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Sample records for charpy impact test

  1. Charpy Impact Test on Polymeric Molded Parts

    OpenAIRE

    Alexandra Raicu

    2012-01-01

    The paper presents the Charpy impact tests on the AcrylonitrileButadiene-Styrene (ABS) polymeric material parts. The Charpy impact test, also known as the Charpy V-notch test, is a standardized strain rate test which determines the amount of energy absorbed by a material during fracture. This is a typical method described in ASTM Standard D 6110. We use for testing an Instron - Dynatup equipment which have a fully integrated hardware and software package that let us capture ...

  2. Charpy Impact Test on Polymeric Molded Parts

    Directory of Open Access Journals (Sweden)

    Alexandra Raicu

    2012-09-01

    Full Text Available The paper presents the Charpy impact tests on the AcrylonitrileButadiene-Styrene (ABS polymeric material parts. The Charpy impact test, also known as the Charpy V-notch test, is a standardized strain rate test which determines the amount of energy absorbed by a material during fracture. This is a typical method described in ASTM Standard D 6110. We use for testing an Instron - Dynatup equipment which have a fully integrated hardware and software package that let us capture load information at very high speed from the impact tests.

  3. Microstructural characterization of Charpy-impact-tested nanostructured bainite

    International Nuclear Information System (INIS)

    In this work, a possible cause of the extraordinary low impact toughness of nanostructured bainite has been investigated. The microstructure of nanostructured bainite consisted chiefly of carbide-free bainitic ferrite with retained austenite films. X-ray diffractometry (XRD) measurement indicated that no retained austenite existed in the fractured surface of the Charpy-impact-tested specimens. Fractographs showed that cracks propagated mainly along bainitic ferrite platelet boundaries. The change in microstructure after impact loading was verified by transmission electron microscopy (TEM) observations, confirming that retained austenite was completely transformed to strain-induced martensite during the Charpy impact test. However, the zone affected by strained-induced martensite was found to be extremely shallow, only to a depth of several micrometers from the fracture surface. It is appropriately concluded that upon impact, as the crack forms and propagates, strain-induced martensitic transformation immediately occurs ahead of the advancing crack tip. The successive martensitic transformation profoundly facilitates the crack propagation, resulting in the extremely low impact toughness of nanostructured bainite. Retained austenite, in contrast to its well-known beneficial role, has a deteriorating effect on toughness during the course of Charpy impact. - Highlights: • The microstructure of nanostructured bainite consisted of nano-sized bainitic ferrite subunits with retained austenite films. • Special sample preparations for SEM, XRD and TEM were made, and the strain-affected structures have been explored. • Retained austenite films were found to transform into martensite after impact loading, as evidenced by XRD and TEM results. • The zone of strain-induced martensite was found to extend to only several micrometers from the fracture surface. • The poor Charpy impact toughness is associated with the fracture of martensite at a high strain rate during

  4. Microstructural characterization of Charpy-impact-tested nanostructured bainite

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Y.T.; Chang, H.T.; Huang, B.M. [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC (China); Huang, C.Y. [Iron and Steel R& D Department, China Steel Corporation, Kaohsiung, Taiwan, ROC (China); Yang, J.R., E-mail: jryang@ntu.edu.tw [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan, ROC (China)

    2015-09-15

    In this work, a possible cause of the extraordinary low impact toughness of nanostructured bainite has been investigated. The microstructure of nanostructured bainite consisted chiefly of carbide-free bainitic ferrite with retained austenite films. X-ray diffractometry (XRD) measurement indicated that no retained austenite existed in the fractured surface of the Charpy-impact-tested specimens. Fractographs showed that cracks propagated mainly along bainitic ferrite platelet boundaries. The change in microstructure after impact loading was verified by transmission electron microscopy (TEM) observations, confirming that retained austenite was completely transformed to strain-induced martensite during the Charpy impact test. However, the zone affected by strained-induced martensite was found to be extremely shallow, only to a depth of several micrometers from the fracture surface. It is appropriately concluded that upon impact, as the crack forms and propagates, strain-induced martensitic transformation immediately occurs ahead of the advancing crack tip. The successive martensitic transformation profoundly facilitates the crack propagation, resulting in the extremely low impact toughness of nanostructured bainite. Retained austenite, in contrast to its well-known beneficial role, has a deteriorating effect on toughness during the course of Charpy impact. - Highlights: • The microstructure of nanostructured bainite consisted of nano-sized bainitic ferrite subunits with retained austenite films. • Special sample preparations for SEM, XRD and TEM were made, and the strain-affected structures have been explored. • Retained austenite films were found to transform into martensite after impact loading, as evidenced by XRD and TEM results. • The zone of strain-induced martensite was found to extend to only several micrometers from the fracture surface. • The poor Charpy impact toughness is associated with the fracture of martensite at a high strain rate during

  5. A report on the instrumented Charpy impact test for metallic materials

    International Nuclear Information System (INIS)

    An instrumented testing method has been developed for Charpy impact test for steels, aluminum alloys and other materials. Using the instrumented Charpy testing machine developed, it is clearly estimated that the method is good enough to give us detailed information about the impact properties of these metallic materials. (author)

  6. Charpy impact test of cloth reinforced epoxide resin at low temperature

    International Nuclear Information System (INIS)

    Charpy impact tests are made on commercial epoxide resin, glass cloth reinforced epoxide and carbon cloth reinforced epoxide at liquid nitrogen temperature and RT. The samples are described, the tests and results presented and illustrated with relevant halftones. The effects of impact velocity and of off-axis angle on the samples are presented. Four conclusions are formulated

  7. Magnetic system for the quality control of specimens for Charpy impact test

    Science.gov (United States)

    Martin, R. V.; Castanho, M. A. P.

    2015-10-01

    It was developed a non-destructive testing system based on magnetic methods for characterization of steel specimens, used in calibration of Charpy impact testing machines. The magnetic properties saturation, remanence, coercivity, and the hysteresis curves were used to create a "magnetic signature" of reference to ensure the value of energy absorbed by these standard specimens.

  8. The production of calibration specimens for impact testing of subsize Charpy specimens

    International Nuclear Information System (INIS)

    Calibration specimens have been manufactured for checking the performance of a pendulum impact testing machine that has been configured for testing subsize specimens, both half-size (5.0 x 5.0 x 25.4 mm) and third-size (3.33 x 3.33 x 25.4 mm). Specimens were fabricated from quenched-and-tempered 4340 steel heat treated to produce different microstructures that would result in either high or low absorbed energy levels on testing. A large group of both half- and third-size specimens were tested at -40 degrees C. The results of the tests were analyzed for average value and standard deviation, and these values were used to establish calibration limits for the Charpy impact machine when testing subsize specimens. These average values plus or minus two standard deviations were set as the acceptable limits for the average of five tests for calibration of the impact testing machine

  9. Charpy impact test of cloth reinforced epoxide resin at low temperatures

    International Nuclear Information System (INIS)

    This chapter attempts to establish a method for obtaining dynamic toughness and to provide basic data for design, using the Charpy impact test at cryogenic temperatures and an epoxide and FRP with epoxide matrix as samples. Examines the failure mechanism and the potential problems associated with the use of these materials in practical applications in superconducting magnets. Concludes that impact strength at room temperature (RT) has larger values than those at liquid nitrogen temperature irrespective of impact velocity; impact strength can be improved by reinforcement using glass or carbon cloths; impact strength of reinforced plastics shows a dependence on off-axis angle and the dependence varies with the type of reinforcement, matrix and specimens shape; and impact strength of glass reinforced plastic (GRP) is larger than that of GRP when the specimen shape is identical

  10. Charpy impact test results of ferritic alloys from the HFIR-MFE-RB2 test

    International Nuclear Information System (INIS)

    Miniature Charpy specimens of HT-9 in base metal, weld metal and heat affected zone (HAZ) metal conditions, and 9Cr-1Mo in base metal and weld metal conditions have been tested following irradiation in HFIR-MFE-RB2 at 550C to ≅10 dpa. All specimen conditions have degraded properties (both DBTT and USE) in comparison with specimens irradiated to lower dose. 9Cr-Mo degraded more than HT-9 and weld metal performed worse than base metal which performed worse than HAZ material. Property degradation was approximately linear as a function of dose, indicating that degradation response had not saturated by 10 dpa. 6 refs., 2 figs., 2 tabs

  11. Tensile testing and scanning electron microscope examination of Charpy impact specimens from the HFBR

    International Nuclear Information System (INIS)

    The Materials Technology Group of the Department of Nuclear Energy (DNE) at Brookhaven National Laboratory (BNL) has performed a fractographic examination of neutron irradiated and unirradiated Charpy ''V'' notch specimens which have been deformed to failure in a tensile testing apparatus. The evaluation was carried out using a scanning electron microscope (SEM) to evaluate the fracture mode. Photomicrographs were then evaluated to determine if ductile areas were present on the fracture surfaces of the specimens. The irradiated tensile tests (Charpy ''V'' notch configuration) showed minimum notch tensile strengths of 37.2 Ksi before failure. The unirradiated 6061 T-6 material exhibited a minimum notch tensile strength of 41.9 Ksi. 2 refs., 21 figs., 1 tab

  12. Effects of V-notch dimensions on charpy impact test results for differently sized miniature specimens of ferritic steel

    International Nuclear Information System (INIS)

    In order to develop the small specimen technology in Charpy impact testing, the effects of V-notch dimensions on the test results were investigated for miniaturized specimens of a ferritic steel, Japanese Ferrite/Martensite Dual Phase Steel (JFMS). The miniaturized Charpy specimens had four different square cross-sections of 3.3, 2, 1.5 and 1 mm, and each of them had a variety of V-notch dimensions (notch depth, notch root radius and notch angle). All of the specimens were subjected to Charpy impact tests between 93 and 373 K using a specially instrumented impact machine. The fracture surfaces of all tested specimens were examined by scanning electron microscopy. The main results obtained are as follows: (1) The ductile-to-brittle transition temperature (DBTT) varied noticeably depending upon the notch dimensions, some of the DBTTs exceeding that of the full size specimens. (2) The DBTTs for the miniaturized specimens were uniquely defined by the elastic stress concentration factor, Kt, leading to an important aspect that the DBTT for the full size specimens can be directly obtained from the DBTT of the miniaturized specimens with a V-notch giving a suitable value of Kt. (3) The upper shelf energy (USE) was dependent only on notch depth or ligament size, indicating that the notch geometry was practically unimportant. When all of the measured USEs were normalized by Bb2 or (Bb)3/2 (B is the specimen thickness, b the ligament size), the normalized USEs of the miniaturized specimens agreed with that of the full size specimens within the range of ±15% except for one specimen whose notch root radius was as large as 0.25 mm. (4) The observed characteristics of fracture surface were essentially the same as those of the full size specimens. The measurement of lateral expansion, or ductility, was more useful in estimating the impact property of JFMS than that of fracture appearance (fibrous fracture). (author)

  13. Fractographic examination of Charpy impact specimens from the HFIR-MFE-RB2 test

    International Nuclear Information System (INIS)

    The objective of this work is to determine the effect of low temperature irradiation in HFIR on the properties of ferritic stainless steels in order to determine the applicability of these alloys as first wall materials. Selected fracture surfaces of miniature Charpy specimens of HT-9 in base metal, weld metal and heat affected zone (HAZ) metal conditions, and 9Cr-1Mo in base metal and weld metal conditions have been examined by scanning electron microscopy following irradiation in High Flux Isotope Reactor-Magnetic Fusion Energy-RB2 at 550C to 10 dpa. Hardness measurements have also been made. Comparison of results with results on specimens irradiated to low dose demonstrates only minor changes in fracture behavior, but continued increases in hardness due to irradiation. Therefore, the mechanism controlling the degradation of impact properties does not affect the fracture path but does affect strength. A mechanism is proposed to explain the behavior based on microchemical segregation of carbide forming elements. 5 references, 10 figures, 1 table

  14. Charpy impact test results of ferritic alloys from the HFIR[High Flux Isotope Reactor]-MFE-RB2 test

    International Nuclear Information System (INIS)

    Miniature Charpy specimens of HT-9 in base metal, weld metal and heat affected zone (HAZ) metal conditions, and 9Cr-1Mo in base metal and weld metal conditions have been tested following irradiation in HFIR-MFE-RB2 at 550C to ≅10 dpa. All specimen conditions have degraded properties (both DBTT and USE) in comparison with specimens irradiated to lower dose. 9Cr-Mo degraded more than HT-9 and weld metal performed worse than base metal which performed worse than HAZ material. Property degradation was approximately linear as a function of dose, indicating that degradation response had not saturated by 10 dpa

  15. Charpy impact test results for low activation ferritic alloys irradiated to 30 dpa

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Laboratory, Richland, WA (United States)

    1996-04-01

    Miniature specimens of six low activation ferritic alloys have been impact field tested following irradiation at 370{degrees}C to 30 dpa. Comparison of the results with those of control specimens and specimens irradiated to 10 dpa indicates that degradation in the impact behavior appears to have saturated by {approx}10 dpa in at least four of these alloys. The 7.5Cr-2W alloy referred to as GA3X appears most promising for further consideration as a candidate structural material in fusion reactor applications, although the 9Cr-1V alloy may also warrant further investigation.

  16. Effect of Local Crystallographic Texture on the Fissure Formation During Charpy Impact Testing of Low-Carbon Steel

    Science.gov (United States)

    Ghosh, Abhijit; Patra, Sudipta; Chatterjee, Arya; Chakrabarti, Debalay

    2016-03-01

    The severity of the formation of fissures (also known as splitting or delamination) on the fracture surface of Charpy impact-tested samples of a low-carbon steel has been found to increase with the decrease in finish rolling temperature [1093 K to 923 K (820 °C to 650 °C)]. Combined scanning electron microscopy and electron back-scattered diffraction study revealed that crystallographic texture was the prime factor responsible for the fissure formation. Through-thickness texture band composed of cube [Normal Direction (ND)║] and gamma [ND║] orientations developed during the inter-critical rolling treatment. Strain incompatibility between these two texture bands causes fissure cracking on the main fracture plane. A new approach based on the angle between {001} planes of neighboring crystals has been employed in order to estimate the `effective grain size,' which is used to determine the cleavage fracture stress on different planes of a sample. The severity of fissure formation was found to be directly related to the difference in cleavage fracture stress between the `main fracture plane' and `fissure plane.' Clustering of ferrite grains having cube texture promoted the fissure crack propagation along the transverse `fissure plane,' by increasing the `effective grain size' and decreasing the cleavage fracture stress on that plane.

  17. Effect of Local Crystallographic Texture on the Fissure Formation During Charpy Impact Testing of Low-Carbon Steel

    Science.gov (United States)

    Ghosh, Abhijit; Patra, Sudipta; Chatterjee, Arya; Chakrabarti, Debalay

    2016-06-01

    The severity of the formation of fissures (also known as splitting or delamination) on the fracture surface of Charpy impact-tested samples of a low-carbon steel has been found to increase with the decrease in finish rolling temperature [1093 K to 923 K (820 °C to 650 °C)]. Combined scanning electron microscopy and electron back-scattered diffraction study revealed that crystallographic texture was the prime factor responsible for the fissure formation. Through-thickness texture band composed of cube [Normal Direction (ND)║] and gamma [ND║] orientations developed during the inter-critical rolling treatment. Strain incompatibility between these two texture bands causes fissure cracking on the main fracture plane. A new approach based on the angle between {001} planes of neighboring crystals has been employed in order to estimate the `effective grain size,' which is used to determine the cleavage fracture stress on different planes of a sample. The severity of fissure formation was found to be directly related to the difference in cleavage fracture stress between the `main fracture plane' and `fissure plane.' Clustering of ferrite grains having cube texture promoted the fissure crack propagation along the transverse `fissure plane,' by increasing the `effective grain size' and decreasing the cleavage fracture stress on that plane.

  18. Enhancement of Charpy impact value by electron beam irradiation of carbon fiber reinforced polymer

    International Nuclear Information System (INIS)

    Influences of electron beam irradiation on Charpy impact value of carbon fiber reinforced polymer (CFRP) have been investigated. The irradiation, which is one of short-time treatments, enhanced the Charpy impact value of CFRP. Furthermore, strengthening of carbon fiber, ductility enhancement of polymer and interface effects on impact test explains the impact value enhancement of CFRP. (author)

  19. Comparison of impact test results on small and ISO-V type Charpy specimens

    International Nuclear Information System (INIS)

    The ductile-to-brittle transition temperatures were calculated from the impact energies measured on ISO-V and KLST specimens for some non-irradiated, irradiated and both irradiated and annealed quenched and tempered pressure vessel steels at the proposed energy levels 68 J/41 J and 3.1 J/1.9 J, or 28 J and 3.15 J. At the energy levels derived from the mean upper shelf energy (USE) ratio (3.1 J/1.9 J) the transition temperatures were on the average 64 deg. C lower as compared with those measured on the ISO-V specimen. At the energy level 3.15 J derived from the ligament area the transition temperature was on the average 36 deg. C lower than that measured on the ISO-V specimen. For both criteria the standard deviation of the correlation was about 15 deg. C. A procedure was also proposed for calculating the USE of ISO-V specimen from the value measured on the KLST specimen. The transition temperature shifts measured for the irradiated materials on the KLST specimen were up to 30 - 40 deg. C lower than those measured on the ISO-V specimens when the shifts were measured at the levels below 75% USE. The degrees of recovery measured on the KLST specimens were of the same order of magnitude or lower than those measured on the ISO-V specimens. (author). 6 refs, 6 figs

  20. Charpy impact test results of four low activation ferritic alloys irradiated at 370 degrees C to 15 DPA

    International Nuclear Information System (INIS)

    Miniature CVN specimens of four low activation ferritic alloys have been impact tested following irradiation at 370 degrees C to 15 dpa. Comparison of the results with those of control specimens indicates that degradation in the impact behavior occurs in each of these four alloys. The 9Cr-2W alloy referred to as GA3X and the similar alloy F82H with 7.8Cr-2W appear most promising for further consideration as candidate structural materials in fusion energy system applications. These two alloys exhibit a small DBTT shift to higher temperatures but show increased absorbed energy on the upper shelf

  1. Charpy impact test results of four low activation ferritic alloys irradiated at 370{degrees}C to 15 DPA

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, L.E.; Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-10-01

    Miniature CVN specimens of four low activation ferritic alloys have been impact tested following irradiation at 370{degrees}C to 15 dpa. Comparison of the results with those of control specimens indicates that degradation in the impact behavior occurs in each of these four alloys. The 9Cr-2W alloy referred to as GA3X and the similar alloy F82H with 7.8Cr-2W appear most promising for further consideration as candidate structural materials in fusion energy system applications. These two alloys exhibit a small DBTT shift to higher temperatures but show increased absorbed energy on the upper shelf.

  2. Tensile and charpy impact properties of irradiated reduced-activation ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    Tensile tests were conducted on eight reduced-activation Cr-W steels after irradiation to 15-17 and 26-29 dpa, and Charpy impact tests were conducted on the steels irradiated to 26-29 dpa. Irradiation was in the Fast Flux Test Facility at 365{degrees}C on steels containing 2.25-12% Cr, varying amounts of W, V, and Ta, and 0.1%C. Previously, tensile specimens were irradiated to 6-8 dpa and Charpy specimens to 6-8, 15-17, and 20-24 dpa. Tensile and Charpy specimens were also thermally aged to 20000 h at 365{degrees}C. Thermal aging had little effect on the tensile behavior or the ductile-brittle transition temperature (DBTT), but several steels showed a slight increase in the upper-shelf energy (USE). After {approx}7 dpa, the strength of the steels increased and then remained relatively unchanged through 26-29 dpa (i.e., the strength saturated with fluence). Post-irradiation Charpy impact tests after 26-29 dpa showed that the loss of impact toughness, as measured by an increase in DBTT and a decrease in the USE, remained relatively unchanged from the values after 20-24 dpa, which had been relatively unchanged from the earlier irradiations. As before, the two 9Cr steels were the most irradiation resistant.

  3. Relation between Charpy impact properties and magnetism in thermally aged Fe-Cu model alloys

    International Nuclear Information System (INIS)

    This study demonstrates the possibility of applying magnetic methods to pressure vessel surveillance for irradiation embrittlement at nuclear power plants. Charpy impact test and magnetic hesteresis measurement were preformed on thermally aged Fe-1.0wt%Cu model alloys with and without pre-deformation. DBTT increased with increasing aging time. However, magnetic hysteresis parameters showed nonmonotonical changes. The phenomena are discussed in terms of Cu precipitation behavior and dislocation structure. (author)

  4. Evaluation of Charpy impact properties and fracture toughness for irradiated ferritic steels (4)

    International Nuclear Information System (INIS)

    In order to evaluate the radiation-induced shift of fracture toughness from Charpy impact test results for miniaturized specimens, all of the Charpy impact data on high-strength ferritic steels developed by JNC were examined on the basis of the recent progress on the Charpy impact and fracture toughness test methods. Main results obtained are as follows. 1. The radiation-induced shift of fracture toughness is characterized by the shift of the reference fracture toughness temperature, ΔT100, where T100 is the temperature at which the fracture toughness value is 100MPa√ m. ΔT100 is approximately equal to the radiation-induced shift of Charpy DBTT at 41J (ΔT41). Therefore, ΔT100 can be estimated by determining ΔT41 from miniaturized Charpy specimen data. 2. The value of T41 for miniaturized specimens, T41M, can be determined as the test temperature where the absorbed energy is equal to 41/αx[(Bb)3/2F/(Bb)3/2M]. Here, B is the specimen thickness, b is the ligament size and αx[(Bb)3/2F/(Bb)3/2M] is the normalization factor to get the upper shelf energy of full size specimens, USEF, from the mini-size USEM. The values of α is larger than 0.65, depending on the USE of the material. It is also shown that the fracture volume of (Bb)3/2 is more valid than that of Bb2. 3. The following relationship appears to hold between T41F and T41M. T41F - T41M=M=98 - 15.1xln(Bb)3/2, where M is the specimen size correction factor. M also depends on notch geometry and its dependence becomes large with decreasing specimen size. This indicates that the value of T41F can be estimated from T41M by choosing suitable notch geometry. 4. The radiation-induced shift of T41F, ΔT41F, is approximately equal to ΔT41M. This indicates that the estimate of ΔT100 can be made from ΔT41M. 5. For all of the miniaturized Charpy specimen data on high-strength ferritic steels that were irradiated in JOYO and tested at Tohoku University, the values of USEF, T41F, ΔT41F and ΔT100 were successfully

  5. Correlation of microstructure and charpy impact properties in API X70 and X80 line-pipe steels

    International Nuclear Information System (INIS)

    This study aims at correlating microstructure and Charpy impact properties in high-toughness API X70 and X80 line-pipe steels. Three kinds of steels were fabricated by varying alloying elements and hot rolling conditions, and their microstructures and Charpy impact properties were investigated. In addition, their effective grain sizes were characterized by the electron back-scatter diffraction (EBSD) analysis. The Charpy impact test results indicated that the steels rolled in the single phase region had the higher upper shelf energy (USE) than the steel rolled in the two phase region because their microstructures were composed of acicular ferrites. In the X80 steel rolled in the single phase region, the decreased energy transition temperature (ETT) could be explained by the decrease in the overall effective grain size due to the presence of acicular ferrite having smaller effective grain size. Thus, it had excellent mechanical properties in yield and tensile strengths, absorbed energy, and transition temperature, except in ductility

  6. Confocal microscopy-fracture reconstruction and finite element modeling characterization of local cleavage toughness in a ferritic/martensitic steel in subsized Charpy V-notch impact tests

    International Nuclear Information System (INIS)

    The confocal microscopy (CM)-fracture reconstruction (FR) method, coupled with scanning electron microscopy (SEM) fractography, was used to measure the critical notch deformation conditions at cleavage initiation for two subsized Charpy V-notch (CVN) specimen geometries of Japan ferritic/martensitic steel (JFMS). A new method was developed to permit FR of notched specimens. Three-dimensional finite element analysis (FEA) simulations of the notch and specimen deformation were used to estimate values of critical micro-cleavage fracture stress, σ*, and critical stressed area, A*. Since σ*-A* is independent of size and geometry, it provides a fundamental local measure of cleavage toughness

  7. Validation Study of Unnotched Charpy and Taylor-Anvil Impact Experiments using Kayenta

    Energy Technology Data Exchange (ETDEWEB)

    Kamojjala, Krishna [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lacy, Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chu, Henry S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Brannon, Rebecca [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    Validation of a single computational model with multiple available strain-to-failure fracture theories is presented through experimental tests and numerical simulations of the standardized unnotched Charpy and Taylor-anvil impact tests, both run using the same material model (Kayenta). Unnotched Charpy tests are performed on rolled homogeneous armor steel. The fracture patterns using Kayenta’s various failure options that include aleatory uncertainty and scale effects are compared against the experiments. Other quantities of interest include the average value of the absorbed energy and bend angle of the specimen. Taylor-anvil impact tests are performed on Ti6Al4V titanium alloy. The impact speeds of the specimen are 321 m/s and 393 m/s. The goal of the numerical work is to reproduce the damage patterns observed in the laboratory. For the numerical study, the Johnson-Cook failure model is used as the ductile fracture criterion, and aleatory uncertainty is applied to rate-dependence parameters to explore its effect on the fracture patterns.

  8. 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)

    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 1016 neutrons/cm2 (> 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

  9. Charpy impact properties of stainless steel weldment in liquefied natural gas pipelines: Effect of low temperatures

    International Nuclear Information System (INIS)

    Highlights: • Low-temperature impact properties of welded stainless steel pipe were investigated. • Microstructure and impact properties of FCC and BCC structured steels were compared. • Microstructural investigation was performed under varying temperature conditions. • Relatively higher absorbed energy in the welded zone was observed and discussed. - Abstract: In this study, an austenitic stainless steel pipe for the transportation of liquefied natural gas (LNG) was gas tungsten arc welded with a wall thickness of 15.1 mm. Low-temperature Charpy V-notch (CVN) impact tests were performed to investigate the effect of low temperatures on the fracture toughness of the welded zone (WZ), heat-affected zone (HAZ), and base metal (BM) of the LNG pipe. For design and safety reasons, it is necessary to investigate the low-temperature impact properties of weld metals, because weld metals have higher susceptibility to embrittlement than their counterpart base metals. In addition, the effects of cubic crystal structures on the CVN impact response were examined to compare the absorbed energy and fracture surfaces of the materials. Charpy impact tests were performed on mild steels with body-centered cubic (BCC) crystal structures for comparison with the test results of welded austenitic stainless steels with face-centered cubic (FCC) crystal structures. The applicable temperatures were examined, and a scanning electron microscope was used to examine the fracture surface morphology of V-notched specimens tested under various temperature conditions. The results revealed that the absorbed energy of the WZ was slightly higher than that of the BM and HAZ in the FCC-crystal-structured welded pipe specimens. In addition, the ductile-to-brittle transition temperature of the BCC-crystal-structured mild steels was examined

  10. Study of crack propagation mechanisms during Charpy impact toughness tests on both equiaxed and lamellar microstructures of Ti–6Al–4V titanium alloy

    International Nuclear Information System (INIS)

    The impact toughness of two highly textured rolled plates of Ti–6Al–4V alloy with an α equiaxed and an α lamellar microstructures has been investigated. The results show a strong anisotropy of the fracture energy for both materials and underline that a coincidence of the prismatic planes with the shear bands at the notch tip is favorable for higher fracture energies. Moreover, it is pointed out, as it was already done by previous studies, that the α lamellar microstructure presents higher fracture energy than the α equiaxed one. Thanks to electron back scattering diffraction, and tensile tests, local microstructure heterogeneities, called macrozones, have been observed and characterized. Their size depends on microstructure element and is larger for α lamellar microstructure than for the α equiaxed. High strain is localized on the macrozones favorably oriented for prismatic slip with respect to the direction of impact and leads to a particular dimple free zone on the fracture surface. The contribution of these macrozones in the fracture behavior, and more precisely on the crack propagation rate was evaluated; thus the effects of the macroscopic texture and of the microstructure element on the impact toughness are discussed separately

  11. 系列冲击试验转变温度的意义及其局限性%Significance and limitations of transition temperature based on series Charpy impact tests

    Institute of Scientific and Technical Information of China (English)

    马伟; 姜自强; 姜安婕

    2011-01-01

    文章采用双曲正切函数模型,对夏比冲击试验转变温度曲线的数学特征和各种定义的转变温度的物理意义进行了分析探讨,明确了以转变温度曲线比较材料低温韧性的2个基本原则,提出指标转变温度的相对性概念和相对指标转变温度定义的严重缺陷,在重要场合,应以2种以上类型的转变温度予以验证,ASTME185给出的方法值得借鉴.%Mathematical characteristics of transition temperature curve and physical significance of several definitions of transition temperature based on Charpy impact tests are analyzed by using the hyperbolic tangent function model. Two principles in comparing low temperature toughness of materials in light of transition temperature curve are proposed. The relativity of temperature transition indexes is discussed and the limitations of the definition of the relative temperature transition indexes is pointed out. In some important situations, verification should be carried out based on two or more types of transition temperature and the method given by ASTM E185 is useful.

  12. Evaluation of hydrogen embrittlement and temper embrittlement by key curve method in instrumented Charpy test

    Directory of Open Access Journals (Sweden)

    Makita A.

    2010-06-01

    Full Text Available Instrumented Charpy test was conducted on small sized specimen of 21/4Cr-1Mo steel. In the test the single specimen key curve method was applied to determine the value of fracture toughness for the initiation of crack extension with hydrogen free, KIC, and for hydrogen embrittlement cracking, KIH. Also the tearing modulus as a parameter for resistance to crack extension was determined. The role of these parameters was discussed at an upper shelf temperature and at a transition temperature. Then the key curve method combined with instrumented Charpy test was proven to be used to evaluate not only temper embrittlement but also hydrogen embrittlement.

  13. Irradiation programme MANITU: Results of pre-examinations and Charpy tests with unirradiated materials

    International Nuclear Information System (INIS)

    The irradiation project MANITU was planned in the frame of the European Long-term Fusion Materials Development Programme. The results of MANITU will have a lasting influence on the future actions within the materials development programme. The problem of the irradiation induced embrittlement of possible martensitic alloy candidates is still unsolved. But after the evaluation of sub-size Charpy tests with the unirradiated refrence specimens of MANITU a first tendency is recognizable. The Charpy properties of the newly developed low activation 7-10% Cr-WVTa alloys are clearly better compared with the modified commerical 10-11% Cr-NiMoVNb steels. In the present report the pre-examinations are documented and the Charpy test results with unirradiated reference specimens are analysed and assessed. (orig.)

  14. Laser weld reconstitution of conventional Charpy and Miniaturized Notch Test (MNT) specimens

    International Nuclear Information System (INIS)

    As nuclear power plants approach end-of-license (EOL) and consideration is given to license renewal, there is an ever increasing need to expand the amount of data obtainable from the original surveillance specimens. A laser welding technique to reconstitute broken Charpy specimens is being developed to produce both conventional and miniaturized Charpy specimens. This paper reports on early laser welding development efforts and summarizes previous proof-of-principle experiments on a 1/16 scale miniaturized Charpy test. In order to benchmark the laser welding procedure, the laser-reconstituted specimen data have been compared with the original specimen data. In addition, the microstructure after welding has been examined to ensure that the material in the vicinity of the notch is essentially unchanged after the welding process. Data which characterize the thermal transient during welding are obtained by attaching thermocouples to the specimens. Other important considerations include perturbation of the stress field near the notch, dynamic stress waves, and contact of the weld region with the tup. Precise control of welding parameters has been demonstrated, heat-affected zones as small as 0.25 mm can be achieved, and sufficient penetration depth can be obtained to enable welding thick sections (1T or greater) to yield conventional Charpy specimens or fracture toughness specimens and thin sections (∼5 mm) to yield Miniaturized Notch Test (MNT) specimens

  15. A reassessment of the effects of helium on Charpy impact properties of ferritic/martensitic steels

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.; Hamilton, M.L. [Pacific Northwest National Lab., Richland, WA (United States); Hankin, G.L. [Loughborough Univ. (United Kingdom)

    1998-03-01

    To test the effect of helium on Charpy impact properties of ferritic/martensitic steels, two approaches are reviewed: quantification of results of tests performed on specimens irradiated in reactors with very different neutron spectra, and isotopic tailoring experiments. Data analysis can show that if the differences in reactor response are indeed due to helium effects, then irradiation in a fusion machine at 400 C to 100 dpa and 1000 appm He will result in a ductile to brittle transition temperature shift of over 500 C. However, the response as a function of dose and helium level is unlikely to be simply due to helium based on physical reasoning. Shear punch tests and microstructural examinations also support this conclusion based on irradiated samples of a series of alloys made by adding various isotopes of nickel in order to vary the production of helium during irradiation in HFIR. The addition of nickel at any isotopic balance to the Fe-12Cr base alloy significantly increased the shear yield and maximum strengths of the alloys. However, helium itself, up to 75 appm at over 7 dpa appears to have little effect on the mechanical properties of the alloys. This behavior is instead understood to result from complex precipitation response. The database for effects of helium on embrittlement based on nickel additions is therefore probably misleading and experiments should be redesigned to avoid nickel precipitation.

  16. Evaluation of Charpy impact properties and fracture toughness for irradiated ferritic steels. 2

    International Nuclear Information System (INIS)

    The instrumented Charpy impact test was performed for two PMC-FM steels, 61FK and 61FS, irradiated at 723 K to 9.0 x 1026 n/m2 (E > 0.1 MeV) in SMIR-10, and the other two steels, ASTM A213T9 and NSCR9, irradiated at 723 K to 3.6 x 1026 n/m2 in SMIR-10. The test was also conducted for unirradiated 61FK. The absorbed energy, dynamic yield load, dynamic maximum load and brittle fracture load were measured as a function of test temperature and the ductile-to-brittle transition temperature (DBTT) and the upper shelf energy (USE) were evaluated. The DBTT was determined in three different ways; the temperature at which the total absorbed energy was one half of USE (DBTT1), the temperature at which the dynamic yield and maximum loads were equal (DBTT2), and the temperature at which the total absorbed energy was equal to 2 J which corresponds to 10 J for full size specimens (DBTT3). For the test, Charpy V-notch specimens, JIS-4, were used which had the dimensions of 10 x 2 x 55 mm and the V-notch geometry of notch root radius of 0.25 mm, notch depth of 2 mm and notch angle of 45 degrees. Main results obtained are as follows. 1) The DBTT showed that DBTT1>DBTT2>DBTT3 for 61FK, 61FS and NSCR9. 2) For unirradiated 61FK the DBTT1 was 202 K and the USE was 16.9 J, while for irradiated 61FK the DBTT1 was 249 K and the USE was 10.8 J. Therefore, the irradiation caused the DBTT1 to increase by 47 K and the USE to decrease by 6.1 J. 3) For irradiated 61FS the DBTT1 was 207 K and the USE was 17.0 J. Since the DBTT1 and USE of unirradiated 61FS were 160 K and 20 J, respectively, it followed that the irradiation caused the DBTT1 to increase by 47 K and the USE to decrease by 3 J. 4) For irradiated F9S the DBTT1 was 166 K and the USE was 21.4 J. 5) For irradiated NSCR9 the DBTT1 was 208 K and the USE was 16.2 J. Since the DBTT1 and USE of unirradiated NSCR9 were 185 K and 16 J, respectively, it followed that the irradiation caused the DBTT1 to increase by 23 K but no decrease in USE. (J.P.N.)

  17. Response of unirradiated and neutron-irradiated vanadium alloys to Charpy-impact loading

    International Nuclear Information System (INIS)

    The ductile-brittle transition temperature (DBTT) was determined by Charpy-impact impact tests for dehydrogenated (<30 appm H) and hydrogenated (400--1200 appm H) V-7.2Cr-14.5Ti, V-9.9Cr-9.2Ti, V-13.5Cr-5.2Ti, V-17.7Ti, V-9.2Cr-4.9Ti, V-9.0Cr-3.2Fe-1.2Zr, V-3.1Ti-0.5Si, V-4.1Cr-4.3Ti, V-4.6Ti, and V-2.5Ti-1.0Si alloys. The DBTT was also determined for the V-13.5Cr-5.2Ti, V-9.2Cr-4.9Ti, V-7.2Cr-14.5Ti, and V-17.7Ti alloys after neutron irradiation at 420 and 600 degrees C to 41--44 atom displacements per atom. The DBTTs determined for these vanadium alloys show that a vanadium alloy containing Cr and/or Ti and Si alloying additions to be used as a structural material in a fusion reactor should contain 3--11 wt % total alloying addition for maximum resistance to hydrogen- and/or irradiation-induced embrittlement. 4 refs., 3 figs., 2 tabs

  18. Charpy impact energy evolution, with sensitization treatments, in absence and presence of internal hydrogen in austenitic 304 L

    International Nuclear Information System (INIS)

    Charpy impact energy measurement is a sensitive method, specially at low temperature (-180+-50C), to evaluate the sensitization treatments on austenitic 304 L, in presence or absence of cathodic hydrogen

  19. Evaluation of hydrogen embrittlement and temper embrittlement by key curve method in instrumented Charpy test

    OpenAIRE

    Makita A.; Shindo Y.; Ohtsuka N.

    2010-01-01

    Instrumented Charpy test was conducted on small sized specimen of 21/4Cr-1Mo steel. In the test the single specimen key curve method was applied to determine the value of fracture toughness for the initiation of crack extension with hydrogen free, KIC, and for hydrogen embrittlement cracking, KIH. Also the tearing modulus as a parameter for resistance to crack extension was determined. The role of these parameters was discussed at an upper shelf temperature and at a transition temperat...

  20. Evaluation of Charpy impact properties and fracture toughness for irradiated ferritic steels (3)

    International Nuclear Information System (INIS)

    Four kinds of ferritic steels, 61FK, 61FS, ASTM A213T9 (F9S) and NSCR9, were irradiated in SMIR-10 at 823 K to (3.2-9.0)x1026 n/m2 (E > 0.1 MeV) and subjected to instrumented Charpy impact tests. The absorbed energy, dynamic yield and maximum loads, brittle fracture load and the deflection to brittle fracture were measured as a function of test temperature and the ductile-to-brittle transition temperature (DBTT) and the upper shelf energy (USE) were evaluated. For the test, Charpy V-notch specimens, JIS-4, were used which had the dimensions of 10x2x55 mm and the V-notch geometry of notch root radius of 0.25 mm, notch of 2 mm and notch angle of 45 degrees. Main results obtained are as follows. 1) The DBTT was less dependent on neutron dose. The DBTT for the higher dose of (8.8-9.0)-1026 n/m2 increased in the order of 61FK, NSCR9, 61FS and F9S. 2) As the neutron dose increased, the USE decreased for 61FK, while it stayed almost constant for 61GS and increased for F9S. The USE for the higher dose decreased in the order of 61FK, NSCR9, 61FS and F9S, which was the same as the increasing order of DBTT. 3) The DBTT shifts, ΔDBTT, due to irradiation with the higher dose level increased in the order of 61FK, 61FS and NSCR9, except for F9S, where the DBTT in the unirradiated state is not available. 4) The change in USE, ΔUSE, due to irradiation with the higher dose increased in the order of 61FS, 61FK and NSCR9, except for F9S. 5) Comparison of the present results with the previous ones irradiated at 723K in SMIR-10 showed that 823K irradiation caused considerably larger embrittlement than 723K irradiation, especially for F9S and 61FK. (author)

  1. Identification of neutron irradiation induced strain rate sensitivity change using inverse FEM analysis of Charpy test

    International Nuclear Information System (INIS)

    A simple methodology how to obtain additional information about the mechanical behaviour of neutron-irradiated WWER 440 reactor pressure vessel steel was developed. Using inverse identification, the instrumented Charpy test data records were compared with the finite element computations in order to estimate the strain rate sensitivity of 15Ch2MFA steel irradiated with different neutron fluences. The results are interpreted in terms of activation volume change

  2. Application of Charpy Impact Absorbed Energy to the Safety Assessment Based on SINTAP

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The European Structural Integrity Assessment Procedure(SINTAP) was applied to the assessment of welded joints of the APl 5L X65 pipeline steel with an assumed embedded flaw and surface flaw at the weld toe. At default level( level 0), the assessment point was established by estimating fracture toughness value KIc conservatively from Charpy energy test data. At the same time, the analysis level 1 (basic level)was applied based on the fracture toughness CTOD. Then the two assessment levels were compared. The assessment results show that all assessment points are located within the failure lines of analysis levels 0 and 1. So the welded joint of the pipeline is safe. It can be concluded that the assessment based on Charpy absorbed energy is practicable when other fracture toughness data are not available, or cannot be easily obtained. The results are conservative.

  3. Behavior of Aramid Fiber/Ultrahigh Molecular Weight Polyethylene Fiber Hybrid Composites under Charpy Impact and Ballistic Impact

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The aramid fiber/UHMWPE (ultrahigh molecular weight polyethylene) fiber hybrid composites (AF/DF) were manufactured. By Charpy impact, the low velocity impact behavior of AF/DF composite was studied. And the high velocity impact behavior under ballistic impact was also investigated. The influence of hybrid ratio on the performances of low and high velocity impact was analyzed, and hybrid structures with good impact properties under low velocity impact and high velocity were optimized. For Charpy impact, the maximal impact load increased with the accretion of the AF layers for AF/DF hybrid composites. The total impact power was reduced with the decrease of DF layers and the delamination can result in the increase of total impact power. For ballistic impact, the DF ballistic performance was better than that of the AF and the hybrid ratio had a crucial influence. The failure morphology of AF/DF hybrid composite under Charpy impact and ballistic impact was analyzed. The AF/DF hybrid composites in suitable hybrid ratio could attain better performance than AF or DF composites.

  4. Tensile and Charpy impact behavior of an irradiated three-wire series-arc stainless steel cladding

    International Nuclear Information System (INIS)

    The potential for stainless steel cladding to improve the fracture behavior of an operating nuclear reactor pressure vessel, particularly during certain overcooling transients, may depend greatly on the properties of the irradiated cladding. Therefore, three-wire stainless steel cladding irradiated at temperatures and to fluences relevant to power reactor operation was examined. Postirradiation testing results show that, in the test temperature range from -125 to 288 degrees C, the yield strength increased by 8 to 30%, and ductility insignificantly increased, while there was almost no change in the ultimate tensile strength. All cladding exhibited ductile-to-brittle transition behavior during Charpy impact testing, owing to the dominance of delta-ferrite failures at low temperatures. On the upper shelf, the energy was reduced (owing to irradiation exposure) 15 to 20%, while the lateral expansion was reduced 43 and 41% at 2 and 5 - 1019 n/cm2 (E > 1 MeV), respectively. In addition, radiation damage resulted in 13 and 28 degrees C shifts of the Charpy impact transition temperature at the 41-J level for the low and high fluences, respectively

  5. A New Analytical Expression for the Relationship Between the Charpy Impact Energy and Notch Tip Position for Functionally Graded Steels

    Institute of Scientific and Technical Information of China (English)

    H.Samareh Salavati Pour; F.Berto; Y.Alizadeh

    2013-01-01

    The effect of the distance between the notch tip and the position of the middle phase in the FGSs on the Charpy impact energy is investigated in the present paper.The results show that when the notch apex is close to the middle layer,the Charpy impact energy reaches its maximum value.This is due to the increment of the absorbed energy by plastic deformation ahead of the notch tip.On the other hand,when the notch tip is far from the middle layer,the Charpy impact energy strongly decreases.Another fundamental motivation of the present work is that for crack arrester configuration,no accurate mathematical or analytical modelling is available up to now.By considering the relationship between the Charpy impact energy and the plastic volume size,a new theoretical model has been developed to link the Charpy impact energy with the distance from the notch apex to the middle phase.This model is a simplified one and the effect of different shapes of the layers and the effect of microstructure on the mechanical properties and plastic region size will be considered in further investigation.The results of the new developed closed form expression show a sound agreement with some recent experimental results taken from the literature.

  6. Analysis of Charpy V-notch impact toughness of irradiated A533-B class 1 plate and four submerged-arc welds

    International Nuclear Information System (INIS)

    Studies of the effects of neutron irradiation on Charpy V-notch impact properties of steels have, in general, included a minimum number of tests for each combination of material and irradiation parameters. The present study attempts to apply statistical analyses with multiple testing at selected temperatures to assess the accuracy and reliability of results. Charpy V-notch impact test specimens were irradiated in the Bulk Shielding Reactor at Oak Ridge National Laboratory at 2880C to target neutron fluences of 2 X 1023 neutrons (n)/m2 (>1 MeV). The materials were ASTM A533-B Class 1 plate (HeavySection Steel Technology Plate 02) and four submerged-arc welds representing current nuclear pressure vessel fabrication practice. Both unirradiated and irradiated specimens were tested by two separate groups and multiple tests were conducted at several selected temperatures. Statistical analyses permitted determination of material and test variability and an interlaboratory comparison. Several Charpy curve-fitting methods were used and results are compared with predictions from several ''trend curve'' expressions

  7. Effect of mechanical alloying atmosphere on the microstructure and Charpy impact properties of an ODS ferritic steel

    International Nuclear Information System (INIS)

    Two types of oxide dispersion strengthened (ODS) ferritic steels, with the composition of Fe-14Cr-2W-0.3Ti-0.3Y2O3 (in weight percent), have been produced by mechanically alloying elemental powders of Fe, Cr, W, and Ti with Y2O3 particles either in argon atmosphere or in hydrogen atmosphere, degassing at various temperatures, and compacting the mechanically alloyed powders by hot isostatic pressing. It was found in particular that mechanical alloying in hydrogen yields a significant reduction in oxygen content in the materials, a lower dislocation density, and a strong improvement in the fast fracture properties of the ODS ferritic steels, as measured by Charpy impact tests.

  8. An overview of the principles of modeling Charpy impact energy data using statistical analysis

    International Nuclear Information System (INIS)

    Integrity assessments of Magnox nuclear reactors with steel pressure vessels quantify the temperature margins between the operating temperature of the plant, at any given location, and the onset of upper-shelf temperature. The onset of upper-shelf temperature can be estimated from the fracture toughness properties of each material used in the construction of the pressure vessels. Although start-of-life fracture toughness properties of the materials have been measured, such properties are not available for the neutron-irradiated and thermally aged condition. One of the main effects of neutron irradiation and temperature experienced during service is to increase the ductile-to-brittle transition temperature (DBTT), which can be represented in terms of temperature shifts. In the irradiation surveillance schemes for the Magnox reactors, these temperature shifts can be inferred from Charpy impact energy data which have been measured regularly during the service life. Since Charpy impact energy data are inherently scattered, it is necessary to optimize the interpretation of the data by statistical processing. A recent analysis undertaken by Moskovic et al. concluded that Bayesian analyses are best suited to address the problem. In this overview, the authors consider the requirements of such analyses and the various options available. They then consider the method proposed by Moskovic et al. with respect to the requirements of the inputs to the integrity assessment and the validity of this approach. In this method of analysis, the distribution of all possible values of model coefficients is established by judging the various possible combinations of these model coefficients in relation to the likelihood of the observed data. Analysis of artificially generated data has been used to compare the effectiveness of Bayesian analyses with those used traditionally

  9. Application of Instrumented Charpy Method in Characterisation of Materials

    Directory of Open Access Journals (Sweden)

    Željko Alar

    2015-07-01

    Full Text Available Testing of absorbed impact energy according to the Charpy method is carried out to determine the behaviour of a material under the impact load. Instrumented Charpy method allows getting the force displacement curve through the entire test, That curve can be related to force-displacement curve which is obtained by the static tensile test. The purpose of this study was to compare the results of forces obtained by the static tensile test with the forces obtained by the instrumented Charpy method. Experimental part of the work contains testing of the mechanical properties of S275J0 steel by the static tensile test and Impact test on instrumented Charpy pendulum.

  10. Constraint effects on fracture toughness of impact-loaded, precracked Charpy specimens

    International Nuclear Information System (INIS)

    Impact-loaded, precracked Charpy specimens often play a crucial role in irradiation surveillance programs for nuclear power plants. However, the small specimen size B=W=10 mm limits the maximum value of cleavage fracture toughness Jc that can be measured under elastic-plastic conditions without loss of crack tip constraint. In this investigation, plane strain impact analyses provide detailed resolution of crack tip fields for impact-loaded specimens. Crack tip stress fields are characterized in terms of J-Q trajectories and the toughness-scaling model which is applicable for a cleavage fracture mechanism. Results of the analyses suggest deformation limits at fracture in the form of b>MJc/σ0, where M approaches 25-30 for a strongly rate-sensitive material at impact velocities of 3-6 m s-1. Based on direct comparison of the static and dynamic J values computed using a domain integral formulation, a new proposal emerges for the transition time, the time after impact at which interial effects diminish sufficiently for simple evaluation of J using the plastic η factor approach. (orig.)

  11. Effects of Oxides on Tensile and Charpy Impact Properties and Fracture Toughness in Heat Affected Zones of Oxide-Containing API X80 Linepipe Steels

    Science.gov (United States)

    Sung, Hyo Kyung; Sohn, Seok Su; Shin, Sang Yong; Oh, Kyung Shik; Lee, Sunghak

    2014-06-01

    This study is concerned with effects of complex oxides on acicular ferrite (AF) formation, tensile and Charpy impact properties, and fracture toughness in heat affected zones (HAZs) of oxide-containing API X80 linepipe steels. Three steels were fabricated by adding Mg and O2 to form oxides, and various HAZ microstructures were obtained by conducting HAZ simulation tests under different heat inputs. The no. of oxides increased with increasing amount of Mg and O2, while the volume fraction of AF present in the steel HAZs increased with increasing the no. of oxides. The strengths of the HAZ specimens were generally higher than those of the base metals because of the formation of hard microstructures of bainitic ferrite and granular bainite. When the total Charpy absorbed energy was divided into the fracture initiation and propagation energies, the fracture initiation energy was maintained constant at about 75 J at room temperature, irrespective of volume fraction of AF. The fracture propagation energy rapidly increased from 75 to 150 J and saturated when the volume fraction of AF exceeded 30 pct. At 253 K (-20 °C), the total absorbed energy increased with increasing volume fraction of AF, as the cleavage fracture was changed to the ductile fracture when the volume fraction of AF exceeded 45 pct. Thus, 45 vol pct of AF at least was needed to improve the Charpy impact energy, which could be achieved by forming a no. of oxides. The fracture toughness increased with increasing the no. of oxides because of the increased volume fraction of AF formed around oxides. The fracture toughness did not show a visible correlation with the Charpy absorbed energy at room temperature, because toughness properties obtained from these two toughness testing methods had different significations in view of fracture mechanics.

  12. Miniature Precracked Charpy Specimens for Measuring the Master Curve Reference Temperature of RPV Steels at Impact Loading Rates

    International Nuclear Information System (INIS)

    In the framework of the 2006 Convention, we investigated the applicability of fatigue precracked miniature Charpy specimens of KLST type (MPCC - B = 3 mm, W = 4 mm and L = 27 mm) for impact toughness measurements, using the well-characterized JRQ RPV steel. In the ductile to-brittle transition region, MPCC tests analyzed using the Master Curve approach and compared to data previously obtained from PCC specimens had shown a more ductile behavior and therefore un conservative results. In the investigation presented in this report, two additional RPV steels have been used to compare the performance of impact-tested MPCC and PCC specimens in the transition regime: the low-toughness JSPS steel and the high-toughness 20MnMoNi55 steel. The results obtained (excellent agreement for 20MnMoNi55 and considerable differences between T0 values for JSPS) are contradictory and do not presently allow qualifying the MPCC specimens as a reliable alternative to PCC samples for impact toughness measurements.

  13. Visual interface for the automation of the instrumented pendulum of Charpy tests used in the surveillance program of reactors vessel of nuclear power plants

    International Nuclear Information System (INIS)

    Inside the Programs of Surveillance of the nuclear power stations periodic information is required on the state that keep the materials with those that builds the vessel of the reactor. This information is obtained through some samples or test tubes that are introduced inside the core of the reactor and it is observed if its physical characteristics remain after having been subjected to the radiation changes and temperature. The rehearsal with the instrumented Charpy pendulum offers information on the behavior of fracture dynamics of a material. In the National Institute of Nuclear Research (ININ) it has an instrumented Charpy pendulum. The operation of this instrument is manual, having inconveniences to carry out rehearsals with radioactive material, handling of high and low temperatures, to fulfill the normative ones for the realization of the rehearsals, etc. In this work the development of a computational program is presented (virtual instrument), for the automation of the instrumented pendulum. The system has modules like: Card of data acquisition, signal processing, positioning system, tempered system, pneumatic system, compute programs like it is the visual interface for the operation of the instrumented Charpy pendulum and the acquisition of impact signals. This system shows that given the characteristics of the nuclear industry with radioactive environments, the virtual instrumentation and the automation of processes can contribute to diminish the risks to the personnel occupationally exposed. (Author)

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

    International Nuclear Information System (INIS)

    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

  15. Use of forces from instrumented Charpy V-notch testing to determine crack-arrest toughness

    International Nuclear Information System (INIS)

    The objective of this investigation is an estimation of the crack-arrest toughness, particularly of irradiated materials, from voltage versus time output of an instrumented setup during a test on a Charpy V-notch (CVN) specimen. This voltage versus time trace (which can be converted to force versus displacement) displays events during fracture of the specimen. Various stages of the fracture process can be identified on the trace, including an arrest point indicating arrest of brittle fracture. The force at arrest, Fa, versus test temperature, T, relationship is examined to explore possible relationships to other experimental measures of crack-arrest toughness such as the drop-weight nil-ductility temperature (NDT), or crack-arrest toughness, Ka. For a wide range of weld and plate materials, the temperature at which Fa = 2.45 kN correlates with NDT with a standard deviation, sigma, of about 11 K. Excluding the so-called low upper-shelf energy (USE) welds from the analysis resulted in Fa = 4.12 kN and σ = 6.6 K. The estimates of the correlation of the temperature for Fa = 7.4 kN with the temperature at 100-MPa√m level for a mean American Society of Mechanical Engineers (ASME) type KIa curve through crack-arrest toughness values show that prediction of conservative values of Ka are possible

  16. Instrumented Charpy Impact Property and Analysis of Fracture Surface of Hot Work Tool Steel; Netukan kogu ko no keisoka sharupi shogeki tokusei to hamen kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Yokoi, D.; Tsujii, N. [Sanyo Special Steel Co. Ltd., Hyogo (Japan); Fukaura, K.; Sunada, H. [Himeji Inst.of Tech., Hyogo (Japan)

    1997-06-15

    The effects of hardness and prior austenite grain size on the impact property of hot work tool steel JIS-SKD6 at room temperature were investigated by the analyses of impact fracture surface and of load-deflection diagrams obtained from instrumented Charpy impact test. In order to vary hardness and the grain size, the specimens of SKD6 produced by ingot and powder metallurgy were quenched from different temperatures, i.e., 1303K and 1403K, and then tempered twice at 873K. It was found that most of impact energy was exhausted in crack initiation for every material and the impact fracture modes were divided into three groups. Although the impact energy tended to decrease with increasing hardness, fine-grained structure suppressed the reduction in impact energy due to the enhancement of the resistance to the crack initiation. 2 refs., 11 figs., 2 tabs.

  17. Effects of nonstandard heat treatment temperatures on tensile and Charpy impact properties of carbon-steel casting repair welds

    International Nuclear Information System (INIS)

    This report discusses carbon steel castings which are used for a number of different components in nuclear power plants, including valve bodies and bonnets. Components are often repaired by welding processes, and both welded components and the repair welds are subjected to a variety of postweld heat treatments (PWHT) with temperatures as high as 899 degrees C (1650 degrees F), well above the normal 593 to 677 degrees C (1100 to 1250 degrees F) temperature range. The temperatures noted are above the A1 transformation temperature for the materials used for these components. A test program was conducted to investigate the potential effects of such ''nonstandard'' PWHTs on mechanical properties of carbon steel casting welds. Four weldments were fabricated, two each with the shielded-metal-arc (SMA) and flux-cored-arc (FCA) processes,with a high-carbon and low-carbon filler metal in each case. All four welds were sectioned and given simulated PWHTs at temperatures from 621 to 899 degrees C (1150 to 1650 degrees F) in increments of 56 degrees C (100 degrees F) and for times of 5, 10, 20, and 40 h at each temperature. Hardness, tensile, and Charpy V-notch (CVN) impact tests were conducted for the as-welded and heat-treated conditions

  18. Characterization by notched and precracked Charpy tests of the in-service degradation of RPV steel fracture toughness

    International Nuclear Information System (INIS)

    The current engineering and regulatory practice to estimate fracture toughness safety margins for nuclear reactor pressure vessels (RPVs) relies heavily on the CVN impact test. Techniques to estimate in-service toughness degradation directly using a variety of precracked specimens are under development worldwide. Emphasis is on their miniaturization. In the nuclear context, it is essential to address many issues such as representativity of the surveillance programs with respect to the vessel in terms of materials and environment, transferability of test results to the structure (constraint and size effects), lower bound toughness certification, creadibility relative to trends of exising databases. An enhanced RPV surveillance strategy in under development in Belgium. It combines state-of-the-art micromechanical and damage modelling to the evaluation of CVN load-deflection signals, tensile stress-strain curves and slow-bend tests of reconstituted precracked Charpy specimens. A probabilistic micromechanical model has been established for static and dynamic transgranular cleavage initiation fracture toughness in the ductile-brittle transition temperature range. This model allows to project toughness bounds for any steel embrittlement condition from the corresponding CVN and static tensile properties, using a single scaling factor defined by imposing agreement with toughness tests in a single condition. The outstanding finding incorporated by this toughness transfer model is that the microcleavage fracture stress is affected by temperature in the ductile-brittle transition and that this influence is strongly correlated to the flow stress: this explains the shape of the KIcn KId temperature curves as well as the actual magnitude of the strain rate and irradiation effects. Furthermore, CVN crack arrest loads and fracture appearance are also taken advantage of in order to estimate KIa degradation. Finally, the CVN-tensile load-temperature diagram provides substantial

  19. Characterization by notched and precracked Charpy tests of the in-service degradation of RPV steel fracture toughness

    Energy Technology Data Exchange (ETDEWEB)

    Fabry, A.

    1997-01-01

    The current engineering and regulatory practice to estimate fracture toughness safety margins for nuclear reactor pressure vessels (RPVs) relies heavily on the CVN impact test. Techniques to estimate in-service toughness degradation directly using a variety of precracked specimens are under development worldwide. Emphasis is on their miniaturization. In the nuclear context, it is essential to address many issues such as representativity of the surveillance programs with respect to the vessel in terms of materials and environment, transferability of test results to the structure (constraint and size effects), lower bound toughness certification, creadibility relative to trends of exising databases. An enhanced RPV surveillance strategy in under development in Belgium. It combines state-of-the-art micromechanical and damage modelling to the evaluation of CVN load-deflection signals, tensile stress-strain curves and slow-bend tests of reconstituted precracked Charpy specimens. A probabilistic micromechanical model has been established for static and dynamic transgranular cleavage initiation fracture toughness in the ductile-brittle transition temperature range. This model allows to project toughness bounds for any steel embrittlement condition from the corresponding CVN and static tensile properties, using a single scaling factor defined by imposing agreement with toughness tests in a single condition. The outstanding finding incorporated by this toughness transfer model is that the microcleavage fracture stress is affected by temperature in the ductile-brittle transition and that this influence is strongly correlated to the flow stress: this explains the shape of the K{sub Ic}n K{sub Id} temperature curves as well as the actual magnitude of the strain rate and irradiation effects. Furthermore, CVN crack arrest loads and fracture appearance are also taken advantage of in order to estimate K{sub Ia} degradation. Finally, the CVN-tensile load-temperature diagram

  20. Effects of thermal aging on fracture toughness and Charpy-impact strength of stainless steel pipe welds

    International Nuclear Information System (INIS)

    Degradation of fracture toughness, tensile, and Charpy-impact properties of Type 304 and 304/308 SS pipe welds due to thermal aging was studied at room temperature and 290 C. Thermal aging of SS welds results in moderate decreases in charpy-impact strength and fracture toughness. Upper-shelf energy decreased by 50-80 J/cm2. Decrease in fracture toughness J-R curve or JIC is relatively small. Thermal aging had no or little effect on tensile strength of the welds. Fracture properties of SS welds are controlled by the distribution and morphology of second-phase particles. Failure occurs by formation and growth of microvoids near hard inclusions; such processes are relatively insensitive to thermal aging. The ferrite phase has little or no effect on fracture properties of the welds. Differences in fracture resistance of the welds arise from differences in the density and size of inclusions. Mechanical-property data from the present study are consistent with results from other investigations. The existing data have been used to establish minimum expected fracture properties for SS welds

  1. Effects of thermal aging on fracture toughness and Charpy-impact strength of stainless steel pipe welds

    Energy Technology Data Exchange (ETDEWEB)

    Gavenda, D.J.; Michaud, W.F.; Galvin, T.M.; Burke, W.F.; Chopra, O.K. [Argonne National Lab., IL (United States)

    1996-05-01

    Degradation of fracture toughness, tensile, and Charpy-impact properties of Type 304 and 304/308 SS pipe welds due to thermal aging was studied at room temperature and 290 C. Thermal aging of SS welds results in moderate decreases in charpy-impact strength and fracture toughness. Upper-shelf energy decreased by 50-80 J/cm{sup 2}. Decrease in fracture toughness J-R curve or J{sub IC} is relatively small. Thermal aging had no or little effect on tensile strength of the welds. Fracture properties of SS welds are controlled by the distribution and morphology of second-phase particles. Failure occurs by formation and growth of microvoids near hard inclusions; such processes are relatively insensitive to thermal aging. The ferrite phase has little or no effect on fracture properties of the welds. Differences in fracture resistance of the welds arise from differences in the density and size of inclusions. Mechanical-property data from the present study are consistent with results from other investigations. The existing data have been used to establish minimum expected fracture properties for SS welds.

