontal distance between the lateral side of the anterior branches of L4, L5 nerve roots and the sacroiliac joint decreased gradually from the top to the bottom. The widest distances for L4,5 were 2.1 cm (range, 1.74-2.40) and 2.7 cm (range, 2.34-3.02 cm), respectively. The smallest distances for L4, 5 were 1.2 cm (range, 0.82-1.48 cm) and 1.5 cm (range, 1.08-1.74 cm), respectively. On CT images, the angle between the sacroiliac joint and sagittal plane was about 30°. If we use two anterior plates to fix the sacroiliac joint, It is recommended to place one plate on the superior one third part of the joint, with exposing medially no more than 2.5 cm and the other in the middle one third part of the joint, with elevating periosteum medially no more than 1.5 cm. The screws in the sacrum are advised to incline medially about 30° directing to the true pelvis. Copyright © 2017. Published by Elsevier B.V.

Closeout of JOYO-1 Specimen Fabrication Efforts

International Nuclear Information System (INIS)

ME Petrichek; JL Bump; RF Luther

2005-01-01

Fabrication was well under way for the JOYO biaxial creep and tensile specimens when the NR Space program was canceled. Tubes of FS-85, ASTAR-811C, and T-111 for biaxial creep specimens had been drawn at True Tube (Paso Robles, CA), while tubes of Mo-47.5 Re were being drawn at Rhenium Alloys (Cleveland, OH). The Mo-47.5 Re tubes are now approximately 95% complete. Their fabrication and the quantities produced will be documented at a later date. End cap material for FS-85, ASTAR-811C, and T-111 had been swaged at Pittsburgh Materials Technology, Inc. (PMTI) (Large, PA) and machined at Vangura (Clairton, PA). Cutting of tubes, pickling, annealing, and laser engraving were in process at PMTI. Several biaxial creep specimen sets of FS-85, ASTAR-811C, and T-111 had already been sent to Pacific Northwest National Laboratory (PNNL) for weld development. In addition, tensile specimens of FS-85, ASTAR-811C, T-111, and Mo-47.5 Re had been machined at Kin-Tech (North Huntington, PA). Actual machining of the other specimen types had not been initiated. Flowcharts 1-3 detail the major processing steps each piece of material has experienced. A more detailed description of processing will be provided in a separate document [B-MT(SRME)-51]. Table 1 lists the in-process materials and finished specimens. Also included are current metallurgical condition of these materials and specimens. The available chemical analyses for these alloys at various points in the process are provided in Table 2

Theroretical modelling of the plate-tubes coupling in the hydroelasticity of the perforated plates

International Nuclear Information System (INIS)

Dzhupanov, V.A.; Manoach, E.S.

1983-01-01

In the previous investigations on the perforated plate hydroelasticity the problem of the plates-tubes-liquid interaction in the process of the general structural vibration is stated. But the interaction of the vibrating plates with the tubes, passing through them, is taken into account considering the tubes only as absolutely rigid supports. This is one of the possible technical realizations. In the present article the case when the tubes are taking part in the plate motion (vibration) is studied. Two circular perforated plates are supported by the absolutely rigid wall of the modelled roundcircular reactor barrel. The distance between the plates is given. They are connected by tubes, passing through, and clamped into the perforation holes. The plates and the tubes are made by any elastic HOOKIAN material. The volume between the two plates and outwardly to the tubes, but intrinsically of the barrel is filled by ideal, compressible and heavy liquid. Evidently the liquid volume is multiconnected one. The free vibration of the whole system is considered with the purposes: i) to give a theoretical model of the plates-tubes-liquid interaction including governing equations and boundary conditions; ii) to trace the solution of the eigen-value problem for the modelled structure; iii) to underline the engineering sides of the modelling process. (orig./GL)

Wettability measurements of irregular shapes with Wilhelmy plate method

Science.gov (United States)

Park, Jaehyung; Pasaogullari, Ugur; Bonville, Leonard

2018-01-01

One of the most accurate methods for measuring the dynamic contact angle of liquids on solid surfaces is the Wilhelmy plate method. This method generally requires the use of rectangular samples having a constant perimeter in the liquid during advancing and receding cycles. A new formulation based on the Wilhelmy force balance equation to determine the contact angle for plate samples with irregular shapes has been developed. This method employs a profile plot obtained from an optical image to determine the perimeter (i.e. wetted length) of the sample as a function of the immersion depth. The raw force data measured by the force tensiometer is manipulated using the profile plot and the Wilhelmy equation to determine the wetting force and consequently advancing and the receding contact angle. This method is verified with both triangular and irregular PTFE samples in water, and measured contact angles are in good agreement with results from conventional regular shaped samples with a constant perimeter.

