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Sample records for charpy impact test

  1. 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.

  2. Quality assurance of absorbed energy in Charpy impact test

    Science.gov (United States)

    Rocha, C. L. F.; Fabricio, D. A. K.; Costa, V. M.; Reguly, A.

    2016-07-01

    In order to ensure the quality assurance and comply with standard requirements, an intralaboratory study has been performed for impact Charpy tests, involving two operators. The results based on ANOVA (Analysis of Variance) and Normalized Error statistical techniques pointed out that the execution of the tests is appropriate, because the implementation of quality assurance methods showed acceptable results.

  3. 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

  4. Instrumented charpy impact tests of austenitic and ferritic steels

    Science.gov (United States)

    Yoshida, H.; Miyata, K.; Hayashi, Y.; Narui, M.; Kayano, H.

    1985-08-01

    The instrumented Charpy impact test was applied to commercial Mn-steel and ferritic steels before and after JMTR irradiation ( 6.5 × 10 22 n/m 2). The load-deflection curves show typical characteristics of the fracture properties of the specimens; i.e. linear elastic behaviour for the brittle fracture and elastic-plastic behaviour for the ductile fracture. The fracture deflection and the absorption energy (fracture energy) dropped rapidly at the temperature of ductile to brittle transition. The ductile-brittle transition temperatures (DBTTs) showed shifts of about 30 and 40 K due to the irradiation for 9Cr-1Mo and 9Cr-2Mo steels, respectively. In Mn-steel the transition from ductile to brittle did not appear at temperatures higher than 77 K. The lateral expansions measured from the scanning electron micrographs show good correspondence to the above results.

  5. Comparison of Impact Duration Between Experiment and Theory From Charpy Impact Test

    Directory of Open Access Journals (Sweden)

    Muhammad Said N.B.

    2016-01-01

    Full Text Available This study presents the comparison of impact duration between experiment and theory from impact signal through a Charpy test. Recently, the number of accidents on the highway has been increased and it depends on the impact duration of material that have the ability to provide adequate protection to passengers from harmful and improve occupant survivability during crash event. Charpy impact test was implemented on different material and thickness but at the same striker velocity. Impact signal is obtained through the strain gauge that has been installed to striker hammer and connected to frequency data acquisition system. Collected signal is then analysed to identify the time period during impact before fractured. Result from both experiment and theory shows an increment to the impact duration as thickness is increased. Charpy test shows that aluminium 6061-T6 has a higher impact duration compared to carbon steel 1050.

  6. Fracture behaviors of neutron-irradiated ferritic steels studied by the instrumented charpy impact test

    Science.gov (United States)

    Yoshida, H.; Miyata, K.; Narui, M.; Kayano, H.

    1989-12-01

    The instrumented Charpy impact test for quarter-size specimens was developed and applied to study fracture behavior of ferritic steels and a ferritic-martensitic steel (JFMS) before and after neutron irradiation. The load-deflection curves obtained for U- and V-notched specimens showed typical characteristics of fracture properties of these steels. The temperature dependence of the fracture energy ( Ef) and the failure deflection ( Df) clearly indicates ductile-brittle transition and the DBTT can be determined from the Ef and Df versus temperature curves. The V-notched specimens showed sharper transition at higher temperatures for the JFMS than the U-notched ones, where the former were sensitive to brittle fracture and the latter well demonstrated the behavior of crack propagation. For the ferritic steels the DBTTs showed low values at compositions containing approximate 8-10% Cr and the increase of the DBTT (Δ DBTT) due to irradiation also showed a similar tendency. The Δ DBTT appeared to be relatively larger for the JFMS than the ferritic steels.

  7. Reconstituted Charpy impact specimens. Final report

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    Perrin, J.S.; Wullaert, R.A.; McConnell, P.; Server, W.L.; Fromm, E.O.

    1982-12-01

    The arc stud welding process was used to produce new, full size Charpy V-notch impact specimens from halves of Charpy specimens which had been previously tested. The apparatus was developed such that it could be used not only for unirradiated specimens, but also so that it could be adapted for in-cell use to produce new reconstituted specimens of irradiated material. The materials studied are of interest in nuclear applications. They include A533B, A36, A516-80, submerged arc weld metal (A508 base metal), HY80, cast duplex stainless steel, irradiated A533B, and irradiated submerged arc weld metal (A508 base metal). Both unirradiated and irradiated specimens were successfully produced and subsequently impact tested. In general, there was excellent agreement when comparing the original curves to the subsequent curves generated with reconstituted specimens. This program has shown that the arc stud welding process is well suited for producing reconstituted specimens at a reasonable cost using either unirradiated or irradiated material.

  8. Experimental study on the material dynamic fracture properties by Instrumented Charpy Impact test with single specimen method

    Science.gov (United States)

    Jian, F.; Fulian, D.; Chengzhong, W.

    2003-09-01

    With the determination of load-time curve recorded by Amsler/Roell RKP 450 Instrumented Charpy Impact test and based on the Newton's Second Law, Impact character of a single standard V-notch specimen of X70 pipeline steel under the low temperature -70 ^{circ}C was investigated by studying the impact energy distribution. It was revealed that maximum load point (Fm point) was not exact the dynamic crack initiation, which was detected somewhere prior and very close to Fm point by using Compliance Changing Rate method. This fact was also confirmed by Dynamic CTOD method. That is to say, Impact energy related to the Fm point (i.e. Em) consists not only the crack initiation energy Ei, but a small part of crack extension energy as well. Ratio of Ei/Em was found to be 0.90 just applicable to the material used here. Dynamic fracture toughness JJd was then estimated by modified Rice equation. Crack extension behavior and dynamic crack growth resistance curve (J-Δa) during stable crack propagation period was carefully analyzed by Key Curve method. Finally, methods for evaluating tearing module Tmat, and CTOD curve under the impact test were also briefly introduced in the paper.

  9. Correlation between standard Charpy and sub-size Charpy test results of selected steels in upper shelf region

    Science.gov (United States)

    Konopík, P.; Džugan, J.; Bucki, T.; Rzepa, S.; Rund, M.; Procházka, R.

    2017-02-01

    Absorbed energy obtained from impact Charpy tests is one of the most important values in many applications, for example in residual lifetime assessment of components in service. Minimal absorbed energy is often the value crucial for extending components service life, e.g. turbines, boilers and steam lines. Using a portable electric discharge sampling equipment (EDSE), it is possible to sample experimental material non-destructively and subsequently produce mini-Charpy specimens. This paper presents a new approach in correlation from sub-size to standard Charpy test results.

  10. 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.

  11. Charpy impact test of Ti-6Al-4V joints diffusion welded at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, J.M.G. de; Urena, A. [Complutense Univ. of Madrid (Spain); Carrion, J.G. [National Inst. of Aeroespatial Technologies, Madrid (Spain). Materials and Structures Div.

    1996-08-15

    The Diffusion Welding (DW) of two or more sheets of Ti-6Al-4V alloy is particularly interesting for aerospace parts manufacturing. In some cases, DW can be carried out together with Superplastic Forming (SPF), because they can share a single facility and the same processing parameters, such as temperature, pressure, time, surface condition and vacuum. The overall manufacturing process is known as SPF/DW, by which it is possible to obtain honeycomb structures in a range of designs. Temperature requirements for industrial SPF of Ti-6Al-4V are very restrictive and a temperature of 1,023 K is needed. However, temperature is not so critical for DW, and the bond can be produced at lower temperatures, when other DW parameters, mainly pressure and time, are changed in a suitable way. The DW parameters for this research were chosen in order to produce DW joints below 1,023 K. The differences between DW at SPF temperatures and other lower temperatures would thus be revealed. Mechanical tests were used as a tool to check DW joints obtained at the temperatures used in the research (1,123 K and 1,023 K), and were complemented with metallographic studies. The results obtained form shear and peel tests have been already discussed. In the present work the results of impact energy tests are also presented.

  12. Charpy Impact Energy and Microindentation Hardness of 60-NITINOL

    Science.gov (United States)

    Stanford, Malcolm K.

    2012-01-01

    60-NITINOL (60 wt.% Ni 40 wt.% Ti) is being studied as a material for advanced aerospace components. The Charpy impact energy and microindentation hardness has been studied for this material, fabricated by vacuum induction skull melting (casting) and by hot isostatic pressing. Test specimens were prepared in various hardened and annealed heat treatment conditions. The average impact energy ranged from 0.33 to 0.49J for the hardened specimens while the annealed specimens had impact energies ranging from 0.89 to 1.18J. The average hardness values of the hardened specimens ranged from 590 to 676 HV while that of the annealed specimens ranged from 298 to 366 HV, suggesting an inverse relationship between impact energy and hardness. These results are expected to provide guidance in the selection of heat treatment processes for the design of mechanical components.

  13. 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.

  14. Dynamic fracture toughness and Charpy impact properties of an AISI 403 martensitic stainless steel

    Science.gov (United States)

    Sreenivasan, P. R.; Ray, S. K.; Mannan, S. L.; Rodriguez, P.

    1996-04-01

    Dynamic fracture toughness and Charpy impact properties of a normalised and tempered AISI 403 martensitic stainless steel obtained from instrumented impact tests are presented. Procedures for estimating dynamic fracture toughness ( KId) from the load-time traces obtained in instrumented tests of unprecracked Charpy V-notch (CVN) specimens are considered. The estimated KId values show reasonable agreement with those obtained from instrumented drop-weight and precracked Charpy tests. Also, except in the upper transition and uppershelf regions, the ASME KIR curve is generally conservative (i.e. gives lower KId values) when compared to the above KId estimates. The conservatism of the ASME KIR at the upper transition and uppershelf temperatures needs verification/validation. The lowest KId values estimated at the lower shelf temperatures for the above steel, namely, 33-42 MPa√m are in good agreement with the reported values of 35-50 MPa√m for the same steel in the literature.

  15. Further Charpy impact test results of low activation ferritic alloys, irradiated at 430{degrees}C to 67 dpa

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

    Miniature CVN specimens of four ferritic alloys, GA3X, F82H, GA4X and HT9, have been impact tested following irradiation at 430{degrees}C to 67 dpa. Comparison of the results with those of the previously tested lower dose irradiation condition indicates that the GA3X and F82H alloys, two primary candidate low activation alloys, exhibit virtually identical behavior following irradiation at 430{degrees}C to {approximately}67 dpa and at 370{degrees}C to {approximately}15 dpa. Very little shift is observed in either DBTT or USE relative to the unirradiated condition. The shifts in DBTT and USE observed in both GA4X and HT9 were smaller after irradiation at 430{degrees}C to {approximately}67 dpa than after irradiation at 370{degrees}C to {approximately}15 dpa.

  16. 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.

  17. Miniaturized Charpy test for reactor pressure vessel embrittlement characterization

    Energy Technology Data Exchange (ETDEWEB)

    Manahan, M.P. Sr. [MPM Research and Consulting, Lemont, PA (United States)

    1999-10-01

    Modifications were made to a conventional Charpy machine to accommodate the miniaturized Charpy V-Notch (MCVN) specimens which were fabricated from an archived reactor pressure vessel (RPV) steel. Over 100 dynamic MCVN tests were performed and compared to the results from conventional Charpy V-Notch (CVN) tests to demonstrate the efficacy of the miniature specimen test. The optimized sidegrooved MCVN specimens exhibit transitional fracture behavior over essentially the same temperature range as the CVN specimens which indicates that the stress fields in the MCVN specimens reasonably simulate those of the CVN specimens and this fact has been observed in finite element calculations. This result demonstrates a significant breakthrough since it is now possible to measure the ductile-brittle transition temperature (DBTT) using miniature specimens with only small correction factors, and for some materials as in the present study, without the need for any correction factor at all. This development simplifies data interpretation and will facilitate future regulatory acceptance. The non-sidegrooved specimens yield energy-temperature data which is significantly shifted downward in temperature (non-conservative) as a result of the loss of constraint which accompanies size reduction.

  18. Certification of Charpy V-notch Reference Test Pieces of 80 J Nominal Absorbed Energy (ERM®-FA015x and ERM®-FA015y)

    OpenAIRE

    LAMBERTY MARIE ANDREE; Dean, Alan; Roebben, Gert

    2011-01-01

    This certification report describes the processing and characterisation of ERM®-FA015x and ERM®-FA015y, two batches of Charpy V-notch certified reference test pieces. Sets of five of these test pieces are used for the verification of pendulum impact test machines according to EN 10045-2 (Charpy impact test on metallic materials, Part 2. Method for the verification of impact testing machines) or according to ISO 148-2 (Metallic materials - Charpy pendulum impact test – Part 2: Verification of ...

  19. Effect of grain structure on Charpy impact behavior of copper

    Science.gov (United States)

    Liang, Ningning; Zhao, Yonghao; Wang, Jingtao; Zhu, Yuntian

    2017-01-01

    Nanostructured (NS) and ultrafine-grained (UFG) materials have high strength and relatively low ductility. Their toughness has not been comprehensively investigated. Here we report the Charpy impact behavior and the corresponding microstructural evolutions in UFG Cu with equi-axed and elongated grains which were prepared by equal channel angular pressing (ECAP) for 2 and 16 passes at room temperature. It is found that their impact toughness (48 J/cm2) is almost comparable to that of coarse grained (CG) Cu: 55 J/cm2. The high strain rate during the Charpy impact was found to enhance the strain hardening capability of the UFG Cu due to the suppression of dynamic dislocation recovery. The crack in the CG Cu was blunted by dislocation-slip mediated plastic deformation, while the cracks in the UFG Cu were formed at grain boundaries and triple junctions due to their limited plasticity. Near the crack surfaces the elongated grains in ECAP-2 sample were refined by recrystallization, while equi-axed grains in the ECAP-16 sample grew larger. PMID:28303950

  20. Superior Charpy impact properties of ODS ferritic steel irradiated in JOYO

    Science.gov (United States)

    Kuwabara, T.; Kurishita, H.; Ukai, S.; Narui, M.; Mizuta, S.; Yamazaki, M.; Kayano, H.

    1998-10-01

    The effect of neutron irradiation on Charpy impact properties of an ODS ferritic steel developed by PNC was studied. The miniaturized Charpy V-notch (MCVN) specimens (1.5 × 1.5 × 20 mm) of two orientations (longitudinal, called 1DS-L, and transverse, 1DS-T) were irradiated to fluence levels of (0.3-3.8) × 10 26 n/m 2 ( E n > 0.1 MeV) between 646 and 845 K in JOYO. MCVN specimens before and after the irradiation were subjected to instrumented Charpy impact tests. The test results and fracture surface observations showed that in the unirradiated state the steel showed no ductile-to-brittle transition behavior until 153 K regardless of orientation and the upper shelf energy of the steel was as high as that of a high-strength ferritic steel without dispersed oxide. Such excellent impact properties were essentially maintained after the irradiation although an appreciable decrease in absorbed energy occurred by higher temperature irradiations at and above 793 K.

  1. A Calibration of the Wierzbicki-Xue Damage Model Using Charpy Test Results

    Directory of Open Access Journals (Sweden)

    Kim Jong-Bong

    2015-01-01

    Full Text Available Damage models are frequently used to predict fractures in large deformation problems such as penetration of a projectile into a target. Though many damage models have been proposed so far, coefficients of each model have been provided for only a few materials. In this study, the coefficients of the Wierzbicki-Xue (2005 damage model for tungsten heavy alloy (DX2HCMF are determined using the Charpy impact test. The Wierzbicki-Xue fracture criterion is implemented into NET3D code in which a node-split algorithm is built in. By comparing the energy absorbed in the Charpy test with the results of finite element analysis, the fracture model coefficients are determined.

  2. Influence of Stacking Sequence and Notch Angle on the Charpy Impact Behavior of Hybrid Composites

    Science.gov (United States)

    Behnia, S.; Daghigh, V.; Nikbin, K.; Fereidoon, A.; Ghorbani, J.

    2016-09-01

    The low-velocity impact behavior of hybrid composite laminates was investigated. The epoxy matrix was reinforced with aramid, glass, basalt, and carbon fabrics using the hand lay-up technique. Different stacking sequences and notch angles were and notch angles considered and tested using a Charpy impact testing machine to study the hybridization and notch angle effects on the impact response of the hybrid composites. The energy absorption capability of specimens with different stacking sequences and notch angles is compared and discussed. It is shown that the hybridization can enhance the mechanical performance of composite materials.

  3. Experimental study on variations in Charpy impact energies of low carbon steel, depending on welding and specimen cutting method

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaorui; Kang, Hansaem; Lee, Young Seog [Chung-Ang University, Seoul (Korea, Republic of)

    2016-05-15

    This paper presents an experimental study that examines variations of Charpy impact energy of a welded steel plate, depending upon the welding method and the method for obtaining the Charpy specimens. Flux cored arc welding (FCAW) and Gas tungsten arc welding (GTAW) were employed to weld an SA516 Gr. 70 steel plate. The methods of wire cutting and water-jet cutting were adopted to take samples from the welded plate. The samples were machined according to the recommendations of ASTM SEC. II SA370, in order to fit the specimen dimension that the Charpy impact test requires. An X-ray diffraction (XRD) method was used to measure the as-weld residual stress and its redistribution after the samples were cut. The Charpy impact energy of specimens was considerably dependent on the cutting methods and locations in the welded plate where the specimens were taken. The specimens that were cut by water jet followed by FCAW have the greatest resistance-to-fracture (Charpy impact energy). Regardless of which welding method was used, redistributed transverse residual stress becomes compressive when the specimens are prepared using water-jet cutting. Meanwhile, redistributed transverse residual stress becomes tensile when the specimens are prepared using wire cutting.

  4. Fracture toughness and Charpy impact properties of several RAFMS before and after irradiation in HFIR

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, M.A. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6151 (United States)]. E-mail: sokolovm@ornl.gov; Tanigawa, H. [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Odette, G.R. [University of California-Santa Barbara, Santa Barbara, CA 93106-5080 (United States); Shiba, K. [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Klueh, R.L. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6151 (United States)

    2007-08-01

    As part of the development of candidate reduced-activation ferritic steels for fusion applications, several steels, namely F82H, 9Cr-2WVTa steels and F82H weld metal, are being investigated in the joint DOE-JAEA collaboration program. Within this program, three capsules containing a variety of specimen designs were irradiated at two design temperatures in the ORNL High Flux Isotope Reactor (HFIR). Two capsules, RB-11J and RB-12J, were irradiated in the HFIR removable beryllium positions with europium oxide (Eu{sub 2}O{sub 3}) thermal neutron shields in place. Specimens were irradiated up to 5 dpa. Capsule JP25 was irradiated in the HFIR target position to 20 dpa. The design temperatures were 300 {sup o}C and 500 {sup o}C. Precracked third-sized V-notch Charpy (3.3 x 3.3 x 25.4 mm) and 0.18 T DC(T) specimens were tested to determine transition and ductile shelf fracture toughness before and after irradiation. The master curve methodology was applied to evaluate the fracture toughness transition temperature, T {sub 0}. Irradiation induced shifts of T {sub 0} and reductions of J {sub Q} were compared with Charpy V-notch impact properties. Fracture toughness and Charpy shifts were also compared to hardening results.

  5. 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.

  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

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T. E-mail: yamataku@fusion.imr.tohoku.ac.jp; Odette, G.R.; Lucas, G.E.; Matsui, H

    2000-12-01

    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, {sigma}{sup *}, and critical stressed area, A{sup *}. Since {sigma}{sup *}-A{sup *} is independent of size and geometry, it provides a fundamental local measure of cleavage toughness.

  7. Investigation of some problems in developing standards for precracked Charpy slow bend tests

    Science.gov (United States)

    Succop, G.; Bubsey, R. T.; Jones, M. H.; Brown, W. F., Jr.

    1977-01-01

    The reported investigation was undertaken in connection with an attempt to develop procedures which would be useful in standardizing a test method for the precracked Charpy slow bend specimen. A number of alloys was studied for which valid plane-strain fracture toughness values have been established. The investigation shows that useful relations between precracked Charpy slow bend results and crack size factors can be obtained under some circumstances. However, it is not yet known what factors control these circumstances.

  8. EUROFER 97. Tensile, charpy, creep and structural tests

    Energy Technology Data Exchange (ETDEWEB)

    Rieth, M.; Schirra, M.; Falkenstein, A.; Graf, P.; Heger, S.; Kempe, H.; Lindau, R.; Zimmermann, H.

    2003-10-01

    EUROFER 97 - the European reference material for the first wall of a DEMO fusion reactor - was produced as 3.5 t batch of rods and plates. Following the history of the development activities from conventional martensitic 12% Cr steel, MANET and OPTIFER up to the low or reduced activation (RAFM) EUROFER steel, results obtained from experiments on specimens from rods (diameter 100 mm) and plates (14 mm) are presented for a basic characterization. Physical and mechanical properties are compared with those of OPTIFER-1W and the F82H-mod 2% W steel. The transition behaviour was determined by plotting a continuous TTT (time temperature transition) diagram. In addition, extension coefficients were determined from room temperature up to 1000 C. Hardening tests at temperatures from 850 C to 1120 C illustrated the range of maximum hardness as well as grain size development. Tempering tests and additional annealing experiments from 300 C to 875 C allowed characterizing tempering behaviour and stability. Charpy properties were examined for various heat treatments and specimen types between 60 C and -100 C. Further, ductility criteria like FATT, DBTT and 68 J were determined. Particular attention was paid to the influence of grain size and O{sub 2} content. Tensile strength was measured for several heat treatments between room temperature and 700 C. Long-term ageing was investigated by means of stabilization annealing experiments. These were carried out with various temperature/time combinations including tensile tests. In EUROFER tensile strength was hardly affected by the different heat treatments while the ductility criteria showed only a moderate increase in temperature. Therefore, it can be concluded that EUROFER is not susceptible to ageing. Creep and creep rupture properties were investigated in the temperature range of 450 C to 650 C. So far, creep times of up to 15000 h have been covered by the experiments. The status of the test program allows for an extrapolation of

  9. Certification of Charpy V-Notch Reference Test Pieces of 30 J Nominal Absorbed Energy - Certified Reference Materials ERM®-FA013bg and ERM®-FA013bh

    OpenAIRE

    LAMBERTY MARIE ANDREE; Dean, Alan; Roebben, Gert

    2011-01-01

    This certification report describes the processing and characterisation of ERM®-FA013bg and ERM®-FA013bh, two batches of Charpy V-notch certified reference test pieces. Sets of five of these test pieces are used for the verification of pendulum impact test machines according to EN 10045-2 (Charpy impact test on metallic materials, Part 2. Method for the verification of impact testing machines [1]) or according to ISO 148-2 (Metallic materials - Charpy pendulum impact test - Part 2: Verificati...

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

    Energy Technology Data Exchange (ETDEWEB)

    Buirette, Christophe, E-mail: christophe.buirette@ensiacet.fr [Institut Carnot CIRIMAT, ENSIACET, 4 allée Emile Monso, 31030 Toulouse (France); Huez, Julitte, E-mail: julitte.huez@ensiacet.fr [Institut Carnot CIRIMAT, ENSIACET, 4 allée Emile Monso, 31030 Toulouse (France); Gey, Nathalie, E-mail: Nathalie.gey@univ-lorraine.fr [Laboratoire d’Etude des Microstructures et de Mécanique des Matériaux (LEM3), UMR CNRS 7239, Université de Lorraine, Île du Saulcy, 57045 METZ Cedex 1 (France); DAMAS, Laboratory of Excellence on Design of Alloy Metals for Low-Mass Structures, Université de Lorraine (France); Vassel, Alain, E-mail: alain.vassel@titane.asso.fr [Association Française du Titane, 16 quai Ernest Renaud, BP 70515, 44105 Nantes Cedex 4 (France); Andrieu, Eric, E-mail: eric.andrieu@ensiacet.fr [Institut Carnot CIRIMAT, ENSIACET, 4 allée Emile Monso, 31030 Toulouse (France)

    2014-11-17

    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. 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.

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

    Science.gov (United States)

    Ohtsuka, N.; Shindo, Y.; Makita, A.

    2010-06-01

    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 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. The evaluation of tempered martensite embrittlement in 4130 steel by instrumented charpy V-notch testing

    Science.gov (United States)

    Zia-Ebrahimi, F.; Krauss, G.

    1983-06-01

    Tempered martensite embrittlement (TME) was studied in vacuum-melted 4130 steel with either 0.002 or 0.02 wt pct P. TME was observed as a severe decrease in Charpy V-notch impact energy, from 46 ft-lb. at 200 °C to 35 ft-lb. at 300 °C in the low P alloy. The impact energy of the high P alloy was consistently lower than that of the low P alloy in all tempered conditions. Fracture was transgranular for all specimens; therefore, segregation of P to the prior austenitic grain boundaries was not a factor in the o°Currence of TME. Analysis of load-time curves obtained by instrumented Charpy testing revealed that the embrittlement is associated with a drop in the pre-maximum-load and post-unstable-fracture energies. In specimens tempered at 400 °C the deleterious effect of phosphorus on impact energy became pronounced, a result more consistent with classical temper embrittlement rather than TME. A constant decrease in pre-maximum-load energy due to phosphorus content was observed. The pre-maximum-load energy decreases with increasing tempering temperature in the range of 200 °C to 400 °C, a result explained by the change in work hardening rate. Carbon extraction replicas of polished and etched as-quenched specimens revealed the presence of Fe2MoC and/or Fe3C carbides retained after austenitizing. Ductile crack extension close to the notch root was related to the formation of fine micro voids at the retained carbides.

  14. Material inertia and size effects in the Charpy V-notch test

    DEFF Research Database (Denmark)

    Desandre, D. A.; Benzerga, A. A.; Tvergaard, Viggo;

    2004-01-01

    The effect of material inertia on the size dependence of the absorbed energy in the Charpy V-notch test is investigated. The material response is characterized by an elastic-viscoplastic constitutive relation for a porous plastic solid, with adiabatic heating due to plastic dissipation and the re......The effect of material inertia on the size dependence of the absorbed energy in the Charpy V-notch test is investigated. The material response is characterized by an elastic-viscoplastic constitutive relation for a porous plastic solid, with adiabatic heating due to plastic dissipation...

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

    Science.gov (United States)

    Haušild, Petr; Materna, Aleš; Kytka, Miloš

    2015-04-01

    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.

  17. 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.

  18. 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.

  19. 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.

  20. Unnotched Charpy Impact Energy Transition Behavior of Austempered Engineering Grade Ductile Iron Castings

    Science.gov (United States)

    Kisakurek, Sukru Ergin; Ozel, Ahmet

    2014-04-01

    Unnotched Charpy impact energy transition behavior of five different engineering grade ductile iron castings, as specified by EN 1563 Standards, were examined in as-cast, as well as in austempered states. ADIs were produced with the maximum impact energy values permissible for the grades. Austempering treatment detrimented the sub-zero impact properties of the ferritic castings, but considerably enhanced those of the pearlitic-ferritic irons. The impact energy transition behavior of the austempered states of all the grades examined were noted to be determined by the progressive transformation of the unavoidable carbon-unsaturated and untransformed regions of the austenite remaining in the matrix of the austempered ductile iron to martensite with decreasing temperature.

  1. Effect of Cadmium Plating Thickness on the Charpy Impact Energy of Hydrogen-Charged 4340 Steel

    Science.gov (United States)

    Es-Said, O. S.; Alcisto, J.; Guerra, J.; Jones, E.; Dominguez, A.; Hahn, M.; Ula, N.; Zeng, L.; Ramsey, B.; Mulazimoglu, H.; Li, Yong-Jun; Miller, M.; Alrashid, J.; Papakyriakou, M.; Kalnaus, S.; Lee, E. W.; Frazier, W. E.