  2. Effects of thermal aging on fracture toughness and charpy-impact strength of stainless steel pipe welds.

    Energy Technology Data Exchange (ETDEWEB)

    Gavenda, D. J.; Michaud, W. F.; Galvin, T. M.; Burke, W. F.; Chopra, O. K.; Energy Technology

    1996-06-05

    The degradation of fracture toughness, tensile, and Charpy-impact properties of Type 308 stainless steel (SS) pipe welds due to thermal aging has been characterized at room temperature and 290 C. Thermal aging of SS welds results in moderate decreases in Charpy-impact strength and fracture toughness. For the various welds in this study, upper-shelf energy decreased by 50-80 J/cm{sup 2}. The decrease in fracture toughness J-R curve or JIC is relatively small. Thermal aging had little or no effect on the tensile strength of the welds. Fracture properties of SS welds are controlled by the distribution and morphology of second-phase particles. Failure occurs by the formation and growth of microvoids near hard inclusions; such processes are relatively insensitive to thermal aging. The ferrite phase has little or no effect on the fracture properties of the welds. Differences in fracture resistance of the welds arise from differences in the density and size of inclusions. Mechanical-property data from the present study are consistent with results from other investigations. The existing data have been used to establish minimum expected fracture properties for SS welds.

  3. Experimental Investigation of Charpy Impact Tests on Metallic SLM parts

    OpenAIRE

    Yasa, Evren; Deckers, Jan; Kruth, Jean-Pierre; Rombouts, Marleen; Luyten, Jan

    2009-01-01

    Selective laser melting (SLM) is a layer-additive manufacturing technology making it possible to create fully functional parts directly from standard metal powders without using any intermediate binders or any additional post-processing steps. During the process, a laser source selectively scans a powder bed according to the CAD data of the part to be produced and powder particles are completely molten by a high intensity laser beam. SLM is capable of producing near full density metallic part...

  4. Visual interface for the automation of the instrumented pendulum of Charpy tests used in the surveillance program of reactors vessel of nuclear power plants; Interfase visual para la automatizacion del pendulo instrumentado de pruebas Charpy utilizado en el programa de vigilancia de la vasija de reactores de centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Rojas S, A.S.; Sainz M, E.; Ruiz E, J.A. [ININ, Carretera Mexico-Toluca Km.36.5, Mpio. de Ocoyoacac, Estado de Mexico (Mexico)]. E-mail: asrs@nuclear.inin.mx; esm@nuclear.inin.mx; jare@nuclear.inin.mx

    2004-07-01

    Inside the Programs of Surveillance of the nuclear power stations periodic information is required on the state that keep the materials with those that builds the vessel of the reactor. This information is obtained through some samples or test tubes that are introduced inside the core of the reactor and it is observed if its physical characteristics remain after having been subjected to the radiation changes and temperature. The rehearsal with the instrumented Charpy pendulum offers information on the behavior of fracture dynamics of a material. In the National Institute of Nuclear Research (ININ) it has an instrumented Charpy pendulum. The operation of this instrument is manual, having inconveniences to carry out rehearsals with radioactive material, handling of high and low temperatures, to fulfill the normative ones for the realization of the rehearsals, etc. In this work the development of a computational program is presented (virtual instrument), for the automation of the instrumented pendulum. The system has modules like: Card of data acquisition, signal processing, positioning system, tempered system, pneumatic system, compute programs like it is the visual interface for the operation of the instrumented Charpy pendulum and the acquisition of impact signals. This system shows that given the characteristics of the nuclear industry with radioactive environments, the virtual instrumentation and the automation of processes can contribute to diminish the risks to the personnel occupationally exposed. (Author)

  5. Dynamic Toughness Testing of Pre-Cracked Charpy V-Notch Specimens. Convention ELECTRABEL - SCK-CEN

    International Nuclear Information System (INIS)

    This document describes the experimental and analytical procedures which have been adopted at the laboratories of the Belgian Nuclear Research Centre SCK-CEN for performing dynamic toughness tests on pre-cracked Charpy-V specimens. Such procedures were chosen on the basis of the existing literature on the subject, with several updates in the data analysis stages which reflect more recent developments in fracture toughness testing. Qualification tests have been carried out on PCCv specimens of JRQ steel, in order to assess the reliability of the results obtained; straightforward comparisons with reference data have been performed, as well as more advanced analyses using the Master Curve approach. Aspects related to machine compliance and dynamic tup calibration have also been addressed

  6. Effects of oxidation on the impact energy of Hastelloy S and Hastelloy C-4 Charpy V-notch specimens heated in air at 6000 to 8000C

    International Nuclear Information System (INIS)

    The 90SrF2 heat source being developed at PNL utilizes a Hastelloy S or Hastelloy C-4 outer capsule having a 0.5-in.-thick wall to contain the Hastelloy C-276 inner capsule. The primary objective of the study was to demonstrate that the air oxidation of the outer capsule that could occur during heat-source service would not degrade the ductility and Charpy impact strength of the capsule below the licensing requirements given in Section 1.1. The 90SrF2 heat source under development is intended for general-purpose use. Compatibility considerations limit the interface temperature between the 90SrF2 and Hastelloy C-276 inner capsule to a maximum of 8000C. The outer capsule surface temperature will be somewhat less than 8000C, and depending on the service, may be substantially lower. The oxidation tests were therefore carried out at 6000 to 8000C for exposures up to 10,000h to cover the range of temperature the outer capsule might expect to encounter in service. The results showed that the oxidation of Hastelloy S and Hastelloy C-4 in air at 6000 to 8000C is very slow, and both alloys form adherent oxide layers that serve to protect the underlying metal. Subsurface attack of Hastelloy S and Hastelloy C-4 due to oxidation was greater than expected, considering the slow oxidation rates of the two alloys at 6000 to 8000C. Estimates of subsurface attack, determined from micrographs of the oxidized specimens, showed erratic results and it was impossible to assign any type of rate equation to the subsurface attack. A conservative estimate of long-term effects can be made using a linear extrapolation of the test results. There were no significant differences between the room-temperature Charpy impact energy of Hastelloy S and Hastelloy C-4 specimens oxidized in air at 6000 to 8000C and control specimens heated in vacuum

  7. Reconstitution technology of Charpy surveillance specimens with short insert length

    International Nuclear Information System (INIS)

    As for the shortage of the surveillance specimens to monitor the effect of the irradiation embrittlement of reactor pressure vessels (RPV) materials in case of longer-term operation than present surveillance program of nuclear power plants, the reconstitution of them is considered to be the promising measures. Although the length of the specimen insert is required not less than 18 mm in ASTM E1253-99 which is the technical standard to reconstitute Charpy specimens, the minimum length of the specimen insert required should be 10 mm when L-T direction Charpy specimens that have been applied to the early domestic nuclear power plants are reconstituted into T-L direction specimens in order to test the upper shelf absorbed energy of T-L direction specimens. This paper presents the current status of the research consigned by Ministry of Economy, Trade and Industry (METI) in Japan on the applicability of the reconstituted Charpy specimens with short length of the specimen insert. The length of the specimen insert to preserve the absorbed energy of the Charpy specimen is correlated to the absorbed energy of its material. The significant part of upper shelf energy is attributed to the energy for the plastic deformation zone near V-notch in the Charpy specimen. To preserve the absorbed energy, the anticipated plastically deformed zone shall not be affected by the reconstitution procedure. In order to clarify the condition for preserving the absorbed energy in the case of reconstitution, the preliminary data has been obtained using un-irradiated and irradiated Charpy specimens, and the following results have been obtained by the tests carried out in this research. 1) The plastic deformation widths have been estimated by measuring the hardness distribution near the V-notch of the un-irradiated Charpy impact tested specimens, correlated to the absorbed energy. 2) The absorbed energy shifts of reconstituted, un-irradiated Charpy specimens with various length of the specimen

  8. Proceedings of a C.S.N.I. specialist meeting on instrumented pre-cracked Charpy testing

    International Nuclear Information System (INIS)

    This report presents the status of the testing and data analysis procedures for the instrumented pre-cracked Charpy test with emphasis on the application of the test technique to the nuclear industry. The report (Proceedings) consist of invited technical papers by specialists in the field and a synopsis of the comments, conclusions, and recommendations reached in a workshop session. The CSNl-sponsored and EPRI-hosted meeting confirmed both the popularity of the test technique in the nuclear industry and the problems associated with the test technique due to the lack of a national or international consensus standard. Major emphasis in the meeting was devoted to evaluating the existing industry testing procedure (EPRI procedure) and proposed national standards (ASTM, ASK). The EPRI procedures were considered adequate by specialists concerned with engineering applications, but too restrictive by specialists concerned with research applications. As a result of the conference, a compilation of state-of-the-art papers is now available to code and standard committees. Specific comments concerning test and data analysis procedures, applications in the nuclear industry, and future research areas are also contained in the proceedings

  9. Comparison of microstructural properties and Charpy impact behaviour between different plates of the Eurofer97 steel and effect of isothermal ageing

    Energy Technology Data Exchange (ETDEWEB)

    Stratil, Ludek [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno (Czech Republic); Hadraba, Hynek, E-mail: hadraba@ipm.cz [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno (Czech Republic); Bursik, Jiri; Dlouhy, Ivo [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno (Czech Republic)

    2011-09-30

    Highlights: > Two plates of Eurofer97 steel were tested in thermally unaffected and aged state. > The two plates of Eurofer97 differ significantly in mean prior austenite grain size. > The different grain size lead to different transition temperature between the plates. > Thermal ageing applied lead to slight microstructural changes of the Eurofer97. > The microstructural changes caused small shift of transition temperature. - Abstract: The microstructure and fracture properties of the Eurofer97 steel plates of thickness 14 mm and 25 mm were investigated in as-received state and in state after long-term thermal ageing (550 deg. C/5000 h). Detailed microstructure studies were carried out by means of optical light, electron and quantitative electron microscopy. Mechanical properties were evaluated by means of Charpy impact testing and hardness testing and fracture surfaces were fractographically analysed in macro and microscales. The microstructure of the Eurofer97 consisted of tempered martensite with M{sub 23}C{sub 6} and MX precipitates. Microstructure of 14 mm plate was more homogenous and fine grained than 25 mm plate. Due to different microstructure the t{sub DBTT} of thicker plate was on +10 deg. C higher than for 14 mm plate for which reached -60 deg. C. Slight microstructural changes on the level of subgrain consisting of their partial recrystallization and slight carbide coarsening were observed after applied ageing. The isothermal ageing caused evident shift in t{sub DBTT} about +5 deg. C, which was most likely caused by recrystallization of subgrains.

  10. Effects of Microstructural Inhomogeneity on Charpy Impact Properties for Reactor Pressure Vessel

    International Nuclear Information System (INIS)

    Reactor pressure vessel (RPV) steels are fabricated by vacuum carbon deoxidation (VCD), and then heat treatment of quenching and tempering is conducted after forging. The through-the-thickness variation of microstructure in RPV can occur due to the cooling rate gradient during quenching and inhomogeneous deformation during forging process. The variation of microstructure in RPV affects the mechanical properties, and inhomogeneity in mechanical properties can occur. The evaluation of mechanical properties of RPV is conducted at thickness of 1/4T. In order to evaluate the safety of RPV more correctly, the research about the through-the-thickness variation of microstructure and mechanical properties in RPV is need. 1. The fine low bainite (LB) is the dominant phase at the inner-surface (0T), but coarse upper bainite (UB) is the dominant phase at the center (1/2T). This is because cooling rate gradient from surface to center occurs during quenching. 2. Inter-lath carbides act as fracture initiation site, and it reduces impact toughness. 3. The upper shelf energy is low and the reference temperatures are high at the 1/4T. Impact properties are poor at 1/4T because of the formation of coarse upper bainite structure and coarse inter-lath carbides

  11. Effects of Microstructural Inhomogeneity on Charpy Impact Properties for Reactor Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seokmin; Song, Jaemin; Kim, Min-Chul; Choi, Kwon-Jae; Lee, Bong-Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Reactor pressure vessel (RPV) steels are fabricated by vacuum carbon deoxidation (VCD), and then heat treatment of quenching and tempering is conducted after forging. The through-the-thickness variation of microstructure in RPV can occur due to the cooling rate gradient during quenching and inhomogeneous deformation during forging process. The variation of microstructure in RPV affects the mechanical properties, and inhomogeneity in mechanical properties can occur. The evaluation of mechanical properties of RPV is conducted at thickness of 1/4T. In order to evaluate the safety of RPV more correctly, the research about the through-the-thickness variation of microstructure and mechanical properties in RPV is need. 1. The fine low bainite (LB) is the dominant phase at the inner-surface (0T), but coarse upper bainite (UB) is the dominant phase at the center (1/2T). This is because cooling rate gradient from surface to center occurs during quenching. 2. Inter-lath carbides act as fracture initiation site, and it reduces impact toughness. 3. The upper shelf energy is low and the reference temperatures are high at the 1/4T. Impact properties are poor at 1/4T because of the formation of coarse upper bainite structure and coarse inter-lath carbides.

  12. Definition of the minimum longitude of insert in the rebuilding of Charpy test tubes for surveillance and life extension of vessels in Mexico

    International Nuclear Information System (INIS)

    In the National Institute of Nuclear Research (Mexico) a welding system for the rebuilding of Charpy test tubes has been developed, automated, qualified and used for the surveillance of the mechanical properties (mainly embrittlement) of the vessel. This system uses the halves of the rehearsed Charpy test tubes of the surveillance capsules extracted of the reactors, to obtain, of a rehearsed test tube, two reconstituted test tubes. This rebuilding process is used so much in the surveillance program like in the potential extension of the operation license of the vessel. To the halves of Charpy test tubes that have been removed the deformed part by machine are called -insert- and in a very general way the rebuilding consists in weld with the welding process -Stud Welding- two metallic implants in the ends of the insert, to obtain a reconstituted test tube. The main characteristic of this welding are the achieved small dimensions, so much of the areas welded as of the areas affected by the heat. The applicable normative settles down that the minim longitude of the insert for the welding process by Stud Welding it should be of 18 mm, however according to the same normative this longitude can diminish if is demonstrated analytic or experimentally that the central volume of 1 cm3 in the insert is not affected. In this work the measurement of the temperature profiles to different distances of the welding interface is presented, defining an equation for the maximum temperatures reached in function of the distance, on the other hand the real longitude affected in the test tube by means of metallography is determined and this way the minimum longitude of the insert for this developed rebuilding system was determined. (Author)

  13. Numerical simulation of a Charpy test and correlation of fracture toughness with fracture energy. Vessel steel and duplex stainless steel of the primary loop

    International Nuclear Information System (INIS)

    The analysis methods used to evaluate the harmlessness of defects in the components of the primary coolant circuit of pressurized water reactor are based on the knowledge of the failure properties of concerned materials. The toughness is used to be measured through tests performed on normalized samples. But in some cases, especially for the vessel steel submitted to irradiation effects or for cast components in duplex stainless steel sensitive to thermal ageing, these measurements are not available on the material aged in operation. Therefore, fracture resistance has been evaluated through Charpy tests. Toughness is thus obtained on the basis of an empirical correlation. To improve these predictions, a modeling of the Charpy test in the framework of the local approach to fracture has been performed, for both materials. For the vessel steel, a complete evaluation of toughness has been achieved on the basis of a bidimensional viscoplastic modeling under large strain assumptions and a post-treatment with a Weibull model (cleavage fracture). The main hypothesis (partition between plain stress and plain strain areas in the bidimensional modeling) was corrected after a three dimensional calculations with the finite element program Code-Aster. The fracture analysis put into evidence that damage considerations like cavity nucleation and growth have to be introduced in the model in order to improve the description of physical phenomena. Two ways of progress have been suggested and are in course of being investigated, one in the framework of local approach to failure, the other with the help of micro-macro relationship. With regard to the duplex steel, the description of a Charpy (U) test allowed to clearly discriminate between crack initiation and propagation phases. A modeling through an equivalent homogenous material with a damage law based on a modified Gurson potential enables to describe quantitatively both phases of fracture. It clearly appears that a reliable

  14. Effects of Cooling Conditions on Microstructure, Tensile Properties, and Charpy Impact Toughness of Low-Carbon High-Strength Bainitic Steels

    Science.gov (United States)

    Sung, Hyo Kyung; Shin, Sang Yong; Hwang, Byoungchul; Lee, Chang Gil; Lee, Sunghak

    2013-01-01

    In this study, four low-carbon high-strength bainitic steel specimens were fabricated by varying finish cooling temperatures and cooling rates, and their tensile and Charpy impact properties were investigated. All the bainitic steel specimens consisted of acicular ferrite, granular bainite, bainitic ferrite, and martensite-austenite constituents. The specimens fabricated with higher finish cooling temperature had a lower volume fraction of martensite-austenite constituent than the specimens fabricated with lower finish cooling temperature. The fast-cooled specimens had twice the volume fraction of bainitic ferrite and consequently higher yield and tensile strengths than the slow-cooled specimens. The energy transition temperature tended to increase with increasing effective grain size or with increasing volume fraction of granular bainite. The fast-cooled specimen fabricated with high finish cooling temperature and fast cooling rate showed the lowest energy transition temperature among the four specimens because of the lowest content of coarse granular bainite. These findings indicated that Charpy impact properties as well as strength could be improved by suppressing the formation of granular bainite, despite the presence of some hard microstructural constituents such as bainitic ferrite and martensite-austenite.

  15. Standard test method for instrumented impact testing of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This standard establishes the requirements for performing instrumented Charpy V-Notch (CVN) and instrumented Miniaturized Charpy V-Notch (MCVN) impact tests on metallic materials. This method, which is based on experience developed testing steels, provides further information (in addition to the total absorbed energy) on the fracture behavior of the tested materials. Minimum requirements are given for measurement and recording equipment such that similar sensitivity and comparable total absorbed energy measurements to those obtained in Test Methods E 23 and E 2248 are achieved. 1.2 The values stated in SI units are to be regarded as the standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Tensile and Charpy impact properties of an ODS ferritic/martensitic steel 9Cr–1.8W–0.5Ti–0.35Y2O3

    International Nuclear Information System (INIS)

    Highlights: • The tensile property and Charpy impact were tested. • Both strength and plasticity in LT direction are better than that of TL direction. • The LSE was more than 65% of the USE from absorbed energy curve. • The initiation and propagation energy at different temperatures were calculated. • High LSE and dimples on the fracture surface indicated good toughness at −60 °C. - Abstract: A 9Cr-ODS ferritic/martensitic steel with a composition of 9Cr–1.8W–0.5Ti–0.35Y2O3 was fabricated by mechanical alloying and hot isostatic pressing, followed by hot rolling. Tensile properties were measured at room temperature (23 °C) and 700 °C in the rolling direction (LT) and the transverse direction (TL). The ultimate tensile strength (UTS) of the as-rolled samples in both directions reached 990 MPa at 23 °C, and still maintained at 260 MPa at 700 °C. The tensile strength and elongation of the rolling direction was greater than that of the transverse direction. The Charpy impact was tested from −100 to 100 °C in the LT direction. The lower shelf energy (LSE) was more than 65% of the upper shelf energy (USE). The total absorbed energy was separated into the energies for crack initiation and propagation. The propagation energy was always higher than the initiation energy in the range of temperatures tested. The ductile-to-brittle transition temperature (DBTT) of the rolled 9Cr ODS evaluated by an absorbed energy curve was about 0 °C. However, the high LSE and the fracture surface that still contained dimples at lower shelf indicated good toughness of the as-rolled 9Cr ODS steels at temperature of −60 °C

  17. Tensile and Charpy impact properties of an ODS ferritic/martensitic steel 9Cr–1.8W–0.5Ti–0.35Y{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guangming; Zhou, Zhangjian, E-mail: zhouzhj@mater.ustb.edu.cn; Wang, Man; Li, Shaofu; Zou, Lei; Zhang, Liwei

    2014-04-15

    Highlights: • The tensile property and Charpy impact were tested. • Both strength and plasticity in LT direction are better than that of TL direction. • The LSE was more than 65% of the USE from absorbed energy curve. • The initiation and propagation energy at different temperatures were calculated. • High LSE and dimples on the fracture surface indicated good toughness at −60 °C. - Abstract: A 9Cr-ODS ferritic/martensitic steel with a composition of 9Cr–1.8W–0.5Ti–0.35Y{sub 2}O{sub 3} was fabricated by mechanical alloying and hot isostatic pressing, followed by hot rolling. Tensile properties were measured at room temperature (23 °C) and 700 °C in the rolling direction (LT) and the transverse direction (TL). The ultimate tensile strength (UTS) of the as-rolled samples in both directions reached 990 MPa at 23 °C, and still maintained at 260 MPa at 700 °C. The tensile strength and elongation of the rolling direction was greater than that of the transverse direction. The Charpy impact was tested from −100 to 100 °C in the LT direction. The lower shelf energy (LSE) was more than 65% of the upper shelf energy (USE). The total absorbed energy was separated into the energies for crack initiation and propagation. The propagation energy was always higher than the initiation energy in the range of temperatures tested. The ductile-to-brittle transition temperature (DBTT) of the rolled 9Cr ODS evaluated by an absorbed energy curve was about 0 °C. However, the high LSE and the fracture surface that still contained dimples at lower shelf indicated good toughness of the as-rolled 9Cr ODS steels at temperature of −60 °C.

  18. Failure mechanics of fiber composite notched charpy specimens. [stress analysis

    Science.gov (United States)

    Chamis, C. C.

    1976-01-01

    A finite element stress analysis was performed to determine the stress variation in the vicinity of the notch and far field of fiber composites Charpy specimens (ASTM Standard). NASTRAN was used for the finite element analysis assuming linear behavior and equivalent static load. The unidirectional composites investigated ranged from Thornel 75 Epoxy to S-Glass/Epoxy with the fiber direction parallel to the long dimension of the specimen. The results indicate a biaxial stress state exists in (1) the notch vicinity which is dominated by transverse tensile and interlaminar shear and (2) near the load application point which is dominated by transverse compression and interlaminar shear. The results also lead to the postulation of hypotheses for the predominant failure modes, the fracture initiation, and the fracture process. Finally, the results indicate that the notched Charpy test specimen is not suitable for assessing the impact resistance of nonmetallic fiber composites directly.

  19. Charpy V, an application in Mat lab

    International Nuclear Information System (INIS)

    The obtained results with the system Charpy VV1 designed in Mat lab for the estimate of parameters of three mathematical models are shown. The adjustment of data is used to determine the fracture energy, the lateral expansion and the percentage of ductility of steels coming from the reactor vessels of Laguna Verde, Veracruz. The data come from test tubes type Charpy V of irradiated material and not irradiated. To verify our results they were compared with those obtained by General Electric of data coming from the Laguna Verde nuclear power plant. (Author)

  20. Estimation of Charpy notch toughness for thermal aging specimens of cast duplex stainless steel using thermalelectric power measurement

    International Nuclear Information System (INIS)

    The material properties of cast duplex stainless steel, which is used for main coolant pipes of PWR (pressurized water reactor) type nuclear power plants, change due to thermal aging. Therefore it is advisable to evaluate these changes of material properties non-destructively for maintenance of the plant component. In order to establish a non-destructive evaluation procedure for the degree of thermal aging of cast duplex stainless steel, thermoelectric power (TEP) measurements were carried out with a newly made TEP meter for thermal aging specimens, with different ferrite contents, aging temperatures and aging periods. Then the relationship between TEP and notch toughness obtained by Charpy impact test was investigated. As the results: (1) TEP increases due to thermal aging. The higher ferrite content, the higher TEP. The higher aging temperature, the more rapidly TEP increases. (2) Because of the decrease of Charpy notch toughness and the increase of TEP due to the fluctuation of Cr concentration caused by the phase separation of the ferrite phase, TEP increases by thermal aging as the Charpy notch toughness decreases. (3) Regardless of the aging temperature, the specimens with the same ferrite content have the same relationship between Charpy notch toughness and TEP. (4) It is possible to estimate Charpy notch toughness with an error of 100 J/cm2 by TEP in the beginning of aging. Therefore, it can be concluded that we can estimate Charpy notch toughness for cast duplex stainless steel by TEP depending on the ferrite content regardless of the aging temperature. (author)

  1. Instrumented impact testing machine with reduced specimen oscillation effects

    International Nuclear Information System (INIS)

    Owing to small and inexpensive specimens the Charpy impact test is widely used in quality control and alloy development. Limitations in power reactor survellance capsules it is also widely used for safety analysis purposes. Instrumenting the tup and computerizing data acquisition, makes dynamic fracture mechanics data measurement possible and convenient. However, the dynamic effects (inertia forces, specimen oscillations) in the impact test cause inaccuracies in the recorded load-time diagram and hence diminish the reliability of the calculated dynamic fracture mechanics parameters. To decrease inaccuracies a new pendulum type of instrumented impact test apparatus has been developed and constructed in the Metals Laboratory of the Technical Research Centre of Finland. This tester is based on a new principle involving inverted test geometry. The purpose of the geometry inversion is to reduce inertia load and specimen oscillation effects. Further, the new impact tester has some other novel features: e.g. the available initia impact energy is about double compared to the conventional standard (300 J) impact tester allowing the use of larger (10 x 20 x 110 mm) bend specimens than normal Charpy specimens. Also, the rotation asix in the three point bending is nearly stationary making COD-measurements possible. An experimental test series is described in which the inertia effects and specimen oscillations are compared in the conventional and new impact tester utilizing Charpy V-notch specimens. Comparison of the two test geometries is also made with the aid of an analytical model using finite element method (FEM) analysis. (author)

  2. Definition of the minimum longitude of insert in the rebuilding of Charpy test tubes for surveillance and life extension of vessels in Mexico; Definicion de la longitud minima de inserto en la reconstitucion de probetas Charpy para vigilancia y extension de vida de vasijas en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Romero C, J.; Hernandez C, R.; Rocamontes A, M., E-mail: jesus.romero@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    In the National Institute of Nuclear Research (Mexico) a welding system for the rebuilding of Charpy test tubes has been developed, automated, qualified and used for the surveillance of the mechanical properties (mainly embrittlement) of the vessel. This system uses the halves of the rehearsed Charpy test tubes of the surveillance capsules extracted of the reactors, to obtain, of a rehearsed test tube, two reconstituted test tubes. This rebuilding process is used so much in the surveillance program like in the potential extension of the operation license of the vessel. To the halves of Charpy test tubes that have been removed the deformed part by machine are called -insert- and in a very general way the rebuilding consists in weld with the welding process -Stud Welding- two metallic implants in the ends of the insert, to obtain a reconstituted test tube. The main characteristic of this welding are the achieved small dimensions, so much of the areas welded as of the areas affected by the heat. The applicable normative settles down that the minim longitude of the insert for the welding process by Stud Welding it should be of 18 mm, however according to the same normative this longitude can diminish if is demonstrated analytic or experimentally that the central volume of 1 cm{sup 3} in the insert is not affected. In this work the measurement of the temperature profiles to different distances of the welding interface is presented, defining an equation for the maximum temperatures reached in function of the distance, on the other hand the real longitude affected in the test tube by means of metallography is determined and this way the minimum longitude of the insert for this developed rebuilding system was determined. (Author)

  3. Standard test methods for notched bar impact testing of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 These test methods describe notched-bar impact testing of metallic materials by the Charpy (simple-beam) test and the Izod (cantilever-beam) test. They give the requirements for: test specimens, test procedures, test reports, test machines (see Annex A1) verifying Charpy impact machines (see Annex A2), optional test specimen configurations (see Annex A3), precracking Charpy V-notch specimens (see Annex A4), designation of test specimen orientation (see Annex A5), and determining the percent of shear fracture on the surface of broken impact specimens (see Annex A6). In addition, information is provided on the significance of notched-bar impact testing (see Appendix X2), methods of measuring the center of strike (see Appendix X2). 1.2 These test methods do not address the problems associated with impact testing at temperatures below -196 C (-320 F, 77 K). 1.3 The values stated in SI units are to be regarded as the standard. Inch-pound units are provided for information only. This standard does not purpor...

  4. Numerical modelling of Charpy-V notch test by local approach to fracture. Application to an A508 steel in the ductile-brittle transition range; Modelisation de l'essai Charpy par l'approche locale de la rupture. Application au cas de l'acier 16MND5 dans le domaine de transition

    Energy Technology Data Exchange (ETDEWEB)

    Tanguy, B

    2001-07-15

    Ferritic steels present a transition of the rupture mode which goes progressively of a brittle rupture (cleavage) to a ductile rupture when the temperature increases. The following of the difference of the transition temperature of the PWR vessel steel by the establishment of toughness curves makes of the Charpy test an integrating part of the monitoring of the French PWR reactors. In spite of the advantages which are adapted to it in particular its cost, the Charpy test does not allow to obtain directly a variable which characterizes a crack propagation resistance as for instance the toughness used for qualifying the mechanical integrity of a structure. This work deals with the establishment of the through impact strength-toughness in the transition range of the vessel steel: 16MND5 from a non-empirical approach based on the local approach of the rupture. The brittle rupture is described by the Beremin model (1983), which allows to describe the dispersion inherent in this rupture mode. The description of the brittle fissure is carried out by the GTN model (1984) and by the Rousselier model (1986). This last model has been modified in order to obtain a realistic description of the brittle damage in the case of fast solicitations and of local heating. The method proposed to determine the parameters of the damage models depends only of tests on notched specimens and of the inclusion data of the material. The behaviour is described by an original formulation parametrized in temperature which allows to describe all the tests carried out in this study. Before using this methodology, an experimental study of the behaviour and of the rupture modes of the steel 16MND5 has been carried out. From the toughness tests carried out in quasi-static and dynamical conditions, it has been revealed that this steel does not present important unwedging of its toughness curve due to the velocity effect. In the transition range, local heating of about 150 C have been measured in the root

  5. Transverse and z-Direction CVN Impact Tests of X65 Line Pipe Steels of Two Centerline Segregation Ratings

    Science.gov (United States)

    Su, Lihong; Li, Huijun; Lu, Cheng; Li, Jintao; Fletcher, Leigh; Simpson, Ian; Barbaro, Frank; Zheng, Lei; Bai, Mingzhuo; Shen, Jianlan; Qu, Xianyong

    2016-08-01

    Centerline segregation occurs as a positive concentration of alloying elements in the mid-thickness region of continuously cast slab. Depending upon its severity, it may affect mechanical properties and potentially downstream processing such as weldability, particularly for high-strength line pipe. The segregation fraction in continuously cast slabs and corresponding hot-rolled strips was assessed on API 5L grade X65 line pipe steels with different levels of segregation, rated as Mannesmann 2.0 and 1.4. The results showed that the segregation fraction in hot-rolled strip samples was in accordance with that assessed in the cast slabs, and the segregated regions in hot-rolled strip samples were found to be discontinuous. Transverse and z-direction CVN impact tests were conducted on the two strips and the results showed that centerline segregation does have an influence on the Charpy impact properties of line pipe steel. Specimens located at segregated regions exhibited lower Charpy impact toughness and strips rolled from slabs with higher segregation levels are more likely to exhibit greater variability in Charpy impact toughness. The influence of centerline segregation on z-direction Charpy impact toughness is more severe than on transverse Charpy impact toughness. Lower Charpy impact toughness and brittle fracture surface with cleavage facets along with rod-shaped MnS inclusions were observed for the strip rolled from slab with 2.0 segregation rating if the Charpy specimens were located at segregated regions. The influence on Charpy impact toughness can be associated with the pearlite structure at the centerline and level of MnS inclusions.

  6. Transverse and z-Direction CVN Impact Tests of X65 Line Pipe Steels of Two Centerline Segregation Ratings

    Science.gov (United States)

    Su, Lihong; Li, Huijun; Lu, Cheng; Li, Jintao; Fletcher, Leigh; Simpson, Ian; Barbaro, Frank; Zheng, Lei; Bai, Mingzhuo; Shen, Jianlan; Qu, Xianyong

    2016-06-01

    Centerline segregation occurs as a positive concentration of alloying elements in the mid-thickness region of continuously cast slab. Depending upon its severity, it may affect mechanical properties and potentially downstream processing such as weldability, particularly for high-strength line pipe. The segregation fraction in continuously cast slabs and corresponding hot-rolled strips was assessed on API 5L grade X65 line pipe steels with different levels of segregation, rated as Mannesmann 2.0 and 1.4. The results showed that the segregation fraction in hot-rolled strip samples was in accordance with that assessed in the cast slabs, and the segregated regions in hot-rolled strip samples were found to be discontinuous. Transverse and z-direction CVN impact tests were conducted on the two strips and the results showed that centerline segregation does have an influence on the Charpy impact properties of line pipe steel. Specimens located at segregated regions exhibited lower Charpy impact toughness and strips rolled from slabs with higher segregation levels are more likely to exhibit greater variability in Charpy impact toughness. The influence of centerline segregation on z-direction Charpy impact toughness is more severe than on transverse Charpy impact toughness. Lower Charpy impact toughness and brittle fracture surface with cleavage facets along with rod-shaped MnS inclusions were observed for the strip rolled from slab with 2.0 segregation rating if the Charpy specimens were located at segregated regions. The influence on Charpy impact toughness can be associated with the pearlite structure at the centerline and level of MnS inclusions.

  7. Charpy V, an application in Mat lab; Charpy V, una aplicacion en Matlab

    Energy Technology Data Exchange (ETDEWEB)

    Castillo M, J.A.; Torres V, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    The obtained results with the system Charpy V{sub V}1 designed in Mat lab for the estimate of parameters of three mathematical models are shown. The adjustment of data is used to determine the fracture energy, the lateral expansion and the percentage of ductility of steels coming from the reactor vessels of Laguna Verde, Veracruz. The data come from test tubes type Charpy V of irradiated material and not irradiated. To verify our results they were compared with those obtained by General Electric of data coming from the Laguna Verde nuclear power plant. (Author)

  8. Assessment of Ductile-to-Brittle Transition Behavior of Localized Microstructural Regions in a Friction-Stir Welded X80 Pipeline Steel with Miniaturized Charpy V-Notch Testing

    Science.gov (United States)

    Avila, Julian A.; Lucon, Enrico; Sowards, Jeffrey; Mei, Paulo Roberto; Ramirez, Antonio J.

    2016-06-01

    Friction-stir welding (FSW) is an alternative welding process for pipelines. This technology offers sound welds, good repeatability, and excellent mechanical properties. However, it is of paramount importance to determine the toughness of the welds at low temperatures in order to establish the limits of this technology. Ductile-to-brittle transition curves were generated in the present study by using a small-scale instrumented Charpy machine and miniaturized V-notch specimens (Kleinstprobe, KLST); notches were located in base metal, heat-affected, stirred, and hard zones within a FSW joint of API-5L X80 Pipeline Steel. Specimens were tested at temperatures between 77 K (-196 °C) and 298 K (25 °C). Based on the results obtained, the transition temperatures for the base material and heat-affected zone were below 173 K (-100 °C); conversely, for the stirred and hard zones, it was located around 213 K (-60 °C). Fracture surfaces were characterized and showed a ductile fracture mechanism at high impact energies and a mixture of ductile and brittle mechanisms at low impact energies.

  9. Development of dissimilar welding technique between PNC-FMS wrapper tube and SUS316 steel. 1. Investigation of δ ferrite formation and evaluation of Charpy impact property

    International Nuclear Information System (INIS)

    Ferritic/Martensitic steel (PNC-FMS) with superior resistance to swelling is being developed as wrapper tube for the long-life core of large-scale fast breeder reactor. If the δ ferrite phase would be formed at heat affected zone (HAZ) in welding between PNC-FMS wrapper tube and SUS316 steel, and thus toughness degradation would be suspected due to δ ferrite formation. In this study, the formation of the δ ferrite in applying TIG welding and EB welding are investigated using base metal of 3 types, which are Nieq max./Creq min., Nieq min./Creq max. and the center of chemical composition in the specification. The effect of the amount of the δ ferrite formation and characteristics of toughness change with thermal aging were evaluated. The results are summarized as follows. 1. The δ ferrite generation can be suppressed in the combination of welding process and chemical composition. (1) In case of specification center, the δ ferrite formation can be suppressed about 1% by EB welding. (2) In case of Nieq max./Creq min. in the specification, the δ ferrite formation can be perfectly suppressed even in TIG welding or EB welding. 2. The relationship between δ ferrite content and Charpy impact value was investigated using 3 types of chemical composition in the specification. (1) Ductile Brittle Transition Temperature (DBTT) increased, when δ ferrite content increases. (2) DBTT shift by aging is within about 23degC. (3) DBTT is influenced by grain size and it is lower as the fine grain (grain no.11). (4) Upper Shelf Energy (USE) is not dependent on the δ ferrite content. (author)

  10. A study on the structural integrity evaluation of the dual purpose casks for the spent fuel storage and transport with HANARO irradiation impact tests

    International Nuclear Information System (INIS)

    This study is conducted in order to evaluate structural integrity of the dual propose casks for the spent fuel storage and transport after 30 years storage. Charpy impact specimen was manufactured and material irradiation test was performed using the HANARO. For the irradiated and unirradiated Charpy impact specimen with v-notch, the impact test was conducted, then the impact test results were applied in the impact analysis of the dual propose casks for the spent fuel storage and transport. From the impact analysis results, we confirmed that the structural integrity of the dual propose cask was maintained under original and irradiation conditions

  11. Influence of Striking Edge Radius (2 mm versus 8 mm) on Instrumented Charpy Data and Absorbed Energies

    International Nuclear Information System (INIS)

    The most commonly used test standards for performing Charpy impact tests (ISO 148 and ASTM E 23) envisage the use of strikers having different radii of the striking edge, i.e. 2 mm (ISO) and 8 mm (ASTM). The effect of striker geometry on Charpy results was extensively studied in the past in terms of absorbed energy measured by the machine encoder, but few investigations are available on the influence of striker configuration on the results of instrumented Charpy tests (characteristic forces, displacements and integrated energy). In this paper, these effects are investigated based on the analysis of published results from three interlaboratory studies and some unpublished Charpy data obtained at SCK-CEN. The instrumented variables which are the most sensitive to the radius of the striking edge are the maximum force and its corresponding displacement, with 8mm-strikers providing systematically higher values. Absorbed energies, obtained both from the instrumented trace and from the pendulum encoder, are almost insensitive to the type of striker up to 200 J. For higher energy levels, the values obtained from 8mm strikers become progressively larger. Data scatter is generally higher for 2mm-strikers.

  12. Influence of Striking Edge Radius (2 mm versus 8 mm) on Instrumented Charpy Data and Absorbed Energies

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.

    2008-08-15

    The most commonly used test standards for performing Charpy impact tests (ISO 148 and ASTM E 23) envisage the use of strikers having different radii of the striking edge, i.e. 2 mm (ISO) and 8 mm (ASTM). The effect of striker geometry on Charpy results was extensively studied in the past in terms of absorbed energy measured by the machine encoder, but few investigations are available on the influence of striker configuration on the results of instrumented Charpy tests (characteristic forces, displacements and integrated energy). In this paper, these effects are investigated based on the analysis of published results from three interlaboratory studies and some unpublished Charpy data obtained at SCK-CEN. The instrumented variables which are the most sensitive to the radius of the striking edge are the maximum force and its corresponding displacement, with 8mm-strikers providing systematically higher values. Absorbed energies, obtained both from the instrumented trace and from the pendulum encoder, are almost insensitive to the type of striker up to 200 J. For higher energy levels, the values obtained from 8mm strikers become progressively larger. Data scatter is generally higher for 2mm-strikers.

  13. Electron beam welding reconstitution technology of Charpy-V specimens

    International Nuclear Information System (INIS)

    This paper reports results connected with the reconstitution of the Cv-type specimens by electron beam welding technology. The experiments were carried out using a 15 kW Leybold Heraus welding unit in a range of power between 1.5 and 3.5 kW, and welding speed from 0.5cm/s to 1.5 cm/s. Material which used in this study is 15Kh2NMFA reactor pressure vessel steel. Weldability of pressure vessel steel by electron beam was investigated in accordance EN ISO 13919-1 1996. Charpy impact tests show good agreement between original and electron beam reconstituted specimens. (author)

  14. Comparison of transition temperature criteria applied for KLST and ISO-V type Charpy specimens

    International Nuclear Information System (INIS)

    A great deal of test data have been obtained on reactor pressure vessel steels using the standard Charpy-V test. Although more advanced test methods, based on elastic-plastic fracture mechanics, are both recommendable and already in use in the surveillance programmes of some nuclear power plants (NPPs), Charpy tests are still required, e.g., by regulatory guides. Besides the normal-size (ISO-V) Charpy specimen (10 x10 x 55 mm3), various types of sub-size specimens have been introduced. One standardised sub-size specimen being in use is the so-called KLST specimen, the size of which is 3 x 4 x 27 mm3 with 1 mm central notch (DIN50 115). So far the test data published for the KLST specimen, as well as sub-size specimens in general, is still limited. The results from small specimen testing are typically used for evaluating the fracture behaviour of the ISO-V Charpy specimen and if there are no test results available for the correlation, as there usually is not, a general correlation has to be applied to evaluate the fracture behaviour of the ISO-V specimen. The availability of a sub-size specimen depends therefore significantly on how reliably this relationship has been established. Impact test data measured with different specimens have been correlated using some appropriate criterion (or criteria) and since a total transition curve is normally measured, there are several ones available. The criterion can be a fixed energy or lateral expansion level describing the transition temperature or the level can be derived from the upper-shelf energy (USE). In general, the proposed criterion can be divided into two groups: those derived from the dimensions of the specimens and those derived empirically from experimental data. Test data measured with ISO-V and KLST-type Charpy specimens are discussed and the validity of two proposed, basically different transition temperature criteria and the resulting differences in the temperatures, that are inevitable because of the

  15. On the Effectiveness of the Dynamic Force Adjustment for Reducing the Scatter of Instrumented Charpy Results

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.

    2008-09-15

    One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. An interesting alternative to the conventional static calibration recommended by the standards is the Dynamic Force Adjustment (DFA), in which forces and displacements are iteratively adjusted until equality is achieved between absorbed energies calculated under the test record (Wt) and measured by the machine encoder (KV). In this study, this procedure has been applied to the instrumented data obtained by 10 international laboratories using notched and precracked Charpy specimens, in the framework of a Coordinated Research Project (CRP8) of IAEA. DFA is extremely effective in reducing the between-laboratory scatter for both general yield and maximum forces. The effect is less significant for dynamic reference temperatures measured from precracked Charpy specimens using the Master Curve procedure, but a moderate reduction of the standard deviation is anyway observed. It is shown that striker calibration is a prominent contribution to the interlaboratory variability of instrumented impact forces, particularly in the case of maximum forces.

  16. Testing of materials and scale models for impact limiters

    International Nuclear Information System (INIS)

    Aluminum Honeycomb and Polyurethane foam specimens were tested to obtain experimental data on the material's behavior under different loading conditions. This paper reports the dynamic tests conducted on the materials and on the design and testing of scale models made out of these open-quotes Impact Limiters,close quotes as they are used in the design of transportation casks. Dynamic tests were conducted on a modified Charpy Impact machine with associated instrumentation, and compared with static test results. A scale model testing setup was designed and used for preliminary tests on models being used by current designers of transportation casks. The paper presents preliminary results of the program. Additional information will be available and reported at the time of presentation of the paper

  17. Correlations between Standard and Miniaturised Charpy-V Specimens

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.; Van Walle, E.; Fabry, A.; Puzzolante, J.-L.; Verstrepen, A.; Vosch, R.; Van de Velde, L

    1998-12-01

    A total of 565 instrumented impact tests (232 performed on full-size and 333 on sub-size Charpy-V specimens) have been analysed in order to derive meaningful assumptions on the correlations existing between test results obtained on specimens of different size. Nine materials (pressure vessel steels) have been considered, in both as-received and irradiated state, for a total of 19 conditions examined. For the analysis of data, conventional as well novel approaches have been investigated; former ones, based on a review of the existing literature, include predictions of USE values by the use of normalization factors (NF), shifts of index temperatures related to energy/lateral expansion/shear fracture levels, and a combination of both approaches (scaling and shifting of energy curves). More original and recent proposals have also been verified, available in the literature but also proposed by SCK-CEN in the frame of enhanced surveillance of nuclear reactor pressure vessels. Conclusions have been drawn regarding the applicability and reliability of these methodologies, and recommendations have been given for future developments of the activities on this topic.

  18. Correlations between Standard and Miniaturised Charpy-V Specimens

    International Nuclear Information System (INIS)

    A total of 565 instrumented impact tests (232 performed on full-size and 333 on sub-size Charpy-V specimens) have been analysed in order to derive meaningful assumptions on the correlations existing between test results obtained on specimens of different size. Nine materials (pressure vessel steels) have been considered, in both as-received and irradiated state, for a total of 19 conditions examined. For the analysis of data, conventional as well novel approaches have been investigated; former ones, based on a review of the existing literature, include predictions of USE values by the use of normalization factors (NF), shifts of index temperatures related to energy/lateral expansion/shear fracture levels, and a combination of both approaches (scaling and shifting of energy curves). More original and recent proposals have also been verified, available in the literature but also proposed by SCK-CEN in the frame of enhanced surveillance of nuclear reactor pressure vessels. Conclusions have been drawn regarding the applicability and reliability of these methodologies, and recommendations have been given for future developments of the activities on this topic

  19. Fractographic examination of reduced activation ferritic/martensitic steel charpy specimens irradiated to 30 dpa at 370{degrees}C

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.; Hamilton, M.L. [Pacific Northwest National Lab., Richland, WA (United States); Schubert, L.E. [Univ. of Missouri, Rolla, MO (United States)

    1996-10-01

    Fractographic examinations are reported for a series of reduced activation ferritic/Martensitic steel Charpy impact specimens tested following irradiation to 30 dpa at 370{degrees}C in FFTF. One-third size specimens of six low activation steels developed for potential application as structural materials in fusion reactors were examined. A shift in brittle fracture appearance from cleavage to grain boundary failure was noted with increasing manganese content. The results are interpreted in light of transmutation induced composition changes in a fusion environment.

  20. The Gurson-Tvergaard-Needleman model calibration from sub-size test specimens by size corresponding to the half of Charpy specimen

    Czech Academy of Sciences Publication Activity Database

    Stratil, Luděk; Šiška, Filip; Hadraba, Hynek; Dlouhý, Ivo

    Ostrava : Ocelot s.r.o, 2014 - (Matocha, K.; Hurst, R.; Sun, W.), s. 368-381 ISBN 978-80-260-6722-1. [SSTT 2014 - International Conference Determination of Mechanical Properties of Materials by Small Punch and Other Miniature Testing Techniques /3./. Seggau (AT), 23.09.2014-25.09.2014] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA MŠk EE2.3.20.0197 Institutional support: RVO:68081723 Keywords : GTN model * miniaturized specimens * fractography analysis * ductile damage Subject RIV: JL - Materials Fatigue, Friction Mechanics

  1. Procedure of crack resistance estimation for steels from results of standard tensile and impact bend tests

    International Nuclear Information System (INIS)

    Dependences binding minimal level of the static crack resistance, yield point and reduced test temperature Ttest-TB50 are plotted according to the results obtained from test of various structural steels. The given dependences permit suggesting a simple method to calculate static crack resistance by the yield point of steel and critical temperature, corresponding to 50 % viscous component in the fracture of standard impact specimens of the Charpy type. This method has been used to calculate temperature dependences of crack resistance and choice of optimal composition for cold-resistant cast steel

  2. Numerical simulation of a Charpy test and correlation of fracture toughness with fracture energy. Vessel steel and duplex stainless steel of the primary loop; Simulation numerique d`un essai de resilience et correlation entre resilience et proprites de tenacite. Acier de cuve et acier austenoferritique du circuit primaire

    Energy Technology Data Exchange (ETDEWEB)

    Breban, P; Eripret, C. [Departement MTC, Service RNE, Direction des Etudes et Recherches, Electricite de France (EDF), 92 - Clamart (France)

    1995-12-31

    The analysis methods used to evaluate the harmlessness of defects in the components of the primary coolant circuit of pressurized water reactor are based on the knowledge of the failure properties of concerned materials. The toughness is used to be measured through tests performed on normalized samples. But in some cases, especially for the vessel steel submitted to irradiation effects or for cast components in duplex stainless steel sensitive to thermal ageing, these measurements are not available on the material aged in operation. Therefore, fracture resistance has been evaluated through Charpy tests. Toughness is thus obtained on the basis of an empirical correlation. To improve these predictions, a modeling of the Charpy test in the framework of the local approach to fracture has been performed, for both materials. For the vessel steel, a complete evaluation of toughness has been achieved on the basis of a bidimensional viscoplastic modeling under large strain assumptions and a post-treatment with a Weibull model (cleavage fracture). The main hypothesis (partition between plain stress and plain strain areas in the bidimensional modeling) was corrected after a three dimensional calculations with the finite element program Code-Aster. The fracture analysis put into evidence that damage considerations like cavity nucleation and growth have to be introduced in the model in order to improve the description of physical phenomena. Two ways of progress have been suggested and are in course of being investigated, one in the framework of local approach to failure, the other with the help of micro-macro relationship. With regard to the duplex steel, the description of a Charpy (U) test allowed to clearly discriminate between crack initiation and propagation phases. A modeling through an equivalent homogenous material with a damage law based on a modified Gurson potential enables to describe quantitatively both phases of fracture. It clearly appears that a reliable

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

    International Nuclear Information System (INIS)

    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 KIc 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 Kk 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 KJc 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

  4. Single specimen fracture toughness determination procedure using instrumented impact test

    International Nuclear Information System (INIS)

    In the study a new single specimen test method and testing facility for evaluating dynamic fracture toughness has been developed. The method is based on the application of a new pendulum type instrumented impact tester equipped with and optical crack mouth opening displacement (COD) extensometer. The fracture toughness measurement technique uses the Double Displacement Ratio (DDR) method, which is based on the assumption that the specimen is deformed as two rigid arms that rotate around an apparent centre of rotation. This apparent moves as the crack grows, and the ratio of COD versus specimen displacement changes. As a consequence the onset ductile crack initiation can be detected on the load-displacement curve. Thus, an energy-based fracture toughness can be calculated. In addition the testing apparatus can use specimens with the Double ligament size as compared with the standard Charpy specimen which makes the impact testing more appropriate from the fracture mechanics point of view. The novel features of the testing facility and the feasibility of the new DDR method has been verified by performing an extensive experimental and analytical study. (99 refs., 91 figs., 27 tabs.)

  5. Southern Impact Testing Alliance (SITA)

    Science.gov (United States)

    Hubbs, Whitney; Roebuck, Brian; Zwiener, Mark; Wells, Brian

    2009-01-01

    Efforts to form this Alliance began in 2008 to showcase the impact testing capabilities within the southern United States. Impact testing customers can utilize SITA partner capabilities to provide supporting data during all program phases-materials/component/ flight hardware design, development, and qualification. This approach would allow programs to reduce risk by providing low cost testing during early development to flush out possible problems before moving on to larger scale1 higher cost testing. Various SITA partners would participate in impact testing depending on program phase-materials characterization, component/subsystem characterization, full-scale system testing for qualification. SITA partners would collaborate with the customer to develop an integrated test approach during early program phases. Modeling and analysis validation can start with small-scale testing to ensure a level of confidence for the next step large or full-scale conclusive test shots. Impact Testing Facility (ITF) was established and began its research in spacecraft debris shielding in the early 1960's and played a malor role in the International Space Station debris shield development. As a result of return to flight testing after the loss of STS-107 (Columbia) MSFC ITF realized the need to expand their capabilities beyond meteoroid and space debris impact testing. MSFC partnered with the Department of Defense and academic institutions as collaborative efforts to gain and share knowledge that would benefit the Space Agency as well as the DoD. MSFC ITF current capabilities include: Hypervelocity impact testing, ballistic impact testing, and environmental impact testing.

  6. Impact tests of the tungsten coated stainless steels prepared by using magnetron sputtering with ion beam mixing or electron beam alloying treatment

    International Nuclear Information System (INIS)

    Tungsten films were deposited on stainless steel (SS) with ion beam mixing (IBM) or electron beam alloying (EBA) treatment. The ductile–brittle transition behaviors of the specimens were investigated by means of instrumented Charpy impact test at a series of temperature, and SEM was used to observe the morphology of the cross section. Impact tests show that different treatment methods with W films do not have much influence on crack initiation, while EBA treatment with W films can more effectively prevent crack propagation, namely improve the impact toughness of SS than using IBM treatment. The reason that caused this difference was discussed

  7. Impact toughness of tungsten films deposited on martensite stainless steel

    Institute of Scientific and Technical Information of China (English)

    HUANG Ning-kang; YANG Bin; WANG De-zhi

    2005-01-01

    Tungsten films were deposited on stainless steel Charpy specimens by magnetron sputtering followed by electron beam heat treatment. Charpy impact tests and scanning electron microscopy were used to investigate the ductile-brittle transition behavior of the specimens. With decreasing test temperature the fracture mode was transformed from ductile to brittle for both kinds of specimens with and without W films. The data of the crack initiation energy, crack propagation energy, impact absorbing energy, fracture time and deflection as well as the fracture morphologies at test temperature of -70 ℃ show that W films can improve the impact toughness of stainless steel.

  8. CANFLEX fuel bundle impact test

    International Nuclear Information System (INIS)

    This document outlines the test results for the impact test of the CANFLEX fuel bundle. Impact test is performed to determine and verify the amount of general bundle shape distortion and defect of the pressure tube that may occur during refuelling. The test specification requires that the fuel bundles and the pressure tube retain their integrities after the impact test under the conservative conditions (10 stationary bundles with 31kg/s flow rate) considering the pressure tube creep. The refuelling simulator operating with pneumatic force and simulated shield plug were fabricated and the velocity/displacement transducer and the high speed camera were also used in this test. The characteristics of the moving bundle (velocity, displacement, impacting force) were measured and analyzed with the impact sensor and the high speed camera system. The important test procedures and measurement results were discussed as follows. 1) Test bundle measurements and the pressure tube inspections 2) Simulated shield plug, outlet flange installation and bundle loading 3) refuelling simulator, inlet flange installation and sensors, high speed camera installation 4) Perform the impact test with operating the refuelling simulator and measure the dynamic characteristics 5) Inspections of the fuel bundles and the pressure tube. (author). 8 refs., 23 tabs., 13 figs

  9. CANFLEX fuel bundle impact test

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Seok Kyu; Chung, C. H.; Park, J. S.; Hong, S. D.; Kim, B. D.

    1997-08-01

    This document outlines the test results for the impact test of the CANFLEX fuel bundle. Impact test is performed to determine and verify the amount of general bundle shape distortion and defect of the pressure tube that may occur during refuelling. The test specification requires that the fuel bundles and the pressure tube retain their integrities after the impact test under the conservative conditions (10 stationary bundles with 31kg/s flow rate) considering the pressure tube creep. The refuelling simulator operating with pneumatic force and simulated shield plug were fabricated and the velocity/displacement transducer and the high speed camera were also used in this test. The characteristics of the moving bundle (velocity, displacement, impacting force) were measured and analyzed with the impact sensor and the high speed camera system. The important test procedures and measurement results were discussed as follows. 1) Test bundle measurements and the pressure tube inspections 2) Simulated shield plug, outlet flange installation and bundle loading 3) refuelling simulator, inlet flange installation and sensors, high speed camera installation 4) Perform the impact test with operating the refuelling simulator and measure the dynamic characteristics 5) Inspections of the fuel bundles and the pressure tube. (author). 8 refs., 23 tabs., 13 figs.

  10. Influence of Martensite Volume Fraction on Impact Properties of Triple Phase (TP) Steels

    Science.gov (United States)

    Zare, Ahmad; Ekrami, A.

    2013-03-01

    Ferrite-bainite-martensite triple phase (TP) microstructures with different volume fractions of martensite were obtained by changing heat treatment time during austempering at 300 °C. Room temperature impact properties of TP steels with different martensite volume fractions ( V M) were determined by means of Charpy impact testing. The effects of test temperature on impact properties were also investigated for two selected microstructures containing 0 (the DP steel) and 8.5 vol.% martensite. Test results showed reduction in toughness with increasing V M in TP steels. Fracture toughness values for the DP and TP steels with 8.5 vol.% martensite were obtained from correlation between fracture toughness and the Charpy impact energy. Fractography of Charpy specimens confirmed decrease in TP steels' toughness with increasing V M by considering and comparing radial marks and crack initiation regions at the fracture surfaces of the studied steels.

  11. Charpy V-notch properties and microstructures of narrow gap ferritic welds of a quenched and tempered steel plate

    Energy Technology Data Exchange (ETDEWEB)

    Powell, G.L.F.; Herfurth, G. [Commonwealth Scientific and Industrial Research Organization, Woodville (Australia)

    1998-11-01

    Multipass welds of quenched and tempered 50-mm-thick steel plate have been deposited by a single wire narrow gap process using both gas metal arc welding (GMAW) and submerged arc welding (SAW). Of the five welds, two reported much lower Charpy V-notch (CVN) values when tested at {minus} 20 C. The CVN toughness did not correlate with either the welding process or whether the power source was pulsed or nonpulsed. The only difference in the ferritic microstructure between the two welds of low Charpy values and the three of high values was the percentage of acicular ferrite. There was no effect of the percentage of as-deposited reheated zones intersected by the Charpy notch or the microhardness of the intercellular-dendritic regions. In all welds, austenite was the microconstituent between the ferrite laths. The percentage of acicular ferrite correlated with the presence of MnO, TiO{sub 2}, {gamma} Al{sub 2}O{sub 3}, or MnO. Al{sub 2}O{sub 3} as the predominant crystalline compound in the oxide inclusions. In turn, the crystalline compound depended on the aluminum-to-titanium ratio in both the weld deposits and the oxide inclusions. In addition to the presence of less acicular ferrite, the two welds that showed lower Charpy values also reported more oxide inclusions greater than 1 {micro}m in diameter. The combination of more oxide inclusions greater than 1 {micro}m and less acicular ferrite is considered to be the explanation for the lower Charpy values.

  12. Residual stress study by neutron diffraction in the Charpy specimens reconstructed by various welding methods

    International Nuclear Information System (INIS)

    The investigation of welding residual stress is very important for nuclear industry since it can considerably affect the structural integrity of various components and products and their lifetime. In order to evaluate the applicability of various welding methods the residual stress in test Charpy specimens welded by various techniques were analysed using high resolution neutron diffraction. The experiments show that the level of residual stress in welds can be quite high and this fact should be considered when choosing an appropriate welding technique. Key words: neutron diffraction, residual stress, welding

  13. Molecular dynamics simulation of impact test

    Energy Technology Data Exchange (ETDEWEB)

    Akahoshi, Y. [Kyushu Inst. of Tech., Kitakyushu, Fukuoka (Japan); Schmauder, S.; Ludwig, M. [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt

    1998-11-01

    This paper describes an impact test by molecular dynamics (MD) simulation to evaluate embrittlement of bcc Fe at different temperatures. A new impact test model is developed for MD simulation. The typical fracture behaviors show transition from brittle to ductile fracture, and a history of the impact loads also demonstrates its transition. We conclude that the impact test by MD could be feasible. (orig.)

  14. Tensile and impact testing of an HFBR [High Flux Beam Reactor] control rod follower

    International Nuclear Information System (INIS)

    The Materials Technology Group of the Department of Nuclear Energy (DNE) at Brookhaven National Laboratory (BNL) undertook a program to machine and test specimens from a control rod follower from the High Flux Beam Reactor (HFBR). Tensile and Charpy impact specimens were machined and tested from non-irradiated aluminum alloys in addition to irradiated 6061-T6 from the HFBR. The tensile test results on irradiated material showed a two-fold increase in tensile strength to a maximum of 100.6 ksi. The impact resistance of the irradiated material showed a six-fold decrease in values (3 in-lb average) compared to similar non-irradiated material. Fracture toughness (KI) specimens were tested on an unirradiated compositionally and dimensionally similar (to HFBR follower) 6061 T-6 material with Kmax values of 24.8 ± 1.0 Ksi√in (average) being obtained. The report concludes that the specimens produced during the program yielded reproducible and believable results and that proper quality assurance was provided throughout the program. 9 figs., 6 tabs

  15. Tensile and impact behavior of the reduced-activation steels OPTIFER and F82H mod

    International Nuclear Information System (INIS)

    Tensile and charpy impact tests were carried out on some OPTIFER steel grades and F82H mod. The steels show little difference in tensile properties, but pronounced differences in charpy impact properties. Combinations of low ductile-brittle transition temperature (DBTT) and high yield strength are favored for OPTIFER-IV. After aging at 600 deg. C and higher, F82H mod steel embrittles due to precipitation of Laves phase (Cr, Fe)2W, whereas OPTIFER-IV is resistant to aging

  16. Extended analysis of WWER-1000 Charpy test data

    International Nuclear Information System (INIS)

    The aim of this work is to study the embrittlement rate of WWER-1000 RPV weld metal with high Ni content and to determine influence of neutron irradiation on partial energies of ductile crack initiation, stable and unstable crack propagation and post crack arrest. (author)

  17. Auburn Micrometeoroid Impact Test Data Analysis

    Science.gov (United States)

    Perrygo, Charles; Best, Steve; Stahl, H. Philip (Technical Monitor)

    2001-01-01

    This presentation provides an overview and summary of micrometeoroid impact testing performed by Auburn University and an analysis of the test results. The testing at Auburn utilized existing facilities at Auburn to generate hypervelocity impacts into multiple layers of thin Kapton films representative of the NASA concept for the NGST sunshield. The test data consists of impactor particle mass and velocity, and for each film layer, the number and size of holes generated by the initial impact and resulting impact debris. The analysis consists of combining the test data with existing impact effects models and the micrometeoroid environment at the L2 operating location of NGST to predict sunshield degradation.