Modeling of parallel-plate regenerators with non-uniform plate distributions

DEFF Research Database (Denmark)

Jensen, Jesper Buch; Engelbrecht, Kurt; Bahl, Christian Robert Haffenden

2010-01-01

plate spacing distributions are presented in order to understand the impact of spacing non-uniformity. Simulations of more realistic distributions where the plate spacings follow normal distributions are then discussed in order to describe the deviation of the performance of a regenerator relative...

Highly conductive composites for fuel cell flow field plates and bipolar plates

Science.gov (United States)

Jang, Bor Z; Zhamu, Aruna; Song, Lulu

2014-10-21

This invention provides a fuel cell flow field plate or bipolar plate having flow channels on faces of the plate, comprising an electrically conductive polymer composite. The composite is composed of (A) at least 50% by weight of a conductive filler, comprising at least 5% by weight reinforcement fibers, expanded graphite platelets, graphitic nano-fibers, and/or carbon nano-tubes; (B) polymer matrix material at 1 to 49.9% by weight; and (C) a polymer binder at 0.1 to 10% by weight; wherein the sum of the conductive filler weight %, polymer matrix weight % and polymer binder weight % equals 100% and the bulk electrical conductivity of the flow field or bipolar plate is at least 100 S/cm. The invention also provides a continuous process for cost-effective mass production of the conductive composite-based flow field or bipolar plate.

Neutron stress measurement using image plate and the cos α method

International Nuclear Information System (INIS)

Sasaki, Toshihiko; Hirose, Yukio; Minakawa, Nobuaki; Morii, Yukio

2004-01-01

A new type of the neutron stress measurement method, in which the stress is determined by the cos α method, was studied. A neutron image plate was used in this study for detecting the diffraction image. Steel specimens of 5 mm thickness were used for the tensile stress test. The stresses obtain from the experiment showed one-to-one ratio with respect to the applied stresses, though the misfit stress of about 400 MPa was also observed in the result. A simple correction technique for calibrating raw data was proposed to obtain the true stress. A simulation study was carried out to check the experimental result on the peak positions in the diffraction ring and the stress calculation by the cos α method. (author)

Ni-based amorphous alloy-coating for bipolar plate of PEM fuel cell by electrochemical plating

International Nuclear Information System (INIS)

Yamaura, S; Kim, S C; Inoue, A

2013-01-01

In this study, the Ni-Cr-P amorphous alloy-coated bipolar plates were produced by electro-plating on the Cu base plates with a flow field. The power generation tests of a single fuel cell with those Ni-Cr-P bipolar plates were conducted at 353 K. It was found that the single fuel cell with those Ni-Cr-P bipolar plates showed excellent I-V performance as well as that with the carbon graphite bipolar plates. It was also found that the single cell with those Ni-Cr-P bipolar plates showed better I-V performance than that with the Ni-P amorphous alloy-coated bipolar plates. Furthermore, the long-time operation test was conducted for 440 h with those Ni-Cr-P bipolar plates at the constant current density of 200 mA·cm −2 . As a result, it was found that the cell voltage gradually decreased at the beginning of the measurement before 300 h and then the voltage was kept constant after 300 h.

Simultaneous specimen and stage cleaning device for analytical electron microscope

Science.gov (United States)

Zaluzec, Nestor J.

1996-01-01

An improved method and apparatus are provided for cleaning both a specimen stage, a specimen and an interior of an analytical electron microscope (AEM). The apparatus for cleaning a specimen stage and specimen comprising a plasma chamber for containing a gas plasma and an air lock coupled to the plasma chamber for permitting passage of the specimen stage and specimen into the plasma chamber and maintaining an airtight chamber. The specimen stage and specimen are subjected to a reactive plasma gas that is either DC or RF excited. The apparatus can be mounted on the analytical electron microscope (AEM) for cleaning the interior of the microscope.