    2016-09-01

    Hydrogen was intentionally introduced into ultra-high strength steel by cadmium plating. The purpose was to examine the effect of cadmium plate thickness and hence hydrogen on the impact energy of the steel. The AISI 4340 steel was austenitized at 1000 °C for 1 h, water quenched, and tempered at temperatures between 257 and 593 °C in order to achieve a range of targeted strength levels. The specimens were cadmium plated with 0.00508 mm (0.2 mils), 0.00762 mm (0.3 mils), and 0.0127 mm (0.5 mils). Results demonstrated that the uncharged specimens exhibited higher impact energy values when compared to the plated specimens at all tempering temperatures. The cadmium-plated specimens had very low Charpy impact values irrespective of their ultimate tensile strength values. The model of hydrogen transport by mobile dislocations to the fracture site appears to provide the most suitable explanation of the results.

  2. An improved correlation procedure for subsize and full-size Charpy impact specimen data

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, M.A.; Alexander, D.J. [Oak Ridge National Lab., TN (United States)

    1997-03-01

    The possibility of using subsize specimens to monitor the properties of reactor pressure vessel steels is receiving increasing attention for light-water reactor plant life extension. This potential results from the possibility of cutting samples of small volume form the internal surface of the pressure vessel for determination of the actual properties of the operating pressure vessel. In addition, plant life extension will require supplemental data that cannot be provided by existing surveillance programs. Testing of subsize specimens manufactured from broken halves of previously tested surveillance Charpy specimens offers an attractive means of extending existing surveillance programs. Using subsize Charpy V-notch-type specimens requires the establishment of a specimen geometry that is adequate to obtain a ductile-to-brittle transition curve similar to that obtained from full-size specimens, and the development of correlations for transition temperature and upper-shelf energy (USE) level between subsize and full-size specimens. Five different geometries of subsize specimens were selected for testing and evaluation. The specimens were made from several types of pressure vessel steels with a wide range of yield strengths, transition temperatures, and USEs. The effects of specimen dimensions, including notch depth, angle, and radius, have been studied. The correlations of transition temperatures determined from different types of subsize specimens and the full-size specimens are presented. A new procedure for transforming data from subsize specimens is developed. The transformed data are in good agreement with data from full-size specimens for materials that have USE levels less than 200 J.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.; Scibetta, M.; Puzzolante, L.

    2008-10-15

    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.

  4. Ultrahigh Charpy impact toughness (~450J) achieved in high strength ferrite/martensite laminated steels

    Science.gov (United States)

    Cao, Wenquan; Zhang, Mingda; Huang, Chongxiang; Xiao, Shuyang; Dong, Han; Weng, Yuqing

    2017-01-01

    Strength and toughness are a couple of paradox as similar as strength-ductility trade-off in homogenous materials, body-centered-cubic steels in particular. Here we report a simple way to get ultrahigh toughness without sacrificing strength. By simple alloying design and hot rolling the 5Mn3Al steels in ferrite/austenite dual phase temperature region, we obtain a series of ferrite/martensite laminated steels that show up-to 400–450J Charpy V-notch impact energy combined with a tensile strength as high as 1.0–1.2 GPa at room temperature, which is nearly 3–5 times higher than that of conventional low alloy steels at similar strength level. This remarkably enhanced toughness is mainly attributed to the delamination between ferrite and martensite lamellae. The current finding gives us a promising way to produce high strength steel with ultrahigh impact toughness by simple alloying design and hot rolling in industry. PMID:28150692

  5. Ultrahigh Charpy impact toughness (~450J) achieved in high strength ferrite/martensite laminated steels.

    Science.gov (United States)

    Cao, Wenquan; Zhang, Mingda; Huang, Chongxiang; Xiao, Shuyang; Dong, Han; Weng, Yuqing

    2017-02-02

    Strength and toughness are a couple of paradox as similar as strength-ductility trade-off in homogenous materials, body-centered-cubic steels in particular. Here we report a simple way to get ultrahigh toughness without sacrificing strength. By simple alloying design and hot rolling the 5Mn3Al steels in ferrite/austenite dual phase temperature region, we obtain a series of ferrite/martensite laminated steels that show up-to 400-450J Charpy V-notch impact energy combined with a tensile strength as high as 1.0-1.2 GPa at room temperature, which is nearly 3-5 times higher than that of conventional low alloy steels at similar strength level. This remarkably enhanced toughness is mainly attributed to the delamination between ferrite and martensite lamellae. The current finding gives us a promising way to produce high strength steel with ultrahigh impact toughness by simple alloying design and hot rolling in industry.

  6. Charpy Impact Response of the Cracked Aluminum Plates Repaired with FML Patches using the Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Faramarz Ashenai Ghasemi

    2016-09-01

    Full Text Available Here, the effect of fiber metal laminate (FMLs patches was studied for repairing of single-sided cracked aluminum plates experimentally to see their response to Charpy impact tests. The main desired parameters were composite patch lay-up, crack length, and crack angle each one in three levels. All experimental attempts generated and followed based on the design of experiments method by using of response surface methodology. The predicted energy absorption values obtained from the model were in good agreement with the experimental results. No matter the specimens were repaired or not, as the crack length was increased the energy absorption of the structure was decreased. The experimental results also showed that for lengthen cracks, increasing of the crack angle had more effect on energy absorption. Also it was observed that the patch lay-up effective on the impact response of the specimens. The more the metal layer was departed from the aluminum plate and the FML patches interfacial surface, the less energy was absorbed in the structure.

  7. Instrumented Impact Testing Using a Hopkinson Bar Apparatus

    Science.gov (United States)

    1975-07-01

    revert« «Id» II necnnvv *nd identity by ftfoeft number) A technique for conducting instrumented Charpy impact tests using a Hopkin- son bar is...materi- al--; obtained from an instrumented impact test at 54 in/sec (1.37 m/s) and from a standard Charpy impact machine at 135 in/sec (3.43 m/s...arises as to how important wave reflections might be in the interpretation of experimental data from an instrumented Charpy impact test . In

  8. 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.

  9. 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)

  10. Instrumented impact testing machine with reduced specimen oscillation effects

    Science.gov (United States)

    Rintamaa, R.; Ranka, K.; Wallin, K.; Ikonen, K.; Talja, H.; Kotilainen, H.; Sirkkola, E.

    1984-07-01

    A pendulum-type instrumented Charpy test apparatus based on inverted test geometry was developed. Geometry inversion reduces inertia load and specimen oscillation effects. Initial impact energy is double that of standard (300 J) impact testers, allowing the use of larger (10 x 20 x 110 mm) bend specimens than normal Charpy specimens. The rotation axis in the three point bending is nearly stationary, making COD-measurements possible. Inertia effects and specimen oscillations are compared with the conventional tester, and using an analytical finite element model for Charpy V-notch specimens. Better performance for the inverted geometry is reported.

  11. Effect of low temperatures on charpy impact toughness of austempered ductile irons

    Science.gov (United States)

    Riabov, Mikhail V.; Lerner, Yury S.; Fahmy, Mohammed F.

    2002-10-01

    Impact properties of standard American Society for Testing Materials (ASTM) grades of austempered ductile iron (ADI) were evaluated at subzero temperatures in unnotched and V-notched conditions and compared with ferritic and pearlitic grades of ductile irons (DIs). It was determined that there is a decrease in impact toughness for all ADI grades when there is a decrease in content of retained austenite and a decrease in test temperature, from room temperature (RT) to -60 °C. However, the difference in impact toughness values was not so noticeable for low retained austenite containing grade 5 ADI at both room and subzero temperatures as it was for ADI grade 1. Furthermore, the difference in impact toughness values of V-notched specimens of ADI grades 1 and 5 tested at -40 °C was minimal. The impact behaviors of ADI grade 5 and ferritic DI were found to be more stable than those of ADI grades 1, 2, 3, and 4 and pearlitic DI when the testing temperature was decreased. The impact toughness of ferritic DI was higher than that of ADI grades 1 and 2 at both -40 °C and -60 °C. The impact properties of ADI grades 4 and 5 were found to be higher than that of pearlitic DI at both -40 °C and -60 °C. The scanning electron microscopy (SEM) study of fracture surfaces revealed mixed ductile and quasicleavage rupture morphology types in all ADI samples tested at both -40 °C and -60 °C. With decreasing content of retained austenite and ductility, the number of quasicleavage facets increased from ADI grade 1-5. It was also found that fracture morphology of ADI did not experience significant changes when the testing temperature decreased. Evaluation of the bending angle was used to support impact-testing data. Designers and users of ADI castings may use the data developed in this research as a reference.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E

    1999-04-01

    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.

  13. Weld investigations by 3D analyses of Charpy V-notch specimens

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Needleman, Allan

    2005-01-01

    The Charpy impact test is a standard procedure for determining the ductile-brittle transition in welds. The predictions of such tests have been investigated by full three dimensional transient analyses of Charpy V-notch specimens. The material response is characterised by an elastic-viscoplastic ......The Charpy impact test is a standard procedure for determining the ductile-brittle transition in welds. The predictions of such tests have been investigated by full three dimensional transient analyses of Charpy V-notch specimens. The material response is characterised by an elastic...... parameters in the weld material differ from those in the base material, and the heat a®ected zone (HAZ) tends to be more brittle than the other material regions. The effect of weld strength undermatch or overmatch is an important issue. Some specimens, for which the notched surface is rotated relative...

  14. Low-energy charpy impact of interleaved CF/EP laminates

    Science.gov (United States)

    Yuan, Q.; Friedrich, K.; Karger-Kocsis, J.

    1995-03-01

    Carbon fiber (CF) reinforced epoxy (CF/EP) laminates laid up in different ways (cross-ply and quasi-isotropic) with and without various adhesive interlayers (A) were studied under three-point bending using instrumented low-energy impact at single and multiple bounces. Interleaves were a modified EP resin on polyester fabric, a modified EP resin, and a polyethersulphone (PES) film. The impact response depends strongly on whether the CFs are oriented longitudinally (L) or transversely (T) to the hammer edge in the outer bounced ply. The threshold incident energy ( E in,th) associated with severe damage to the laminates was much lower with the longitudinal outer ply. The impact fatigue response of the transverse cross-ply (TCP) and quasi-isotropic (TQI) composite beams showed that stiffness degradation starts at a certain a threshold number of impact (NOI) and follows a logarithmic decay as a function of NOI. This is in close analogy to fatigue tests under usual conditions. Deterioration in stiffness can be assigned to the relative change in the secant slope ( E max/ x max) of the load-displacement ( F-x) traces. The related load-time ( F-t) traces flatten due to impact fatigue so that their load maximum ( F max) shifts toward higher contact time. The efficiency of the interleaving was assessed in both single (at E in,th≈3 J) and repeated impact (at E in=1 J). The first technique allowed us to differentiate between the various interleaves, whereas the latter contributed to finding the optimum stacking and position of the interleaves.

  15. Transferability of Charpy Absorbed Energy to Fracture Toughness Based on Weibull Stress Criterion

    Institute of Scientific and Technical Information of China (English)

    Hongyang JING; Lianyong XU; Lixing HUO; Fumiyoshi Minami

    2005-01-01

    The relationship between Charpy absorbed energy and the fracture toughness by means of the (crack tip opening displacement (CTOD)) method was analyzed based on the Weibull stress criterion. The Charpy absorbed energy and the fracture toughness were measured for the SN490B steel under the ductile-brittle transition temperature region. For the instrumented Charpy impact test, the curves between the loading point displacement and the load against time were recorded. The critical Weibull stress was taken as a fracture controlled parameter, and it could not be affected by the specimen configuration and the loading pattern based on the local approach. The parameters controlled brittle fracture are obtained from the Charpy absorbed energy results, then the fracture toughness for the compact tension (CT) specimen is predicted. It is found that the results predicted are in good agreement with the experimental. The fracture toughness could be evaluated by the Charpy absorbed energy, because the local approach gives a good description for the brittle fracture even though the Charpy impact specimen or the CT specimen is used for the given material.

  16. Irradiation programme MANITU: Results of pre-examinations and Charpy tests with unirradiated materials; Bestrahlungsprogramm MANITU. Ergebnisse der Voruntersuchungen und der Kerbschlagbiegeversuche mit den unbestrahlten Werkstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Rieth, M.; Dafferner, B.; Ries, H.; Romer, O.

    1995-04-01

    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.) [Deutsch] Das Bestrahlungsprojekt MANITU wurde im Rahmen des europaeischen Langzeitprogramms fuer Materialentwicklung fuer die Kernfusion geplant. Die daraus gewonnenen Ergebnisse werden das weitere Vorgehen bei der Materialentwicklung entscheidend beeinflussen. Das Problem der bestrahlungsinduzierten Versproedung bei den in Frage kommenden martensitischen Werkstoffen ist nach wie vor ungeloest. Eine erste Tendenz zeichnet sich nach der Auswertung der Kerbschlagbiegeversuche an den unbestrahlten miniaturisierten Referenzproben des MANITU-Programms ab. Die neu entwickelten niedrig aktivierbaren 7-10% Cr-WVTa-Legierungen weisen gegenueber den modifizierten kommerziellen 10-11% Cr-NiMoVNb-Staehlen deutlich bessere Kerbschlageigenschaften auf. Im vorliegenden Bericht werden die Voruntersuchungen dokumentiert und die Ergebnisse aus den Kerbschlagbiegeversuchen der unbestrahlten Referenzproben analysiert und bewertet. (orig.)

  17. 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.

  18. Instrumented Charpy Impact Testing and Dynamic Fracture Toughness of 30CrNi2MoV Steel of Frac-pump Fluid Cylinder%压裂泵阀箱用钢的示波冲击性能及动态断裂韧性

    Institute of Scientific and Technical Information of China (English)

    王国荣; 陈林燕; 肖晓华; 李蓉

    2014-01-01

    对30CrNi2MoV压裂泵阀箱用钢进行880℃淬火+560~650℃回火的调质处理,在室温下进行了CharpyV型缺口示波冲击试验,通过SEM对各个回火温度下的冲击断口形貌进行了对比分析.实验结果表明:30CrNi2MoV阀箱钢的延性断裂韧度、动态断裂韧度、裂纹扩展功、冲击功等关键指标均随回火温度的升高而升高.供货态试样断口为解理形貌;560℃回火断口形貌是准解理+韧窝;590~650℃断口是韧窝形貌.冲击韧度和冲击断口形貌有良好的对应关系.

  19. 46 CFR 54.05-20 - Impact test properties for service of 0 °F and below.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Impact test properties for service of 0 °F and below... ENGINEERING PRESSURE VESSELS Toughness Tests § 54.05-20 Impact test properties for service of 0 °F and below. (a) Test energy. The impact energies of each set of transverse Charpy specimens may not be less...

  20. 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)

  1. 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)

  2. 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

  3. 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.

  4. 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.

  5. Impact Resistance of Structural Ceramics. Part 1. Instrumented Drop- Weight Tests

    Science.gov (United States)

    1976-05-01

    instrumented Charpy test and the instrumented DWT. The Impact Fracture Energy of a ceramic is determined by its dynamic strength. At room temperature...AFML-TR-76-56 ~I’S PART I 0 IMPACT RESISTANCE OF STRUCTURAL CERAMICS PART I: INSTRUMENTED DROP-WEIGHT TESTS PROCESSING AND HIGH TEMPERATURE MATERIALS...BLAG..OTP ,fIJMED .. TABLE OF CONTENTS SECTION PAGE I INTRODUCTION 1 II DROP-WEIGHT TEST (DWT) 3 III EXPERIMENTAL PROCEDURES FOR THE INSTRUMENTED DWT AT

  6. 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.

  7. Evaluation of ageing-induced embrittlement in an austenitic stainless steel by instrumented impact testing

    Science.gov (United States)

    Samuel, K. G.; Sreenivasan, P. R.; Ray, S. K.; Rodriguez, P.

    1987-09-01

    Fracture properties of a thermally aged Type 316 stainless steel have been investigated at room temperature by an instrumented impact test. The impact energy is found to depend on the heat treatment conditions. Several alternative estimates for toughness are evaluated and compared with the conventional Charpy impact energy, C v, to assess the degree of embrittlement. Sensitivity of these parameters to monitor the ageing-induced embrittlement in comparison with C v is discussed.

  8. Certification of NIST Room Temperature Low-Energy and High-Energy Charpy Verification Specimens.

    Science.gov (United States)

    Lucon, Enrico; McCowan, Chris N; Santoyo, Ray L

    2015-01-01

    The possibility for NIST to certify Charpy reference specimens for testing at room temperature (21 °C ± 1 °C) instead of -40 °C was investigated by performing 130 room-temperature tests from five low-energy and four high-energy lots of steel on the three master Charpy machines located in Boulder, CO. The statistical analyses performed show that in most cases the variability of results (i.e., the experimental scatter) is reduced when testing at room temperature. For eight out of the nine lots considered, the observed variability was lower at 21 °C than at -40 °C. The results of this study will allow NIST to satisfy requests for room-temperature Charpy verification specimens that have been received from customers for several years: testing at 21 °C removes from the verification process the operator's skill in transferring the specimen in a timely fashion from the cooling bath to the impact position, and puts the focus back on the machine performance. For NIST, it also reduces the time and cost for certifying new verification lots. For one of the low-energy lots tested with a C-shaped hammer, we experienced two specimens jamming, which yielded unusually high values of absorbed energy. For both specimens, the signs of jamming were clearly visible. For all the low-energy lots investigated, jamming is slightly more likely to occur at 21 °C than at -40 °C, since at room temperature low-energy samples tend to remain in the test area after impact rather than exiting in the opposite direction of the pendulum swing. In the evaluation of a verification set, any jammed specimen should be removed from the analyses.

  9. Impact properties of A356-T6 alloys

    Science.gov (United States)

    Shivkumar, S.; Wang, L.; Keller, C.

    1994-02-01

    The Charpy impact energy of A356 alloys has been measured. Instrumented Charpy impact tests have been conducted at 25,100,150, and 200 °C. The Charpy specimens were machined from plate castings ortapered cylindrical castings. The plates were produced in sand molds, and tapered cylinders were produced in water-cooled copper molds. Both unmodified and strontium-modified castings were tested. The results indicate that strontium modification improves the impact properties of sand and permanent mold castings. The impact energy increases with solution treatment time. Strontium modification reduces the solution treatment time for attaining a specific impact property level in the casting.

  10. 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.

  11. Instrumented Impact Testing: Influence of Machine Variables and Specimen Position

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.; McCowan, C. N.; Santoyo, R. A.

    2008-09-15

    An investigation has been conducted on the influence of impact machine variables and specimen positioning on characteristic forces and absorbed energies from instrumented Charpy tests. Brittle and ductile fracture behavior has been investigated by testing NIST reference samples of low, high and super-high energy levels. Test machine variables included tightness of foundation, anvil and striker bolts, and the position of the center of percussion with respect to the center of strike. For specimen positioning, we tested samples which had been moved away or sideways with respect to the anvils. In order to assess the influence of the various factors, we compared mean values in the reference (unaltered) and altered conditions; for machine variables, t-test analyses were also performed in order to evaluate the statistical significance of the observed differences. Our results indicate that the only circumstance which resulted in variations larger than 5 percent for both brittle and ductile specimens is when the sample is not in contact with the anvils. These findings should be taken into account in future revisions of instrumented Charpy test standards.

  12. 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.

  13. The effect of fibre content, fibre size and alkali treatment to Charpy impact resistance of Oil Palm fibre reinforced composite material

    Science.gov (United States)

    Fitri, Muhamad; Mahzan, Shahruddin

    2016-11-01

    In this research, the effect of fibre content, fibre size and alkali treatment to the impact resistance of the composite material have been investigated, The composite material employs oil palm fibre as the reinforcement material whereas the matrix used for the composite materials are polypropylene. The Oil Palm fibres are prepared for two conditions: alkali treated fibres and untreated fibres. The fibre sizes are varied in three sizes: 5mm, 7mm and 10mm. During the composite material preparation, the fibre contents also have been varied into 3 different percentages: 5%, 7% and 10%. The statistical approach is used to optimise the variation of specimen determined by using Taguchi method. The results were analyzed also by the Taguchi method and shows that the Oil Palm fibre content is significantly affect the impact resistance of the polymer matrix composite. However, the fibre size is moderately affecting the impact resistance, whereas the fibre treatment is insignificant to the impact resistance of the oil palm fibre reinforced polymer matrix composite.

  14. Certification of NIST Room Temperature Low-Energy and High-Energy Charpy Verification Specimens

    OpenAIRE

    Lucon, Enrico; McCowan, Chris N.; Santoyo, Ray L.

    2015-01-01

    The possibility for NIST to certify Charpy reference specimens for testing at room temperature (21 °C ± 1 °C) instead of −40 °C was investigated by performing 130 room-temperature tests from five low-energy and four high-energy lots of steel on the three master Charpy machines located in Boulder, CO. The statistical analyses performed show that in most cases the variability of results (i.e., the experimental scatter) is reduced when testing at room temperature. For eight out of the nine lots ...

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

    OpenAIRE

    Cepeda-Jiménez, C.M.; García-Infanta, J.M.; Pozuelo, M.; Ruano, Oscar Antonio; Carreño, Fernando

    2009-01-01

    A multilayer aluminium laminate comprising ten 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, being eighteen times higher than that for the as-received Al-Zn-Mg-Cu alloy. Damage tolerance improvement was due to the high volume fra...

  16. Test Simulation using Finite Element Method

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M B; Abdullah, S; Nuawi, M Z; Ariffin, A K, E-mail: abgbas@yahoo.com [Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia 43600 Bangi, Selangor (Malaysia)

    2011-02-15

    The dynamic responses of the standard Charpy impact machine are experimentally studied using the relevant data acquisition system, for the purpose of obtaining the impact response. For this reason, the numerical analysis by means of the finite element method has been used for experiment findings. Modelling of the charpy test was performed in order to obtain strain in the striker during the test. Two types of standard charpy specimens fabricated from different materials, i.e. aluminium 6061 and low carbon steel 1050, were used for the impact simulation testing. The related parameters on between different materials, energy absorbed, strain signal, power spectrum density (PSD) and the relationship between those parameters was finally correlated and discussed.

  17. 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.

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

    Science.gov (United States)

    Zou, Yu; Zhan, Chang-Yong; Yang, Bin; Wu, Jian-Chun

    2013-05-01

    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.

  19. Standard Guide for Reconstitution of Irradiated Charpy-Sized Specimens

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This guide covers procedures for the reconstitution of ferritic pressure boundary steels used in nuclear power plant applications, Type A Charpy (Test Methods E 23) specimens and specimens suitable for testing in three point bending in accordance with Test Methods E 1921 or E 1820. Materials from irradiation programs (principally broken specimens) are reconstituted by welding end tabs of similar material onto remachined specimen sections that were unaffected by the initial test. Guidelines are given for the selection of suitable specimen halves and end tab materials, for dimensional control, and for avoidance of overheating the notch area. A comprehensive overview of the reconstitution methodologies can be found in Ref (1). 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 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...

  20. Apportion of Charpy energy in API 5L grade X70 pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Sayyed H. [Department of Mechanical Engineering, The University of Birjand, PO Box 97175 /615, Birjand (Iran, Islamic Republic of)], E-mail: shhashemi@birjand.ac.ir

    2008-12-15

    Conventional Charpy based failure models for gas transportation pipelines recommend the minimum fracture energy for safe performance of these structures. In recent years however, full-scale burst experiments have shown that such models cannot fully guarantee the safety of higher grade pipeline steels. One possible reason for this discrepancy, which is further investigated in this research, is that Charpy energy inherently contains both fracture and non-fracture related energy. To separate this, energy partitioning analysis was used. First, the overall fracture energy of X70 steel is measured experimentally on an instrumented Charpy rig. Next, the measured energy is divided into fracture initiation and propagation parts using load-displacement data. It appeared from test results that a significant amount of energy was consumed in non-fracture related processes. From this, correction factors were suggested for possible use in current industry failure models. Interestingly, these corrections factors agreed well with those reported from full-thickness burst tests for tough pipeline steels.

  1. Evaluation of effect of hydrogen on toughness of Zircaloy-2 by instrumented drop weight impact testing

    Science.gov (United States)

    Viswanathan, U. K.; Singh, R. N.; Basak, C. B.; Anantharaman, S.; Sahoo, K. C.

    2006-05-01

    Hydride-assisted degradation in fracture toughness of Zircaloy-2 was evaluated by carrying out instrumented drop-weight tests on curved Charpy specimens fabricated from virgin pressure tube. Samples were charged to 60 ppm and 225 ppm hydrogen. Ductile-to-brittle-transition behaviour was exhibited by as-received and hydrided samples. The onset of ductile-to-brittle-transition was at about 130 °C for hydrided samples, irrespective of their hydrogen content. Dynamic fracture toughness ( KID) was estimated based on linear elastic fracture mechanics (LEFM) approach. For fractures occurring after general yielding, the fracture toughness was derived based on equivalent energy criterion. Results are supplemented with fractography. This simple procedure of impact testing appears to be promising for monitoring service-induced degradation in fracture toughness of pressure tubes.

  2. A study of the fracture process and factors that control toughness variability in Charpy V-notch specimens

    Science.gov (United States)

    Bouchard, Real

    La presente etude a ete initiee pour developper une comprehension quantitative du processus de rupture avec les facteurs qui controlent la dispersion des mesures de tenacite lorsque des eprouvettes Charpy entaillees en V sont utilisees. Un grand nombre d'essais ont ete realises pour un acier C-Mn: eprouvettes Charpy testees sous impact, eprouvettes Charpy testees en flexion lente, eprouvettes axisymetriques entaillees et sollicitees en traction et essais de tenacite sur eprouvettes prefissurees. Base sur le concept de la statistique de Weibull, l'approche locale developpee par le groupe Beremin a ete utilisee pour decrire la probabilite de rupture par clivage en fonction de la contrainte appliquee aussi bien qu'en fonction de l'energie Charpy obtenue. Le calcul par elements finis a ete realise pour determiner la distribution de la deformation et des contraintes en pointe d'entaille et de fissure. La nouvelle approche introduite decrit bien les resultats experimentaux. Les points d'initiation du clivage ont ete identifies au MEB et par la suite, avec la technique de faisceau d'ions focalise, sectionnes, polis et examines. L'examen de la microstructure sous le point d'initiation revele clairement que le clivage s'initie par un mecanisme d'empilement de dislocations ou les dislocations sont arretees aux joints de grain, aux interfaces de perlite/ferrite ou de perlite qui agissent comme barrieres physiques.

  3. Numerical and experimental evaluation of the impact performance of advanced high-strength steel sheets based on a damage model

    Science.gov (United States)

    Ma, Ning; Park, Taejoon; Kim, Dongun; Kim, Chongmin; Chung, Kwansoo

    2010-06-01

    The impact performance in a Charpy impact test was experimentally and numerically studied for the advanced high-strength steel sheets (AHSS) TWIP940 and TRIP590 as well as the high-strength grade known as 340R. To characterize the mechanical properties, uni-axial simple tension tests were conducted to determine the anisotropic properties and strain rate sensitivities of these materials. In particular, the high-speed strain-rate sensitivity of TRIP590 and 340R (rate sensitive) was also characterized to account for the high strain rates involved in the Charpy impact test. To evaluate fracture behavior in the Charpy impact test, a new damage model including a triaxiality-dependent fracture criterion and hardening behavior with stiffness deterioration was introduced. The model was calibrated via numerical simulations and experiments involving simple tension and V-notch tests. The new damage model along with the anisotropic yield function Hill 1948 was incorporated into the ABAQUS/Explicit FEM code, which performed reasonably well to predict the impact energy absorbed during the Charpy impact test.

  4. Glatz Prototype Seat Impact Testing

    Science.gov (United States)

    2013-07-03

    thrust piston, the sled coasts to a stop or is stopped with a triggered pneumatic brake system. The impact acceleration is roughly sinusoidal. HIA...all PH testing. The HIA consists of a 4 ft by 8 ft sled positioned on a 204 ft long track and is accelerated using a 24 inch diameter pneumatic

  5. Influence of Loading Rate on the Calibration of Instrumented Charpy Strikers

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.; Scibetta, M.; McColskey, D.; McCowan, C.