  18. High Pressure Quick Disconnect Particle Impact Tests

    Science.gov (United States)

    Rosales, Keisa R.; Stoltzfus, Joel M.

    2009-01-01

    NASA Johnson Space Center White Sands Test Facility (WSTF) performed particle impact testing to determine whether there is a particle impact ignition hazard in the quick disconnects (QDs) in the Environmental Control and Life Support System (ECLSS) on the International Space Station (ISS). Testing included standard supersonic and subsonic particle impact tests on 15-5 PH stainless steel, as well as tests performed on a QD simulator. This paper summarizes the particle impact tests completed at WSTF. Although there was an ignition in Test Series 4, it was determined the ignition was caused by the presence of a machining imperfection. The sum of all the test results indicates that there is no particle impact ignition hazard in the ISS ECLSS QDs. KEYWORDS: quick disconnect, high pressure, particle impact testing, stainless steel

  19. Instrumentation of a Charpy-pendulum. Additional data obtained from it and its application to nuclear reactor pressure vessels surveillance programs

    International Nuclear Information System (INIS)

    Charpy test gives information about a material dynamic fracture behavior. In a plain Charpy test, this information is the absorbed energy during fracture of the specimen, lateral deformation and the percentage of ductile fracture of the specimen. These parameters can then be used for the determination of the material response to a dynamic applied load, and are used at present to determine the brittle-ductile transition temperature of a material. However, there is a lot of additional information that can be obtained from a Charpy test, which is vital for the case of surveillance programs of nuclear power plants, where it is necessary to get the most available information from the specimens to be tested, because each one of them was irradiated for many years under temperature and neutronic flux conditions similar to that of the internal surface of the reactor pressure vessel, which converts these specimens in unique and very expensive ones. This additional information can be obtained from the curve that determines the evolution of the applied force to the specimen throughout the time involved in its fracture. It was possible to instrument a Charpy pendulum at a fraction of the cost necessary to buy an instrumentation package like the ones available in the market, and since the instrumentation equipment obtained is easy to transport. It has the additional advantage that can be used to instrument any other pendulum replacing only the hammer of the pendulum with a instrumented one for that pendulum. (author)

  20. Impact toughness improvement of high-strength aluminium alloy by intrinsic and extrinsic fracture mechanisms via hot roll bonding

    International Nuclear Information System (INIS)

    A multilayer aluminium laminate comprising 10 layers of Al-Zn-Mg-Cu alloy (82 vol.%) and nine layers of pure aluminium (18 vol.%) has been processed by hot rolling. The rolled laminate was characterized by electron backscattering diffraction, Charpy impact and shear tests. The multilayer laminate showed an outstanding Charpy impact toughness, which was 18 times higher than that for the as-received Al-Zn-Mg-Cu alloy. The improvement in damage tolerance was due to the high volume fraction of the high-strength aluminium and extrinsic fracture mechanisms.

  1. Fractographic and microstructural aspects of fracture toughness testing in irradiated 304 stainless steel

    International Nuclear Information System (INIS)

    Fracture toughness and Charpy impact test results on 304 stainless steel baseplate, weld and heat-affected zone (HAZ) tested at 250C and 1250C are correlated with the microstructural and fractographic features observed in these materials. Specimens were collected from several sections of 12.7 mm (0.5 in.) wall thickness piping removed from a process system, and were characterized by different material chemistries and thermomechanical histories. As a result, mechanical properties vary over a considerable range from one pipe section to another. The presence of delta ferrite in some of the samples caused significant degradations in the toughness properties for certain crack orientations. Decreases in Charpy impact energies occur in the same material for different crack orientations. Materials irradiated showed 40% decreases in Charpy impact energy, but little change in fracture morphology. An increase in the test temperature resulted in an expected increase in Charpy energies for all materials. Fractographic features did not change appreciably with respect to the 1000C increase in test temperature. In unirradiated specimens, a test temperature increase caused lower J/sub Ic/ and J-R curve values with tearing modules values increased. The latter is due to the large decreases in tensile strength with increasing test temperature. The weld metals tend to have the highest tearing resistance, while the HAZ's tend to have the lowest. 30 figs., 3 tabs

  2. On the Use of the Master Curve based on the Precracked Charpy Specimen

    International Nuclear Information System (INIS)

    Recently, worldwide interest has been demonstrated in the evaluation of the use of the Master Curve approach to characterize fracture toughness of ferritic steels in the transition regime. This was acknowledged by the recent release of the ASTM Standard Test Method for Determination of Reference Temperature, T0, for Ferritic Steels in the Transition Range (E1921). The present work aims to investigate the use of the Charpy specimen along with the Master Curve approach to derive the fracture toughness behaviour of reactor pressure vessel steels. Therefore, four well characterized and documented reactor pressure vessel steels were selected. A large experimental program to measure fracture toughness with Charpy size specimens was carried out. Four important aspects were investigated: (1) the T0 determination as a function of test temperature; (2) the E1921 specimen size requirement (factor M=30); (3) the censoring procedure for specimens not satisfying the E1921 size requirements; (4) the estimation of the fracture toughness lower bound, and its comparison to the ASME KIC curve. It is found that within the experimental and statistical uncertainties, the reference temperature T0 is not affected by the test temperature, even when data are not valid according to E1921 requirements. By application of the censoring procedure, the determination of the reference temperature may lead to non conservative results. Comparison to larger specimen size suggests the use of M=60 rather than 30 to limit the loss of constraint, in agreement with finite element calculations. Nevertheless, the differences are not large enough to be statistically significant. The lower bound based on the Master Curve is very close to the experimental lower bound, while the ASME KIC curve trends to be over conservative. Replacing RTNDT by the new index, RTTo, in the ASME KIC equation reduces this over conservatism

  3. 30 CFR 7.46 - Impact test.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Impact test. 7.46 Section 7.46 Mineral... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.46 Impact test. (a) Test... individual cells. At the test temperature range of 65 °F -80 °F (18.3 °C-26.7 °C), apply a dynamic force...

  4. Charpy notch toughness and hardness of reheated martensite and lower bainite

    Directory of Open Access Journals (Sweden)

    F. Vodopivec

    2010-07-01

    Full Text Available A high strength low alloyed (HSLA V-Nb steel was heat treated to martensite and lower bainite with different grain size, reheated for 3 seconds at 750 °C and air cooled. Charpy notch tests were performed from -100 °C to 60 °C and the hardness assessed at room temperature. For as delivered steel and lower bainite, the upper shelf toughness was above 200 J and the transition temperature low, while, for martensite the upper shelf toughness threshold was aproximateky at 0 °C. After reheating, notch toughness was decreased moderatly for martensite and strongly for lower bainite. Independently on grain size, lower bainite was more propensive than martensite to embritlement after short reheating in the (α + β range. For martensite, the change of notch toughness was not related to change of hardness, as by lower hardness lower, also toughness was lower.

  5. Impact testing of transportation-flasks

    International Nuclear Information System (INIS)

    The literature describing flask testing is reviewed and it is concluded that, even though there are numerous references to instrumented impact testing of flasks, there remains a need for a collection of data from carefully constructed and fully instrumented model tests for thorough validation of analytical tools. (author)

  6. Development of a sealing process of capsules for surveillance test tubes of the vessel in nuclear power plants

    International Nuclear Information System (INIS)

    The surveillance capsule is composed by the support, three capsules for impact test tubes, five capsules for tension test tubes and one porta dosemeters. The capsules for test tubes are of two types: rectangular capsule for Charpy test tubes and cylindrical capsule for tension test tubes. This work describes the development of the welding system to seal the capsules for test tubes that should contain helium of ultra high purity to a pressure of 1 atmosphere. (Author)

  7. Evaluation of impact and fatigue properties on austempered ductile iron

    OpenAIRE

    Arias Fernández, Sergio

    2009-01-01

    Austempered Ductile Iron (ADI) proved to be an excellent material as it possesses attractive properties: high strength, ductility and toughness are combined with good wear resistance and machinability. In this work impact and the fatigue properties have been evaluated for low alloyed Austempered Ductile Iron. To do this, Charpy-type impact test for austempered ductile iron was performed by the standard ASTM A 327M and Fatigue Crack Growth Rates (FCGR) were measured by the stand...

  8. Impact tests with fuel element cans

    International Nuclear Information System (INIS)

    Impact tests with storage tanks for irradiated HTR-fuel balls have been carried out. The determination of the damages of the storage tanks falling from a heigth of 7 m and the graphite balls, which have been used in place of the fuel elements, has been the aim of these tests. The main results are: 1. The leakage of the three impact tested tanks (2 of type ASSE, 1 of type AVR-TL) has not increased due to the impact. 2. The deformation of the tanks caused by the impact exceed the tank specification for dimensions and shape. 3. The graphit ball damages depend on the type of tank and on the angle of impact. The damages of graphit balls in the tank of type AVR-TL have been neglectable small. (orig.)

  9. Finite element simulation of wheel impact test

    Directory of Open Access Journals (Sweden)

    S.H. Yang

    2008-06-01

    Full Text Available Purpose: In order to achieve better performance and quality, the wheel design and manufacturing use a number of wheel tests (rotating bending test, radial fatigue test, and impact test to insure that the wheel meets the safety requirements. The test is very time consuming and expensive. Computer simulation of these tests can significantly reduce the time and cost required to perform a wheel design. In this study, nonlinear dynamic finite element is used to simulate the SAE wheel impact test.Design/methodology/approach: The test fixture used for the impact test consists of a striker with specified weight. The test is intended to simulate actual vehicle impact conditions. The tire-wheel assembly is mounted at 13° angle to the vertical plane with the edge of the weight in line with outer radius of the rim. The striker is dropped from a specified height above the highest point of the tire-wheel assembly and contacts the outboard flange of the wheel.Because of the irregular geometry of the wheel, the finite element model of an aluminium wheel is constructed by tetrahedral element. A mesh convergence study is carried out to ensure the convergence of the mesh model. The striker is assumed to be rigid elements. Initially, the striker contacts the highest area of the wheel, and the initial velocity of the striker is calculated from the impact height. The simulated strains at two locations on the disc are verified by experimental measurements by strain gages. The damage parameter of a wheel during the impact test is a strain energy density from the calculated result.Findings: The prediction of a wheel failure at impact is based on the condition that fracture will occur if the maximum strain energy density of the wheel during the impact test exceeds the total plastic work of the wheel material from tensile test. The simulated results in this work show that the total plastic work can be effectively employed as a fracture criterion to predict a wheel

  10. Investigations on the impact strength of constructional high-strength Weldox steel at lowered temperature

    OpenAIRE

    W. Ozgowicz; E. Kalinowska-Ozgowicz

    2008-01-01

    Purpose: The paper presents the results of investigations concerning the impact strength of thick steel plates at lowered temperature obtained by industrial smelting of micro-alloyed steel of the type S1100QL (Weldox 1100) and S1300QL (Weldox 1300) with a yield strength of 1100-1300 MPa.Design/methodology/approach: The main methods used for these researches were the impact test Charpy V at lower temperatures, and metallographic observations. The tested samples at lower temperature have also b...

  11. Clean Cast Steel Technology: Effect of Micro-porosity on Tensile and Charpy Properties of Four Cast Steels

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, John, A.; Bates, Charles, E.

    2005-09-19

    The effect of these large shrink cavities on mechanical properties could be easily calculated using well established engineering formulas. Over the years, increases in computational and metallurgical resources have allowed the modeler to improve accuracy and increase the complexity of numerical predictors. An accurate prediction of micro-porosity, not observable using conventional radiographic techniques, and an engineering understanding of the effect on mechanical properties would give a designer confidence in using a more efficient casting design and a lower safety factor. This will give castings an additional design advantage. The goal of this project is to provide current and future modelers/designers with a tensile and Charpy property dataset for validation of micro-porosity predictors. The response of ultimate strength, elongation, and reduction in area to micro-porosity was very similar in all four alloys. Ultimate strength was largely unaffected by tensile fracture surface porosity until values of about 25% were reached and decreased linearly with increasing values. Elongation and reduction in area decreased sharply after less than 5% fracture surface porosity. Niyama values of about 0.7 were produced sound material and acceptable tensile properties. Ultrasonic velocities of 0.233 in/usec and higher produced acceptable tensile properties. Metallographic examination revealed a ratio of 4-6 to 1 in fracture surface porosity to metallographic porosity. Charpy impact properties were largely unaffected by the microporosity concentrations examined in this study and did not correlate to either Niyama values, fracture surface porosity, or metallographic porosity.

  12. The evaluation of dynamic cracking resistance of chosen casting alloys in the aspect of the impact bending test

    Directory of Open Access Journals (Sweden)

    J.Sadowski

    2008-10-01

    Full Text Available The increase of quality and durability of produced casting alloys can be evaluated on the base of material tests performed on a high level. One of such modern test methods are tests of the dynamic damage process of materials and the evaluation on the base of obtained courses F(f, F(t of parameters of dynamic cracking resistance KId, JId, performed with the usage of instrumented Charpy pendulums. In the paper there was presented the evaluation of dynamic cracking resistance parameters of casting alloys such as: AK12 aluminum alloy, L20G cast steel and spheroid cast iron. The methodology of the evaluation of that parameters was described and their change as well, for the AK12 alloy with the cold work different level, L20G cast steel cooled from different temperatures in the range +20oC -60oC, and for the spheroid cast iron in different stages of treatment i.e. raw state, after normalization, spheroid annealing and graphitizing annealing.Obtained parameters of dynamic cracking resistance KId, JId of tested casting alloys enabled to define the critical value of the ad defect that can be tolerated by tested castings in different work conditions with impact loadings.

  13. Re-utilization by '' Stud Welding'' of capsules charpy-V belonged to surveillance programs

    International Nuclear Information System (INIS)

    The perspectives of nuclear plants life extension that are approximating to their end of design life compels to make new surveillance programs. The re-utilization of specimens belonging to surveillance capsules already tested in these new surveillance programs seems be a solution worldwide accepted. The two possible re-utilization processes of this irradiated material are: Subsized specimens and Reconstitution. While the first alternative (Subsized specimens) outlines serious problems for apply the results, the reconstitution eliminates this problem, since the resulting specimens after of the reconstruction procedure would be of the same dimensions that the original. The reconstruction process involves welds, and therefore it has associated the specific problems of this type of joints. Furthermore, by be tried to material irradiated with certain degree of internal damage, that is the variable to evaluate, requires that the heat contribution to the piece not originate local thermal treatments that alter its mechanical qualities. In this work has been followed the evolution by the variables of the weld process and their influence on the quality by the union from metallographic al point of view as well as mechanical for a weld procedure by Stud Welding. The principal objective is to optimize said parameters to assure a good mechanical continuity, without detriment of the microstructural characteristics of the original material. To verify this last have been accomplished with metallographical tests, temperature profile, hardness and will be carried out also Charpy tests. (Author)

  14. Applicability of smaller than Charpy specimens for fracture toughness characterization with the VTT method

    International Nuclear Information System (INIS)

    The term fracture toughness usually refers to the linear elastic fracture resistance parameter KIC. In the case of structural steels, the estimation of KIC is limited to the lower shelf of toughness or require extremely large specimens. This specimen size requirement has been one major obstacle for applying fracture mechanics in structural integrity assessment outside aviation, nuclear and off-shore industries. During the last decade, a statistical data treatment methodology, based on a micro-mechanistic cleavage fracture model, combined with elastic plastic finite element analysis has enabled the fracture toughness to be characterized with small specimens in the ductile-to-brittle transition region. The methodology is known as the VTT method or the Master Curve procedure. The development has led to a new testing standard for fracture toughness testing of ferritic steels in the transition range. Here, the premises for the methodology are described and its validity range is discussed. Presently the methodology has been validated for as small as 10.10 mm2 bend specimens, but the use of even smaller specimens is under investigation. Specifically, results obtained with three different sub-Charpy specimen configurations are presented and discussed. (author)

  15. Statistical Analysis of Charpy Transition Temperature Shift in Reactor Pressure Vessel Steels: Application of Nuclear Materials Database(MatDB)

    International Nuclear Information System (INIS)

    The MDPortal contains various technical documents on the degradation and development of nuclear materials. Additionally, the nuclear materials database (MatDB) is also launched in KAERI recently. The MatDB covers the mechanical properties of various nuclear structural materials used as the components: a reactor pressure vessel, steam generator, and primary and secondary piping. In this study, we introduced MatDB briefly, and analyzed the Charpy transition temperature shift in reactor pressure vessel steels of Korean nuclear power plants retrieved from MatDB. It can show an application of the MatDB to the real case of material degradations in NPPs. The MatDB includes the tensile results, Charpy results, fatigue results and J-R curve results at present. In the future other properties such as creep, fracture toughness, and SCC degradations are going to be added consistently. The data from MatDB were successfully applied to estimate the TTS analysis of Korean RPV steels in surveillance tests

  16. Development of a sealing process of capsules for surveillance test tubes of the vessel in nuclear power plants; Desarrollo de proceso de sellado de capsulas para probetas de vigilancia de la vasija en nucleoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Romero C, J.; Fernandez T, F.; Perez R, N.; Rocamontes A, M.; Garcia R, R. [ININ, Km 36.5 Carretera Mexico-Toluca, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The surveillance capsule is composed by the support, three capsules for impact test tubes, five capsules for tension test tubes and one porta dosemeters. The capsules for test tubes are of two types: rectangular capsule for Charpy test tubes and cylindrical capsule for tension test tubes. This work describes the development of the welding system to seal the capsules for test tubes that should contain helium of ultra high purity to a pressure of 1 atmosphere. (Author)

  17. Prediction of the brittle fracture toughness value of a RPV steel from the analysis of a limited set of Charpy results

    International Nuclear Information System (INIS)

    Our objective is to establish a method to be able to determine fracture toughness of a reactor pressure vessel (RPV) by using the small number of Charpy specimens used in the reactor surveillance program. Previous studies have shown that it is possible to determine fracture toughness from Charpy tests. Another point is to determine if statistical effects are compatible with a restricted number of specimens, this paper deals with this point and presents a methodology that is applicable to the case of irradiated materials from the surveillance program. Several conclusions can be drawn from this study: -) When determining failure parameters, we gain most accuracy by increasing the number of samples from 3 to about 6; -) it is possible to evaluate brittle fracture toughness using local approach, either by using Beremin or Renevey model; -) The effect of using a small number of Charpy specimens to determine fracture toughness in brittle fracture is evaluated. The error in the evaluation of fracture toughness is much smaller than the experimental dispersion itself. (A.C.)

  18. Impact sensitivity test of liquid explosives

    Science.gov (United States)

    Tiutiaev, Andrei; Trebunskih, Valeri; Dolzhikov, Andrei; Zvereva, Irina

    2015-06-01

    The sensitivity of liquid explosive in the presence of gas bubbles increases many times as compared with the liquid without gas bubbles. If we consider that in the liquid as a result of convection, wave motion, shock, etc. gas bubbles are easily generated, the need to develop a method for determining sensitivity of liquid explosives to impact and a detailed study of the ignition explosives with bubbles is obvious. On a mathematical model of a single steam bubbles in the fluid theoretically considered the process of initiating explosive liquid systems to impact. For the experimental investigation, the well-known K-44 -II and the so-called appliance No. 1 were used. Instead of the metal cap in the standard method in this paper there was polyurethane foam cylindrical container with LHE, which is easily deforms by impact. A large number of tests with different liquid explosives were made. It was found that the test LHE to impact in appliance No. 1 with polyurethane foam to a large extent reflect the real mechanical sensitivity due to the small loss of impact energy on the deformation of the metal cap, as well as the best differentiation LHE sensitivity due to the higher resolution method .

  19. Visualization of impact damaging of carbon/epoxy panels

    Science.gov (United States)

    Boccardi, Simone; Boffa, Natalino Daniele; Carlomagno, Giovanni Maria; Meola, Carosena; Ricci, Fabrizio

    2016-05-01

    This work is concerned with impact damaging of carbon/epoxy materials. Specimens of different thickness are herein considered, which involve several fibers orientations and stacking sequences. Impact tests are carried out at different energies with a modified Charpy pendulum. The specimen surface opposite to that struck by the impactor is viewed by an infrared imaging device. Then, a sequence of thermal images is acquired during each impact test. Through the temperature variations experienced by the specimen surface, post-processing of such images supplies the likely occurred damage. In addition, specimens are non-destructively evaluated with lock-in thermography to visualize any manufacturing defects, as well as impact damage.

  20. Experiment HFIR-MFE-T3 for low-temperature irradiation of miniaturized Charpy V-notch specimens of nickel-doped ferritic steels

    International Nuclear Information System (INIS)

    The HFIR-MFE-T3 experimental capsule is described. This experiment consists of miniature Charpy V-notch specimens of 12 Cr-1 MoVW and 12 Cr-1 MoVW-2 Ni alloys. The different levels of nickel will result in different helium levels generated during irradiation, and thus will allow for an evaluation of the effect of helium on impact properties. Irradiation of the capsule has started with projected fluence at midplane that will produce 10 dpa expected by January 1982

  1. Degradation of impact fracture during accelerated aging of weld metal on microalloyed steel

    International Nuclear Information System (INIS)

    The effect of accelerated aging on the toughness and fracture of the longitudinal weld metal on an API5L-X52 line pipe steel was evaluated by Charpy V-notch impact test, fracture analysis and transmission electron microscopy. Aging was performed at 250 degree centigrade for 100 to 1000 h. The impact results indicated a significant reduction in the fracture energy and impact toughness as a function of aging time, which were achieved by the scanning electron microscope fractography that showed a decrease in the vol fraction of microvoids by Charpy ductile failure with the aging time, which favored the brittle fracture by transgranular cleavage. The minimum vol fraction of microvoids was reached at 500 h due to the peak aged. The microstructural analysis indicated the precipitation of transgranular iron nano carbides in the aged specimens, which was related to the deterioration of toughness and change in the ductile to brittle behavior. (Author) 15 refs

  2. Integration of fracture mechanics tests into quality management and quality assurance systems for fine-grained structural steels

    International Nuclear Information System (INIS)

    Fracture toughness reference data were to be established by fracture mechanics tests. The weldable, fine-grained structural steel E StE 355 was tested for this purpose by a variety of methods. The qualitative toughness properties were determined by conventional Charpy impact tests. The shelf energy values of toughness and the transition temperatures were derived from the temperature-dependent curves of the parameters of impact energy, lateral spreading, and crystalline fraction. The quantitative characterisation of the toughness properties required fracture mechanics data, which were obtained using the instrumented precracked Charpy test. Upon assignment of the measured dynamic fracture toughness data to the relevant transition temperatures defined in the qualification requirements, and upon determination of the link between crack initation toughness and notch impact shelf energy data, the advantage and necessity of an evaluation of the material's toughness from the fracture-mechanical point of view became very clear. It was recognized that the requirements for qualification and quality assurance of fine-grained structural steels have to be reviewed taking into account the criteria of fracture mechanics. The paper explains a newly designed quality management and quality assurance system incorporating fracture mechanics data derived from Charpy impact tests. (orig.)

  3. The Influence of Instrumented Striker Configuration on the Results of Dynamic Toughness Testing

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.

    2008-09-15

    Several studies are available on the influence of the edge radius of instrumented strikers (ASTM - 8 mm or ISO - 2 mm) on the results of both non instrumented and instrumented Charpy tests. This paper investigates the effect of using either a 2 mm or a 8 mm striker when performing dynamic toughness tests at impact loading rates on precracked Charpy specimens. Existing data from tests run in the ductile-to-brittle region (dynamic Master Curve reference temperature) and in the upper shelf regime (ductile initiation fracture toughness and crack resistance curves) have been analyzed. The results show that 2 mm strikers tend to yield lower cleavage fracture toughness in the transition region (although the effect cannot be considered statistically significant), whereas the influence of striker configuration is negligible in the upper shelf regime when data are generated using the low-blow multiple-specimen technique.

  4. Galileo battery testing and the impact of test automation

    Science.gov (United States)

    Pertuch, W. T.; Dils, C. T.

    1985-01-01

    Test complexity, changes of test specifications, and the demand for tight control of tests led to the development of automated testing used for Galileo and other projects. The use of standardized interfacing, i.e., IEEE-488, with desktop computers and test instruments, resulted in greater reliability, repeatability, and accuracy of both control and data reporting. Increased flexibility of test programming has reduced costs by permitting a wide spectrum of test requirements at one station rather than many stations.

  5. Degradation of impact fracture during accelerated aging of weld metal on microalloyed steel; Degradacion de la tenacidad al impacto durante el envejecimiento acelerado de soldadura en acero microaleado

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Arista, B.; Hallen, J. M.; Albiter, A.; Angeles-Chavez, C.

    2008-07-01

    The effect of accelerated aging on the toughness and fracture of the longitudinal weld metal on an API5L-X52 line pipe steel was evaluated by Charpy V-notch impact test, fracture analysis and transmission electron microscopy. Aging was performed at 250 degree centigrade for 100 to 1000 h. The impact results indicated a significant reduction in the fracture energy and impact toughness as a function of aging time, which were achieved by the scanning electron microscope fractography that showed a decrease in the vol fraction of microvoids by Charpy ductile failure with the aging time, which favored the brittle fracture by transgranular cleavage. The minimum vol fraction of microvoids was reached at 500 h due to the peak aged. The microstructural analysis indicated the precipitation of transgranular iron nano carbides in the aged specimens, which was related to the deterioration of toughness and change in the ductile to brittle behavior. (Author) 15 refs.

  6. Test System Impact on System Availability

    DEFF Research Database (Denmark)

    Pau, L. F.

    1987-01-01

    The specifications are presented for an imperfect automatic test system (ATS) (test frequency distribution, reliability, false alarm rate, nondetection rate) in order to account for the availability, readiness, mean time between unscheduled repairs (MTBUR), reliability, and maintenance of the...... system subject to monitoring and test. A time-dependent Markov model is presented, and applied in three cases, with examples of numerical results provided for preventive maintenance decisions, design of an automatic test system, buffer testing in computers, and data communications....

  7. A comparison of FRP-sandwich penetrating impact test methods

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, M. [VTT Manufacturing Technology, Espoo (Finland). Maritime and Mechanical Engineering

    1996-12-31

    The main objective of this project is to identify the test methods which provide useful results for the different types of penetrating impacts occurring in sandwich structures. A series of penetrating impact tests on FRP-sandwich panels is performed using three different test methods and the results of the test methods are compared. The test methods used are the standardised method ISO 6603 and two non-standardised methods. The first non-standardised method uses a pyramid-shaped impactor instead of the cylindrical impactor used in the ISO 6603 method. In the second non-standardised method, the impact test is performed quasistatically using a cylindrical impactor. Possible stages of failure occurring in FRP-sandwich during a penetrating impact are illustrated. A comprehensive test method should be able to provoke various failure modes, as observed in impact failures of actual sandwich structures. The results obtained with the three test methods lead to a different ranking in impact strength of the panels. Hence, impact test results obtained with different test methods are not even qualitatively comparable. The pyramid-shaped impactor is able to generate clearly more failure modes than the cylindrical impactor in the ISO 6603 method. Therefore, it is considered to be of more practical value for determining the impact strength of PRP-sandwich structures. (orig.) (15 refs.)

  8. Impact resistance of fiber composites - Energy-absorbing mechanisms and environmental effects

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1985-01-01

    Energy absorbing mechanisms were identified by several approaches. The energy absorbing mechanisms considered are those in unidirectional composite beams subjected to impact. The approaches used include: mechanic models, statistical models, transient finite element analysis, and simple beam theory. Predicted results are correlated with experimental data from Charpy impact tests. The environmental effects on impact resistance are evaluated. Working definitions for energy absorbing and energy releasing mechanisms are proposed and a dynamic fracture progression is outlined. Possible generalizations to angle-plied laminates are described.

  9. Impact strength of the uranium-6 weight percent niobium alloy between -1980 and +2000C

    International Nuclear Information System (INIS)

    A study was conducted to determine if a ductile-to-brittle transition wxisted for the uranium-6 wt % niobium (U-6Nb) alloy. Standard V-notched Charpy bars were made from both solution-quenched and solution-quenched and aged U-6Nb alloy and were tested between -1980 and +2000C. It was found that a sharp ductile-brittle transition does not exist for the alloy. A linear relationship existed between test temperature and impact strength, and the alloy retained a significant amount of impact strength even at very low temperatures. 9 figures

  10. Crack lengths calculation by the unloading compliance technique for Charpy size specimens

    International Nuclear Information System (INIS)

    The problems with the crack length determination by the unloading compliance method are well known for Charpy size specimens. The final crack lengths calculated for bent specimens do not fulfil ASTM 1820 accuracy requirements. Therefore some investigations have been performed to resolve this problem. In those studies it was considered that the measured compliance should be corrected for various factors, but satisfying results were not obtained. In the presented work the problem was attacked from the other side, the measured specimen compliance was taken as a correct value and what had to be adjusted was the calculation procedure. On the basis of experimentally obtained compliances of bent specimens and optically measured crack lengths the investigation was carried out. Finally, a calculation procedure enabling accurate crack length calculation up to 5 mm of plastic deflection was developed. Applying the new procedure, out of investigated 238 measured crack lengths, more than 80% of the values fulfilled the ASTM 1820 accuracy requirements, while presently used procedure provided only about 30% of valid results. The newly proposed procedure can be also prospectively used in modified form for specimens of a size different than Charpy size. (orig.)

  11. Non-destructive indication of irradiation embrittlement of ferromagnetic steel by the method of magnetic adaptive testing

    Energy Technology Data Exchange (ETDEWEB)

    Tomas, I. [Inst. of Physics, ASCS, Prague (Czech Republic); Vertesy, G. [Research Inst. for Technical Physics and Materials Science, Budapest (Hungary); Kocik, J. [Nuclear Research Inst. Rez plc and Research Centre Rez Ltd. (Czech Republic)

    2007-07-01

    Method of magnetic adaptive testing is suggested as a highly promising non-destructive alternative of destructive Charpy impact tests for monitoring irradiation embrittlement of surveillance samples in pressure vessels of nuclear reactors. Magnetic adaptive testing is a non-destructive method, it is technically very simple, it offers much higher sensitivity than the traditional magnetic approaches and it is ideally suited even for in-situ tests inside the hot nuclear pressure vessels. The method is described and its efficiency and sensitivity is illustrated on an example of mechanically embrittled series of round robin samples tested in a number of laboratories by different magnetic methods. (orig.)

  12. Mark III confirmatory test program: one-third scale pool swell impact tests, Test Series 5805

    International Nuclear Information System (INIS)

    A series of 51 blowdown tests was performed in support of the Mark III pressure suppression concept with particular emphasis on the effect of pool swell impact on structures located above the suppression pool. The integrated steam generator and drywell of the Pressure Suppression Test Facility was used to accelerate the water mass in the one-third scale suppression pool to velocities typical of Mark III containments, and the impact of this water on I-beams, pipes, and gratings was investigated. The loading mechanism was found to be high velocity pressure waves which traveled along the surface of impacted structures, with a wave velocity defined by the movement of the points of intersection between the horizontal target structures and the rising curved pool surface. The impulse associated with this loading was found to correlate as a function of pool approach velocity, target geometry, and water ligament thickness, the last variable being important only when the ligament thickness approached target dimensions. For pool surface velocities expected to occur in Mark III, the maximum measured impulses for all targets were 35 percent or less of those being used for Mark III design specifications. For targets of circular cross section, loads were one-half or less than the values for comparable flat surfaces. Both the factor of three and the pipe shape factor must be considered when evaluating the conservatism in the Mark III design specifications

  13. Test and evaluation of pressure vessel materials

    International Nuclear Information System (INIS)

    We have prepared a method for analyzing the Charpy impact test data, which is deduced from ''the standard anelastic solid equation''. The theoretical expression for the absorbed energy is in a form of W=Wsub(U)+(Wsub(R)-Wsub(U))/ [1+(ωtau)2] showing the Debye characteristics and where tau is given by the Arrhenius equation; tau=tau0 exp(ΔH/ksub(B)T). Four measurable parameters, at the present stage, can characterize the dynamic hehavior of cracking (Charpy impact result). They are the upper shelf energy(Wsub(R), the lower shelf energy (Wsub(U)), the activation energy of crack (ΔH, and wtau(0) where w tau(0) are the resonance frequency of the specimen and the jumping pre-exponential factor of propagating crack respectively. However the states of R (relaxed) and U (un-relaxed) should be defined from reasonable physical conditions in the future and it is possible that Wsub(U) is small enough to be taken as zero. The effects of irradiation, alloying elements, and heat treatment on the impact results should be interpreted as changes in the above characteristic parameters. The present method has been applied for weld metal of SA 508-2 irradiated up to a fluence of 4x1018n/cm2, E>1.0Mev, resulting in about 29% decrease in Wsub(R), negligible change in Wsub(U), 5.6 times increase in ωtau0, and no change in ΔH. This seems to indicate that irradiation degrades an average value of YOUNG's modulus so that cracks propagate more easily and it does not effect on breaking the lattice bond. However much more systematic analyses should be necessary for correct judgment. It is concluded that the present method is quite adequate for analyzing the Charpy impact data even though plastic deformation in the specimen was not considered separately so that the method should be applied for various cases in order to evaluate the proper trend of effects of irradiation, alloying elements, and heat treatment on the Charpy impact results. (Author)

  14. Numerical simulation of small scale soft impact tests

    Energy Technology Data Exchange (ETDEWEB)

    Varpasuo, Pentti [Fortum Nuclear Services Ltd. P.O. Box 10, 00048 Fortum (Finland)

    2008-07-01

    This paper describes the small scale soft missile impact tests. The purpose of the test program is to provide data for the calibration of the numerical simulation models for impact simulation. In the experiments, both dry and fluid filled missiles are used. The tests with fluid filled missiles investigate the release speed and the droplet size of the fluid release. This data is important in quantifying the fire hazard of flammable liquid after the release. The spray release velocity and droplet size are also input data for analytical and numerical simulation of the liquid spread in the impact. The behaviour of the impact target is the second investigative goal of the test program. The response of reinforced and pre-stressed concrete walls is studied with the aid of displacement and strain monitoring. (authors)

  15. Numerical simulation of small scale soft impact tests

    International Nuclear Information System (INIS)

    This paper describes the small scale soft missile impact tests. The purpose of the test program is to provide data for the calibration of the numerical simulation models for impact simulation. In the experiments, both dry and fluid filled missiles are used. The tests with fluid filled missiles investigate the release speed and the droplet size of the fluid release. This data is important in quantifying the fire hazard of flammable liquid after the release. The spray release velocity and droplet size are also input data for analytical and numerical simulation of the liquid spread in the impact. The behaviour of the impact target is the second investigative goal of the test program. The response of reinforced and pre-stressed concrete walls is studied with the aid of displacement and strain monitoring. (authors)

  16. Development of the plant life management technology for RPV steels [ - Current status of surveillance test specimen reconstitution program -

    International Nuclear Information System (INIS)

    In order to develop the reconstitution technology to standardize surveillance test specimen reconstitution practices to deal with the extended service life of reactor pressure vessels, the Japan Power Engineering and Inspection Corporation (JAPEIC) has been carried out the project entrusted by the Ministry of International Trade and Industry (MITI). We focus on a correlation between the reduction of absorbed energy and the interaction of the heat affected zone (HAZ) and the plastic zone, to establish applicable reconstitution conditions for Charpy specimens. The relationship between the plastic zone width and the absorbed energy has been obtained by estimating the plastic zone width from the hardness distribution of the Charpy specimens. Impact tests of reconstituted specimens with 10 mm-length insert using the surface activated joining method were performed and the test results were compared to those obtained by the standard specimens. By comparing the length of insert material to the sum of HAZ width and plastic zone width, it is clear that the interaction causes the reduction of the absorbed energy. Hence, the applicable conditions of reconstituted Charpy specimens could be assessed by comparing the insert length to the sum of HAZ width and plastic zone width. Moreover the effects of the possible deviations from the standard shape and size specimens for the reconstituted specimens were studied. (authors)

  17. Impact test on natural fiber reinforced polymer composite materials

    Directory of Open Access Journals (Sweden)

    D. Chandramohan

    2013-06-01

    Full Text Available In this research, natural fibers like Sisal (Agave sisalana, Banana (Musa sepientum & Roselle (Hibiscus sabdariffa , Sisal and banana (hybrid , Roselle and banana (hybrid and Roselle and sisal (hybrid are fabricated with bio epoxy resin using molding method. In this work, impact strength of Sisal and banana (hybrid, Roselle and banana (hybridand Roselle and sisal (hybrid composite at dry and wet conditions were studied. Impact test were conducted izod impact testing machine. In this work micro structure of the specimens are scanned by the Scanning Electron Microscope.

  18. Incline impact test for shipping containers - approved Standard 1973

    International Nuclear Information System (INIS)

    This method covers the following procedures for making incline impact tests on loaded shipping containers: Procedure A, to determine the ability of a container to withstand impact stresses; and Procedure B, to determine the ability of a container or interior packing, or both, to provide protection to the contents, when subjected to impact stresses. Either procedure may be used to obtain average results permitting a comparison of different designs of containers of the same size and carrying the same load. These procedures are suitable for testing various types of containers such as boxes, crates, barrels, drums, kegs, or pails made of metal, wood, fiberboard, or combinations of these materials

  19. Full-scale aircraft impact test for evaluatioin of impact force

    International Nuclear Information System (INIS)

    For estimating the global elasto-plastic structural response of critical concrete structures subjected to an aircraft crash, the time dependent impact force of a flat rigid barrier against a normally impacting aircraft was first evaluated and then the response, to the impact force, was calculated. In this approach, a significant problem was to determine the impact force for the aircraft against a rigid target. A review of the method proposed to determine the impact forces showed that all were based on analytical methods. However, in these analytical methods, there were many assumptions and many questions remained to be answered. Because of the uncertainty involved in the analytical prediction of the impact force, a full- scale aircraft impact test was performed and an extensive suite of response measurements was obtained. In this paper, these measurements are analyzed to evaluate the impact force accurately. Also, the results were used to evaluate existing analytical methods for prediction of the impact force. 7 refs., 10 figs

  20. The Impact of IPv6 on Penetration Testing

    NARCIS (Netherlands)

    Ottow, Christiaan; Vliet, van Frank; Boer, de Pieter-Tjerk; Pras, Aiko

    2012-01-01

    In this paper we discuss the impact the use of IPv6 has on remote penetration testing of servers and web applications. Several modifications to the penetration testing process are proposed to accommodate IPv6. Among these modifications are ways of performing fragmentation attacks, host discovery and

  1. Effects of the neutronic irradiation on the impact tests

    International Nuclear Information System (INIS)

    The changes that the Charpy curves suffer when steel is exposed to neutronic fluence are studied. Three steels with different chemical composition were chosen, two of them (JPF and JPJ) being treated at only one neutronic fluence, while the last one (JRQ) was irradiated at three fluences. In this way, it was possible to compare the effect of increasing the neutronic dose, and to study the experimental results as a function of the steel chemical composition. Two characteristic facts have been observed: the displacement of the curve at higher temperatures, and decrease of the upper shelf energy (USE). The mechanical recovery of the materials after two different thermal treatments is also described, and a comparation between the experimental results obtained and the damage prediction formulas given by different regulatory international organisms in the nuclear field is established. Author. 11 refs

  2. Repeated drop weight impacts and post-impact ILSS tests on glass-epoxy composite

    OpenAIRE

    Kishore; Ramanathan, S.; Rao, RMVGK

    1996-01-01

    E glass epoxy laminates of thicknesses in the range 2-5 mm were subjected to repeated impacts. For each thickness the number of hits to cause tup penetration was determined and the value of this number was higher the larger the thickness of the laminate tested. The C-scan, before and after impact, was done to obtain information regarding flaw distribution. Short beam shear test samples were made from locations at fixed distances from impact point and tested. The samples closer to the zone of ...

  3. Taylor impact tests on PBX composites: imaging and analysis

    International Nuclear Information System (INIS)

    A series of Taylor impact tests were performed on three plastic bonded explosive (PBX) formulations: PBX 9501, PBXN-9 and HPP (propellant). The first two formulations are HMX-based, and all three have been characterized quasi-statically in tension and compression. The Taylor impact tests use a 500 psi gas gun to launch PBX projectiles (approximately 30 grams, 16 mm diameter, 76 mm long), velocities as high as 215 m/s, at a steel anvil. Tests were performed remotely and no sign of ignition/reaction have been observed to date. Highspeed imaging was used to capture the impact of the specimen onto anvil surface. Side-view contour images have been analyzed using dynamic stress equations from the literature, and additionally, front-view images have been used to estimate a tensile strain failure criterion for initial specimen fracture. Post-test sieve analysis of specimen debris correlates fragmentation with projectile velocity, and these data show interesting differences between composites. Along with other quasi-static and dynamic measurements, Taylor impact images and fragmentation data provide a useful metric for the calibration or evaluation of intermediate-rate model predictions of PBX constituitive response and failure/fragmentation. Intermediate-rate tests involving other impact configurations are being considered.

  4. The Impact of Personality and Test Conditions on Mathematical Test Performance

    Science.gov (United States)

    Hayes, Heather; Embretson, Susan E.

    2013-01-01

    Online and on-demand tests are increasingly used in assessment. Although the main focus has been cheating and test security (e.g., Selwyn, 2008) the cross-setting equivalence of scores as a function of contrasting test conditions is also an issue that warrants attention. In this study, the impact of environmental and cognitive distractions, as…

  5. Developing the impact testing module with labVIEW

    International Nuclear Information System (INIS)

    Fast Fourier Transformation (FFT) is one of the most useful way to analyze response signal for the purpose of grasping the dynamic characteristics of system. Vibration test using impact hammer is typical and simple experimental method widely used for catching hold of dynamic peculiar characters and modal behaviors of system. In this thesis, impact testing module for NI-PXI equipment is developed. The analyzing and visualizing module are developed with labVIEW tool. A user can see quickly and easily modal shape of system after analyzing acquired data. This developed module will be expected to build up more convenient and serviceable measurement system

  6. Visualizing the impact of prevalence on a diagnostic test

    DEFF Research Database (Denmark)

    Rehling, Michael

    2010-01-01

    positive and false negative). Traditionally, the four test results are given in a 2 by 2 table, and the terms sensitivity, specificity, and predictive values defined. The influence of the prevalence of the disease in question on the relative distribution of the four test results is not obvious. This...... technical note brings a new illustration of the relative distribution of the four test results at prevalence from 0-1. The figure facilitates the understanding of the impact prevalence has on the predictive values of a clinical test....

  7. Impact tests on rubber compression springs for airplane landing gears

    Science.gov (United States)

    Hohenemser, K

    1930-01-01

    The present report gives the results of tests which were made for the purpose of solving the problem of whether diagrams obtained from pressure tests could be conclusive for the determination of the safe impact coefficients. It is first established that the rubber rings adhere firmly to the compression surfaces during deformation. Suggestions are thus obtained for a constructive simplification of the rubber rings. The hysteresis phenomenon is ascribed to external and internal friction forces. A device for falling tests is then described with which the process of shock absorption with rubber rings was tested.

  8. Large Field Photogrammetry Techniques in Aircraft and Spacecraft Impact Testing

    Science.gov (United States)

    Littell, Justin D.

    2010-01-01

    The Landing and Impact Research Facility (LandIR) at NASA Langley Research Center is a 240 ft. high A-frame structure which is used for full-scale crash testing of aircraft and rotorcraft vehicles. Because the LandIR provides a unique capability to introduce impact velocities in the forward and vertical directions, it is also serving as the facility for landing tests on full-scale and sub-scale Orion spacecraft mass simulators. Recently, a three-dimensional photogrammetry system was acquired to assist with the gathering of vehicle flight data before, throughout and after the impact. This data provides the basis for the post-test analysis and data reduction. Experimental setups for pendulum swing tests on vehicles having both forward and vertical velocities can extend to 50 x 50 x 50 foot cubes, while weather, vehicle geometry, and other constraints make each experimental setup unique to each test. This paper will discuss the specific calibration techniques for large fields of views, camera and lens selection, data processing, as well as best practice techniques learned from using the large field of view photogrammetry on a multitude of crash and landing test scenarios unique to the LandIR.

  9. Impact limiter tests of four commonly used materials and establishment of an impact limiter data base

    International Nuclear Information System (INIS)

    In designing a package for transporting hazardous or radioactive materials, there are a number of components whose design can lead to the success or failure to meet regulatory requirements for Type B packages. One of these components is the impact limiter. The primary purpose of the impact limiter is to protect the package and its contents from sudden deceleration. It can also act as a thermal barrier. The package is protected by the impact limiter's ability to act as an energy absorber. The crush strength of most impact limiting materials is determined by a standard quasistatic (QS) method. However it has been observed that there are a number of factors that affect crush strength. The material being used as an impact limiter may appear incompressible because of one or more of these factors. Factors that determine compressive strength of impact limiter materials are; the material density; the thickness of the impact limiter material. There must be adequate material to absorb the impact and not go into lockup, lockup up occurs when the free volume of the material is eliminated and the crush strength sharply increases; the angle of impact; and the loading rate and operating temperature. All of these are interactive and therefore difficult to model. It is the intent of tests discussed in this paper to determine the dependency of crush strength to loading rate and angle of impact to the basic grain direction of two different densities of four impact limiting materials

  10. 16 CFR 1203.11 - Marking the impact test line.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Marking the impact test line. 1203.11 Section 1203.11 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... the helmet on the appropriate headform as specified by the manufacturer's helmet positioning...

  11. Testing of impact resistance of hard nanocomposite coatings

    Czech Academy of Sciences Publication Activity Database

    Fořt, Tomáš; Sobota, Jaroslav; Grossman, Jan

    Brno : Brno University of Technology , Faculty of Mechanical Engineering, 2006 - (Šandera, P.), s. 174-179 ISBN 80-214-3085-0. [NANO´05 – NENAMAT International Conference. Brno (CZ), 08.11.2005-10.11.2005] Institutional research plan: CEZ:AV0Z20650511 Keywords : nanocomposite * coatings * impact * test Subject RIV: JI - Composite Materials

  12. Sloshing roof impact tests of a rectangular tank

    International Nuclear Information System (INIS)

    Some tanks have been damaged at the roofs due to sloshing impact caused by strong earthquakes. It is, therefore, necessary to consider the impact force in the aseismic design code for tank roofs. However, there are few studies on the earthquake responses of storage and process tank roofs. As a first step to investigate the effects of sloshing impact a series of the shaking table tests of a rectangular tank have been conducted at the National Research Institute for Earth Science and Disaster Prevention (NIED). The results of these shaking table tests are presented in the paper. The test tank is rectangular in shape having dimensions of 5 m x 3 m x 2 m length x width x height). The tank was constructed of glass-fiber reinforced plastic panels. Every panel had a flange on four edges, and each panel was connected by bolts along the flange. The test tank was set on the NIED shaking table (15 m by 15 m). Two types of liquid were used, water and a viscous liquid (water mixed with polymeric powders). The roof impact pressures and other quantities were measured. During the tests using the 400 pi El-Centro excitation, the roof deformation sensor steel beam was damaged. The response of side walls with different rigidity were measured in the wall bulging tests. The measured vibrations within the panel plates were larger than those in the panel flanges. The viscous liquid of 100 cp had little influence on wall bulging responses. However, the viscous effects on sloshing responses were observed in the sloshing tests. Approximate analyses of rectangular tanks, considering the influence of static water pressure, are also presented in this paper

  13. Sloshing roof impact tests of a rectangular tank

    Science.gov (United States)

    Minowa, Chikahiro; Ogawa, Nobuyuki; Harada, Iki; Ma, David C.

    Some tanks have been damaged at the roofs due to sloshing impact caused by strong earthquakes. It is, therefore, necessary to consider the impact force in the aseismic design code for tank roofs. However, there are few studies on the earthquake responses of storage and process tank roofs. As a first step to investigate the effects of sloshing impact a series of the shaking table tests of a rectangular tank have been conducted at the National Research Institute for Earth Science and Disaster Prevention (NIED). The results of these shaking table tests are presented in the paper. The test tank is rectangular in shape having dimensions of 5 m x 3 m x 2 m (length x width x height). The tank was constructed of glass-fiber reinforced plastic panels. Every panel had a flange on four edges, and each panel was connected by bolts along the flange. The test tank was set on the NIED shaking table (15 m by 15 m). Two types of liquid were used, water and a viscous liquid (water mixed with polymeric powders). The roof impact pressures and other quantities were measured. During the tests using the 400 pi El-Centro excitation, the roof deformation sensor steel beam was damaged. The response of side walls with different rigidity were measured in the wall bulging tests. The measured vibrations within the panel plates were larger than those in the panel flanges. The viscous liquid of 100 cp had little influence on wall bulging responses. However, the viscous effects on sloshing responses were observed in the sloshing tests. Approximate analyses of rectangular tanks, considering the influence of static water pressure, are also presented in this paper.

  14. Horizontal impact testing of quarter scale flasks using masonry targets

    International Nuclear Information System (INIS)

    The programme leading up to the Train Crash Demonstration included investigation of flask impacts, in horizontal motion, against masonry targets representing abutment structures. An outline is given of a series of eight tests, of which five are described in detail. All the tests used quarter-scale flasks, and the design and construction of the appropriate brick and stone masonry targets is described. A summary of results is given in terms of damage to the model flask compared with the more severe damage seen in regulatory drop tests. (author)

  15. The psychological impact of genetic testing for Alzheimer disease.

    Science.gov (United States)

    Coon, D W; Davies, H; McKibben, C; Gallagher-Thompson, D

    1999-01-01

    Information regarding one's genetic risk for a particular disease might effectively inform medical, financial, and reproductive decisions and perhaps promote established risk reduction behaviors. However, genetic testing may also lead to significant levels of anxiety, depression, or other forms of distress, especially when psychological coping strategies and social reserves are not adequate to manage positive or inconclusive results. This paper focuses on the psychological impact of predisposition genetic for Alzheimer disease (AD). We present stress and coping models that capture the essence of this impact and discuss the potential role of counseling and follow-up interventions. The discussion draws primarily from the experiences of professionals working with other diseases, and seeks to expand that experience into the AD arena. In addition, we emphasize two issues we believe need additional attention in the psychological literature regarding genetic testing and counseling: (i) the psychosocial vulnerability of individuals being tested and, (ii) the sociocultural context of the AD patient and their family members. PMID:10464586

  16. Impact Tensile Testing of Stainless Steels at Various Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    D. K. Morton

    2008-03-01

    Stainless steels are used for the construction of numerous spent nuclear fuel or radioactive material containers that may be subjected to high strains and moderate strain rates during accidental drop events. Mechanical characteristics of these base materials and their welds under dynamic loads in the strain rate range of concern (1 to 300 per second) are not well documented. However, research is being performed at the Idaho National Laboratory to quantify these characteristics. The work presented herein discusses tensile impact testing of dual-marked 304/304L and 316/316L stainless steel material specimens. Both base material and welded material specimens were tested at -20 oF, room temperature, 300 oF, and 600 oF conditions. Utilizing a drop weight impact test machine and 1/4-inch and 1/2-inch thick dog bone-shaped test specimens, a strain rate range of approximately 4 to 40 per second (depending on initial temperature conditions) was achieved. Factors were determined that reflect the amount of increased strain energy the material can absorb due to strain rate effects. Using the factors, elevated true stress-strain curves for these materials at various strain rates and temperatures were generated. By incorporating the strain rate elevated true stress-strain material curves into an inelastic finite element computer program as the defined material input, significant improvement in the accuracy of the computer analyses was attained. However, additional impact testing is necessary to achieve higher strain rates (up to 300 per second) before complete definition of strain rate effects can be made for accidental drop events and other similar energy-limited impulsive loads. This research approach, using impact testing and a total energy analysis methodology to quantify strain rate effects, can be applied to many other materials used in government and industry.

  17. Impact testing of simulated high-level waste glass canisters

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, M.E.; Alzheimer, J.M.; Slate, S.C.

    1985-01-01

    Three Savannah River Laboratory reference high-level waste canisters were subjected to impact tests at the Pacific Northwest Laboratory in Richland, Washington, in June 1983. The purpose of the test was to determine the integrity of the canister, nozzle, and final closure weld and to assess the effects of impacts on the glass. Two of the canisters were fabricated from 304L stainless steel and the third canister from titanium. The titanium canister was subjected to two drops. The first drop was vertical from 9.14 m onto an unyielding surface with the bottom corner of the canister receiving the impact. No failure occurred during this drop. The second drop was vertical from 9.14 m onto an unyielding surface with the corner of the fill nozzle receiving the impact. A large breach in the canister occurred in the region where the fill nozzle joins the dished head. The first stainless steel canister was dropped with the corner of the fill nozzle receiving the impact. The canister showed significant strain with no rupturing in the region where the fill nozzle joins the dished head. The second canister was dropped with the bottom corner receiving the impact and also, dropped horizontally onto an unyielding vertical solid steel cylinder in a puncture test. The bottom drop did not damage the weld and the puncture test did not rupture the canister body. The glass particles in the damaged zone of these canisters were sampled and analyzed for particle size. A comparison was made with control canister in which no impact had occurred. The particle size distribution for the control canisters and the zones of damaged glass were determined down to 1.5 ..mu..m. The quantity of glass fines, smaller than 10 ..mu..m, which must be determined for transportation safety studies, was found to be the largest in the bottom-damaged zone. The total amount of fines smaller than 10 ..mu..m after impact was less than 0.01 wt % of the total amount of glass in the canister.

  18. To improve impact damage response of single and multi-delaminated FRP composites using natural Flax yarn

    International Nuclear Information System (INIS)

    Highlights: ► To study the impact resistance of delaminated composite structures. ► To improve the impact resistance of delaminated composite structures using natural Flax yarn. ► To investigate the effect of z-pinning on the damage process of composite materials. ► To develop FE techniques to model the impact process of composite structures using LSDYNA. -- Abstract: The ply delamination which is known as a principle mode of failure of layered composites due to separation along the interfaces of the layers is one of the main concerns in designing of composite material structures. In this regard, the effect of hybrid laminate lay-up in multi-delaminated composite beam was investigated. The Charpy impact test was chosen to study the energy absorbing capability of delaminated composite beam. Hybrid composite beams were fabricated from combination of glass/epoxy and carbon/epoxy composites. To improve the impact behaviour of multi-delaminated composite beams the laminated hybrid composite beams were pinned using Flax yarns before curing process. It was shown that the multi-delaminated composite beams which are pinned in z-direction are able to arrest the crack propagation and consequently absorb more energy in comparison with simple ones in hybrid composite beams. The Charpy impact test of delaminated composite beams was also simulated by finite element software LS-DYNA and the results were verified with the relevant experimental results.

  19. The effect of strain rate on the impact strength of the high-Mn steel

    Directory of Open Access Journals (Sweden)

    A. Śmiglewicz

    2015-10-01

    Full Text Available In the paper, results of impact bending tests of a high-manganese steel of Fe – 30 wt.%, Mn – 9 wt.%, Al – 0,65 wt.%, C grade are presented. The tests were carried out using a flywheel machine, suitable for dynamic stretching and impact bending tests in the range of linear velocity of the forcing element from 5 ÷ 40 m/s. The obtained test results were compared with the results of impact resistance of the studied steel determined using Charpy machine. Structural investigations were carried out using scanning transmission electron microscopy. Surfaces of fractures formed in the break point during bending tests were analyzed, and they indicate a presence of mixed transcrystalline fractures with a predominance of plastic fractures.

  20. Full-scale tornado-missile impact tests. Interim report

    International Nuclear Information System (INIS)

    Seven completed initial tests are described with 4 types of hypothetical tornado-borne missiles (impacting reinforced concrete panels that are typical of walls in nuclear power facilities). The missiles were rocket propelled to velocities currently postulated as being attainable by debris in tornadoes. (1500-pound 35-foot long utility pole; 8-pound 1-inch Grade 60 reinforcing bar; 78-pound 3-inch Schedule 40 pipe; and 743-pound 12-inch Schedule 40 pipe;) The results show that a minimum thickness of 24 inches is sufficient to prevent backface scabbing from normal impacts of currently postulated tornado missiles and that existing power plant walls are adequate for the most severe conditions currently postulated by regulatory agencies. This report gives selected detailed data on the tests completed thus far, including strain, panel velocity, and reaction histories

  1. Full-scale tornado-missile impact tests. Final report

    International Nuclear Information System (INIS)

    The design of nuclear plant auxiliary building walls and roofs to resist impact from tornado-generated missiles has most recently been based on subscale data and empirical formulae derived from military tests of limited applicability. The test program described in the report provides data from full-scale simulated tornado-missile impacts of reinforced concrete walls that can be used directly for design. In addition, the data can be used to develop improved design and analysis techniques. This project is a part of an interdisciplinary program at EPRI aimed at providing a realistic basis for designing and analyzing nuclear power plants for the effects of hypothetical tornado-borne and in-plant missiles. The objective of the overall program is to ensure plant safety with efficient design

  2. Simulated hail impact testing of photovoltaic solar panels

    Science.gov (United States)

    Moore, D.; Wilson, A.; Ross, R.

    1978-01-01

    Techniques used to simulate and study the effect of hail on photovoltaic solar panels are described. Simulated hail stones (frozen ice spheres projected at terminal velocity) or steel balls were applied by air guns, gravity drop, or static loading. Tests with simulated hail and steel balls yielded different results. The impact strength of 10 commercially available flat-plate photovoltaic modules was tested. It was found that none of the six panel designs incorporating clear potting silicone material as the outermost layer remained undamaged by 1-in. simulated hailstones, while a photovoltaic module equipped with a 0.188-in.-thick acrylic cover sheet would be able to withstand the impact of a 2-in.-diameter hailstone.

  3. Structural response of reduced scale naval structures under impact tests

    OpenAIRE

    Calle M.A.G.; Oshiro R.E.; Mazzariol L.M.; Alves M.

    2014-01-01

    Scaled models are important in naval engineering since actual ship size makes too expensive to test prototypes. However, the analysis of ship collision events employing naval structures in reduced scale is not an ordinary ship research area. The aim of this work is to create the basis for a posterior similarity study by analysing reduced scale ship structures submitted to impact loads. Two basic naval structures, commonly found in the construction of large ships, were considered for this stud...

  4. West Valley Demonstration Project full-scale canister impact tests

    International Nuclear Information System (INIS)

    Five West Valley Nuclear Services (WVNS) high-level waste (HLW) canisters were impact tested during 1994 to demonstrate compliance with the drop test requirements of the Waste Acceptance Product Specifications. The specifications state that the canistered waste form must be able to survive a 7-m (23 ft) drop unbreached. The 10-gauge (0.125 in. wall thickness) stainless steel canisters were approximately 85% filled with simulated vitrified waste and weighed about 2100 kg (4600 lb). Each canister was dropped vertically from a height of 7 m (23 ft) onto an essentially unyielding surface. The integrity of the canister was determined by the application and analysis of strain circles, dimensional measurements, and helium leak testing. The canisters were also visually inspected before and after the drop for physical damage. The results of the impact test verify that the canisters survived the 7-m drops unbreached. Therefore, these results demonstrate that the reference canister meets the drop test specification of the Waste Acceptance Product Specification

  5. Understanding the impact of genetic testing for inherited retinal dystrophy.

    Science.gov (United States)

    Combs, Ryan; McAllister, Marion; Payne, Katherine; Lowndes, Jo; Devery, Sophie; Webster, Andrew R; Downes, Susan M; Moore, Anthony T; Ramsden, Simon; Black, Graeme; Hall, Georgina

    2013-11-01

    The capability of genetic technologies is expanding rapidly in the field of inherited eye disease. New genetic testing approaches will deliver a step change in the ability to diagnose and extend the possibility of targeted treatments. However, evidence is lacking about the benefits of genetic testing to support service planning. Here, we report qualitative data about retinal dystrophy families' experiences of genetic testing in United Kingdom. The data were part of a wider study examining genetic eye service provision. Twenty interviewees from families in which a causative mutation had been identified by a genetic eye clinic were recruited to the study. Fourteen interviewees had chosen to have a genetic test and five had not; one was uncertain. In-depth telephone interviews were conducted allowing a thorough exploration of interviewees' views and experiences of the benefits of genetic counselling and testing. Transcripts were analysed using thematic analysis. Both affected and unaffected interviewees expressed mainly positive views about genetic testing, highlighting benefits such as diagnostic confirmation, risk information, and better preparation for the future. Negative consequences included the burden of knowledge, moral dilemmas around reproduction, and potential impact on insurance. The offer of genetic testing was often taken up, but was felt unnecessary in some cases. Interviewees in the study reported many benefits, suggesting genetic testing should be available to this patient group. The benefits and risks identified will inform future evaluation of models of service delivery. This research was part of a wider study exploring experiences of families with retinal dystrophy. PMID:23403902

  6. Design, analysis, and testing of wood filled impact limiters

    International Nuclear Information System (INIS)

    In current practice, Type B packagings are generally provided with protective covers or impact limiters designed to protect the cask body during impact after the 30 foot free drop regulatory accident. Both the target and the typical shielded cask are essentially rigid. Therefore, the impact limiters must deform or crush in a precisely controlled manner to absorb the kinetic energy without producing excessive inertial loadings or contact forces on the cask body. Transnuclear has found wood to be an ideal energy absorption material for use in impact limiters. Wood has many properties that give it a distinct advantage over other materials. These advantages include: high energy absorption can be achieved per pound of material; large strain can be accommodated before material lockup; a wide selection of material properties is available in different woods; anisotropic behavior (i.e. the crush strength variation with load orientation relative to grain direction) can be used to advantage in local areas of the limiter; properties of wood can be verified before assembly into the limiter (rather than determined afterward as in the case of foam). This paper describes the design, analysis and testing approaches used to develop and verify the performance of wood filled impact limiters for several recent Transnuclear packaging

  7. Sand Impact Tests of a Half-Scale Crew Module Boilerplate Test Article

    Science.gov (United States)

    Vassilakos, Gregory J.; Hardy, Robin C.