Three-dimensional inverse transient heat transfer analysis of thick functionally graded plates

Energy Technology Data Exchange (ETDEWEB)

Haghighi, M.R. Golbahar; Malekzadeh, P. [Department of Mechanical Engineering, School of Engineering, Persian Gulf University, Bushehr 75168 (Iran); Eghtesad, M. [Department of Mechanical Engineering, School of Engineering, Shiraz University, Shiraz 71348-51154 (Iran); Necsulescu, D.S. [Department of Mechanical Engineering, Faculty of Engineering, University of Ottawa, Ottawa, Ontario (Canada)

2009-03-15

In this paper, a three-dimensional transient inverse heat conduction (IHC) procedure is presented to estimate the unknown boundary heat flux of thick functionally graded (FG) plates. For this purpose, the conjugate gradient method (CGM) in conjunction with adjoint problem is used. A recently developed three-dimensional efficient hybrid method is employed to solve variable-coefficient initial-boundary-value differential equations of direct problem as a part of the inverse solution. The accuracy of the inverse analysis is examined by simulating the exact and noisy data for problems with different types of boundary conditions and material properties. In addition to rectangular domain, skew plates are considered. The results obtained show good accuracy for the estimation of boundary heat fluxes. (author)

Finite element analysis of actively controlled smart plate with patched actuators and sensors

Directory of Open Access Journals (Sweden)

M. Yaqoob Yasin

Full Text Available The active vibration control of smart plate equipped with patched piezoelectric sensors and actuators is presented in this study. An equivalent single layer third order shear deformation theory is employed to model the kinematics of the plate and to obtain the shear strains. The governing equations of motion are derived using extended Hamilton's principle. Linear variation of electric potential across the piezoelectric layers in thickness direction is considered. The electrical variable is discretized by Lagrange interpolation function considering two-noded line element. Undamped natural frequencies and the corresponding mode shapes are obtained by solving the eigen value problem with and without electromechanical coupling. The finite element model in nodal variables are transformed into modal model and then recast into state space. The dynamic model is reduced for further analysis using Hankel norm for designing the controller. The optimal control technique is used to control the vibration of the plate.

Free Vibration Analysis of Composite Plates via Refined Theories Accounting for Uncertainties

Directory of Open Access Journals (Sweden)

G. Giunta

2011-01-01

Full Text Available The free vibration analysis of composite thin and relatively thick plates accounting for uncertainty is addressed in this work. Classical and refined two-dimensional models derived via Carrera's Unified Formulation (CUF are considered. Material properties and geometrical parameters are supposed to be random. The fundamental frequency related to the first bending eigenmode is stochastically described in terms of the mean value, the standard deviation, the related confidence intervals and the cumulative distribution function. The Monte Carlo Method is employed to account for uncertainty. Cross-ply, simply supported, orthotropic plates are accounted for. Symmetric and anti-symmetric lay-ups are investigated. Displacements based and mixed two-dimensional theories are adopted. Equivalent single layer and layer wise approaches are considered. A Navier type solution is assumed. The conducted analyses have shown that for the considered cases, the fundamental natural frequency is not very sensitive to the uncertainty in the material parameters, while uncertainty in the geometrical parameters should be accounted for. In the case of thin plates, all the considered models yield statistically matching results. For relatively thick plates, the difference in the mean value of the natural frequency is due to the different number of degrees of freedom in the model.

Agreement for HPV genotyping detection between self-collected specimens on a FTA cartridge and clinician-collected specimens.

Science.gov (United States)

Guan, Yaoyao; Gravitt, Patti E; Howard, Roslyn; Eby, Yolanda J; Wang, Shaoming; Li, Belinda; Feng, Changyan; Qiao, You-Lin; Castle, Philip E

2013-04-01

The current method of transporting self-collected cervicovaginal specimen for HPV DNA testing relies on liquid based medium, which is challenging and expensive to transport. A novel, dry storage and transportation device, Whatman indicating FTA™ Elute Cartridge, avoids some of the pitfalls of liquid-based medium. This method has been shown to be comparable to liquid-based collection medium, but relative performance of self-collected (SC) and clinician-collected (CC) samples onto FTA cards has not been reported. The objective of this study is to compare the analytic performance of self- and clinician-collected samples onto FTA cartridges for the detection of carcinogenic HPV using Linear Array. There was a 91% agreement, 69% positive agreement, and kappa of 0.75 between the clinician-collected and self-collected specimens for detection of any carcinogenic HPV genotype. When the HPV results were categorized hierarchically according to cervical cancer risk, there was no difference in the distribution of the HPV results for the clinician- and self-collected specimens (p=0.7). This study concludes that FTA elute cartridge is a promising method of specimen transport for cervical cancer screening programs considering using self-collected specimen and HPV testing. Larger studies with clinical endpoints are now needed to assess the clinical performance. Copyright © 2012 Elsevier B.V. All rights reserved.