    2009-01-15

    One of the key factors for obtaining reliable instrumented Charpy results is the calibration of the instrumented striker. The conventional approach for establishing an analytical relationship between strain gage output and force applied to the transducer is the static calibration, which is preferably performed with the striker installed in the pendulum assembly. However, the response of an instrumented striker under static force application may sometimes differ significantly from its dynamic performance during an actual Charpy test. This is typically reflected in a large difference between absorbed energy returned by the pendulum encoder (KV) and calculated under the instrumented force/displacement test record (Wt). Such difference can be either minimized by optimizing the striker design or analytically removed by adjusting forces and displacements until KV = Wt (the so-called 'Dynamic Force Adjustment'). This study investigates the influence of increasing force application rates on the force/voltage characteristics of two instrumented strikers, one at NIST in Boulder, CO and one at SCK-CEN in Mol, Belgium.

  6. Fracture process of a low carbon low alloy steel relevant to charpy toughness at ductile-brittle fracture transition region

    Science.gov (United States)

    Tani, T.; Nagumo, M.

    1995-02-01

    The fracture process that determines the Charpy energy at the ductile-brittle transition region was investigated by means of the instrumented Charpy test and fractographic analysis with a low carbon low alloy steel subjected to different control-rolling conditions. The decomposition of a Charpy energy into the energies dissipated in the course of the notch-tip blunting, stable crack growth, and brittle crack propagation is unique irrespective of the testing temperatures and specimen series. Toughness level can be divided into four regions according to the pre-dominating fracture process. The temperature dependence of toughness and effects of the an-isotropy of a specimen originates in the brittle fracture initiation stage rather than the resistance against the notch-tip blunting or stable crack growth. From fractographic examination referring to the stress analyses, it is discussed that the brittle fracture initiation is controlled by the local deformation microstructures in the plastic zone together with the stress field ahead of the notch or the stable crack front.

  7. Mechanical characterization based in the impact test of the cadmium-zinc and cadmium-zinc-copper alloys; Caracterizacion mecanica basada en la prueba de impacto de las aleaciones cadmio-zinc y cadmio-zinc-cobre

    Energy Technology Data Exchange (ETDEWEB)

    Casolco, S.R.; Torres V, G. [Instituto de Investigacion en Materiales, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, 04510 Mexico D.F. (Mexico)

    1999-11-01

    The present work is a study carried out in the Institute for Materials Research of the UNAM, of the alloys cadmium-zinc and cadmium-zinc-copper with the fundamental objective of knowing their behavior to the impact that which will allow to establish structural applications of these alloys. This work consists mainly on impact tests of the type Charpy at different temperatures in a range of - 150 Centigrade to 250 Centigrade and to study their fracture morphologies with the help of a scanning electron microscope to recognize the tendency of the material toward the fracture of the fragile type and to determine the ductile-fragile transition. (Author)

  8. Low temperature impact testing of welded structural wrought iron

    Science.gov (United States)

    Rogers, Zachary

    During the second half of the 19th century, structural wrought iron was commonly used in construction of bridges and other structures. Today, these remaining structures are still actively in use and may fall under the protection of historic preservation agencies. Continued use and protection leads to the need for inspection, maintenance, and repair of the wrought iron within these structures. Welding can be useful to achieve the appropriate repair, rehabilitation, or replacement of wrought iron members. There is currently very little published on modern welding techniques for historic wrought iron. There is also no pre-qualified method for this welding. The demand for welding in the repair of historic structural wrought iron has led to a line of research investigating shielded metal arc welding (SMAW) of historic wrought iron at the University of Colorado Denver. This prior research selected the weld type and other weld specifications to try and achieve a recognized specific welding procedure using modern SMAW technology and techniques. This thesis continues investigating SMAW of historic wrought iron. Specifically, this thesis addresses the toughness of these welds from analysis of the data collected from performing Charpy V-Notch (CVN) Impact Tests. Temperature was varied to observe the material response of the welds at low temperature. The wrought iron used in testing was from a historic vehicle bridge in Minnesota, USA. This area, and many other areas with wrought iron structures, can experience sustained or fluctuating temperatures far below freezing. Investigating the toughness of welds in historic wrought iron at these temperatures is necessary to fully understand material responses of the existing structures in need of maintenance and repair. It was shown that welded wrought iron is tougher and more ductile than non-welded wrought iron. In regards to toughness, welding is an acceptable repair method. Information on wrought iron, low temperature failure

  9. 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.)

  10. Analysis of the Charpy V-notch test for welds

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Needleman, A.

    2000-01-01

    strength variations in a weldment in a HY100 steel. The predicted work to fracture shows a strong sensitivity to the location of the notch relative to the weld, with the most brittle behavior for a notch close to the narrow heat affected zone. The analyses illustrate the strong dependence of the transition...

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

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R.; Scibetta, M.; Van Walle, E.; Gerard, R

    1999-08-01

    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, T{sub 0}, 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 K{sub IC} curve trends to be over conservative. Replacing RT{sub NDT} by the new index, RT{sub To}, in the ASME KIC equation reduces this over conservatism.

  12. Test Technique Development on the Irradiated Reconstituted PCVN Specimen in Hot Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sangbok; Oh, Wanho; Choo, Yongsun; Kim, Minchul; Lee, Bongsang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    The degradation of fracture toughness is the important factor to restrict the life of nuclear pressure vessel in PWR reactors. A pressure vessel is operated in conformity with the fracture analysis based on ASME codes to ensure safety margins from the unstable fracture. A fracture analysis is performed based on the result from the Charpy impact tests in PWR reactor, but it has the questions to be exact solutions because the test results give indirect and excessively conservative values. Therefore the research to find an exact toughness parameter is undergoing to use the pre-cracked Charpy v-notch (PCVN). As results the master curve method is proposed in ASTM E1921 to be supposed an appropriate tool to evaluate the fracture toughness for the irradiated, or the operated pressure vessel materials. The surveillance test program to evaluate toughness degradation on existing commercial PWR reactor is performed through the impact test on Charpy specimens. It gives the lack of the specimen to evaluate the safety in toughness for on-going operation beyond design life. To overcome the shortage of specimen, the test method to use a reconstituted PCVN specimen fabricated from the broken half of Charpy specimen is proposed and adopted in foreign reactors. In this paper techniques developed for the reconstituted specimen from the domestic commercial PWR reactor in hot cell are described.

  13. 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...

  14. Comparison of Instrumented Impact Standard and Testing Technology between Multiaxial Impact and Charpy Impact%仪器化多轴冲击和简支梁冲击标准与试验技术的比较

    Institute of Scientific and Technical Information of China (English)

    戴婷

    2015-01-01

    分析比较了仪器化多轴冲击标准ISO 6603-2和简支梁冲击标准ISO 179-2的异同,着重讨论了这些标准在测试技术上的不同要求,探讨了试验机性能对试验结果的影响,并提出了对试验机测控系统软硬件设计的技术要求.提出实验人员要了解不同类型冲击试验标准的差异,在实际测试过程中根据具体测试目的选择合适的试验方法;测试数据的精确度、曲线的质量保障和测试标准有关,还和试验机的性能有关,要求实验人员熟知试验机的核心技术参数,同时了解所选测试标准对试验机的要求,选择满足测试需求的试验机.

  15. Method for Estimating Percent Shear Fracture Appearance of Charpy-V Specimen of Nuclear Pressure Vessel Steel%核压力容器钢冲击断口剪切面积百分比的估算方法

    Institute of Scientific and Technical Information of China (English)

    伍晓勇; 冯明全; 崔永海

    2001-01-01

    Percent shear fracture appearance is an important factor to evaluate neutron irradiation embrittlement of nuclear pressure vessel steel.But it is difficult to measure the irregular surface directly,especially for post-irradiation speciments.Depending on Charpy-V instrumented impact tests,characteristic load values can be determined according to load-deflection curve which completely represents the impact failure processes,and percent shear fracture appearance can be estimated using different formula.The estimating method is more effective to calculate irradiation-induced changes in transition temperature,which already successfully applied to the irradiation surveillance test of reactor pressure vessel steel of Daya-bay nuclear power station.%在核压力容器钢的中子辐照脆化评价中,断口剪切面积百分比是一个重要的参数。但此参数不易直接测量,对于辐照后的放射性试样其测量更加困难。本文采用 Charpy-V示波冲击试验,并根据计算机采集得到的完整记录冲击过程的载荷 -位移曲线,即可确定相应的载荷特征值,同时估算出断口剪切面积百分比。该估算方法用于计算核压力容器钢因中子辐照引起的脆性转变温度的变化值,其计算结果较为准确且计算方法也简便,现已成功地应用于大亚湾核电站压力容器的辐照监督试验。

  16. Impact properties of the aircraft cast aluminium alloy Al-7Si0.6Mg (A357

    Directory of Open Access Journals (Sweden)

    Alexopoulos N.D.

    2010-06-01

    Full Text Available The impact mechanical properties of the widely used in the aeronautics A357 cast aluminum alloy were investigated by exploiting experiments on an instrumented Charpy impact testing machine. The evaluated impact properties for 25 different artificial aging heat treatment conditions were analyzed and discussed in conjunction with the respective tensile properties. Correlations are proposed to establish useful relationships between impact resistance and tensile strain energy density properties. The established correlations, which are well supported by the performed experiments, can be used to estimate the tensile ductility and toughness of the A357 cast aluminum alloy from the Charpy impact test. Performed fractographic analyses were supporting the physically arbitrary correlation between tensile strain energy density and impact resistance.

  17. Impact properties of the aircraft cast aluminium alloy Al-7Si0.6Mg (A357)

    Science.gov (United States)

    Alexopoulos, N. D.

    2010-06-01

    The impact mechanical properties of the widely used in the aeronautics A357 cast aluminum alloy were investigated by exploiting experiments on an instrumented Charpy impact testing machine. The evaluated impact properties for 25 different artificial aging heat treatment conditions were analyzed and discussed in conjunction with the respective tensile properties. Correlations are proposed to establish useful relationships between impact resistance and tensile strain energy density properties. The established correlations, which are well supported by the performed experiments, can be used to estimate the tensile ductility and toughness of the A357 cast aluminum alloy from the Charpy impact test. Performed fractographic analyses were supporting the physically arbitrary correlation between tensile strain energy density and impact resistance.

  18. Determinación de la tenacidad a la fractura de muestras de Acero 45 fundido, empleando las correlaciones entre el KIC y la energía de impacto medida en el ensayo de Charpy. // Determination of the fracture tenacity of cast Steel grade 45 samples, using th

    Directory of Open Access Journals (Sweden)

    F. Ramos Morales

    2005-05-01

    Full Text Available En el presente trabajo se determinan los valores de tenacidad a la fractura (KIC de muestras de Acero 45 fundido,empleando las correlaciones entre la tenacidad a la fractura y la energía de impacto (CVN obtenida del ensayo de Charpy.Se hace una discusión sobre las correlaciones que más se ajustan en la región de transición y en upper shelf. Se comparanlos valores obtenidos de estas correlaciones a valores de tenacidad a la fractura establecidos en la literatura.Palabras claves: Fractura, energía de impacto, acero fundido.______________________________________________________________________________Abstract.In this paper, the values of fracture toughness (KIC are determined on specimens of cast steel grade 45, using thecorrelations among the fracture toughness (KIC and the impact energy (CVN obtained from a Charpy test. A discussion ismade on the correlations that are better adjusted in the transition region and in upper shelf region. The obtained values arecompared from these correlations to values of fracture toughness (KIC settled down in the literature.Key words. Fracture, impact energy, cast steel.

  19. 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.

  20. 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)

  1. Irradiation programme MANITU: results of impact tests with the irradiated materials (2,4 dpa); Bestrahlungsprogramm MANITU. Ergebnisse der Kerbschlagbiegeversuche mit den bis 2,4 dpa bestrahlten Werkstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, H.C.; Dafferner, B.; Ries, H.; Romer, O.

    2001-05-01

    The irradiation project MANITU was planned and carried out in the frame of the European long-term fusion 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 reference specimens of MANITU a first tendency was recognizable. The mechanical properties of the newly developed low activation 7-10% Cr-W(Ge)VTa alloys are partly better compared to the modified commercial 10-11% Cr-NiMoVNb steels. After the evaluation of subsize Charpy tests with specimens irradiated up to 0.2 and 0.8 dpa in the first phase of the MANITU programme, better mechanical properties of the 7-10% Cr-W(Ge)VTa alloys were obvious. In the present report the results of instrumented impact tests within the second phase of the MANITU programme (irradiation dose 2.4 dpa, irradiation temperatures 250, 300, 350, 400, and 450 C) are analysed and assessed in comparison to the results of the irradiation up to 0.2 and 0.8 dpa in the first phase of the project. Among the examined alloys (MANET-I/II, K-Heat, OPTIFER-Ia/II, F82H, ORNL 3791) the ORNL steel shows the very best embrittlement behaviour after neutron irradiation. (orig.)

  2. 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

  3. The impact resistance of SiC and other mechanical properties of SiC and Si3N4

    Science.gov (United States)

    Bradt, R. C.

    1984-01-01

    Studies focused on the impact and mechanical behavior of SiC and Si3N4 at high temperatures are summarized. Instrumented Charpy impact testing is analyzed by a compliance method and related to strength; slow crack growth is related to processing, and creep is discussed. The transient nature of flaw populations during oxidation under load is emphasized for both SiC and Si3N4.

  4. RPSW/A摆锤示波冲击试验机测试系统改造%Modification to the Testing System of RPSW/A Pendulum Instrumented Charpy Impact Testing Machine

    Institute of Scientific and Technical Information of China (English)

    周海; 邵建龙; 方淑芳

    2006-01-01

    介绍了RPSW/A摆锤示波冲击试验机的基本组成、工作原理及存在的问题,提出了Windows平台下通过多功能PCI数据采集卡实现高速数据采集的设想.在此基础上用VB编写了数据采集及处理软件,使该试验机恢复正常,并解决了原机测试系统存在的故障率高、试验数据不易保存、操作烦琐等不足.

  5. Instrumentação de um pendulo para ensaio de impacto Charpy

    OpenAIRE

    1994-01-01

    Resumo: O ensaio de impacto Charpy convencional, possibilita que se determine a energia total ('E IND. T') absorvida para fratura de um corpo de prova entalhado, de dimensões padronizadas. Entretanto, sabe-se que essa energia total, resulta da soma de duas componentes: a energia necessária para iniciar a fratura ('E IND.I') mais a energia necessária para a propagação dessa fratura ('E IND. P'). No presente trabalho, é instrumentado um pêndulo de ensaio de impacto Charpy, utilizando-se técnica...

  6. A Repeated Impact Method and Instrument to Evaluate the Impact Fatigue Property of Drillpipe

    Science.gov (United States)

    Lin, Yuanhua; Li, Qiang; Sun, Yongxing; Zhu, Hongjun; Zhou, Ying; Xie, Juan; Shi, Taihe

    2013-04-01

    It is well known that drillpipe failures are a pendent problem in drilling engineering. Most of drillpipe failures are low amplitude-repeated impact fatigue failures. The traditional method is using Charpy impact test to describe the fracture property of drillpipe, but it cannot veritably characterize the impact fatigue property of drillpipe under low amplitude-repeated impact. Based on the Charpy impact and other methods, a repeated impact method and instrument have been proposed to simulate the low amplitude-repeated impact of downhole conditions for drillpipe. Then, a series of tests have been performed using this instrument. Test results demonstrate the drillpipe upset transition area nonhomogeneity is more severe than drillpipe body, which is the key factor that leads to washout and fracture frequently of it. As the one time impact energy increases, the repeated impact times decrease exponentially, therefore, the rotational speed has a great effect on the fatigue life of drillpipe, and it is vital to select a suitable rotational speed for drilling jobs. In addition, based on SEM fractographs we found that the fracture surface of repeated impact is similar to the fatigue fracture, and there are many low cycle fatigue characteristic features on fracture surface that reveal very good agreement with the features of drillpipe fatigue failures in the field.

  7. Impact resistance and fractography of low-alloy martensitic steels

    Directory of Open Access Journals (Sweden)

    S. Frydman

    2008-03-01

    Full Text Available In this paper dynamic properties of HTK SOOH, HTK 900H. Hardox 400 and Hardox 500 steeZs in delivcrcd stalc (aftcr hardening andtempering are considered. Charpy V - notch (CVN test rcsults in connection with fractography in the ductilc - to - brittle transitionternpcrature region were analyzed. The impact transition curve obtained from CVN tcst not always predicts properly a behavior ofmaterials in conditions of dynamic loading, so the analyze of character of fracture helps to evalitate the rcal bchavior of ma~crials. Tcstcdsamples were cut out longitudinally and transversely in relation to cold work direction. The results of CVN test far investigated steels, inthe range of temperatures from 40t o 20 "C are presented. Regarding ductilc - to - bri~tlel ransition temperature, there is a significantdiffcrcnce taking into account vatues of Charpy V cncrgy absorbcd and a character of fracture.

  8. 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.

  9. 16 CFR 1203.17 - Impact attenuation test.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Impact attenuation test. 1203.17 Section... SAFETY STANDARD FOR BICYCLE HELMETS The Standard § 1203.17 Impact attenuation test. (a) Impact test... the acceleration of the test headform during impact. Acceleration is measured with a...

  10. Antenna Pattern Impact on MIMO OTA Testing

    DEFF Research Database (Denmark)

    Fan, Wei; Nielsen, Jesper Ødum; Franek, Ondrej

    2013-01-01

    This paper investigates the impact of the DUT antenna pattern on the test area performance for multi-probe based MIMO OTA setup in terms of received voltage and spatial correlation. The plane wave synthesis (PWS) technique has been proposed for vertical polarization in the literature, where...... the goal is to approximate plane waves with arbitrary directions. The received voltage at the antenna terminal depends on the antenna radiation pattern and the impinging plane waves. A novel closed form technique to reproduce the received voltage with arbitrary incoming plane waves based on trigonometric...... interpolation is presented. The proposed technique provides a closed form solution for the PWS when the probe ring radius is infinite. The proposed technique shows that the impact of the antenna pattern on the induced received voltage accuracy is ruled by Nyquist sampling theory. Furthermore, the impact...

  11. 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.

  12. 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... REGULATIONS SAFETY STANDARD FOR BICYCLE HELMETS The Standard § 1203.11 Marking the impact test line. Prior to testing, the impact test line shall be determined for each helmet in the following manner. (a)...

  13. Effect of waveform graph of instrumented Charpy impact test on fracture mode with QT400-18L at low temperature%含镍QT400-18L低温断裂方式的分析

    Institute of Scientific and Technical Information of China (English)

    路焱

    2010-01-01

    示波冲击试验可以记录试样在断裂过程中载荷与冲击吸收功的完整信息,反映试样在承受冲击过程时载荷与时间的变化规律.使用示波冲击试验机测试了含镍QT400-18L试样低温环境下的冲击韧性,记录不同含镍量的球铁试样-40℃低温下的裂纹形成功与裂纹扩展功以及冲击载荷与时间的波形图.研究结果表明,不同含镍量QT400-18L试样发生不同形式的断裂,其中,镍的质量分数为0.70%的试样发生弹性变形的过程最长,弹性变形所需能量的消耗最大,断裂方式为韧性、脆性的混合型断裂,因此其低温冲击韧性最大,αkv可达到20.87 J/cm2.

  14. Factors affecting miniature Izod impact strength of tungsten-fiber-metal-matrix

    Science.gov (United States)

    Winsa, E. A.; Petrasek, D. W.

    1973-01-01

    The miniature Izod and Charpy impact strengths of copper, copper-nickel, and nickel-base superalloy uniaxially reinforced with continuous tungsten fibers were studied. In most cases, impact strength was increased by increasing fiber or matrix toughness, decreasing fibermatrix reaction, increasing test temperature, hot working, or heat treating. Notch sensitivity was reduced by increasing fiber content or matrix toughness. An equation relating impact strength to fiber and matrix properties and fiber content was developed. Program results imply that tungsten alloy-fiber/superalloy matrix composites can be made with adequate impact resistance for turbine blade or vane applications.

  15. Simulation of the drop impact test for moulded thermoplastic containers

    NARCIS (Netherlands)

    Reed, P.E.; Breedveld, G.; Lim, B.C.

    2000-01-01

    An analysis is made of the drop impact test for moulded plastics containers, as a first step towards the simulation of the impact event for design and development purposes. Experimental data are analysed from instrumented base drop impact testing of water-filled blow-moulded bottles, 20 and 210 l dr

  16. 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.)

  17. Genetic Testing for Breast Cancer: Psychological and Social Impact

    Science.gov (United States)

    Genetic testing for breast cancer: Psychological and social impact Genetic testing to estimate breast and ovarian cancer risk may prompt many emotional and psychological reactions. How will getting the news that you' ...

  18. Negative Impacts of High-Stakes Testing

    Science.gov (United States)

    Minarechová, Michaela

    2012-01-01

    High-stakes testing is not a new phenomenon in education. It has become part of the education system in many countries. These tests affect the school systems, teachers, students, politicians and parents, whether that is in a positive or negative sense. High-stakes testing is associated with concepts such as a school's accountability, funding…

  19. Negative Impacts of High-Stakes Testing

    Science.gov (United States)

    Minarechová, Michaela

    2012-01-01

    High-stakes testing is not a new phenomenon in education. It has become part of the education system in many countries. These tests affect the school systems, teachers, students, politicians and parents, whether that is in a positive or negative sense. High-stakes testing is associated with concepts such as a school's accountability, funding and…

  20. 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 sys......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....

  1. Particle impact tests. [simulation of micrometeoroid damage to orbiter surface

    Science.gov (United States)

    Komatsu, G. K.

    1978-01-01

    Particle impact tests were performed on three types of orbiter surface with a micrometeoroid facility. The test equipment electrostatically accelerated micron sized particles to high velocities simulating micrometeoroid impacts. Test particles were titanium diboride with typical velocities in the range 1 to 2.3 km x sec/1 and equivalent particle diameters in the range 4 to 16 microns. Impact angles to the material surface were 90, 60 and 30 degrees. The particle impact sites were located on the sample surfaces and craters were photographed with a magnification of 400X.

  2. 16 CFR Figure 9 to Part 1203 - Impact Test Apparatus

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Impact Test Apparatus 9 Figure 9 to Part 1203 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR BICYCLE HELMETS Pt. 1203, Fig. 9 Figure 9 to Part 1203—Impact Test Apparatus...

  3. Impact Testing for Materials Science at NASA - MSFC

    Science.gov (United States)

    Sikapizye, Mitch

    2010-01-01

    The Impact Testing Facility (ITF) at NASA - Marshall Space Flight Center is host to different types of guns used to study the effects of high velocity impacts. The testing facility has been and continues to be utilized for all NASA missions where impact testing is essential. The Facility has also performed tests for the Department of Defense, other corporations, as well as universities across the nation. Current capabilities provided by Marshall include ballistic guns, light gas guns, exploding wire gun, and the Hydrometeor Impact Gun. A new plasma gun has also been developed which would be able to propel particles at velocities of 20km/s. This report includes some of the guns used for impact testing at NASA Marshall and their capabilities.

  4. Subtask 12F4: Effects of neutron irradiation on the impact properties and fracture behavior of vanadium-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Loomis, B.A.; Smith, D.L. [Argonne National Lab., IL (United States)

    1995-03-01

    Up-to-date results on the effects of neutron irradiation on the impact properties and fracture behavior of V, V-Ti, V-Cr-Ti and V-Ti-Si alloys are presented in this paper, with an emphasis on the behavior of the U.S. reference alloys V-4Cr-4Ti containing 500-1000 wppm Si. Database on impact energy and cluctile-brittle transition temperature (DBTT) has been established from Charpy impact tests of one-third-size specimens irradiated at 420{degrees}C-600{degrees}C up to {approx}50 dpa in lithium environment in fast fission reactors. To supplement the Charpy impact tests fracture behavior was also characterized by quantitative SEM fractography on miniature tensile and disk specimens that were irradiated to similar conditions and fractured at -196{degrees}C to 200{degrees}C by multiple bending. For similar irradiation conditions irradiation-induced increase in DBTT was influenced most significantly by Cr content, indicating that irradiation-induced clustering of Cr atoms takes place in high-Cr (Cr {ge} 7 wt.%) alloys. When combined contents of Cr and Ti were {le}10 wt.%, effects of neutron irradiation on impact properties and fracture behavior were negligible. For example, from the Charpy-impact and multiple-bend tests there was no indication of irradiation-induced embrittlement for V-5Ti, V-3Ti-1Si and the U.S. reference alloy V-4Cr-4Ti after irradiation to {approx}34 dpa at 420{degrees}C to 600{degrees}C, and only ductile fracture was observed for temperatures as low as -196{degrees}C. 14 refs., 8 figs., 1 tab.

  5. Light-weight radioisotope heater unit (LWRHU) impact tests

    Science.gov (United States)

    Reimus, M. A. H.; Rinehart, G. H.; Herrera, A.; Lopez, B.; Lynch, C.; Moniz, P.

    1998-01-01

    The light-weight radioisotope heater unit (LWRHU) is a 238PuO2-fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. Los Alamos National Laboratory designed, fabricated, and safety tested the LWRHU. The heat source consists of a hot-pressed 238PuO2 fuel pellet, a Pt-30Rh vented capsule, a pyrolytic graphite insulator, and a fineweave-pierced fabric graphite aeroshell assembly. To compare the performance of the LWRHUs fabricated for the Cassini mission with the performance of those fabricated for the Galileo mission, and to determine a failure threshold, two types of impact tests were conducted. A post-reentry impact test was performed on one of 180 flight-quality units produced for the Cassini mission and a series of sequential impact tests using simulant-fueled LWRHU capsules were conducted respectively. The results showed that deformation and fuel containment of the impacted Cassini LWRHU was similar to that of a previously tested Galileo LWRHU. Both units sustained minimal deformation of the aeroshell and fueled capsule; the fuel was entirely contained by the platinum capsule. Sequential impacting, in both end-on and side-on orientations, resulted in increased damage with each subsequent impact. Sequential impacting of the LWRHU appears to result in slightly greater damage than a single impact at the final impact velocity of 50 m/s.

  6. Comparative Testing for Corporate Impact Assessment Tools

    DEFF Research Database (Denmark)

    Farsang, Andrea; Reisch, Lucia A.

    Environmental and social pressures have increased substantially over the few last decades, and have been accompanied by growing political pressure (e.g., mandatory economic, environmental, social, and governance reporting) and respective societal demands (e.g., critical media reports). Companies...... are increasingly challenged to be ready to respond to these demands. This paper critically examines the following question: To what extent do the measurement tools currently available, in practice and in literature, effectively measure companies’ impact on sustainable development goals (SDGs)? The focus issues...... of our study are: poverty, water and sanitation, education, food and agriculture, climate change, and human rights in three industries, namely: footwear, coffee, and paper and pulp. The paper develops a protocol for the selection and quantification of indicators that can be used in selecting...

  7. Impact Toughness of an Isothermally Treated Zeron®100 SDSS

    Science.gov (United States)

    Calliari, Irene; Breda, Marco; Ramous, Emilio; Brunelli, Katya; Pizzo, Marco; Menapace, Cinzia

    2012-10-01

    The aim of the present study is to investigate the impact toughness of a UNS 32760 SDSS, in relation to the quantity of secondary phases precipitated after isothermal aging in the range of 850-950 °C and for different exposure times. The impact toughness has been investigated by means of instrumented impact testing, using Charpy V-notched specimens at room temperature. The impact testing results show that, for an amount of about 0.5% volume fraction of intermetallic phase, the impact toughness is reduced by over 50%. For volume fractions higher than 1.5-2%, the impact toughness is definitively compromised, and small entities of plastic deformations are enough to cause a prevailing brittle fracture mechanism. By increasing the precipitates' amounts, the fracture mechanism shows an ever more prominent brittle behavior until 6% volume fraction, exceeding which the ductile component is totally absent.

  8. 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.