    2012-01-01

    Although the Orion Multi-Purpose Crew Vehicle (MPCV) is being designed primarily for water landings, a further investigation of launch abort scenarios reveals the possibility of an onshore landing at Kennedy Space Center (KSC). To gather data for correlation against simulations of beach landing impacts, a series of sand impact tests were conducted at NASA Langley Research Center (LaRC). Both vertical drop tests and swing tests with combined vertical and horizontal velocity were performed onto beds of common construction-grade sand using a geometrically scaled crew module boilerplate test article. The tests were simulated using the explicit, nonlinear, transient dynamic finite element code LS-DYNA. The material models for the sand utilized in the simulations were based on tests of sand specimens. Although the LSDYNA models provided reasonable predictions for peak accelerations, they were not always able to track the response through the duration of the impact. Further improvements to the material model used for the sand were identified based on results from the sand specimen tests.

  8. Machine for development impact tests in sports seats and similar

    Science.gov (United States)

    Gonçalves, R. M.

    2015-10-01

    This paper describes the stages of development of a machine to perform impact tests in sport seats, seats for spectators and multiple seats. This includes reviews and recommendations for testing laboratories that have needs similar to the laboratory where unfolded this process.The machine was originally developed seeking to meet certain impact tests in accordance with the NBR15925 standards; 15878 and 16031. The process initially included the study of the rules and the election of the tests for which the machine could be developed and yet all reports and outcome of interaction with service providers and raw materials.For operating facility, it was necessary to set entirely the machine control, which included the concept of dialogue with operator, the design of the menu screens and the procedures for submission and registration of results. To ensure reliability in the process, the machine has been successfully calibrated according to the requirements of the Brazilian network of calibration.The criticism to this enterprise covers the technical and economic aspects involved and points out the main obstacles that were needed to overcome.

  9. Integrity assessment of TAPS reactor pressure vessel at extended EOL using surveillance test results

    International Nuclear Information System (INIS)

    Integrity assessment of pressure vessels of nuclear reactors (RPV) primarily concentrates on the prevention of brittle failure and conditions are defined under which brittle failure can be excluded. Accordingly, two approaches based on Transition Temperature Concept and Fracture Mechanics Concept were adopted using the impact test results of three credible surveillance data sets obtained from the surveillance specimens of Tarapur Atomic Power Station. RTNDT data towards end of life (EOL) were estimated from the impact test results in accordance with the procedures of USNRC Regulatory Guide 1.99, Rev. 2 and were used as primary input for assessment of the vessel integrity. SA302B (nickel modified) steel cladded with stainless steel is used as the pressure vessel material for the two 210 MWe boiling water reactors of the Tarapur Atomic Power Station (TAPS). The reactors were commissioned during the year 1969. The chemical compositions of SA302B (modified) steel used in fabricating the vessel and the specified tensile property and the Charpy impact property requirements of the steel broadly meet ASME specified requirements. Therefore, the pressure temperature limit curves prescribed by General Electric (G.E.) were compared with those as obtained using procedures of ASME Section XII, Appendix G. The tensile and the Charpy impact properties at 60 EFPY of vessel operation as derived from the surveillance specimens even fulfilled the specified requirements for the virgin material of ASME. Integrity assessment carried out using the two approaches indicated the safety of the vessel for continued operation up to 60 EFPY. (author)

  10. Single and multiple impact ignition of new and aged high explosives in the Steven Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, S K; DePiero, A H; Garza, R G; Tarver, C M

    1999-06-01

    Threshold impact velocities for ignition of exothermic reaction were determined for several new and aged HMX-based solid high explosives using three types of projectiles in the Steven Test. Multiple impact threshold velocities were found to be approximately 10% lower in damaged charges that did not react in one or more prior impacts. Projectiles with protrusions that concentrate the friction work in a small volume of explosive reduced the threshold velocities by approximately 30%. Flat projectiles required nearly twice as high velocities for ignition as rounded projectiles. Blast overpressure gauges were used for both pristine and damaged charges to quantitatively measure reaction violence. Reactive flow calculations of single and multiple impacts with various projectiles suggest that the ignition rates double in damaged charges.

  11. Single and multiple impact ignition of new and aged high explosives in the Steven Impact Test

    International Nuclear Information System (INIS)

    Threshold impact velocities for ignition of exothermic reaction were determined for several new and aged HMX-based solid high explosives using three types of projectiles in the Steven Test. Multiple impact threshold velocities were found to be approximately 10% lower in damaged charges that did not react in one or more prior impacts. Projectiles with protrusions that concentrate the friction work in a small volume of explosive reduced the threshold velocities by approximately 30%. Flat projectiles required nearly twice as high velocities for ignition as rounded projectiles. Blast overpressure gauges were used for both pristine and damaged charges to quantitatively measure reaction violence. Reactive flow calculations of single and multiple impacts with various projectiles suggest that the ignition rates double in damaged charges

  12. Testing and simulation of composite laminates under impact loading

    Science.gov (United States)

    Dang, Xinglai

    Owing to their high stiffness-to-weight and high strength-to-weight ratios, fiber-reinforced polymer-matrix composite laminates are excellent materials for high-performance structures. However, their properties in the thickness direction are very poor as they are weakly bonded by polymeric matrices through laminate interfaces. Accordingly, when a composite laminate is subjected to impact loading, high interlaminar stresses along with the low interlaminar strengths could easily result in interlaminar damage such as delamination. This thesis investigated the response of composite laminates under low-velocity impact and presented numerical techniques for impact simulation. To begin with, instrumented drop-weight impacts ranging from subperforation to perforation levels were introduced to composite laminates having various dimensions and thicknesses. Damaged composite laminates were then subjected to compression-after-impact tests for evaluations of residual properties. Experimental results revealed that perforation was an important damage milestone since impact parameters such as peak force, contact duration, maximum deflection and energy absorption, and residual properties such as compressive stiffness, strength and energy absorption all reached critical levels as perforation took place. It was also found that thickness played a more important role than in-plane dimensions in perforation process. In order to understand more about the relationship between laminate thickness and perforation resistance and to present an economical method to improve perforation resistance, thick laminated composite plates and their assembled counterparts were investigated and compared. An energy profile correlating the impact energy and absorbed energy at all energy levels for each type of composite plates investigated was established and found to be able to address the relationship between energy and damage. Experimental results concluded that increasing thickness was more efficient

  13. Cycom 977-2 Composite Material: Impact Test Results

    Science.gov (United States)

    Engel, Carl D.; Herald, Stephen; Watkins, Casey

    2005-01-01

    The reaction frequency data from 13A testing by MSFC and WSTF appear well behaved for the sample number used by each and exhibit the same type of energy level dependency. The reaction frequency shift in energy level is unexplained at this time. All the 13A data suggest that only a small amount of material is consumed when reactions take place. At ambient pressure, most of not all reactions are quenched as indicated by the small mass loss. As test pressure is increased in LOX using 13B results. Cycom does not support initiation of reactions or propagations of reactions in GOX at 100 psis based on tests at MSFC and WSTF at 72 ft-lb impact energy. No batch effect was identified in LOX or GOX.

  14. Structural response of reduced scale naval structures under impact tests

    Directory of Open Access Journals (Sweden)

    Calle M.A.G.

    2014-01-01

    Full Text Available Scaled models are important in naval engineering since actual ship size makes too expensive to test prototypes. However, the analysis of ship collision events employing naval structures in reduced scale is not an ordinary ship research area. The aim of this work is to create the basis for a posterior similarity study by analysing reduced scale ship structures submitted to impact loads. Two basic naval structures, commonly found in the construction of large ships, were considered for this study: a T cross-section beam submitted to a mid-span impact test and a double plate panel with inner cross reinforcement also submitted to a central impact load. These models were made in a reduced scale of 1:100. The experimental material characterization was also carried out in this work, including the evaluation of the stress strain curve under quasi static conditions, the strain rate sensitivity and the structural failure using three criteria developed particularly for numerical modelling of ship collision by other authors.

  15. Numerical simulation of impact tests on reinforced concrete beams

    International Nuclear Information System (INIS)

    Highlights: ► Predictions using advanced concrete model compare well with the impact test results. ► Several important behavior of concrete is discussed. ► Two mesh ways incorporating rebar into concrete mesh is also discussed. ► Gives a example of using EPDC model and references to develop new constitutive models. -- Abstract: This paper focuses on numerical simulation of impact tests of reinforced concrete (RC) beams by the LS-DYNA finite element (FE) code. In the FE model, the elasto-plastic damage cap (EPDC) model, which is based on continuum damage mechanics in combination with plasticity theory, is used for concrete, and the reinforcement is assumed to be elasto-plastic. The numerical results compares well with the experimental values reported in the literature, in terms of impact force history, mid-span deflection history and crack patterns of RC beams. By comparing the numerical and experimental results, several important behavior of concrete material is investigated, which includes: damage variable to describe the strain softening section of stress–strain curve; the cap surface to describe the plastic volume change; the shape of the meridian and deviatoric plane to describe the yield surface as well as two methods of incorporating rebar into concrete mesh. This study gives a good example of using EPDC model and can be utilized for the development new constitutive models for concrete in future.

  16. Computer-based tests: The impact of test design and problem of equivalency

    Czech Academy of Sciences Publication Activity Database

    Květon, Petr; Jelínek, Martin; Vobořil, Dalibor; Klimusová, H.

    -, č. 23 (2007), s. 32-51. ISSN 0747-5632 R&D Projects: GA ČR(CZ) GA406/99/1052; GA AV ČR(CZ) KSK9058117 Institutional research plan: CEZ:AV0Z7025918 Keywords : Computer-based assessment * speeded test * equivalency Subject RIV: AN - Psychology Impact factor: 1.344, year: 2007

  17. A Blind Test of the Younger Dryas Impact Hypothesis

    Science.gov (United States)

    Holliday, Vance

    2016-01-01

    The Younger Dryas Impact Hypothesis (YDIH) states that North America was devastated by some sort of extraterrestrial event ~12,800 calendar years before present. Two fundamental questions persist in the debate over the YDIH: Can the results of analyses for purported impact indicators be reproduced? And are the indicators unique to the lower YD boundary (YDB), i.e., ~12.8k cal yrs BP? A test reported here presents the results of analyses that address these questions. Two different labs analyzed identical splits of samples collected at, above, and below the ~12.8ka zone at the Lubbock Lake archaeological site (LL) in northwest Texas. Both labs reported similar variation in levels of magnetic micrograins (>300 mg/kg >12.8ka and <11.5ka, but <150 mg/kg 12.8ka to 11.5ka). Analysis for magnetic microspheres in one split, reported elsewhere, produced very low to nonexistent levels throughout the section. In the other split, reported here, the levels of magnetic microspherules and nanodiamonds are low or nonexistent at, below, and above the YDB with the notable exception of a sample <11,500 cal years old. In that sample the claimed impact proxies were recovered at abundances two to four orders of magnitude above that from the other samples. Reproducibility of at least some analyses are problematic. In particular, no standard criteria exist for identification of magnetic spheres. Moreover, the purported impact proxies are not unique to the YDB. PMID:27391147

  18. Impact of Laboratory Test Use Strategies in a Turkish Hospital

    Science.gov (United States)

    Yılmaz, Fatma Meriç; Kahveci, Rabia; Aksoy, Altan; Özer Kucuk, Emine; Akın, Tezcan; Mathew, Joseph Lazar; Meads, Catherine; Zengin, Nurullah

    2016-01-01

    Objectives Eliminating unnecessary laboratory tests is a good way to reduce costs while maintain patient safety. The aim of this study was to define and process strategies to rationalize laboratory use in Ankara Numune Training and Research Hospital (ANH) and calculate potential savings in costs. Methods A collaborative plan was defined by hospital managers; joint meetings with ANHTA and laboratory professors were set; the joint committee invited relevant staff for input, and a laboratory efficiency committee was created. Literature was reviewed systematically to identify strategies used to improve laboratory efficiency. Strategies that would be applicable in local settings were identified for implementation, processed, and the impact on clinical use and costs assessed for 12 months. Results Laboratory use in ANH differed enormously among clinics. Major use was identified in internal medicine. The mean number of tests per patient was 15.8. Unnecessary testing for chloride, folic acid, free prostate specific antigen, hepatitis and HIV testing were observed. Test panel use was pinpointed as the main cause of overuse of the laboratory and the Hospital Information System test ordering page was reorganized. A significant decrease (between 12.6–85.0%) was observed for the tests that were taken to an alternative page on the computer screen. The one year study saving was equivalent to 371,183 US dollars. Conclusion Hospital-based committees including laboratory professionals and clinicians can define hospital based problems and led to a standardized approach to test use that can help clinicians reduce laboratory costs through appropriate use of laboratory tests. PMID:27077653

  19. Verification of constitutive models using the Asay Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Haberman, K.S.; Bennett, J.G.

    1998-09-01

    Accurate analysis and the ability to predict the complete response of particulate composite materials requires accurate inelastic constitutive models. However, to be of maximum utility, these inelastic models must be validated using quantifiable experimental results. The Asay Impact Test is an impact experiment that provides the evolution of the two dimensional in-plane displacement field in a specimen undergoing dynamic inelastic deformation. The experimental displacement field may be directed compared with the predicted displacement field from a candidate inelastic constitutive model. In this paper, the authors report comparisons between experimental and predicted displacement fields in the energetic particulate composite material PBX-9501 during dynamic deformation, and describe the experiment and the constitutive modeling approach.

  20. Estimating Wal-Mart's Impacts in Maryland: A Test of Identification Strategies and Endogeneity Tests

    OpenAIRE

    Michael J. Hicks

    2008-01-01

    In this paper, I estimate the impact of Wal-Mart on labor markets in Maryland. My goal is to compare estimation techniques that incorporate corrections for endogeneity of Wal-Mart's entrance and those that test for and fail to reject exogeneity in Wal-Mart's entrance decision. The instrumental variable approaches I test include those offered by Basker and Neumark et al., and a new test introduced in this paper. I also explain why differences in choice of sample time and location may lead to d...

  1. The DT-19 container design, impact testing and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Aramayo, G.A. [Oak Ridge National Lab., TN (United States); Goins, M.L. [Oak Ridge Y-12 Plant, TN (United States)

    1995-12-01

    Containers used by the Department of Energy (DOE) for the transport of radioactive material components, including components and special assemblies, are required to meet certain impact and thermal requirements that are demonstrated by performance or compliance testing, analytical procedures or a combination of both. The Code of Federal Regulations (CFR) Part 49, Section 173.7(d) stipulates that, {prime}Packages (containers) made by or under direction of the US DOE may be used for the transportation of radioactive materials when evaluated, approved, and certified by the DOE against packaging standards equivalent to those specified in 10 CFR Part 71. This paper describes the details of the design, analysis and testing efforts undertaken to improve the overall structural and thermal integrity of the DC-19 shipping container.

  2. The DT-19 container: Design, impact testing and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Aramayo, G.A.; Goins, M.L.

    1996-07-01

    Containers used by the Department of Energy (DOE) for the transport of radioactive material components, including components and special assemblies, are required to meet certain impact and thermal requirements that are demonstrated by performance or compliance testing, analytical procedures or a combination of both. The Code of Federal Regulations (CFR) Part 49, Section 173.7(d) stipulates that, `Packages (containers) made by or under direction of the U.S. DOE may be used for the transportation of radioactive materials when evaluated, approved, and certified by the DOE against packaging standards equivalent to those specified in 10 CFR Part 71.` This paper describes the details of the design, analysis and testing efforts undertaken to improve the overall structural and thermal integrity of the DC-19 shipping container.

  3. The DT-19 container: Design, impact testing and analysis

    International Nuclear Information System (INIS)

    Containers used by the Department of Energy (DOE) for the transport of radioactive material components, including components and special assemblies, are required to meet certain impact and thermal requirements that are demonstrated by performance or compliance testing, analytical procedures or a combination of both. The Code of Federal Regulations (CFR) Part 49, Section 173.7(d) stipulates that, 'Packages (containers) made by or under direction of the U.S. DOE may be used for the transportation of radioactive materials when evaluated, approved, and certified by the DOE against packaging standards equivalent to those specified in 10 CFR Part 71.' This paper describes the details of the design, analysis and testing efforts undertaken to improve the overall structural and thermal integrity of the DC-19 shipping container

  4. The DT-19 container design, impact testing and analysis

    International Nuclear Information System (INIS)

    Containers used by the Department of Energy (DOE) for the transport of radioactive material components, including components and special assemblies, are required to meet certain impact and thermal requirements that are demonstrated by performance or compliance testing, analytical procedures or a combination of both. The Code of Federal Regulations (CFR) Part 49, Section 173.7(d) stipulates that, 'Packages (containers) made by or under direction of the US DOE may be used for the transportation of radioactive materials when evaluated, approved, and certified by the DOE against packaging standards equivalent to those specified in 10 CFR Part 71. This paper describes the details of the design, analysis and testing efforts undertaken to improve the overall structural and thermal integrity of the DC-19 shipping container

  5. Dynamic Impact Analyses and Tests of Concrete Overpacks - 13638

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sanghoon; Cho, Sang-Soon; Kim, Ki-Young; Jeon, Je-Eon; Seo, Ki-Seog [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-07-01

    Concrete cask is an option for spent nuclear fuel interim storage which is prevailingly used in US. A concrete cask usually consists of metallic canister which confines the spent nuclear fuel and concrete overpack. When the overpack undergoes a severe missile impact which might be caused by a tornado or an aircraft crash, it should sustain acceptable level of structural integrity so that its radiation shielding capability and the retrievability of canister are maintained. Missile impact against a concrete overpack involves two damage modes, local damage and global damage. Local damage of concrete is usually evaluated by empirical formulas while the global damage is evaluated by finite element analysis. In many cases, those two damage modes are evaluated separately. In this research, a series of numerical simulations are performed using finite element analysis to evaluate the global damage of concrete overpack as well as its local damage under high speed missile impact. We consider two types of concrete overpack, one with steel in-cased concrete without reinforcement and the other with partially-confined reinforced concrete. The numerical simulation results are compared with test results and it is shown that appropriate modeling of material failure is crucial in this analysis and the results are highly dependent on the choice of failure parameters. (authors)

  6. Determine an effective golf swing by swing speed and impact precision tests

    OpenAIRE

    Jiann-Jyh Wang; Pei-Feng Yang; Wei-Hua Ho; Tzyy-Yuang Shiang

    2015-01-01

    Background: To understand an effective golf swing, both swing speed and impact precision must be thoroughly and simultaneously examined. The aim of this study was to perform both swing speed test and impact precision test to ascertain what swing type determines an effective impact. Methods: Seven golfers from a college team (handicap: 0–12) were recruited to complete a swing speed test and impact precision test using a 5-iron club. A force plate and electromyography (EMG) system were used ...

  7. IMPROVED BAR IMPACT TESTS USING A PHOTONIC DOPPLER VELOCIMETER

    Energy Technology Data Exchange (ETDEWEB)

    Bless, S J; Tolman, J; Levinson, S; Nguyen, J

    2009-08-24

    Bar impact tests, using the techniques described elsewhere in this symposium, were used to measure compressive and tensile strengths of borosilicate glass, soda lime glass, and a glass ceramic. The glass ceramic was 25% crystalline spinel, furnished by Corning Inc. There are two measures of compressive strength: the peak stress that can be transmitted in unconfined compression, and the 'steady state' strength. For borosilicate glass and soda lime glass, these values were similar, being about 1.8 and 1.5 GPa, respectively. The glass ceramic (25% spinel) was almost 50% stronger. Tensile failure in the glass and glass ceramic takes places via surface flaws, and thus tensile strength is an extrinsic, as opposed to intrinsic property.

  8. Test Directions as a Critical Component of Test Design: Best Practices and the Impact of Examinee Characteristics

    Science.gov (United States)

    Lakin, Joni M.

    2014-01-01

    The purpose of test directions is to familiarize examinees with a test so that they respond to items in the manner intended. However, changes in educational measurement as well as the U.S. student population present new challenges to test directions and increase the impact that differential familiarity could have on the validity of test score…

  9. Effects of Dynamic Strain Hardening Exponent on Abnormal Cleavage Fracture Occurring During Drop Weight Tear Test of API X70 and X80 Linepipe Steels

    Science.gov (United States)

    Kang, Minju; Kim, Hyunmin; Lee, Sunghak; Shin, Sang Yong

    2014-02-01

    In this study, drop weight tear tests (DWTT) were conducted on API X70 and X80 linepipe steels fabricated with various compositions and rolling and cooling conditions in order to correlate the strain hardening with the abnormal cleavage fracture occurring in the hammer-impacted area. Area fractions of fracture modes were measured from fractured DWTT specimens, and the measured data were analyzed in relation to microstructures, Charpy impact energy, and strain hardening. All the steels consisted of fine acicular ferrite, together with some bainitic ferrite, granular bainite, and martensite-austenite constituent. As the volume fraction of acicular ferrite increased, the area fraction of DWTT abnormal cleavage fracture decreased because the toughness of acicular ferrite was higher than other microstructures. The area fraction of abnormal cleavage fracture was weakly related with strain hardening exponents obtained from the quasi-static tensile and compressive tests, but showed better correlation with those obtained from the dynamic compressive test. This tendency could be more clearly observed when steels having similar Charpy impact energy levels were grouped. Since the DWTT was performed under a dynamic loading condition, thus, the abnormal cleavage fracture behavior should be related with the strain hardening analyzed under a dynamic loading condition.

  10. Standard Test Method for Bird Impact Testing of Aerospace Transparent Enclosures

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers conducting bird impact tests under a standard set of conditions by firing a packaged bird at a stationary transparency mounted in a support structure. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 8.

  11. Pendulum type impact test on the partial spacer grid under room and operating temperature conditions

    International Nuclear Information System (INIS)

    The purpose of the dynamic impact test of a spacer grid is to evaluate the lateral impact strength of it for seismic and LOCA, and to estimate scale for the mechanical and structural integrity of the spacer grid. Therefore, the dynamic impact test is performed to estimate the dynamic impact characteristic of a grid by pendulum type impact test. It is executed the room and operating temperature condition for the simulating the active core boundary condition. The initial impact angle is per defined by pre-test and recursively initiated the impact event until occurring the plastic buckling of the grid specimen. The dynamic impact characteristic of a grid is influenced the imposed temperature condition, and the critical impact acceleration of a grid is reduced when the temperature of the specimen is the higher and higher

  12. Conversion Method of Impact Dispersion in Substitute Equivalent Tests Based on Error Propagation

    OpenAIRE

    Gang Wang

    2009-01-01

    Since there are discrepancies of test environment, target and range between substitute equivalent tests and overall operational tests, this study explores a method for converting the impact dispersion of missiles with homing radar from the substitute equivalent test to that in the overall operational test. According to the law of error synthesis, differences between impact dispersion in different tests are decomposed and propagated to the measurement elements of the homing radar by analysing ...

  13. The role of the modified taylor impact test in dynamic material research

    OpenAIRE

    Bagusat Frank; Rohr Ingmar

    2015-01-01

    Dynamic material research with strain rates of more than 1000 1/s is experimentally very often done with a Split-Hopkinson Bar, Taylor impact tests or planar plate impact test investigations. At the Ernst-Mach-Institut (EMI), a variant of an inverted classical Taylor impact test is used by application of velocity interferometers of the VISAR type (“Modified Taylor Impact Test”, MTT). The conduction of the experiments is similar to that of planar plate impact tests. The data reduction and deri...

  14. Test methods for evaluating and comparing the performance of side impact barrier faces

    NARCIS (Netherlands)

    Coo, P.J.A. de; Roberts, A.; Seeck, A.; Cesari, D.

    1998-01-01

    Side-impact safety of passenger cars is assessed in Europe in a full-scale test using a moving barrier. The front of this barrier is deformable and represents the stiffness of an 'average' car. The EU Directive 96/27/EC on side impact protection has adopted the EEVC Side Impact Test Procedure, inclu

  15. Precipitation and impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel during isothermal aging

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jian, E-mail: jh595@uowmail.edu.au [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Li, Huijun [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Barbaro, Frank [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); CBMM Technology Suisse, 14, Rue du Rhone, Geneve 1204 (Switzerland); Jiang, Laizhu [Baoshan Iron and Steel Co., Ltd., Shanghai 200431 (China); Zhu, Zhixiong [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Xu, Haigang; Ma, Li [Baoshan Iron and Steel Co., Ltd., Shanghai 200431 (China)

    2014-08-26

    The effect of isothermal aging on precipitation behaviour and Charpy impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel was investigated by means of Thermo-Calc prediction, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Charpy impact toughness testing. The results show that, niobium, vanadium carbides and nitrides, Fe{sub 2}Nb (Laves phase) and Cr{sub 23}C{sub 6} formed after 2 h aging at 800 °C, and the equilibrium solvus temperature of Fe{sub 2}Nb phase increases to above 750 °C, higher than the calculated temperature (730 °C) using Thermo-Calc. After isothermal aging at 750–950 °C, 2 h aging resulted in a decrease in toughness due to the formation of precipitation, especially (Nb,V)(C,N) and Fe{sub 2}Nb. When isothermally aged at 800 °C for up to 24 h, the coarsening rate of Fe{sub 2}Nb particle is much higher than that of (Nb,V)(C,N), and the impact toughness of the steel is dependent on quantity and sizes of (Nb,V)(C,N) and Fe{sub 2}Nb particles.

  16. Precipitation and impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel during isothermal aging

    International Nuclear Information System (INIS)

    The effect of isothermal aging on precipitation behaviour and Charpy impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel was investigated by means of Thermo-Calc prediction, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Charpy impact toughness testing. The results show that, niobium, vanadium carbides and nitrides, Fe2Nb (Laves phase) and Cr23C6 formed after 2 h aging at 800 °C, and the equilibrium solvus temperature of Fe2Nb phase increases to above 750 °C, higher than the calculated temperature (730 °C) using Thermo-Calc. After isothermal aging at 750–950 °C, 2 h aging resulted in a decrease in toughness due to the formation of precipitation, especially (Nb,V)(C,N) and Fe2Nb. When isothermally aged at 800 °C for up to 24 h, the coarsening rate of Fe2Nb particle is much higher than that of (Nb,V)(C,N), and the impact toughness of the steel is dependent on quantity and sizes of (Nb,V)(C,N) and Fe2Nb particles

  17. Evaluation of impact properties of weld joint of reactor pressure vessel steels with the use of miniaturized specimens

    International Nuclear Information System (INIS)

    The effects of specimen size and location of V-notch on the Charpy impact properties were investigated with different sizes of specimens, standard, CVN-1/2, CVN-1/3, and CVN-1.5 mm, for A533B steel, low Mn, high Cu, high phosphorus (P), and high Cu/P steel weld joint. A part of the specimens was irradiated with neutron at 563 K up to 8x1019 n/cm2. The heat affected zone (HAZ) specimen is the best in the impact properties among the specimens of base metal, HAZ, and weld metal in the steels with 0.003 wt.% P, while it is the worst in the steels with ∼ 0.3 wt.% P. This indicates that the surveillance test of HAZ specimen can be represented by base metal in the case of A533B steels with lower P content (∼ 0.003 wt.%). The effects of notch location and chemical contents on ductile to brittle transition temperature (DBTT) are almost independent of specimen size within an error of ±5 K, indicating that the miniaturized Charpy specimens are applicable and effective in the surveillance tests of reactor pressure vessel steel of extended operation period. After irradiation, the highest DBTT was observed for the specimen with V-notch in base metal in the case of A533B steel and high Cu steel with 0.003 wt.% P. (author)

  18. High-Stakes Standardized Testing & Marginalized Youth: An Examination of the Impact on Those Who Fail

    Science.gov (United States)

    Kearns, Laura-Lee

    2011-01-01

    This study examines the impact of high-stakes, large-scale, standardized literacy testing on youth who have failed the Ontario Secondary School Literacy Test. Interviews with youth indicate that the unintended impact of high-stakes testing is more problematic than policy makers and educators may realize. In contrast to literacy policy's aims to…

  19. The Application of Impact Echo Scanning on Nondestructive Test of Pavement

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new nondestructive test method-Impact Echo Scanning was introduced. Application of this method on pavement structure test was discussed. A method to increase the measurement accuracy of the test on multi-layers was proposed, and was verified by field test. The test results show that the basic structural information can obtained rapidly and accurately by 3-D scanning of the impact echo system.

  20. Simulation and low velocity impact testing on confined explosives

    NARCIS (Netherlands)

    Scholtes, J.H.G.; Verbeek, H.J.

    2010-01-01

    TNO Defence Security and Safety, performs in depth research in energetic material responses to several Insensitive Munitions (IM) stimuli like cook-off, bullet-fragment impact and shaped charge impact. The response of energetic materials to these stimuli depends strongly on the properties of these m

  1. Welding techniques development of CLAM steel for Test Blanket Module

    International Nuclear Information System (INIS)

    Fabrication techniques for Test Blanket Module (TBM) with CLAM are being under development. Effect of surface preparation on the HIP diffusion bonding joints was studied and good joints with Charpy impact absorbed energy close to that of base metal have been obtained. The mechanical properties test showed that effect of HIP process on the mechanical properties of base metal was little. Uniaxial diffusion bonding experiments were carried out to study the effect of temperature on microstructure and mechanical properties. And preliminary experiments on Electron Beam Welding (EBW), Tungsten Inert Gas (TIG) Welding and Laser Beam Welding (LBW) were performed to find proper welding techniques to assemble the TBM. In addition, the thermal processes assessed with a Gleeble thermal-mechanical machine were carried out as well to assist the fusion welding research.

  2. Nevada Test Site, Nye County, Nevada. Final environmental impact statement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-09-01

    This environmental statement for the Nevada Test Site (NTS) considers underground nuclear detonations with yields of one megaton or less, along with the preparations necessary for such detonations. The testing activities considered also include other continuing and intermittent activities, both nuclear and nonnuclear, which can best be conducted in the remote and controlled area of the Nevada Test Site. These activities are listed, with emphasis on weapons testing programs which do not remain static.

  3. Nevada Test Site, Nye County, Nevada. Final environmental impact statement

    International Nuclear Information System (INIS)

    This environmental statement for the Nevada Test Site (NTS) considers underground nuclear detonations with yields of one megaton or less, along with the preparations necessary for such detonations. The testing activities considered also include other continuing and intermittent activities, both nuclear and nonnuclear, which can best be conducted in the remote and controlled area of the Nevada Test Site. These activities are listed, with emphasis on weapons testing programs which do not remain static

  4. Experimental and numerical analysis of Al6063 duralumin using Taylor impact test

    Science.gov (United States)

    Kruszka, L.; Anaszewicz, Ł.; Janiszewski, J.; Grązka, M.

    2012-08-01

    The paper presents results of experimental and numerical analysis of dynamic behaviour Al6063 duralumin. Dynamical experiments were made using Taylor impact test. Experimental results at next step of study were used in numerical analyses of dynamic yield stress of tested material and model parameters of the Johnson-Cook constitutive equation. The main aim of this analysis is to find out dynamical properties of Al6063 duralumin tested in Taylor impact test.

  5. Experimental and numerical analysis of Al6063 duralumin using Taylor impact test

    Directory of Open Access Journals (Sweden)

    Grązka M.

    2012-08-01

    Full Text Available The paper presents results of experimental and numerical analysis of dynamic behaviour Al6063 duralumin. Dynamical experiments were made using Taylor impact test. Experimental results at next step of study were used in numerical analyses of dynamic yield stress of tested material and model parameters of the Johnson–Cook constitutive equation. The main aim of this analysis is to find out dynamical properties of Al6063 duralumin tested in Taylor impact test.

  6. Materials Characterization Center meeting on impact testing of waste forms. Summary report

    International Nuclear Information System (INIS)

    A meeting was held on March 25-26, 1981 to discuss impact test methods for waste form materials to be used in nuclear waste repositories. The purpose of the meeting was to obtain guidance for the Materials Characterization Center (MCC) in preparing the MCC-10 Impact Test Method to be approved by the Materials Review Board. The meeting focused on two essential aspects of the test method, namely the mechanical process, or impact, used to effect rapid fracture of a waste form and the analysis technique(s) used to characterize particulates generated by the impact

  7. Hypervelocity impact testing of non-metallic materials

    Science.gov (United States)

    Schonberg, William P.

    1990-01-01

    A comparative analysis of impact damage in composite and ceramic specimens and in geometrically similar aluminum specimens is performed to determine the advantages and disadvantages of employing certain composite and ceramic materials in the design of structural wall systems for long-duration spacecraft. A similar analysis of the damage in single panel lexan and multi-plane glass windows shows that glass window systems are rather resilent under hypervelocity impact loadings. It is concluded that thin Kevlar 49, IM6/3501-6 graphite/epoxy, and alumina panels offer no advantage over equivalent aluminum 6061-T6 panels in reducing the penetration threat of hypervelocity projectiles.

  8. Satellite Test of Radiation Impact on Ramtron 512K FRAM

    Science.gov (United States)

    MacLeod, Todd C.; Sayyah, Rana; Sims, W. Herb; Varnavas, Kosta A.; Ho, Fat D.

    2009-01-01

    The Memory Test Experiment is a space test of a ferroelectric memory device on a low Earth orbit satellite. The test consists of writing and reading data with a ferroelectric based memory device. Any errors are detected and are stored on board the satellite. The data is send to the ground through telemetry once a day. Analysis of the data can determine the kind of error that was found and will lead to a better understanding of the effects of space radiation on memory systems. The test will be one of the first flight demonstrations of ferroelectric memory in a near polar orbit which allows testing in a varied radiation environment. The memory devices being tested is a Ramtron Inc. 512K memory device. This paper details the goals and purpose of this experiment as well as the development process. The process for analyzing the data to gain the maximum understanding of the performance of the ferroelectric memory device is detailed.

  9. Understanding the impact of genetic testing for inherited retinal dystrophy

    OpenAIRE

    Combs, Ryan; McAllister, Marion; Payne, Katherine; Lowndes, Jo; Devery, Sophie; Webster, Andrew R.; Downes, Susan M; Moore, Anthony T.; Ramsden, Simon; Black, Graeme; Hall, Georgina

    2013-01-01

    The capability of genetic technologies is expanding rapidly in the field of inherited eye disease. New genetic testing approaches will deliver a step change in the ability to diagnose and extend the possibility of targeted treatments. However, evidence is lacking about the benefits of genetic testing to support service planning. Here, we report qualitative data about retinal dystrophy families' experiences of genetic testing in United Kingdom. The data were part of a wider study examining gen...

  10. Tests for determining impact resistance and strength of glass used for nuclear waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Bunnell, L.R.

    1979-05-01

    Tests are described for determining the impact resistance (Section A) and static tensile strength (Section B) of glasses containing simulated or actual nuclear wastes. This report describes the development and use of these tests to rank different glasses, to assess effects of devitrification, and to examine the effect of impact energy on resulting surface area. For clarity this report is divided into two sections, Impact Resistance and Tensile Strength.

  11. Tests for determining impact resistance and strength of glass used for nuclear waste disposal

    International Nuclear Information System (INIS)

    Tests are described for determining the impact resistance (Section A) and static tensile strength (Section B) of glasses containing simulated or actual nuclear wastes. This report describes the development and use of these tests to rank different glasses, to assess effects of devitrification, and to examine the effect of impact energy on resulting surface area. For clarity this report is divided into two sections, Impact Resistance and Tensile Strength

  12. Unconfirmed reactive screening tests and their impact on donor management

    International Nuclear Information System (INIS)

    To determine the percentage of false positive testing for transfusion transmitted infections (TTIs) using immunochromatographic test (ICT) as first line of screening tests and its effect on loss of volunteer blood donors. Over a period of three months, samples from blood bags of donors undergoing phlebotomy at teaching hospital blood banks in Lahore were screened for human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV) by immunochromatographic tests. Those found positive on initial screening were re-tested by ELISA method at the screening laboratory of the Institute of Haematology and Blood Transfusion Service, Punjab. Lahore. Out of a total of 62090 voluntary blood donors, 469 donors were found to be initially reactive for either HIV, HBV or HCV. Amongst these 96 (0.15%) blood donors were found to have tested falsely positive for HIV, HBV or HCV as compared to testing by ELISA. False positive testing rate of 0.15% or 96 out of a total of 62090 donors is rather small in terms of loss of voluntary donors and appropriate utilization of available resources. Although immunochromatographic testing is not the gold standard, however it serves an important purpose of initial donor screening. (author)

  13. Tensile and impact properties of General Atomics 832864 heat of V-4Cr-4Ti alloy

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, H.; Nowicki, L.J.; Gazda, J.; Billone, M.C.; Smith, D.L. [Argonne National Lab., IL (United States); Johnson, W.R.; Trester, P. [General Atomics, San Diego, CA (United States)

    1998-09-01

    A 1300-kg heat of V-4Cr-4Ti alloy was procured by General Atomics (GA) for the DIII-D radiative divertor program. To determine the mechanical properties of this alloy, tensile and Charpy tests were conducted on specimens prepared from pieces of 4.8-mm-thick as-rolled plates, a major product form for the DIII-D application. The tensile tests were conducted at three temperatures, 26, 280 and 380 C, the last two being the anticipated peak temperatures during DIII-D boronization and postvent bake-out, respectively. Results from these tests show that the tensile and impact properties of the 832864 heat are comparable to those of the other smaller V-(4-5)Cr-(4-5)Ti alloy heats previously developed by the US Fusion Materials Program and that scale-up of vanadium alloy production can be successfully achieved as long as reasonable process control is implemented.

  14. The impact of means tested assistance in Southern Europe

    OpenAIRE

    O' Donoghue, Cathal; Albuquerque, J.; Baldini, Massimo; Bargain, Olivier; Bosi, P.; Levy, Horacio; D. Mantovani; Matsaganis, Manos; Mercader-Prats, M.; Farinha, C; Rodrigues, Farinha; Toso, S; Terraz, I.; Tsakloglou, P.

    2002-01-01

    This paper aims to analyse the social assistance systems in five South European countries: France, Greece, Italy, Portugal and Spain. After reviewing the existing system of social assistance in each country, we apply a consistent methodology in order to estimate its impact on income distribution, poverty and target efficiency.

  15. Impact of Educational Level on Performance on Auditory Processing Tests.

    Science.gov (United States)

    Murphy, Cristina F B; Rabelo, Camila M; Silagi, Marcela L; Mansur, Letícia L; Schochat, Eliane

    2016-01-01

    Research has demonstrated that a higher level of education is associated with better performance on cognitive tests among middle-aged and elderly people. However, the effects of education on auditory processing skills have not yet been evaluated. Previous demonstrations of sensory-cognitive interactions in the aging process indicate the potential importance of this topic. Therefore, the primary purpose of this study was to investigate the performance of middle-aged and elderly people with different levels of formal education on auditory processing tests. A total of 177 adults with no evidence of cognitive, psychological or neurological conditions took part in the research. The participants completed a series of auditory assessments, including dichotic digit, frequency pattern and speech-in-noise tests. A working memory test was also performed to investigate the extent to which auditory processing and cognitive performance were associated. The results demonstrated positive but weak correlations between years of schooling and performance on all of the tests applied. The factor "years of schooling" was also one of the best predictors of frequency pattern and speech-in-noise test performance. Additionally, performance on the working memory, frequency pattern and dichotic digit tests was also correlated, suggesting that the influence of educational level on auditory processing performance might be associated with the cognitive demand of the auditory processing tests rather than auditory sensory aspects itself. Longitudinal research is required to investigate the causal relationship between educational level and auditory processing skills. PMID:27013958

  16. Determine an effective golf swing by swing speed and impact precision tests

    Institute of Scientific and Technical Information of China (English)

    Jiann-Jyh Wang; Pei-Feng Yang; Wei-Hua Ho; Tzyy-Yuang Shiang

    2015-01-01

    Background:To understand an effective golf swing, both swing speed and impact precision must be thoroughly and simultaneously examined. The aim of this study was to perform both swing speed test and impact precision test to ascertain what swing type determines an effective impact. Methods:Seven golfers from a college team (handicap:0-12) were recruited to complete a swing speed test and impact precision test using a 5-iron club. A force plate and electromyography (EMG) system were used to collect data in the swing speed test to compare the difference between two motion sequences. High speed video cameras were used to determine the displacement of rotation center for impact precision test. Results: The results showed a significant difference ( p < 0.01) in clubhead speed with different motion sequences and muscle contraction patterns. In the impact precision test, the displacement of the rotation center which defined as the inner center point of the C7 was significantly different ( p<0.05) between different ball impacted marks on club face. Conclusion:The vertical peak ground reaction force on left foot occurring before impact and the left latissimus dorsi contracting prior to the right pectoralis major represent a superior skill by allowing the club to strike the ball with normal collision at a faster speed.

  17. Impact testing and analysis for structural code benchmarking

    International Nuclear Information System (INIS)

    Sandia National Laboratories, in cooperation with industry and other national laboratories, has been benchmarking computer codes used to predict the structural, thermal, criticality, and shielding behavior of radioactive materials packages. The first step in the benchmarking of the codes was to develop standard problem sets and to compare the results from several codes and users. This step for structural analysis codes has been completed as described in Structural Code Benchmarking for the Analysis of Impact Response of Nuclear Material Shipping Casks, R.E. Glass, Sandia National Laboratories, 1985. The problem set is shown in Fig. 1. This problem set exercised the ability of the codes to predict the response to end (axisymmetric) and side (plane strain) impacts with both elastic and elastic/plastic materials. The results from these problems showed that there is good agreement in predicting elastic response. Significant differences occurred in predicting strains for the elastic/plastic models. An example of the variation in predicting plastic behavior is given, which shows the hoop strain as a function of time at the impacting end of Model B. These differences in predicting plastic strains demonstrated a need for benchmark data for a cask-like problem

  18. Testing and Resilience of the Impact Origin of the Moon

    Science.gov (United States)

    Righter, K.; Canup, R. M.

    2016-01-01

    The leading hypothesis for the origin of the Moon is the giant impact model, which grew out of the post-Apollo science community. The hypothesis was able to explain the high E-M system angular momentum, the small lunar core, and consistent with the idea that the early Moon melted substantially. The standard hypothesis requires that the Moon be made entirely from the impactor, strangely at odds with the nearly identical oxygen isotopic composition of the Earth and Moon, compositions that might be expected to be different if Moon came from a distinct impactor. Subsequent geochemical research has highlighted the similarity of both geochemical and isotopic composition of the Earth and Moon, and measured small but significant amounts of volatiles in lunar glassy materials, both of which are seemingly at odds with the standard giant impact model. Here we focus on key geochemical measurements and spacecraft observations that have prompted a healthy re-evaluation of the giant impact model, provide an overview of physical models that are either newly proposed or slightly revised from previous ideas, to explain the new datasets.

  19. IMPACT_S: integrated multiprogram platform to analyze and combine tests of selection.

    Directory of Open Access Journals (Sweden)

    Emanuel Maldonado

    Full Text Available Among the major goals of research in evolutionary biology are the identification of genes targeted by natural selection and understanding how various regimes of evolution affect the fitness of an organism. In particular, adaptive evolution enables organisms to adapt to changing ecological factors such as diet, temperature, habitat, predatory pressures and prey abundance. An integrative approach is crucial for the identification of non-synonymous mutations that introduce radical changes in protein biochemistry and thus in turn influence the structure and function of proteins. Performing such analyses manually is often a time-consuming process, due to the large number of statistical files generated from multiple approaches, especially when assessing numerous taxa and/or large datasets. We present IMPACT_S, an easy-to-use Graphical User Interface (GUI software, which rapidly and effectively integrates, filters and combines results from three widely used programs for assessing the influence of selection: Codeml (PAML package, Datamonkey and TreeSAAP. It enables the identification and tabulation of sites detected by these programs as evolving under the influence of positive, neutral and/or negative selection in protein-coding genes. IMPACT_S further facilitates the automatic mapping of these sites onto the three-dimensional structures of proteins. Other useful tools incorporated in IMPACT_S include Jmol, Archaeopteryx, Gnuplot, PhyML, a built-in Swiss-Model interface and a PDB downloader. The relevance and functionality of IMPACT_S is shown through a case study on the toxicoferan-reptilian Cysteine-rich Secretory Proteins (CRiSPs. IMPACT_S is a platform-independent software released under GPLv3 license, freely available online from http://impact-s.sourceforge.net.

  20. Polynomial cointegration tests of anthropogenic impact on global warming

    OpenAIRE

    Beenstock, M; Y. Reingewertz; N. Paldor

    2012-01-01

    We use statistical methods for nonstationary time series to test the anthropogenic interpretation of global warming (AGW), according to which an increase in atmospheric greenhouse gas concentrations raised global temperature in the 20th century. Specifically, the methodology of polynomial cointegration is used to test AGW since during the observation period (1880–2007) global temperature and solar irradiance are stationary in 1st differences whereas greenhouse gases and aerosol forcing...

  1. Polynomial cointegration tests of anthropogenic impact on global warming

    OpenAIRE

    M. Beenstock; Y. Reingewertz; N. Paldor

    2012-01-01

    We use statistical methods for nonstationary time series to test the anthropogenic interpretation of global warming (AGW), according to which an increase in atmospheric greenhouse gas concentrations raised global temperature in the 20th century. Specifically, the methodology of polynomial cointegration is used to test AGW since during the observation period (1880–2007) global temperature and solar irradiance are stationary in 1st differences, whereas greenhouse gas and aerosol forcings are st...

  2. Impact Testing of Aluminum 2024 and Titanium 6Al-4V for Material Model Development

    Science.gov (United States)

    Pereira, J. Michael; Revilock, Duane M.; Lerch, Bradley A.; Ruggeri, Charles R.

    2013-01-01

    One of the difficulties with developing and verifying accurate impact models is that parameters such as high strain rate material properties, failure modes, static properties, and impact test measurements are often obtained from a variety of different sources using different materials, with little control over consistency among the different sources. In addition there is often a lack of quantitative measurements in impact tests to which the models can be compared. To alleviate some of these problems, a project is underway to develop a consistent set of material property, impact test data and failure analysis for a variety of aircraft materials that can be used to develop improved impact failure and deformation models. This project is jointly funded by the NASA Glenn Research Center and the FAA William J. Hughes Technical Center. Unique features of this set of data are that all material property data and impact test data are obtained using identical material, the test methods and procedures are extensively documented and all of the raw data is available. Four parallel efforts are currently underway: Measurement of material deformation and failure response over a wide range of strain rates and temperatures and failure analysis of material property specimens and impact test articles conducted by The Ohio State University; development of improved numerical modeling techniques for deformation and failure conducted by The George Washington University; impact testing of flat panels and substructures conducted by NASA Glenn Research Center. This report describes impact testing which has been done on aluminum (Al) 2024 and titanium (Ti) 6Al-4vanadium (V) sheet and plate samples of different thicknesses and with different types of projectiles, one a regular cylinder and one with a more complex geometry incorporating features representative of a jet engine fan blade. Data from this testing will be used in validating material models developed under this program. The material

  3. Experimental investigations on dynamic effects in impact notch bending tests

    International Nuclear Information System (INIS)

    The dynamic behaviour of three point bending samples under impact stresses is examined experimentally. Various measuring processes, above all the shadow optics etching process are used. A quasi-static analysis is made by a simple spring/mass model to describe the stress behaviour quantitatively. Based on this, the dynamic effects in model experiments are measured quantitatively with dynamic correction functions and are discussed with reference to the wave processes in the sample. A systematic view of the effect of the many system parameters on the dynamic stress behaviour is obtained. Finally, examples show that the results of this model investigation can be transferred to other experimental conditions. (orig./HP)

  4. Validation of the material point method and plasticity with Taylor impact tests

    CERN Document Server

    Banerjee, Biswajit

    2012-01-01

    Taylor impacts tests were originally devised to determine the dynamic yield strength of materials at moderate strain rates. More recently, such tests have been used extensively to validate numerical codes for the simulation of plastic deformation. In this work, we use the material point method to simulate a number of Taylor impact tests to compare different Johnson-Cook, Mechanical Threshold Stress, and Steinberg-Guinan-Cochran plasticity models and the vob Mises and Gurson-Tvergaard-Needleman yield conditions. In addition to room temperature Taylor tests, high temperature tests have been performed and compared with experimental data.

  5. Impact of peer interaction on conceptual test performance

    CERN Document Server

    Singh, Chandralekha

    2016-01-01

    We analyze the effectiveness of working in pairs on the Conceptual Survey of Electricity and Magnetism test in a calculus-based introductory physics course. Students who collaborated with a peer showed significantly larger normalized gain on individual testing than those who did not collaborate. We did not find statistically significant differences between the performance of students who were given an opportunity to formulate their own response before the peer discussions, compared to those who were not. Peer collaboration also shows evidence for co-construction of knowledge. Discussions with individual students show that students themselves value peer interaction. We discuss the effect of pairing students with different individual achievements.

  6. The Impact of Providing School and Child Test Scores on Educational Markets

    OpenAIRE

    Andrabi, Tahir; Das, Jishnu; Khwaja, Asim Ijaz

    2015-01-01

    This paper studies study the impact of providing school and child test scores on subsequent test scores, prices, and enrollment in markets with multiple public and private providers. A randomly selected half of the sample villages (markets) received report cards. This increased test scores by 0.11 standard deviations, decreased private school fees by 17 percent, and increased primary enrol...

  7. Held Back: The Impact of Curricular and Pedagogical Factors on Tested Achievement in High School Mathematics

    Science.gov (United States)

    Agvanian, Zara

    2013-01-01

    This study examined the impact of curricular factors and teaching practices on students' tested achievement in mathematics, explored the best predictors of the tested achievement, and examined differences in the tested achievement among student subgroups. The study utilized qualitative and quantitative methods and triangulated findings from…

  8. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Somerville, MA (United States); Bergey, Daniel [Building Science Corporation, Somerville, MA (United States)

    2014-02-01

    In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  9. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.; Bergey, D.

    2014-02-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  10. The Impact of Test Anxiety on Test Performance among Iranian EFL Learners

    OpenAIRE

    Minoo Alemi; Parviz Birjandi

    2010-01-01

    As an affective factor, test-taking anxiety has been investigated in different contexts in the
    past two decades. However, the mixed results of the relationship between test-taking anxiety and
    L2 learners’ test performance show that the instrumentation for the assessment of test-taking
    anxiety and the factors comprising the construct of test-taking anxiety trait requires more
    investigation in order to shed more light on the issue. To this e...

  11. The role of the modified taylor impact test in dynamic material research

    Directory of Open Access Journals (Sweden)

    Bagusat Frank

    2015-01-01

    Full Text Available Dynamic material research with strain rates of more than 1000 1/s is experimentally very often done with a Split-Hopkinson Bar, Taylor impact tests or planar plate impact test investigations. At the Ernst-Mach-Institut (EMI, a variant of an inverted classical Taylor impact test is used by application of velocity interferometers of the VISAR type (“Modified Taylor Impact Test”, MTT. The conduction of the experiments is similar to that of planar plate impact tests. The data reduction and derivation of dynamic material data can also be restricted to an analysis of the VISAR signal. Due to these properties, nearly each highly dynamic material characterization in our institute done by planar plate investigations is usually accompanied by MTT experiments. The extended possibilities and usefulness of a combined usage of these two highly dynamic characterization methods are explained. Recently, further developed MTT experiments with very small specimen sizes are presented. For the first time, Taylor impact and planar impact specimen can be used for which the load directions even in case of thin plate test material are identical and not perpendicular to each other. Consequences for testing construction elements are discussed.

  12. The inclined impact test, an efficient method to characterize coatings' cohesion and adhesion properties

    International Nuclear Information System (INIS)

    The impact test, supported by its finite elements method (FEM) simulation, has been successfully used to characterize the fatigue performance of coatings. In this test, the load is exercised perpendicularly to the coated surface by a cemented carbides ball. In the inclined impact test, the successive impacts are applied on an inclined surface. In this way, the coated surfaces are loaded vertically and tangentially simultaneously. The coating fatigue failure modes were classified by means of scanning electron microscopy (SEM) observations and energy dispersive X-ray spectroscopy microanalyses. The experimental method is supported by a developed FEM simulation, which considers the mechanical elastic-plastic properties of the coating and of the substrate, as well as of the ball indenter during the impact test, thus enabling the elucidation of the coating failure modes. In this way, critical equivalent stresses were determined and the coating cohesive and adhesive impact performance was systematically investigated. The inclined impact test implies a new reference to the prediction of the coatings' cohesive and adhesive failure, managing to approach loading directions for a variety of coated surfaces in different applications. Examples for an efficient use of this test are presented and a characteristic magnitude, the coating impact adhesion (CIA), is introduced

  13. Reconsidering the Impact of High-stakes Testing

    Directory of Open Access Journals (Sweden)

    Henry Braun

    2004-01-01

    Full Text Available Over the last fifteen years, many states have implemented high-stakes tests as part of an effort to strengthen accountability for schools, teachers, and students. Predictably, there has been vigorous disagreement regarding the contributions of such policies to increasing test scores and, more importantly, to improving student learning. A recent study by Amrein and Berliner (2002a has received a great deal of media attention. Employing various databases covering the period 1990-2000, the authors conclude that there is no evidence that states that implemented high-stakes tests demonstrated improved student achievement on various external measures such as performance on the SAT, ACT, AP, or NAEP. In a subsequent study in which they conducted a more extensive analysis of state policies (Amrein & Berliner, 2002b, they reach a similar conclusion. However, both their methodology and their findings have been challenged by a number of authors. In this article, we undertake an extended reanalysis of one component of Amrein and Berliner (2002a. We focus on the performance of states, over the period 1992 to 2000, on the NAEP mathematics assessments for grades 4 and 8. In particular, we compare the performance of the high-stakes testing states, as designated by Amrein and Berliner, with the performance of the remaining states (conditioning, of course, on a state’s participation in the relevant NAEP assessments. For each grade, when we examine the relative gains of states over the period, we find that the comparisons strongly favor the high-stakes testing states. Moreover, the results cannot be accounted for by differences between the two groups of states with respect to changes in percent of students excluded from NAEP over the same period. On the other hand, when we follow a particular cohort (grade 4, 1992 to grade 8, 1996 or grade 4, 1996 to grade 8, 2000, we find the comparisons slightly favor the low-stakes testing states, although the discrepancy can

  14. Impact Test as a Tool for Evaluation of Peach Firmness

    Czech Academy of Sciences Publication Activity Database

    Severa, L.; Nedomová, Š.; Buchar, J.; Trnka, Jan; Dvořáková, Pavla

    Lleida : International Society for Horticultural Science, 2012 - (Girona, J.), s. 577-584 ISBN 9789066056152. ISSN 0567-7572. [International Peach Symposium /7./. Lleida (ES), 08.06.2009-11.06.2009] R&D Projects: GA AV ČR IAA201990701 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : penetration test * non-destructive loading * frequency response Subject RIV: GM - Food Processing

  15. The impact of inflation targeting: Testing the good luck hypothesis

    OpenAIRE

    Ravenna, Federico

    2007-01-01

    Over the last twenty years the level and volatility of inflation decreased across industrial countries. The inflation behaviour can be explained by a shift in monetary policy or by a lucky period of low volatility in business cycle shocks. To test theluck hypothesis we examine the inflation experience of Canada, one of the earliest and most successful adopter of an inflation targeting monetary policy. We Kalman-filter the historical structural shocks consistent with an estimated DSGE model, b...

  16. Impact of Laboratory Test Use Strategies in a Turkish Hospital

    OpenAIRE

    Yılmaz, Fatma Meriç; Kahveci, Rabia; AKSOY, Altan; Özer Kucuk, Emine; Akın, Tezcan; Mathew, Joseph Lazar; Meads, Catherine; Zengin, Nurullah

    2016-01-01

    Objectives Eliminating unnecessary laboratory tests is a good way to reduce costs while maintain patient safety. The aim of this study was to define and process strategies to rationalize laboratory use in Ankara Numune Training and Research Hospital (ANH) and calculate potential savings in costs. Methods A collaborative plan was defined by hospital managers; joint meetings with ANHTA and laboratory professors were set; the joint committee invited relevant staff for input, and a laboratory eff...

  17. Measurement of Low Level Explosives Reaction in Gauged Multi-Dimensional Steven Impact Tests

    Energy Technology Data Exchange (ETDEWEB)

    Niles, A M; Garcia, F; Greenwood, D W; Forbes, J W; Tarver, C M; Chidester, S K; Garza, R G; Swizter, L L

    2001-05-31

    The Steven Test was developed to determine relative impact sensitivity of metal encased solid high explosives and also be amenable to two-dimensional modeling. Low level reaction thresholds occur at impact velocities below those required for shock initiation. To assist in understanding this test, multi-dimensional gauge techniques utilizing carbon foil and carbon resistor gauges were used to measure pressure and event times. Carbon resistor gauges indicated late time low level reactions 200-540 {micro}s after projectile impact, creating 0.39-2.00 kb peak shocks centered in PBX 9501 explosives discs and a 0.60 kb peak shock in a LX-04 disk. Steven Test modeling results, based on ignition and growth criteria, are presented for two PBX 9501 scenarios: one with projectile impact velocity just under threshold (51 m/s) and one with projectile impact velocity just over threshold (55 m/s). Modeling results are presented and compared to experimental data.

  18. A portable load cell for in-situ ore impact breakage testing

    OpenAIRE

    Bourgeois, Florent; Banini, George

    2002-01-01

    This paper discusses the design and characterisation of a short, and hence portable impact load cell for in-situ quantification of ore breakage properties under impact loading conditions. Much literature has been published in the past two decades about impact load cells for ore breakage testing. It has been conclusively shown that such machines yield significant quantitative energy-fragmentation information about industrial ores. However, documented load cells are all laboratory systems that ...

  19. Cycom 977-2 Composite Material: Impact Test Results (workshop presentation)

    Science.gov (United States)

    Engle, Carl; Herald, Stephen; Watkins, Casey

    2005-01-01

    Contents include the following: Ambient (13A) tests of Cycom 977-2 impact characteristics by the Brucenton and statistical method at MSFC and WSTF. Repeat (13A) tests of tested Cycom from phase I at MSFC to expended testing statistical database. Conduct high-pressure tests (13B) in liquid oxygen (LOX) and GOX at MSFC and WSTF to determine Cycom reaction characteristics and batch effect. Conduct expended ambient (13A) LOX test at MSFC and high-pressure (13B) testing to determine pressure effects in LOX. Expend 13B GOX database.

  20. 46 CFR 154.605 - Toughness test.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Toughness test. 154.605 Section 154.605 Shipping COAST....605 Toughness test. (a) Each toughness test under §§ 154.610 through 154.625 must meet Subpart 54.05 of this chapter. (b) If subsize test specimens are used for the Charpy V-notch toughness test,...

  1. Ballistic Impact Testing of Aluminum 2024 and Titanium 6Al-4V for Material Model Development

    Science.gov (United States)

    Pereira, J. Michael; Revilock, Duane M.; Ruggeri, Charles R.; Emmerling, William C.; Altobelli, Donald J.

    2012-01-01

    An experimental program is underway to develop a consistent set of material property and impact test data, and failure analysis, for a variety of materials that can be used to develop improved impact failure and deformation models. Unique features of this set of data are that all material property information and impact test results are obtained using identical materials, the test methods and procedures are extensively documented and all of the raw data is available. This report describes ballistic impact testing which has been conducted on aluminum (Al) 2024 and titanium (Ti) 6Al-4vanadium (V) sheet and plate samples of different thicknesses and with different types of projectiles, one a regular cylinder and one with a more complex geometry incorporating features representative of a jet engine fan blade.

  2. Micro-impact testing: A novel nano-/micro-tribological tool for assessing the performance of wear-resistant coatings under impact/fatigue conditions

    Institute of Scientific and Technical Information of China (English)

    BenD.Beake; StephenR.Goodes; JamesF.Smith; AiyangZhang; JishengE.