Open Channel Natural Convection Heat Transfer on a Vertical Finned Plate

International Nuclear Information System (INIS)

Park, Joo Hyun; Heo, Jeong Hwan; Chung, Bum Jin

2013-01-01

The natural convection heat transfer of vertical plate fin was investigated experimentally. Heat transfer systems were replaced by mass-transfer systems, based on the analogy concept. The experimental results lie within the predictions of the existing heat transfer correlations of plate-fin for the natural convections. An overlapped thermal boundary layers caused increasing heat transfer, and an overlapped momentum boundary layers caused decreasing heat transfer. As the fin height increases, heat transfer was enhanced due to increased inflow from the open side of the fin spacing. When fin spacing and fin height are large, heat transfer was unaffected by the fin spacing and fin height. Passive cooling by natural convection becomes more and more important for the nuclear systems as the station black out really happened at the Fukushima NPPs. In the RCCS (Reactor Cavity Cooling System) of a VHTR (Very High Temperature Reactor), natural convection cooling through duct system is adopted. In response to the stack failure event, extra cooling capacity adopting the fin array has to be investigated. The finned plate increases the surface area and the heat transfer increases. However, the plate of fin arrays may increase the pressure drop and the heat transfer decreases. Therefore, in order to enhance the passive cooling with fin arrays, the parameters for the fin arrays should be optimized. According to Welling and Wooldridge, a natural convection on vertical plate fin is function of Gr, Pr, L, t, S, and H. The present work investigated the natural convection heat transfer of a vertical finned plate with varying the fin height and the fin spacing. In order achieve high Rayleigh numbers, an electroplating system was employed and the mass transfer rates were measured using a copper sulfate electroplating system based on the analogy concept

Ricochet of a tungsten heavy alloy long-rod projectile from deformable steel plates

International Nuclear Information System (INIS)

Lee, Woong; Lee, Heon-Joo; Shin, Hyunho

2002-01-01

Ricochet of a tungsten heavy alloy long-rod projectile from oblique steel plates with a finite thickness was investigated numerically using a full three-dimensional explicit finite element method. Three distinctive regimes resulting from oblique impact depending on the obliquity, namely simple ricochet, critical ricochet and target perforation, were investigated in detail. Critical ricochet angles were calculated for various impact velocities and strengths of the target plates. It was predicted that critical ricochet angle increases with decreasing impact velocities and that higher ricochet angles were expected if higher strength target materials are employed. Numerical predictions were compared with existing two-dimensional analytical models. Experiments were also carried out and the results supported the predictions of the numerical analysis

A cylindrical specimen holder for electron cryo-tomography

International Nuclear Information System (INIS)

Palmer, Colin M.; Löwe, Jan

2014-01-01

The use of slab-like flat specimens for electron cryo-tomography restricts the range of viewing angles that can be used. This leads to the “missing wedge” problem, which causes artefacts and anisotropic resolution in reconstructed tomograms. Cylindrical specimens provide a way to eliminate the problem, since they allow imaging from a full range of viewing angles around the tilt axis. Such specimens have been used before for tomography of radiation-insensitive samples at room temperature, but never for frozen-hydrated specimens. Here, we demonstrate the use of thin-walled carbon tubes as specimen holders, allowing the preparation of cylindrical frozen-hydrated samples of ribosomes, liposomes and whole bacterial cells. Images acquired from these cylinders have equal quality at all viewing angles, and the accessible tilt range is restricted only by the physical limits of the microscope. Tomographic reconstructions of these specimens demonstrate that the effects of the missing wedge are substantially reduced, and could be completely eliminated if a full tilt range was used. The overall quality of these tomograms is still lower than that obtained by existing methods, but improvements are likely in future. - Highlights: • The missing wedge is a serious problem for electron cryo-tomography. • Cylindrical specimens allow the missing wedge to be eliminated. • Carbon nanopipettes can be used as cylindrical holders for tomography of frozen-hydrated specimens. • Cryo-tomography of cylindrical biological samples demonstrates a reduction of deleterious effects associated with the missing wedge

Create Your Plate

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Full Text Available ... foods you want, but changes the portion sizes so you are getting larger portions of non-starchy ... plate. Then on one side, cut it again so you will have three sections on your plate. ...