  9. Using Baseline Studies in the Investigation of Test Impact

    Science.gov (United States)

    Wall, Dianne; Horak, Tania

    2007-01-01

    The purpose of this article is to discuss the role of "baseline studies" in investigations of test impact and to illustrate the type of thinking underlying the design and implementation of such studies by reference to a recent study relating to a high-stakes test of English language proficiency. Baseline studies are used to describe an educational…

  10. 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

  11. Evaluation of dynamic fracture toughness for Yong Gwang unit 5 reactor pressure vessel materials (Baseline Tests)

    Energy Technology Data Exchange (ETDEWEB)

    Chi Se Hwan; Kim, Joo Hag; Hong, Jun Hwa; Kwon, Sun Chil; Lee, Bong Sang [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-10-01

    The dynamic fracture toughness (K{sub d}) of intermediate shell and its weld in SA 508 CI. 3 Yong Gwang 5 reactor pressure vessel was determined and evaluated. Precracked thirty six Charpy specimens were tested by using an instrumented impact tester. The purpose of present work is to evaluate and confirm the un-irradiated dynamic fracture toughness and to provide pre-irradiation baseline data for future evaluation on dynamic fracture toughness change during operation. 18 refs., 5 figs., 5 tabs. (Author)

  12. 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.

  13. Irradiation programme MANITU. Results of impact tests with the irradiated materials of the second irradiation phase (0.8 dpa); Bestrahlungsprogramm MANITU. Ergebnisse der Kerbschlagbiegeversuche mit den bis 0,8 dpa bestrahlten Werkstoffen der zweiten Bestrahlungsphase

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, H.C.; Rieth, M.; Dafferner, B.; Ries, H.; Romer, O.

    2000-09-01

    The irradiation project MANITU was planned and carried out in the frame of the European Longterm Fusion 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 reference specimens of MANITU a first tendency was recognizable. The mechanical properties of the newly developed low activation 7-10% Cr-W(Ge)VTa alloys are partly better compared to the modified commercial 10-11% Cr-NiMoVNb steels. After the evaluation of subsize Charpy tests with specimens irradiated up to 0.2 and 0.8 dpa in the first phase of the MANITU programme, better mechanical properties of the 7-10% Cr-W(Ge)VTa alloys were obvious. In the present report the results of instrumented impact tests within the second phase of the MANITU programme (irradiation dose 0.8 dpa, irradiation temperatures 250, 300, 350, 400, and 450 C) are analysed and assessed in comparison to the results of the irradiation up to 0.8 dpa in the first phase of the project. Among the examined alloys (OPTIMAR, OPTIFER-IV, GA3X) the GA3X steel shows the very best embrittlement behaviour after neutron irradiation. (orig.) [German] Das Bestrahlungsprojekt MANITU wurde im Rahmen des europaeischen Langzeitprogramms fuer Materialentwicklung fuer die Kernfusion geplant und durchgefuehrt. Das Problem der bestrahlungsinduzierten Versproedung bei den in Frage kommenden martensitischen Werkstoffen ist nach wie vor ungeloest. Eine erste Tendenz zeichnete sich jedoch nach der Auswertung der Kerbschlagbiegeversuche an den unbestrahlten miniaturisierten Referenzproben des MANITU-Programms ab. Die neu entwickelten niedrig aktivierbaren 7-10% Cr-W(Ge)VTa-Legierungen weisen gegenueber den modifizierten kommerziellen 10-11% Cr-NiMoVNb-Staehlen teilweise bessere mechanische Eigenschaften auf. Nach Auswertung der Kerbschlagbiegeversuche an den in der ersten Phase des MANITU-Programms mit 0

  14. 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…

  15. Visualizing the impact of prevalence on a diagnostic test

    DEFF Research Database (Denmark)

    Rehling, Michael

    2010-01-01

    The purpose of a diagnostic test is to confirm or rule out disease or to increase or decrease the probability of disease. Only a few tests can separate all patients into those with and without a disease (true positive and true negative test). Usually there will be some false test results (false...... 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....

  16. Irradiation programme HFR phase 1b. Results of impact tests with the irradiated materials (2.4 dpa); Bestrahlungsprogramm HFR Phase 1b. Ergebnisse der Kerbschlagbiegeversuche mit den bis 2,4 dpa bestrahlten Werkstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, H.C.; Dafferner, B.; Ries, H.; Lautensack, S.; Romer, O.

    2004-04-01

    The irradiation project HFR phase 1b was planned and carried out in the frame of the European Long-term Fusion Materials Development Programme. It represents the continuation of the former High-Flux-Reactor irradiation programmes which are documented in detail in former FZK-reports. The problem of the irradiation induced embrittlement of possible martensitic alloy candidates is still not finally solved. After evaluation of sub-size Charpy tests with the 2.4 dpa irradiated specimens, the low activation 7-10%-Cr-W(Ge)VTa alloys showed outstandingly better characteristics compared to the modified commercial 10-11%-Cr-NiMoVNb steels. The emphasis of the phase 1b project is now on the investigation of low activating OPTIFER-alloys, which exhibit in contrast to the previously irradiated OPTIFER-steels a clearly reduced boron content in order to reduce the irradiation embrittlement. In the present report the results of instrumented impact tests within the phase 1b programme (irradiation dose 2.4 dpa, irradiation temperatures 250, 300, 350, 400, and 450 C) are analysed and assessed in comparison to the results of the MANITU- and HFR phase 1a- irradiation programmes. Herein, the OPTIFER-V steel, which is nearly identical to the industrial heat EUROFER97 (which became available after the irradiation), supplied the best results. (orig.)

  17. Hypervelocity Impact Test Results for a Metallic Thermal Protection System

    Science.gov (United States)

    Karr, Katherine L.; Poteet, Carl C.; Blosser, Max L.

    2003-01-01

    Hypervelocity impact tests have been performed on specimens representing metallic thermal protection systems (TPS) developed at NASA Langley Research Center for use on next-generation reusable launch vehicles (RLV). The majority of the specimens tested consists of a foil gauge exterior honeycomb panel, composed of either Inconel 617 or Ti-6Al-4V, backed with 2.0 in. of fibrous insulation and a final Ti-6Al-4V foil layer. Other tested specimens include titanium multi-wall sandwich coupons as well as TPS using a second honeycomb sandwich in place of the foil backing. Hypervelocity impact tests were performed at the NASA Marshall Space Flight Center Orbital Debris Simulation Facility. An improved test fixture was designed and fabricated to hold specimens firmly in place during impact. Projectile diameter, honeycomb sandwich material, honeycomb sandwich facesheet thickness, and honeycomb core cell size were examined to determine the influence of TPS configuration on the level of protection provided to the substructure (crew, cabin, fuel tank, etc.) against micrometeoroid or orbit debris impacts. Pictures and descriptions of the damage to each specimen are included.

  18. End-on radioisotope thermoelectric generator impact tests

    Energy Technology Data Exchange (ETDEWEB)

    Reimus, M.A.H.; Hhinckley, J.E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of [sup 238]Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  19. End-on radioisotope thermoelectric generator impact tests

    Science.gov (United States)

    Reimus, M. A. H.; Hinckley, J. E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  20. Toughness testing and high-temperature oxidation evaluations of advanced alloys for core internals

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chen, Xiang [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-16

    Alloy X-750 was procured from Carpenter Technology and Bodycote in this year. An appropriate TMT was developed on Alloy 439 to obtain materials with refined grain size for property screening tests. Charpy V-notch impact tests were completed for the three ferritic steels Grade 92, Alloy 439, and 14YWT. Fracture toughness tests at elevated temperatures were completed for 14YWT. The tests will be completed for the other alloys in next fiscal year. Steam oxidation tests of the three ferritic steels, 316L, and Zr–2.5Nb have been completed. The steam tests of the Ni-based superalloys and the other austenitic stainless steels will be continued and finished in next fiscal year. Performance ranking in terms of steam oxidation resistance and impact/fracture toughness of the alloys will be deduced.

  1. Toughness testing and high-temperature oxidation evaluations of advanced alloys for core internals

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pint, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Chen, Xiang [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-16

    In summary, Alloy X-750 was procured from Carpenter Technology and Bodycote in this year. An appropriate TMT was developed on Alloy 439 to obtain materials with refined grain size for property screening tests. Charpy V-notch impact tests were completed for the three ferritic steels Grade 92, Alloy 439, and 14YWT. Fracture toughness tests at elevated temperatures were completed for 14YWT. The tests will be completed for the other alloys in next fiscal year. Steam oxidation tests of the three ferritic steels, 316L, and Zr–2.5Nb have been completed. The steam tests of the Ni-based superalloys and the other austenitic stainless steels will be continued and finished in next fiscal year. Performance ranking in terms of steam oxidation resistance and impact/fracture toughness of the alloys will be deduced.

  2. 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.

  3. Hydrodynamic impact analysis and testing of an unmanned aerial vehicle

    Science.gov (United States)

    Bird, Isabel

    Analysis and testing have been conducted to assess the feasibility of a small UAV that can be landed in the water and recovered for continued use. Water landings may be desirable in a number of situations, for example when testing UAVs outside of the territorial waters of the US to avoid violating FAA regulations. Water landings may also be desirable when conducting surveillance missions in marine environments. Although the goal in landing is to have the UAV lightly set down on the water, rough seas or gusty winds may result in a nose-in landing where the UAV essentially impacts the surface of the water. The tested UAV is a flying wing design constructed of expanded polypropylene foam wings with a hollowed out center-section for the avionics. Acceleration data was collected by means of LIS331 3-axis accelerometers positioned at five locations, including the wingtips. This allowed conclusions to be drawn with respect to the loads experienced on impact throughout the airframe. This data was also used to find loads corresponding to the maximum decelerations experienced during impact. These loads were input into a finite element analysis model of the wing spars to determine stress in the wing spars. Upon impact, the airframe experienced high-frequency oscillation. Surprisingly, peak accelerations at the wingtips were observed at up to 15g greater than corresponding accelerations at the center of the fuselage.

  4. Impact Resistance of Short Fibre/Particle Reinforced Epoxy

    Science.gov (United States)

    Chang, L.; Zhang, Z.; Breidt, C.

    2004-01-01

    The influence of temperature on the fracture behaviour of epoxy-based composites was studied using an instrumented Charpy impact approach. A series of epoxy reinforced with short carbon fibres (SCF) and additionally filled with various amounts of PTFE and graphite particles was considered in this study. Unnotched specimens were tested at -196°C, 20°C, and 70°C, respectively. It was found that, for specimens with the same matrix content, a proper hybridisation of composites was possible to achieve a better impact performance compared to single-filler/epoxy. For example, 10 vol.%PTFE+10 vol.%SCF/epoxy exhibited a higher impact resistance than that of 20 vol.%SCF/epoxy at all measured temperatures. Failure mechanisms at different temperatures were discussed with SEM fractography.

  5. The ethics of testing a test: randomized trials of the health impact of diagnostic tests for infectious diseases.

    Science.gov (United States)

    Dowdy, David W; Gounder, Celine R; Corbett, Elizabeth L; Ngwira, Lucky G; Chaisson, Richard E; Merritt, Maria W

    2012-12-01

    In the last decade, many new rapid diagnostic tests for infectious diseases have been developed. In general, these new tests are developed with the intent to optimize feasibility and population health, not accuracy alone. However, unlike drugs or vaccines, diagnostic tests are evaluated and licensed on the basis of accuracy, not health impact (eg, reduced morbidity or mortality). Thus, these tests are sometimes recommended or scaled up for purposes of improving population health without randomized evidence that they do so. We highlight the importance of randomized trials to evaluate the health impact of novel diagnostics and note that such trials raise distinctive ethical challenges of equipoise, equity, and informed consent. We discuss the distinction between equipoise for patient-important outcomes versus diagnostic accuracy, the equity implications of evaluating health impact of diagnostics under routine conditions, and the importance of offering reasonable choices for informed consent in diagnostic trials.

  6. One-month test-retest reliability of the ImPACT test battery.

    Science.gov (United States)

    Schatz, Philip; Ferris, Charles S

    2013-08-01

    In order to better understand the test-retest reliability of the ImPACT test battery, 25 undergraduate students completed two ImPACT tests across a time frame of 4 weeks between assessments. Participants had not previously completed ImPACT and had no history of concussion. Pearson's correlation coefficients (r) and intraclass correlation coefficients (ICCs) were as follows: Verbal Memory = .66/.79 (r/ICC), Visual Memory = .43/.60, Visual Motor Speed = .78/.88, Reaction Time = .63/.77, and Total Symptoms = .75/.81. Dependent sample t-tests revealed significant improvement on only Visual Motor Speed composite scores. Reliable Change Indices showed a significant number of participants fell outside 80% and 95% confidence intervals for only Visual Motor Speed scores (but no other indices), whereas all scores were within 80% and 95% confidence intervals using regression-based measures. Results suggest that repeated exposure to the ImPACT test may result in significant improvements in the physical mechanics of how college students interact with the test (e.g., performance on Visual Motor Speed), but repeated exposure across 1 month does not result in practice effects in memory performance or reaction time.

  7. Applicability of the Modified Ritchie-Knott-Rice Failure Criterion to Examine the Feasibility of Miniaturized Charpy Type SE(B Specimens

    Directory of Open Access Journals (Sweden)

    Toshiyuki Meshii

    2016-01-01

    Full Text Available This paper examined whether the modified Ritchie-Knott-Rice (RKR failure criterion can be applied to examine the feasibility of miniaturized Charpy type SE(B specimens of thickness-to-width ratio B/W=1. The modified RKR failure criterion considered in this paper is the (4δt,σ22c criterion which predicts the onset of cleavage fracture when the midplane crack-opening stress measured at a distance equal to four times the crack-tip opening displacement, denoted as σ22d, exceeds a critical stress σ22c. Specimens with B values of 25, 10, 3, and 2 mm (denoted as 25t, 10t, 3t, and 2t specimens, resp. manufactured with 0.55% carbon steel were tested at 20°C. The results showed that the modified RKR criterion could appropriately predict the occurrence of cleavage fracture accompanied by negligibly small stable crack extension (denoted as KJc fracture naturally for the 25t and 10t specimens. The modified RKR criterion could also predict that KJc fracture does not occur for the 2t specimen. The σ22c obtained from specimens for the 25t and 10t specimens exhibited only a small difference, indicating that the Jc obtained from the 10t specimens can be used to predict the Jc that will be obtained with the 25t specimens.

  8. Radioisotope thermoelectric generator/thin fragment impact test

    Energy Technology Data Exchange (ETDEWEB)

    Reimus, M.A.H.; Hinckley, J.E.

    1998-12-31

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the convertor housing, failure of one fueled clad, and release of a small quantity of fuel.

  9. Radioisotope thermoelectric generator/thin fragment impact test

    Science.gov (United States)

    Reimus, M. A. H.; Hinckley, J. E.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  10. 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.

  11. Can clinical tests help monitor human papillomavirus vaccine impact?

    Science.gov (United States)

    Meites, Elissa; Lin, Carol; Unger, Elizabeth R; Steinau, Martin; Patel, Sonya; Markowitz, Lauri E; Hariri, Susan

    2013-09-01

    As immunization programs for human papillomavirus (HPV) are implemented more widely around the world, interest is increasing in measuring their impact. One early measurable impact of HPV vaccine is on the prevalence of specific HPV types in a population. In low-resource settings, a potentially attractive strategy would be to monitor HPV prevalence using clinical cervical cancer screening test results to triage specimens for HPV typing. We assessed this approach in a nationally representative population of U.S. females aged 14-59 years. Using self-collected cervico-vaginal swab specimens from 4,150 women participating in the National Health and Nutrition Examination Survey during 2003-2006, we evaluated type-specific HPV prevalence detected by the Roche linear array (LA) research test on all specimens, compared with type-specific HPV prevalence detected by LA conducted only on specimens positive by the digene hybrid capture 2 (HC-2) clinical test. We calculated weighted prevalence estimates and their 95% confidence intervals (CIs), and examined relative type-specific HPV prevalence according to the two testing approaches. The population prevalence of oncogenic HPV vaccine types 16/18 was 6.2% (CI:5.4-7.1) by LA if all specimens were tested, and 2.4% (CI:1.9-3.0) if restricted to positive HC-2. Relative prevalence of individual HPV types was similar for both approaches. Compared with typing all specimens, a triage approach would require testing fewer specimens, but a greater reduction in HPV prevalence or a larger group of specimens would be needed to detect vaccine impact. Further investigation is warranted to inform type-specific HPV monitoring approaches around the world.

  12. Arcjet Testing of Micro-Meteoroid Impacted Thermal Protection Materials

    Science.gov (United States)

    Agrawal, Parul; Munk, Michelle M.; Glaab, Louis J.

    2013-01-01

    There are several harsh space environments that could affect thermal protection systems and in turn pose risks to the atmospheric entry vehicles. These environments include micrometeoroid impact, extreme cold temperatures, and ionizing radiation during deep space cruise, all followed by atmospheric entry heating. To mitigate these risks, different thermal protection material samples were subjected to multiple tests, including hyper velocity impact, cold soak, irradiation, and arcjet testing, at various NASA facilities that simulated these environments. The materials included a variety of honeycomb packed ablative materials as well as carbon-based non-ablative thermal protection systems. The present paper describes the results of the multiple test campaign with a focus on arcjet testing of thermal protection materials. The tests showed promising results for ablative materials. However, the carbon-based non-ablative system presented some concerns regarding the potential risks to an entry vehicle. This study provides valuable information regarding the capability of various thermal protection materials to withstand harsh space environments, which is critical to sample return and planetary entry missions.

  13. 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.

  14. Shape Distribution of Fragments from Microsatellite Impact Tests

    Science.gov (United States)

    Liou, J.C.; Hanada, T.

    2009-01-01

    Fragment shape is an important factor for conducting reliable orbital debris damage assessments for critical space assets, such as the International Space Station. To date, seven microsatellite impact tests have been completed as part of an ongoing collaboration between Kyushu University and the NASA Orbital Debris Program Office. The target satellites ranged in size from 15 cm 15 cm 15 cm to 20 cm 20 cm 20 cm. Each target satellite was equipped with fully functional electronics, including circuits, battery, and transmitter. Solar panels and multi-layer insulation (MLI) were added to the target satellites of the last two tests. The impact tests were carried out with projectiles of different sizes and impact speeds. All fragments down to about 2 mm in size were collected and analyzed based on their three orthogonal dimensions, x, y, and z, where x is the longest dimension, y is the longest dimension in the plane perpendicular to x, and z is the longest dimension perpendicular to both x and y. Each fragment was also photographed and classified by shape and material composition. This data set serves as the basis of our effort to develop a fragment shape distribution. Two distinct groups can be observed in the x/y versus y/z distribution of the fragments. Objects in the first group typically have large x/y values. Many of them are needle-like objects originating from the fragmentation of carbon fiber reinforced plastic materials used to construct the satellites. Objects in the second group tend to have small x/y values, and many of them are box-like or plate-like objects, depending on their y/z values. Each group forms the corresponding peak in the x/y distribution. However, only one peak can be observed in the y/z distribution. These distributions and how they vary with size, material type, and impact parameters will be described in detail within the paper.

  15. Target Soil Impact Verification: Experimental Testing and Kayenta Constitutive Modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Broome, Scott Thomas [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Flint, Gregory Mark [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Dewers, Thomas [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Newell, Pania [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    This report details experimental testing and constitutive modeling of sandy soil deformation under quasi - static conditions. This is driven by the need to understand constitutive response of soil to target/component behavior upon impact . An experimental and constitutive modeling program was followed to determine elastic - plastic properties and a compressional failure envelope of dry soil . One hydrostatic, one unconfined compressive stress (UCS), nine axisymmetric compression (ACS) , and one uniaxial strain (US) test were conducted at room temperature . Elastic moduli, assuming isotropy, are determined from unload/reload loops and final unloading for all tests pre - failure and increase monotonically with mean stress. Very little modulus degradation was discernable from elastic results even when exposed to mean stresses above 200 MPa . The failure envelope and initial yield surface were determined from peak stresses and observed onset of plastic yielding from all test results. Soil elasto - plastic behavior is described using the Brannon et al. (2009) Kayenta constitutive model. As a validation exercise, the ACS - parameterized Kayenta model is used to predict response of the soil material under uniaxial strain loading. The resulting parameterized and validated Kayenta model is of high quality and suitable for modeling sandy soil deformation under a range of conditions, including that for impact prediction.

  16. 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.

  17. 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.

  18. Estimating the Impacts of Educational Interventions Using State Tests or Study-Administered Tests. NCEE 2012-4016

    Science.gov (United States)

    Olsen, Robert B.; Unlu, Fatih; Price, Cristofer; Jaciw, Andrew P.

    2011-01-01

    This report examines the differences in impact estimates and standard errors that arise when these are derived using state achievement tests only (as pre-tests and post-tests), study-administered tests only, or some combination of state- and study-administered tests. State tests may yield different evaluation results relative to a test that is…

  19. Low temperature impact strength of heavy section ductile iron castings: effects of microstructure and chemical composition

    Directory of Open Access Journals (Sweden)

    C. Labrecque

    2011-02-01

    Full Text Available A foundry research project has been recently initiated at RTIT in order to better understand the fabrication of as-cast heavy section DI parts meeting high impact energy requirements at low temperatures. The experimental castings have the following dimensions 180 mm x 180 mm x 190 mm. The achieved as-cast Charpy impact strengths were as follows: 17 J (RT, 16 J (-20°C and 11 J (-40°C. The foundry process, the chemical composition and the microstructure of this experimental casting are compared to the ones of various examples in order to show the detrimental effects of residual elements, microshrinkage and microcarbide on the impact properties. Finally, quality index empirical models (based on casting chemical compositions are used to analyse the impact tests results. This paper illustrates that an adequate nodule count can contribute to reducing the detrimental effects of the residual elements and microsegregation.

  20. An Assessment of Testing Requirement Impacts on Nuclear Thermal Propulsion Ground Test Facility Design

    Science.gov (United States)

    Shipers, Larry R.; Ottinger, Cathy A.; Sanchez, Lawrence C.

    1994-07-01

    Programs to develop solid core nuclear thermal propulsion (NTP) systems have been under way at the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA), and the Department of Energy (DOE). These programs have recognized the need for a new ground test facility to support development of NTP systems. However, the different military and civilian applications have led to different ground test facility requirements. The Department of Energy (DOE) in its role as landlord and operator of the proposed research reactor test facilities has initiated an effort to explore opportunities for a common ground test facility to meet both DoD and NASA needs. The baseline design and operating limits of the proposed DoD NTP ground test facility are described. The NASA ground test facility requirements are reviewed and their potential impact on the DoD facility baseline is discussed.

  1. An assessment of testing requirement impacts on nuclear thermal propulsion ground test facility design

    Energy Technology Data Exchange (ETDEWEB)

    Shipers, L.R.; Ottinger, C.A.; Sanchez, L.C.

    1993-10-25

    Programs to develop solid core nuclear thermal propulsion (NTP) systems have been under way at the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA), and the Department of Energy (DOE). These programs have recognized the need for a new ground test facility to support development of NTP systems. However, the different military and civilian applications have led to different ground test facility requirements. The Department of Energy (DOE) in its role as landlord and operator of the proposed research reactor test facilities has initiated an effort to explore opportunities for a common ground test facility to meet both DoD and NASA needs. The baseline design and operating limits of the proposed DoD NTP ground test facility are described. The NASA ground test facility requirements are reviewed and their potential impact on the DoD facility baseline is discussed.

  2. The impact of toxicity testing costs on nanomaterial regulation.

    Science.gov (United States)

    Choi, Jae-Young; Ramachandran, Gurumurthy; Kandlikar, Milind

    2009-05-01

    Information about the toxicity of nanoparticles is important in determining how nanoparticles will be regulated. In the U.S., the burden of collecting this information and conducting risk assessment is placed on regulatory agencies without the budgetary means to carry out this mandate. In this paper, we analyze the impact of testing costs on society's ability to gather information about nanoparticle toxicity and whether such costs can reasonably be borne by an emerging industry. We show for the United States that costs for testing existing nanoparticles ranges from $249 million for optimistic assumptions about nanoparticle hazards (i.e., they are primarily safe and mainly require simpler screening assays) to $1.18 billion for a more comprehensive precautionary approach (i.e., all nanomaterials require long-term in vivo testing). At midlevel estimates of total corporate R&D spending, and assuming plausible levels of spending on hazard testing, the time taken to complete testing is likely to be very high (34-53 years) if all existing nanomaterials are to be thoroughly tested. These delays will only increase with time as new nanomaterials are introduced. The delays are considerably less if less-stringent yet risk-averse perspectives are used. Our results support a tiered risk-assessment strategy similar to the EU's REACH legislation for regulating toxic chemicals.

  3. 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...

  4. Manganese steel in impact wear testing; Manganhartstahl in Stossverschleisstest

    Energy Technology Data Exchange (ETDEWEB)

    Patzelt, B.; Hemmann, U.; Deters, L. [Magdeburg Univ. (Germany). Inst. fuer Maschinenkonstruktion

    2000-12-01

    Beating arms in impact crushers show high wear. In order to simulate the process of the mainly occuring impact wear, experimental investigations with a special test device were carried out. With this 11 different charges of manganese steel differing in their chemical composition were tested. The different chemical composition of the charges led to different results concerning the wear resistance. A significant interrelationship between wear resistance and macro-hardness of the charges of the manganese steel could be detected. With a faster rotor speed a considerable increase of wear could be determined as well. Microscopical investigations on worn test pieces exhibit a typical embedding of small particles of concrete into the metal matrix. (orig.) [German] Die Schlagleisten in Prallbrechern unterliegen einen hohen Verschleiss. Um den Prozess des hauptsaechlich auftretenden Stossverschleisses zu simulieren, wurden Modelluntersuchungen mit einer speziellen Pruefeinrichtung durchgefuehrt. Dabei konnten 11 verschiedene Chargen von Manganhartstahl, die sich im wesentlichen in ihrer chemischen Zusammensetzung unterschieden, untersucht werden. Die unterschiedliche chemische Zusammensetzung der einzelnen Chargen fuehrte zu unterschiedlichen Ergebnissen hinsichtlich der Verschleissbestaendigkeit der einzelnen Modellschlagleisten. Hierbei ist ein signifikanter Zusammenhang zwischen der Verschleissbestaendigkeit und der Makrohaerte der Manganhartstaehle zu erkennen. Die Umfangsgeschwindigkeit des Rotors der Pruefeinrichtung beeinflusst ebenfalls das Verschleissverhalten, und zwar fuehrte eine hoehere Umfangsgeschwindigkeit zu hoeherem Verschleiss. Mikroskopische Untersuchungen an geschaedigten Probekoerpern zeigten ein Einbetten von kleinsten Partikeln aus Beton im oberflaechennahen Stoffbereich der Metallmatrix. (orig.)

  5. Impact strength of denture polymethyl methacrylate reinforced with continuous glass fibers or metal wire.

    Science.gov (United States)

    Vallittu, P K; Vojtkova, H; Lassila, V P

    1995-12-01

    The impact strength of heat-cured acrylic resin test specimens that had been reinforced in various ways was compared in this study. Ten rectangular test specimens were fabricated for each test group. The strengtheners included 1.0-mm-diameter steel wire and continuous E-glass fibers. Both notched and unnotched test specimens were tested in a Charpy-type impact test. In a further analysis the concentration of glass fibers in the test specimens was determined and plotted against the impact strength of the test specimens. The results showed that, compared with the unreinforced specimens, both types of reinforcement increased the impact strength of the test specimens considerably (p < 0.001). There was no clear difference between the mean impact strength value of the test specimens reinforced with metal wire and that of the specimens reinforced with glass fiber. The correlation coefficient between the fiber concentration of the test specimens and their impact strength was 0.818 (p < 0.005). Specimens with fiber concentrations greater than 25 wt% yielded to the higher impact strength more readily than those with metal wire reinforcement did.