    2001-01-01

    A novel repetitive contact technique, micro-impact testing, has been developed forcoating evaluation. Impact test results have proved a more consistent measure of coating per-formance under impact/fatigue conditions than traditional tribological methods such as scratch orpin-on-disk testing. The operating principles of the technique are described with some illustrativeresults on hard and soft coatings. The technique can provide information on impact wear resis-tance, susceptibility to brittle fracture, and strength of interfacial adhesion to substrate.

  3. A framework for testing the ability of models to project climate change and its impacts

    DEFF Research Database (Denmark)

    Refsgaard, J. C.; Madsen, H.; Andréassian, V.;

    2014-01-01

    a validation framework and guiding principles applicable across earth science disciplines for testing the capability of models to project future climate change and its impacts. Model test schemes comprising split-sample tests, differential split-sample tests and proxy site tests are discussed in...... relation to their application for projections by use of single models, ensemble modelling and space-time-substitution and in relation to use of different data from historical time series, paleo data and controlled experiments. We recommend that differential-split sample tests should be performed with best......Models used for climate change impact projections are typically not tested for simulation beyond current climate conditions. Since we have no data truly reflecting future conditions, a key challenge in this respect is to rigorously test models using proxies of future conditions. This paper presents...

  4. Impact energy analysis of HSLA specimens after simulated welding thermal cycle

    Directory of Open Access Journals (Sweden)

    Samarždić, I.

    2008-04-01

    Full Text Available This paper presents impact energy results of specimens made from high strength fine grained steel TStE 420 after thermal cycle simulation. These results are obtained by examining Charpy specimens. Metallographic analysis is performed, hardness is measured and total impact energy is divided into ductile and brittle components.

  5. Impact energy analysis of HSLA specimens after simulated welding thermal cycle

    OpenAIRE

    Samarždić, I.; Aračić, S.; Duđner, M.

    2008-01-01

    This paper presents impact energy results of specimens made from high strength fine grained steel TStE 420 after thermal cycle simulation. These results are obtained by examining Charpy specimens. Metallographic analysis is performed, hardness is measured and total impact energy is divided into ductile and brittle components.

  6. A METHOD TO QUANTIFY CRAZING DEFORMATION BY TENSILE TESTS FOR POLYSTYRENE/POLYOLEFIN ELASTOMER IMMISCIBLE BLENDS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A method to quantify crazing deformations by tensile tests for polystyrene (PS) and polyolefin elastomer (POE) blends was investigated. The toughness of PS/POE blends, reflected by the Charpy impact strength, increased with the content of POE. SEM micrographs showed the poor compatibility between PS and POE. In simple tensile tests, it is very easy to achieve the ratio of crazing deformation, I.e. K by measuring the size changes of samples. The K values decreased with increasing the content of POE, and the deformations of PS/POE blends were dominated by crazing. The plots of the change of volume (△V) against longitudinal variation (△l) showed a linear relationship, and the slope of lines decreased with the content of POE. Measuring samples at the tensile velocities of 5 mm/min, 50 mm/min, and 500 mm/min respectively, the K values kept unchanged for each PS/POE blends.

  7. Estimation of fracture toughness of reactor pressure vessel steels using automated ball indentation test

    International Nuclear Information System (INIS)

    The automated ball indentation (ABI) test was utilized to develop a semi-nondestructive method for estimating the fracture toughness (KJC) in the transition temperature range. The key concept of the method is that the indentation deformation energy to the load at which the mean ball-specimen contact pressure reaches the fracture stress is related to the fracture energy of the material. ABI tests were performed for the reactor pressure vessel (RPV) base and weld metals at the temperatures of -150 .deg. C ∼ 0 .deg. C and the fracture toughness (estimated KJC) was calculated from the indentation load-depth data. For all steels the temperature dependence of the estimated fracture toughness was almost the same as that of the ASTM KJC master curve. The reference temperature (To) of the steels were determined from the estimated KJC versus temperature curves. The reference temperature was well correlated with the index temperature of 41J Charpy impact energy (T41J)

  8. A review of the mallet impact test for small scale explosive formulations

    OpenAIRE

    Weaver, M.; Blair, LH; N. Flood; Stennett, C

    2016-01-01

    Development of new explosive formulations begins with the generation of only a few milligrams of material which is investigated using a number of small scale tests such as DSC, TGA, response to flame, mallet impact (mallet friction either glancing or direct blow) to determine whether the formulation is safe to scale up to 10 g. The latter of these tests, mallet impact, can be particularly subjective as the result is directly influenced by the operator carrying out the assessment. Not only can...

  9. Full-scale impact test data for tornado-missile design of nuclear plants

    International Nuclear Information System (INIS)

    It is standard practice to consider the effects of low-probability impacts of tornado-borne debris (''tornado missiles'' such as utility poles and steel pipes) in the structural design of nuclear power plants in the United States. To provide data that can be used directly in the design procedure, a series of full-scale tornado-missile impact tests was performed. This paper is a brief summary of the results and conclusions from these tests. The tests consisted of reinforced concrete panels impacted by poles, pipes, and rods propelled by a rocket sled. The panels were constructed to current minimum standards and had thicknesses typical of auxiliary buildings of nuclear power plants. A specific objective was the determination of the impact velocities below which the panels do not experience backface scabbing. Another objective was to assess the adequacy of (1) conventional design formulae for penetration and scabbing and (2) conventional design methods for overall structural response. Test missiles and velocities represented those in current design standards. Missiles included utility poles, steel pipes, and steel bars. It is important to interpret the data in this paper in recognition that the test conditions represent conservative assumptions regarding maximum wind speeds, injection of the missile into the wind stream, aerodynamic trajectory, and orientation of missile at impact. Even with the severe assumptions made, the full-scale tests described demonstrate the ability of prototypical nuclear plant walls and roofs to provide adequate protection against postulated tornado-missile impact

  10. Procedural development for nuclear waste canister impact testing

    International Nuclear Information System (INIS)

    Double containment requirements for transporting nuclear waste in glass form are costly and may not be necessary for some waste forms. To allow single containment, a procedure for examining particle size distribution and the amount of respirable particles generated under accident conditions was needed. A statistically designed experiment was conducted to examine the effects of glass temperature, fill rate and canister drop orientation upon the amount of sub-ten micron particles generated under simulated accident conditions. Measuring such small particles is somewhat inaccurate because of material loss in handling. By assuming a lognormal particle size distribution, the amount of sub-ten micron particles was estimated from the results for the larger measurable particles. Analyses revealed no temperature or fill rate effect but indicated that the amount of respirable particles is affected by drop orientation. This led to identification of a worst case drop orientation to be used in qualification testing. 4 refs., 2 figs

  11. Fracture mechanisms assessment of a multilayer material with high strength and excellent impact toughness based on the aerospace Al 7075 alloy

    International Nuclear Information System (INIS)

    An aluminium multilayer laminate has been processed by hot rolling. It is constituted by 19 alternated layers of high-strength aluminium alloy (Al 7075-T6, 82 % vol) and thinner pure aluminium layers (Al 1050-H24, 18 % vol). The microstructure of the constituent alloys and the composition gradient across the interfaces has been characterized. The multilayer laminate and the as-received aluminium alloys have been tested at room temperature by Vickers microhardness, three-point bend test and impact Charpy test. The outstanding improvement in damage tolerance, which is 18 times higher than that for the as-received Al 7075 alloy, is due to both intrinsic and extrinsic fracture mechanisms operating in the multilayer laminate during mechanical testing. (Author) 19 refs.

  12. Multisensor data fusion for impact-echo testing of concrete structures

    International Nuclear Information System (INIS)

    Based on the investigation of spatial variations of impact-echo signals for different source and receiver locations, a simple multisensor data fusion strategy is proposed to increase the accuracy of nondestructive evaluation of concrete structures using the impact-echo test. The data fusion strategy fuses the ratios between spectral amplitudes of the delamination and concrete bottom echo signals (D/B ratios) from multiple source–receiver arrays. The fused D/B ratios demonstrate different characteristics for test locations above the delamination, above the sound concrete, and across the delamination boundary. These characteristics can be used to accurately locate the delamination and its boundaries without increasing testing time. The applicability of the multisensor data fusion for impact-echo testing is validated using both numerical simulation and experimental testings. (paper)

  13. Potential clinical impact of normal-tissue intrinsic radiosensitivity testing

    International Nuclear Information System (INIS)

    A critical appraisal is given of the possible benefit from a reliable pre-treatment knowledge of individual normal-tissue sensitivity to radiotherapy. The considerations are in part, but not exclusively, based on the recent experience with in vitro colony-forming assays of the surviving fraction at 2 Gy, the SF2. Three strategies are reviewed: (1) to screen for rare cases with extreme radiosensitivity, so-called over-reactors, and treat these with reduced total dose, (2) to identify the sensitive tail of the distribution of 'normal' radiosensitivities, refer these patients to other treatment, and to escalate the dose to the remaining patients, or (3) to individualize dose prescriptions based on individual radiosensitivity, i.e. treating to isoeffect rather than to a specific dose-fractionation schedule. It is shown that these strategies will have a small, if any, impact on routine radiotherapy. Screening for over-reactors is hampered by the low prevalence of these among otherwise un-selected patients that leads to a low positive predictive value of in vitro radiosensitivity assays. It is argued, that this problem may persist even if the noise on current assays could be reduced to (the unrealistic value of) zero, simply because of the large biological variation in SF2. Removing the sensitive tail of the patient population, will only have a minor effect on the dose that could be delivered to the remaining patients, because of the sigmoid shape of empirical dose-response relationships. Finally, individualizing dose prescriptions based exclusively on information from a normal-tissue radiosensitivity assay, leads to a nearly symmetrical distribution of dose-changes that would produce a very small gain, or even a loss, of tumor control probability if implemented in the clinic. From a theoretical point of view, other strategies could be devised and some of these are considered in this review. Right now the most promising clinical use of in vitro radiosensitivity assays

  14. Conversion Method of Impact Dispersion in Substitute Equivalent Tests Based on Error Propagation

    Directory of Open Access Journals (Sweden)

    Gang Wang

    2009-01-01

    Full Text Available Since there are discrepancies of test environment, target and range between substitute equivalent tests and overall operational tests, this study explores a method for converting the impact dispersion of missiles with homing radar from the substitute equivalent test to that in the overall operational test. According to the law of error synthesis, differences between impact dispersion in different tests are decomposed and propagated to the measurement elements of the homing radar by analysing factors which influence the impact dispersion. Furthermore, the measurement errors in different tests were drawn from their related parameters of radar measurement elements in different tests by analysing the error sources. Then, the different measurement errors were propagated and synthesised into the impact dispersion in different environments. Precision of the conversion process and reliability of the conversion results have also been analysed. Feasibility and effectiveness of this method have been proved in simulation tests.Defence Science Journal, 2009, 59(1, pp.15-21, DOI:http://dx.doi.org/10.14429/dsj.59.1479

  15. High-velocity impact tests involving thin spherical shells of tantalum and 304 stainless steel

    International Nuclear Information System (INIS)

    This experimental program generated data to improve computer-code modeling of impact phenomena. The improved computation technique will be used to design a fissile-material container able to withstand a 335 m/s impact. The program involved flyer-plate-impact tests using thin shells of annealed 304 stainless steel and annealed tantalum at impact velocities of 28 to 180 m/s. No active instrumentation was used in this study; instead, all data were derived from measurements of test specimens. Pre- and post-test measurement of interior and exterior dot patterns etched on the shells provided surface-strain information. Radiographs of the deformed shells provided shell-contour data that we plotted vs impact velocity. Curves were fit to these data. We found that normalized crush height varies almost linearly with impact velocity for both materials, that normalized radius of contact varies directly with impact velocity for both materials but appears independent of shell thickness for tantalum, and that normalized interior-fold radius varies inversely with impact velocity and directly with shell thickness for stainless steel, but no clear relationship appears for tantalum

  16. Determination of anisotropy in impact toughness of aluminium alloy 2024 T3 plate

    Science.gov (United States)

    Siddiqui, M. H.; Hashmi, F.; Junaid, A.

    The research was aimed to quantify the existence of anisotropy in fracture toughness of aluminium alloy 2024 T3 plate (used in aircraft structural members). It was further needed to establish the direction in which the fracture toughness of aluminium alloy 2024 T3 plate is maximum and minimum. This could help ascertain the structural integrity of aircraft structural components; also while designing new components, the knowledge of variation in toughness with respect to direction helps in economizing dead weight of the aircraft. In this research, pursued at the College of Aeronautical Engineering, the anisotropy in toughness of aluminium alloy 2024 T3 plate was analysed using the Charpy V-notch impact toughness test. The effect of specimen orientation on the impact toughness values of the alloy was investigated and compared with known results to verify the reliability of the work and to ascertain the extent of anisotropy in fracture toughness of the said alloy. Charpy impact tests were carried out on ASTM E 23 standard specimens machined at a reference laboratory at room temperature (23° C +/- 2° C). Four different specimen orientations analysed for the purpose of this study were L-S, L-T, T-S and T-L directions. Subsequently, the results obtained at the research centre were then analysed and correlated with morphology of microstructure of the material to establish the reliability of the experimental results. Moreover, an analysis was also done to cater for the possible errors that could affect the fracture toughness values obtained from experimental results. It was concluded that the T-S orientation of the plate had maximum toughness, whereas, minimum toughness was observed in L-T direction.

  17. Testing nanoeffect onto model bacteria: Impact of speciation and genotypes.

    Science.gov (United States)

    Gelabert, Alexandre; Sivry, Yann; Gobbi, Paola; Mansouri-Guilani, Nina; Menguy, Nicolas; Brayner, Roberta; Siron, Valerie; Benedetti, Marc Fabien; Ferrari, Roselyne

    2016-01-01

    The gram-negative bacteria Escherichia coli (E. coli) is a very useful prokaryotic model for testing the toxicity of ZnO nanoparticles (nano-ZnO). This toxicity is often linked to Zn(2+) released from nanoparticles in the culture medium, and nano-ZnO dissolution in different media is clearly established. Here, two model E. coli strains MG1655 and W3110 both descendant from the original K-12 showing slight differences in their genome were submitted to nano-ZnO or Zn(2+) in order 1 > to refine the nano-ZnO toxicity mechanisms to E. coli, and 2 > to investigate whether toxicity resulted from a real "nanoparticle" effect or from the release of Zn(2+) in solution. To do so, both strains were submitted to various concentrations (i.e., 0.1-1 mM) of nano-ZnO or Zn(2+) in Luria Bertani (LB) medium. These toxicity studies take into account the nano-ZnO solubility in the culture medium by specifically monitoring the Zn(2+) release in our experimental systems. In our experimental conditions, differences in tolerance to nano-ZnO or Zn(2+) between both strains were clearly evidenced. W3110 is generally more tolerant to metal than MG1655, the latter showing no real difference in its sensitivity to the two zinc added forms unlike W3110. The differences in behavior between both strains could be attributed to differences in the two genomes as a mutation named "amber" in W3110. Moreover, by using these two closely E. coli strains, a real "nano" effect is here clearly demonstrated providing a model to study the toxicity of ZnO nanoparticles. PMID:26593393

  18. The TOEFL Trump Card: An Investigation of Test Impact in an ESL Classroom

    Science.gov (United States)

    Johnson, Karen E.; Jordan, Stefanie Rehn; Poehner, Matthew E.

    2005-01-01

    Much of the research on the effects of tests on foreign and second-language classrooms has examined the impact or washback effect that commercial/institutional language tests, such as the TOEFL, have on teachers' instructional practices (Hughes, 1998; Wall & Alderson, 1993). Using a case study methodology, this study uncovered the ways in which…

  19. Implications of the impact of prevalence on test thresholds and outcomes: lessons from tuberculosis

    OpenAIRE

    Bentley, Tanya GK; Catanzaro, Antonino; Ganiats, Theodore G

    2012-01-01

    Abstract Background With today’s rapid advances in technology and understanding of disease, more screening and diagnostic tests have become available in a variety of sociodemographic and clinical settings. This analysis quantifies the impact of varying prevalence rates on test performance for given sensitivity and specificity values. Methods Using a worked example of latent tuberculosis...

  20. Adult headform impact tests of three Japanese child bicycle helmets into a vehicle.

    Science.gov (United States)

    Mizuno, Koji; Ito, Daisuke; Yoshida, Ryoichi; Masuda, Hiroyuki; Okada, Hiroshi; Nomura, Mitsunori; Fujii, Chikayo

    2014-12-01

    The head is the body region that most frequently incurs fatal and serious injuries of cyclists in collisions against vehicles. Many research studies investigated helmet effectiveness in preventing head injuries using accident data. In this study, the impact attenuation characteristics of three Japanese child bicycle helmets were examined experimentally in impact tests into a concrete surface and a vehicle. A pedestrian adult headform with and without a Japanese child bicycle helmet was dropped onto a concrete surface and then propelled into a vehicle at 35 km/h in various locations such as the bonnet, roof header, windshield and A-pillar. Accelerations were measured and head injury criterion (HIC) calculated. In the drop tests using the adult headform onto a concrete surface from the height of 1.5m, the HIC for a headform without a child helmet was 6325, and was reduced by around 80% when a child helmet was fitted to the headform. In the impact tests, where the headform was fired into the vehicle at 35 km/h at various locations on a car, the computed acceleration based HIC varied depending on the vehicle impact locations. The HIC was reduced by 10-38% for impacts headforms with a child helmet when the impact was onto a bonnet-top and roof header although the HIC was already less than 1000 in impacts with the headform without a child helmet. Similarly, for impacts into the windshield (where a cyclist's head is most frequently impacted), the HIC using the adult headform without a child helmet was 122; whereas when the adult headform was used with a child helmet, a higher HIC value of more than 850 was recorded. But again, the HIC values are below 1000. In impacts into the A-pillar, the HIC was 4816 for a headform without a child helmet and was reduced by 18-38% for a headform with a child helmet depending on the type of Japanese child helmet used. The tests demonstrated that Japanese child helmets are effective in reducing accelerations and HIC in a drop test using

  1. Impact testing of the H1224A shipping/storage container

    Energy Technology Data Exchange (ETDEWEB)

    Harding, D.C.; Bobbe, J.G.; Stenberg, D.R.; Arviso, M.

    1994-05-01

    H1224A weapons containers have been used for years by the Department of Energy and Department of Defense to transport and store W78 warhead midsections. Although designed to protect these midsections only in low-energy handling drop and impact accidents, a recent transportation risk assessment effort has identified a need to evaluate the container`s ability to protect weapons in higher-energy environments. Four impact tests were performed on H1224A containers with W78 Mod 6c mass mockup midsections inside, onto an essentially unyielding target. Dynamic acceleration and strain levels were recorded during the side-on and end-on impacts, each at 12.2 m/s (40 ft/s) and 38.1 m/s (125 ft/s). Measured peak accelerations experienced by the midsections during lower velocity impacts ranged from 250 to 600 Gs for the end-on impact and 350 to 600 Gs for the side-on impact. Measured peak accelerations of the midsections during the higher velocity impacts ranged from 3,000 to 10,000 Gs for the end-on impact and 8,000 to 10,000 Gs for the side-on impact. Deformations in the H1224A container ranged from minimal to severe buckling and weld tearing. At higher impact velocities, the H1224A container may not provide significant energy absorption for the re-entry vehicle midsection but can provide some confinement of potentially damaged components.

  2. Dynamic finite element method modeling of the upper shelf energy of precracked Charpy specimens of neutron irradiated weld metal 72W

    International Nuclear Information System (INIS)

    Dynamic finite element modeling of the fracture behavior of fatigue-precracked Charpy specimens in both unirradiated and irradiated conditions was performed using a computer code, ABAQUS Explicit, to predict the upper shelf energy of precracked specimens of a given size from experimental data obtained for a different size. A tensile fracture-strain based method for modeling crack extension and propagation was used. It was found that the predicted upper shelf energies of full and half size precracked specimens based on third size data were in reasonable agreement with their respective experimental values. Similar success was achieved for predicting the upper shelf energy of subsize precracked specimens based on full size data

  3. Design of an Impact Test for Estimating the Deformation Energies of Projectiles in Wound Ballistics Studies

    OpenAIRE

    M. Jauhari; Bandyopadhyay, A

    1980-01-01

    The paper suggests an impact test which can be used to evaluate the deformation energies of small arm projectiles. Such an evaluation is of significance in wound ballistics studies while determining the amount of energy actually consumed in causing cavitation. Various sources of error inherent in the test have been discussed and it has been concluded that although approximate, the test can serve the useful purpose of providing a basis for interpreting the energy loss figures in gel on a ratio...

  4. Impact Testing and Analysis of Composites for Aircraft Engine Fan Cases

    Science.gov (United States)

    Roberts, Gary D.; Revilock, Duane M.; Binienda, Wieslaw K.; Nie, Walter Z.; Mackenzie, S. Ben; Todd, Kevin B.

    2002-01-01

    The fan case in a jet engine is a heavy structure because of its size and because of the requirement that it contain a blade released during engine operation. Composite materials offer the potential for reducing the weight of the case. Efficient design, test, and analysis methods are needed to efficiently evaluate the large number of potential composite materials and design concepts. The type of damage expected in a composite case under blade-out conditions was evaluated using a subscale test in which a glass/epoxy composite half-ring target was impacted with a wedge-shaped titanium projectile. Fiber shearing occurred near points of contact between the projectile and target. Delamination and tearing occurred on a larger scale. These damage modes were reproduced in a simpler test in which flat glass/epoxy composites were impacted with a blunt cylindrical projectile. A surface layer of ceramic eliminated fiber shear fracture but did not reduce delamination. Tests on 3D woven carbon/epoxy composites indicated that transverse reinforcement is effective in reducing delamination. A 91 cm (36 in.) diameter full-ring sub-component was proposed for larger scale testing of these and other composite concepts. Explicit, transient, finite element analyses indicated that a full-ring test is needed to simulate complete impact dynamics, but simpler tests using smaller ring sections are adequate when evaluation of initial impact damage is the primary concern.

  5. Fragmentation characteristics analysis of sandstone fragments based on impact rockburst test

    Institute of Scientific and Technical Information of China (English)

    Dongqiao Liu; Dejian Li; Fei Zhao; Chengchao Wang

    2014-01-01

    Impact rockburst test on sandstone samples with a central hole is carried out under true triaxial static loads and vertical dynamic load conditions, and rock fragments after the test are collected. The fragments of sandstone generated from strain rockburst test and uniaxial compression test are also collected. The fragments are weighed and the length, width and thickness of each piece of fragments are measured respectively. The fragment quantities with coarse, medium, fine and micro grains in different size ranges, mass and particles distributions are also analyzed. Then, the fractal dimension of fragments is calculated by the methods of size-frequency, mass-frequency and length-to-thickness ratio-frequency. It is found that the crushing degree of impact rockburst fragments is higher, accompanied with blocky character-istics observably. The mass percentage of small grains, including fine and micro grains, in impact rock-burst test is higher than those in strain rockburst test and uniaxial compression test. Energy dissipation from rockburst tests is more than that from uniaxial compression test, as the quantity of micro grains generated does.

  6. Investigation on impact resistance of steel plate reinforced concrete barriers against aircraft impact. Pt.1: Test program and results

    International Nuclear Information System (INIS)

    Steel plate reinforced concrete (SC) structures composed of concrete and steel plates with headed studs are considered to be more effective than RC structures against aircraft impact. This is due to the effects of the steel plates, especially the rear-face steel plates. Thus, their application to outer walls and roofs of risk-sensitive structures such as nuclear-related structures is expected to mitigate damage to critical components. However, few data have been available to understand and evaluate the complex behavior and damage process of SC panels against an aircraft impact. The objective of this study was to obtain valuable experimental and analytical data essential to investigate and establish a protection design method for SC structures against an aircraft impact. As a first step, impact tests using 1/7.5-scale models were carried out to clarify the damage phenomena caused by an aircraft crash into steel plate reinforced concrete (SC) panels. The results indicated that the steel plate, especially the rear-face plate, has a significant effect in preventing scattering of scabbed concrete debris. It was confirmed that SC panels have much better impact resistant performance than conventional reinforced concrete panels, enabling the thickness of protection panels to be reduced by approximately 30%. (authors)

  7. Determine ISS Soyuz Orbital Module Ballistic Limits for Steel Projectiles Hypervelocity Impact Testing

    Science.gov (United States)

    Lyons, Frankel

    2013-01-01

    A new orbital debris environment model (ORDEM 3.0) defines the density distribution of the debris environment in terms of the fraction of debris that are low-density (plastic), medium-density (aluminum) or high-density (steel) particles. This hypervelocity impact (HVI) program focused on assessing ballistic limits (BLs) for steel projectiles impacting the enhanced Soyuz Orbital Module (OM) micrometeoroid and orbital debris (MMOD) shield configuration. The ballistic limit was defined as the projectile size on the threshold of failure of the OM pressure shell as a function of impact speeds and angle. The enhanced OM shield configuration was first introduced with Soyuz 30S (launched in May 2012) to improve the MMOD protection of Soyuz vehicles docked to the International Space Station (ISS). This test program provides HVI data on U.S. materials similar in composition and density to the Russian materials for the enhanced Soyuz OM shield configuration of the vehicle. Data from this test program was used to update ballistic limit equations used in Soyuz OM penetration risk assessments. The objective of this hypervelocity impact test program was to determine the ballistic limit particle size for 440C stainless steel spherical projectiles on the Soyuz OM shielding at several impact conditions (velocity and angle combinations). This test report was prepared by NASA-JSC/ HVIT, upon completion of tests.

  8. Radiation impact of nuclear weapons tests at the Semipalatinks test site on the population of the Altai region

    International Nuclear Information System (INIS)

    The population of the Altai region was exposed repeatedly to radiation during atmospheric tests of nuclear weapons from 1949 to 1962 and during cratering explosions in 1965. It has now been established that 22 nuclear explosions resulted in transport of radionuclides towards the Altai region. The nuclear explosions of 29 August 1949 alone produced an effective dose exceeding 250 mSv in 44 settlements. In the case of the nuclear explosion of 7 August 1962, the thyroid dose to persons living in a number of settlements was more than a few gray. The impact of the tests on the population of the Altai region has been under study since 1990 (as of 1992 under the ''Semipalatinsk test site/Altai'' State research programme). This study covers: reconstruction of doses from the tests, risk assessment, epidemiological studies, health and demosgraphic studies, and ecological research (radioactive and chemical contamination). The goals of the research are development and realization of the programme of additional measures for health protection and compensation, and environmental and social protection. The nuclear test of 1949 produced the greatest radiation impact. The total collective dose from this test to the population of the region is estimated at approximately 32,000 man·Sv, with about 250,000 individuals receiving a dose of above 5 cSv. The radiation impact from this test on the cohort and population levels was estimated using up-to-date scientific theories about stochastic health effects of ionizing radiation. The goal of the research is to obtain data on the consequences of the tests in order to plan social protection measures as well as future research. An analysis of the medico-ecological situation in the affected and control regions and an epidemiological study are being carried out. Some results of the study are presented in the paper. A concept of social protection for the population affected by the tests has been prepared and serves as the basis for taking

  9. Guidelines for conducting impact tests on shipping packages for radioactive material

    International Nuclear Information System (INIS)

    Federal regulation (10 CFR Part 71) specifies a number of impact conditions (free-drop, penetration, and puncture), under which a package for the transport of radioactive materials must be tested or evaluated to demonstrate compliance with the regulation. This report is a comprehensive guide to the planning and execution of these impact tests. The report identifies the required considerations for both the design, pre-, and post-test inspections of the test model and the measurement, recording, analysis, and reporting of the test data. The report also presents reasons for the requirements, identifies the major difficulties in meeting these requirements, and suggests possible methods to overcome the difficulties. Discussed in substantial detail is the use of scale models and instrumented measurements

  10. Simulated Waste Testing Of Glycolate Impacts On The 2H-Evaporator System

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J.

    2013-08-13

    Glycolic acid is being studied as a total or partial replacement for formic acid in the Defense Waste Processing Facility (DWPF) feed preparation process. After implementation, the recycle stream from DWPF back to the high-level waste tank farm will contain soluble sodium glycolate. Most of the potential impacts of glycolate in the tank farm were addressed via a literature review, but several outstanding issues remained. This report documents the non-radioactive simulant tests impacts of glycolate on storage and evaporation of Savannah River Site high-level waste. The testing for which non-radioactive simulants could be used involved the following: the partitioning of glycolate into the evaporator condensate, the impacts of glycolate on metal solubility, and the impacts of glycolate on the formation and dissolution of sodium aluminosilicate scale within the evaporator. The following are among the conclusions from this work: Evaporator condensate did not contain appreciable amounts of glycolate anion. Of all tests, the highest glycolate concentration in the evaporator condensate was 0.38 mg/L. A significant portion of the tests had glycolate concentration in the condensate at less than the limit of quantification (0.1 mg/L). At ambient conditions, evaporator testing did not show significant effects of glycolate on the soluble components in the evaporator concentrates. Testing with sodalite solids and silicon containing solutions did not show significant effects of glycolate on sodium aluminosilicate formation or dissolution.

  11. Impact Behavior of Recycled Aggregate Concrete Based on Split Hopkinson Pressure Bar Tests

    OpenAIRE

    Yubin Lu; Xing Chen; Xiao Teng; Shu Zhang

    2013-01-01

    This paper presents the experimental results of recycled aggregate concrete (RAC) specimens prepared with five different amounts of recycled coarse aggregate (RCA) (i.e., 0, 25%, 50%, 75%, and 100%) subjected to impact loading based on split Hopkinson pressure bar tests. Strain-rate effects on dynamic compressive strength and critical strain of RAC were studied. Results show that the impact properties of RAC exhibit strong strain-rate dependency and increase approximately linearly with strain...

  12. Review of Evidence of Environmental Impacts of Animal Research and Testing

    Directory of Open Access Journals (Sweden)

    Katherine Groff

    2014-06-01

    Full Text Available Millions of animals are used in research and toxicity testing, including in drug, medical device, chemical, cosmetic, personal care, household, and other product sectors, but the environmental consequences are yet to be adequately addressed. Evidence suggests that their use and disposal, and the associated use of chemicals and supplies, contribute to pollution as well as adverse impacts on biodiversity and public health. The objective of this review is to examine such evidence. The review includes examinations of (1 resources used in animal research; (2 waste production in laboratories; (3 sources of pollution; (4 impacts on laboratory workers’ health; and (5 biodiversity impacts. The clear conclusion from the review is that the environmental implications of animal testing must be acknowledged, reported, and taken into account as another factor in addition to ethical and scientific reasons weighing heavily in favor of moving away from allowing and requiring animal use in research and testing.

  13. Numerical test and evaluating method of impact trend of rock-coal system

    Institute of Scientific and Technical Information of China (English)

    JIANG Jin-quan; CHENG Jia-guo; QU Hua; DONG Jian-jun

    2008-01-01

    The impact trend of rock-coal system was studied by the method of accumulat-ing and releasing of deformation energy and interaction of rock-coal system. The system model of roof-coal-floor was established. Based on the RFPA software, rock fracture process analysis system, the numerical test of deformation, fracture and energy transmis-sion of nonlinear and nonhomogeneous rock-coal system, and the numerical test and evaluating method of impact trend of rock-coal system were achieved. When the same coal seam was in different roof and floor conditions, the fracture process of rock-coal sys-tem can be classified as gradual, sudden and delayed fracture three kinds, and their im-pact trend can be classified as void, intense and medium correspondingly. The rock-coal system's impact trend is evaluated by the system impact index μ and burst expanding forms. The criteria μ are μ<1.0, 1.0≤μ<1.5 and μ≥1.5 when the impact trend is void, in-tense or medium, which are tested and verified by the No.2 and No.4 coal seams in Sun-cun mine.

  14. Impact toughness of high strength low alloy TMT reinforcement ribbed bar

    Indian Academy of Sciences (India)

    Bimal Kumar Panigrahi; Surendra Kumar Jain

    2002-08-01

    Charpy V-notch impact toughness of 600 MPa yield stress TMT rebars alloyed with copper, phosphorus, chromium and molybdenum has been evaluated. Subsize Charpy specimens were machined from the rebar keeping the tempered martensite rim intact. The copper–phosphorus rebar showed toughness of 35 J at room temperature. The toughness of copper–molybdenum and copper–chromium rebars was 52 J. The lower toughness of phosphorus steel is attributed to solid solution strengthening and segregation of phosphorus to grain boundaries. Due to superior corrosion resistance, copper–phosphorus TMT rebar is a candidate material in the construction sector.

  15. Test-retest, retest, and retest: Growth curve models of repeat testing with Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT).

    Science.gov (United States)

    Maerlender, Arthur C; Masterson, Caitlin J; James, Tiffany D; Beckwith, Jonathan; Brolinson, Per Gunner; Crisco, Joe; Duma, Stefan; Flashman, Laura A; Greenwald, Rick; Rowson, Steven; Wilcox, Beth; McAllister, Tom W

    2016-10-01

    Computerized neuropsychological testing has become an important tool in the identification and management of sports-related concussions; however, the psychometric effect of repeat testing has not been studied extensively beyond test-retest statistics. The current study analyzed data from Division I collegiate athletes who completed Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) baseline assessments at four sequential time points that varied over the course of their athletic careers. Administrations were part of a larger National Institutes of Health (NIH) study. Growth curve modeling showed that the two memory composite scores increased significantly with successive administrations: Change in Verbal Memory was best represented with a quadratic model, while a linear model best fit Visual Memory. Visual Motor Speed and Reaction Time composites showed no significant linear or quadratic growth. The results demonstrate the effect of repeated test administrations for memory composite scores, while speed composites were not significantly impacted by repeat testing. Acceptable test-retest reliability was demonstrated for all four composites as well. PMID:27266563

  16. Impact Analyses and Tests of Metal Cask Considering Aircraft Engine Crash - 12308

    International Nuclear Information System (INIS)

    The structural integrity of a dual purpose metal cask currently under development by the Korea Radioactive Waste Management Cooperation (KRMC) is evaluated through analyses and tests under a high-speed missile impact considering the targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from the literature. The missile impact velocity was set at 150 m/s, and two impact orientations were considered. A simplified missile simulating a commercial aircraft engine is designed from an impact load history curve provided in the literature. In the analyses, the focus is on the evaluation of the containment boundary integrity of the metal cask. The analyses results are compared with the results of tests using a 1/3 scale model. The results show very good agreements, and the procedure and methodology adopted in the structural analyses are validated. While the integrity of the cask is maintained in one evaluation where the missile impacts the top side of the free standing cask, the containment boundary is breached in another case in which the missile impacts the center of the cask lid in a perpendicular orientation. A safety assessment using a numerical simulation of an aircraft engine crash into spent nuclear fuel storage systems is performed. A commercially available explicit finite element code is utilized for the dynamic simulation, and the strain rate effect is included in the modeling of the materials used in the target system and missile. The simulation results show very good agreement with the test results. It is noted that this is the first test considering an aircraft crash in Korea. (authors)

  17. Integrated assessment of pedestrian head impact protection in testing secondary safety and autonomous emergency braking.

    Science.gov (United States)

    Searson, D J; Anderson, R W G; Hutchinson, T P

    2014-02-01

    Pedestrian impact testing is used to provide information to the public about the relative level of protection provided by different vehicles to a struck pedestrian. Autonomous Emergency Braking (AEB) is a relatively new technology that aims to reduce the impact speed of such crashes. It is expected that vehicles with AEB will pose less harm to pedestrians, and that the benefit will come about through reductions in the number of collisions and a change in the severity of impacts that will still occur. In this paper, an integration of the assessment of AEB performance and impact performance is proposed based on average injury risk. Average injury risk is calculated using the result of an impact test and a previously published distribution of real world crash speeds. A second published speed distribution is used that accounts for the effects of AEB, and reduced average risks are implied. This principle allows the effects of AEB systems and secondary safety performance to be integrated into a single measure of safety. The results are used to examine the effect of AEB on Euro NCAP and ANCAP assessments using previously published results on the likely effect of AEB. The results show that, given certain assumptions about AEB performance, the addition of AEB is approximately the equivalent of increasing Euro NCAP test performance by one band, which corresponds to an increase in the score of 25% of the maximum. PMID:24246294

  18. Putting social impact assessment to the test as a method for implementing responsible tourism practice

    Energy Technology Data Exchange (ETDEWEB)

    McCombes, Lucy, E-mail: l.mccombes@leedsbeckett.ac.uk [International Centre for Research in Events, Tourism and Hospitality (ICRETH), Leeds Beckett University, Headingley Campus, Macaulay Hall 103, Leeds LS6 3QS (United Kingdom); Vanclay, Frank, E-mail: frank.vanclay@rug.nl [Professor of Cultural Geography, Faculty of Spatial Sciences, University of Groningen, PO Box 800, 9700AV Groningen (Netherlands); Evers, Yvette, E-mail: y.evers@tft-earth.org [The Forest Trust, Chemin de Chantavril 2, 1260 Nyon (Switzerland)

    2015-11-15

    The discourse on the social impacts of tourism needs to shift from the current descriptive critique of tourism to considering what can be done in actual practice to embed the management of tourism's social impacts into the existing planning, product development and operational processes of tourism businesses. A pragmatic approach for designing research methodologies, social management systems and initial actions, which is shaped by the real world operational constraints and existing systems used in the tourism industry, is needed. Our pilot study with a small Bulgarian travel company put social impact assessment (SIA) to the test to see if it could provide this desired approach and assist in implementing responsible tourism development practice, especially in small tourism businesses. Our findings showed that our adapted SIA method has value as a practical method for embedding a responsible tourism approach. While there were some challenges, SIA proved to be effective in assisting the staff of our test case tourism business to better understand their social impacts on their local communities and to identify actions to take. - Highlights: • Pragmatic approach is needed for the responsible management of social impacts of tourism. • Our adapted Social impact Assessment (SIA) method has value as a practical method. • SIA can be embedded into tourism businesses existing ‘ways of doing things’. • We identified challenges and ways to improve our method to better suit small tourism business context.

  19. Dynamic impact testing of hedgehog spines using a dual-arm crash pendulum.

    Science.gov (United States)

    Swift, Nathan B; Hsiung, Bor-Kai; Kennedy, Emily B; Tan, Kwek-Tze

    2016-08-01

    Hedgehog spines are a potential model for impact resistant structures and material. While previous studies have examined static mechanical properties of individual spines, actual collision tests on spines analogous to those observed in the wild have not previously been investigated. In this study, samples of roughly 130 keratin spines were mounted vertically in thin substrates to mimic the natural spine layout on hedgehogs. A weighted crash pendulum was employed to induce and measure the effects of repeated collisions against samples, with the aim to evaluate the influence of various parameters including humidity effect, impact energy, and substrate hardness. Results reveal that softer samples-due to humidity conditioning and/or substrate material used-exhibit greater durability over multiple impacts, while the more rigid samples exhibit greater energy absorption performance at the expense of durability. This trend is exaggerated during high-energy collisions. Comparison of the results to baseline tests with industry standard impact absorbing foam, wherein the spines exhibit similar energy absorption, verifies the dynamic impact absorption capabilities of hedgehog spines and their candidacy as a structural model for engineered impact technology. PMID:27082130

  20. Putting social impact assessment to the test as a method for implementing responsible tourism practice

    International Nuclear Information System (INIS)

    The discourse on the social impacts of tourism needs to shift from the current descriptive critique of tourism to considering what can be done in actual practice to embed the management of tourism's social impacts into the existing planning, product development and operational processes of tourism businesses. A pragmatic approach for designing research methodologies, social management systems and initial actions, which is shaped by the real world operational constraints and existing systems used in the tourism industry, is needed. Our pilot study with a small Bulgarian travel company put social impact assessment (SIA) to the test to see if it could provide this desired approach and assist in implementing responsible tourism development practice, especially in small tourism businesses. Our findings showed that our adapted SIA method has value as a practical method for embedding a responsible tourism approach. While there were some challenges, SIA proved to be effective in assisting the staff of our test case tourism business to better understand their social impacts on their local communities and to identify actions to take. - Highlights: • Pragmatic approach is needed for the responsible management of social impacts of tourism. • Our adapted Social impact Assessment (SIA) method has value as a practical method. • SIA can be embedded into tourism businesses existing ‘ways of doing things’. • We identified challenges and ways to improve our method to better suit small tourism business context

  1. Head impact mechanisms of a child occupant seated in a child restraint system as determined by impact testing.

    Science.gov (United States)

    Yoshida, Ryoichi; Okada, Hiroshi; Nomura, Mitsunori; Mizuno, Koji; Tanaka, Yoshinori; Hosokawa, Naruyuki

    2011-11-01

    In side collision accidents, the head is the most frequently injured body region for child occupants seated in a child restraint system (CRS). Accident analyses show that a child's head can move out of the CRS shell, make hard contact with the vehicle interior, and thus sustain serious injuries. In order to improve child head protection in side collisions, it is necessary to understand the injury mechanism of a child in the CRS whose head makes contact with the vehicle interior. In this research, an SUV-to-car oblique side crash test was conducted to reconstruct such head contacts. A Q3s child dummy was seated in a CRS in the rear seat of the target car. The Q3s child dummy's head moved out beyond the CRS side wing, moved laterally, and made contact with the side window glass and the doorsill. It was demonstrated that the hard head contact, which produced a high HIC value, could occur in side collisions. A series of sled tests was carried out to reproduce the dummy kinematic behavior observed in the SUV-to-car crash test, and the sled test conditions such as sled angle, ECE seat slant angle and velocity-time history that duplicated the kinematic behavior were determined. A parametric study also was conducted with the sled tests; and it was found that the impact angle, harness slack, chest clip, and the CRS side wing shape affected the torso motion and head contact with the vehicle interior. PMID:22869307

  2. A low cost method of testing compression-after-impact strength of composite laminates

    Science.gov (United States)

    Nettles, Alan T.

    1991-01-01

    A method was devised to test the compression strength of composite laminate specimens that are much thinner and wider than other tests require. The specimen can be up to 7.62 cm (3 in) wide and as thin as 1.02 mm (.04 in). The best features of the Illinois Institute of Technology Research Institute (IITRI) fixture are combined with an antibuckling jig developed and used at the University of Dayton Research Institute to obtain a method of compression testing thin, wide test coupons on any 20 kip (or larger) loading frame. Up to 83 pct. less composite material is needed for the test coupons compared to the most commonly used compression-after-impact (CAI) tests, which calls for 48 ply thick (approx. 6.12 mm) test coupons. Another advantage of the new method is that composite coupons of the exact lay-up and thickness of production parts can be tested for CAI strength, thus yielding more meaningful results. This new method was used to compression test 8 and 16 ply laminates of T300/934 carbon/epoxy. These results were compared to those obtained using ASTM standard D 3410-87 (Celanese compression test). CAI testing was performed on IM6/3501-6, IM7/SP500 and IM7/F3900. The new test method and associated fixture work well and is a valuable asset to MSFC's damage tolerance program.

  3. The impact of usability reports and user test observations on developers understanding of usability data

    DEFF Research Database (Denmark)

    Høegh, Rune Thaarup; Nielsen, Christian Monrad; Pedersen, Michael Bach;

    2006-01-01

    A usability evaluation provides a strong and rich basis for understanding and improving the design of user interaction with a software system. Exploiting this evaluation requires feedback that significantly impacts the developers' understanding of usability data about the interaction design of the...... system. This article presents results from an exploratory study of 2 ways of providing feedback from a usability evaluation: observation of user tests and reading usability reports. A case study and a field experiment were used to explore how observation and usability reports impact developers......' understanding of usability data. The results indicate that observation of user tests facilitated a rich understanding of usability problems and created empathy with the users and their work. The usability report had a strong impact on the developers' understanding of specific usability problems and supported a...

  4. Look at the Impact of Two Paralinguistic Element On English Writing from the English Writing Test

    Institute of Scientific and Technical Information of China (English)

    孙贻红

    2015-01-01

    By demonstrating the mistakes made by Chinese students in English writing test,this paper tends to explore the impact of two paralinguistic elements i.e.cultural background and stylistics on English writing so as to penetrate the important role of paralinguistic cognition in Foreign Language Teaching.

  5. Testing of the Impact Load and Tribological Behaviour of W-C:H Hard Composite Coatings

    Czech Academy of Sciences Publication Activity Database

    Fořt, Tomáš; Vítů, T.; Novák, R.; Grossman, Jan; Sobota, Jaroslav

    Taipei : IAMS Academia Sinica, 2008, s. 293. ISBN N. [New Diamond and Nano Carbons /2./ - NDNC 2008. Taipei (TW), 26.05.2008-29.05.2008] R&D Projects: GA MPO 2A-1TP1/031 Institutional research plan: CEZ:AV0Z20650511 Keywords : PVD * DLC * pin-on-disc * friction coefficient * impact test Subject RIV: JI - Composite Materials

  6. The Impact of the 2004 Hurricanes on Florida Comprehensive Assessment Test Scores: Implications for School Counselors

    Science.gov (United States)

    Baggerly, Jennifer; Ferretti, Larissa K.

    2008-01-01

    What is the impact of natural disasters on students' statewide assessment scores? To answer this question, Florida Comprehensive Assessment Test (FCAT) scores of 55,881 students in grades 4 through 10 were analyzed to determine if there were significant decreases after the 2004 hurricanes. Results reveal that there was statistical but no practical…

  7. Low amplitude impact testing and analysis of pristine and aged solid high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, S K; Garza, R; Tarver, C M

    1998-08-17

    The critical impact velocities of 60.1 mm diameter blunt steel projectiles required for ignition of exothermic chemical reaction were determined for heavily confined charges of new and aged (15-30 years) solid HMX-based high explosives. The explosives in order of decreasing impact sensitivity were: PBX 9404; LX-lo; LX-14; PBX 9501; and LX-04. Embedded pressure gauges measured the interior pressure histories. Stockpile aged LX-04 and PBX 9501 from dismantled units were tested and compared to freshly pressed charges. The understanding of explosive aging on impact ignition and other hazards must improve as systems are being deployed longer than their initial estimated lifetimes. The charges that did not react on the first impact were subjected to multiple impacts. While the violence of reaction increased with impact velocity, it remained much lower than that produced by an intentional detonation. Ignition and Growth reactive flow models were developed to predict HMX-based explosive impact sensitivity in other geometries and scenarios.

  8. Effect of forming rate on the impact tensile properties of the steels under crash test

    Directory of Open Access Journals (Sweden)

    M. Grumbach

    2007-01-01

    Full Text Available Purpose: The main objective of this study is to examine the mechanical and metallurgical behaviour of thetailored blanks and base metals for thin sheet steels used in the car industry by using a new type of crash test/impact (ITT. It exposes the effect of forming rate on the toughness of thin welded joints (tailored blanks forInterstitial Free (IFS steels used in the automotive industry.Design/methodology/approach: A special crash test device is used in different temperature and the simulatedcrash tests are performed at a constant speed of 5.52 m/s (strain rate about 250 s−1.Findings: The specimen is submitted to impact tensile test at different temperatures. According to testingtemperature, fracture mode varies: At low temperatures, brittle fracture occurs: Due to stress concentration,fracture always occurs in the notched section. At high temperatures, the specimen fails by ductile fracture.Toughness of the steel sheets (base metals, BM or tailored blanks, TBs after forming at certain levels is wellcompared at different materials and test conditions.Practical implications: This study gives very useful data for the crash test. This is a new conception ofspecimen and of the impact/crash machine. It is easily used in automotive industry for practical and economicreason to give rapid answers to designer and also steel makers for ranking the materials.Originality/value: This research used a new developed test called simplified crash test for evaluating theeffect of forming rate on the toughness of thin welded joints (tailored blanks / mechanical assemblies in highformability steel sheets for stamping submitted to dynamic loads such as experienced in real crash tests.

  9. Measurement of Low Level Explosives Reaction in the Two-Dimensional Steven Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, J.W.; Tarver, C.M.; Chidester, S.K.; Garcia, F.; Greenwood, D.W.; Garza, R.

    2000-10-10

    The two-dimensional Steven impact test has been developed to be reproducible and amenable to computer modeling. This test has a hemispherical projectile traveling at tens of m/s impacting a metal cased explosive target. To assist in the understanding of this safety test, two-dimensional shock wave gauge techniques were used to measure the pressures of a few kilobars and times of reactions less than a millisecond. This work is in accord with a long-term goal to develop two-dimensional shock diagnostic techniques that are more than just time of arrival indicators. Experiments were performed where explosives were impacted at levels below shock initiation levels but caused low level reactions. Carbon foil and carbon resistor pressure gauges were used to measure pressures and time of events. The carbon resistor gauges indicate a late time low level reaction at 350 {micro}s after impact of the hemispherical projectile creating 0.5-6 kb peak shocks at the center of PBX 9501 (HMX/Estane/BDNPA-F; 95/2.5/2.5 wt %) explosive discs. The Steven test calculations are based on an ignition and growth criteria and found that the low level reaction occurs at 335 {micro}s, which is in good agreement with the experimental data. Some additional experiments simulating the Steven impact test were done on a gas gun with carbon foil and constantan strain gauges in a PMMA target. Hydrodynamic calculations can be used to evaluate the gauge performance in these experiments and check the lateral strain measurements.

  10. Design of an Impact Test for Estimating the Deformation Energies of Projectiles in Wound Ballistics Studies

    Directory of Open Access Journals (Sweden)

    M. Jauhari

    1980-04-01

    Full Text Available The paper suggests an impact test which can be used to evaluate the deformation energies of small arm projectiles. Such an evaluation is of significance in wound ballistics studies while determining the amount of energy actually consumed in causing cavitation. Various sources of error inherent in the test have been discussed and it has been concluded that although approximate, the test can serve the useful purpose of providing a basis for interpreting the energy loss figures in gel on a rational and scientific basis.

  11. LX-04 VIOLENCE MEASUREMENTS- STEVEN TESTS IMPACTED BY PROJECTILES SHOT FROM A HOWITZER GUN

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, S K; Vandersall, K S; Switzer, L L; Tarver, C M

    2005-07-18

    Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence.

  12. LX-04 VIOLENCE MEASUREMENTS- STEVEN TESTS IMPACTED BY PROJECTILES SHOT FROM A HOWITZER GUN

    International Nuclear Information System (INIS)

    Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence

  13. High-speed impact test of an air-transportable plutonium nitrate shipping container

    International Nuclear Information System (INIS)

    To obtain information on package response for comparison with other test environments, a high-speed impact test was performed on a modified Federal Republic of Germany 18B plutonium nitrate air-transportable container. The container, modified with reinforcing rings for improved crush resistance around the inner tube assembly, was impacted at a velocity of 137 m/s onto an unyielding surface. Substantial crushing of the foam overpack and extensive deformation of the container cavity occurred, causing release of the liquid surrogate contents from the titanium shipping container. The container damage resulting from the high-speed pulldown test was more severe than that from a 185-m free fall onto a semirigid surface by a similar container or the crush environment produced by a 9-m drop of a 2-Mg block onto the container resting on an unyielding surface

  14. Low-cost dynamic tensile testing

    OpenAIRE

    Schindler, H.; Veidt, M.

    1994-01-01

    This paper reports on the development and first application of a low-cost tensile test method utilizing an instrumented Charpy pendulum. It allows for simple tensile testing at increased loading rates up to 600 s-1 at various temperatures. The stress-strain curve is determined from the measured force history using kinematical and kinetic relations. The first results show that the new technique is very promising to determine the influence of loading rate and temperature on the mechanical prope...

  15. Estimation of integrity of cast-iron cask against impact due to free drop test, (1)

    International Nuclear Information System (INIS)

    Ductile cast iron is examined to use for shipping and storage cask from a economic point of view. However, ductile cast iron is considered to be a brittle material in general. Therefore, it is very important to estimate the integrity of cast iron cask against brittle failure due to impact load at 9 m drop test and 1 m derop test on to pin. So, the F.E.M. analysis which takes nonlinearity of materials into account and the estimation against brittle failure by the method which is proposed in this report were carried out. From the analysis, it is made clear that critical flaw depth (the minimum depth to initiate the brittle failure) is 21.1 mm and 13.1 mm in the case of 9 m drop test and 1 m drop test on to pin respectively. These flaw depth can be detected by ultrasonic test. Then, the cask is assured against brittle failure due to impact load at 9 m drop test and 1 m drop test on to pin. (author)

  16. Implementation & Flight Testing of IMPACT system for Autonomous ISR using Collaborating UAVs with Application to Wild Fire Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SSCI and MIT propose to further develop, implement and test the Integrated Mission Planning & Autonomous Control Technology (IMPACT) system software for...

  17. Comparative analysis by simulating and testing pole impact for hot stamping front crossbeam of automobile

    Institute of Scientific and Technical Information of China (English)

    Ma Fangwu; Yao Zaiqi; Liu Qiang; Wang Xiaona; Zhao Fuquan; Li Fangfang; Lin Jianping

    2012-01-01

    Hot stamping 22MnB5 steel plate with ultra-high strength has been widely used for body structural members in consideration of automobile safety and lightweight. This paper presents a verification program of simulating and testing pole impact in order to verify if the front crossbeam reinforcement assembly can meet the design requirements, reduce the overall vehicle simulation and test cost and shorten the operation period. In the same condition, the simulation proved conforming to the design requirements; however, the bumper cracked at the impacting point in the course of pole impact test. The analysis of the crack by optical microscope, Vickers and scanning electron microscope indicates that mixture of ferrite, bainite and martensite was produced in the weld heat-affected zone of the 340/590DP tow hook holder and the 22MnB5 front crossbeam; therefore, their hardness and mechanical property were reduced obviously, so that they fractured when impacted. No welding process with continuous weld but spot welding or other bonding method may be employed for the reason that the capacity of the 22MnB5 steel plate in the weld heat-affected zone was reduced obvi- ously.

  18. Study on Titanium Alloy TC4 Ballistic Penetration Resistance Part Ⅰ: Ballistic Impact Tests

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao; CHEN Wei; GUAN Yupu; GAO Deping

    2012-01-01

    Ballistic impact test of different-scale casings is an efficient way to demonstrate the casing containment capability at the preliminary design stage of the engine.For the sake of studying the titanium alloy TC4 casing performance,the ballistic tests of flat and curved simulation casing are implemented by using two flat blades of different sizes as the projectile.The impact mechanism and failure of the target are discussed.Impact of the projectile is a highly nonlinear transient process with the large deformation of the target.On the impact,failures of the flat casing and the subscale casing are similar,concluding two parts,the global dishing and localized ductile tearing.The main localized failure mode combines plugging (shear) and petaling (shear) if the projectile perforates or penetrates,while crater (shear) if the projectile rebounds.The ballistic limit equation is verified by the test data and the results show that this empirical equation could be a practical way to estimate the critical velocity.

  19. EVALUATION OF EROSIVE WEAR RESISTANCE OF TiN COATINGS BY A SLURRY JET IMPACT TEST

    OpenAIRE

    Iwai, Y.; Miyajima, T.; Honda, T.; Matsubara, T.; Kanda, K; Hogmark, S

    2006-01-01

    In this paper, it is proposed to use a new type of solid particle impact test (slurry jet) to swiftly evaluate wear properties of thin, single layered or multilayered coatings. By the slurry jet, 1.2 µm alumina particles were impacted at high velocity perpendicular to thin PVD coatings of TiN deposited on high speed steel substrate materials under various substrate temperatures.Since the coatings have a much higher wear resistance than the substrate material, the wear rate increases significa...

  20. Low amplitude impact of PBX 9501: Modified Steven spigot gun tests

    Energy Technology Data Exchange (ETDEWEB)

    Idar, D.J.; Lucht, R.A.; Straight, J.W. [and others

    1998-12-01

    Low-velocity mechanical impact and subsequent high explosive (HE) reaction are of concern in credible accident scenarios involving the handling, transport, and storage of nuclear weapons. Using modified Steven spigot gun tests, the authors have investigated the high-explosive violent-reaction (HEVR) potential of PBX 9501 to low-amplitude insult. Reliable modeling predictions require that one identify the relevant parameters and behavioral responses that are key to the reaction mechanism(s) in PBX 9501. Additional efforts have been targeted at identifying relevant differences in the response between baseline and stockpile-aged PBX 9501 to low-velocity impacts.

  1. HIV tests and new diagnoses declined after california budget cuts, but reallocating funds helped reduce impact.

    Science.gov (United States)

    Leibowitz, Arleen A; Byrnes, Karen; Wynn, Adriane; Farrell, Kevin

    2014-03-01

    Historically, California supplemented federal funding of HIV prevention and testing so that Californians with HIV could become aware of their infection and obtain lifesaving treatment. However, budget deficits in 2009 led the state to eliminate its supplemental funding for HIV prevention. We analyzed the impact of California's HIV resource allocation change between state fiscal years 2009 and 2011. We found that the number of HIV tests declined 19 percent, from 66,629 to 53,760, in local health jurisdictions with high HIV burden. In low-burden jurisdictions, the number of HIV tests declined 90 percent, from 20,302 to 2,116. New diagnoses fell from 2,434 in 2009 to 2,235 in 2011 (calendar years) in high-burden jurisdictions and from 346 to 327 in low-burden ones. California's budget crunch prompted state and local programs to redirect remaining HIV funds from risk reduction education to testing activities. Thus, the impact of the budget cuts on HIV tests and new HIV diagnoses was smaller than might have been expected given the size of the cuts. As California's fiscal outlook improves, we recommend that the state restore supplemental funding for HIV prevention and testing. PMID:24590939

  2. Impact of presymptomatic genetic testing on young adults: a systematic review.

    Science.gov (United States)

    Godino, Lea; Turchetti, Daniela; Jackson, Leigh; Hennessy, Catherine; Skirton, Heather

    2016-04-01

    Presymptomatic and predictive genetic testing should involve a considered choice, which is particularly true when testing is undertaken in early adulthood. Young adults are at a key life stage as they may be developing a career, forming partnerships and potentially becoming parents: presymptomatic testing may affect many facets of their future lives. The aim of this integrative systematic review was to assess factors that influence young adults' or adolescents' choices to have a presymptomatic genetic test and the emotional impact of those choices. Peer-reviewed papers published between January 1993 and December 2014 were searched using eight databases. Of 3373 studies identified, 29 were reviewed in full text: 11 met the inclusion criteria. Thematic analysis was used to identify five major themes: period before testing, experience of genetic counselling, parental involvement in decision-making, impact of test result communication, and living with genetic risk. Many participants grew up with little or no information concerning their genetic risk. The experience of genetic counselling was either reported as an opportunity for discussing problems or associated with feelings of disempowerment. Emotional outcomes of disclosure did not directly correlate with test results: some mutation carriers were relieved to know their status, however, the knowledge they may have passed on the mutation to their children was a common concern. Parents appeared to have exerted pressure on their children during the decision-making process about testing and risk reduction surgery. Health professionals should take into account all these issues to effectively assist young adults in making decisions about presymptomatic genetic testing. PMID:26173961

  3. The effects of shock wave and quasi-traveling wave in the mechanical impact test

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    It is well-known that the numerical value is always larger than the measured value,amounting to many times,if we calculate the stress of the specimen in the impulse test using the NASTRAN and ANSYS (N-A) software.We believe that the impact induces shock wave or quasi-traveling wave in the specimen,which can qualitatively explain the discrepancy of the two values.In order to verify it,the Lax-Friedrichs (L-F) scheme is taken to simulate the transmission of shock wave and quasi-traveling wave in solid.Numerical results show that the action area of the stress wave is small and the action time is very short,so the resulting stress and actual work are not big.In addition,the distribution of the impact values obtained by the numerical simulation is in accordance with the trend of the measured impact values.

  4. Mechanical resistance of UO2 pellet by means of free-fall-impact testing

    International Nuclear Information System (INIS)

    A fuel rod failed during a power transient can be seen in Fig 1. and conjunction of a chipped pellet with a cladding crack has been observed in commercial reactors through the post-irradiation examinations. It revealed that missing-pellet-surface(MPS) was one of the reasons of the fuel failure. The mechanism of this failure mode that MPS induces the asymmetry of the pellet-cladding mechanical system mainly comprises a stress concentration at the inner surface resulting in non-classical PCI. The fracture toughness is largely close to material property. It is assumed that by optimizing surface design of UO2 pellet, the strength arises because theoretical strength is considerably affected by geometry as one of a parameter of factor 'f'. Pellet research for design optimization to achieve better resistance to external load should be accompanied with volumetric approach to the improvement of mechanical behavior of pellet being still ongoing. At this work, the resistance to external load is analyzed varying with the geometry of pellets and angles of impact on UO2 pellet surface by the free-fall-impact test method. The tested specimens were equivalently produced and sintered for having the same volumetric property such as sinter density and grain size expect the surface with different geometry design at the end face and shoulder which includes dish, chamfer and land in dimension and angle. Missing-pellet-surface(MPS) on UO2 pellet is inevitable behavior during manufacturing, handling and burning in reactor and brings about non-classical PCI behavior that could damage fuel rod integrity. For this reason, the free-fall-drop tester was developed by KEPCO NF Material Development laboratory in Daejeon for quantitatively investigating the mechanical behavior of UO2. The free-fall-impact test is performed by dropping hammer on pellet shoulder with certain impact energy and at various angles. The result is quantitatively measured with weighing chipped debris. Two types

  5. Implications of the impact of prevalence on test thresholds and outcomes: lessons from tuberculosis

    Directory of Open Access Journals (Sweden)

    Bentley Tanya GK

    2012-10-01

    Full Text Available Abstract Background With today’s rapid advances in technology and understanding of disease, more screening and diagnostic tests have become available in a variety of sociodemographic and clinical settings. This analysis quantifies the impact of varying prevalence rates on test performance for given sensitivity and specificity values. Methods Using a worked example of latent tuberculosis infection, we compared true-positive (TP and false-positive (FP results when varying prevalence and test sensitivity and specificity. We used estimates from published literature to estimate two tests’ sensitivity (81%, QuantiFERON®-TB Gold In-Tube; 88%, T-SPOT®.TB and specificity (99%; 88%, and we used World Health Organization data to estimate disease prevalence in five countries. Results Varying sensitivity impacted outcomes most in high-prevalence settings; change in specificity had greater impact in low-prevalence settings. In switching from QuantiFERON-TB to T-SPOT.TB (higher sensitivity, lower specificity, trade-offs between increasing case identification (TPs and decreasing unnecessary treatments (FPs varied dramatically with prevalence. Lower-prevalence settings paid a greater “price” of more FPs for each TP gained, with 37.7 FPs per TP in the United States (5% prevalence versus 2.5 in the Ivory Coast (55% prevalence. Conclusions Prevalence affects test performance for given sensitivity and specificity values. To optimize test performance, disease prevalence should be incorporated in testing decisions, and sensitivity and specificity should be set locally, not globally. In lower-prevalence settings, using highly specific assays may optimize outcomes.