49 CFR Appendix B to Part 40 - DOT Drug Testing Semi-Annual Laboratory Report to Employers

Science.gov (United States)

2010-10-01

... TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Pt. 40, App. B Appendix B to Part 40—DOT Drug Testing.... Specimen Results Reported (total number) By Test Reason (a) Pre-employment (number) (b) Post-Accident...

Elastic stability of thick auxetic plates

International Nuclear Information System (INIS)

Lim, Teik-Cheng

2014-01-01

Auxetic materials and structures exhibit a negative Poisson’s ratio while thick plates encounter shear deformation, which is not accounted for in classical plate theory. This paper investigates the effect of a negative Poisson’s ratio on thick plates that are subjected to buckling loads, taking into consideration the shear deformation using Mindlin plate theory. Using a highly accurate shear correction factor that allows for the effect of Poisson’s ratio, the elastic stability of circular and square plates are evaluated in terms of dimensionless parameters, namely the Mindlin-to-Kirchhoff critical buckling load ratio and Mindlin critical buckling load factors. Results for thick square plates reveal that both parameters increase as the Poisson’s ratio becomes more negative. In the case of thick circular plates, the Mindlin-to-Kirchhoff critical buckling load ratios and the Mindlin critical buckling load factors increase and decrease, respectively, as the Poisson’s ratio becomes more negative. The results obtained herein show that thick auxetic plates behave as thin conventional plates, and therefore suggest that the classical plate theory can be used to evaluate the elastic stability of thick plates if the Poisson’s ratio of the plate material is sufficiently negative. The results also suggest that materials with highly negative Poisson’s ratios are recommended for square plates, but not circular plates, that are subjected to buckling loads. (paper)

Quantification of thickness loss in a liquid-loaded plate using ultrasonic guided wave tomography

Science.gov (United States)

Rao, Jing; Ratassepp, Madis; Fan, Zheng

2017-12-01

Ultrasonic guided wave tomography (GWT) provides an attractive solution to map thickness changes from remote locations. It is based on the velocity-to-thickness mapping employing the dispersive characteristics of selected guided modes. This study extends the application of GWT on a liquid-loaded plate. It is a more challenging case than the application on a free plate, due to energy of the guided waves leaking into the liquid. In order to ensure the accuracy of thickness reconstruction, advanced forward models are developed to consider attenuation effects using complex velocities. The reconstruction of the thickness map is based on the frequency-domain full waveform inversion (FWI) method, and its accuracy is discussed using different frequencies and defect dimensions. Validation experiments are carried out on a water-loaded plate with an irregularly shaped defect using S0 guided waves, showing excellent performance of the reconstruction algorithm.

An accurate higher order displacement model with shear and normal deformations effects for functionally graded plates

Energy Technology Data Exchange (ETDEWEB)

Jha, D.K., E-mail: dkjha@barc.gov.in [Civil Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Kant, Tarun [Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India); Srinivas, K. [Civil Engineering Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Singh, R.K. [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-12-15

Highlights: • We model through-thickness variation of material properties in functionally graded (FG) plates. • Effect of material grading index on deformations, stresses and natural frequency of FG plates is studied. • Effect of higher order terms in displacement models is studied for plate statics. • The benchmark solutions for the static analysis and free vibration of thick FG plates are presented. -- Abstract: Functionally graded materials (FGMs) are the potential candidates under consideration for designing the first wall of fusion reactors with a view to make best use of potential properties of available materials under severe thermo-mechanical loading conditions. A higher order shear and normal deformations plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply (diaphragm) supported plates. Although FGMs are highly heterogeneous in nature, they are generally idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed here to vary through thickness of plate in a continuous manner. Young's modulii and material densities are considered to be varying continuously in thickness direction according to volume fraction of constituents which are mathematically modeled here as exponential and power law functions. The effects of variation of material properties in terms of material gradation index on deformations, stresses and natural frequency of FG plates are investigated. The accuracy of present numerical solutions has been established with respect to exact three-dimensional (3D) elasticity solutions and the other models’ solutions available in literature.