  6. Model calibration and validation of an impact test simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hemez, F. M. (François M.); Wilson, A. C. (Amanda C.); Havrilla, G. N. (George N.)

    2001-01-01

    This paper illustrates the methodology being developed at Los Alamos National Laboratory for the validation of numerical simulations for engineering structural dynamics. The application involves the transmission of a shock wave through an assembly that consists of a steel cylinder and a layer of elastomeric (hyper-foam) material. The assembly is mounted on an impact table to generate the shock wave. The input acceleration and three output accelerations are measured. The main objective of the experiment is to develop a finite element representation of the system capable of reproducing the test data with acceptable accuracy. Foam layers of various thicknesses and several drop heights are considered during impact testing. Each experiment is replicated several times to estimate the experimental variability. Instead of focusing on the calibration of input parameters for a single configuration, the numerical model is validated for its ability to predict the response of three different configurations (various combinations of foam thickness and drop height). Design of Experiments is implemented to perform parametric and statistical variance studies. Surrogate models are developed to replace the computationally expensive numerical simulation. Variables of the finite element model are separated into calibration variables and control variables, The models are calibrated to provide numerical simulations that correctly reproduce the statistical variation of the test configurations. The calibration step also provides inference for the parameters of a high strain-rate dependent material model of the hyper-foam. After calibration, the validity of the numerical simulation is assessed through its ability to predict the response of a fourth test setup.

  7. Characterization of ductile-brittle transition behavior in Mn-Mo-Ni low alloy steels for reactor pressure vessel by small punch test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. C.; Lee, B. S.; Park, S. D.; Kim, K. B

    2004-12-01

    Small Punch (SP) tests were performed to evaluate the ductile-brittle transition behavior of Reactor Pressure Vessel (RPV) steels produced by different manufacturing (refining) processes. The results were compared to the standard test results, such as the conventional Charpy impact tests, JIC test and the Master Curve fracture toughness tests in accordance with the ASTM standard E1921. The SP transition temperatures (TSP), which are determined by the middle of the upper SP energy, showed a good correlation with the Charpy index temperatures. And the critical fracture strength, {sigma}{sup *}{sub f(sp)} from small punch test were found to have a linear relationship to the values from the pre-cracked specimens({sigma}{sup *}{sub f(PCVN)}). From the observation of thickness changes according to displacement, Equivalent strain(Eq) could be obtained as a function of ball displacement. It is found that relation between specimen thickness and ball displacement is not dependent on material properties and it is expressed as a function of ball displacement, and then SP equivalent strain(Eq) have close relationship with the fracture toughness(J{sub IC})

  8. Experimental impact testing and analysis of composite fan cases

    Science.gov (United States)

    Vander Klok, Andrew Joe

    For aircraft engine certification, one of the requirements is to demonstrate the ability of the engine to withstand a fan blade-out (FBO) event. A FBO event may be caused by fatigue failure of the fan blade itself or by impact damage of foreign objects such as bird strike. An un-contained blade can damage flight critical engine components or even the fuselage. The design of a containment structure is related to numerous parameters such as the blade tip speed; blade material, size and shape; hub/tip diameter; fan case material, configuration, rigidity, etc. To investigate all parameters by spin experiments with a full size rotor assembly can be prohibitively expensive. Gas gun experiments can generate useful data for the design of engine containment cases at much lower costs. To replicate the damage modes similar to that on a fan case in FBO testing, the gas gun experiment has to be carefully designed. To investigate the experimental procedure and data acquisition techniques for FBO test, a low cost, small spin rig was first constructed. FBO tests were carried out with the small rig. The observed blade-to-fan case interactions were similar to those reported using larger spin rigs. The small rig has the potential in a variety of applications from investigating FBO events, verifying concept designs of rotors, to developing spin testing techniques. This rig was used in the developments of the notched blade releasing mechanism, a wire trigger method for synchronized data acquisition, high speed video imaging and etc. A relationship between the notch depth and the release speed was developed and verified. Next, an original custom designed spin testing facility was constructed. Driven by a 40HP, 40,000rpm air turbine, the spin rig is housed in a vacuum chamber of phi72inx40in (1829mmx1016mm). The heavily armored chamber is furnished with 9 viewports. This facility enables unprecedented investigations of FBO events. In parallel, a 15.4ft (4.7m) long phi4.1inch (105mm

  9. Interface Effects on the Quasi-Static and Impact Toughness of Discontinuously Reinforced Aluminum Laminates

    Science.gov (United States)

    Osman, Todd M.; Hassan, Hala A.; Lewandowski, John J.

    2008-08-01

    Trilayer laminates consisting of two layers of aluminum alloy 7093 surrounding one layer of 7093/SiC/15 p were produced via two roll-bonding techniques as well as by adhesive bonding. The effects of systematic changes in interface characteristics ( i.e., weak bond via roll bonding with a thin ductile interlayer material, stronger bond via roll bonding without a thin ductile interlayer, and strongest bond via adhesive bonding with a semibrittle material) on the subsequent laminate toughness was studied. The fracture resistance of the laminates and the constituent materials was examined via instrumented Charpy notched impact testing in the crack-arrester orientation as well as by fracture-toughness testing of bend bars tested in the crack-divider and the crack-arrester orientations. The notched impact resistance of the trilayer crack-arrester laminates was found to be greater than both monolithic 7093/SiC/15 p and 7093 samples of similar global thickness. The laminated structure promoted crack arrest, deflection, and large-scale deformation of the unreinforced layers, producing R-curve behavior. The tendency for interface delamination was predicted and confirmed based on recent mechanics-based analyses. The trilayer laminate structures tested in the crack-divider orientation exhibited a greater R-curve than either of the 7093/SiC/15 p or 7093 samples tested at similar global thickness. Both types of roll-bonded laminates ( i.e., stronger interface and weak interface containing a thin metal interlayer) exhibited a greater enhancement in Charpy impact toughness and mode I fracture toughness than did the adhesively bonded ( i.e., semibrittle interface) laminates. These relative improvements in toughness were rationalized by estimating the contributions to energy absorption by the delamination and crack bridging in these systems and by the effects of the interface type on these processes. These results are generally relevant to the performance of these materials under

  10. Quantitative testing of robustness on superomniphobic surfaces by drop impact.

    Science.gov (United States)

    Nguyen, Thi Phuong Nhung; Brunet, Philippe; Coffinier, Yannick; Boukherroub, Rabah

    2010-12-07

    The quality of a liquid-repellent surface is quantified by both the apparent contact angle θ(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 maintaining a low-friction condition. We designed surfaces covered with nanowires obtained by the vapor-liquid-solid (VLS) growth technique that are able to repel most of the existing nonpolar liquids including those with very low surface tension as well as many polar liquids with moderate to high surface tension. These superomniphobic surfaces exhibit apparent contact angles ranging from 125 to 160° 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 Young's contact angle θ(0) related to the surface tension of the liquid and that the orientational growth of nanowires is a favorable factor for robustness.

  11. Irradiation programme MANITU. Results of impact tests with the irradiated materials of the first irradiation phase (0.8 dpa); Bestrahlungsprogramm MANITU. Ergebnisse der Kerbschlagbiegeversuche mit den bis 0,8 dpa bestrahlten Werkstoffen der ersten Bestrahlungsphase

    Energy Technology Data Exchange (ETDEWEB)

    Rieth, M.; Dafferner, B.; Ries, H.; Romer, O.

    1995-09-01

    The irradiation project MANITU was planned and carried out in the frame of the European Longterm Fusion Materials Development Programme. The problem of the irradiation induced embrittlement of possible martensitic alloy candidates is still unsolved. But after the evaluation of subsize Charpy tests with the unirradiated reference specimens of MANITU a first tendency was recognizable. The mechanical properties of the newly developed low activation 7-10% Cr-W(Ge)VTa alloys are partly better compared to the modified commercial 10-11% Cr-NiMoVNb steels. In the present report the results of instrumented impact tests within the first phase of the MANITU programme (irradiation dose 0.8 dpa, irradiation temperatures 250, 300, 350, 400, and 450 C) are analysed and assessed. Among all examined alloys (MANET-I, MANET-II, K-heat, OPTIFER-Ia, OPTIFER-II, F82H, 9Cr-2WVTa ORNL 3791) the ORNL steel shows the very best embrittlement behaviour after neutron irradiation. (orig.) [Deutsch] Das Bestrahlungsprojekt MANITU wurde im Rahmen des europaeischen Langzeitprogramms fuer Materialentwicklung fuer die Kernfusion geplant und durchgefuehrt. Das Problem der bestrahlungsinduzierten Versproedung bei den in Frage kommenden martensitischen Werkstoffen ist nach wie vor ungeloest. Eine erste Tendenz zeichnete sich jedoch nach der Auswertung der Kerbschlagbiegeversuche an den unbestrahlten miniaturisierten Referenzproben des MANITU-Programms ab. Die neu entwickelten niedrig aktivierbaren 7-10% Cr-W(Ge)VTa-Legierungen weisen gegenueber den modifizierten kommerziellen 10-11% Cr-NiMoVNb-Staehlen teilweise bessere mechanische Eigenschaften auf. Im vorliegenden Bericht werden die Ergebnisse aus den instrumentierten Kerbschlagbiegeversuchen der ersten Phase des MANITU-Programms (Bestrahlungsdosis 0,8 dpa, Bestrahlungstemperaturen 250, 300, 350, 400 und 450 C) analysiert und bewertet. Von den untersuchten Legierungen (MANET-I, MANET-II, Kastencharge, OPTIFER-Ia, OPTIFER-II, F82H, 9Cr-2WVTa ORNL 3791

  12. Irradiation programme MANITU. Results of impact tests with the irradiated materials (0.2 dpa); Bestrahlungsprogramm MANITU. Ergebnisse der Kerbschlagbiegeversuche mit den bis 0,2 dpa bestrahlten Werkstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Rieth, M.; Dafferner, B.; Kunisch, W.; Ries, H.; Romer, O.

    1997-04-01

    The irradiation project MANITU was planned and carried out in the frame of the European Longterm Fusion Materials Development Programme. The problem of the irradiation induced embrittlement of possible martensitic alloy candidates is still unsolved. But after the evaluation of subsize Charpy tests with specimens of MANITU (0.8 dpa) a first tendency was recognizable. The mechanical properties of the newly developed low activation 7-10% Cr-W(Ge)VTa alloys are better compared to the modified commercial 10-11% Cr-NiMoVNb steels. In the present report the results of instrumented impact tests of the MANITU programme (irradiation dose 0.2 dpa, irradiation temperatures 250, 300, 350, 400, and 450 C) are analysed and assessed. Among all examined alloys (MANET-I, MANET-II, K-heat, OPTIFER-Ia, OPTIFER-II, F82H, 9Cr-2WVTa ORNL 3791) the ORNL steel shows the best embrittlement behaviour after neutron irradation. (orig.) [Deutsch] Das Bestrahlungsprojekt MANITU wurde im Rahmen des europaeischen Langzeitprogramms fuer Materialentwicklung fuer die Kernfusion geplant und durchgefuehrt. Das Problem der bestrahlungsinduzierten Versproedung bei den in Frage kommenden martensitischen Werkstoffen ist nach wie vor ungeloest. Eine erste Tendenz zeichnete sich jedoch nach der Auswertung der Kerbschlagbiegeversuche an den bis 0,8 dpa bestrahlten miniaturisierten Proben des MANITU-Programms ab. Die neu entwickelten niedrig aktivierbaren 7-10% Cr-W(Ge)VTa-Legierungen weisen gegenueber den modifizierten kommerziellen 10-11% Cr-NiMoVNb-Staehlen bessere mechanische Eigenschaften auf. Im vorliegenden Bericht werden die Ergebnisse aus den instrumentierten Kerbschlagbiegeversuchen des MANITU-Programms (Bestrahlungsdosis 0,2 dpa, Bestrahlungstemperaturen 250, 300, 350, 400 und 450 C) analysiert und bewertet. Von den untersuchten Legierungen (MANET-I, MANET-II, Kastencharge, OPTIFER-Ia, OPTIFER-II, F82H, 9Cr-2WVTa ORNL 3791) zeigt der ORNL-Stahl das beste Versproedungsverhalten nach

  13. Wavelet analysis in ecology and epidemiology: impact of statistical tests.

    Science.gov (United States)

    Cazelles, Bernard; Cazelles, Kévin; Chavez, Mario

    2014-02-01

    Wavelet analysis is now frequently used to extract information from ecological and epidemiological time series. Statistical hypothesis tests are conducted on associated wavelet quantities to assess the likelihood that they are due to a random process. Such random processes represent null models and are generally based on synthetic data that share some statistical characteristics with the original time series. This allows the comparison of null statistics with those obtained from original time series. When creating synthetic datasets, different techniques of resampling result in different characteristics shared by the synthetic time series. Therefore, it becomes crucial to consider the impact of the resampling method on the results. We have addressed this point by comparing seven different statistical testing methods applied with different real and simulated data. Our results show that statistical assessment of periodic patterns is strongly affected by the choice of the resampling method, so two different resampling techniques could lead to two different conclusions about the same time series. Moreover, our results clearly show the inadequacy of resampling series generated by white noise and red noise that are nevertheless the methods currently used in the wide majority of wavelets applications. Our results highlight that the characteristics of a time series, namely its Fourier spectrum and autocorrelation, are important to consider when choosing the resampling technique. Results suggest that data-driven resampling methods should be used such as the hidden Markov model algorithm and the 'beta-surrogate' method.

  14. 49 CFR 572.166 - Knees and knee impact test procedure.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.166... TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure....

  15. 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…

  16. Predictive genetic testing for cardiovascular diseases: impact on carrier children.

    Science.gov (United States)

    Meulenkamp, Tineke M; Tibben, Aad; Mollema, Eline D; van Langen, Irene M; Wiegman, Albert; de Wert, Guido M; de Beaufort, Inez D; Wilde, Arthur A M; Smets, Ellen M A

    2008-12-15

    We studied the experiences of children identified by family screening who were found to be a mutation carrier for a genetic cardiovascular disease (Long QT Syndrome (LQTS), Hypertrophic Cardiomyopathy (HCM), Familial Hypercholesterolemia (FH)). We addressed the (a) manner in which they perceive their carrier status, (b) impact on their daily lives, and (c) strategy used to cope with these consequences. Children (aged 8-18) who tested positive for LQTS (n=11), HCM (n=6) or FH (n=16), and their parents participated in semi-structured audiotaped interviews. Interview topics included illness perception, use of medication, lifestyle modifications, worries, and coping. Each interview was coded by two researchers. The qualitative analysis was guided by Leventhal's model of self-regulation. The children were overall quite articulate about the disease they were tested for, including its mode of inheritance. They expressed positive future health perceptions, but feelings of controllability varied. Adherence and side-effects were significant themes with regard to medication-use. Refraining from activities and maintaining a non-fat diet were themes concerning lifestyle modifications. Some children spontaneously reported worries about the possibility of dying and frustration about being different from peers. Children coped with these worries by expressing faith in the effectiveness of medication, trying to be similar to peers or, in contrast, emphasizing their "being different." Children generally appeared effective in the way they coped with their carrier status and its implications. Nevertheless, dealing with the daily implications of their condition remains difficult in some situations, warranting continued availability of psychosocial support.

  17. 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.

  18. 基于加速度测量的仪器化冲击试验方法研究%Study on the method of instrumental impact test based on acceleration measurement

    Institute of Scientific and Technical Information of China (English)

    苏文桂; 吴燕瑞; 陈家权; 赵政飞; 温洁明

    2012-01-01

    为研究摆杆在材料冲击过程的动态响应特性及摆杆的振动对测试结果的影响,本文利用虚拟仪器技术构建了一个仪器化冲击测试系统,将加速度传感器用于仪器化冲击试验.试验结果表明,将加速度传感器用于仪器化冲击试验所得的特征曲线与传统仪器化冲击试验特征曲线一致,用加速度传感器测出的数据计算出的冲击功与试验机表盘读数吻合,因此将加速度传感器用于仪器化冲击试验是可行的.通过测量试验中冲击试验机摆锤的加速度,分析材料的冲击性能与摆锤振动特性的关系.运用欧拉-伯努利梁理论对摆杆进行横向固有频率分析和对试验中加速度信号进行功率谱密度分析,得到摆杆在冲击载荷作用下的动态响应与材料的韧脆性之间的关系.研究结果表明,冲击功中的裂纹扩展功反映材料的韧脆性,冲击功中的裂纹扩展功越大,材料的韧性越好;材料韧性越好,摆杆的振动低频所占的能量就越高.%In order to investigate the dynamic responses of the striker arm in the impact process, an instrumental impact system was built by using virtual instrument technique to apply accelerometers in the impact tests. Testing results showed that the characteristic curves obtained from instrumented impact test by applying accelerometer are consistent with that from the traditional instrumented impact test and the impact energy calculated with the accelerometer signal data agreed well with the panel reading data, showing that applying accelerometers for impact test is feasible. By measuring the acceleration of the pendulum of charpy impact machine, the vibration characteristics of the pendulum were studied. The relationship between the dynamic response of the striker arm and the impact properties of the given material was built by analyzing the natural frequency of transverse vibration of striker arm, which was calculated by Euler Bernoulli beam

  19. Influence of Constituent Materials on the Impact Toughness and Fracture Mechanisms of Hot-Roll-Bonded Aluminum Multilayer Laminates

    Science.gov (United States)

    Cepeda-Jiménez, C. M.; Hidalgo, P.; Pozuelo, M.; Ruano, O. A.; Carreño, F.

    2010-01-01

    Two aluminum multilayer laminates have been processed by hot roll bonding following similar processing paths. The first one is constituted by alternated Al 2024 and Al 1050 layers (ALH19) and the second one by alternated Al 7075 and Al 1050 layers (ADH19). The influence of the constituent materials in the multilayer laminates both during the processing at high temperature and during the subsequent mechanical characterization has been analyzed. The mechanical behavior of the as-received materials at the processing conditions has been characterized by hot torsion. Multilayer laminates have been tested at room temperature under impact Charpy tests, three-point bend tests, and shear tests on the interfaces. The relative toughness increase compared to the constituent materials was much higher for the ADH19 laminate based on the high-strength Al 7075 alloy than for the ALH19 laminate. This is attributed to the different fracture mechanism.

  20. Instrumented Charpy : analysis of the instrumentation and the effect of different metallurgical conditions of an ultra-high strength steel on the dynamic fracture toughness

    OpenAIRE

    2009-01-01

    Resumo: O ensaio Charpy clássico, utilizado desde o início do século XX, permite determinar a energia global de fratura, propriedade mecânica conhecida como tenacidade. Esta energia tem caráter qualitativo e na aplicação no projeto estrutural, reduz-se a comparações entre as curvas de transição dúctil-frágil dos materiais. Com o surgimento da instrumentação do ensaio Charpy clássico é possível determinar a propriedade mecânica, tenacidade à fratura dinâmica, KId, muito utilizada na Mecânica d...

  1. 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.

  2. 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

  3. 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.

  4. A Study of the "toss Factor" in the Impact Testing of Cermets by the Izod Pendulum Test

    Science.gov (United States)

    Probst, H B; Mchenry, Howard T

    1957-01-01

    The test method presented shows that the "toss energy" contributed by the apparatus for brittle materials is negligible. The total toss energy is considered to consist of two components. (a) recovered stored elastic energy and (b) kinetic energy contributed directly by the apparatus. The results were verified by high-speed motion pictures of the test in operation. From these photographs, velocities of tossed specimens were obtained and toss energy computed. In addition, impact energies of some titanium carbide base cermets and high-temperature alloys, as measured by the low-capacity Izod pendulum test, compare well with impact energies measured by the NACA drop test.

  5. STUDY ON THE EXPERIMENTAL TECHNIQUES OF DYNAMIC FRACTURE TOUGHNESS OF MATERIALS BASED ON INSTRUMENTED CHARPY IMPACT TEST%基于示波冲击实验材料动态断裂韧度测试技术的研究

    Institute of Scientific and Technical Information of China (English)

    许振琦; 朱世范; 果春焕; 王延春; 姜风春

    2015-01-01

    采用预裂纹Charpy冲击试样,基于示波冲击试验建立了测试材料动态断裂韧度的试验方法.与以往预裂纹试样动态应力强度因子的计算方法不同,采用Timoshenko梁理论,提出了一种简单方法来计算三点弯曲试样的刚度K(a),由此建立了三点弯曲试样动态应力强度因子的计算方法,通过实验测得启裂时间,从而确定动态断裂韧度.采用有限元方法对试样动态应力强度因子的理论计算方法进行了验证.结果表明,建立的计算方法准确、可靠,避免了复杂的数值计算,便于工程应用.

  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. 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.

  8. The Impact of Gender in Oral Proficiency Testing.

    Science.gov (United States)

    O'Loughlin, Kieran

    2002-01-01

    Discusses the role of gender in speaking tests and suggests that in oral interviews it is possible that both interviewing and rating may be highly gendered processes. Audiotaped female and male test-takers who undertook practice IELTS interviews, one with a female interviewer and once with a male interviewer. Results from discourse and test score…

  9. Subtask 12D2: Baseline impact properties of vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Loomis, B.A.; Smith, D.L. [Argonne National Lab., IL (United States)

    1995-03-01

    The objective of this work is to determine the baseline impact properties of vanadium-base alloys as a function of compositional variables. Up-to-date results on impact properties of unirradiated V, V-Ti, V-Cr-Ti and V-Ti-Si alloys are presented and reviewed in this paper, with an emphasis on the most promising class of alloys, i.e., V-(4-5)Cr-(3-5)Ti containing 400-1000 wppm Si. Database on impact energy and ductile-brittle transition temperature (DBTT) has been established from Charpy impact tests on small laboratory as well as production-scale heats. DBTT is influenced most significantly by Cr contents and, to a lesser extent, by Ti contents of the alloys. When combined contents of Cr and Ti were {le}10 wt.%, V-Cr-Ti alloys exhibit excellent impact properties, i.e., DBTT<-200{degrees}C and upper shelf energies of {approx}120-140 J/cm{sup 2}. Impact properties of the production-scale heat of the U.S. reference alloy V-4Cr- 4Ti were as good as those of the laboratory-scale heats. Optimal impact properties of the reference alloy were obtained after annealing the as-rolled products at 1000{degrees}C-1050{degrees}C for 1-2 h in high-quality vacuum. 17 refs., 6 figs., 2 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cepeda-Jimenez, C. M.; Ruano, O. A.; Carreno, F.

    2012-11-01

    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.

  11. Soft Soil Impact Testing and Simulation of Aerospace Structures

    Science.gov (United States)

    Fasanella, Edwin L.; Jackson, Karen E.; Kellas, Sotiris

    2008-01-01

    In June 2007, a 38-ft/s vertical drop test of a 5-ft-diameter, 5-ft-long composite fuselage section that was retrofitted with a novel composite honeycomb Deployable Energy Absorber (DEA) was conducted onto unpacked sand. This test was one of a series of tests to evaluate the multi-terrain capabilities of the DEA and to generate test data for model validation. During the test, the DEA crushed approximately 6-in. and left craters in the sand of depths ranging from 7.5- to 9-in. A finite element model of the fuselage section with DEA was developed for execution in LS-DYNA, a commercial nonlinear explicit transient dynamic code. Pre-test predictions were generated in which the sand was represented initially as a crushable foam material MAT_CRUSHABLE_FOAM (Mat 63). Following the drop test, a series of hemispherical penetrometer tests were conducted to assist in soil characterization. The penetrometer weighed 20-lb and was instrumented with a tri-axial accelerometer. Drop tests were performed at 16-ft/s and crater depths were measured. The penetrometer drop tests were simulated as a means for developing a more representative soil model based on a soil and foam material definition MAT_SOIL_AND FOAM (Mat 5) in LS-DYNA. The model of the fuselage with DEA was reexecuted using the updated soil model and test-analysis correlations are presented.

  12. 16 CFR Figure 1 to Subpart A of... - Glass Impact Test Structure

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Glass Impact Test Structure 1 Figure 1 to Subpart A of Part 1201 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... 1 to Subpart A of Part 1201—Glass Impact Test Structure EC03OC91.004...

  13. 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.

  14. Is the psychological impact of genetic testing moderated by support and sharing of test results to family and friends?

    Science.gov (United States)

    Lapointe, Julie; Dorval, Michel; Noguès, Catherine; Fabre, Roxane; Julian-Reynier, Claire

    2013-12-01

    Receiving the results of genetic tests for a breast and ovarian cancer susceptibility can be a stressful experience. Here we studied the effects of social support (SS) and the sharing of test results on the psychological impact of BRCA1/2 test result disclosure. We also compared carriers and non-carriers on sharing, SS and psychological impact. Five-hundred and twenty-two unaffected women were followed prospectively for 2 years after receiving their test results. Psychological impact was measured on the impact of event scale. Multivariate multi-level models were used, and all the analyses were stratified depending on mutation status (carriers vs non-carriers). Two weeks after receiving their BRCA1/2 results, carriers had shared their test results less frequently than non-carriers (p test results was not significantly associated with psychological impact. Availability of SS was significantly associated with better psychological adjustment across time among carriers (p < 0.01), but not among non-carriers. For female BRCA1/2 mutation carriers, the importance of SS should be stressed, and possible ways of enlisting people in their entourage for this purpose should be discussed in the context of clinical encounters.

  15. 49 CFR 572.126 - Knees and knee impact test procedure.

    Science.gov (United States)

    2010-10-01

    ...-year-old Child Test Dummy, Beta Version § 572.126 Knees and knee impact test procedure. (a) Knee... procedure in section 572.127(c), the peak resistance force as measured with the test probe mounted... exterior surface. (3) Align the test probe so that throughout its stroke and at contact with the knee it...

  16. 49 CFR 572.136 - Knees and knee impact test procedure.

    Science.gov (United States)

    2010-10-01

    ... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.136 Knees and knee impact test procedure... as measured with the test probe-mounted accelerometer must be not less than 3450 N (776 lbf) and not... tibia may contact any exterior surface. (3) Align the test probe so that throughout its stroke and...

  17. The Potential Impact of Not Being Able to Create Parallel Tests on Expected Classification Accuracy

    Science.gov (United States)

    Wyse, Adam E.

    2011-01-01

    In many practical testing situations, alternate test forms from the same testing program are not strictly parallel to each other and instead the test forms exhibit small psychometric differences. This article investigates the potential practical impact that these small psychometric differences can have on expected classification accuracy. Ten…

  18. Dynamic behavior of porous concretes under drop weight impact testing

    NARCIS (Netherlands)

    Agar Ozbek, A.S.; Weerheijm, J.; Schlangen, E.; Breugel, K. van

    2013-01-01

    Porous concrete is used as a construction material in various applications mainly as a permeable cementitious material. However, its response under impact loading is generally not considered. Due to the high percentage of its intentional meso-size air pores, porous concrete has a moderate static str

  19. Rationale for and dimensions of impact surfaces for biofidelity tests of different sizes of frontal and side impact dummies.

    Science.gov (United States)

    Irwin, Annette L; Mertz, Harold J

    2010-11-01

    The biofidelity impact response corridors that were used to develop the Hybrid III family of dummies were established by scaling the various biofidelity corridors that were defined for the Hybrid III mid-size, adult male dummy. Scaling ratios for the responses of force, moment, acceleration, velocity, deflection, angle, stiffness and time were developed using dimensions and masses that were prescribed for the dummies. In addition, an elastic modulus ratio for bone was used to account for the differences between child and adult bone elastic properties. A similar method is being used by ISO/TC22/SC12/WG 5 to develop biofidelity guidelines for a family of side impact dummies based on scaling the biofidelity impact response corridors that are prescribed for WorldSID, a mid-size, adult male dummy. While the various biomechanical impact response requirements for the Hybrid III family of dummies and the WorldSID are documented in the literature, the scaling used to prescribe the dimensions of the impact surfaces that are used for the various biofidelity tests for various sizes of dummies are not documented. This paper describes the rationale for how these impact surfaces should be scaled, gives the scaling equations, and gives the dimensions of the impact surfaces that should be used for the various biofidelity tests of the different sizes of adult and child dummies. For future PMHS and human volunteer tests that are conducted to define impact biofidelity guidelines, it is recommended that the impact surfaces be scaled for the test subject size so that the data can be appropriately normalized to any size subject.