  6. Threshold Studies on TNT, Composition B, and C-4 Explosives Using the Steven Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, K S; Switzer, L L; Garcia, F

    2005-09-26

    Steven Impact Tests were performed at low velocity on the explosives TNT, Comp B, and C-4 in attempts to obtain a threshold for reaction. A 76 mm helium driven gas gun was used to accelerate the Steven Test projectiles up to approximately 200 m/s in attempts to react (ignite) the explosive samples. Blast overpressure gauges, acoustic microphones, standard video and high-speed photography were used to characterize the level of any high explosive reaction violence. No bulk reactions were observed in the TNT, Composition B, or C-4 explosive samples impacted up to velocities in the range of 190-200 m/s. This work will outline the experimental details and discuss the lack of reaction when compared to the reaction thresholds of other common explosives.

  7. Experimental and Modeling Studies of Crush, Puncture, and Perforation Scenarios in the Steven Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, K S; Chidester, S K; Forbes, J W; Garcia, F; Greenwood, D W; Switzer, L L; Tarver, C M

    2002-06-28

    The Steven test and associated modeling has greatly increased the fundamental knowledge of practical predictions of impact safety hazards for confined and unconfined explosive charges. Building on a database of initial work, experimental and modeling studies of crush, puncture, and perforation scenarios were investigated using the Steven impact test. The descriptions of crush, puncture, and perforation arose from safety scenarios represented by projectile designs that ''crush'' the energetic material or either ''puncture'' with a pinpoint nose or ''perforate'' the front cover with a transportation hook. As desired, these scenarios offer different aspects of the known mechanisms that control ignition: friction, shear and strain. Studies of aged and previously damaged HMX-based high explosives included the use of embedded carbon foil and carbon resistor gauges, high-speed cameras, and blast wave gauges to determine the pressure histories, time required for an explosive reaction, and the relative violence of those reactions, respectively. Various ignition processes were modeled as the initial reaction rate expression in the Ignition and Growth reaction rate equations. Good agreement with measured threshold velocities, pressure histories, and times to reaction was calculated for LX-04 impacted by several projectile geometries using a compression dependent ignition term and an elastic-plastic model with a reasonable yield strength for impact strain rates.

  8. Test and analysis on impact characteristics evaluation of nuclear fuel packaging loaded on vehicle

    International Nuclear Information System (INIS)

    The characteristics of impact to transport containers were clarified by collision test and analysis in the case of small packagings, such as UO2 powder transport containers, that are loaded in plural numbers and by theoretical analysis using a spring-mass model of particles model in the case of large packagings, such as the new fuel assembly, that can be handled singly and independently. Principal characteristics are as follows: (1) The crush impact acceleration of containers is about 1/10 approx. 1/3 of 9-m free drop acceleration; (2) the crush impact loading of containers is observed to be smaller than 9-m free drop loading due to the secured buffer absorption. Therefore the crush impact deformation of containers is smaller than the 9-m free drop deformation. Finally, it has been proved that the UO2 powder container is safe at 50 km/h collision in the way of transportation with buffer after confirming the safety of the container by the drop test prescribed in technical standards (regulations). 10 figures, 2 tables

  9. The Design of Impact Test-Bed for High-Flow Water Medium Relief Valve

    OpenAIRE

    Junliang Chang; Lei Liu; Jiyun Zhao; Haigang Ding; Gaoliang Shi

    2014-01-01

    Water medium hydraulic systems are widely used in coal mining machinery. As the power of hydraulic system becomes higher, the flow and pressure of water medium relief valve are also higher, and the flow may reach 2000 L/min. However, there is no relevant test-bed which could provide instantaneous high-pressure and high-flow to support the experiment for high-flow relief valve; consequently, this impact test-bed for high-flow water medium relief valve is designed to satisfy fast loading demand...

  10. Effect of forming rate on the impact tensile properties of the steels under crash test

    OpenAIRE

    Grumbach, M; Bayraktar, E.; Kaplan, D.(Department of Physics, Illinois Institute of Technology, Chicago, Illinois, 60616, U.S.A.)

    2007-01-01

    Purpose: The main objective of this study is to examine the mechanical and metallurgical behaviour of thetailored blanks and base metals for thin sheet steels used in the car industry by using a new type of crash test/impact (ITT). It exposes the effect of forming rate on the toughness of thin welded joints (tailored blanks) forInterstitial Free (IFS) steels used in the automotive industry.Design/methodology/approach: A special crash test device is used in different temperature and the simula...

  11. Normalizing and scaling of data to derive human response corridors from impact tests.

    Science.gov (United States)

    Yoganandan, Narayan; Arun, Mike W J; Pintar, Frank A

    2014-06-01

    It is well known that variability is inherent in any biological experiment. Human cadavers (Post-Mortem Human Subjects, PMHS) are routinely used to determine responses to impact loading for crashworthiness applications including civilian (motor vehicle) and military environments. It is important to transform measured variables from PMHS tests (accelerations, forces and deflections) to a standard or reference population, termed normalization. The transformation process should account for inter-specimen variations with some underlying assumptions used during normalization. Scaling is a process by which normalized responses are converted from one standard to another (example, mid-size adult male to large-male and small-size female adults, and to pediatric populations). These responses are used to derive corridors to assess the biofidelity of anthropomorphic test devices (crash dummies) used to predict injury in impact environments and design injury mitigating devices. This survey examines the pros and cons of different approaches for obtaining normalized and scaled responses and corridors used in biomechanical studies for over four decades. Specifically, the equal-stress equal-velocity and impulse-momentum methods along with their variations are discussed in this review. Methods ranging from subjective to quasi-static loading to different approaches are discussed for deriving temporal mean and plus minus one standard deviation human corridors of time-varying fundamental responses and cross variables (e.g., force-deflection). The survey offers some insights into the potential efficacy of these approaches with examples from recent impact tests and concludes with recommendations for future studies. The importance of considering various parameters during the experimental design of human impact tests is stressed. PMID:24726322

  12. The Impact of Cognitive Testing on the Welfare of Group Housed Primates

    OpenAIRE

    Whitehouse, Jamie; Micheletta, Jerome; Powell, Lauren E.; Bordier, Celia; Waller, Bridget M.

    2013-01-01

    Providing cognitive challenges to zoo-housed animals may provide enriching effects and subsequently enhance their welfare. Primates may benefit most from such challenges as they often face complex problems in their natural environment and can be observed to seek problem solving opportunities in captivity. However, the extent to which welfare benefits can be achieved through programmes developed primarily for cognitive research is unknown. We tested the impact of voluntary participation cognit...

  13. Further testing the impact of shift schedule on task scale variables for medical laboratory professionals.

    Science.gov (United States)

    Blau, Gary; Fertig, Jason; Lopez, Andrea; Aaronson, William; Holladay, Blair

    2007-01-01

    Using a broader sample of medical laboratory professionals, this study extended prior work by Blau and Lunz testing the impact of shift schedule on task scales. Overall the results supported the study hypothesis-i.e., medical laboratory professionals on a fixed day shift have lower job content routinization (higher task enrichment) than fixed evening and night and rotating shifts. Future research issues and study limitations are briefly discussed. PMID:18293804

  14. Review of Evidence of Environmental Impacts of Animal Research and Testing

    OpenAIRE

    Katherine Groff; Eric Bachli; Molly Lansdowne; Theodora Capaldo

    2014-01-01

    Millions of animals are used in research and toxicity testing, including in drug, medical device, chemical, cosmetic, personal care, household, and other product sectors, but the environmental consequences are yet to be adequately addressed. Evidence suggests that their use and disposal, and the associated use of chemicals and supplies, contribute to pollution as well as adverse impacts on biodiversity and public health. The objective of this review is to examine such evidence. The review in...

  15. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives

    Science.gov (United States)

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives. PMID:26983080

  16. THRESHOLD STUDIES ON TNT, COMPOSITION B, C-4, AND ANFO EXPLOSIVES USING THE STEVEN IMPACT TEST

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, K S; Switzer, L L; Garcia, F

    2006-06-20

    Steven Impact Tests were performed at low velocity on the explosives TNT (trinitrotolulene), Composition B (63% RDX, 36% TNT, and 1% wax by weight), C-4 (91% RDX, 5.3% Di (2-ethylhexyl) sebacate, 2.1% Polyisobutylene, and 1.6% motor oil by weight) and ANFO (94% ammonium Nitrate with 6% Fuel Oil) in attempts to obtain a threshold for reaction. A 76 mm helium driven gas gun was used to accelerate the Steven Test projectiles up to approximately 200 m/s in attempts to react (ignite) the explosive samples. Blast overpressure gauges, acoustic microphones, standard video and high-speed photography were used to characterize the level of any high explosive reaction violence. No bulk reactions were observed in the TNT, Composition B, C-4 or ANFO explosive samples impacted up to velocities in the range of 190-200 m/s. This work will outline the experimental details and discuss the lack of reaction when compared to the reaction thresholds of other common explosives. These results will also be compared to that of the Susan Test and reaction thresholds observed in the common small-scale safety tests such as the drop hammer and friction tests in hopes of drawing a correlation.

  17. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives.

    Science.gov (United States)

    Kozowyk, P R B; Langejans, G H J; Poulis, J A

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives. PMID:26983080

  18. Compaction comparison testing using a modified impact soil tester and nuclear density gauge

    International Nuclear Information System (INIS)

    The purpose of this paper is to compare test results of a modified Impact Soil Tester (IST) on compacted soil with data obtained from the same soil using a nuclear density gauge at the US Army Corp of Engineer's Buena Vista Flood Wall project in Buena Vista, Virginia. The tests were run during construction of the earth flood wall during the summer of 1996. This comparison testing demonstrated the credibility of the procedure developed for the IST as a compacting testing device. The comparison data was obtained on a variety of soils ranging from silty sands to clays. The Flood Wall comparison compaction data for 90% Standard Proctor shows that the results of the IST as modified are consistent with the nuclear density gauge 89% of the time for all types of soil tested. However, if the soils are more cohesive than the results are consistent with the nuclear density gauge 97% of the time. In addition these comparison tests are in general agreement with comparison compaction testing using the same testing techniques and methods of compacted backfill in utility trenches conducted earlier for the Public Works Department, Chesterfield County, Virginia

  19. An investigation on impacts of scheduling configurations on Mississippi biology subject area testing

    Science.gov (United States)

    Marchette, Frances Lenora

    The purpose of this mixed modal study was to compare the results of Biology Subject Area mean scores of students on a 4 x 4 block schedule, A/B block schedule, and traditional year-long schedule for 1A to 5A size schools. This study also reviewed the data to determine if minority or gender issues might influence the test results. Interviews with administrators and teachers were conducted about the type of schedule configuration they use and the influence that the schedule has on student academic performance on the Biology Subject Area Test. Additionally, this research further explored whether schedule configurations allow sufficient time for students to construct knowledge. This study is important to schools, teachers, and administrators because it can assist them in considering the impacts that different types of class schedules have on student performance and if ethnic or gender issues are influencing testing results. This study used the causal-comparative method for the quantitative portion of the study and constant comparative method for the qualitative portion to explore the relationship of school schedules on student academic achievement on the Mississippi Biology Subject Area Test. The aggregate means of selected student scores indicate that the Mississippi Biology Subject Area Test as a measure of student performance reveals no significant difference on student achievement for the three school schedule configurations. The data were adjusted for initial differences of gender, minority, and school size on the three schedule configurations. The results suggest that schools may employ various schedule configurations and expect student performance on the Mississippi Biology Subject Area Test to be unaffected. However, many areas of concern were identified in the interviews that might impact on school learning environments. These concerns relate to effective classroom management, the active involvement of students in learning, the adequacy of teacher education

  20. Explaining the black-white gap in cognitive test scores: Toward a theory of adverse impact.

    Science.gov (United States)

    Cottrell, Jonathan M; Newman, Daniel A; Roisman, Glenn I

    2015-11-01

    In understanding the causes of adverse impact, a key parameter is the Black-White difference in cognitive test scores. To advance theory on why Black-White cognitive ability/knowledge test score gaps exist, and on how these gaps develop over time, the current article proposes an inductive explanatory model derived from past empirical findings. According to this theoretical model, Black-White group mean differences in cognitive test scores arise from the following racially disparate conditions: family income, maternal education, maternal verbal ability/knowledge, learning materials in the home, parenting factors (maternal sensitivity, maternal warmth and acceptance, and safe physical environment), child birth order, and child birth weight. Results from a 5-wave longitudinal growth model estimated on children in the NICHD Study of Early Child Care and Youth Development from ages 4 through 15 years show significant Black-White cognitive test score gaps throughout early development that did not grow significantly over time (i.e., significant intercept differences, but not slope differences). Importantly, the racially disparate conditions listed above can account for the relation between race and cognitive test scores. We propose a parsimonious 3-Step Model that explains how cognitive test score gaps arise, in which race relates to maternal disadvantage, which in turn relates to parenting factors, which in turn relate to cognitive test scores. This model and results offer to fill a need for theory on the etiology of the Black-White ethnic group gap in cognitive test scores, and attempt to address a missing link in the theory of adverse impact. PMID:25867168

  1. Quantitative impact characterization of aeronautical CFRP materials with non-destructive testing methods

    Energy Technology Data Exchange (ETDEWEB)

    Kiefel, Denis, E-mail: Denis.Kiefel@airbus.com, E-mail: Rainer.Stoessel@airbus.com; Stoessel, Rainer, E-mail: Denis.Kiefel@airbus.com, E-mail: Rainer.Stoessel@airbus.com [Airbus Group Innovations, Munich (Germany); Grosse, Christian, E-mail: Grosse@tum.de [Technical University Munich (Germany)

    2015-03-31

    In recent years, an increasing number of safety-relevant structures are designed and manufactured from carbon fiber reinforced polymers (CFRP) in order to reduce weight of airplanes by taking the advantage of their specific strength into account. Non-destructive testing (NDT) methods for quantitative defect analysis of damages are liquid- or air-coupled ultrasonic testing (UT), phased array ultrasonic techniques, and active thermography (IR). The advantage of these testing methods is the applicability on large areas. However, their quantitative information is often limited on impact localization and size. In addition to these techniques, Airbus Group Innovations operates a micro x-ray computed tomography (μ-XCT) system, which was developed for CFRP characterization. It is an open system which allows different kinds of acquisition, reconstruction, and data evaluation. One main advantage of this μ-XCT system is its high resolution with 3-dimensional analysis and visualization opportunities, which enables to gain important quantitative information for composite part design and stress analysis. Within this study, different NDT methods will be compared at CFRP samples with specified artificial impact damages. The results can be used to select the most suitable NDT-method for specific application cases. Furthermore, novel evaluation and visualization methods for impact analyzes are developed and will be presented.

  2. Simulation of an impact test with a deformable missile on a concrete wall

    International Nuclear Information System (INIS)

    In the framework of the reactor safety research program of the German Federal Ministry of Economics and Technology GRS has started to validate the structure mechanics analysis method based on the nonlinear dynamic software ANSYS AUTODYN with respect to its capability to simulate the impact of deformable missiles on resistant barriers. For the validation of analysis models to determine the mechanical load assumptions and the consequences, small scale tests on the fragmentation of fragile projectiles when impacting on solid targets are performed at different test facilities. The paper summarizes a study using ANSYS AUTODYN simulations of an impact test with a thin-walled aluminum missile on a reinforced concrete wall performed at the Technical Research Centre of Finland VTT. The comparison of numerical results with measured data shows satisfactory results especially concerning the deformation of the concrete wall and the fragmentation of the missile. Relevant influence parameters on the results are the boundary conditions, the mesh size, strain rate sensitive material properties and the damping which have to be chosen adequately

  3. Quantitative impact characterization of aeronautical CFRP materials with non-destructive testing methods

    Science.gov (United States)

    Kiefel, Denis; Stoessel, Rainer; Grosse, Christian

    2015-03-01

    In recent years, an increasing number of safety-relevant structures are designed and manufactured from carbon fiber reinforced polymers (CFRP) in order to reduce weight of airplanes by taking the advantage of their specific strength into account. Non-destructive testing (NDT) methods for quantitative defect analysis of damages are liquid- or air-coupled ultrasonic testing (UT), phased array ultrasonic techniques, and active thermography (IR). The advantage of these testing methods is the applicability on large areas. However, their quantitative information is often limited on impact localization and size. In addition to these techniques, Airbus Group Innovations operates a micro x-ray computed tomography (μ-XCT) system, which was developed for CFRP characterization. It is an open system which allows different kinds of acquisition, reconstruction, and data evaluation. One main advantage of this μ-XCT system is its high resolution with 3-dimensional analysis and visualization opportunities, which enables to gain important quantitative information for composite part design and stress analysis. Within this study, different NDT methods will be compared at CFRP samples with specified artificial impact damages. The results can be used to select the most suitable NDT-method for specific application cases. Furthermore, novel evaluation and visualization methods for impact analyzes are developed and will be presented.

  4. The overall impact of testing on medical student learning: quantitative estimation of consequential validity.

    Science.gov (United States)

    Kreiter, Clarence D; Green, Joseph; Lenoch, Susan; Saiki, Takuya

    2013-10-01

    Given medical education's longstanding emphasis on assessment, it seems prudent to evaluate whether our current research and development focus on testing makes sense. Since any intervention within medical education must ultimately be evaluated based upon its impact on student learning, this report seeks to provide a quantitative accounting of the learning gains attained through educational assessments. To approach this question, we estimate achieved learning within a medical school environment that optimally utilizes educational assessments. We compare this estimate to learning that might be expected in a medical school that employs no educational assessments. Effect sizes are used to estimate testing's total impact on learning by summarizing three effects; the direct effect, the indirect effect, and the selection effect. The literature is far from complete, but the available evidence strongly suggests that each of these effects is large and the net cumulative impact on learning in medical education is over two standard deviations. While additional evidence is required, the current literature shows that testing within medical education makes a strong positive contribution to learning. PMID:22886140

  5. Quantitative impact characterization of aeronautical CFRP materials with non-destructive testing methods

    International Nuclear Information System (INIS)

    In recent years, an increasing number of safety-relevant structures are designed and manufactured from carbon fiber reinforced polymers (CFRP) in order to reduce weight of airplanes by taking the advantage of their specific strength into account. Non-destructive testing (NDT) methods for quantitative defect analysis of damages are liquid- or air-coupled ultrasonic testing (UT), phased array ultrasonic techniques, and active thermography (IR). The advantage of these testing methods is the applicability on large areas. However, their quantitative information is often limited on impact localization and size. In addition to these techniques, Airbus Group Innovations operates a micro x-ray computed tomography (μ-XCT) system, which was developed for CFRP characterization. It is an open system which allows different kinds of acquisition, reconstruction, and data evaluation. One main advantage of this μ-XCT system is its high resolution with 3-dimensional analysis and visualization opportunities, which enables to gain important quantitative information for composite part design and stress analysis. Within this study, different NDT methods will be compared at CFRP samples with specified artificial impact damages. The results can be used to select the most suitable NDT-method for specific application cases. Furthermore, novel evaluation and visualization methods for impact analyzes are developed and will be presented

  6. Uniform Foam Crush Testing for Multi-Mission Earth Entry Vehicle Impact Attenuation

    Science.gov (United States)

    Patterson, Byron W.; Glaab, Louis J.

    2012-01-01

    Multi-Mission Earth Entry Vehicles (MMEEVs) are blunt-body vehicles designed with the purpose of transporting payloads from outer space to the surface of the Earth. To achieve high-reliability and minimum weight, MMEEVs avoid use of limited-reliability systems, such as parachutes and retro-rockets, instead using built-in impact attenuators to absorb energy remaining at impact to meet landing loads requirements. The Multi-Mission Systems Analysis for Planetary Entry (M-SAPE) parametric design tool is used to facilitate the design of MMEEVs and develop the trade space. Testing was conducted to characterize the material properties of several candidate impact foam attenuators to enhance M-SAPE analysis. In the current effort, four different Rohacell foams are tested at three different, uniform, strain rates (approximately 0.17, approximately 100, approximately 13,600%/s). The primary data analysis method uses a global data smoothing technique in the frequency domain to remove noise and system natural frequencies. The results from the data indicate that the filter and smoothing technique are successful in identifying the foam crush event and removing aberrations. The effect of strain rate increases with increasing foam density. The 71-WF-HT foam may support Mars Sample Return requirements. Several recommendations to improve the drop tower test technique are identified.

  7. Quantifying the impact of future Sandage-Loeb test data on dark energy constraints

    International Nuclear Information System (INIS)

    The Sandage-Loeb (SL) test is a unique method to probe dark energy in the ''redshift desert'' of 2∼test data impact on the dark energy constraints. To avoid the potential inconsistency in data, we use the best-fitting model based on the other geometric measurements as the fiducial model to produce 30 mock SL test data. The 10-yr, 20-yr, and 30-yr observations of SL test are analyzed and compared in detail. We show that compared to the current combined data of type Ia supernovae, baryon acoustic oscillation, cosmic microwave background, and Hubble constant, the 30-yr observation of SL test could improve the constraint on Ωm by about 80% and the constraint on w by about 25%. Furthermore, the SL test can also improve the measurement of the possible direct interaction between dark energy and dark matter. We show that the SL test 30-yr data could improve the constraint on γ by about 30% and 10% for the Q = γHρc and Q = γHρde models, respectively

  8. INFLUENCE OF COOLING RATE DURING QUENCHING ON IMPACT TOUGHNESS OF A HOT-WORK TOOL STEEL AT AMBIENT TEMPERATURE AND AT 200 °C

    Directory of Open Access Journals (Sweden)

    Henrik Jesperson

    2013-05-01

    Full Text Available Gross cracking of die-casting dies with inferior toughness sometimes occurs through too low preheating temperature and/or too slow cooling during quenching. This study aimed to clarify the influence of cooling rate on the toughness of the hot-work tool steel grade Uddeholm Vidar Superior at ambient temperature and at 200 °C, a typical preheating temperature for aluminium die-casting dies. Toughness was measured through instrumented Charpy V-notch impact testing. The decrease in energy absorption with increasing cooling time between 800°C and 500°C both at both ambient temperature and 200 °C was pronounced. At ambient temperature, the decrease in total energy was a consequence of a decrease in initiation energy whereas, at 200 °C, the decrease in total energy was due to a decrease in propagation energy.

  9. Evaluating cover depth of steel fiber reinforced concrete using impact-echo testing

    Science.gov (United States)

    Lin, Yu-Feng

    2014-04-01

    The purpose of this research is to estimate of the cover depth of steel fiber reinforced concrete using the impact-echo testing. In order to evaluate the security of the construction, usually need to estimate the cover depth of the reinforced concrete. At present, the examination technique of the cover depth of the reinforced concrete without the steel fiber is mainly applied in the magnetic and electrical methods, its rapid detection and good results. But the research of the reactive powder concrete be gradually progress, with the steel fiber concrete structure will be increased, if should still operate the examination with the magnetic and electrical methods, theoretically the steel fiber will have the interference to its electromagnetism field. Therefore, this research designs four kinds of reinforced concrete plate that include different steel fiber contents, to evaluate test results of estimate of the cover depth of the reinforcing bar. The results showed that: estimate of the cover depth of steel fiber reinforced concrete reinforcing bar using the impact-echo testing, the variety of the steel fiber content does not have much influence, the test measurement error within ± 10%, and the most important source of uncertainty is the velocity of concrete.

  10. A theoretical model for determination of fracture toughness of reactor pressure vessel steels in the transition region from automated ball indentation test

    International Nuclear Information System (INIS)

    A theoretical model is proposed to estimate the fracture toughness of ferritic steels in the transition region from ball indentation test data. The key concept of the model is that the indentation energy to a critical load is related to the fracture energy of the material. By applying the new model, the fracture parameters of reactor pressure vessel steel base and weld metals were estimated from the indentation load-depth curves. The estimated fracture stresses agreed well with those of the Wilshaw et al. model. The temperature dependence of the estimated KJC was almost the same as that of the ASTM KJC master curve. Also, the reference temperature obtained from the estimated KJC versus temperature curve correlated well with the index temperature of 41 J Charpy impact energy, T41J. Additionally, the ball indentation deformation was simulated by ABAQUS code to evaluate the stress state and the result was compared with that at the crack tip. (orig.)

  11. The impact of screening-test negative samples not enumerated by MPN

    DEFF Research Database (Denmark)

    Corbellini, Luis Gustavo; Ribeiro Duarte, Ana Sofia; de Knegt, Leonardo; Silva, Luis Eduardo da; Cardoso, Marisa; Nauta, Maarten

    2015-01-01

    In microbiological surveys, false negative results in detection tests precluding the enumeration by MPN may occur. The objective of this study was to illustrate the impact of screening test failure on the probability distribution of Salmonella concentrations in pork using a Bayesian method. A total...... of 276 swab samples in four slaughter steps (69 samples in each slaughter step: after dehairing, after singeing, after evisceration, and before chilling) were screened for Salmonella and enumerated by the MPN method. Salmonella contamination data were fitted to a lognormal distribution by using a...... Bayesian model that uses the number of positive tubes at each dilution in an MPN analysis to estimate the parameters of the concentration distribution. With Salmonella paired data, three data sets were used for each slaughter step: one that includes the positives in the screening test only, a second one...

  12. Impact of criticism of null-hypothesis significance testing on statistical reporting practices in conservation biology.

    Science.gov (United States)

    Fidler, Fiona; Burgman, Mark A; Cumming, Geoff; Buttrose, Robert; Thomason, Neil

    2006-10-01

    Over the last decade, criticisms of null-hypothesis significance testing have grown dramatically, and several alternative practices, such as confidence intervals, information theoretic, and Bayesian methods, have been advocated. Have these calls for change had an impact on the statistical reporting practices in conservation biology? In 2000 and 2001, 92% of sampled articles in Conservation Biology and Biological Conservation reported results of null-hypothesis tests. In 2005 this figure dropped to 78%. There were corresponding increases in the use of confidence intervals, information theoretic, and Bayesian techniques. Of those articles reporting null-hypothesis testing--which still easily constitute the majority--very few report statistical power (8%) and many misinterpret statistical nonsignificance as evidence for no effect (63%). Overall, results of our survey show some improvements in statistical practice, but further efforts are clearly required to move the discipline toward improved practices. PMID:17002771

  13. Investigations on the impact strength of constructional high-strength Weldox steel at lowered temperature

    Directory of Open Access Journals (Sweden)

    W. Ozgowicz

    2008-08-01

    Full Text Available Purpose: The paper presents the results of investigations concerning the impact strength of thick steel plates at lowered temperature obtained by industrial smelting of micro-alloyed steel of the type S1100QL (Weldox 1100 and S1300QL (Weldox 1300 with a yield strength of 1100-1300 MPa.Design/methodology/approach: The main methods used for these researches were the impact test Charpy V at lower temperatures, and metallographic observations. The tested samples at lower temperature have also been analyzed fractographically.Findings: The influence of the chemical composition and technology of production on the structure and mechanical properties of the investigated kinds of steels have been determined, as well as their ductility temperature of transition into the brittle state.Research limitations/implications: A large dispersion of intermetallic precipitated phases restricted considerably the possibility of their metallographic identification. This latter one will be done in the next stage of basic investigations.Practical implications: A wide range of practical applications of Weldox 1100 and Weldox 1300 sheet plates is warranted by both their high impact strength, especially at lower temperatures, and lower ductility transition temperature.Originality/value: It has been found that the degree of refinement of the martensitic structure and dispersion of secondary precipitations, mainly carbides and niobium nitrocarbides affect considerably the change of the impact strength within the investigated range of temperature from ambient temperature to minus 150°C.

  14. Hypervelocity impact testing of advanced materials and structures for micrometeoroid and orbital debris shielding

    Science.gov (United States)

    Ryan, Shannon; Christiansen, Eric L.

    2013-02-01

    A series of 66 hypervelocity impact experiments have been performed to assess the potential of various materials (aluminium, titanium, copper, stainless steel, nickel, nickel/chromium, reticulated vitreous carbon, silver, ceramic, aramid, ceramic glass, and carbon fibre) and structures (monolithic plates, open-cell foam, flexible fabrics, rigid meshes) for micrometeoroid and orbital debris (MMOD) shielding. Arranged in various single-, double-, and triple-bumper configurations, screening tests were performed with 0.3175 cm diameter Al2017-T4 spherical projectiles at nominally 6.8 km/s and normal incidence. The top performing shields were identified through target damage assessments and their respective weight. The top performing candidate shield at the screening test condition was found to be a double-bumper configuration with a 0.25 mm thick Al3003 outer bumper, 6.35 mm thick 40 PPI aluminium foam inner bumper, and 1.016 mm thick Al2024-T3 rear wall (equal spacing between bumpers and rear wall). In general, double-bumper candidates with aluminium plate outer bumpers and foam inner bumpers were consistently found to be amongst the top performers. For this impact condition, potential weight savings of at least 47% over conventional all-aluminium Whipple shields are possible by utilizing the investigated materials and structures. The results of this study identify materials and structures of interest for further, more in-depth, impact investigations.

  15. Laminated Windshield Breakage Modelling in the Context of Headform Impact Homologation Tests

    Science.gov (United States)

    Kosiński, P.; Osiński, J.

    2015-02-01

    The purpose of modelling a laminated windshield using the FEM is to provide a critical look on the way the adult headform impact tests are conducted in the process of motor vehicle certification. The main aim of the study is to modify the design of a laminated windshield in the context of a vehicle collision with vulnerable road users. The initial phase of the work was to develop a model of the adult headform impactor. The validation consisted in conducting a series of FEM analyses of the impactor certification testing according to the Regulation (EC) 631/2009. Next, the impact of the headform model on a windshield was analysed. The FEM model of laminated glass is composed of two outer layers of glass and an inner layer of polyvinyl butyral. FEM analyses of the impaction were performed at five points of the windshield characterised by various dynamic responses of the impactor and various patterns of glass cracking. In modelling the layers of glass, the Abaqus environment "brittle cracking" model was used. The following material models of PVB resin were considered: elastic, elastic-plastic, hyperelastic, and low-density foam. Furthermore, the influence of the mesh type on the process of glass cracking in a laminated windshield was analysed.

  16. Threshold Studies of Heated HMX-Based Energetic Material Targets Using the Steven Impact Test

    Energy Technology Data Exchange (ETDEWEB)

    Switzer, L L; Vandersall, K S; Chidester, S K; Greenwood, D W; Tarver, C M

    2003-07-01

    Impact tests performed at low velocity on heated energetic material samples are of interest when considering the situation of energetic materials involved in a fire. To determine heated reaction thresholds, Steven Test targets containing PBX 9404 or LX-04 samples heated to the range of 150-170 C were impacted at velocities up to 150 m/s by two different projectile head geometries. Comparing these measured thresholds to ambient temperature thresholds revealed that the heated LX-04 thresholds were considerably higher than ambient, whereas the heated PBX 9404 thresholds were only slightly higher than the ambient temperature thresholds. The violence of reaction level of the PBX 9404 was considerably higher than that of the LX-04 as measured with four overpressure gauges. The varying results in these samples with different HMX/binder configurations indicate that friction plays a dominant role in reaction ignition during impact. This work outlines the experimental details, compares the thresholds and violence levels of the heated and ambient temperature experiments, and discusses the dominant mechanisms of the measured thresholds.

  17. Acoustic Emission Monitoring of Lightning-Damaged CFRP Laminates during Compression-after-Impact Test

    International Nuclear Information System (INIS)

    Carbon-fiber reinforced plastic(CFRP) laminates made of nano-particle-coated carbon fibers and damaged by a simulated lightning strike were tested under compression-after-impact(CAI) mode, during which the damage progress due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. Conductive nano-particles were coated directly on the fibers, from which CFRP coupons were made. The coupon were subjected to the strikes with a high voltage/current impulse of 10-40 kA within a few . The effects of nano-particle coating and the degree of damage induced by the simulated lightning strikes on AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terms of damage area by using ultrasonic C-scan images. The assessment during the CAI tests of damaged CFRP showed that AE monitoring appeared to be useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes.

  18. Full scale test results for ship ice impact forces and pressures

    International Nuclear Information System (INIS)

    A set of full scale impact tests were carried out for the icebreakers Canmar Kigoriak and Robert LeMeur in first and multi-year ice conditions in the southern Beaufort Sea. Preliminary results of the testing program were published in Ghoneim et al. (1984). This paper presents some salient results of further analysis of the data. This includes a description of the different types of ice ramming mechanisms and the corresponding ice force time histories and ship response. A comparison between the bow force peak values for the kigoriak and the Robert LeMeur is made and the reasons for the difference are evaluated. The question of dynamic magnification of the response is investigated. The relationship between the peak impact force and the ramming velocity is evaluated for both ships and compared with theoretical and empirical formulations. Other parametric relationships are presented, including such parameters as force duration and relative magnitude of the impact and beaching bow forces. The added mass is evaluated from measured accelerations and calculated bow forces and are shown to be time dependent. The relationship between ice pressure and corresponding contact area is discussed. Finally, conclusions and recommendations are presented

  19. Impact property at cryogenic temperature of candidate materials for fusion reactor and their electron beam welded joint

    International Nuclear Information System (INIS)

    Impact properties at cryogenic temperature of candidate materials for fusion reactor and their electron beam welded joints are investigated by using instrumented Charpy impact testing apparatus. Material used are aluminum alloys (A7N01, A5083, A6061), JFMS (Japanese Ferritic Martensitic Steel) and two kinds of high manganese steels. Although JFMS is a steel for high temperature use, the impact test is conducted at low temperature same as the cases of the other materials. Testing results are obtained as follows. 1. Base metals and welded joint of aluminum alloys exhibit high absorbed energy at low temperature. Ductility of each base metal and welded joint gradually decreases with decreasing of testing temperature. 2. Base metal and welded joint of JFMS exhibit an absorbed energy transition temperature at near a room temperature. 3. Base metal and welded joint of high manganese steel A-T (18Mn) exhibit abrupt decreasing of absorbed energy at 77K, but base metal and welded joint of high manganese steel B-T (22Mn-0.2N) exhibit gradual increasing of maximum strength and decreasing of ductility with decreasing of testing temperature. (author)

  20. Ubiquitous testing using tablets: its impact on medical student perceptions of and engagement in learning

    Science.gov (United States)

    Kim, Kyong-Jee; Hwang, Jee-Young

    2016-01-01

    Purpose: Ubiquitous testing has the potential to affect medical education by enhancing the authenticity of the assessment using multimedia items. This study explored medical students’ experience with ubiquitous testing and its impact on student learning. Methods: A cohort (n=48) of third-year students at a medical school in South Korea participated in this study. The students were divided into two groups and were given different versions of 10 content-matched items: one in text version (the text group) and the other in multimedia version (the multimedia group). Multimedia items were delivered using tablets. Item response analyses were performed to compare item characteristics between the two versions. Additionally, focus group interviews were held to investigate the students’ experiences of ubiquitous testing. Results: The mean test score was significantly higher in the text group. Item difficulty and discrimination did not differ between text and multimedia items. The participants generally showed positive responses on ubiquitous testing. Still, they felt that the lectures that they had taken in preclinical years did not prepare them enough for this type of assessment and clinical encounters during clerkships were more helpful. To be better prepared, the participants felt that they needed to engage more actively in learning in clinical clerkships and have more access to multimedia learning resources. Conclusion: Ubiquitous testing can positively affect student learning by reinforcing the importance of being able to understand and apply knowledge in clinical contexts, which drives students to engage more actively in learning in clinical settings. PMID:26838569

  1. Tests to evaluate the ecological impact of treated ballast water on three Chinese marine species

    Science.gov (United States)

    Zhang, Yanan; Wang, Zixi; Cai, Leiming; Cai, Xiang; Sun, Wenjun; Ma, Liqing

    2014-09-01

    Ballast water has been a topic of concern for some time because of its potential to introduce invasive species to new habitats. To comply with the International Convention for the Control and Management of Ships' Ballast Water and Sediments, members of the International Maritime Organization (IMO) must equip their ships with on-board treatment systems to eliminate organism release with ballast water. There are many challenges associated with the implementation of this IMO guideline, one of which is the selection of species for testing the ecological impacts of the treated ballast water. In the United States, ballast water toxicity test methods have been defined by the United States Environmental Protection Agency. However, the test methods had not been finalized in China until the toxicity test methods for ballast water were established in 2008. The Chinese methods have been based on species from three trophic levels: Skeletonema costatum, Neomysis awatschensis, and Ctenogobius gymnauchen. All three species live in broad estuarine and open sea areas of China; they are sensitive to reference toxicants and acclimatize easily to different conditions. In this paper, the biological characteristics, test processes and statistical analysis methods are presented for the three species. Results indicate that the methods for evaluating these three organisms can be included in the ecological toxicity tests for treated ballast water in China.

  2. 46 CFR 54.05-10 - Certification of material toughness tests.

    Science.gov (United States)

    2010-10-01

    ... Section 54.05-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING... rolling. (b) Pipe or tube material. (1) The manufacturer of pipe, tube, or welded fittings formed from pipe or tube may certify such material by reporting the results of tests of one set of Charpy...

  3. On the validity of Ksub(Id)-measurements in instrumented impact tests

    International Nuclear Information System (INIS)

    The influence of inertia effects in determining the dynamic fracture toughness Ksub(Id) by instrumented impact testing is investigated. Model experiments in the brittle fracture regime are carried out with precracked bend specimens machined from the epoxy resin Araldite B. As is usual in these tests, the loads at the tup of the impinging striker are recorded as a function of time during the impact process. For reference purposes, the dynamic fracture toughness value Ksub(Id)sup(m1) is derived from the measured maximum load utilizing static stress intensity factor formulas. In addition to this conventional procedure, the actual stress intensity factors are measured directly at the tip of the crack by means of the shadow optical method of caustics applied in combination with high speed photography. The critical value of these optically measured stress intensity factors (for onset of crack propagation), Ksub(Id)sup(opt), is the true dynamic fracture toughness. In the experiments, the specimen size and the impact velocity were varied. In accordance with expectations, it is found that the hammer load signal is not correlated with the actual crack tip stress intensity factor values by a simple proportionality. The conventionally determined Ksub(Id)sup(m1)-value overestimates the true dynamic fracture toughness Ksub(Id)sup(opt). This overestimation becomes larger for larger specimen sizes and larger impact velocities. The results demonstrate the dominating influence inertia effects can have on hammer load measurements and emphasize the importance of eliminating these effects in order to determine non-erroneous dynamic fracture toughness values. (orig.)

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

    International Nuclear Information System (INIS)

    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: CVNpc and RCT type specimens are suitable for determining the materials fracture toughness even in the ductile/brittle transition region provided the elastic-plastic parameter KJC 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

  5. Toughness characterization by small specimen test technique for HIPed joints of F82H steel aiming at first wall fabrication in fusion

    Science.gov (United States)

    Kishimoto, H.; Ono, T.; Sakasegawa, H.; Tanigawa, H.; Kohno, Y.; Kohyama, A.

    2013-09-01

    Reduced activation ferritic/martensitic steels (RAFMs), such as F82H steels, have been developed as candidates of structural materials for fusion. In the design of a fusion reactor, cooling channels are built in the first wall of the blanket. One large issue is to determine how to join rectangular tubes to thin panels to fabricate the first wall. Hot Isostatic Pressing (HIPing) is a solution to solve the issue. Because of the thin HIPed walls of the channels, the specimen size for inspection of HIPed interface is limited. In the present research, Small Specimen Test Techniques (SSTT) are screened for the destructive toughness investigation technique of HIPed F82H joints. 1/3 size Charpy V-notch impact (1/3 CVN) and small punch (SP) tests are employed for the present research. The toughness of the HIPed joints is strongly affected by various surface finishing of specimens treated previous to the HIPing. In the present research, several kinds of HIPed joints were surface finished by different methods and investigated by 1/3 CVN impact test. The HIPed F82H joints had different toughness ranging from 20% to 70% of the toughness of the F82H base metal. The SP test is also available for the investigation of toughness change by the HIPing. The sensitivity of 1/3 CVN impact test against toughness change was better than the SP test, it revealed that the SP test has some limitations.

  6. Testing the impact on natural risks' awareness of visual communication through an exhibition

    Science.gov (United States)

    Charrière, Marie; Bogaard, Thom; Junier, Sandra; Malet, Jean-Philippe; Mostert, Erik

    2014-05-01

    The need to communicate about natural disasters in order to improve the awareness of communities at risk is not a matter for debate anymore. However, communication can be implemented using different media and tools, and their effectiveness may be difficult to grasp. Current research on the topic is usually focused on assessing whether communication practices meet users' needs, whereas impact assessment is mostly left out. It can be explained by difficulties arising from (1) the definition of the impact to measure, i.e. awareness, and the appropriate indicators to measure it and its variations, and (2) the implementation of a research design that allows assessing these impacts without bias. This research aims at both developing a methodology to measure risk awareness and to use it for testing the effectiveness of visual communication. The testing was conducted in the Ubaye Valley in France, an alpine area affected by multiple hazards, from December 2013 to mid-February 2014. The setting consisted of an exhibition in the public library of the main town, Barcelonnette. The main natural hazards of the study case (i.e. landslides, avalanches, flooding, debris flows and earthquakes), as well as structural and non-structural measures were presented to the general public using local examples of hazards events and mitigation. Various visualization tools were used: videos, Google earth map, interactive timeline, objects, mock-ups, technical devices as well as posters with pictures, drawings and graphs. In order to assess the effects of the exhibition on risk awareness, several groups of children and adults were submitted to a research design, consisting of 1) a pre-test, 2) the visit of the exhibition and 3) a post-test similar to the pre-test. Close-ended questions addressed the awareness indicators according to the literature, i.e. worry level, previous experiences with natural hazards events, exposure to awareness raising, ability to mitigate/respond/prepare, attitude to

  7. Oblique Loading in Post Mortem Human Surrogates from Vehicle Lateral Impact Tests using Chestbands.

    Science.gov (United States)

    Yoganandan, Narayan; Humm, John R; Pintar, Frank A; Arun, Mike W J; Rhule, Heather; Rudd, Rodney; Craig, Matthew

    2015-11-01

    While numerous studies have been conducted to determine side impact responses of Post Mortem Human Surrogates (PMHS) using sled and other equipment, experiments using the biological surrogate in modern full-scale vehicles are not available. The present study investigated the presence of oblique loading in moving deformable barrier and pole tests. Threepoint belt restrained PMHS were positioned in the left front and left rear seats in the former and left front seat in the latter condition and tested according to consumer testing protocols. Three chestbands were used in each specimen (upper, middle and lower thorax). Accelerometers were secured to the skull, shoulder, upper, middle and lower thoracic vertebrae, sternum, and sacrum. Chestband signals were processed to determine magnitudes and angulations of peak deflections. The magnitude and timing of various signal peaks are given. Vehicle accelerations, door velocities, and seat belt loads are also given. Analysis of deformation contours, peak deflections, and angulations indicated that the left rear seated specimen were exposed to anterior oblique loading while left front specimens in both tests sustained essentially pure lateral loading to the torso. These data can be used to validate human body computational models. The occurrence of oblique loading in full-scale testing, hitherto unrecognized, may serve to stimulate the exploration of its role in injuries to the thorax and lower extremities in modern vehicles. It may be important to continue research in this area because injury metrics have a lower threshold for angled loading. PMID:26660738

  8. Assessing the Impact of Testing Aids on Post-Secondary Student Performance: A Meta-Analytic Investigation

    Science.gov (United States)

    Larwin, Karen H.; Gorman, Jennifer; Larwin, David A.

    2013-01-01

    Testing aids, including student-prepared testing aids (a.k.a., cheat sheets or crib notes) and open-textbook exams, are common practice in post-secondary assessment. There is a considerable amount of published research that discusses and investigates the impact of these testing aids. However, the findings of this research are contradictory and…

  9. Impact to non-destructive testing (NDT) companies of PNRI/PSNT trained NDT personnel

    International Nuclear Information System (INIS)

    This research discusses the impact to non-destructive testing (NDT) companies of PNRI/PSNT trained NDT personnel to the individual and to the organization that the individual belongs in the midst of competitive, demanding and fast-paced workplace in the NDT industry. Related literature and studies were carefully chosen and reviewed to validate the consistencies of the research design and data gathering relationship to the present undertaking to previous studies were also discussed and analyzed. The research design used were the descriptive-normative survey method together with a questionnaire consisting of six (6) parts. The first part includes queries on personal/demographic profiles of respondents. The second part contains queries on the level of expectation of the respondents of the job-related variables. The third part contains queries on the levels of adequacy of the organization-related variables. The fourth part consists of questions on the impact of the PNRI/PSNT trained NDT personnel before and after the training. It is divided into two sections, first was for the organization and second was for the individual development. The fifth part was on the analysis of the personal-related factors that influence the impact of the PNRI/PSNT trained NDT personnel. The last part was to find out the significant differences on the impact of the training as to methods. A five-point scale was used to quantify the degree of respondents' responses to queries in the questionnaires. In addition, the following statistical formula were used for treatment of gathered data were frequency percentage, ranking, wilcoxon signed ranks test and spearman rho. The null hypotheses that were presented for acceptance or rejection were also tested. Presentation of findings, analysis and interpretations were presented based on the data gathered and the computations. Recommendations were discussed based on the findings. It is recommended that training of NDT personnel in the different NDT

  10. Investigating the Impact of Convergent vs. Divergent Assessment on ESL Students’ Anxiety and Test Performance

    OpenAIRE

    Azar Saeedi Nasab; Esmaeil Bagheridoust; Kourosh Karimi

    2014-01-01

    Language assessment with its eye-catching nature, casts its spell on many researchers, spurring on them to study its telling role in different arenas. The present study with a closer look to the realm, keeps one eye on two fresh approaches in assessment, namely convergent and divergent, and the other one on anxiety in a bid to slash its negative impact on students’ performance. The researchers resort to a correlational method with Ex Post Facto design, along with different tests, to forward t...

  11. Modal Analysis of Small & Medium Structures by Fast Impact Hammer Testing (FIHT) Method

    OpenAIRE

    TIRELLI Daniel

    2011-01-01

    In the context of the SERIES project (Task 2.3: “software development for data processing”) concerning the availability of simple tools and techniques for real-time data analysis and interpretation, the present report discusses the use of the Fast Impact Hammer Testing method (FIHT) with the purpose of providing to the partners of SERIES the opportunity to use the FIHT method on the structures of the project, and at the same time to improve the method for the dynamic characterisation of stru...

  12. Gas Gun Impact Testing of PZT 95/5, Part 1: Unpoled State

    Energy Technology Data Exchange (ETDEWEB)

    FURNISH,MICHAEL D.; SETCHELL,ROBERT E.; CHHABILDAS,LALIT C.; MONTGOMERY,STEPHEN T.

    2000-01-01

    In the present study, 10 impact tests were conducted on unpoled PZT 95/5, with 9% porosity and 2 at% Nb doping. These tests were instrumented to obtain time-resolved loading, unloading and span signatures. As well, PVDF gauges allowed shock timing to be established explicitly. The ferroelectric/antiferroelectric phases transition was manifested as a ramp to 0.4 GPa. The onset of crushup produced the most visible signature: a clear wave separation at 2.2 GPa followed by a highly dispersive wave. The end states also reflected crushup, and are consistent with earlier data and with related poled experiments. A span strength value of 0.17 GPa was measured for a shock stress of 0.5 GPa, this decreased to a very small value (no visible pullback signature) for a shock strength of 1.85 GPa.

  13. Non-destructive testing of concrete structures with the impact-echo method

    International Nuclear Information System (INIS)

    The impact-echo method is based on the use of elastic waves. It was developed in the 1980 for the testing of concrete structures and is currently widespread. Main application areas are the component and coating thickness measurement and detection of delaminations, voids and other defects. Specifically, the method is also used to check the injection faults of clamping channels. Another application is the determination of mechanical material parameters such as the modulus of elasticity. Since the original development of the method has undergone several enhancements. The conversion of a single-point measurement method towards a area component testing, the use by the optimized measurement data acquisition and evaluation enlarged and delivered an important prerequisite for increasing the efficiency. The use of air-coupled sensors not only increases the measurement speed but also provides advantages in rough component surfaces. The imaging analysis in conjunction with signal processing algorithms simplifies the interpretation and allows statistical evaluation.

  14. Validating Material Modelling of OFHC Copper Using Dynamic Tensile Extrusion (DTE) Test at Different Impact Velocity

    Science.gov (United States)

    Bonora, Nicola; Testa, Gabriel; Ruggiero, Andrew; Iannitti, Gianluca; Hörnqvist, Magnus; Mortazavi, Nooshin

    2015-06-01

    In the Dynamic Tensile Extrusion (DTE) test, the material is subjected to very large strain, high strain rate and elevated temperature. Numerical simulation, validated comparing with measurements obtained on soft-recovered extruded fragments, can be used to probe material response under such extreme conditions and to assess constitutive models. In this work, the results of a parametric investigation on the simulation of DTE test of annealed OFHC copper - at impact velocity ranging from 350 up to 420 m/s - using phenomenological and physically based models (Johnson-Cook, Zerilli-Armstrong and Rusinek-Klepaczko), are presented. Preliminary simulation of microstructure evolution was performed using crystal plasticity package CPFEM, providing, as input, the strain history obtained with FEM at selected locations along the extruded fragments. Results were compared with EBSD investigation.

  15. The Impact of Time-Series Diagnostic Tests on the Writing Ability of Iranian EFL learners

    Directory of Open Access Journals (Sweden)

    Bahareh Molazem Atashgahi

    2014-02-01

    Full Text Available This study aimed to show whether administering a battery of time-series diagnostic tests (screening has any impact on Iranian EFL learners’ writing ability. The study was conducted on the intermediate EFL learners at Islamic Azad University North Tehran branch.  The researcher administered a homogenizing test in order to exclude the exceptional scores, among all the testers, only those whose scores were nearly within one standard deviation above or below the mean were selected as the participants of this study. After the assignment of the participants to the control and experimental groups- 30 students in each group- they were asked to write five-paragraph-essays on two topics. Such a pretest was given to both groups to test their initial writing ability. Once scoring of the students’ writings (five- paragraph essay was finished the two means of the groups were calculated and compared with each other through the t-test analysis. The result demonstrated that there was no statistically significant difference between those two groups regarding the variable under investigation. Four sets of diagnostic tests were given to the experimental group every two weeks and after each test both the result of the exam and suitable feedback regarding students’ errors were given to them by the teacher, while the Current-Traditional Rhetoric method was administered in the control group.In the posttest which was run after giving the treatment and placebo to experimental group and control group respectively, students took another writing test with the same characteristics in administration, topics and scoring as the one in pretest. Thereafter, the significance of the difference between the obtained means of experimental and control groups in the posttest was determined through the t-test.  The result of the t-test analysis indicated a significant difference between the two groups which consequently rejected the null hypothesis of the study.Therefore, any

  16. Seismic response prediction for cabinets of nuclear power plants by using impact hammer test

    International Nuclear Information System (INIS)

    An effective method to predict the seismic response of electrical cabinets of nuclear power plants is developed. This method consists of three steps: (1) identification of the earthquake-equivalent force based on the idealized lumped-mass system of the cabinet, (2) identification of the state-space equation (SSE) model of the system using input-output measurements from impact hammer tests, and (3) seismic response prediction by calculating the output of the identified SSE model under the identified earthquake-equivalent force. A three-dimensional plate model of cabinet structures is presented for the numerical verification of the proposed method. Experimental validation of the proposed method is carried out on a three-story frame which represents the structure of a cabinet. The SSE model of the frame is accurately identified by impact hammer tests with high fitness values over 85% of the actual frame characteristics. Shaking table tests are performed using El Centro, Kobe, and Northridge earthquakes as input motions and the acceleration responses are measured. The responses of the model under the three earthquakes are predicted and then compared with the measured responses. The predicted and measured responses agree well with each other with fitness values of 65-75%. The proposed method is more advantageous over other methods that are based on finite element (FE) model updating since it is free from FE modeling errors. It will be especially effective for cabinet structures in nuclear power plants where conducting shaking table tests may not be feasible. Limitations of the proposed method are also discussed.

  17. Lactose tolerance test shortened to 30 minutes: an exploratory study of its feasibility and impact

    Directory of Open Access Journals (Sweden)

    José Luis Domínguez-Jiménez

    2014-06-01

    Full Text Available Introduction: Lactose malabsorption (LM is a very common condition with a high prevalence in our setting. Lactose tolerance test (LTT is a basic, affordable test for diagnosis that requires no complex technology. It has been recently shown that this test can be shortened to 3 measurements (baseline, 30 min, 60 min with no impact on final results. The purpose of our study was to assess the feasibility and benefits of LTT simplification and shortening to 30 min, as well as the financial impact entailed. Material and methods: A multicenter, observational study of consecutive patients undergoing LTT for LM suspicion. Patients received 50 g of lactose following a fasting period of 12 h, and had blood collected from a vein at all 3 time points for the measurement of blood glucose (mg/dl. Differences between the shortened and complete test forms were analyzed using McNemar's test. A comparison of blood glucose levels between patients with normal and abnormal results was performed using Student's T-test for independent mean values. Consistency was assessed using the kappa index. A p < 0.05 was considered to be statistically significant. Results: A total of 270 patients (69.6% females were included, with a mean age of 39.9 ± 16 years. LTT was abnormal for 151 patients (55.9%. We observed no statistically significant differences in baseline blood glucose levels between patients with normal and abnormal LTT results (p = 0.13; however, as was to be expected, such differences were obvious for the remaining time points (p < 0.01. Deleting blood glucose measurements at 60 minutes only led to overdiagnose LM (false positive results in 6 patients (2.22 %, with a kappa index of 0.95 (95% CI: 0.92-0.99 (p < 0.001 versus the complete test. Suppressing measurements at 60 min would have saved at least € 7,726. Conclusion: The shortening of LTT to only 2 measurements (baseline and 30-min hardly leads to any differences in final results, and would entail savings in

  18. Impact Analyses and Tests of Concrete Overpacks of Spent Nuclear Fuel Storage Casks

    International Nuclear Information System (INIS)

    A concrete cask is an option for spent nuclear fuel interim storage. A concrete cask usually consists of a metallic canister which confines the spent nuclear fuel assemblies and a concrete overpack. When the overpack undergoes a missile impact, which might be caused by a tornado or an aircraft crash, it should sustain an acceptable level of structural integrity so that its radiation shielding capability and the retrievability of the canister are maintained. A missile impact against a concrete overpack produces two damage modes, local damage and global damage. In conventional approaches, those two damage modes are decoupled and evaluated separately. The local damage of concrete is usually evaluated by empirical formulas, while the global damage is evaluated by finite element analysis. However, this decoupled approach may lead to a very conservative estimation of both damages. In this research, finite element analysis with material failure models and element erosion is applied to the evaluation of local and global damage of concrete overpacks under high speed missile impacts. Two types of concrete overpacks with different configurations are considered. The numerical simulation results are compared with test results, and it is shown that the finite element analysis predicts both local and global damage qualitatively well, but the quantitative accuracy of the results are highly dependent on the fine-tuning of material and failure parameters

  19. Assessment of the TASER XREP blunt impact and penetration injury potential using cadaveric testing.

    Science.gov (United States)

    Lucas, Scott R; McGowan, Joseph C; Lam, Tack C; Yamaguchi, Gary T; Carver, Matthew; Hinz, Andrew

    2013-01-01

    TASER International's extended range electronic projectile (XREP) is intended to be fired from a shotgun, impact a threat, and apply remote neuromuscular incapacitation. This study investigated the corresponding potential of blunt impact injury and penetration. Forty-three XREP rounds were deployed onto two male human cadaver torsos at impact velocities between 70.6 and 95.9 m/sec (232 and 315 ft/sec). In 42 of the 43 shots fired, the XREP did not penetrate the abdominal wall, resulting in superficial wounds only. On one shot, the XREP's nose section separated prematurely in flight, resulting in penetration. No bony fractures were observed with any of the shots. The viscous criterion (VC), blunt criterion (BC), and energy density (E/A) were calculated (all nonpenetrating tests, average ± 1 standard deviation: VC: 1.14 ± 0.94 m/sec, BC: 0.77 ± 0.15, E/A: 22.6 ± 4.15 J/cm(2)) and, despite the lack of injuries, were generally found to be greater than published tolerance values. PMID:23067043

  20. How Well Does the Latest Anthropomorphic Test Device Mimic Human Impact Responses?

    Science.gov (United States)

    Newby, N.; Somers, J. T.; Caldwell, E.; Gernhardt, M.

    2014-01-01

    One of the goals of the NASA Occupant Protection Group is to understand the human tolerance to dynamic loading. This knowledge has to come through indirect approaches such as existing human response databases, anthropometric test devices (ATD), animal testing, post-mortem human subjects, and models. This study investigated the biofidelity of the National Highway Traffic Safety Administration's ATD named the THOR (test device for human occupant restraint). If THOR responds comparably to humans, then it could potentially be used as a human surrogate to help validate space vehicle requirements for occupant protection. The THOR responses to frontal and spinal impacts (ranging from 8 to 12 G with rise times of 40, 70, and 100 ms) were measured and compared to human volunteer responses (95 trials in frontal and 58 in spinal) previously collected by the U. S. Air Force on the same horizontal impact accelerator. The impact acceleration profiles tested are within the expected range of multi-purpose crew vehicle (MPCV) landing dynamics. A correlation score was calculated for each THOR to human comparison using CORA (CORrelation and Analysis) software. A two-parameter beta distribution model fit was obtained for each dependent variable using maximum likelihood estimation. For frontal impacts, the THOR head x-acceleration peak response correlated with the human response at 8 and 10-G 100 ms but not 10-G 70 ms. The phase lagged the human response. Head z-acceleration was not correlated. Chest x-acceleration was in phase, had a higher peak response, and was well correlated with lighter subjects (Cora = 0.8 for 46 kg vs. Cora = 0.4 for 126 kg). Head x-displacement had a leading phase. Several subjects responded with the same peak displacement but the mean of the group was lower. The shoulder x-displacement was in phase but had higher peaks than the human response. For spinal impacts, the THOR head x-acceleration was not well correlated. Head and chest z-acceleration was in phase

  1. Quasi-static characterisation and impact testing of auxetic foam for sports safety applications

    Science.gov (United States)

    Duncan, Olly; Foster, Leon; Senior, Terry; Alderson, Andrew; Allen, Tom

    2016-05-01

    This study compared low strain rate material properties and impact force attenuation of auxetic foam and the conventional open-cell polyurethane counterpart. This furthers our knowledge with regards to how best to apply these highly conformable and breathable auxetic foams to protective sports equipment. Cubes of auxetic foam measuring 150 × 150 × 150 mm were fabricated using a thermo–mechanical conversion process. Quasi-static compression confirmed the converted foam to be auxetic, prior to being sliced into 20 mm thick cuboid samples for further testing. Density, Poisson’s ratio and the stress–strain curve were all found to be dependent on the position of each cuboid from within the cube. Impact tests with a hemispherical drop hammer were performed for energies up to 6 J, on foams covered with a polypropylene sheet between 1 and 2 mm thick. Auxetic samples reduced peak force by ∼10 times in comparison to the conventional foam. This work has shown further potential for auxetic foam to be applied to protective equipment, while identifying that improved fabrication methods are required.

  2. Simulating the Response of a Composite Honeycomb Energy Absorber. Part 2; Full-Scale Impact Testing

    Science.gov (United States)

    Fasanella, Edwin L.; Annett, Martin S.; Jackson, Karen E.; Polanco, Michael A.

    2012-01-01

    NASA has sponsored research to evaluate an externally deployable composite honeycomb designed to attenuate loads in the event of a helicopter crash. The concept, designated the Deployable Energy Absorber (DEA), is an expandable Kevlar(Registered TradeMark) honeycomb. The DEA has a flexible hinge that allows the honeycomb to be stowed collapsed until needed during an emergency. Evaluation of the DEA began with material characterization of the Kevlar(Registered TradeMark)-129 fabric/epoxy, and ended with a full-scale crash test of a retrofitted MD-500 helicopter. During each evaluation phase, finite element models of the test articles were developed and simulations were performed using the dynamic finite element code, LS-DYNA(Registered TradeMark). The paper will focus on simulations of two full-scale impact tests involving the DEA, a mass-simulator and a full-scale crash of an instrumented MD-500 helicopter. Isotropic (MAT24) and composite (MAT58) material models, which were assigned to DEA shell elements, were compared. Based on simulations results, the MAT58 model showed better agreement with test.