Energy transfer between a passing vortex ring and a flexible plate in an ideal quiescent fluid

Energy Technology Data Exchange (ETDEWEB)

Hu, JiaCheng; Peterson, Sean D., E-mail: peterson@mme.uwaterloo.ca [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Porfiri, Maurizio [Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, New York 11201 (United States)

2015-09-21

Recent advancements in highly deformable smart materials have lead to increasing interest in small-scale energy harvesting research for powering low consumption electronic devices. One such recent experimental study by Goushcha et al. explored energy harvesting from a passing vortex ring by a cantilevered smart material plate oriented parallel to and offset from the path of the ring in an otherwise quiescent fluid. The present study focuses on modeling this experimental study using potential flow to facilitate optimization of the energy extraction from the passing ring to raise the energy harvesting potential of the device. The problem is modeled in two-dimensions with the vortex ring represented as a pair of counter-rotating free vortices. Vortex pair parameters are determined to match the convection speed of the ring in the experiments, as well as the imposed pressure loading on the plate. The plate is approximated as a Kirchhoff-Love plate and represented as a finite length vortex sheet in the fluid domain. The analytical model matches experimental measurements, including the tip displacement, the integrated force along the entire plate length as a function of vortex ring position, and the pressure along the plate. The potential flow solution is employed in a parametric study of the governing dimensionless parameters in an effort to guide the selection of plate properties for optimal energy harvesting performance. Results of the study indicate an optimal set of plate properties for a given vortex ring configuration, in which the time-scale of vortex advection matches that of the plate vibration.

An accurate higher order displacement model with shear and normal deformations effects for functionally graded plates

International Nuclear Information System (INIS)

Jha, D.K.; Kant, Tarun; Srinivas, K.; Singh, R.K.

2013-01-01

Highlights: • We model through-thickness variation of material properties in functionally graded (FG) plates. • Effect of material grading index on deformations, stresses and natural frequency of FG plates is studied. • Effect of higher order terms in displacement models is studied for plate statics. • The benchmark solutions for the static analysis and free vibration of thick FG plates are presented. -- Abstract: Functionally graded materials (FGMs) are the potential candidates under consideration for designing the first wall of fusion reactors with a view to make best use of potential properties of available materials under severe thermo-mechanical loading conditions. A higher order shear and normal deformations plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply (diaphragm) supported plates. Although FGMs are highly heterogeneous in nature, they are generally idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed here to vary through thickness of plate in a continuous manner. Young's modulii and material densities are considered to be varying continuously in thickness direction according to volume fraction of constituents which are mathematically modeled here as exponential and power law functions. The effects of variation of material properties in terms of material gradation index on deformations, stresses and natural frequency of FG plates are investigated. The accuracy of present numerical solutions has been established with respect to exact three-dimensional (3D) elasticity solutions and the other models’ solutions available in literature

Replacement/Refurbishment of JSC/NASA POD Specimens

Science.gov (United States)

Castner, Willard L.

2010-01-01

The NASA Special NDE certification process requires demonstration of NDE capability by test per NASA-STD-5009. This test is performed with fatigue cracked specimens containing very small cracks. The certification test results are usually based on binomial statistics and must meet a 90/95 Probability of Detection (POD). The assumption is that fatigue cracks are tightly closed, difficult to detect, and inspectors and processes passing such a test are well qualified for inspecting NASA fracture critical hardware. The JSC NDE laboratory has what may be the largest inventory that exists of such fatigue cracked NDE demonstration specimens. These specimens were produced by the hundreds in the late 1980s and early 1990s. None have been produced since that time and the condition and usability of the specimens are questionable.

Neutron imaging plates

International Nuclear Information System (INIS)

Niimura, Nobuo

1995-01-01

Imaging plates have been used in the field of medical diagnosis since long ago, but their usefulness was verified as the two-dimensional detector for analyzing the X-ray crystalline structure of high bio molecules like protein, and they have contributed to the remarkable progress in this field. The great contribution is due to the excellent features, such as the detection efficiency of about 100%, the positional resolution smaller than 0.2 mm, the dynamic range of five digits, and the area of several hundreds mm square. The neutron imaging plates have not yet obtained the sufficient results. It was planned to construct the neutron diffractometer for biological matters, and to put imaging plate neutron detectors (IP-ND) to practical use as the detector. The research on the development of IP-NDs was carried out, and the IPp-NDs having the performance comparable with that for X-ray were able to be produced. Imaging plates are the integral type two-dimensional radiation detector using photostimulated luminescence matters, and their principle is explained. As to neutron imaging plates, the converter, neutron detection efficiency and the flight of secondary particles in photo-stimulated luminescence matters are described. As for the present state of development of neutron imaging plates, the IP-NDs made for trial, the dynamic range, the positional resolution, the detection efficiency and the kinds of converters, and the application of IP-NDs are reported. (K.I.)