  20. 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.

  1. 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.

  2. Development of computer simulation models for pedestrian subsystem impact tests

    NARCIS (Netherlands)

    Kant, R.; Konosu, A.; Ishikawa, H.

    2000-01-01

    The European Enhanced Vehicle-safety Committee (EEVC/WG10 and WG17) proposed three component subsystem tests for cars to assess pedestrian protection. The objective of this study is to develop computer simulation models of the EEVC pedestrian subsystem tests. These models are available to develop a

  3. Impact of Inclusion or Exclusion of Repeaters on Test Equating

    Science.gov (United States)

    Puhan, Gautam

    2011-01-01

    This study examined the effect of including or excluding repeaters on the equating process and results. New forms of two tests were equated to their respective old forms using either all examinees or only the first timer examinees in the new form sample. Results showed that for both tests used in this study, including or excluding repeaters in the…

  4. Determination of Acoustic Effects on Marine Mammals and Sea Turtles for the Atlantic Fleet Training and Testing Environmental Impact Statement/Overseas Environmental Impact Statement

    Science.gov (United States)

    2013-08-23

    Mammals and Sea Turtles for the Atlantic Fleet Training and Testing Environmental Impact Statement/Overseas Environmental Impact Statement...Mammals and Sea Turtles for the Atlantic Fleet Training and Testing Environmental Impact Statement/Overseas Environmental Impact Statement 5a...methodology to estimate acoustic effects on designated marine fauna, which include marine mammals and sea turtles . This report describes the process

  5. Impact echo data from bridge deck testing: Visualization and interpretation

    OpenAIRE

    Gucunski, N.; Slabaugh, G.G.; Wang, Z; Fang, T.; A. Maher

    2008-01-01

    Accurate assessment of the condition of bridges leads to their economic management. Ultrasonic seismic methods can be successfully used for this purpose through evaluation of changes in material characteristics and detection of the development of defects and zones of deterioration. The impact echo (IE) method is of special benefit in evaluation of corrosion-induced deck delamination, due to the method's nondestructive nature, speed of evaluation, and ability to detect delaminated zones at var...

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

    Science.gov (United States)

    Maldonado, Emanuel; Sunagar, Kartik; Almeida, Daniela; Vasconcelos, Vitor; Antunes, Agostinho

    2014-01-01

    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.

  7. 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.

  8. Effect of Grain Boundary Character Distribution on the Impact Toughness of 410NiMo Weld Metal

    DEFF Research Database (Denmark)

    Divya, M.; Das, Chitta Ranjan; Chowdhury, Sandip Ghosh;

    2016-01-01

    Grain boundary character distributions in 410NiMo weld metal were studied in the as-welded, first-stage, and second-stage postweld heat treatment (PWHT) conditions, and these were correlated with the Charpy-V impact toughness values of the material. The high impact toughness values in the weld me...

  9. Impact energy analysis of quenched and tempered fine grain structural steel specimens after weld thermal cycle simulation

    Directory of Open Access Journals (Sweden)

    M. Dunđer

    2014-10-01

    Full Text Available The paper presents impact energy results of thermal cycle simulated specimens of quenched and tempered fine grain structural steel S960QL. These results are obtained by examining notched Charpy specimens. Upon performed metallographic analysis and measured hardness, total impact energy is separated into ductile and brittle components.

  10. Polynomial cointegration tests of anthropogenic impact on global warming

    OpenAIRE

    M. Beenstock; Reingewertz, Y.; 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...

  11. Impact toughness and fracture toughness of austempered ductile iron

    OpenAIRE

    Liu, Jingcheng; Guoxiong SUN

    2004-01-01

    The impact toughness and fracture toughness ofaustermpered ductile iron (ADI) are described. The notched and un-notched charpy impact toughness of ADI at room temperature are somewhat lower than that of steel castings or forged steel pieces, however, they are approximately three times higher than that of mormal pearlitic ductile iron. The impact toughness of ADI decreases with decreasing temperature; but at -40 ℃ it still maintains about 70% of the value at room temperature. The properties of...

  12. An Experimental Technique for Developing Intermediate Strain Rates in Ductile Metals

    Science.gov (United States)

    2008-03-01

    Instrumented Charpy tests rely on a strain gage instrumented load cell to col- lect a load-history during impact. However, the same fundamental limitations due...to wave-propagation and inertia effects are inherent in the instrumented Charpy test , as other instrumented impact tests , limiting the velocities at...lower velocities, the instrumentation of the Charpy test has transformed it from an al- most purely subjective impact survivability test to

  13. Influence of helium on impact properties of reduced-activation ferritic/martensitic Cr-steels

    Science.gov (United States)

    Lindau, R.; Möslang, A.; Preininger, D.; Rieth, M.; Röhrig, H. D.

    Instrumented Charpy impact tests of the reduced activation type 8Cr2WVTa steel F82H have been performed after homogeneous implantation of 300 appm helium at 250°C. The results are compared with investigations on mixed spectrum neutron irradiated (HFR Petten) specimens. After neutron irradiation at 250°C to the same low damage dose of 0.2 dpa, the ductile-brittle transition temperature shift (ΔDBTT) amounts to 18°C, whereas a much higher ΔDBTT of 42°C has been measured after helium implantation. These results are compared with other neutron irradiated ferritic/martensitic steels having different boron levels and thus different helium contents. A model is proposed which describes the dynamic brittle fracture of martensitic/ferritic steels by a stress-induced propagation of micro-cracks, taking into account radiation induced hardening as well as helium bubble formation.

  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. Normalization of Impact Energy by Laminate Thickness for Compression After Impact Testing

    Science.gov (United States)

    Nettles, A. T.; Hromisin, S. M.

    2013-01-01

    The amount of impact energy used to damage a composite laminate is a critical parameter when assessing residual strength properties. The compression after impact (CAI) strength of impacted laminates is dependent upon how thick the laminate is and this has traditionally been accounted for by normalizing (dividing) the impact energy by the laminate's thickness. However, when comparing CAI strength values for a given lay-up sequence and fiber/resin system, dividing the impact energy by the specimen thickness has been noted by the author to give higher CAI strength values for thicker laminates. A study was thus undertaken to assess the comparability of CAI strength data by normalizing the impact energy by the specimen thickness raised to a power to account for the higher strength of thicker laminates. One set of data from the literature and two generated in this study were analyzed by dividing the impact energy by the specimen thickness to the 1, 1.5, 2, and 2.5 powers. Results show that as laminate thickness and damage severity decreased, the value which the laminate thickness needs to be raised to in order to yield more comparable CAI data increases.

  16. 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.

  17. 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.

  18. Heavy-Ion Radiation Impact on a 4Mb FRAM under Different Test Conditions

    CERN Document Server

    Gupta, V.; Tsiligiannis, G.; Zadeh, A.; Javanainen, A.; Virtanen, A.; Puchner, H.; Saigne, F.; Wrobel, F.; Dilillo, L.

    2015-01-01

    The impact of heavy-ions on commercial Ferroelectric Memories (FRAMs) is analyzed. The influence of different test modes (static and dynamic) on this memory is investigated. Static test results show that the memory is prone to temporary effects occurring in the peripheral circuitry. Dynamic tests results show a high sensitivity of this memory to heavy-ions.

  19. 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.

  20. 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.

  1. 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...

  2. Processing and impact properties of steel based laminated composites; Procesado y propiedades de impacto de materiales compuestos laminados de base hierro

    Energy Technology Data Exchange (ETDEWEB)

    Carreno, F.; Pozuelo, M.; Chao, J.; Ruano, O. A.

    2001-07-01

    A seven layers steel based laminated composite (four ultra-high carbon steel, UHCS, layers and three mild steel, MS layers) has been processed by rolling bonding and its microstructure and impact properties have been studied. Suitable parameters of temperature and thickness reduction were selected to obtain a finer microstructure relative to the original materials components. This finer microstructure induces improved mechanical properties. Charpy impact tests values in both crack arrester and crack divider orientations improve the values of the UHCS constituent materials. Furthermore, the crack arrester orientation value exceed that of the MS material. The delamination, which is controlled by interface bonding, plays a key role defecting the crack, absorbing energy and imposing the nucleation of new cracks in the next materials layers. (Author) 10 refs.

  3. 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.

  4. Determination of Constitutive Model Constants from Cylinder Impact Tests

    Science.gov (United States)

    1987-12-01

    HONEYWELL, INC./ARMAMENT SYSTEMS DIVISION) FOR NAVAL SURFACE WARFARE CENTER RESEARCH AND TECHNOLOGY DEPARTMENT DECEMBER 1988 Approved for public release...primary application is for higher strain rates, and the strain rate constant was therefore selected to give better correlation with the higher strain...to that of the test data. The new constants (C and C2) were obtained in conjunction with the previous values of C. and C4, as talen from Reference 2

  5. Small Scale Drop Tower Test for Practice Torpedo Impact Modelling

    Science.gov (United States)

    2012-06-01

    Table E3. Tensile test results for the aluminium 6061 -T6 model hull plates. 2 coupons were cut with their length parallel to the long side of the...and without stiffeners and aluminium plate without stiffeners. A qualitative comparison of the results for the three model hull forms shows that...stiffeners tend to limit the extent of the dent, that aluminium plate has a greater elastic response than that of both stiffened and unstiffened steel

  6. Point of care testing: The impact of nanotechnology.

    Science.gov (United States)

    Syedmoradi, Leila; Daneshpour, Maryam; Alvandipour, Mehrdad; Gomez, Frank A; Hajghassem, Hassan; Omidfar, Kobra

    2017-01-15

    Point-of-care (POC) diagnostic devices are integral in the health care system and particularly for the diagnosis and monitoring of diseases. POC testing has a variety of advantages including the ability to provide rapid and accurate results, ease of use, low cost, and little need for specialized equipment. One of the goals of POC testing is the development of a chip-based, miniaturized, portable, and self-containing system that allows for the assay of different analytes in complex samples. To achieve these goals, many researchers have focused on paper-based and printed electrode technologies as the material for fabricating POC diagnostic systems. These technologies are affordable, sensitive, user-friendly, rapid, and scalable for manufacturing. Moreover, the combination such devices with nanomaterials provide a path for the development of highly sensitive and selective biosensors for future generation POC tools. This review article discusses present technologies in on-site or at home POC diagnostic assays implemented in paper-based microfluidic and screen printing devices over the past decade as well as in the near future. In addition, recent advances in the application of nanomaterials such as gold nanoparticles, carbon nanotubes (CNTs), magnetic nanoparticles, and graphene in POC devices will be reviewed. The factors that limit POC testing to become real world products and future directions are also identified.

  7. Sensitivity of Occupant Response Subject to Prescribed Corridors for Impact Testing

    Directory of Open Access Journals (Sweden)

    J.R. Crandall

    1996-01-01

    Full Text Available A technology to study the sensitivity of impact responses to prescribed test conditions is presented. Motor vehicle impacts are used to illustrate the principles of this sensitivity technology. Impact conditions are regulated by specifying either a corridor for the acceleration time history or other test parameters such as velocity change, static crush distance, and pulse duration. By combining a time domain constrained optimization method and a multirigid body dynamics simulator, the upper and lower bounds of occupant responses subject to the regulated corridors were obtained. It was found that these prescribed corridors may be either so wide as to allow extreme variations in occupant response or so narrow that they are physically unrealizable in the laboratory test environment. A new corridor based on specifications for the test parameters of acceleration, velocity. crush distance, and duration for frontal vehicle impacts is given.

  8. 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.

  9. Development of compatibility assessments for full-width and offset frontal impact test procedures in FIMCAR

    NARCIS (Netherlands)

    Adolph, T.; Schwedhelm, H.; Lazaro, I.; Versmissen, A.C.M.; Edwards, M.; Thomson, R.; Johannsen, H.

    2014-01-01

    The goal of the project FIMCAR (Frontal Impact and Compatibility Assessment Research) was to define an integrated set of test procedures and associated metrics to assess a vehicle's frontal impact protection, which includes self-And partner-protection. For the development of the set, two different f

  10. On the impact testing of cyclotrimethylene trinitramine crystals with different internal qualities

    NARCIS (Netherlands)

    Bouma, R.H.B.; Boluijt, A.G.; Verbeek, H.J.; Heijden, A.E.D.M. van der

    2008-01-01

    Impact testing of various cyclotrimethylene trinitramine (RDX) samples has been carried out with the Ballistic Impact Chamber (BIC). Numerical simulations have been performed to guide its experimental design and explain the phenomena that are observed in the measured pressure evolution. The experime

  11. The Impact of Test Dimensionality, Common-Item Set Format, and Scale Linking Methods on Mixed-Format Test Equating

    Science.gov (United States)

    Öztürk-Gübes, Nese; Kelecioglu, Hülya

    2016-01-01

    The purpose of this study was to examine the impact of dimensionality, common-item set format, and different scale linking methods on preserving equity property with mixed-format test equating. Item response theory (IRT) true-score equating (TSE) and IRT observed-score equating (OSE) methods were used under common-item nonequivalent groups design.…

  12. Psychological impact of genetic testing for cancer susceptibility: an update of the literature.

    Science.gov (United States)

    Meiser, Bettina

    2005-12-01

    This article presents an overview of the rapidly evolving body of literature on the psychological impact of genetic testing for hereditary breast/ovarian cancer susceptibility, hereditary non-polyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP). Uptake of genetic testing for BRCA1/2 and HNPCC-related mutations is more consistently related to psychological factors, rather than sociodemographic variables. Most studies on the psychological impact of genetic testing amongst individuals who have never been affected by cancer demonstrate that non-carriers derive significant psychological benefits from genetic testing, while no adverse effects have been observed amongst carriers. These benefits are more clear-cut for HNPCC, compared to hereditary breast/ovarian cancer, reflecting differences in risk management options. The few studies available on individuals affected with cancer indicate that the impact of genetic testing is mediated and amplified by their former experience of cancer. Future directions and challenges of research in this area are reviewed. In particular, more empirical data are needed on the broader impact of genetic testing on those with inconclusive results or results of uncertain significance. As genetic testing is becoming available for other types of familial cancer, additional investigations will be needed as there is evidence to suggest that the impact of genetic testing may be unique to each type of familial cancer.

  13. Measurement of the dynamic fracture toughness with notched PMMA specimen under impact loading

    OpenAIRE

    2009-01-01

    International audience; In the present study three-point-bend impact experiments were conducted using an instrumented Charpy pendulum with a laser displacement measurement to better understand the correlation between impact velocity and the dynamic effects observed on the load-time curves. The experiments were performed at impact velocities ranging from 1 to 4 m/s. The aim of this work is to measure the dynamic fracture toughness at high impact velocities where the classical method is limited...

  14. The psychological impact of predictive genetic testing for Huntington's disease: a systematic review of the literature.

    Science.gov (United States)

    Crozier, S; Robertson, N; Dale, M

    2015-02-01

    Huntington's disease (HD) is a neurodegenerative genetic condition for which a predictive genetic test by mutation analysis has been available since 1993. However, whilst revealing the future presence of the disease, testing may have an adverse psychological impact given that the disease is progressive, incurable and ultimately fatal. This review seeks to systematically explore the psychological impact of genetic testing for individuals undergoing pre-symptomatic mutation analysis. Three databases (Medline, PsycInfo and Scopus) were interrogated for studies utilising standardised measures to assess psychological impact following predictive genetic testing for HD. From 100 papers initially identified, eight articles were eligible for inclusion. Psychological impact of predictive genetic testing was not found to be associated with test result. No detrimental effect of predictive genetic testing on non-carriers was found, although the process was not found to be psychologically neutral. Fluctuation in levels of distress was found over time for carriers and non-carriers alike. Methodological weaknesses of published literature were identified, notably the needs of individuals not requesting genetic testing, as well as inadequate support for individuals registering elevated distress and declining post-test follow-up. Further assessment of these vulnerable individuals is warranted to establish the extent and type of future psychological support.

  15. Determination of Acoustic Effects on Marine Mammals and Sea Turtles for the Hawaii-Southern California Training and Testing Environmental Impact Statement/Overseas Environmental Impact Statement

    Science.gov (United States)

    2013-08-23

    Mammals and Sea Turtles for the Hawaii-Southern California Training and Testing Environmental Impact Statement/Overseas Environmental Impact...Effects on Marine Mammals and Sea Turtles for the Hawaii- Southern California Training and Testing Environmental Impact Statement/Overseas...program uses quantitative analysis methodology to estimate acoustic effects on designated marine fauna, which include marine mammals and sea turtles . This

  16. Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

    Science.gov (United States)

    Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

    2014-01-01

    Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  17. Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

    Directory of Open Access Journals (Sweden)

    Elias Randjbaran

    2014-01-01

    Full Text Available Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  18. DYNAMIC ANALYSIS OF A DOUBLE IMPACT TRIAXIAL TEST ON SAND BY THE FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    Mohammed Y. Fattah,

    2011-04-01

    Full Text Available Impact problems have recently been the subject of intense research. Impact tests have found a great interest by several researchers, and dynamic testing apparatus were developed in different laboratories. Inaddition, several theoretical models were developed to simulate impact tests theoretically and get the corresponding stress-strain relations. A general mixed finite element formulation (u – w – π is presented in this paper. This formulation includes the inertia effects and the materials (solid grains and water are considered compressible. The application of this formulation in solving impact problems of dry sand is made by restricting the boundary conditions concerning the pore fluid, and comparisons are made between laboratory tests conducted at the University of Baghdad in 1989 against elasto-plastic model named ALTERNAT are made herein. A comparison is made between the experimental results and theoretical ones which are obtained by simulating the impact tests using the finite element method. The ALTERNAT model gave very good predictions for displacements of dense (Dr = 75 % sands when subjected to double impacts.

  19. Psychological impact of genetic testing for Huntington's disease: an update of the literature.

    Science.gov (United States)

    Meiser, B; Dunn, S

    2000-11-01

    Genetic testing has been available for Huntington's disease for longer than any other adult onset genetic disorder. The discovery of the genetic mutation causing Huntington's disease made possible the use of predictive testing to identify currently unaffected carriers. Concerns have been raised that predictive testing may lead to an increase in deaths by suicide among identified carriers, and these concerns set in motion research to assess the psychological impact of predictive testing for Huntington's disease. This review article provides an overview of the literature and draws implications for clinical practice. About 10%-20% of people at risk request testing when approached by registries or testing centres. Most of the evidence suggests that non-carriers and carriers differ significantly in terms of short term, but not long term, general psychological distress. Adjustment to results was found to depend more on psychological adjustment before testing than the testing result itself. Although risk factors for psychological sequelae have been identified, few adverse events have been described and no obvious contraindications for testing people at risk have been identified. The psychological impact of testing may depend on whether testing was based on linkage analysis or mutation detection. Cohorts enrolled in mutation detection programmes have higher levels of depression before and after testing, compared with people who sought genetic testing when linkage analysis was available. There is evidence that people who choose to be tested are psychologically selected for a favourable response to testing. The impact of testing on people in settings where less intensive counselling protocols and eligibility criteria are used is unknown, and genetic testing is therefore best offered as part of comprehensive specialist counselling.

  20. 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…

  1. An Exploration of the Impact of Accountability Testing on Teaching in Urban Elementary Classrooms

    Science.gov (United States)

    Bisland, Beverly Milner

    2015-01-01

    This study explores accountability testing in the elementary schools of New York City with particular emphasis on the impact of a statewide social studies test on the value given to social studies instruction in comparison to other subjects. The attitudes of a group of elementary teachers are examined. Some of the teachers taught all subjects in…

  2. 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…

  3. 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

    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...

  4. 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.

  5. Impact of Acoustic Standing Waves on Structural Responses: Reverberant Acoustic Testing (RAT) vs. Direct Field Acoustic Testing (DFAT)

    Science.gov (United States)

    Kolaini, Ali R.; Doty, Benjamin; Chang, Zensheu

    2012-01-01

    Loudspeakers have been used for acoustic qualification of spacecraft, reflectors, solar panels, and other acoustically responsive structures for more than a decade. Limited measurements from some of the recent speaker tests used to qualify flight hardware have indicated significant spatial variation of the acoustic field within the test volume. Also structural responses have been reported to differ when similar tests were performed using reverberant chambers. To address the impact of non-uniform acoustic field on structural responses, a series of acoustic tests were performed using a flat panel and a 3-ft cylinder exposed to the field controlled by speakers and repeated in a reverberant chamber. The speaker testing was performed using multi-input-single-output (MISO) and multi-input-multi-output (MIMO) control schemes with and without the test articles. In this paper the spatial variation of the acoustic field due to acoustic standing waves and their impacts on the structural responses in RAT and DFAT (both using MISO and MIMO controls for DFAT) are discussed in some detail.

  6. Design and Construction of a One-Stage Gas Gun for High Velocity Impact Tests

    Directory of Open Access Journals (Sweden)

    Gamboa-Castellanos Ricardo Alberto

    2015-03-01

    Full Text Available High impact tests are characterized by a projectile traveling at high speed as well as complex events such as flying fragments due to the velocity at which the impact occurs; however, these tests have become increasingly popular due to the need for more stringent protective material requirements nowadays. In this paper, the design and construction of a one-stage light gas gun for ballistic testing is presented. This particular design is characterized by its simplicity, excellent performance at low cost and compact dimensions, when compared to commercial systems, presenting an affordable option for materials characterization for high velocity impact tests. The results are completed with the characterization of an armor grade material, obtaining the ballistic limit of the material, as well as demonstrating the effectiveness and versatility of the equipment.

  7. 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

  8. Test study on the performance of shielding configuration with stuffed layer under hypervelocity impact

    Science.gov (United States)

    Ke, Fa-wei; Huang, Jie; Wen, Xue-zhong; Ma, Zhao-xia; Liu, Sen

    2016-10-01

    In order to study the cracking and intercepting mechanism of stuffed layer configuration on the debris cloud and to develop stuffed layer configuration with better performance, the hypervelocity impact tests on shielding configurations with stuffed layer were carried out. Firstly, the hypervelocity impact tests on the shielding configuration with stuffed layer of 3 layer ceramic fibre and 3 layer aramid fibre were finished, the study results showed that the debris cloud generated by the aluminum sphere impacting bumper at the velocity of about 6.2 km/s would be racked and intercepted by the stuffed layer configuration efficiently when the ceramic fibre layers and aramid fibre layers were jointed together, however, the shielding performance would be declined when the ceramic fibre layers and aramid fibre layers were divided by some distance. The mechanism of stuffed layer racking and intercepting the debris cloud was analyzed according to the above test results. Secondly, based on the mechanism of the stuffed layer cracking and intercepint debirs cloud the hypervelocity impact tests on the following three stuffed layer structures with the equivalent areal density to the 1 mm-thick aluminum plate were also carried out to compare their performance of cracking and intercepting debris cloud. The mechanisms of stuffed layer racking and intercepting the debris cloud were validated by the test result. Thirdly, the influence of the stuffed layer position on the shielding performance was studied by the test, too. The test results would provide reference for the design of better performance shielding configuration with stuffed layer.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Junliang Chang

    2014-11-01

    Full Text Available 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. Through building model, simulation analysis, and construction of an impact test-bed of high-flow water medium relief valve, the dynamic performance of high-flow water medium relief valve is detected. The setting pressure of relief valve, the accumulator volume and the filling fluid pressure, and the damping of cartridge valve can be changed, and the dynamic performance of high-flow water medium relief valve under different impact loads is detected. The results show that the designed impact test-bed of high-flow water medium relief valve could provide required high-pressure and high-flow emulsion for the tested water medium relief valve, and it could control the strength of impact load, which is an energy saving, high efficiency, and low cost method.

  11. A systematic review of perceived risks, psychological and behavioral impacts of genetic testing.

    Science.gov (United States)

    Heshka, Jodi T; Palleschi, Crystal; Howley, Heather; Wilson, Brenda; Wells, Philip S

    2008-01-01

    Genetic testing may enable early disease detection, targeted surveillance, and result in effective prevention strategies. Knowledge of genetic risk may also enable behavioral change. However, the impact of carrier status from the psychological, behavior, and perceived risk perspectives is not well understood. We conducted a systematic review to summarize the available literature on these elements. An extensive literature review was performed to identify studies that measured the perceived risk, psychological, and/or behavioral impacts of genetic testing on individuals. The search was not limited to specific diseases but excluded the impacts of testing for single gene disorders. A total of 35 articles and 30 studies were included. The studies evaluated hereditary nonpolyposis colorectal carcinoma, hereditary breast and ovarian cancer, and Alzheimer disease. For affective outcomes, the majority of the studies reported negative effects on carriers but these were short-lived. For behavioral outcomes, an increase in screening behavior of varying rates was demonstrated in carriers but the change in behaviors was less than expected. With respect to perceived risk, there were generally no differences between carriers and noncarriers by 12 months after genetic testing and over time risk perception decreased. Overall, predispositional genetic testing has no significant impact on psychological outcomes, little effect on behavior, and did not change perceived risk. It seems as though better patient education strategies are required. Our data would suggest better knowledge among carriers would not have significant psychological impacts and therefore, it is worth pursuing improved educational strategies.

  12. Non-destructive testing of barely visible impact damage in polymer matrix composites

    Institute of Scientific and Technical Information of China (English)

    ZHANG Z Y; M. O. W. Richardson

    2004-01-01

    Barely visible impact damage (BVID) is developed when polymer matrix composites are subjected to impact loading. The damage has an adverse effect on structural integrity, and potentially leads to catastrophic failure.Thus it is important to employ a variety of advanced non-destructive testing (NDT) techniques in parallel to unambiguously determine the integrity of composite systems. This study deals with damage evaluation using visual inspection, ultrasonic C-scan, electronic speckle pattern interferometry (ESPI), electronic shearography (ES) and optical deformation and strain measurement system (ODSMS). Internal damage was introduced using an instrumented falling weight impact test (IFWIT) machine by controlling the combination of striker mass and releasing height. It was found that different NDT techniques were successfully employed to identify and visualise the impact induced internal damage. Experimental results generated from these techniques show a good agreement in damage identification and determination. The features, capabilities and limitations associated with these techniques were briefly discussed.

  13. Violent wave impacts on vertical and inclined walls: Large scale model tests

    DEFF Research Database (Denmark)

    Obhrai, C.; Bullock, G.; Wolters, G.

    2005-01-01

    New data is presented from large scale model tests where combined measurements of wave pressure and aeration have been made on the front of a vertical and an inclined wall. The shape of the breaking wave was found to have a significant effect on the distribution of the wave impact pressures...... on the wall. The characteristics of violent wave impacts are discussed and related to the impulse on the structure....

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mok, G.C.; Carlson, R.W.; Lu, S.C.; Fischer, L.E.

    1995-09-01

    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.

  16. Railgun Application for High Energy Impact Testing of Nano-Reinforced Kevlar-Based Composite Materials

    Science.gov (United States)

    Micheli, D.; Vricella, A.; Pastore, R.; Morles, R. B.; Marchetti, M.

    2013-08-01

    An advanced electromagnetic accelerator, called railgun, has been assembled and tuned in order to perform high energy impact test on layered structures. Different types of layered composite materials have been manufactured and characterized in terms of energy absorbing capability upon impact of metallic bullets fired at high velocity. The composite materials under testing are manufactured by integrating several layers of Kevlar fabric and carbon fiber ply within a polymeric matrix reinforced by carbon nanotubes at 1% of weight percentage. The experimental results show that the railgun-device is a good candidate to perform impact testing of materials in the space debris energy range, and that carbon nanotubes may enhance, when suitably coupled to the composite's matrix, the excellent antiballistic properties of the Kevlar fabrics.

  17. 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.