  3. Investigating the Impact of Convergent vs. Divergent Assessment on ESL Students’ Anxiety and Test Performance

    Directory of Open Access Journals (Sweden)

    Azar Saeedi Nasab

    2014-05-01

    Full Text Available Language assessment with its eye-catching nature, casts its spell on many researchers, spurring on them to study its telling role in different arenas. The present study with a closer look to the realm, keeps one eye on two fresh approaches in assessment, namely convergent and divergent, and the other one on anxiety in a bid to slash its negative impact on students’ performance. The researchers resort to a correlational method with Ex Post Facto design, along with different tests, to forward the foregoing aim; discovering and appraising the degree of relationship stands between the two variables. Analyzing data gathered in this hybrid research on 55 young Iranian male and female students in two schools, located in United Arab Emirates (UAE, the researchers reaped findings which bore witness to the main proposed hypotheses, illustrating that divergent assessment (DA was more effective in reducing learners’ test anxiety level in comparison with convergent assessment (CA which, in turn, led up to better performance in the participants. Some implications for EFL teachers, to include the similar strategies in their lesson plan, offered at the very end which is followed by proposing some new horizons for further studies and investigations.Keywords: Divergent Assessment, Convergent Assessment, Dynamic Assessment, Test Anxiety, Test Performance 

  4. Testing the Impact of a Pre-Instructional Digital Game on Middle-Grade Students' Understanding of Photosynthesis

    Science.gov (United States)

    Culp, Katherine McMillan; Martin, Wendy; Clements, Margaret; Lewis Presser, Ashley

    2015-01-01

    Rigorous studies of the impact of digital games on student learning remain relatively rare, as do studies of games as supports for learning difficult, core curricular concepts in the context of normal classroom practices. This study uses a blocked, cluster randomized controlled trial design to test the impact of a digital game, played as homework…

  5. CHARACTERISATION OF EPOXY BASED E-GLASS / CARBON REINFORCED POLYMER COMPOSITE LAMINATES SUBJECTED TO LOW VELOCITY IMPACT TEST (DROP WEIGHT)

    OpenAIRE

    Dr. H. K. Shivanand; Shankar, S.; S.Santhosh Kumar

    2013-01-01

    The purpose of this research work is to investigate experimentally the Drop weight Impact response of epoxy matrixed e-glass and carbon reinforced polymer laminated composites. Impact tests had been conducted to characterize the type and extent of damage observed in composite laminates configured for varying thickness.

  6. Testing and assessment of low alloy steel for marine application

    International Nuclear Information System (INIS)

    This paper is an account of the work carried out during the assessment of low alloy steel (WH-80) for marine application. The relevant acceptance criteria consulted during the process is DEFST AN 02-874 and a standard reference material. Assessment is based on the experimental results of the tests carried out for the steel. Testing comprised of mechanical (tensile, impact and hardness) tests, corrosion (immersion corrosion and stress corrosion cracking) tests, metallography test and weldability (weld joint strength, controlled thermal severity -CTS and Y -Groove) tests undertaken at various testing laboratories in Pakistan. The results obtained after testing have been compared with acceptance criteria (DEFSTAN 02-874 and standard reference material). Moreover results have been compared with contemporary steels used for marine applications. Results showed a reasonable agreement with results available in literature for other low alloy steels with respect to mechanical strength and weldability. Steel weldments qualified the weld joint strength tests and weldability tests. Toughness has been measured at various temperatures. Results revealed that the toughness of base metal is higher than heat affected zone (HAZ) and weld metal. In weldability tests, weld metal and HAZ were examined microscopically to investigate integrity of weld. No cracks have been observed in the weld which indicates complete diffusion in to the welding material. WH- 80 steel has exhibited comparatively high corrosion rate, reduction in tensile strength during SCC test and low Charpy energy values at -50 degree C. It is therefore concluded that the WH-80 steel is unsuitable for use in application at subzero (OC) temperatures and in highly corrosive environment. (author)

  7. Genetic testing for Lynch syndrome in the first year of colorectal cancer: a review of the psychological impact

    OpenAIRE

    Landsbergen, Karin M.; Prins, Judith B; Brunner, Han G.; Kraaimaat, Floris W.; Hoogerbrugge, Nicoline

    2009-01-01

    An increasing number of patients with colorectal cancer (CRC) receive genetic counselling within 1 year after diagnosis. Little is known whether specific subgroups are more vulnerable for genetic testing related distress. A literature review was conducted to identify the psychological impact of CRC in the first year, and the additional impact of genetic testing. The electronic databases of PubMed, PsychInfo, Embase and the Cochrane Library were searched to identify all reports published betwe...

  8. Standard Test Method for Determining Resistance of Photovoltaic Modules to Hail by Impact with Propelled Ice Balls

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method provides a procedure for determining the ability of photovoltaic modules to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. 1.2 This test method defines test specimens and methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, provides a method for determining changes in electrical performance, and specifies parameters that must be recorded and reported. 1.3 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice ball impact resistance is beyond the scope of this test method. 1.4 The size of the ice ball to be used in conducting this test is not specified. This test method can be used with various sizes of ice balls. 1.5 This test method may be applied to concentrator and nonconcentrator modules. 1.6 The v...

  9. Characterisation of weldment hardness, impact energy and microstructure in API X65 steel

    International Nuclear Information System (INIS)

    The variation of microstructure and mechanical properties in various sub-zones of double submerged arc welded line pipe steel of grade API X65 was investigated. Instrumented Charpy V-notch tests and Vickers hardness experiments were conducted on the fusion zone, base metal and heat affected zone of the weld joint in 14.3 mm thick, 1219 mm outside diameter spiral pipeline. The lowest impact energy and the highest hardness level (160J and 218 HV, respectively) were recorded in the fusion zone. The low energy and high hardness characteristics of the seam weld can be attributed to its cast microstructure and the presence of grain boundary phases (such as proeutectoid ferrite), confirmed by standard metallographic observation. Despite this, service requirements set by the API 5L industry code (minimum impact energy of 73J, maximum hard spots of 350 HV) were fulfilled by the tested steel. Highlights: ► Experimental study of API X65 steel microstructure. ► Analysis of the relationship between X65 steel microstructure and hardness. ► Analysis of the relationship between X65 steel microstructure and impact energy. ► Presentation of detailed technical information on DSA welding in spiral pipes.

  10. SCK-CEN Contribution to the''Relation between different measures of exposure-induced shifts in ductile-brittle transition temperatures'' (REFEREE). Progress Report

    International Nuclear Information System (INIS)

    The relationship between Charpy-V (CVN) impact, fracture toughness and tensile properties for selected reactor pressure -vessel steels in the transition temperature range are investigated. Data on the testing of unirradiated material are reported. The applied methods include chemical analysis, Charpy-V impact testing, tensile testing and fracture toughness determination

  11. The effect of esthetic fibers on impact resistance of a conventional heat-cured denture base resin.

    Science.gov (United States)

    Doğan, Orhan Murat; Bolayir, Giray; Keskin, Selda; Doğan, Arife; Bek, Bülent; Boztuğ, Ali

    2007-03-01

    This study was conducted to observe the changes in impact resistance of a denture base resin reinforced with five types of fiber. E-glass, polyester, rayon, nylon 6, and nylon 6/6 fibers were cut into 2, 4, and 6 mm lengths and added into the resin at a concentration of 3% by weight. Five test specimens for each formulation, as well as control specimens without fiber, were prepared using a mold including a V-shaped notch with 55 x 10 x10 mm dimensions. Impact tests were carried out using a Charpy-type tester. Additionally, surfaces of the impact sections were observed under a scanning electron microscope (SEM). Results indicated that impact energy tended to increase with fiber length, and that the highest value was recorded for rayon fiber-reinforced specimens of 6 mm length. E-glass fiber reinforcement produced relatively stable, high values for each length, whereby good interfacial strength between polymer matrix and glass fibers was confirmed by SEM analysis. PMID:17621939

  12. HIV Testing Among Young People Aged 16-24 in South Africa: Impact of Mass Media Communication Programs.

    Science.gov (United States)

    Do, Mai; Figueroa, Maria Elena; Lawrence Kincaid, D

    2016-09-01

    Knowing one's serostatus is critical in the HIV prevention, care and treatment continuum. This study examines the impact of communication programs on HIV testing in South Africa. Data came from 2204 young men and women aged 16-24 who reported to be sexually active in a population based survey. Structural equation modeling was used to test the directions and causal pathways between communication program exposure, HIV testing discussion, and having a test in the last 12 months. Bivariate and multivariate probit regressions provided evidence of exogeneity of communication exposure and the two HIV-related outcomes. One in three sampled individuals had been tested in the last 12 months. Communication program exposure only had an indirect effect on getting tested by encouraging young people to talk about testing. The study suggests that communication programs may create an environment that supports open HIV-related discussions and may have a long-term impact on behavior change. PMID:27102409

  13. Evaluation of the hazardous impact of landfill leachates by toxicity and biodegradability tests.

    Science.gov (United States)

    Kalcíková, G; Vávrová, M; Zagorc-Koncan, J; Gotvajn, A Zgajnar

    2011-01-01

    The aim of our research was to assess the ecotoxicity and biodegradability of leachates originating from two parts of a municipal landfill before and after biological treatment in the existing treatment plant. Biotests represent important tools for adequate environmental characterization of landfill leachates and could be helpful in reliable assessment and monitoring of the treatment plant efficiency. For ecotoxicity testing of landfill leachate before and after biological treatment, different organisms were chosen: the bacteria Vibrio fischeri, a mixed culture of activated sludge, duckweed Lemna minor, white mustard Sinapis alba, brine shrimp Artemia salina, and water flea Daphnia magna. For assessment of biodegradability, the method for determination of oxygen demand in a closed respirometer was used. The investigated leachates were heavily polluted, and in some cases, effluent limits were exceeded even after treatment. Results indicated that toxicity tests and physico-chemical parameters determined before and after treatment equivalently assess the efficiency of the existing treatment plant. However, the investigated leachates showed higher toxicity to Daphnia magna and especially to Lemna minor in contrast to Vibrio fischeri and Artemia salina (neither was sensitive to any of the leachates). No leachates were readily biodegradable. Experiments confirmed that the battery of toxicity tests should be applied for more comprehensive assessment of landfill leachate treatment and for reliable assessment of the treated leachate's subsequent environmental impact. It was confirmed that treated leachate, in spite of its better physico-chemical characteristics, still represents a potential environmental risk and thus should not be released into the environment. PMID:21970176

  14. Application of a PVDF-based stress gauge in determining dynamic stress–strain curves of concrete under impact testing

    International Nuclear Information System (INIS)

    Polyvinylidene fluoride (PVDF) piezoelectric material has been successfully applied in many engineering fields and scientific research. However, it has rarely been used for direct measurement of concrete stresses under impact loading. In this paper, a new PVDF-based stress gauge was developed to measure concrete stresses under impact loading. Calibrated on a split Hopkinson pressure bar (SHPB) with a simple measurement circuit of resistance strain gauges, the PVDF gauge was then used to establish dynamic stress–strain curves of concrete cylinders from a series of axial impact testing on a drop-hammer test facility. Test results show that the stress curves measured by the PVDF-based stress gauges are more stable and cleaner than that of the stress curves calculated with the impact force measured from a load cell

  15. Standard Test Method for Hail Impact Resistance of Aerospace Transparent Enclosures

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the determination of the impact resistance of an aerospace transparent enclosure, hereinafter called windshield, during hailstorm conditions using simulated hailstones consisting of ice balls molded under tightly controlled conditions. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements see Section 7.

  16. Variation of Modal Characteristics of Electrical Cabinet According to the Excitation Level in Impact Hammer Test

    International Nuclear Information System (INIS)

    There are many electrical cabinets in nuclear power plants. Safety-related equipment is typically seismic qualified before installation. Seismic qualification of equipment is possible when identifying the accurate dynamic characteristics of the equipment. According to the nature of the cabinet, the dynamic characteristics of the electrical cabinet vary nonlinearly with excitation level. This study analyzed the nonlinear variation of the dynamic properties of an actual cabinet. For the purpose of this study, a seismic monitoring system cabinet was selected as a specimen. The impact hammer tests were conducted to identify a variation of the dynamic characteristics of the specimen by increasing the impulse level. Modal identification technique was used to extract the modal properties of the cabinet from the measurements

  17. Impact of ANSI 2009 criteria for performance testing in TLD personnel monitoring

    International Nuclear Information System (INIS)

    External Quality Assurance in TLD Personnel Monitoring Service was initiated in 1985, for periodic performance evaluation of various TLD Laboratories through postal exercise. Presently, all the 16 laboratories involved in Personnel Monitoring Service are covered under QA exercise. Since beginning, American National Standards Institute (ANSI) criteria have been adopted for performance testing in QA exercise. Presently, ANSI 2001 performance criteria along with ISO trumpet curve analysis method are being used for performance evaluation. In 2009, ANSI modified the performance evaluation criteria and this study evaluates its impact and feasibility of implementation of ANSI 2009 criteria in the quality assurance program for personnel monitoring. The performance of some laboratories evaluated using both ANSI 2001 and ANSI 2009 criteria have been discussed. The study shows that the ANSI 2009 criteria is more stringent and encourages even distribution of bias and standard deviation. This can be implemented with suitable modifications for performance evaluation

  18. Impact of erosion testing aspects on current and future flight conditions

    Science.gov (United States)

    Gohardani, Omid

    2011-05-01

    High speed of aero vehicles including commercial and military aircraft, missiles, unmanned air vehicles, as well as conceptual aircraft of the future are imposing larger restrictions on the materials of these vehicles and highlight the importance of adequate quantification of material behavior and performance during different flight conditions. Erosion due to weather conditions and other present particles such as hydrometeors; rain, hail and ice, as well as sand, volcanic ash and dust resulting from residues in the atmosphere are eminent as hazardous on the structure of a flying vehicle and may adversely influence the lifecycle of the structure. This study outlines an extensive review of research efforts on erosion in aviation and provides a basis for comparison between different apparatus simulating rain erosion and their usage within the aerospace industry. The significant aspects of erosion testing and future prospects for erosion impact are further addressed for forthcoming generations of flying vehicles.

  19. A new method for testing pile by single-impact energy and P-S curve

    Institute of Scientific and Technical Information of China (English)

    许昭永; 段永康; 王彬; 胡毅力; 杨润海; 许峻; 赵晋明

    2004-01-01

    By studying the pile-formula and stress-wave methods (e.g., CASE method), the authors propose a new method fortesting piles using the single-impact energy and P-S curves. The vibration and wave figures are recorded, and thedynamic and static displacements are measured by different transducers near the top of piles when the pile is impacted by a heavy hammer or micro-rocket. By observing the transformation coefficient of driving energy (totalenergy), the consumed energy of wave motion and vibration and so on, the vertical bearing capacity for single pileis measured and calculated. Then, using the vibration wave diagram, the dynamic relation curves between the force(P) and the displacement (S) is calculated and the yield points are determined. Using the static-loading test, thedynamic results are checked and the relative constants of dynamic-static P-S curves are determined. Then the subsidence quantity corresponding to the bearing capacity is determined. Moreover, the shaped quality of the pilebody can be judged from the formation of P-S curves.

  20. He-cooled demo divertor: Design verification testing against mechanical impact loads

    International Nuclear Information System (INIS)

    A modular He-cooled divertor concept for DEMO has been developed at Karlsruhe Institute of Technology. The design goal is to achieve a DEMO-relevant high heat flux of 10 MW/m2. The reference design HEMJ (He-cooled modular divertor with multiple-jet cooling) uses small finger modules, which consist of a tungsten tile and a thimble made of tungsten alloy. Both components are connected by soldering. They are cooled by helium gas (10 MPa, 634 °C) impinging directly onto the inner heated surface of the thimble. One of the most difficult to predict incident events is the disruption that may damage the divertor structure by an extraordinary impact loading. This danger is particularly acute by the brittle property of the tungsten material, which is generally characterized by the DBTT. In this paper an estimate of the mechanical impact loading induced by electro-magnetic forces during a disruption and an appropriate experimental setup are outlined, and the test results discussed.

  1. Numerical simulation of impact bend tests on araldite B and steel specimens

    International Nuclear Information System (INIS)

    As a preliminary stage in the numerical simulation of impact bend tests on elastic-plastic sample materials some simpler experiments were calculated for this report, some of which occured without crack propagation, others with linear elastic crack propagation. These calculations were performed with an own program based on the method of finite differences and also with the finite element program ADINA. In the numerical models plane stress was assumed. Crack propagation was governed by a relation between crack velocity and stress intensity factor. As load input the measured hammer load was used in some cases, mass and initial velocity of the hammer in others. The sample looses contact to the anvils and to the hammer for some time, which had to be considered in model building. The stiffening of the model in the contact region caused by the discretization had to be compensated by springs inserted between the sample and the anvils. The simulation reproduces the experimentally observed behaviour of the sample quite well. Furthermore, additional information can be extracted from the experiment, e.g. concerning the partition of the impact energy. (orig.)

  2. The Impact of Data-Based Science Instruction on Standardized Test Performance

    Science.gov (United States)

    Herrington, Tia W.

    Increased teacher accountability efforts have resulted in the use of data to improve student achievement. This study addressed teachers' inconsistent use of data-driven instruction in middle school science. Evidence of the impact of data-based instruction on student achievement and school and district practices has been well documented by researchers. In science, less information has been available on teachers' use of data for classroom instruction. Drawing on data-driven decision making theory, the purpose of this study was to examine whether data-based instruction impacted performance on the science Criterion Referenced Competency Test (CRCT) and to explore the factors that impeded its use by a purposeful sample of 12 science teachers at a data-driven school. The research questions addressed in this study included understanding: (a) the association between student performance on the science portion of the CRCT and data-driven instruction professional development, (b) middle school science teachers' perception of the usefulness of data, and (c) the factors that hindered the use of data for science instruction. This study employed a mixed methods sequential explanatory design. Data collected included 8th grade CRCT data, survey responses, and individual teacher interviews. A chi-square test revealed no improvement in the CRCT scores following the implementation of professional development on data-driven instruction (chi 2 (1) = .183, p = .67). Results from surveys and interviews revealed that teachers used data to inform their instruction, indicating time as the major hindrance to their use. Implications for social change include the development of lesson plans that will empower science teachers to deliver data-based instruction and students to achieve identified academic goals.

  3. Hydraulic impact end effector final test report. Automation and robotics section, ER/WM-AT Program

    Energy Technology Data Exchange (ETDEWEB)

    Couture, S.

    1994-02-18

    One tool being developed for dislodging and fragmenting the hard salt cake waste in the single-shell nuclear waste tanks at the Hanford Reservation near Richland, Washington, is the hydraulic impact end effector (HIEE). This total operates by discharging 11-in. slugs of water at ultrahigh pressures. The HIEE was designed, built, and initially tested in 1992. Work in 1993 included advanced developments of the HIEE to further investigate its fragmentation abilities and to determine more effective operating procedures. These tests showed that more fragmentation can be achieved by increasing the charge pressure of 40 kpsi to 55 kpsi and by the use of different operating procedures. The size of the material and the impact energy of the water slug fired from the HIEE are believed to be major factors in material fragmentation. The material`s ability to fracture also appears to depend on the distance a fracture or crack line must travel to a free surface. Thus, larger material is more difficult to fracture than smaller material. Discharge pressures of 40 kpsi resulted in little penetration or fracturing of the material. At 55 kpsi, however, the size and depth of the fractures increased. Nozzle geometry had a significant effect on fragment size and quantity. Fragmentation was about an order of magnitude greater when the HIEE was discharged into drilled holes rather than onto the material surface. Since surface shots tend to create craters, a multi-shot procedure, coupled with an advanced nozzle design, was used to drill (crater) deep holes into large material. With this procedure, a 600-lb block was reduced to smaller pieces without the use of any additional equipment. Through this advanced development program, the HIEE has demonstrated that it can quickly fragment salt cake material into small, easily removable fragments. The HIEE`s material fragmentation ability can be substantially increased through the use of different nozzle geometries and operating procedures.

  4. Hydraulic impact end effector final test report. Automation and robotics section, ER/WM-AT Program

    International Nuclear Information System (INIS)

    One tool being developed for dislodging and fragmenting the hard salt cake waste in the single-shell nuclear waste tanks at the Hanford Reservation near Richland, Washington, is the hydraulic impact end effector (HIEE). This total operates by discharging 11-in. slugs of water at ultrahigh pressures. The HIEE was designed, built, and initially tested in 1992. Work in 1993 included advanced developments of the HIEE to further investigate its fragmentation abilities and to determine more effective operating procedures. These tests showed that more fragmentation can be achieved by increasing the charge pressure of 40 kpsi to 55 kpsi and by the use of different operating procedures. The size of the material and the impact energy of the water slug fired from the HIEE are believed to be major factors in material fragmentation. The material's ability to fracture also appears to depend on the distance a fracture or crack line must travel to a free surface. Thus, larger material is more difficult to fracture than smaller material. Discharge pressures of 40 kpsi resulted in little penetration or fracturing of the material. At 55 kpsi, however, the size and depth of the fractures increased. Nozzle geometry had a significant effect on fragment size and quantity. Fragmentation was about an order of magnitude greater when the HIEE was discharged into drilled holes rather than onto the material surface. Since surface shots tend to create craters, a multi-shot procedure, coupled with an advanced nozzle design, was used to drill (crater) deep holes into large material. With this procedure, a 600-lb block was reduced to smaller pieces without the use of any additional equipment. Through this advanced development program, the HIEE has demonstrated that it can quickly fragment salt cake material into small, easily removable fragments. The HIEE's material fragmentation ability can be substantially increased through the use of different nozzle geometries and operating procedures

  5. Quantitative studies on impact resistance of reinforced concrete panels with steel liners under impact loading. Part 2: Analytical study for small-scale and full-scale tests

    International Nuclear Information System (INIS)

    In recent years design methods for impact-resistant concrete structures subjected to impact loads caused by an aircraft crash have become of considerable interest. Muto et al. performed impact tests on reinforced concrete slabs using an aircraft engine missile and evaluated certain critical design slab thicknesses such as perforation thickness and scabbing thickness. Taking actual construction conditions of roof slabs into consideration, they also qualitatively studied the beneficial influence of a deck-plate attached to the rear of the slab in preventing scatter of scabbed concrete. Other studies have also been carried out, such as those by the UKAEA and Walter where the effect of a liner attached to a rear surface is assessed in terms of an equivalent concrete slab thickness. However, there have been no quantitative studies of liner effect considered in the time domain. However, Kasai et al. made a quantitative appraisal of liner benefit for local damage from the impact of a rigid missile on a reinforced concrete (R/C) panel with a steel plate on the rear side from impact tests using a scale model. Furthermore, Morikawa et al. have drawn attention to the use of the discrete element method (DEM) for modeling local damage phenomena accompanying rear-face scabbing or penetration into the reinforced concrete panel. They demonstrated that impact phenomena could be assessed qualitatively. Koshika et al. also described a method for establishing parameters for a DEM analysis, making feasible a quantitative assessment of local damage to R/C panels. Based on this background, this paper takes the impact tests by a rigid projectile reported in Part I, and demonstrates that the difference in damage to an R/C panel with and without a steel liner plate may be simulated analytically. The impact test results of Muto et al. for the real engine impacting an R/C panel with a steel liner are then analyzed, and it is demonstrated that even for the full-size impact from a real engine

  6. Phase transformation and impact properties in the experimentally simulated weld heat-affected zone of a reduced activation ferritic/martensitic steel

    International Nuclear Information System (INIS)

    In this work, the phase transformation and impact properties in the weld heat-affected zone (HAZ) of a reduced activation ferritic/martensitic (RAFM) steel are investigated. The HAZs were experimentally simulated using a Gleeble simulator. The base steel consisted of tempered martensite through normalizing at 1000 °C and tempering at 750 °C, while the HAZs consisted of martensite, δ-ferrite and a small volume of autotempered martensite. The impact properties using a Charpy V-notch impact test revealed that the HAZs showed poor impact properties due to the formation of martensite and δ-ferrite as compared with the base steel. In addition, the impact properties of the HAZs further deteriorated with an increase in the δ-ferrite fraction caused by increasing the peak temperature. The impact properties of the HAZs could be improved through the formation of tempered martensite after post weld heat treatment (PWHT), but they remained lower than that of the base steel because the δ-ferrite remained in the tempered HAZs

  7. Effects of the neutronic irradiation on the impact tests. Efectos de la irradiacion neutronica sobre los ensayos de resiliencia

    Energy Technology Data Exchange (ETDEWEB)

    Lapea, J.; Perosanz, F.J.; Hernandez, M.T.

    1993-01-01

    The changes that the Charpy curves suffer when steel is exposed to neutronic fluence are studied. Three steels with different chemical composition were chosen, two of them (JPF and JPJ) being treated at only one neutronic fluence, while the last one (JRQ) was irradiated at three fluences. In this way, it was possible to compare the effect of increasing the neutronic dose, and to study the experimental results as a function of the steel chemical composition. Two characteristic facts have been observed: the displacement of the curve at higher temperatures, and decrease of the upper shelf energy (USE). The mechanical recovery of the materials after two different thermal treatments is also described, and a comparation between the experimental results obtained and the damage prediction formulas given by different regulatory international organisms in the nuclear field is established. Author. 11 refs.

  8. Effect of phosphorous and boron addition on microstructural evolution and Charpy impact properties of high-phosphorous-containing plain carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seokmin [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Shin, Sang Yong [Microstructure Physics and Alloy Design, Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf D-40237 (Germany); Lee, Junghoon [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Lee, Chang-Hoon [Next Generation Products Research Group, Technical Research Laboratories, POSCO, Pohang 790-785 (Korea, Republic of); Lee, Sunghak, E-mail: shlee@postech.ac.kr [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2013-03-01

    Four plain carbon steels were fabricated by controlling the addition of P and B, and then isothermal heat-treatments were conducted at 550 °C and 650 °C for 3 h on these steels to make ferrite–pearlite-based or ferrite–bainite-based microstructures, respectively. B was added for controlling the reduction in toughness due to grain boundary segregation of P because B was readily distributed on grain boundaries. In the 550 °C-treated steels, bainite grains were refined by the B addition, whereas the 650 °C-treated steels did not show the grain refinement due to the B addition. According to the critical time analysis for non-equilibrium grain boundary segregation of P and B, the present isothermal treatment time of 3 h was too short for the grain boundary segregation of P, and thus the fracture occurred mostly in a cleavage mode, instead of an intergranular mode. Since this 3 h-treatment time was too long for the grain boundary segregation of B, the grain boundary segregation of B was reduced, and the precipitation of cementites was promoted. In the 550 °C-treated steels, the area fraction of intergranular fracture increased with increasing volume fraction of grain boundary cementites, as they played an important role in initiating the intergranular fracture, although the area fraction of intergranular fracture was lower than 5%. In the 650 °C-treated steels having coarse grains, however, grain boundary cementites did not work for intergranular fracture because the crack readily propagated in a cleavage mode.

  9. Standard Test Method for Impact Resistance of Monolithic Polycarbonate Sheet by Means of a Falling Weight

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1995-01-01

    1.1 This test method covers the determination of the energy required to initiate failure in monolithic polycarbonate sheet material under specified conditions of impact using a free falling weight. 1.2 Two specimen types are defined as follows: 1.2.1 Type A consists of a flat plate test specimen and employs a clamped ring support. 1.2.2 Type B consists of a simply supported three-point loaded beam specimen (Fig. 1) and is recommended for use with material which can not be failed using the Type A specimen. For a maximum drop height of 6.096 m (20 ft) and a maximum drop weight of 22.68 kg (50 lb), virgin polycarbonate greater than 12.70 mm (1/2 in.) thick will probably require use of the Type B specimen. Note 1 - See also ASTM Methods: D 1709, D 2444 and D 3029. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of reg...

  10. The Impact of Truth Surrogate Variance on Quality Assessment/Assurance in Wind Tunnel Testing

    Science.gov (United States)

    DeLoach, Richard

    2016-01-01

    Minimum data volume requirements for wind tunnel testing are reviewed and shown to depend on error tolerance, response model complexity, random error variance in the measurement environment, and maximum acceptable levels of inference error risk. Distinctions are made between such related concepts as quality assurance and quality assessment in response surface modeling, as well as between precision and accuracy. Earlier research on the scaling of wind tunnel tests is extended to account for variance in the truth surrogates used at confirmation sites in the design space to validate proposed response models. A model adequacy metric is presented that represents the fraction of the design space within which model predictions can be expected to satisfy prescribed quality specifications. The impact of inference error on the assessment of response model residuals is reviewed. The number of sites where reasonably well-fitted response models actually predict inadequately is shown to be considerably less than the number of sites where residuals are out of tolerance. The significance of such inference error effects on common response model assessment strategies is examined.

  11. DebriSat: The New Hypervelocity Impact Test for Satellite Breakup Fragment Characterization

    Science.gov (United States)

    Cowardin, Heather

    2015-01-01

    To replicate a hyper-velocity fragmentation event using modern-day spacecraft materials and construction techniques to better improve the existing DoD and NASA breakup models: DebriSat is intended to be representative of modern LEO satellites. Major design decisions were reviewed and approved by Aerospace subject matter experts from different disciplines. DebriSat includes 7 major subsystems. Attitude determination and control system (ADCS), command and data handling (C&DH), electrical power system (EPS), payload, propulsion, telemetry tracking and command (TT&C), and thermal management. To reduce cost, most components are emulated based on existing design of flight hardware and fabricated with the same materials. center dotA key laboratory-based test, Satellite Orbital debris Characterization Impact Test (SOCIT), supporting the development of the DoD and NASA satellite breakup models was conducted at AEDC in 1992. Breakup models based on SOCIT have supported many applications and matched on-orbit events reasonably well over the years.

  12. Development of a shock wave adhesion test for composite bonds by laser pulsed and mechanical impacts

    Science.gov (United States)

    Ecault, Romain; Boustie, Michel; Touchard, Fabienne; Arrigoni, Michel; Berthe, Laurent; CNRS Collaboration

    2013-06-01

    Evaluating the bonding quality of composite material is becoming one of the main challenges faced by aeronautic industries. This work aims the development of a technique using shock wave, which would enable to quantify the bonding mechanical quality. Laser shock experiments were carried out. This technique enables high tensile stress generation in the thickness of composite bond without any mechanical contact. The resulting damage has been quantified using different method such as confocal microscopy, ultrasound and cross section observation. The discrimination between a correct bond and a weak bond was possible thanks to these experiments. Nevertheless, laser sources are not well adapted for optimization of such a test since it has often fixed parameters. That is why mechanical impacts bonded composites were also performed in this work. By changing the thickness of aluminum projectiles, the tensile stresses generated by the shock wave propagation were moved toward the composite/bond interface. The observations made prove that the optimization of the technique is possible. The key parameters for the development of a bonding test using shock wave have been identified.

  13. Development of a shock wave adhesion test for composite bonds by pulsed laser and mechanical impacts

    Science.gov (United States)

    Ecault, R.; Boustie, M.; Touchard, F.; Arrigoni, M.; Berthe, L.

    2014-05-01

    Evaluating the bonding quality of composite material is becoming one of the main challenges faced by aeronautic industries. This work aims to the development of a technique using shock wave, which would enable to quantify the bonding mechanical quality. Laser shock experiments were carried out. This technique enables high tensile stress generation in the thickness of composite bonds. The resulting damage has been quantified using different methods such as confocal microscopy, ultrasound and cross section observation. The discrimination between a correct bond and a weak bond was possible thanks to these experiments. Nevertheless, laser sources are not well adapted for optimization of such a test because of often fixed settings. That is why mechanical impacts on bonded composites were also performed in this work. By changing the thickness of aluminum projectiles, the generated tensile stresses by the shock wave propagation were moved toward the composite/bond interface. The made observations prove that the technique optimization is possible. The key parameters for the development of a bonding test using shock waves have been identified.

  14. Impact of geothermal well testing on exposed vegetation in the Northern Negros Geothermal Project, Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Tuyor, J.B.; Jesus, A.C. de; Medrano, R.S.; Garcia, J.R.D.; Salinio, S.M.; Santos, L.S. [PNOC Energy Development Corporation, Fort Bonifacio (Philippines)

    2005-04-01

    The impact of geothermal fluid discharges during the testing of Pataan 5-D well was evaluated on seedlings of mahogany (Swietenia macrophylla King) at various distances from the well and on natural forest vegetation around the wellpad. The parameters measured were: (1) geothermal brine spray concentration; (2) plant concentration of geothermal signature ions (B, Cl, Li and Na); (3) symptoms of plant damage; and (4) plant recovery. Meteorological parameters were also gathered. Adverse effects on the test plants were observed at distances of 5-50 m from the well silencer for over-spray during the horizontal discharge and at 50-350 m from the wellhead during the vertical discharge. Salinity was identified as a significant cause of plant damage. Observed symptoms of damage included drying of leaf tissues expressed as necrotic areas, which occurred first at the tip of older leaves and progressed along the margins as severity increased, resulting in abnormal defoliation. Recovery of seedlings and natural vegetation from sprays was observed in both vertical and horizontal discharges. (author)

  15. Torsion test technique for interfacial shear evaluation of F82H RAFM HIP-joints

    International Nuclear Information System (INIS)

    A hot isostatic press (HIP) process is a key technology to fabricate a first wall with cooling channels of the blanket system utilizing a reduced-activation ferritic/martensitic (RAFM) steel such as F82H. A primary objective of this study is to characterize interfacial properties of HIPed F82H joints by torsion to identify the feasibility of this test method for the inspection of the HIPed F82H joints. It is apparent that the absorption energies of the HIP joints varied by the processing conditions, although the maximum shear strength was not much different. The fracture surface observation study indicated that the reduction of the absorption energy obtained in the torsion tests was primarily due to the oxide formed on the interface of the HIP joint. Of particular importance, these features were very consistent with the results of Charpy impact tests. Preliminary test results then suggest that the torsion test method with a miniature specimen has a potential to evaluate the shear properties of the HIPed joint interface.

  16. Psychological and behavioural impact of genetic testing smokers for lung cancer risk: a phase II exploratory trial.

    Science.gov (United States)

    Sanderson, Saskia C; Humphries, Steve E; Hubbart, Christina; Hughes, Eluned; Jarvis, Martin J; Wardle, Jane

    2008-05-01

    The behavioural and psychological impact of genetic testing for lung cancer susceptibility was examined among smokers (N = 61) who were randomly allocated to a GSTM1 genetic testing group (with GSTM1-missing or GSTM1-present result) or no-test control group. The GSTM1-missing (higher risk) group reported greater motivation to quit smoking, and both genetic testing groups reported lower depression than the control group at one-week follow-up (p lifestyle-related genetic susceptibility tests. PMID:18420756

  17. Mechanical properties of medieval bloomery iron materials - comparative tensile and charpy-tests on bloomery iron samples and S235JRG2

    Czech Academy of Sciences Publication Activity Database

    Thiele, Á.; Hošek, Jiří

    2015-01-01

    Roč. 59, č. 1 (2015), s. 35-38. ISSN 0324-6051 R&D Projects: GA ČR GAP405/12/2289 Institutional support: RVO:67985912 Keywords : bloomery iron * phosphoric iron * mechanical properties * archaeometallurgy Subject RIV: AC - Archeology, Anthropology, Ethnology

  18. Impact of HFE genetic testing on clinical presentation of hereditary hemochromatosis: new epidemiological data

    Directory of Open Access Journals (Sweden)

    Ka Chandran

    2005-06-01

    Full Text Available Abstract Background Hereditary hemochromatosis (HH is a common inherited disorder of iron metabolism in Northern European populations. The discovery of a candidate gene in 1996 (HFE, and of its main mutation (C282Y, has radically altered the way to diagnose this disease. The aim of this study was to assess the impact of the HFE gene discovery on the clinical presentation and epidemiology of HH. Methods We studied our cohort of 415 patients homozygous for the C282Y allele and included in a phlebotomy program in a blood centre in western Brittany, France. Results In this cohort, 56.9% of the patients were male and 21.9% began their phlebotomy program before the implementation of the genetic test. A significant decrease in the sex ratio was noticed following implementation of this DNA test, from 3.79 to 1.03 (p -5, meaning that the proportion of diagnosed females relatives to males greatly increased. The profile of HH patients at diagnosis changed after the DNA test became available. Serum ferritin and iron values were lower and there was a reduced frequency of clinical signs displayed at diagnosis, particularly skin pigmentation (20.1 vs. 40.4%, OR = 0.37, p Conclusion This study highlights the importance of the HFE gene discovery, which has simplified the diagnosis of HH and modified its clinical presentation and epidemiology. This study precisely measures these changes. Enhanced diagnosis of HFE-related HH at an early stage and implementation of phlebotomy treatment are anticipated to maintain normal life expectancy for these patients.

  19. Impacts of transportation on a test and evaluation facility for nuclear waste disposal: a systems analysis

    International Nuclear Information System (INIS)

    An essential element of the Test and Evaluation Facility (TEF) is a waste packaging facility capable of producing a small number Test and Evaluation Facility of packages consisting of several different waste forms. The study envisions three scenarios for such a packaging facility: (1) modify an existing hot cell facility such as the Engine Maintenance Assembly and Disassembly (EMAD) facility at the Nevada Test Site so that it can serve as a packaging facility for the TEF. This scenario is referred to as the EMAD Option. (2) Build a new generic packaging facility (GPF) at the site of the TEF. In other words, colocate the GPF and the TEF. This scenario is referred to as the GPF Option, and (3) utilize the EMAD facility in conjunction with a colocated GPF (of minimal size and scope) at the TEF. This scenario is referred to as the Split Option. The results of the system study clearly bring out the fact that transportation has a significant impact on the selection and siting of the waste packaging facility. Preliminary conclusions, subject to the assumptions of the study, include the following: (1) regardless of the waste form, the GPF option is preferable to the other two in minimizing both transportation costs and logistical problems, (2) for any given scenario and choice of waste forms, there exists a candidate TEF location for which the transportation costs are at a minimum compared to the other locations, (3) in spite of the increased transportation costs and logistical complexity, the study shows that the overall system costs favor modification of an existing hot cell facility for the particular case considered

  20. Effect of ageing and specimen size on the impact properties of manet II steel

    International Nuclear Information System (INIS)

    Manet steel is one of the martensitic I 2%Cr-I%Mo-v steels family. These steels are used extensively in highly thermally stressed components, such as superheater tubing and main steam pipe systems in power stations, due to their adequate strength at high temperatures. In the present work the effect of ageing at 550 degree C for 1000 h on the impact properties of manet II steel was investigated. Two different Charpy V-notch impact specimens were used: full-size and sub size ones. Tests were carried out on two instrumental impact machines appropriate for the two specimen sizes. Both microstructure and fracture surface were examined using optical and scanning electron microscopy (SEM). The results showed that ageing produced little embrittling effect on MANET II steel. Both the ductile-to-brittle transition temperature (DBTT) and the brittleness transition temperature (TD) were increased by bout 15 degree C. The local fracture stress was also slightly reduced due to the ageing treatment. The results were discussed in the light of the chemical composition and the fracture surface morphology. 12 figs., 3 tabs

  1. Effects of manufacturing process on impact properties and microstructures of ODS steels

    International Nuclear Information System (INIS)

    Oxide dispersion strengthened (ODS) steels are notable advanced alloys with durability to a high-temperature and high-dose neutron irradiation environment because of their good swelling resistance and mechanical properties under neutron irradiation. 9–12Cr-ODS martensite steels have been developed in the Japan Atomic Energy Agency as the primary candidate material for the fast reactor fuel cladding tubes. They would also be good candidates for the fusion reactor blanket material which is exposed to high-dose neutron irradiation. In this work, modification of the manufacturing process of 11Cr-ODS steel was carried out to improve its impact property. Two types of 11Cr-ODS steels were manufactured: pre-mix and full pre-alloy ODS steels. Miniature Charpy impact tests and metallurgical observations were carried out on these steels. The impact properties of full pre-alloy ODS steels were shown to be superior to those of pre-mix ODS steels. It was demonstrated that the full pre-alloy process noticeably improved the microstructure homogeneity (i.e. reduction of inclusions and pores)

  2. Static and impact crack properties of a high-strength steel welded joint

    Energy Technology Data Exchange (ETDEWEB)

    Zrilic, M. [Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade (Serbia)]. E-mail: misa@tmf.bg.ac.yu; Grabulov, V. [Military Technical Institute, Ratka Resanovica 1, Belgrade (Serbia); Burzic, Z. [Military Technical Institute, Ratka Resanovica 1, Belgrade (Serbia); Arsic, M. [Institute for Material Testing, Bul. Vojvode Misica 43, Belgrade (Serbia); Sedmak, S. [Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade (Serbia)

    2007-03-15

    In order to gain the benefits of weldable high-strength steels in pressurized equipment applications, satisfactory toughness and crack properties of the welded joint, both in the weld metal and the heat-affected -zone (HAZ), are required. Experimental investigations of toughness and crack resistance parameters through static and impact tests of a high-strength, low-alloy steel (HSLA) with a nominal yield strength of 700 MPa and its welded joint, were performed on Charpy-sized specimens, V-notched and pre-cracked, of the parent metal, weld metal and HAZ. The selected electrode produced slight undermatching and enabled the welded joints to be manufactured without cold cracks. The impact energy and its parts responsible for crack initiation and propagation were determined by toughness evaluation. Crack sensitivity, defined as the ratio of the impact energy for V-notched and for pre-cracked specimens, enabled a comparison of the homogeneous microstructure of the parent metal and the weld metal, and of the heterogeneous microstructure of the heat-affected-zone (HAZ), which indicated a better crack toughness behaviour of the HAZ. The results obtained showed that the toughness and crack resistance of the weld metal were significantly lower than those of the parent metal and the HAZ. The fracture mechanics parameters, J {sub Ic} integral, and plane strain fracture toughness, K {sub Ic}, as well as J resistance curves expressed the degradation less.

  3. Impact of Genetic Counseling and Testing on Altruistic Motivations to Test for BRCA1/2: a Longitudinal Study.

    Science.gov (United States)

    Garg, Rahul; Vogelgesang, Joseph; Kelly, Kimberly

    2016-06-01

    Despite the importance of altruism in an individual's participation in genetic counseling and testing, little research has explored the change in altruistic motivations to test over time. This study analyzed altruistic motivations to test and change in altruistic motivations after genetic counseling and testing among individuals (N = 120) at elevated risk for BRCA1/2 mutations. The perceived benefits of genetic testing were assessed and utilized in a mixed-methods, repeated measures design at three time points: pre-counseling, counseling and post-genetic testing, along with transcripts of genetic counseling sessions. Qualitative analysis using an immersion/crystallization method resulted in six common perceived benefits of testing: cancer prevention, awareness, family's survival, relief from anxiety, for science, and future planning. Perceived benefits were then coded into three categories according to Hamilton's kin selection theory: altruistic motivation, personal motivation, and motivation for mutual benefit. At pre-counseling, those with a personal cancer history (p = 0.003) and those with one or more children (p = 0.013), were significantly more likely to cite altruistic motivations to test. Altruistic motivations significantly increased post-counseling (p = 0.01) but declined post-testing (p cancer to have altruistic motivations for testing. Genetic counseling may have increased altruistic motivations to help family and may be a prime opportunity to discuss other forms of altruism. PMID:26578231

  4. Lab-scale impact test to investigate the pipe-soil interaction and comparative study to evaluate structural responses

    Directory of Open Access Journals (Sweden)

    Ryu Dong-Man

    2015-07-01

    Full Text Available This study examined the dynamic response of a subsea pipeline under an impact load to determine the effect of the seabed soil. A laboratory-scale soil-based pipeline impact test was carried out to investigate the pipeline deformation/strain as well as the interaction with the soil-pipeline. In addition, an impact test was simulated using the finite element technique, and the calculated strain was compared with the experimental results. During the simulation, the pipeline was described based on an elasto-plastic analysis, and the soil was modeled using the Mohr-Coulomb failure criterion. The results obtained were compared with ASME D31.8, and the differences between the analysis results and the rules were specifically investigated. Modified ASME formulae were proposed to calculate the precise structural behavior of a subsea pipeline under an impact load when considering sand- and clay-based seabed soils.

  5. Development and validation of an instrument to measure the impact of genetic testing on self-concept in Lynch syndrome

    DEFF Research Database (Denmark)

    Esplen, M J; Stuckless, N; Gallinger, S;

    2011-01-01

    with two dimensions identified through factor analysis: stigma/vulnerability and bowel symptom-related anxiety. The scale showed excellent reliability (Cronbach's α = 0.93), good convergent validity by a high correlation with impact of event scale (r(102) = 0.55, p self-esteem scale......Esplen MJ, Stuckless N, Gallinger S, Aronson M, Rothenmund H, Semotiuk K, Stokes J, Way C, Green J, Butler K, Petersen HV, Wong J. Development and validation of an instrument to measure the impact of genetic testing on self-concept in Lynch syndrome. A positive genetic test result may impact...... on a person's self-concept and affect quality of life. The purpose of the study was to develop a self-concept scale to measure such impact for individuals carrying mutations for a heritable colorectal cancer Lynch syndrome (LS). Two distinct phases were involved: Phase 1 generated specific colorectal self...

  6. Lab-scale impact test to investigate the pipe-soil interaction and comparative study to evaluate structural responses

    Science.gov (United States)

    Ryu, Dong-Man; Lee, Chi-Seung; Choi, Kwang-Ho; Koo, Bon-Yong; Song, Joon-Kyu; Kim, Myung-Hyun; Lee, Jae-Myung

    2015-07-01

    This study examined the dynamic response of a subsea pipeline under an impact load to determine the effect of the seabed soil. A laboratory-scale soil-based pipeline impact test was carried out to investigate the pipeline deformation/strain as well as the interaction with the soil-pipeline. In addition, an impact test was simulated using the finite element technique, and the calculated strain was compared with the experimental results. During the simulation, the pipeline was described based on an elasto-plastic analysis, and the soil was modeled using the Mohr-Coulomb failure criterion. The results obtained were compared with ASME D31.8, and the differences between the analysis results and the rules were specifically investigated. Modified ASME formulae were proposed to calculate the precise structural behavior of a subsea pipeline under an impact load when considering sand- and clay-based seabed soils.

  7. The impact and hot tensile properties of 9Cr1Mo steel in various heat treatment conditions

    International Nuclear Information System (INIS)

    The impact and elevated temperature tensile properties of 9Cr1Mo in several heat treatment conditions have been studied to test the tolerance of the steel to departures from the material specification for AGR or fast reactor applications. The properties were found not to be sensitive to grain size or to the presence of grain boundary delta ferrite (<5%) which can arise in weld heat affected zones. Prior creep resulted in some loss of tensile strength but no loss of ductility was measured even though secondary precipitation had begun to develop under the conditions of the prior creep test. The dominant variable governing both tensile and impact properties was the state of temper and an empirical relationship was found between the tensile properties and hardness: the latter also being predictable by a Holloman-Jaffe form of expression. However, the Charpy impact properties of specimens aged near the service temperature (at 550 deg. C) were severely reduced by a mode of prior austenite grain boundary embrittlement manifested as severe intercrystalline failure. The embrittlement is of a type consistent with decohesion arising simply from equilibrium segregation (ie temper embrittlement). While the latter appears to make a significant contribution, interface decohesion is believed also to depend on concentration changes associated with carbide growth. (author)

  8. Preliminary draft: environmental impact statement for Hot Engineering Test Project at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    The project considered is the Hot Engineering Test Project (HETP), which is to be located in largely existing facilities at Oak Ridge National Laboratory (ORNL). The project is a part of the National High Temperature Gas-Cooled Reactor Fuel Recycle Program, which seeks to demonstrate the technological feasibility of the recycle processes. The HETP will attempt to confirm the operability of the processes (proven feasible in cold or nonradioactive, benchtop experimentation) under the more realistic radioactive condition. As such, the operation will involve the reprocessing and refabrication of spent HTGR fuel rods obtained from the Fort St. Vrain reactor. The reference fuel is highly enriched uranium. No significant radiological impacts are expected from routine operation of the facility to any biota or ecosystem. Concentrations of one or more radionuclides in Whiteoak Lake will increase as a result of the combination of HETP wastes with other ORNL wastes. Nonradiological effects from construction activities and routine operation should be insignificant on land and water use and on terrestrial and aquatic ecosystems. No significant socioeconomic impacts should occur from either construction or operation of the facility. Some conservative accident scenarios depict significant releases of radioactivity. Effects should be localized and would not be severe for all but the most unlikely of such incidents. No significant long-term commitment of resources is expected to be required for the project. Nor are any large quantities of scarce or critical resources likely to be irreversibly or irretrievably committed to the project. Principal alternatives considered were: relocation of the project site, postponement of the project schedule, project cancellation, and chemical process variations

  9. Climate Analogues for agricultural impact projection and adaptation – a reliability test

    Directory of Open Access Journals (Sweden)

    Swen P.M. Bos

    2015-10-01

    Full Text Available The climate analogue approach is often considered a valuable tool for climate change impact projection and adaptation planning, especially for complex systems that cannot be modelled reliably. Important examples are smallholder farming systems using agroforestry or other mixed-cropping approaches. For the projected climate at a particular site of interest, the analogue approach identifies locations where the current climate is similar to these projected conditions. By comparing baseline-analogue site pairs, information on climate impacts and opportunities for adaptation can be obtained. However, the climate analogue approach is only meaningful, if climate is a dominant driver of differences between baseline and analogue site pairs. For a smallholder farming setting on Mt. Elgon in Kenya, we tested this requirement by comparing yield potentials of maize and coffee (obtained from the IIASA Global Agro-ecological Zones dataset among 50 close analogue sites for different future climate scenarios and models, and by comparing local ecological knowledge and farm characteristics for one baseline-analogue pair.Yield potentials among the 50 closest analogue locations varied strongly within all climate scenarios, hinting at factors other than climate as major drivers of what the analogue approach might interpret as climate effects. However, on average future climatic conditions seemed more favourable to maize and coffee cultivation than current conditions. The detailed site comparison revealed substantial differences between farms in important characteristics, such as farm size and presence of cash crops, casting doubt on the usefulness of the comparison for climate change analysis. Climatic constraints were similar between sites, so that no apparent lessons for adaptation could be derived. Pests and diseases were also similar, indicating that climate change may not lead to strong changes in biotic constraints at the baseline site in the near future. From

  10. Ethics Standards Impacting Test Development and Use: A Review of 31 Ethics Codes Impacting Practices in 35 Countries

    Science.gov (United States)

    Leach, Mark M.; Oakland, Thomas

    2007-01-01

    Ethics codes are designed to protect the public by prescribing behaviors professionals are expected to exhibit. Although test use is universal, albeit reflecting strong Western influences, previous studies that examine the degree issues pertaining to test development and use and that are addressed in ethics codes of national psychological…

  11. Tensile and impact behaviour of a microalloyed medium carbon steel: Effect of the cooling condition and corresponding microstructure

    International Nuclear Information System (INIS)

    Highlights: ► Effect of different cooling rate after hot rolling in medium C microalloyed steels. ► Effect of microstructure on the impact toughness, at room and sub-zero temperatures. ► Brittle behavior induced by the fracture of large (Ti, V)(C, N) inclusions. ► Acicular ferrite deflects propagation cracks increasing impact toughness. -- Abstract: The effect of cooling rate after hot rolling on the final microstructure and mechanical properties of a microalloyed medium C steel was investigated. The microstructure was characterized by optical microscopy; the mechanical behavior was studied by hardness, tensile and instrumented Charpy V-notch impact tests carried out at room and sub-zero temperatures. The results of microstructural analysis indicate that a low cooling rate of 0.7 °C/s led to a mixed microstructure consisting of perlite, pro-eutectoid ferrite and bainite, while an increase of the cooling rate to 7.5 °C/s favored the formation of martensite and acicular ferrite. This latter microstructure, in turn, induced an increase in the tensile strength of the steel, with a reduction of its elongation to failure, and superior impact toughness. Analyses of the fracture surfaces with scanning electron microscopy confirmed the influence of the two microstructures on the failure mechanisms of the steel.

  12. The Arctic as a test case for an assessment of climate impacts on national security.

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Mark A.; Zak, Bernard Daniel; Backus, George A.; Ivey, Mark D.; Boslough, Mark Bruce Elrick

    2008-11-01

    The Arctic region is rapidly changing in a way that will affect the rest of the world. Parts of Alaska, western Canada, and Siberia are currently warming at twice the global rate. This warming trend is accelerating permafrost deterioration, coastal erosion, snow and ice loss, and other changes that are a direct consequence of climate change. Climatologists have long understood that changes in the Arctic would be faster and more intense than elsewhere on the planet, but the degree and speed of the changes were underestimated compared to recent observations. Policy makers have not yet had time to examine the latest evidence or appreciate the nature of the consequences. Thus, the abruptness and severity of an unfolding Arctic climate crisis has not been incorporated into long-range planning. The purpose of this report is to briefly review the physical basis for global climate change and Arctic amplification, summarize the ongoing observations, discuss the potential consequences, explain the need for an objective risk assessment, develop scenarios for future change, review existing modeling capabilities and the need for better regional models, and finally to make recommendations for Sandia's future role in preparing our leaders to deal with impacts of Arctic climate change on national security. Accurate and credible regional-scale climate models are still several years in the future, and those models are essential for estimating climate impacts around the globe. This study demonstrates how a scenario-based method may be used to give insights into climate impacts on a regional scale and possible mitigation. Because of our experience in the Arctic and widespread recognition of the Arctic's importance in the Earth climate system we chose the Arctic as a test case for an assessment of climate impacts on national security. Sandia can make a swift and significant contribution by applying modeling and simulation tools with internal collaborations as well as with

  13. External impact tests on communication systems for distribution automation; Gaibu impact ni taisuru jidoka system no shinraisei hyoka kenkyu (joho denso system ni tsuite)

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, K.; Nakamura, O. [Kansai Electric Power Co. Inc., Osaka (Japan); Gocho, Y. [Kansai Cable Service Co. Inc., Osaka (Japan)

    1996-01-31

    For the purpose of attaining high reliability in the design and construction of a distribution automation system, an evaluation was made on the reliability by grasping influence on the distribution automation system from various external impacts surrounding the system. Transmission methods then and presently used for distribution automation are the coaxial, the paired and the optical fiber cable systems; an examination was carried out on the performance limits of each system and on the ranges affected by the impacts on the system by allowing the respective equipment to be exposed to the severest possible external impacts that could be produced under testing conditions. The test items given for each system were total 59 items consisting of those for the coaxial (34 items), the paired (17 items) and the optical fiber (8 items), which were determined on the basis of the causes of fault from the actual cases in the past. The external impacts produced this time were far beyond the standards of the distribution department as well as the specifications on manufacturers` warranties, and therefore, each system was presumably of sufficient quality. Reliability assessment based on common test items (such as combustion, tensile strength, bending, submersion, etc.) ranked the optical cable system highest, the coaxial next, and the paired third. 10 figs., 4 tabs.

  14. Simulation analysis of impact tests of steel plate reinforced concrete and reinforced concrete slabs against aircraft impact and its validation with experimental results

    International Nuclear Information System (INIS)

    Highlights: • Simulation analysis is carried out with two constitutive concrete models. • Winfrith model can better simulate nonlinear response of concrete than CSCM model. • Performance of steel plate concrete is better than reinforced concrete. • Thickness of safety related structures can be reduced by adopting steel plates. • Analysis results, mainly concrete material models should be validated. - Abstract: The steel plate reinforced concrete and reinforced concrete structures are used in nuclear power plants for protection against impact of an aircraft. In order to compare the impact resistance performance of steel plate reinforced concrete and reinforced concrete slabs panels, simulation analysis of 1/7.5 scale model impact tests is carried out by using finite element code ANSYS/LS-DYNA. The damage modes of all finite element models, velocity time history curves of the aircraft engine and damage to aircraft model are compared with the impact test results of steel plate reinforced concrete and reinforced concrete slab panels. The results indicate that finite element simulation results correlate well with the experimental results especially for constitutive winfrith concrete model. Also, the impact resistance performance of steel plate reinforced concrete slab panels is better than reinforced concrete slab panels, particularly the rear face steel plate is very effective in preventing the perforation and scabbing of concrete than conventional reinforced concrete structures. In this way, the thickness of steel plate reinforced concrete structures can be reduced in important structures like nuclear power plants against impact of aircraft. It also demonstrates the methodology to validate the analysis procedure with experimental and analytical studies. It may be effectively employed to predict the precise response of safety related structures against aircraft impact

  15. Simulations of Pedestrian Impact Collisions with Virtual CRASH 3 and Comparisons with IPTM Staged Tests

    CERN Document Server

    Becker, Tony; Scurlock, Bob

    2015-01-01

    In this article, we present results from a series of Virtual CRASH-based pedestrian impact simulations. We compare the results of these Virtual CRASH pedestrian impact simulations to data from pedestrian impact collisions staged at the Institute of Police Technology and Management.

  16. Impact Strength of Austenitic and Ferritic-Austenitic Cr-Ni Stainless Cast Steel in -40 and +20°C Temperature

    Directory of Open Access Journals (Sweden)

    Kalandyk B.

    2014-10-01

    Full Text Available Studies described in this paper relate to common grades of cast corrosion resistant Cr-Ni steel with different matrix. The test materials were subjected to heat treatment, which consisted in the solution annealing at 1060°C followed by cooling in water. The conducted investigations, besides the microstructural characteristics of selected cast steel grades, included the evaluation of hardness, toughness (at a temperature of -40 and +20oC and type of fracture obtained after breaking the specimens on a Charpy impact testing machine. Based on the results of the measured volume fraction of ferrite, it has been found that the content of this phase in cast austenitic steel is 1.9%, while in the two-phase ferritic-austenitic grades it ranges from 50 to 58%. It has been demonstrated that within the scope of conducted studies, the cast steel of an austenitic structure is characterised by higher impact strength than the two-phase ferritic-austenitic (F-A grade. The changing appearance of the fractures of the specimens reflected the impact strength values obtained in the tested materials. Fractures of the cast austenitic Cr-Ni steel obtained in these studies were of a ductile character, while fractures of the cast ferritic-austenitic grade were mostly of a mixed character with the predominance of brittle phase and well visible cleavage planes.

  17. Impacts Analyses Supporting the National Environmental Policy Act Environmental Assessment for the Resumption of Transient Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    Annette L. Schafer; LLoyd C. Brown; David C. Carathers; Boyd D. Christensen; James J. Dahl; Mark L. Miller; Cathy Ottinger Farnum; Steven Peterson; A. Jeffrey Sondrup; Peter V. Subaiya; Daniel M. Wachs; Ruth F. Weiner

    2014-02-01

    This document contains the analysis details and summary of analyses conducted to evaluate the environmental impacts for the Resumption of Transient Fuel and Materials Testing Program. It provides an assessment of the impacts for the two action alternatives being evaluated in the environmental assessment. These alternatives are (1) resumption of transient testing using the Transient Reactor Test Facility (TREAT) at Idaho National Laboratory (INL) and (2) conducting transient testing using the Annular Core Research Reactor (ACRR) at Sandia National Laboratory in New Mexico (SNL/NM). Analyses are provided for radiologic emissions, other air emissions, soil contamination, and groundwater contamination that could occur (1) during normal operations, (2) as a result of accidents in one of the facilities, and (3) during transport. It does not include an assessment of the biotic, cultural resources, waste generation, or other impacts that could result from the resumption of transient testing. Analyses were conducted by technical professionals at INL and SNL/NM as noted throughout this report. The analyses are based on bounding radionuclide inventories, with the same inventories used for test materials by both alternatives and different inventories for the TREAT Reactor and ACRR. An upper value on the number of tests was assumed, with a test frequency determined by the realistic turn-around times required between experiments. The estimates provided for impacts during normal operations are based on historical emission rates and projected usage rates; therefore, they are bounding. Estimated doses for members of the public, collocated workers, and facility workers that could be incurred as a result of an accident are very conservative. They do not credit safety systems or administrative procedures (such as evacuation plans or use of personal protective equipment) that could be used to limit worker doses. Doses estimated for transportation are conservative and are based on

  18. Quantitative testing of robustness on super-omniphobic surfaces by drop impact

    CERN Document Server

    Nguyen, Thi Phuong Nhung; Coffinier, Yannick; Boukherroub, Rabah

    2010-01-01

    The quality of a liquid-repellent surface is quantified by both the apparent contact angle $\\theta_0$ that a sessile drop adopts on it, and the value of the liquid pressure threshold the surface can withstand without being impaled by the liquid, hence keeping a low-friction condition. We designed surfaces covered with nano-wires obtained by the vapor-liquid-solid (VLS) growth technique, that are able to repel most of the existing non-polar liquids including those of very low surface tension, as well as many polar liquids of moderate to high surface tension. These super-omniphobic surfaces exhibit apparent contact angles ranging from 125 to 160$^{\\circ}$ depending on the liquid. We tested the robustness of the surfaces against impalement by carrying out drop impact experiments. Our results show how this robustness depends on the Young's contact angle $\\theta_0$ related to the surface tension of the liquid, and that the orientational growth of NWs is a favorable factor for robustness.