Performance of Retrofitted Self-Compacting Concrete-Filled Steel Tube Beams Using External Steel Plates

Directory of Open Access Journals (Sweden)

Ahmed A. M. AL-Shaar

2018-01-01

Full Text Available Self-compacting concrete-filled steel tube (SCCFST beams, similar to other structural members, necessitate retrofitting for many causes. However, research on SCCFST beams externally retrofitted by bolted steel plates has seldom been explored in the literature. This paper aims at experimentally investigating the retrofitting performance of square self-compacting concrete-filled steel tube (SCCFST beams using bolted steel plates with three different retrofitting schemes including varied configurations and two different steel plate lengths under flexure. A total of 18 specimens which consist of 12 retrofitted SCCFST beams, three unretrofitted (control SCCFST beams, and three hollow steel tubes were used. The flexural behaviour of the retrofitted SCCFST beams was examined regarding flexural strength, failure modes, and moment versus deflection curves, energy absorption, and ductility. Experimental results revealed that the implemented retrofitting schemes efficiently improve the moment carrying capacity and stiffness of the retrofitted SCCFST beams compared to the control beams. The increment in flexural strength ranged from 1% to 46%. Furthermore, the adopted retrofitting schemes were able to restore the energy absorption and ductility of the damaged beams in the range of 35% to 75% of the original beam ductility. Furthermore, a theoretical model was suggested to predict the moment capacity of the retrofitted SCCFST beams. The theoretical model results were in good agreement with the test results.

The influence of specimen size on creep crack growth rate in cross-weld CT specimens cut out from a welded component

International Nuclear Information System (INIS)

Andersson, Peder; Segle, Peter; Samuelson, Lars Aa.

1999-04-01

A 3D finite element study of creep crack growth in cross-weld CT specimens with material properties of 2.25Cr1Mo at 550 deg C is carried out, where large strain and displacement theory is used. The creep crack growth rate is calculated using a creep ductility based damage model, in which the creep strain rate perpendicular to the crack plane ahead of the crack tip is integrated, considering the multiaxial stress state. The influence of specimen size on creep crack growth rate under constant load is given special attention, but the possibility to transfer results from cross-weld CT specimens to welded high temperature components is also investigated. The creep crack growth rate of a crack in a circumferentially welded pipe is compared with the creep crack growth rate of cross-weld CT specimens of three different sizes, cut out from the pipe. Although the constraint ahead of the crack tip is higher for a larger CT specimen, the creep crack growth rate is higher for a smaller specimen than for a larger one if they are loaded to attain the same stress intensity factor. If the specimens are loaded to the same C* value, however, a more complicated pattern occurs; depending on the material properties of the weldment constituents, the CT specimen with the intermediate size will either yield the highest or the lowest creep crack growth rate

Studies on the temperature distribution of steel plates with different paints under solar radiation

International Nuclear Information System (INIS)

Liu, Hongbo; Chen, Zhihua; Chen, Binbin; Xiao, Xiao; Wang, Xiaodun

2014-01-01

Thermal effects on steel structures exposed to solar radiation are significant and complicated. Furthermore, the solar radiation absorption coefficient of steel surface with different paintings is the main factor affecting the non-uniform temperature of spatial structures under solar radiation. In this paper, nearly two hundreds steel specimens with different paintings were designed and measured to obtain their solar radiation absorption coefficients using spectrophotometer. Based on the test results, the effect of surface color, painting type, painting thickness on the solar radiation absorption coefficient was analyzed. The actual temperatures under solar radiation for all specimens were also measured in summer not only to verify the absorption coefficient but also provide insight for the temperature distribution of steel structures with different paintings. A numerical simulation and simplified formula were also conducted and verified by test, in order to study the temperature distribution of steel plates with different paints under solar radiation. The results have given an important reference in the future research of thermal effect of steel structures exposed to solar radiation. - Highlights: • Solar radiation absorptions for steel with different paintings were measured. • The temperatures of all specimens under solar radiation were measured. • The effect of color, thickness and painting type on solar absorption was analyzed. • A numerical analysis was conducted and verified by test data. • A simplified formula was deduced and verified by test data

A layer-wise MITC9 finite element for the free-vibration analysis of plates with piezo-patches