  18. Improving Impact Strength Recovery of Fractured and Healed Rice Husks Fibre Reinforced Polypropylene Composites.

    Directory of Open Access Journals (Sweden)

    Odhong, O.V.E

    2016-10-01

    Full Text Available Rice husks fibre reinforced polypropylene composite (rhfrpc is a natural plant fibre reinforced polymer composite having advantages of high strength, light weight and affordability. They are commonly used for light load structural and non structural applications. They are mainly used as particle boards, for fencing post, roofing tiles, for interiors of car and aircrafts among other usages. This material once cracked by impact forces cannot be repaired using traditional repair methods for engineering materials such as metals or other composites that can be repaired by welding or by patch repair methods respectively, thus a method of repair of rice husks fibre reinforced polypropylene composites by refilling the damaged volume by injection of various healing agents has been investigated. The composite coupons were produced by injection moulding, cooled sufficiently and prepared for charpy impact tests. Test results for pristine coupons were a maximum of 48 J/mm2 . The destroyed coupons were then subjected to healing in a fabricated healing fixture. Healing agents such as epoxy resin, ethyl cyanoacrylate, and tannin gum have been investigated for their use as possible healing agents to fill the damaged volume and perform healing action at the fractured surfaces. The impact test results were recorded and compared with those of unhealed pristine coupons. The recovered strengths were a maximum of 60 J/mm2 translating into a 125% impact strength recovery, and this is good enough for the healed composites to be recommended for reuse in their second lives of their respective original functions.

  19. Safety assessment characteristics of pedestrian legform impactors in vehicle-front impact tests.

    Science.gov (United States)

    Matsui, Yasuhiro

    2014-12-01

    This study investigated the characteristics of safety assessment results of front-area vehicle impact tests carried out using the Transport Research Laboratory (TRL) legform impactor and a flexible legform impactor (FLEX legform impactor). Different types of vehicles (sedan, sport utility vehicle, high-roof K-car, and light cargo van) were examined. The impact locations in the study were the center of the bumper and an extremely stiff structure of the bumper (i.e., in front of the side member) of each tested vehicle. The measured injury criteria were normalized by injury assessment reference values of each legform impactor. The test results for center and side-member impacts indicated that there were no significant differences in ligament injury assessments derived from the normalized knee ligament injury measures between the TRL legform impactor and the FLEX legform impactor. Evaluations made using the TRL legform impactor and the FLEX legform impactor are thus similar in the vehicle safety investigation for knee ligament injury. Vehicle-center impact test results revealed that the tibia fracture assessments derived from the normalized tibia fracture measures did not significantly differ between the TRL legform impactor and the FLEX legform impactor. However, for an impact against an extremely stiff structure, there was a difference in the tibia fracture assessment between the FLEX legform impactor and the TRL legform impactor owing to their different sensor types.

  20. 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.

  1. The cryogenic bonding evaluation at the metallic-composite interface of a composite overwrapped pressure vessel with additional impact investigation

    Science.gov (United States)

    Clark, Eric A.

    A bonding evaluation that investigated the cryogenic tensile strength of several different adhesives/resins was performed. The test materials consisted of 606 aluminum test pieces adhered to a wet-wound graphite laminate in order to simulate the bond created at the liner-composite interface of an aluminum-lined composite overwrapped pressure vessel. It was found that for cryogenic applications, a flexible, low modulus resin system must be used. Additionally, the samples prepared with a thin layer of cured resin -- or prebond -- performed significantly better than those without. It was found that it is critical that the prebond surface must have sufficient surface roughness prior to the bonding application. Also, the aluminum test pieces that were prepared using a surface etchant slightly outperformed those that were prepared with a grit blast surface finish and performed significantly better than those that had been scored using sand paper to achieve the desired surface finish. An additional impact investigation studied the post impact tensile strength of composite rings in a cryogenic environment. The composite rings were filament wound with several combinations of graphite and aramid fibers and were prepared with different resin systems. The rings were subjected to varying levels of Charpy impact damage and then pulled to failure in tension. It was found that the addition of elastic aramid fibers with the carbon fibers mitigates the overall impact damage and drastically improves the post-impact strength of the structure in a cryogenic environment.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

    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)

  3. What's the Point? How Point-of-Care STI Tests Can Impact Infected Patients.

    Science.gov (United States)

    Huppert, Jill; Hesse, Elizabeth; Gaydos, Charlotte A

    2010-03-01

    Point-of-care (POC) tests are an important strategy to address the epidemic of sexually transmitted infections (STIs) among both adolescents and young adults. While access to care and confidentiality are major barriers to STI care, POC tests allow the clinician to provide immediate and confidential test results and treatment. In addition, POC test results constitute a "teachable moment"; that is, an opportunity to provide immediate feedback to the patient that may impact his/her risk behaviors. This paper reviews published data and manufacturer's product literature describing current point-of-care STI tests, including studies of test performance as well as impact on treatment intervals and disease spread. It presents theoretical and proposed pitfalls and solutions of implementing POC tests in clinical settings, non-traditional settings, and home care venues. We reviewed the available STI tests according to the World Health Organization (WHO) criteria for judging POC tests: the "ASSURRED" criteria (Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, Delivered).

  4. Impact of 50% Alcohol to Jet Blends on Aviation Turbine Fuel Coalescence - Navy Coalescence Test

    Science.gov (United States)

    2014-10-17

    Aviation Turbine Fuels5 are not feasible. The total water concentration of three samples from the influent and effluent of the filter-separator...International. ASTM D3240-11: Standard Test Method for Undissolved Water in Aviation Turbine Fuel, March 2011 6. MIL-DTL-5624V, Detail Specification...Impact of 50% Alcohol to Jet Blends on Aviation Turbine Fuel Coalescence - Navy Coalescence Test NF&LCFT REPORT 441/15-001 17 October 2014

  5. A small-scale test for fiber release from carbon composites. [pyrolysis and impact

    Science.gov (United States)

    Gilwee, W. J., Jr.; Fish, R. H.

    1980-01-01

    A test method was developed to determine relative fiber loss from pyrolyzed composites with different resins and fiber construction. Eleven composites consisting of woven and unwoven carbon fiber reinforcement and different resins were subjected to the burn and impact test device. The composites made with undirectional tape had higher fiber loss than those with woven fabric. Also, the fiber loss was inversely proportional to the char yield of the resin.

  6. Impact Foam Testing for Multi-Mission Earth Entry Vehicle Applications

    Science.gov (United States)

    Glaab, Louis J.; Agrawal, Paul; Hawbaker, James

    2013-01-01

    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, two different Rohacell foams were tested to determine their thermal conductivity in support of MMEEV design applications. These applications include thermal insulation during atmospheric entry, impact attenuation, and post-impact thermal insulation in support of thermal soak analysis. Results indicate that for these closed-cell foams, the effect of impact is limited on thermal conductivity due to the venting of the virgin material gas and subsequent ambient air replacement. Results also indicate that the effect of foam temperature is significant compared to data suggested by manufacturer's specifications.

  7. 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.

  8. 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

    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 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...

  9. High-speed impact test using an inertial mass and an optical interferometer.

    Science.gov (United States)

    Jin, T; Watanabe, K; Prayogi, I A; Takita, A; Mitatha, S; Djamal, M; Jia, H Z; Hou, W M; Fujii, Y

    2013-07-01

    A high-speed impact testing method for evaluating mechanical properties of materials is proposed using an inertial mass and a dual beat-frequencies laser Doppler interferometer (DB-LDI). In this method, an inertial mass levitated using an aerostatic linear bearing is made to collide with the material being tested at a high initial velocity. During the collision, the velocity of the mass, which is even higher than the critical velocity (±0.56 m/s) defined by the frequency difference of the Zeeman laser, is accurately measured using the DB-LDI. The position, acceleration, and impact force of the mass are calculated from the measured velocity. Using the proposed method, the mechanical properties of a visco-elastic material under a high-speed impact loading condition can be accurately evaluated.

  10. UTILIZATION OF ImPACT TESTING TO MEASURE INJURY RISK IN ALPINE SKI AND SNOWBOARD ATHLETES

    Science.gov (United States)

    Huntimer, Brittney; Kernozek, Thomas; Cole, John

    2016-01-01

    ABSTRACT Background While studies that have examined the prevalence of musculoskeletal injuries in alpine skiing and snowboarding exist, there has been no discussion of how neurocognitive deficits may influence such injuries. Recent authors have identified a possible link between Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) testing results and the prevalence of musculoskeletal injury in athletic populations. However, no study has specifically examined this in the alpine skiing and snowboard athletes who sustain injury and those that do not. Hypothesis/Purpose The purpose was to review injury data and ImPACT test results within the local ski/snowboard population to determine if there was a difference in components of ImPACT test scores between injured and non-injured athletes. It was hypothesized that differences would exist in component scores on ImPACT testing between injured and non-injured athletes. Study design Retrospective cohort study Methods Injury records and baseline ImPACT testing scores for 93 athletes aged 14-17 participating in a local ski and snowboard club during the 2009-2012 seasons were gathered retrospectively. Injuries documented for the lower and upper extremity included ligament sprains, muscle strains, contusions, dislocation/subluxation, fractures and concussions. Athletes who sustained any of these listed injuries were categorized within the injured athlete group. Each component of ImPACT test scores was compared between gender and for injury status within skiing and snowboarding disciplines using a series of two-way analysis of variance tests. Results There was no difference between non-injured and injured females as well as non-injured and injured males in reaction time and visual motor speed (VMS), however there was an interaction between gender and injury status on composite reaction time and visual motor speed, or VMS. The composite reaction time for females was 4.7% faster with injury while males without injury

  11. Mesoscopic analyses of porous concrete under static compression and drop weight impact tests

    DEFF Research Database (Denmark)

    Agar Ozbek, A.S.; Pedersen, R.R.; Weerheijm, J.;

    2008-01-01

    The failure process in highly porous concrete was analyzed experimentally and numerically. A triaxial visco-plastic damage model and a mesoscale representation of the material composition were considered to reproduce static compression and drop weight impact tests. In the mesoscopic model, concre...

  12. Using Tests To Evaluate the Impact of Curricular Reform on Higher Order Thinking.

    Science.gov (United States)

    Davis, Alan

    The dominant issues in considering the use of tests developed outside the classroom to measure the impact of curriculum reform on higher order thinking are reviewed by a panel interviewed for this discussion. Panel members are: (1) Stuart Kahl, (2) Robert Linn, (3) Senta A. Raizen, (4) Lauren Resnick, and (5) Thomas A. Romberg. It is conceded…

  13. Analysis of rear-end impact response using mathematical human modeling and volunteer tests

    NARCIS (Netherlands)

    Meijer, R.; Hoof, J.F.A.M. van; Ono, K.; Kaneoka, K.

    2001-01-01

    At TNO multi-directional mathematical human body models have been developed. The objective of this study was to simulate the rigid seat and standard seat JARI rear-impact sled tests using the MADYMO 50th percentile male model. The head and neck response of this human model and the volunteers were co

  14. 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.

  15. A Unified Theory of Impact Crises and Mass Extinctions: Quantitative Tests

    Science.gov (United States)

    Rampino, Michael R.; Haggerty, Bruce M.; Pagano, Thomas C.

    1997-01-01

    Several quantitative tests of a general hypothesis linking impacts of large asteroids and comets with mass extinctions of life are possible based on astronomical data, impact dynamics, and geological information. The waiting of large-body impacts on the Earth derive from the flux of Earth-crossing asteroids and comets, and the estimated size of impacts capable of causing large-scale environmental disasters, predict that impacts of objects greater than or equal to 5 km in diameter (greater than or equal to 10 (exp 7) Mt TNT equivalent) could be sufficient to explain the record of approximately 25 extinction pulses in the last 540 Myr, with the 5 recorded major mass extinctions related to impacts of the largest objects of greater than or equal to 10 km in diameter (greater than or equal to 10(exp 8) Mt Events). Smaller impacts (approximately 10 (exp 6) Mt), with significant regional environmental effects, could be responsible for the lesser boundaries in the geologic record.

  16. Asteroid Impact and Deflection Assessment mission: the Double Asteroid Redirection Test (DART)

    Science.gov (United States)

    Cheng, A.; Michel, P.

    2015-10-01

    The Asteroid Impact & Deflection Assessment (AIDA) mission will be the first space experiment to demonstrate asteroid impact hazard mitigation by using a kinetic impactor. AIDA is a joint ESA-NASA cooperative project, which includes the ESA Asteroid Impact Mission (AIM) rendezvous spacecraft and the NASA Double Asteroid Redirection Test (DART) mission. The AIDA target is the near-Earth binary asteroid 65803 Didymos, which will make an unusually close approach to Earth in October, 2022. The ~300-kg DART spacecraft is designed to impact the Didymos secondary at 6.5 km/s and demonstrate the ability to modify its trajectory through momentum transfer. The primary goals of AIDA are (i) to investigate the binary near-Earth asteroid (65803) Didymos, (ii) to demonstrate asteroid deflection by kinetic impact and to characterize the deflection. The primary DART objectives are to demonstrate a hypervelocity impact on the Didymos moon and to determine the resulting deflection from ground-based observatories. The DART impact on the Didymos secondary will cause a measurable change in the orbital period of the binary.

  17. Impact and hardness optimisation of composite materials inspired by the babassu nut (Orbignya speciosa).

    Science.gov (United States)

    Staufenberg, Gerrit; Graupner, Nina; Müssig, Jörg

    2015-08-20

    The babassu nut is the fruit of the babassu palm Orbignya speciosa. The combination of hardness and impact strength is difficult to acquire for artificial materials, making the babassu nut a promising source for biomimetic inspiration. Unnotched Charpy impact tests, Shore D hardness tests and scanning electron microscopy were used for mechanical and microscopical analysis of the pericarp. Four major principles were found for a biomimetic approach: a hard core ((1); endocarp) is embedded in a soft outer layer of high impact strength ((2); epicarp) and is reinforced with fibres of variable fineness (3), some of which are oriented radial to the core (4). Biomimetic fibre-reinforced composites were produced using abstracted mechanisms of the babassu nut based on regenerated cellulose fibres (lyocell, L) with two different fineness values as reinforcement embedded in a polylactide (PLA) core matrix and polypropylene (PP) based outer layers. The biomimetic fibre composite reaches a significantly higher impact strength that is 1.6 times higher than the reference sample produced from a PLA/PP/L-blend. At the same time the hardness is slightly increased compared to PP/L.

  18. 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.

  19. 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.

  20. 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...

  1. The impact of neurodynamic testing on the perception of experimentally induced muscle pain.

    Science.gov (United States)

    Coppieters, Michel W; Kurz, Kimberly; Mortensen, Thor Einar; Richards, Nicola L; Skaret, Ingrid A; McLaughlin, Laurie M; Hodges, Paul W

    2005-02-01

    Neurodynamic tests such as the straight leg raising (SLR) and slump test are frequently used for assessment of mechanosensitivity of neural tissues. However, there is ongoing debate in the literature regarding the contributions of neural and non-neural tissues to the elicited symptoms because many structures are affected by these tests. Sensitizing manoeuvres are limb or spinal movements added to neurodynamic tests, which aim to identify the origin of the symptoms by preferentially loading or unloading neural structures. A prerequisite for the use of sensitizing manoeuvres to identify neural involvement is that the addition of sensitizing manoeuvres has no impact on pain perception when the origin of the pain is non-neural. In this study, experimental muscle pain was induced by injection of hypertonic saline in tibialis anterior or soleus in 25 asymptomatic, naive volunteers. A first experiment investigated the impact of hip adduction, abduction, medial and lateral rotation in the SLR position. In a second experiment, the different stages of the slump test were examined. The intensity and area of experimentally induced muscle pain did not increase when sensitizing manoeuvres were added to the SLR or throughout the successive stages of the slump test. The findings of this study lend support to the validity of the use of sensitizing manoeuvres during neurodynamic testing.

  2. ACTUAL WASTE TESTING OF GYCOLATE IMPACTS ON THE SRS TANK FARM

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.

    2014-05-28

    Glycolic acid is being studied as a 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 and simulant testing, but several outstanding issues remained. This report documents the actual-waste tests to determine the impacts of glycolate on storage and evaporation of Savannah River Site high-level waste. The objectives of this study are to address the following: Determine the extent to which sludge constituents (Pu, U, Fe, etc.) dissolve (the solubility of sludge constituents) in the glycolate-containing 2H-evaporator feed. Determine the impact of glycolate on the sorption of fissile (Pu, U, etc.) components onto sodium aluminosilicate solids. The first objective was accomplished through actual-waste testing using Tank 43H and 38H supernatant and Tank 51H sludge at Tank Farm storage conditions. The second objective was accomplished by contacting actual 2H-evaporator scale with the products from the testing for the first objective. There is no anticipated impact of up to 10 g/L of glycolate in DWPF recycle to the Tank Farm on tank waste component solubilities as investigated in this test. Most components were not influenced by glycolate during solubility tests, including major components such as aluminum, sodium, and most salt anions. There was potentially a slight increase in soluble iron with added glycolate, but the soluble iron concentration remained so low (on the order of 10 mg/L) as to not impact the iron to fissile ratio in sludge. Uranium and plutonium appear to have been supersaturated in 2H-evaporator feed solution mixture used for this testing. As a result, there was a reduction of soluble uranium and plutonium as a function of time. The change in soluble uranium concentration was

  3. Assessing transportation infrastructure impacts on rangelands: test of a standard rangeland assessment protocol

    Science.gov (United States)

    Duniway, Michael C.; Herrick, Jeffrey E.; Pyke, David A.; Toledo, David

    2010-01-01

    Linear disturbances associated with on- and off-road vehicle use on rangelands has increased dramatically throughout the world in recent decades. This increase is due to a variety of factors including increased availability of all-terrain vehicles, infrastructure development (oil, gas, renewable energy, and ex-urban), and recreational activities. In addition to the direct impacts of road development, the presence and use of roads may alter resilience of adjoining areas through indirect effects such as altered site hydrologic and eolian processes, invasive seed dispersal, and sediment transport. There are few standardized methods for assessing impacts of transportation-related land-use activities on soils and vegetation in arid and semi-arid rangelands. Interpreting Indicators of Rangeland Health (IIRH) is an internationally accepted qualitative assessment that is applied widely to rangelands. We tested the sensitivity of IIRH to impacts of roads, trails, and pipelines on adjacent lands by surveying plots at three distances from these linear disturbances. We performed tests at 16 randomly selected sites in each of three ecosystems (Northern High Plains, Colorado Plateau, and Chihuahuan Desert) for a total of 208 evaluation plots. We also evaluated the repeatability of IIRH when applied to road-related disturbance gradients. Finally, we tested extent of correlations between IIRH plot attribute departure classes and trends in a suite of quantitative indicators. Results indicated that the IIRH technique is sensitive to direct and indirect impacts of transportation activities with greater departure from reference condition near disturbances than far from disturbances. Trends in degradation of ecological processes detected with qualitative assessments were highly correlated with quantitative data. Qualitative and quantitative assessments employed in this study can be used to assess impacts of transportation features at the plot scale. Through integration with remote

  4. 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.

  5. Rapid impact testing for quantitative assessment of large populations of bridges

    Science.gov (United States)

    Zhou, Yun; Prader, John; DeVitis, John; Deal, Adrienne; Zhang, Jian; Moon, Franklin; Aktan, A. Emin

    2011-04-01

    Although the widely acknowledged shortcomings of visual inspection have fueled significant advances in the areas of non-destructive evaluation and structural health monitoring (SHM) over the last several decades, the actual practice of bridge assessment has remained largely unchanged. The authors believe the lack of adoption, especially of SHM technologies, is related to the 'single structure' scenarios that drive most research. To overcome this, the authors have developed a concept for a rapid single-input, multiple-output (SIMO) impact testing device that will be capable of capturing modal parameters and estimating flexibility/deflection basins of common highway bridges during routine inspections. The device is composed of a trailer-mounted impact source (capable of delivering a 50 kip impact) and retractable sensor arms, and will be controlled by an automated data acquisition, processing and modal parameter estimation software. The research presented in this paper covers (a) the theoretical basis for SISO, SIMO and MIMO impact testing to estimate flexibility, (b) proof of concept numerical studies using a finite element model, and (c) a pilot implementation on an operating highway bridge. Results indicate that the proposed approach can estimate modal flexibility within a few percent of static flexibility; however, the estimated modal flexibility matrix is only reliable for the substructures associated with the various SIMO tests. To overcome this shortcoming, a modal 'stitching' approach for substructure integration to estimate the full Eigen vector matrix is developed, and preliminary results of these methods are also presented.

  6. Ductile tearing of crack-like defects during hydrostatic testing of pipes

    Energy Technology Data Exchange (ETDEWEB)

    Hippert, E.; Donato, G.V.P.; Teixeira, J.C.G.; Lima de, R.S. [Petrobras, Rio de Janeiro (Brazil)

    2004-07-01

    Although hydrostatic testing is widely used to monitor pipeline integrity, experimental studies have shown that flaw growth can occur during hydrostatic testing procedures. This study investigated the effect of pipeline hydrostatic testing on ductile crack growth of prior crack-like defects. Six segments of 3 m length API X60 steel pipes were tested. Each segment contained an electro-sparking erosion part-wall defects positioned both externally and internally on the base metal. Crack extension for external part-wall defects was monitored using an ultrasonic technique. Pipe resistance curves of applied load versus crack depth were obtained for each crack configuration. Laboratory curves were obtained from fracture mechanics tests pieces and then used to determine the initiation of stable extension of the applied load defects. It was observed that the level of crack tip constraint and triaxiality were similar to those experienced in real structures. It was suggested that single edge notch tensile (SET) specimens may be the most suitable specimens for predicting pipeline toughness behavior. A suitable parameter for estimating hydrostatic testing pressure was derived from values obtained during Charpy V-notch impact testing. It was concluded that future research will focus on the development of SET specimens and testing methods. 12 refs., 4 tabs., 11 figs.

  7. Spin Testing for Durability Began on a Self-Tuning Impact Damper for Turbomachinery Blades

    Science.gov (United States)

    Duffy, Kirsten; Mehmed, Oral

    2003-01-01

    NASA and Pratt & Whitney will collaborate under a Space Act Agreement to perform spin testing of the impact damper to verify damping effectiveness and durability. Pratt & Whitney will provide the turbine blade and damper hardware for the tests. NASA will provide the facility and perform the tests. Effectiveness and durability will be investigated during and after sustained sweeps of rotor speed through resonance. Tests of a platform wedge damper are also planned to compare its effectiveness with that of the impact damper. Results from baseline tests without dampers will be used to measure damping effectiveness. The self-tuning impact damper combines two damping methods-the tuned mass damper and the impact damper. It consists of a ball located within a cavity in the blade. This ball rolls back and forth on a spherical trough under centrifugal load (tuned mass damper) and can strike the walls of the cavity (impact damper). The ball s rolling natural frequency is proportional to the rotor speed and can be designed to follow an engine-order line (integer multiple of rotor speed). Aerodynamic forcing frequencies typically follow these engineorder lines, and a damper tuned to the engine order will most effectively reduce blade vibrations when the resonant frequency equals the engine-order forcing frequency. This damper has been tested in flat plates and turbine blades in the Dynamic Spin Facility. During testing, a pair of plates or blades rotates in vacuum. Excitation is provided by one of three methods--eddy-current engine-order excitation (ECE), electromechanical shakers, and magnetic bearing excitation. The eddy-current system consists of magnets located circumferentially around the rotor. As a blade passes a magnet, a force is imparted on the blade. The number of magnets used can be varied to change the desired engine order of the excitation. The magnets are remotely raised or lowered to change the magnitude of the force on the blades. The other two methods apply

  8. Impact Testing on Reinforced Carbon-Carbon Flat Panels with Ice Projectiles for the Space Shuttle Return to Flight Program

    Science.gov (United States)

    Melis, Matthew E.; Revilock, Duane M.; Pereira, Michael J.; Lyle, Karen H.

    2009-01-01

    Following the tragedy of the Orbiter Columbia (STS-107) on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the space shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize reinforced carbon-carbon (RCC) along with ice and foam debris materials, which could shed on ascent and impact the orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS-DYNA (Livermore Software Technology Corp.) to predict damage by potential and actual impact events on the orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: Level 1--fundamental tests to obtain independent static and dynamic constitutive model properties of materials of interest, Level 2--subcomponent impact tests to provide highly controlled impact test data for the correlation and validation of the models, and Level 3--full-scale orbiter leading-edge impact tests to establish the final level of confidence for the analysis methodology. This report discusses the Level 2 test program conducted in the NASA Glenn Research Center (GRC) Ballistic Impact Laboratory with ice projectile impact tests on flat RCC panels, and presents the data observed. The Level 2 testing consisted of 54 impact tests in the NASA GRC Ballistic Impact Laboratory on 6- by 6-in. and 6- by 12-in. flat plates of RCC and evaluated three types of debris projectiles: Single-crystal, polycrystal, and "soft" ice. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile and validated the use of the ice and RCC models for use in LS-DYNA.

  9. SCK-CEN Contribution to the''Relation between different measures of exposure-induced shifts in ductile-brittle transition temperatures'' (REFEREE). Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R.; Van Walle, E.; Fabry, A.; Puzzolante, J.L

    1998-08-01

    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.

  10. Sport helmet design and virtual impact test by image-based finite element modeling.

    Science.gov (United States)

    Luo, Yunhua; Liang, Zhaoyang

    2013-01-01

    Head injury has been a major concern in various sports, especially in contact sports such as football and ice hockey. Helmet has been adopted as a protective device in such sports, aiming at preventing or at least alleviating head injuries. However, there exist two challenges in current helmet design and test. One is that the helmet does not fit the subject's head well; the other is that current helmet testing methods are not able to provide accurate information about intracranial pressure and stress/strain level in brain tissues during impact. To meet the challenges, an image-based finite element modeling procedure was proposed to design subject-specific helmet and to conduct virtual impact test. In the procedure, a set of medical images such as computed tomography (CT) and magnetic resonance image (MRI) of the subject's head was used to construct geometric shape of the helmet and to develop a helmet-head finite element model that can be used in the virtual impact test.

  11. 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.

  12. 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.

  13. Tests on impact effect of partial fracture at steel frame connections

    Institute of Scientific and Technical Information of China (English)

    Yiyi CHEN; Ruoning BIAN; Fangfang LIAO

    2008-01-01

    Impact effect of sudden fracture at steel frame connections under severe earthquake or other extreme loads is presented in this paper. The relation of impulse caused by structural fracture to the release of inner force at the cracked location, the magnitude of the response to impact on the basis of one degree of freedom model, and the ratio of the peak value of response to natural period of the system are investigated. Two types of fracture tests were designed and carried out both on uniaxial steel bar tensioned and moment resistant steel frame model. It is proven that the response during the fracture process can be measured quite well using high-frequency data proces-sing system. It is also revealed that the instant fracture of structural connection is characterized by progressive and partial fracture. Numerical evaluation of the impact effect of connection fracture is carried out.

  14. Mechanical resistance of UO{sub 2} pellet by means of free-fall-impact testing

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Tae-sik; Lee, Seung-jae; Kim, Jae-ik; Jo, Young-ho; Park, Bo-yong; Ko, Sang-ern [KEPCO NF, Daejeon (Korea, Republic of)

    2014-10-15

    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 UO{sub 2} 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 UO{sub 2} 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 UO{sub 2} 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 UO{sub 2}. 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

  15. Evaluating the impact of genotype errors on rare variant tests of association.

    Science.gov (United States)

    Cook, Kaitlyn; Benitez, Alejandra; Fu, Casey; Tintle, Nathan

    2014-01-01

    The new class of rare variant tests has usually been evaluated assuming perfect genotype information. In reality, rare variant genotypes may be incorrect, and so rare variant tests should be robust to imperfect data. Errors and uncertainty in SNP genotyping are already known to dramatically impact statistical power for single marker tests on common variants and, in some cases, inflate the type I error rate. Recent results show that uncertainty in genotype calls derived from sequencing reads are dependent on several factors, including read depth, calling algorithm, number of alleles present in the sample, and the frequency at which an allele segregates in the population. We have recently proposed a general framework for the evaluation and investigation of rare variant tests of association, classifying most rare variant tests into one of two broad categories (length or joint tests). We use this framework to relate factors affecting genotype uncertainty to the power and type I error rate of rare variant tests. We find that non-differential genotype errors (an error process that occurs independent of phenotype) decrease power, with larger decreases for extremely rare variants, and for the common homozygote to heterozygote error. Differential genotype errors (an error process that is associated with phenotype status), lead to inflated type I error rates which are more likely to occur at sites with more common homozygote to heterozygote errors than vice versa. Finally, our work suggests that certain rare variant tests and study designs may be more robust to the inclusion of genotype errors. Further work is needed to directly integrate genotype calling algorithm decisions, study costs and test statistic choices to provide comprehensive design and analysis advice which appropriately accounts for the impact of genotype errors.