  19. Experimental testing of impact force on rigid and flexible barriers - A comparison

    Science.gov (United States)

    Nagl, Georg; Hübl, Johannes; Chiari, Michael

    2016-04-01

    The Trattenbach endangers the main western railway track of Austria by floods and debris flows. Three check dams for debris retention were built in the proximal fan area several decades ago. With regard to an improvement of the protective function, these structures have to be renewed. The recent concept of the uppermost barrier is a type of an energy dissipation net structure, stopping debris flows with the ability of self-cleaning by subsequent floods or by machinery employment. The access to the basin is achieved through the slit when the net has been removed. This technical structure consists of a rigid open crown dam with a 4m wide slit. This slit is closed with a flexible net. To verify this protective system, 21 small scale experiments were conducted to test and optimize this new type of Slit Net Dam. To determine the forces on the barrier, in a first setup of experiments the impact forces on a rigid wall with 24 load cells were measured. In the second setup the slit barrier with the net was investigated. On four main cables the anchor forces were measured. In a further setup the basal distance between the channel and lowest net was varied. To study the emptying of the basin and the dosing effect on debris flows.

  20. Terahertz and Thermal Testing of Glass-Fiber Reinforced Composites with Impact Damages

    Directory of Open Access Journals (Sweden)

    T. Chady

    2012-01-01

    Full Text Available The studies on glass-fiber reinforced composites, due to their growing popularity and high diversity of industrial applications, are becoming an increasingly popular branch of the nondestructive testing. Mentioned composites are used, among other applications, in wind turbine blades and are exposed to various kinds of damages. The equipment reliability requirements force the development of accurate methods of their health monitoring. In this paper we present the study of composite samples with impact damages, using three methods: terahertz time domain inspection, active thermography with convective excitation, and active thermography with microwave excitation. The results of discrete Fourier transform of obtained time sequences of signals will be presented as well as some image processing of resulting amplitude and phase images. Proposed experimental methods combined with harmonic analysis are efficient tool of defects detection and allowed to detect flaws in examined specimens. Reader may find it interesting that in spite of differences in nature of applied experimental methods, one technique of signal processing (harmonic analysis gave adequate and comparable results in each case.

  1. Development of super simulator `IMPACT`. Pt. 2. Modeling of severe accident phenomena and initial verification tests

    Energy Technology Data Exchange (ETDEWEB)

    Miyagi, Kazumi; Vierow, K.M.; Naitoh, Masanori [Nuclear Power Engineering Corp., Tokyo (Japan); Hidaka, Masataka; Susuki, Akira; Ishida, Naoyuki; Yamagishi, Makoto; Abe, Nobuaki

    1998-05-01

    IMPACT employs advanced methods of physical modeling and numerical computation and can simulate a wide spectrum of scenarios ranging from normal operation to hypothetical, severe accidents. The simulator models major phenomena in the accident such as thermal hydraulics in the reactor cooling system (RCS), heat up of fuel rods, core melt, molten core relocation (freezing, slumping etc.), debris cooling in lower plenum, fission product (FP)s release and transport in RCS, steam explosion, debris/concrete interaction, thermal hydraulics in the containment vessel (CV), FPs transport in the CV. The modeling and combination of these phenomena could supply the ability to simulate the severe accident progress at Light Water Reactor. Initiated in fiscal year 1993, the project`s conceptual and detailed design phases have been completed and coding and verification phases are in progress. In the several analysis modules, verification studies for some modules are under way, and the steam explosion analysis module and the debris coolability analysis module are examined against typical experimental results to confirm the ability of each model. The premixing submodule for analysis of steam explosion phenomena under severe accident conditions has been completed, and was shown to simulate the MIXA tests well. Calculation results of debris spreading model in debris cooling process are compared with the experimental results and calculated average location of the spearhead at each time shows good agreement with the experimental observation, though spearhead shapes are different. (author)

  2. Consequences of exotic host use: impacts on Lepidoptera and a test of the ecological trap hypothesis.

    Science.gov (United States)

    Yoon, Su'ad; Read, Quentin

    2016-08-01

    Investigating the effects of invasive species on native biodiversity is one of the most pressing challenges in ecology. Our goal in this study was to quantify the effects of invasive plants on butterfly and moth communities. In addition, we sought to elucidate the fitness consequences of non-native hosts on lepidopterans. We conducted a meta-analysis on a total of 76 studies which provided data on larval performance, survival, oviposition preference, abundance, and species richness of Lepidoptera on native and exotic plants. Overwhelmingly, we found that performance and survival were reduced for larvae developing on exotic hosts, relative to native hosts. At the community level, alien plant invasion was associated with a reduction in the overall abundance and richness of lepidopteran communities. We found that lepidopterans did not show strong oviposition preference for native hosts. This result suggests that many invasive plant species may decrease lepidopteran abundance by providing a target for oviposition where larvae have a relatively poor chance of survival. Among studies that tested both survival and preference on exotic hosts, 37.5 % found evidence for novel hosts that could function as ecological traps (the figure was 18 % when considering studies that only assayed larval performance). Thus, although the majority of novel hosts included in our analyses are not likely to act as ecological traps, the potential clearly exists for this effect, and the role of ecological traps should be considered along with other aspects of global change impacting natural communities. PMID:26820566

  3. Reducing health impacts of biomass burning for cooking. The need for cookstove performance testing

    Energy Technology Data Exchange (ETDEWEB)

    Abeliotis, K. [Department of Home Economics and Ecology, Harokopio University, Athens (Greece); Pakula, C. [Institute of Agricultural Engineering, Section Household and Appliance Technology, Rheinische Friedrich-Wilhelms University, Bonn (Germany)

    2013-08-15

    Biomass is a renewable energy source that is routinely used for cooking in the developing world, especially in rural areas. The World Health Organization estimates that about 2.5 billion people globally rely on biomass, such as wood, agricultural waste and animal dung to meet their energy needs for cooking utilising traditional low-efficiency cookstoves. However, certain human health risks are associated with the inhalation of off-gases resulting from the indoor use of biomass for cooking, especially for women and children who spend more of their time at home. On the other hand, use of energy-efficient cookstoves is considered to reduce those risks. Thus, qualitative and quantitative measurements of cookstove performance are necessary in order to make different stoves and different cooking processes comparable. The aim of this paper is the presentation of the current situation regarding biomass use for cooking with emphasis placed on the developing world, the brief of the adverse health impacts of biomass burning based on the review of literature, the presentation of the merits of improved efficiency cookstoves and to highlight the need for stove performance tests. The demand of different types of biomass is not likely to change in the near future in the developing world since biomass is readily available and cheap. Thus, the efforts to improve household air quality must concentrate on improving cookstoves efficiency and ventilation of the flue gases outdoors. Programmes for the improvement of the cookstoves efficiency in the developing world should be part of the development agenda.

  4. Development of super simulator 'IMPACT'. Pt. 2. Modeling of severe accident phenomena and initial verification tests

    International Nuclear Information System (INIS)

    IMPACT employs advanced methods of physical modeling and numerical computation and can simulate a wide spectrum of scenarios ranging from normal operation to hypothetical, severe accidents. The simulator models major phenomena in the accident such as thermal hydraulics in the reactor cooling system (RCS), heat up of fuel rods, core melt, molten core relocation (freezing, slumping etc.), debris cooling in lower plenum, fission product (FP)s release and transport in RCS, steam explosion, debris/concrete interaction, thermal hydraulics in the containment vessel (CV), FPs transport in the CV. The modeling and combination of these phenomena could supply the ability to simulate the severe accident progress at Light Water Reactor. Initiated in fiscal year 1993, the project's conceptual and detailed design phases have been completed and coding and verification phases are in progress. In the several analysis modules, verification studies for some modules are under way, and the steam explosion analysis module and the debris coolability analysis module are examined against typical experimental results to confirm the ability of each model. The premixing submodule for analysis of steam explosion phenomena under severe accident conditions has been completed, and was shown to simulate the MIXA tests well. Calculation results of debris spreading model in debris cooling process are compared with the experimental results and calculated average location of the spearhead at each time shows good agreement with the experimental observation, though spearhead shapes are different. (author)

  5. Dual axis radiographic hydrodynamic test facility. Final environmental impact statement, Volume 2: Public comments and responses

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    On May 12, 1995, the U.S. Department of Energy (DOE) issued the draft Dual Axis Radiographic Hydrodynamic Test Facility Environmental Impact Statement (DARHT EIS) for review by the State of New Mexico, Indian Tribes, local governments, other Federal agencies, and the general public. DOE invited comments on the accuracy and adequacy of the draft EIS and any other matters pertaining to their environmental reviews. The formal comment period ran for 45 days, to June 26, 1995, although DOE indicated that late comments would be considered to the extent possible. As part of the public comment process, DOE held two public hearings in Los Alamos and Santa Fe, New Mexico, on May 31 and June 1, 1995. In addition, DOE made the draft classified supplement to the DARHT EIS available for review by appropriately cleared individuals with a need to know the classified information. Reviewers of the classified material included the State of New Mexico, the U.S. Environmental Protection Agency, the Department of Defense, and certain Indian Tribes. Volume 2 of the final DARHT EIS contains three chapters. Chapter 1 includes a collective summary of the comments received and DOE`s response. Chapter 2 contains the full text of the public comments on the draft DARHT EIS received by DOE. Chapter 3 contains DOE`s responses to the public comments and an indication as to how the comments were considered in the final EIS.

  6. Laboratory testing protocol for the impact of dispersed petrochemicals on seagrass

    International Nuclear Information System (INIS)

    Highlights: ► Seagrass were exposed to dispersed and non-dispersed crude and fuel oil. ► Dispersed oil led to significant reductions in photosynthetic health of seagrass. ► Non-dispersed oil resulted in only minor reductions in seagrass health. ► Testing protocol developed enables rapid comparisons of oil spill mitigation options. - Abstract: To improve the effectiveness of oil spill mitigation, we developed a rapid, logistically simple protocol to detect petrochemical stress on seagrass. Sections of leaf blades from Zostera muelleri subsp. capricorni were exposed to the water accommodated fraction (WAF) of non-dispersed and dispersed Tapis crude oil and fuel oil (IFO-380) for 5 h. Photosynthetic health was monitored by assessing changes in effective quantum yield of photosystem II (ΔF/Fm′) and chlorophyll a pigment concentrations. Loss of total petroleum hydrocarbons (TPH) was measured using an oil-in-water fluorometer, whilst GC–MS analyses quantified the hydrocarbon components within each treatment. Few significant differences were detected in the chlorophyll a pigment analyses; however, ΔF/Fm′ appeared sensitive to petrochemical exposure. Dispersing both types of oil resulted in a substantial increase in the TPH of the WAF and was generally correlated with a greater physiological impact to the seagrass health, compared with the oil alone.

  7. SCK-CEN participation to the IAEA CRP-8 - Area topic no. 2: ''Application of the master curve for dynamic testing''. Activity 2005

    International Nuclear Information System (INIS)

    The latest IAEA Co-ordinated Research Project (CRP-8) focuses on the application of the Master Curve approach to monitor fracture toughness of reactor pressure vessels in nuclear power power plants. Three main work areas have been identified: (a) constraint and geometry effects on Master Curve To values; (b) loading rate effects up to impact conditions; (c) potential changes of Master Curve shape for highly embrittled materials. After the kick-off meeting in Vienna in October 2004, the first Research Coordination Meeting was held in May 2005, hosted by AEKI Budapest. The present document focuses on the participation and contribution of SCK-CEN to Topic Area no. 2 (Loading rate effects on Master Curve - Impact Loading), for which E. Lucon acts as co-task leader. A Round-Robin exercise is planned for early 2006, consisting in 10 tests per participant on precracked Charpy-V specimen of JRQ, tested dynamically using an instrumented pendulum; the results will be analysed using the Master Curve procedure (ASTM E1921-05) and compared to data obtained at other loading rates (quasi-static and/or dynamic). Guidelines and detailed specifications have been produced and circulated after the meeting in Budapest. SCK-CEN has also produced data reporting sheets in EXCEL97 form, which will be used for reporting all fracture toughness test results (at quasi-static, dynamic or impact loading rates) performed in the framework of the CRP-8. (author)

  8. The Impact of Test Case Summaries on Bug Fixing Performance: An Empirical Investigation

    OpenAIRE

    Panichella, S.; Panichella, A.; Beller, M.; Zaidman, A.E.; Gall, H.

    2016-01-01

    Automated test generation tools have been widely investigated with the goal of reducing the cost of testing activities. However, generated tests have been shown not to help developers in detecting and finding more bugs even though they reach higher structural coverage compared to manual testing. The main reason is that generated tests are difficult to understand and maintain. Our paper proposes an approach, coined TestDescriber, which automatically generates test case summaries of the po...

  9. Finite element method for the simulation of impact tests on large-size bending test specimens of a pressure vessel steel

    International Nuclear Information System (INIS)

    Impact tests have been made on 3-point bending test specimens of the size 495x90x45 mm3 of a pressure vessel steel in order to verify the experimentally determined J-integral and the crack propagation Δa by the numerical finite element method. The model uses the impact hammer as the point mass, the contact area as the elastic spring, and the specimen as a two-dimensional FE model, and assumes a plane stress. The calculations have been made with explicit time integration, taking into account dynamic effects. The measured time curve of the hammer load in the initial phase could not be reproduced with the statically determined elastic-plastic stress-strain relation. Modelling is achievable assuming a viscoplastic material model with a fluid parameter γ = 100 s-1. With a strong entire deformation of the specimen being given, the measured hammer impact could be explained assuming a friction with a friction coefficient of 0.7. About 10 to 15% of the hammer impact energy is taken up at the bearing points, and considering this percentage, the experimental data and the numerically derived J(Δα) curve almost agree. After about 5 mm of crack propagation, the calculated J-integral increasingly depends on the integration area. This is assumed to be due to the fact that the energy density becomes explicitly dependent on position as a result of relieving processes. (orig.)

  10. Final Environmental Impact Statement for the Nevada Test Site and off- site locations in the state of Nevada: Reader's guide

    International Nuclear Information System (INIS)

    This Reader's Guide is designed to help you find information in the US Departments of Energy's Nevada Test Site Environmental Impact Statement (NTS EIS). This Guide is divided into four sections: an introduction to the NTS EIS, specific topics, number conversions and scientific notations and public reading room locations

  11. The Validity of Value-Added Estimates from Low-Stakes Testing Contexts: The Impact of Change in Test-Taking Motivation and Test Consequences

    Science.gov (United States)

    Finney, Sara J.; Sundre, Donna L.; Swain, Matthew S.; Williams, Laura M.

    2016-01-01

    Accountability mandates often prompt assessment of student learning gains (e.g., value-added estimates) via achievement tests. The validity of these estimates have been questioned when performance on tests is low stakes for students. To assess the effects of motivation on value-added estimates, we assigned students to one of three test consequence…

  12. Attention Network Test in adults with ADHD - the impact of affective fluctuations

    Directory of Open Access Journals (Sweden)

    Lundervold Astri J

    2011-07-01

    Full Text Available Abstract Background The Attention Network Test (ANT generates measures of different aspects of attention/executive function. In the present study we investigated whether adults with ADHD performed different from controls on measures of accuracy, variability and vigilance as well as the control network. Secondly, we studied subgroups of adults with ADHD, expecting impairment on measures of the alerting and control networks in a subgroup with additional symptoms of affective fluctuations. Methods A group of 114 adults (ADHD n = 58; controls n = 56 performed the ANT and completed the Adult ADHD Rating Scale (ASRS and the Mood Disorder Questionnaire (MDQ. The latter was used to define affective fluctuations. Results The sex distribution was similar in the two groups, but the ADHD group was significantly older (p = .005 and their score on a test of intellectual function (WASI significantly lower than in the control group (p = .007. The two groups were not significantly different on measures of the three attention networks, but the ADHD group was generally less accurate (p = .001 and showed a higher variability through the task (p = .033. The significance was only retained for the accuracy measure when age and IQ scores were controlled for. Within the ADHD group, individuals reporting affective fluctuations (n = 22 were slower (p = .015 and obtained a lower score on the alerting network (p = .018 and a higher score on the conflict network (p = .023 than those without these symptoms. The significance was retained for the alerting network (p = .011, but not the conflict network (p = .061 when we controlled for the total ASRS and IQ scores. Discussion Adults with ADHD were characterized by impairment on accuracy and variability measures calculated from the ANT. Within the ADHD group, adults reporting affective fluctuations seemed to be more alert (i.e., less impacted by alerting cues, but slower and more distracted by conflicting stimuli than the

  13. Putting social impact assessment to the test as a method for implementing responsible tourism practice

    NARCIS (Netherlands)

    McCombes, Lucy; Vanclay, Frank; Evers, Yvette

    2015-01-01

    The discourse on the social impacts of tourism needs to shift from the current descriptive critique of tourism to considering what can be done in actual practice to embed the management of tourism's social impacts into the existing planning, product development and operational processes of tourism b

  14. Study of austenitic stainless steel welded with low alloy steel filler metal. [tensile and impact strength tests

    Science.gov (United States)

    Burns, F. A.; Dyke, R. A., Jr.

    1979-01-01

    The tensile and impact strength properties of 316L stainless steel plate welded with low alloy steel filler metal were determined. Tests were conducted at room temperature and -100 F on standard test specimens machined from as-welded panels of various chemical compositions. No significant differences were found as the result of variations in percentage chemical composition on the impact and tensile test results. The weldments containing lower chromium and nickel as the result of dilution of parent metal from the use of the low alloy steel filler metal corroded more severely in a marine environment. The use of a protective finish, i.e., a nitrile-based paint containing aluminum powder, prevented the corrosive attack.

  15. Impacts Analyses Supporting the National Environmental Policy Act Environmental Assessment for the Resumption of Transient Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    Annette L. Schafer; Lloyd C. Brown; David C. Carathers; Boyd D. Christensen; James J. Dahl; Mark L. Miller; Cathy Ottinger Farnum; Steven Peterson; A. Jeffrey Sondrup; Peter V. Subaiya; Daniel M. Wachs; Ruth F. Weiner

    2013-11-01

    Environmental and health impacts are presented for activities associated with transient testing of nuclear fuel and material using two candidate test reactors. Transient testing involves irradiation of nuclear fuel or materials for short time-periods under high neutron flux rates. The transient testing process includes transportation of nuclear fuel or materials inside a robust shipping cask to a hot cell, removal from the shipping cask, pre-irradiation examination of the nuclear materials, assembly of an experiment assembly, transportation of the experiment assembly to the test reactor, irradiation in the test reactor, transport back to the hot cell, and post-irradiation examination of the nuclear fuel or material. The potential for environmental or health consequences during the transportation, examination, and irradiation actions are assessed for normal operations, off-normal (accident) scenarios, and transportation. Impacts to the environment (air, soil, and groundwater), are assessed during each phase of the transient testing process. This report documents the evaluation of potential consequences to the general public. This document supports the Environmental Assessment (EA) required by the U.S. National Environmental Policy Act (NEPA) (42 USC Subsection 4321 et seq.).

  16. The Impact of Test Case Summaries on Bug Fixing Performance: An Empirical Investigation

    NARCIS (Netherlands)

    Panichella, S.; Panichella, A.; Beller, M.; Zaidman, A.E.; Gall, H.

    2015-01-01

    Automated test generation tools have been widely investigated with the goal of reducing the cost of testing activities. However, generated tests have been shown not to help developers in detecting and finding more bugs even though they reach higher structural coverage compared to manual testing. The

  17. The impact of information order on intentions to undergo predictive genetic testing: an experimental study.

    Science.gov (United States)

    Morrison, Val; Henderson, Bethan J; Taylor, Caroline; A'Ch Dafydd, Nonn; Unwin, Abbie

    2010-10-01

    As predictive genetic testing availability increases so does our need to understand factors associated with test uptake. This study tests whether the order positive and negative information about genetic testing for breast cancer is presented in affects intention to take a genetic test. Eighty-four women were randomly allocated into three groups: (1) positive then negative information; (2) negative then positive information; and (3) a control group. A significant effect was found in relation to perceived risk, attitudes towards genetic testing, perceived disadvantages of testing and intention. Our findings point to a primacy effect, whereby information presented first has the greatest effect. PMID:20472604

  18. Evaluation of the same heat Hastelloy XR as the material used for high-temperature components of the High-Temperature Engineering Test Reactor, 2

    International Nuclear Information System (INIS)

    A series of tension, Charpy impact and creep tests was carried out on two sorts of plate materials with 15 mm and 60 mm in thickness obtained from typical one of 30 heats of Hastelloy XR manufactured as the component material of the High-Temperature Engineering Test Reactor (HTTR). Creep test temperatures were 850, 900, 950 and 1000degC, and the maximum creep test time was 3371.4 h. The results obtained are as follows: (1) Both of plate materials tested exhibit acceptable tensile strength and tensile ductility as the structural material of the high-temperature components of the HTTR. (2) The plate material with 15 mm in thickness exhibits enough toughness, while toughness of the plate material with 60 mm in thickness is inferior to that of the plate material with 15 mm in thickness. (3) Both of plate materials tested possess the creep rupture strength beyond not only the expected minimum stress-to-rupture values, SR, but also the expected mean stress-to-rupture values of the material strength standards of Hastelloy XR. The materials also possess enough creep rupture ductility. (author)

  19. Investigation on occupant ejection in high severity rear impact based on post mortem human subject sled tests.

    Science.gov (United States)

    Petit, Philippe; Luet, Carole; Potier, Pascal; Vallancien, Guy

    2011-11-01

    Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al. 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection. Extensive literature search has found no full-scale rear impact tests involving Post Mortem Human Subjects (PMHS) conducted in a laboratory environment and resulting in ejection. This paper describes a total of 10 sled tests conducted on 3 belted PMHS using a simplified seat design composed of rigid plates assembled such that the angular and linear stiffness of the seatback (including the foam) was modeled. The initial angular position and the range of motion of the seatback, the size of the PMHS, the slack length of the seatbelt, the angular stiffness of the seatback, and the use of headrest were varied in the test matrix while the pulse was kept constant (triangular acceleration with a peak of 17 G at 30 ms and a duration of 95 ms). In the test series, the tests were not run randomly but the likelihood of occupant ejection was increased systematically until ejection occurred. PMHS seat ejection was observed only for the 95th percentile, initially positioned with a seatback angle relative to the vertical equal to 22°, a range of seatback angular motion equal to 44° and no headrest. Repeating

  20. Test and Analysis Correlation of High Speed Impacts of Ice Cylinders

    Science.gov (United States)

    Fasanella, Edwin L.; Boitnott, Richard L.; Kellas, Sotiris

    2006-01-01

    During the space shuttle return-to-flight preparations following the Columbia accident, finite element models were needed that could predict the threshold of critical damage to the orbiter s wing leading edge from ice debris impacts. Hence, an experimental program was initiated to provide crushing data from impacted ice for use in dynamic finite element material models. A high-speed drop tower was configured to capture force time-histories of ice cylinders for impacts up to approximately 100 ft/s. At low velocity, the force-time history depended heavily on the internal crystalline structure of the ice. However, for velocities of 100 ft/s and above, the ice fractured on impact, behaved more like a fluid, and the subsequent force-time history curves were much less dependent on the internal crystalline structure.

  1. Numerical Tests on Failure Process of Rock Particle under Impact Loading

    OpenAIRE

    Yu-Jun Zuo; Qin Zhang; Tao Xu; Zhi-Hong Liu; Yue-Qin Qiu; Wan-Cheng Zhu

    2015-01-01

    By using numerical code RFPA2D (dynamic version), numerical model is built to investigate the failure process of rock particle under impact loading, and the influence of different impact loading on crushing effect and consumed energy of rock particle sample is analyzed. Numerical results indicate that crushing effect is good when the stress wave amplitude is close to the dynamic strength of rock; it is difficult for rock particle to be broken under too low stress wave amplitude; on the other ...

  2. Assessing the impact of common forensic presumptive tests on the ability to obtain results using a novel rapid DNA platform.

    Science.gov (United States)

    Donachie, Gillian E; Dawnay, Nick; Ahmed, Romana; Naif, Sarah; Duxbury, Nicola J; Tribble, Nicholas D

    2015-07-01

    The rise of DNA evidence to the forefront of forensic science has led to high sample numbers being submitted for profiling by investigators to casework laboratories: bottleneck effects are often seen resulting in slow turnaround times and sample backlog. The ParaDNA(®) Screening and Intelligence Tests have been designed to guide investigators on the viability of potential sources of DNA allowing them to determine which samples should be sent for full DNA analysis. Both tests are designed to augment the arsenal of available forensic tests for end users and be used concurrently to those commonly available. Therefore, assessing the impact that common forensic tests have on such novel technology is important to measure. The systems were tested against various potential inhibitors to which samples may be exposed as part of the investigative process. Presumptive test agents for biological materials (blood, semen and saliva) and those used as fingerprint enhancement agents were both used. The Screening Test showed a drop in performance following application of aluminium powder and cyanoacrylate (CNA) on fingerprints samples; however this drop in performance was not replicated with high template DNA. No significant effect was observed for any agent using the Intelligence Test. Therefore, both tests stand up well to the chemical agents applied and can be used by investigators with confidence that system performance will be maintained. PMID:25864157

  3. Test impact on the overall die-to-wafer 3D stacked IC cost

    NARCIS (Netherlands)

    Taouil, M.; Hamdioui, S.; Beenakker, K.; Marinissen, E.J.

    2011-01-01

    One of the key challenges in 3D Stacked-ICs (3D-SIC) is to guarantee high product quality at minimal cost. Quality is mostly determined by the applied tests and cost trade-offs. Testing 3D-SICs is very challenging due to several additional test moments for the mid-bond stacks, i.e., partially create

  4. An experiment to test advanced materials impacted by intense proton pulses at CERN HiRadMat facility

    CERN Document Server

    Bertarelli, A; Boccone, V; Carra, F; Cerutti, F; Charitonidis, N; Charrondiere, C; Dallocchio, A; Fernandez Carmona, P; Francon, P; Gentini, L; Guinchard, M; Mariani, N; Masi, A; Marques dos Santos, S D; Moyret, P; Peroni, L; Redaelli, S; Scapin, M

    2013-01-01

    Predicting the consequences of highly energetic particle beams impacting protection devices as collimators or high power target stations is a fundamental issue in the design of state-of-the-art facilities for high-energy particle physics. These complex dynamic phenomena can be successfully simulated resorting to highly non-linear numerical tools (Hydrocodes). In order to produce accurate results, however, these codes require reliable material constitutive models that, at the extreme conditions induced by a destructive beam impact, are scarce and often inaccurate. In order to derive or validate such models a comprehensive, first-of-its-kind experiment has been recently carried out at CERN HiRadMat facility: performed tests entailed the controlled impact of intense and energetic proton pulses on a number of specimens made of six different materials. Experimental data were acquired relying on embedded instrumentation (strain gauges, temperature probes and vacuum sensors) and on remote-acquisition devices (laser ...

  5. Impact and Cost-Effectiveness of Point-Of-Care CD4 Testing on the HIV Epidemic in South Africa.

    Directory of Open Access Journals (Sweden)

    Alastair Heffernan

    Full Text Available Rapid diagnostic tools have been shown to improve linkage of patients to care. In the context of infectious diseases, assessing the impact and cost-effectiveness of such tools at the population level, accounting for both direct and indirect effects, is key to informing adoption of these tools. Point-of-care (POC CD4 testing has been shown to be highly effective in increasing the proportion of HIV positive patients who initiate ART. We assess the impact and cost-effectiveness of introducing POC CD4 testing at the population level in South Africa in a range of care contexts, using a dynamic compartmental model of HIV transmission, calibrated to the South African HIV epidemic. We performed a meta-analysis to quantify the differences between POC and laboratory CD4 testing on the proportion linking to care following CD4 testing. Cumulative infections averted and incremental cost-effectiveness ratios (ICERs were estimated over one and three years. We estimated that POC CD4 testing introduced in the current South African care context can prevent 1.7% (95% CI: 0.4% - 4.3% of new HIV infections over 1 year. In that context, POC CD4 testing was cost-effective 99.8% of the time after 1 year with a median estimated ICER of US$4,468/DALY averted. In healthcare contexts with expanded HIV testing and improved retention in care, POC CD4 testing only became cost-effective after 3 years. The results were similar when, in addition, ART was offered irrespective of CD4 count, and CD4 testing was used for clinical assessment. Our findings suggest that even if ART is expanded to all HIV positive individuals and HIV testing efforts are increased in the near future, POC CD4 testing is a cost-effective tool, even within a short time horizon. Our study also illustrates the importance of evaluating the potential impact of such diagnostic technologies at the population level, so that indirect benefits and costs can be incorporated into estimations of cost-effectiveness.

  6. A test to evaluate the physical impact on technical performance in soccer

    DEFF Research Database (Denmark)

    Rostgaard, Thomas; Iaia, F. Marcello; Simonsen, Dennis S.;

    2008-01-01

    The aim of the study was to develop and examine a test for evaluation of the physical and technical capacity of soccer players. Fourteen youth elite (YE) and seven sub-elite (SE) players performed a physical and technical test (PT-test) consisting of 10 long kicks interspersed with intense...... intermittent exercise. In addition, a control test (CON-test) without intense exercise was performed. In both cases, the test result was evaluated by the precision of the 10 kicks. The players also performed the Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2). For the SE-players, blood samples were...... obtained and heart rate was measured before, during, and after the PT-test. A muscle biopsy was collected before and after the PT-test. Coefficient of variation for the PT- and CON-test was 11.7% and 16.0%, respectively. The YE-players performed better (P < 0.05) than the SE-players in both the PT-test (16...

  7. The use of single-specimen techniques for measuring upper shelf toughness properties under impact loading rates. Convention TRACTEBEL/SCK-CEN 2005 Task 1.1.5

    International Nuclear Information System (INIS)

    The multiple-specimen method (low-blow or stop-block tests) is the conventional approach for measuring the upper shelf fracture toughness of metallic materials under impact loading rates, typically fatigue precracked Charpy specimens tested on an instrumented pendulum machine. The method is fairly simple but requires a relatively large number of specimens. Nowadays, several single-specimen methods are available, which are purely based on the analysis of the instrumented force/displacement trace; they don't need any dedicated instrumentation for the measurement of crack extension during the test. Three of these techniques have been applied in this work to low-blow tests performed at different temperatures on two significantly different RPV steels (20MnMoNi55 and JSPS): the Normalization Data Reduction (NDR) technique, Schindler's Analytical 3-Parameter Approach and Chaouadi's method. Analyses have been performed after applying a double fitting approach to the raw test data, which allows selecting a limited set of force/displacement data which are representative of the whole instrumented trace. Results show that all three methods provide acceptable accuracy in terms of both ductile crack initiation and resistance to crack propagation (tearing modulus). However, for this type of analysis we recommend the use of the more widely accepted NDR technique, which is described in detail in the ASTM E1820-01 standard (although the limitations on data smoothness presently enforced in the standard seem incompatible with the oscillations of a typical dynamic PCCv curve). (author)

  8. Acoustic Emission Monitoring of Compression-after-Impact Test of Nano-Particles-Coated CFRP Damaged by Simulated Lightning Strikes

    International Nuclear Information System (INIS)

    Nanoparticles-coated and impact-damaged carbon-fiber reinforced plastics(CFRP) laminates were tested under compression-after-impact(CAI) mode and the propagation of damage due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. CFRP laminates were made of carbon prepregs prepared by coating of conductive nano-particles directly on the fibers and the coupons were subjected to simulated lightning strikes with a high voltage/current impulse of 10∼40 kA within a few microseconds. The effects of nano-particles coating and the degree of damage induced by the simulated lightning strikes on the AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terns of damage area by using ultrasonic C-scan images. From the results assessed during the CAI tests of damaged CFRP showed that AE monitoring appeared to be very useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes

  9. The increasing impact of socioeconomics and race on standardized academic test scores across elementary, middle, and high school.

    Science.gov (United States)

    White, Gwyne W; Stepney, Cesalie T; Hatchimonji, Danielle Ryan; Moceri, Dominic C; Linsky, Arielle V; Reyes-Portillo, Jazmin A; Elias, Maurice J

    2016-01-01

    For students and schools, the current policy is to measure success via standardized testing. Yet the immutable factors of socioeconomic status (SES) and race have, consistently, been implicated in fostering an achievement gap. The current study explores, at the school-level, the impact of these factors on test scores. Percentage of students proficient for Language and Math was analyzed from 452 schools across the state of New Jersey. By high school, 52% of the variance in Language and 59% in Math test scores can be accounted for by SES and racial factors. At this level, a 1% increase in school minority population corresponds to a 0.19 decrease in percent Language proficient and 0.33 decrease for Math. These results have significant implications as they suggest that school-level interventions to improve academic achievement scores will be stymied by socioeconomic and racial factors and efforts to improve the achievement gap via testing have largely measured it. PMID:26752444

  10. PROBLEMS IN TESTING DIGITAL PROTECTIVE RELAY FOR IMMUNITY TO INTENTIONAL DESTRUCTIVE ELECTROMAGNETIC IMPACTS. CONTINUATION OF THE THEME

    Directory of Open Access Journals (Sweden)

    Vladimir I. Gurevich

    2015-12-01

    Full Text Available The article is the continuation of the theme highlighted in the previous article with same title. The new article evaluates the results of digital protective relays (DPR testing for immunity to the E1 component of High-altitude Electromagnetic Pulse (HEMP and to Intentional Electromagnetic Interferences (IEMI impacts, conducted by some independent American organizations; discusses the features of relay protection devices as well as clarifies and supplements the procedure for testing these devices. Due to methodology errors during the DPR tests conducted by mentioned organizations earlier, they cannot be considered as satisfactory and their results as meaningful. At the moment there are no reliable data on the level of DPR immunity to IDEI, which suggests that the test should be conducted further.

  11. Impacts of test factors on heavy ion single event multiple-cell upsets in nanometer-scale SRAM

    International Nuclear Information System (INIS)

    Single event multiple-cell upsets (MCU) increase sharply with the semiconductor devices scaling. The impacts of several test factors on heavy ion single event MCU in 65 nm SRAM are studied based on the buildup of MCU test data acquiring and processing technique, including the heavy ion LET, the tilt angle, the device orientation, the test pattern and the supply voltage; the MCU physical bitmaps are extracted correspondingly. The dependencies of parameters such as the MCU percentage, MCU mean and topological pattern on these factors are summarized and analyzed. This work is meaningful for developing a more reasonable single event test method and assessing the effectiveness of anti-MCU strategies on nanometer-scale devices. (paper)

  12. Nuclear reactor pressure vessel integrity insurance by crack arrestability evaluation using load from CVN tests

    International Nuclear Information System (INIS)

    The present work is undertaken in the framework of nuclear reactor pressure vessel (RPV) surveillance and aims at revisiting the crack arrest approach to structural integrity insurance. This approach, performed under normal plant operation conditions, can also offer an attractive alternative to the crack initiation philosophy promoted for accidental analysis. To this end, an accidental conservative, cost effective and robust methodology is forwarded and demonstrated: it makes use of the crack arrest information contained in the instrumented Charpy V-notch impact test and/or in the shear fracture appearance of broken samples. Particular attention is paid to the appraisal of uncertainties and the related safety margin. The resulting capability is placed in perspective with the state-of-the-art crack initiation methodology based on the slow bend testing of recracked specimens, presently under standardization world-wide. The investigation leads to highlight three conceptual weaknesses of current enfgineering and regulatory practices. Improved crack arrestability evaluation emerges as an optimal approach to insure safe PWR operation up to design end-of-life and beyond

  13. Transient response of a beam on viscoelastic foundation under an impact load during nondestructive testing

    Institute of Scientific and Technical Information of China (English)

    Lu Sun; Feiquan Luo; Tung-Huei Chen

    2005-01-01

    Beam responses under an impact NDT load are studied using the Fourier and Laplace transforms. Numerical computation is performed for a parametric study of beam and load parameters. It is shown that under an impact load, the time duration for displacement to vanish is ten times longer than that for velocity and acceleration. The maximum response is achieved first in acceleration, followed by velocity, and finally displacement, all of which occur before the impact load is removed. At the moment that the impact load is removed from the beam, there is a discontinuity in the velocity and acceleration responses, but not in displacement response. The effect of K and ph on beam response is much less significant than that of EI and C, which have similar effect on beam response. As EI increases, peak values of displacement, velocity and acceleration response decrease. The effect of K on beam response only becomes appreciable after the impact load is removed.While the peak of displacement remain almost unchanged as K increases, the displacement response decays to zero faster for large K values than for small K values.

  14. The impact of national standards assessment in New Zealand, and national testing protocols in Norway on indigenous schooling

    Directory of Open Access Journals (Sweden)

    Kamil ÖZERK

    2012-01-01

    Full Text Available This paper first provides a critic of the implementation of compulsory national assessment protocols internationally, and then nationally through a review of the implementation process used for the introduction of National Standards in New Zealand, and National Testing in Norwegian mainstream schools. It then reviews the impact of these two assessment regimes on indigenous Mãori and Sámi -medium schools in the context of historic policies of marginalisation and assimilation. Finally, it notes the crucial role of each national government in securing funding for the production of culturally responsive National Standards and National Testing in the effort of both indigenous groups to protect their languages and cultures.

  15. Framework for Testing the Effectiveness of Bat and Eagle Impact-Reduction Strategies at Wind Energy Projects

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, Karin [National Renewable Energy Lab. (NREL), Golden, CO (United States); DeGeorge, Elise [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-04-13

    The objectives of this framework are to facilitate the study design and execution to test the effectiveness of bat and eagle impact-reduction strategies at wind energy sites. Through scientific field research, the wind industry and its partners can help determine if certain strategies are ready for operational deployment or require further development. This framework should be considered a living document to be improved upon as fatality-reduction technologies advance from the initial concepts to proven readiness (through project- and technology-specific testing) and as scientific field methods improve.

  16. DEVELOPMENT OF A SOIL ABRASION TESTS AND ANALYSIS OF IMPACT OF SOILCONDITIONING OM TOOL WEAR FOR SOFTGROUND MECHANIZAED TUNNELING

    OpenAIRE

    2016-01-01

    The wear issue in soft-ground tunneling using various types of shields has a major impact on machine operation, utilization, and tunneling costs. The interaction between abrasive soils and cutters, as well as other components of the machine that are involved in excavation process can cause the wear. For tool wear estimation and understanding of soil conditioning effect on wear, there is no accepted test that can address this issue clearly. The primary objective of this thesis was to develop a...

  17. Cognitive Personality Characteristics Impact the Course of Depression: A Prospective Test of Sociotropy, Autonomy and Domain-Specific Life Events

    OpenAIRE

    Iacoviello, Brian M.; Grant, David A.; Alloy, Lauren B.; Abramson, Lyn Y.

    2009-01-01

    Prospective tests of the impact of sociotropy and autonomy on the course of depression are lacking. In a sample of 97 cognitive high-risk and 62 cognitive low-risk undergraduates who experienced at least one prospective depressive episode, the interactions of sociotropy and interpersonal life events and autonomy and achievement-related life events were examined as predictors of four indicators of the course of depression. Initial analyses failed to support the hypothesis that global scores fo...

  18. The impact of national standards assessment in New Zealand, and national testing protocols in Norway on indigenous schooling

    OpenAIRE

    Kamil ÖZERK; Whitehead, David

    2012-01-01

    This paper first provides a critic of the implementation of compulsory national assessment protocols internationally, and then nationally through a review of the implementation process used for the introduction of National Standards in New Zealand, and National Testing in Norwegian mainstream schools. It then reviews the impact of these two assessment regimes on indigenous Mãori and Sámi -medium schools in the context of historic policies of marginalisation and assimilation. Finally, it notes...

  19. The impact of risk information exposure on women's beliefs about direct-to-consumer genetic testing for BRCA mutations.

    Science.gov (United States)

    Gray, S W; Hornik, R C; Schwartz, J S; Armstrong, K

    2012-01-01

    Despite an increase in direct-to-consumer (DTC) genetic testing, little is known about how variations in website content might alter consumer behavior. We evaluated the impact of risk information provision on women's attitudes about DTC BRCA testing. We conducted a randomized experiment; women viewed a 'mock' BRCA testing website without [control group (CG)] or with information on the potential risks of DTC testing [RG; framed two ways: unattributed risk (UR) information and risk information presented by experts (ER)]. Seven hundred and sixty-seven women participated; mean age was 37 years, mean education was 15 years, and 79% of subjects were white. Women in the RG had less positive beliefs about DTC testing (mean RG = 23.8, CG = 25.2; p = 0.001), lower intentions to get tested (RG = 2.8, CG = 3.1; p = 0.03), were more likely to prefer clinic-based testing (RG = 5.1, CG = 4.8; p = 0.03) and to report that they had seen enough risk information (RG = 5.3, CG = 4.7; p risks of DTC BRCA testing altered their beliefs, preferences, and intentions. Risk messages appear to be salient to women irrespective of their chance of having a BRCA mutation. PMID:21992449

  20. Impact of a confirmatory RhD test on the correct serologic typing of blood donors

    Directory of Open Access Journals (Sweden)

    Luciana Cayres Schmidt

    2015-10-01

    Full Text Available BACKGROUND: The RHD gene is highly polymorphic, which results in a large number of RhD variant phenotypes. Discrepancies in RhD typing are still a problem in blood banks and increase the risk of alloimmunization. In this study, the RhD typing strategy at a blood bank in Brazil was evaluated.METHODS: One-hundred and fifty-two samples typed as RhD negative and C or E positive by routine tests (automated system and indirect antiglobulin test using the tube technique were reevaluated for RhD status by three methods. The method with the best performance was implemented and evaluated for a period of one year (n = 4897 samples. Samples that were D positive exclusively in the confirmatory test were submitted to molecular analysis.RESULTS: The gel test for indirect antiglobulin testing with anti-D immunoglobulin G (clone ESD1 presented the best results. Seventy samples (1.43% previously typed as RhD negative showed reactivity in the gel test for indirect antiglobulin testing and were reclassified as D positive. D variants that may cause alloimmunization, such as weak D type 2 and partial DVI, were detected.CONCLUSION: The confirmatory RhD test using the gel test for indirect antiglobulin testing represents a breakthrough in transfusion safety in this blood center. Our results emphasize the importance of assessing the blood group typing strategy in blood banks.

  1. IMPACTS !

    CERN Multimedia

    2008-01-01

    (Photo courtesy of Don Davis / NASA)The University of Geneva (UNIGE) and the Ecole Polytechnique Fédérale of Lausanne (EPFL) are organising the 4th series of public lectures on astronomy, on the theme of "Impacts". The schedule is as follows: Il y a 100 ans : une explosion dans la Tunguska – Dr. Frédéric COURBIN, EPFL Les impacts sur Terre – Prof. Didier Queloz, UNIGE La fin des dinosaures – Dr. Stéphane Paltani, UNIGE Wednesday 7 May 2008, from 7.00 p.m. to 9.00 p.m. Auditoire CO1, EPFL, Ecublens Thursday 08 May 2008, from 7.00 p.m. to 9.00 p.m. Auditoire Rouiller, Uni-Dufour, Genève All 3 lectures will be givent each evening! Admission free Information: 022 379 22 00

  2. Application of nondestructive testing methods to study the damage zone underneath impact craters of MEMIN laboratory experiments

    Science.gov (United States)

    Moser, Dorothee; Poelchau, Michael H.; Stark, Florian; Grosse, Christian

    2013-01-01

    Within the framework of the Multidisciplinary Experimental and Modeling Impact Research Network (MEMIN) research group, the damage zones underneath two experimentally produced impact craters in sandstone targets were investigated using several nondestructive testing (NDT) methods. The 20 × 20 × 20 cm sandstones were impacted by steel projectiles with a radius of 1.25 mm at approximately 5 km s-1, resulting in craters with approximately 6 cm diameter and approximately 1 cm depth. Ultrasound (US) tomography and vibrational analysis were applied before and after the impact experiments to characterize the damage zone, and micro-computer tomography (μ-CT) measurements were performed to visualize subsurface fractures. The newly obtained experimental data can help to quantify the extent of the damage zone, which extends to about 8 cm depth in the target. The impacted sandstone shows a local p-wave reduction of 18% below the crater floor, and a general reduction in elastic moduli by between approximately 9 and approximately 18%, depending on the type of elastic modulus. The results contribute to a better empirical and theoretical understanding of hypervelocity events and simulations of cratering processes.

  3. Materials, Manufacturing, and Test Development of a Composite Fan Blade Leading Edge Subcomponent for Improved Impact Resistance

    Science.gov (United States)

    Miller, Sandi G.; Handschuh, Katherine; Sinnott, Matthew J.; Kohlman, Lee W.; Roberts, Gary D.; Martin, Richard E.; Ruggeri, Charles R.; Pereira, J. Michael

    2015-01-01

    Application of polymer matrix composite materials for jet engine fan blades is becoming attractive as an alternative to metallic blades; particularly for large engines where significant weight savings are recognized on moving to a composite structure. However, the weight benefit of the composite is offset by a reduction of aerodynamic efficiency resulting from a necessary increase in blade thickness; relative to the titanium blades. Blade dimensions are largely driven by resistance to damage on bird strike. Further development of the composite material is necessary to allow composite blade designs to approximate the dimensions of a metallic fan blade. The reduction in thickness over the state of the art composite blades is expected to translate into structural weight reduction, improved aerodynamic efficiency, and therefore reduced fuel consumption. This paper presents test article design, subcomponent blade leading edge fabrication, test method development, and initial results from ballistic impact of a gelatin projectile on the leading edge of composite fan blades. The simplified test article geometry was developed to realistically simulate a blade leading edge while decreasing fabrication complexity. Impact data is presented on baseline composite blades and toughened blades; where a considerable improvement to impact resistance was recorded.

  4. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  5. Determine an effective golf swing by swing speed and impact precision tests

    Directory of Open Access Journals (Sweden)

    Jiann-Jyh Wang

    2015-09-01

    Conclusion: The vertical peak ground reaction force on left foot occurring before impact and the left latissimus dorsi contracting prior to the right pectoralis major represent a superior skill by allowing the club to strike the ball with normal collision at a faster speed.

  6. Development for advanced materials and testing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hishinuma, Akimichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Recent studies using a JMTR and research reactors of JRR-2 and JRR-3 are briefly summarized. Small specimen testing techniques (SSTT) required for an effective use of irradiation volume and also irradiated specimens have been developed focussing on tensile test, fatigue test, Charpy test and small punch test. By using the small specimens of 0.1 - several mm in size, similar values of tensile and fatigue properties to those by standard size specimens can be taken, although the ductile-brittle transition temperature (DBTT) depends strongly on Charpy specimen size. As for advanced material development, R and D about low activation ferritic steels have been done to investigate irradiation response. The low activation ferritic steel, so-called F82H jointly-developed by JAERI and NKK for fusion, has been confirmed to have good irradiation resistance within a limited dose and now selected as a standard material in the fusion material community. It is also found that TiAi intermetallic compounds, which never been considered for nuclear application in the past, have an excellent irradiation resistance under an irradiation condition. Such knowledge can bring about a large expectation for developing advanced nuclear materials. (author)

  7. The Impact of the Use of Hierarchical Teaching on Test Scores of Students’ Technology

    OpenAIRE

    Zhao Guorong; Yang Meng

    2015-01-01

    Test scores of students’ technology is the main basis for physical examination of college students’ physical, fitness evaluation based on test results. To change the view by the stratified teaching method consistent system of teaching mode, special movement technical level of students is improved significantly.

  8. What factors impact upon a woman’s decision to undertake genetic cancer testing?

    Directory of Open Access Journals (Sweden)

    JulieAnneQuinlivan

    2014-01-01

    Full Text Available Introduction: The advent of human genome project has lead to genetic tests that identify high-risk states for certain cancers. Many are privately marketed on the Internet. Despite the availability of tests, limited data has evaluated factors that lead to test uptake. The aim of the present study was to explore the attitudes of a cohort of new mothers towards uptake of a genetic cancer test with a 50% predictive value of cancer.Methods: A cross-sectional survey was undertaken. The project targeted women who had recently given birth at an Australian tertiary referral hospital. Women were asked about a theoretical blood test that detected an increased risk for the development of cancer. Attitudes and knowledge questionnaires were completed. Results: Of 232 consecutive women approached, 32 declined, giving a response rate of 86.2%. Only 63 (31.5% women stated they would have the test. Absence of religious belief, higher level of education, better knowledge of terms used in genetics, an absence of concern over emotional, employment and insurance discrimination and previous acceptance of Down syndrome screening in pregnancy were each associated with significantly higher rate of test uptake in univariate analysis (all pConclusion: Concern over discrimination and having made a prior decision to have genetic testing were the principal factors associated with decision-making.

  9. The impact of educational level on performance on auditory processing tests

    Directory of Open Access Journals (Sweden)

    Cristina F.B. Murphy

    2016-03-01

    Full Text Available Research has demonstrated that a higher level of education is associated with better performance on cognitive tests among middle-aged and elderly people. However, the effects of education on auditory processing skills have not yet been evaluated. Previous demonstrations of sensory-cognitive interactions in the aging process indicate the potential importance of this topic. Therefore, the primary purpose of this study was to investigate the performance of middle-aged and elderly people with different levels of formal education on auditory processing tests. A total of 177 adults with no evidence of cognitive, psychological or neurological conditions took part in the research. The participants completed a series of auditory assessments, including dichotic digit, frequency pattern and speech-in-noise tests. A working memory test was also performed to investigate the extent to which auditory processing and cognitive performance were associated. The results demonstrated positive but weak correlations between years of schooling and performance on all of the tests applied. The factor years of schooling was also one of the best predictors of frequency pattern and speech-in-noise test performance. Additionally, performance on the working memory, frequency pattern and dichotic digit tests was also correlated, suggesting that the influence of educational level on auditory processing performance might be associated with the cognitive demand of the auditory processing tests rather than auditory sensory aspects itself. Longitudinal research is required to investigate the causal relationship between educational level and auditory processing skills.

  10. Reducing the Impact of Inappropriate Items on Reviewable Computerized Adaptive Testing

    Science.gov (United States)

    Yen, Yung-Chin; Ho, Rong-Guey; Liao, Wen-Wei; Chen, Li-Ju

    2012-01-01

    In a test, the testing score would be closer to examinee's actual ability when careless mistakes were corrected. In CAT, however, changing the answer of one item in CAT might cause the following items no longer appropriate for estimating the examinee's ability. These inappropriate items in a reviewable CAT might in turn introduce bias in ability…

  11. Effect of heat treatment and cleanness of ultra low carbon bainitic (ULCB) steel on its impact toughness

    International Nuclear Information System (INIS)

    The small variations in sulphur and carbon concentrations can have a major influence on the impact transition temperature (ITT) of ultra low carbon HSLA-100 steel which has been quenched in water and tempered (WQ and T). Since the average carbon concentration is very low thus sensitivity of ITT to heat treatment parameters depends also on the yield strength increase due to precipitation effect of εCu phase. The regression analysis has been used to establish equations taking into account those parameters. The properties of a mixed microstructure formed from partially austenitic regions have been also considered. The fine austenitic grains transform into more desirable fine bainitic ferrite phases with lower hardness values and higher toughness. On the other hand, if cooling rate is sufficiently large, then the carbon enriched austenite transforms partially into hard martensite and some of remaining untransformed austenite being retained to ambient temperature. Because hard martensite islands are located in much softer surroundings consisting of tempered ferrite, they do not cause a general reduction in impact toughness tests. Due to further grain refinement of microstructure the measured toughness on Charpy V specimens can be very high at low temperatures. The very detrimental effect of sulphur in ULCB steel has been confirmed by presented results. (author)

  12. Final environmental impact statement for the Nevada Test Site and off-site locations in the State of Nevada. Summary

    International Nuclear Information System (INIS)

    This sitewide EIS evaluates the potential environmental impacts of four possible land-use alternatives being considered for the Nevada Test Site (NTS), the Tonopah Test Range, and the formerly operated DOE sites in the state of Nevada: the Project Shoal Area, the Central Nevada Test Area, and portions of the Nellis Air Force Range Complex. Three additional sites in Nevada-Eldorado Valley, Dry Lake Valley, and Coyote Spring Valley-are evaluated for collocation of solar energy production facilities. The four alternatives include Continue Current Operations (No Action, continue to operate at the level maintained for the past 3 to 5 years); Discontinue Operations 1 (discontinue operations and interagency programs); Expanded Use (increased use of NTS and its resources to support defense and nondefense programs); and Alternate Use of Withdrawn Lands (discontinue all defense-related activities at NTS; continue waste management operations in support of NTS environmental restoration efforts; expand nondefense research). Environmental impacts were assessed for each alternative by analyzing, to the extent possible, the discrete and cumulative environmental impacts associated with Defense Waste Management, Environmental Restoration, Nondefense Research and Development, and Work for Others Programs. A framework for a Resource Management Plan is included as Volume 2 of this EIS and represents the development of an ecosystem based planning process closely integrated with the National Environmental Policy Act process. This EIS, among other things, analyzed the impacts of transportation of low level waste, and site characterization activities related to the Yucca Mountain Project but did not analyze the suitability of the site as a repository. This EIS does not analyze the suitability of the Yucca Mountain site as a repository as this is an action beyond the scope of the EIS. Volume 3 of this EIS contains the public comments and the responses to the comments

  13. CO2 Employment as Refrigerant Fluid with a Low Environmental Impact. Experimental Tests on Arugula and Design Criteria for a Test Bench

    Directory of Open Access Journals (Sweden)

    Biagio Bianchi

    2015-03-01

    Full Text Available In order to define design criteria for CO2 refrigeration systems to be used for agricultural products and foodstuff storage, a variable geometrical system was realized, with the goal of meeting a wide range of environmental and process conditions, such as producing low environmental impact and maintaining the highest Coefficient of Performance (COP, at the same time. This test-bench, at semi-industrial scale, was designed as a result of experimental tests carried out on Arugula. The storage tests showed that all samples stored in cold rooms with R.H. control showed a slight increase of weight but also small rot zones in all the boxes due to an excessive accumulation of water condensation; thus, the system may not have achieved conditions that RH requires in a given range, without reaching saturation condition. At the same time, the use of CO2 must be adequately tested along its thermodynamic cycle, during steady state and/or transient conditions, imposing variable working conditions that can simulate plant starting phase or some striking conservation process, like those that characterize sausages. The designed plant will allow studying these specific performances and evaluate COP variation, according to environmental and plant operating conditions.

  14. Elevated Temperature Ballistic Impact Testing of PBO and Kevlar Fabrics for Application in Supersonic Jet Engine Fan Containment Systems

    Science.gov (United States)

    Pereira, J. Michael; Roberts Gary D.; Revilock, Duane M., Jr.

    1997-01-01

    Ballistic impact tests were conducted on fabric made from both Poly(phenylene benzobizoxazole) (PBO) and Kevlar 29 which were selected to be similar in weave pattern, areal density, and fiber denier. The projectiles were 2.54-cm- (1-in.-) long aluminum cylinders with a diameter of 1.27 cm (0.5 in.). The fabric specimens were clamped on four sides in a 30.5-cm- (12-in.-) square frame. Tests on PBO were conducted at room temperature and at 260 C (500 F). A number of PBO specimens were aged in air at 204 and 260 C (400 and 500 F) before impact testing. Kevlar specimens were tested only at room temperature and with no aging. The PBO absorbed significantly more energy than the Kevlar at both room and elevated temperatures. However, after aging at temperatures of 204 C (400 F) and above, the PBO fabric lost almost all of its energy absorbing ability. It was concluded that PBO fabric is not a feasible candidate for fan containment system applications in supersonic jet engines where operating temperatures exceed this level.

  15. Regression Test of Independence of the Impact of Petroleum Industry on the Agricultural Sector in Nigeria (1972-2009

    Directory of Open Access Journals (Sweden)

    Sule Ja’afaru Garba

    2013-02-01

    Full Text Available This paper titled “the impact of petroleum sector on the agricultural development in Nigeria between 1972-2009’ is a child of necessity. The negative impact of over relying on the petroleum sector thereby neglecting the Agricultural sector is seen here as the major problem that borders the mind of the researcher. The primary objective here is to analyze critical the implication of over reliance on petroleum sector as the only major source of foreign exchange for the country and as such try to suggest some possible ways out as one can never he sure of what will be the faith of the Nigeria economy tomorrow should the going get tough. The researcher used secondary method to obtain his data. It was discovered that reverse will be for the Nigeria economy tomorrow in case of economic meltdown due to over reliance on the oil sector. Simple regression model was used to test the degree of relationship between the dependent and the independent variable. Meanwhile, the researcher employed the coefficient of determination to test the goodness of fit, while f-test was employed to test the significance of the regression estimated and a priority and magnitude of the regression co-efficient evaluated. It has been recommended that revenue derived from petroleum export be expended on projects that will bring about meaningful transformation in the agricultural sector.

  16. The Impact of Integration of Rapid Syphilis Testing during Routine Antenatal Services in Rural Kenya

    Directory of Open Access Journals (Sweden)

    Eleanor Fleming

    2013-01-01

    Full Text Available We evaluated the integration of rapid syphilis tests (RSTs and penicillin treatment kits into routine antenatal clinic (ANC services in two rural districts in Nyanza Province, Kenya. In February 2011, nurses from 25 clinics were trained in using RSTs and documenting test results and treatment. During March 2011–February 2012, free RSTs and treatment kits were provided to clinics for use during ANC visits. We analyzed ANC registry data from eight clinics during the 12-month periods before and during RST program implementation and compared syphilis testing, diagnosis, and treatment during the two periods. Syphilis testing at first ANC visit increased from 18% (279 of 1,586 attendees before the intervention to 70% (1,123 of 1,614 attendees during the intervention (P<0.001; 35 women (3% tested positive during the intervention period compared with 1 (<1% before (P<0.001. Syphilis treatment was not recorded according to training recommendations; seven clinics identified 28 RST-positive women and recorded 34 treatment kits as used. Individual-level data from three high-volume clinics supported that the intervention did not negatively affect HIV test uptake. Integrating RSTs into rural ANC services increased syphilis testing and detection. Record keeping on treatment of syphilis in RST-positive women remains challenging.

  17. Intervening to decrease the probability of alcohol-impaired driving: Impact of novel field sobriety tests.

    Science.gov (United States)

    Smith, Ryan C; Robinson, Zechariah; Bazdar, Alexandra; Geller, E Scott

    2016-01-01

    The efficacy of novel field sobriety tests to predict breath alcohol content (BAC) and perceptions of driving risk was evaluated. Participants (N = 210) were passersby at two downtown locations near local bars and one on-campus location near a late-night dining facility between the hours of 10:00 p.m. and 2:00 a.m. Participants gave ratings of their perceived risk to drive at their current level of intoxication, then completed three sobriety tests (a hand-pat, tracing test, and Romberg test), and finally provided new ratings of their perceived risk to drive. After completing the final set of questions, participants were administered a Lifeloc FC20 breath alcohol test (±.005 g/dL). Each of the sobriety tests performed better than chance at predicting participant intoxication, but the performance feedback did not enhance awareness of one's risk to drive at a given BAC. Actually, after the sobriety tests, Greek-life females perceived themselves to be less at-risk to drive. PMID:27309028

  18. Heat treatment effects on impact toughness of 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated to 100 dpa

    International Nuclear Information System (INIS)

    Plates of 9Cr-1MoVNb and 12Cr-1MoVW steels were given four different heat treatments: two normalizing treatments were used and for each normalizing treatment two tempers were used. Miniature Charpy specimens from each heat treatment were irradiated to ∼19.5 dpa at 365 degrees C and to ∼100 dpa at 420 degrees C in the Fast Flux Test Facility (FFTF). In previous work, the same materials were irradiated to 4-5 dpa at 365 degrees C and 35-36 dpa at 420 degrees C in FFTF. The tests indicated that prior austenite grain size, which was varied by the different normalizing treatments, had a significant effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. Conclusions are presented on how heat treatment can be used to optimize impact properties

  19. Heat treatment effects on impact toughness of 9Cr-1MoVNb and 12Cr-1MoVW steels irradiated to 100 dpa

    Energy Technology Data Exchange (ETDEWEB)

    Klueh, R.L.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

    1997-08-01

    Plates of 9Cr-1MoVNb and 12Cr-1MoVW steels were given four different heat treatments: two normalizing treatments were used and for each normalizing treatment two tempers were used. Miniature Charpy specimens from each heat treatment were irradiated to {approx}19.5 dpa at 365{degrees}C and to {approx}100 dpa at 420{degrees}C in the Fast Flux Test Facility (FFTF). In previous work, the same materials were irradiated to 4-5 dpa at 365{degrees}C and 35-36 dpa at 420{degrees}C in FFTF. The tests indicated that prior austenite grain size, which was varied by the different normalizing treatments, had a significant effect on impact behavior of the 9Cr-1MoVNb but not on the 12Cr-1MoVW. Tempering treatment had relatively little effect on the shift in DBTT for both steels. Conclusions are presented on how heat treatment can be used to optimize impact properties.

  20. Addressing the Regression Test Problem with Change Impact Analysis for Ada

    OpenAIRE

    Jones, Andrew V.

    2016-01-01

    The regression test selection problem--selecting a subset of a test-suite given a change--has been studied widely over the past two decades. However, the problem has seen little attention when constrained to high-criticality developments and where a "safe" selection of tests need to be chosen. Further, no practical approaches have been presented for the programming language Ada. In this paper, we introduce an approach to solving the selection problem given a combination of both static and dyn...