Directory of Open Access Journals (Sweden)

Maria Cinefra

2015-04-01

Full Text Available The present article considers the free-vibration analysis of plate structures with piezoelectric patches by means of a plate finite element with variable through-the-thickness layer-wise kinematic. The refined models used are derived from Carrera’s Unified Formulation (CUF and they permit the vibration modes along the thickness to be accurately described. The finite-element method is employed and the plate element implemented has nine nodes, and the mixed interpolation of tensorial component (MITC method is used to contrast the membrane and shear locking phenomenon. The related governing equations are derived from the principle of virtual displacement, extended to the analysis of electromechanical problems. An isotropic plate with piezoelectric patches is analyzed, with clamped-free boundary conditions and subjected to open- and short-circuit configurations. The results, obtained with different theories, are compared with the higher-order type solutions given in the literature. The conclusion is reached that the plate element based on the CUF is more suitable and efficient compared to the classical models in the study of multilayered structures embedding piezo-patches.

Anisotropic elastic plates

CERN Document Server

Hwu, Chyanbin

2010-01-01

As structural elements, anisotropic elastic plates find wide applications in modern technology. The plates here are considered to be subjected to not only in plane load but also transverse load. In other words, both plane and plate bending problems as well as the stretching-bending coupling problems are all explained in this book. In addition to the introduction of the theory of anisotropic elasticity, several important subjects have are discussed in this book such as interfaces, cracks, holes, inclusions, contact problems, piezoelectric materials, thermoelastic problems and boundary element a

Buckling analysis for axially compressed flat plates, structural sections, and stiffened plates reinforced with laminated composites

Science.gov (United States)

Viswanathan, A. V.; Soong, T.; Miller, R. E., Jr.

1971-01-01

A classical buckling analysis is developed for stiffened, flat plates composed of a series of linked plate and beam elements. Plates are idealized as multilayered orthotropic elements. Structural beads and lips are idealized as beams. The loaded edges of the stiffened plate are simply-supported and the conditions at the unloaded edges can be prescribed arbitrarily. The plate and beam elements are matched along their common junctions for displacement continuity and force equilibrium in an exact manner. Offsets between elements are considered in the analysis. Buckling under uniaxial compressive load for plates, sections, and stiffened plates is investigated. Buckling loads are the lowest of all possible general and local failure modes, and the mode shape is used to determine whether buckling is a local or general instability. Numerical correlations with existing analysis and test data for plates, sections, and stiffened plates including boron-reinforced structures are discussed. In general correlations are reasonably good.

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BAO Plate Archive Project

Science.gov (United States)

Mickaelian, A. M.; Gigoyan, K. S.; Gyulzadyan, M. V.; Paronyan, G. M.; Abrahamyan, H. V.; Andreasyan, H. R.; Azatyan, N. M.; Kostandyan, G. R.; Samsonyan, A. L.; Mikayelyan, G. A.; Farmanyan, S. V.; Harutyunyan, V. L.

2017-12-01

We present the Byurakan Astrophysical Observatory (BAO) Plate Archive Project that is aimed at digitization, extraction and analysis of archival data and building an electronic database and interactive sky map. BAO Plate Archive consists of 37,500 photographic plates and films, obtained with 2.6m telescope, 1m and 0.5m Schmidt telescopes and other smaller ones during 1947-1991. The famous Markarian Survey (or the First Byurakan Survey, FBS) 2000 plates were digitized in 2002-2005 and the Digitized FBS (DFBS, www.aras.am/Dfbs/dfbs.html) was created. New science projects have been conducted based on this low-dispersion spectroscopic material. Several other smaller digitization projects have been carried out as well, such as part of Second Byurakan Survey (SBS) plates, photographic chain plates in Coma, where the blazar ON 231 is located and 2.6m film spectra of FBS Blue Stellar Objects. However, most of the plates and films are not digitized. In 2015, we have started a project on the whole BAO Plate Archive digitization, creation of electronic database and its scientific usage. Armenian Virtual Observatory (ArVO, www.aras.am/Arvo/arvo.htm) database will accommodate all new data. The project runs in collaboration with the Armenian Institute of Informatics and Automation Problems (IIAP) and will continues during 4 years in 2015-2018. The final result will be an Electronic Database and online Interactive Sky map to be used for further research projects. ArVO will provide all standards and tools for efficient usage of the scientific output and its integration in international databases.