  16. 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.

  17. 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.

  18. Testing impact attenuation on California playground surfaces made of recycled tires.

    Science.gov (United States)

    Vidair, Charles; Haas, Robert; Schlag, Robert

    2007-12-01

    This study was conducted to determine whether rubberized playground surfaces made of recycled tires comply with state-mandated standards for impact attenuation (measured with an accelerometer), and whether their properties change in response to temperature or time. The Head Impact Criterion (HIC) standard of 1000 was found to be a more sensitive indicator of compliance than the G(max) standard of 200(g). Of 32 playgrounds tested, 22 (69 percent) failed the HIC standard. As the heights of playground structures increased, so did the likelihood that the rubberized surface below would fail the HIC standard. Rubberized surfaces gave stable readings for the first three months following installation, and higher values in response to increasing surface temperature. An excessively high percentage of playground surfaces made of recycled tires failed the state-mandated standards designed to prevent serious head injury from falls. Future failures might be prevented by requiring installers to perform post-installation testing to verify compliance.

  19. 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.

  20. 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.

  1. IMPACT TESTING OF MATERIALS USING AN EIGHT-INCH AIR GUN AND COMPUTER REDUCTION OF DATA

    Energy Technology Data Exchange (ETDEWEB)

    Thorne, L. F.

    1973-10-01

    A mechanical shock actuator has been converted into an air gun capable of firing 8-inch-·diameter (20.32 cm) projectiles to velocities exceeding 1000 fps (304.8 m/ s). This new capability has been used to study the effect of impact velocity upon the energy.absorbed by crushable materials. Shockpulse data is reduced by computer techniques and test results are displayed in either tabular or graphic format by use of the C DC 6600 Calcomp plotter.

  2. Accountability and Teacher Practice: Investigating the Impact of a New State Test and the Timing of State Test Adoption on Teacher Time Use

    Science.gov (United States)

    Cocke, Erin F.; Buckley, Jack; Scott, Marc A.

    2011-01-01

    There is much debate over the impact of high stakes testing as well as a growing body of research focused on both the intended and unintended consequences of these tests. One claim of both the popular media and education researchers is that high stakes tests have led to curricular narrowing--the idea that school time is increasingly allocated to…

  3. Impact of BRCA1/2 testing and disclosure of a positive test result on women affected and unaffected with breast or ovarian cancer

    NARCIS (Netherlands)

    van Roosmalen, MS; Stalmeier, PFM; Verhoef, LCG; Hoekstra-Weebers, JEHM; Oosterwijk, JC; Hoogerbrugge, N; Moog, U; van Daal, WAJ

    2004-01-01

    To evaluate the impact of BRCA1/2 testing and disclosure of a positive test result on women affected and unaffected with cancer. Longitudinal cohort study including women affected and unaffected with breast or ovarian cancer testing for a BRCA1/2 mutation. Data on well-being (anxiety, depression, ca

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    P R B Kozowyk

    Full Text Available 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.

  6. 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.

  7. 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.

  8. 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.

  9. Risk assessment test for lead bioaccessibility to waterfowl in mine-impacted soils

    Science.gov (United States)

    Furman, O.; Strawn, D.G.; Heinz, G.H.; Williams, B.

    2006-01-01

    Due to variations in soil physicochemical properties, species physiology, and contaminant speciation, Pb toxicity is difficult to evaluate without conducting in vivo dose-response studies. Such tests, however, are expensive and time consuming, making them impractical to use in assessment and management of contaminated environments. One possible alternative is to develop a physiologically based extraction test (PBET) that can be used to measure relative bioaccessibility. We developed and correlated a PBET designed to measure the bioaccessibility of Pb to waterfowl (W-PBET) in mine-impacted soils located in the Coeur d'Alene River Basin, Idaho. The W-PBET was also used to evaluate the impact of P amendments on Pb bioavailability. The W-PBET results were correlated to waterfowl-tissue Pb levels from a mallard duck [Anas platyrhynchos (L.)] feeding study. The W-PBET Pb concentrations were significantly less in the P-amended soils than in the unamended soils. Results from this study show that the W-PBET can be used to assess relative changes in Pb bioaccessibility to waterfowl in these mine-impacted soils, and therefore will be a valuable test to help manage and remediate contaminated soils.

  10. 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.

  11. 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.

  12. Water Impact Test and Simulation of a Composite Energy Absorbing Fuselage Section

    Science.gov (United States)

    Fasanella, Edwin L.; Jackson, Karen E.; Sparks, Chad; Sareen, Ashish

    2003-01-01

    In March 2002, a 25-ft/s vertical drop test of a composite fuselage section was conducted onto water. The purpose of the test was to obtain experimental data characterizing the structural response of the fuselage section during water impact for comparison with two previous drop tests that were performed onto a rigid surface and soft soil. For the drop test, the fuselage section was configured with ten 100-lb. lead masses, five per side, that were attached to seat rails mounted to the floor. The fuselage section was raised to a height of 10-ft. and dropped vertically into a 15-ft. diameter pool filled to a depth of 3.5-ft. with water. Approximately 70 channels of data were collected during the drop test at a 10-kHz sampling rate. The test data were used to validate crash simulations of the water impact that were developed using the nonlinear, explicit transient dynamic codes, MSC.Dytran and LS-DYNA. The fuselage structure was modeled using shell and solid elements with a Lagrangian mesh, and the water was modeled with both Eulerian and Lagrangian techniques. The fluid-structure interactions were executed using the fast general coupling in MSC.Dytran and the Arbitrary Lagrange-Euler (ALE) coupling in LS-DYNA. Additionally, the smooth particle hydrodynamics (SPH) meshless Lagrangian technique was used in LS-DYNA to represent the fluid. The simulation results were correlated with the test data to validate the modeling approach. Additional simulation studies were performed to determine how changes in mesh density, mesh uniformity, fluid viscosity, and failure strain influence the test-analysis correlation.

  13. 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

  14. Determination of peak deflections from human surrogates using chestbands in side impact tests.

    Science.gov (United States)

    Yoganandan, Narayan; Humm, John R; Pintar, Frank A; Maiman, Dennis J

    2013-08-01

    To understand the biomechanics of the human body in motor vehicle environments, physical models including anthropomorphic test devices (ATD) and biological models (postmortem human surrogates) are used, and sled tests are conducted. Deflection is often used as a biomechanical variable to characterize the effects of impact loading and derive injury criteria. The objective of the present study was to evaluate different techniques and recommend a methodology to determine the peak thorax and abdominal deflections from temporal contours using chestbands in oblique lateral impacts. The side impact ATD WorldSID representing human surrogates was positioned on a seat. The seat was rigidly fixed to the platform of an acceleration sled. The oblique load-wall fixed to the sled consisted of separate and adjustable plates to contact the shoulder, thorax, abdomen, and pelvis. Two 59-gage chestbands were wrapped on the thorax and abdomen. Tests were conducted at low, medium, and high velocities (3.4, 6.7, and 7.5m/s) and three methods, termed the spine-sternum, bilateral, and spine-box, were used to determine the global peak deflection and its angulation. Results indicated that all three methods produced very similar angulations, for all velocity tests, and at both thorax and abdominal regions. However, maximum deflections were the lowest in the spine-sternum, followed by bilateral and spine-box methods, with one exception. Based on the development of deflection contours, locations used in the definitions of the origin, and accuracy in identifying critical locations/points in time-varying contours, results of the present study indicate that the bilateral method is the optimum procedure to determine the oblique peak deflection vector in biomechanical tests.

  15. The WRAIR projectile concussive impact model of mild traumatic brain injury: re-design, testing and preclinical validation.

    Science.gov (United States)

    Leung, Lai Yee; Larimore, Zachary; Holmes, Larry; Cartagena, Casandra; Mountney, Andrea; Deng-Bryant, Ying; Schmid, Kara; Shear, Deborah; Tortella, Frank

    2014-08-01

    The WRAIR projectile concussive impact (PCI) model was developed for preclinical study of concussion. It represents a truly non-invasive closed-head injury caused by a blunt impact. The original design, however, has several drawbacks that limit the manipulation of injury parameters. The present study describes engineering advancements made to the PCI injury model including helmet material testing, projectile impact energy/head kinematics and impact location. Material testing indicated that among the tested materials, 'fiber-glass/carbon' had the lowest elastic modulus and yield stress for providing an relative high percentage of load transfer from the projectile impact, resulting in significant hippocampal astrocyte activation. Impact energy testing of small projectiles, ranging in shape and size, showed the steel sphere produced the highest impact energy and the most consistent impact characteristics. Additional tests confirmed the steel sphere produced linear and rotational motions on the rat's head while remaining within a range that meets the criteria for mTBI. Finally, impact location testing results showed that PCI targeted at the temporoparietal surface of the rat head produced the most prominent gait abnormalities. Using the parameters defined above, pilot studies were conducted to provide initial validation of the PCI model demonstrating quantifiable and significant increases in righting reflex recovery time, axonal damage and astrocyte activation following single and multiple concussions.

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

    CERN Document Server

    Geng, Jia-Jia; Zhang, Xin

    2014-01-01

    The Sandage-Loeb (SL) test is a unique method to probe dark energy in the "redshift desert" of $2\\lesssim z\\lesssim 5$, and thus it provides an important supplement to the other dark energy probes. Therefore, it is of great importance to quantify how the future SL 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 $\\Omega_m$ 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 d...

  17. 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.

  18. Tensile and impact properties of V-4Cr-4Ti alloy heats 832665 and 832864.

    Energy Technology Data Exchange (ETDEWEB)

    Bray, T. S.; Tsai, H.; Nowicki, L. J.; Billone, M. C.; Smith, D. L.; Johnson, W. R.; Trester, P. W.

    1999-11-08

    Two large heats of V-4Cr-4Ti alloy were produced in the United States in the past few years. The first, 832665, was a 500 kg heat procured by the U.S. Department of Energy for basic fusion structural materials research. The second, 832864, was a 1300 kg heat procured by General Atomics for the DIII-D radiative divertor upgrade. Both heats were produced by Oremet-Wah Chang (previously Teledyne Wah Chang of Albany). Tensile properties up to 800 C and Charpy V-notch impact properties down to liquid nitrogen temperature were measured for both heats. The product forms tested for both heats were rolled sheets annealed at 1000 C for 1 h in vacuum. Testing results show the behavior of the two heats to be similar and the reduction of strengths with temperature to be insignificant up to at least 750 C. Ductility of both materials is good in the test temperature range. Impact properties for both heats are excellent--no brittle failures at temperatures above -150 C. Compared to the data for previous smaller laboratory heats of 15-50 kg, the results show that scale-up of vanadium alloy ingot production to sizes useful for reactor blanket design can be successfully achieved as long as reasonable process control is implemented.

  19. Testing, Modeling and System Impact of Metabolic Heat Regenerated Temperature Swing Adsorption

    Science.gov (United States)

    Lacomini, Christine S.; Powers, Aaron; Lewis, Matthew; Linrud, Christopher; Waguespack, Glenn; Conger, Bruce; Paul, Heather L.

    2008-01-01

    Metabolic heat regenerated temperature swing adsorption (MTSA) technology is being developed for removal and rejection of carbon dioxide (CO2) and heat from a portable life support system (PLSS) to the Martian environment. Previously, hardware was built and tested to demonstrate using heat from simulated, dry ventilation loop gas to affect the temperature swing required to regenerate an adsorbent used for CO2 removal. New testing has been performed using a moist, simulated ventilation loop gas to demonstrate the effects of water condensing and freezing in the heat exchanger during adsorbent regeneration. In addition, thermal models of the adsorbent during regeneration were modified and calibrated with test data to capture the effect of the CO2 heat of desorption. Finally, MTSA impact on PLSS design was evaluated by performing thermal balances assuming a specific PLSS architecture. Results using NASA s Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT), a PLSS system evaluation tool, are presented.

  20. Impact of the emergence of designer drugs upon sports doping testing.

    Science.gov (United States)

    Teale, P; Scarth, J; Hudson, S

    2012-01-01

    Historically, dope-testing methods have been developed to target specific and known threats to the integrity of sport. Traditionally, the source of new analytical targets for which testing was required were derived almost exclusively from the pharmaceutical industry. More recently, the emergence of designer drugs, such as tetrahydrogestrinone that are specifically intended to evade detection, or novel chemicals intended to circumvent laws controlling the sale and distribution of recreational drugs, such as anabolic steroids, stimulants and cannabinoids, have become a significant issue. In this review, we shall consider the emergence of designer drugs and the response of dope-testing laboratories to these new threats, in particular developments in analytical methods, instrumentation and research intended to detect their abuse, and we consider the likely future impact of these approaches.

  1. 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.

  2. 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.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Kosiński P.

    2015-02-01

    Full Text Available 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.

  5. Experimental and numerical analysis of Izod impact test of cortical bone tissue

    Science.gov (United States)

    Abdel-Wahab, A. A.; Silberschmidt, V. V.

    2012-05-01

    Bones can only sustain loads until a certain limit, beyond which they fail. Usually, the reasons for bone fracture are traumatic falls, sports injuries, and engagement in transport or industrial accidents. A proper treatment of bones and prevention of their fracture can be supported by in-depth understanding of deformation and fracture behavior of this tissue in such dynamic events. In this paper, a combination of experimental and numerical analysis was carried out in order to comprehend the fracture behavior of cortical bone tissue. Experimental tests were performed to study the transient dynamic behavior of cortical bone tissue under impact bending loading. The variability of absorbed energy for different cortex positions and notch depths was studied using Izod impact tests. Also, Extended Finite-Element Method implemented into the commercial finite-element software Abaqus was used to simulate the crack initiation and growth processes in a cantilever beam of cortical bone exposed to impact loading using the Izod loading scheme. The simulation results show a good agreement with the experimental data.

  6. 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.

  7. Irradiation programme HFR phase IIb - SPICE. Impact testing on up to 16.3 dpa irradiated RAFM steels. Final report for task TW2-TTMS 001b-D05

    Energy Technology Data Exchange (ETDEWEB)

    Gaganidze, E.; Dafferner, B.; Ries, H.; Rolli, R.; Schneider, H.C.; Aktaa, J.

    2008-04-15

    The objective of this work is to study the effects of neutron irradiation on the embrittlement behavior of different reduced activation ferritic/martensitic (RAFM) steels. The irradiation was carried out in the Petten High Flux Reactor (HFR) in the framework of the HFR Phase IIb (SPICE) irradiation project at a nominal dose of 16.3 dpa and at different irradiation temperatures (250-450 C). The impact properties are investigated by instrumented Charpy-V tests with subsize specimens (KLST-type). The emphasis is put on the investigation of irradiation induced embrittlement and hardening of the European RAFM reference steel for the first wall of a DEMO fusion reactor, EURO- FER97 under different heat treatment conditions. The mechanical properties of EUROFER97 are compared with the results on international reference steels (F82H-mod, OPTIFER-Ia, GA3X and MANET-I) included in the SPICE project. EUROFER97 irradiated up to 16.3 dpa between 250 and 450 C showed irradiation resistance that is comparable to those of best RAFM steels. Large low temperature (T{sub irr} {<=} 300 C) embrittlement is seen for all investigated RAFM steels. Heat treatment of EUROFER97 at higher austenitizing temperature led to the reduction of embrittlement at low temperatures (T{sub irr} {<=} 350 C). At T{sub irr} {>=} 350 C the DBTTs of the steels remain below -20 C and, hence, are well below the application temperature. Analysis of hardening vs. embrittlement behaviour indicated hardening dominated embrittlement at T{sub irr} {<=} 350 C with 0.17 {<=} C{sub 100} {<=} 0.53 C/MPa. Oxygen dispersion hardened ODS EUROFER with 0.5 wt.% Y{sub 2}O{sub 3} has been irradiated at selected irradiation temperatures. ODS EUROFER showed not satisfying impact properties already in the unirradiated condition characterized by low USE = 2.54 J and large DBTT = 135 C. Furthermore, the increase of USE for irradiation temperatures below T{sub irr} {<=} 350 C indicates not optimized fabrication process. At T{sub irr

  8. Factors impacting nanoindentation testing results of the cuticle of dung beetle Copris ochus Motschulsky

    Institute of Scientific and Technical Information of China (English)

    TONG Jin; SUN Ji-yu; CHEN Dong-hui; ZHANG Shu-jun

    2004-01-01

    The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball.Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors impacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 20 s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time.There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is △h = 54.834 52 ln(0.007 23t +1.004 86), where, △h is the depth increment at the maximum load and t is the time.

  9. Numerical modeling and analysis of the mechanism of a novel shock wave regulator for impact test

    Institute of Scientific and Technical Information of China (English)

    Wang Gongxian; Zhang Zhiyi; Wang Yu

    2008-01-01

    Based on the concept of hydraulic dissipation of kinetic energy, a novel shock wave regulator, which is composed of a damper and an externally triggered valve, is presented with thorough analyses on its working mechanism. By establishing motion equations of each component of the regulator and simulating the dynamic behavior of the whole system, the shock wave regulator is demonstrated numerically to be able to change the width and amplitude of shock pulses. Prompt and easy adjustment can be achieved by changing the equivalent flow area of damping orifices and consequently the closing velocity of the flow area of a valve, which makes it applicable to different impact testing.

  10. Impact of the Psychological Testing Assessment System (SATEPSI) for Scientific Publications in Psychological Assessment

    OpenAIRE

    Mansur-Alves,Marcela; Silva, Renata Saldanha; Fernandes,Sthefanie Carvalho de Ávila

    2016-01-01

    Abstract The strengthening of psychological assessment in Brazil in the twenty-first century can be understood as a result of the foundation of Psychological Test Evaluation System (SATEPSI, its Portuguese acronym) by Resolution 02/2003 of the Federal Council of Psychology. In this sense, the present study aimed to describe the impact of SATEPSI for research in the area. A survey of Brazilian researchers' publications was conducted in two periods in SciELO and BVS-Psi databases - 1993-2002 an...

  11. Vehicle Impact Testing of Snow Roads at McMurdo Station, Antarctica

    Science.gov (United States)

    2014-06-01

    McMurdo Station, Antarctica Co ld R eg io ns R es ea rc h an d En gi ne er in g La bo ra to ry Sally A. Shoop, Margaret A. Knuth, Wendy L...Vehicle Impact Testing of Snow Roads at McMurdo Station, Antarctica Sally A. Shoop, Margaret A. Knuth, and Monica Preston Cold Regions Research and...kilograms ERDC/CRREL TR-14-9 xii ERDC/CRREL TR-14-9 1 1 Introduction 1.1 Issue McMurdo Station, Antarctica , has approximately 20 miles (32 km

  12. An experimental study of the self-healing behavior of ionomeric systems under ballistic impact tests

    Science.gov (United States)

    Grande, A. M.; Coppi, S.; Di Landro, L.; Sala, G.; Giacomuzzo, C.; Francesconi, A.; Rahman, M. A.

    2012-04-01

    This research deals with the investigation of the self-healing behavior after ballistic damage of ethylene-methacrylic acid ionomers and theirs blends with epoxidized natural rubber (ENR). The self-healing capability was studied by ballistic puncture tests under different experimental conditions as sample thickness, bullet speed, diameter and shape. Bullet speed ranging from few hundreds meters per second to few km/s were employed. The healing efficiency was evaluated by applying a pressure gradient trough the plates and by checking for possible flow at the damage zone. A morphology analysis of the impact area was made observing all samples by scanning electron microscope.

  13. 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

  14. 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.

  15. HIV testing and counselling in Estonian prisons, 2012 to 2013: aims, processes and impacts.

    Science.gov (United States)

    Kivimets, K; Uuskula, A

    2014-11-27

    We present data from an observational cohort study on human immunodeficiency virus (HIV) prevention and control measures in prisons in Estonia to assess the potential for HIV transmission in this setting. HIV testing and retesting data from the Estonian prison health department were used to estimate HIV prevalence and incidence in prison. Since 2002, voluntary HIV counselling and testing has routinely been offered to all prisoners and has been part of the new prisoners health check. At the end of 2012, there were 3,289 prisoners in Estonia, including 170 women: 28.5% were drug users and 15.6% were infected with HIV. Of the HIV-positive inmates, 8.3% were newly diagnosed on prison entry. In 2012, 4,387 HIV tests (including retests) were performed in Estonian prisons. Among 1,756 initially HIV-negative prisoners who were in prison for more than one year and therefore tested for HIV twice within 12 months (at entry and annual testing), one new HIV infection was detected, an incidence of 0.067 per 100 person-years (95% confidence interval (CI): 0.025–5.572). This analysis indicates low risk of HIV transmission in Estonian prisons. Implementation of HIV management interventions could impact positively on the health of prisoners and the communities to which they return.

  16. Effects of manufacturing process on impact properties and microstructures of ODS steels

    Energy Technology Data Exchange (ETDEWEB)

    Tanno, Takashi, E-mail: tanno.takashi@jaea.go.jp; Ohtsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji; Tanaka, Kenya

    2014-12-15

    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)

  17. Impact Toughness Properties of Nickel- and Manganese-Free High Nitrogen Austenitic Stainless Steels

    Science.gov (United States)

    Mohammadzadeh, Roghayeh; Akbari, Alireza; Mohammadzadeh, Mina

    2016-12-01

    A large amount of manganese (>10 wt pct) in nickel-free high nitrogen austenitic stainless steels (Ni-free HNASSs) can induce toxicity. In order to develop Ni-free HNASSs with low or no manganese, it is necessary to investigate their mechanical properties for biomedical applications. This work aims to study the Charpy V-notch (CVN) impact toughness properties of a Ni- and Mn-free Fe-22.7Cr-2.4Mo-1.2N HNASS plate in the temperature range of 103 K to 423 K (-170 °C to 150 °C). The results show that unlike conventional AISI 316L austenitic stainless steel, the Ni- and Mn-free HNASS exhibits a sharp ductile-to-brittle transition (DBT). The intergranular brittle fracture associated with some plasticity and deformation bands is observed on the fracture surface at 298 K (25 °C). Electron backscattered diffraction (EBSD) analysis of the impact-tested sample in the longitudinal direction indicates that deformation bands are parallel to {111} slip planes. By decreasing the temperature to 273 K, 263 K, and 103 K (0 °C, -10 °C, and -70 °C), entirely intergranular brittle fracture occurs on the fracture surface. The fracture mode changes from brittle fracture to ductile as the temperature increases to 423 K (150 °C). The decrease in impact toughness is discussed on the basis of temperature sensitivity of plastic flow and planarity of deformation mechanism.

  18. Numerical Evaluation of a Light-Gas Gun Facility for Impact Test

    Directory of Open Access Journals (Sweden)

    C. Rahner

    2014-01-01

    Full Text Available Experimental tests which match the application conditions might be used to properly evaluate materials for specific applications. High velocity impacts can be simulated using light-gas gun facilities, which come in different types and complexities. In this work different setups for a one-stage light-gas gun facility have been numerically analyzed in order to evaluate their suitability for testing materials and composites used as armor protection. A maximal barrel length of 6 m and a maximal reservoir pressure of a standard industrial gas bottle (20 MPa were chosen as limitations. The numerical predictions show that it is not possible to accelerate the projectile directly to the desired velocity with nitrogen, helium, or hydrogen as propellant gas. When using a sabot corresponding to a higher bore diameter, the necessary velocity is achievable with helium and hydrogen gases.

  19. What's in a Name? The Impact of Accurate Staphylococcus pseudintermedius Identification on Appropriate Antimicrobial Susceptibility Testing.

    Science.gov (United States)

    Limbago, Brandi M

    2016-03-01

    Bacteria in the Staphylococcus intermedius group, including Staphylococcus pseudintermedius, often encode mecA-mediated methicillin resistance. Reliable detection of this phenotype for proper treatment and infection control decisions requires that these coagulase-positive staphylococci are accurately identified and specifically that they are not misidentified as S. aureus. As correct species level bacterial identification becomes more commonplace in clinical laboratories, one can expect to see changes in guidance for antimicrobial susceptibility testing and interpretation. The study by Wu et al. in this issue (M. T. Wu, C.-A. D. Burnham, L. F. Westblade, J. Dien Bard, S. D. Lawhon, M. A. Wallace, T. Stanley, E. Burd, J. Hindler, R. M. Humphries, J Clin Microbiol 54:535-542, 2016, http://dx.doi.org/10.1128/JCM.02864-15) highlights the impact of robust identification of S. intermedius group organisms on the selection of appropriate antimicrobial susceptibility testing methods and interpretation.

  20. Validating material modelling for OFHC copper using dynamic tensile extrusion (DTE) test at different velocity impact

    Science.gov (United States)

    Bonora, N.; Testa, G.; Ruggiero, A.; Iannitti, G.; Colliander, M. Hörnquist; Mortazavi, N.

    2017-01-01

    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 the modified Rusinek-Klepaczko model, are presented. Simulation of microstructure evolution was performed using the visco-plastic self consistent model (VPSC), providing, as input, the velocity gradient history obtained with FEM at selected locations along the axis of the fragment trapped in the extrusion die. Finally, results are compared with EBSD analysis.

  1. Assessing the impact of differential genotyping errors on rare variant tests of association.

    Science.gov (United States)

    Mayer-Jochimsen, Morgan; Fast, Shannon; Tintle, Nathan L

    2013-01-01

    Genotyping errors are well-known to impact the power and type I error rate in single marker tests of association. Genotyping errors that happen according to the same process in cases and controls are known as non-differential genotyping errors, whereas genotyping errors that occur with different processes in the cases and controls are known as differential genotype errors. For single marker tests, non-differential genotyping errors reduce power, while differential genotyping errors increase the type I error rate. However, little is known about the behavior of the new generation of rare variant tests of association in the presence of genotyping errors. In this manuscript we use a comprehensive simulation study to explore the effects of numerous factors on the type I error rate of rare variant tests of association in the presence of differential genotyping error. We find that increased sample size, decreased minor allele frequency, and an increased number of single nucleotide variants (SNVs) included in the test all increase the type I error rate in the presence of differential genotyping errors. We also find that the greater the relative difference in case-control genotyping error rates the larger the type I error rate. Lastly, as is the case for single marker tests, genotyping errors classifying the common homozygote as the heterozygote inflate the type I error rate significantly more than errors classifying the heterozygote as the common homozygote. In general, our findings are in line with results from single marker tests. To ensure that type I error inflation does not occur when analyzing next-generation sequencing data careful consideration of study design (e.g. use of randomization), caution in meta-analysis and using publicly available controls, and the use of standard quality control metrics is critical.

  2. Enhancement of Impact Toughness by Delamination Fracture in a Low-Alloy High-Strength Steel with Al Alloying

    Science.gov (United States)

    Sun, Junjie; Jiang, Tao; Liu, Hongji; Guo, Shengwu; Liu, Yongning

    2016-12-01

    The effect of delamination toughening of martensitic steel was investigated both at room and low temperatures [253 K and 233 K (-20 °C and -40 °C)]. Two low-alloy martensitic steels with and without Al alloying were both prepared. Layered structure with white band and black matrix was observed in Al alloyed steel, while a homogeneous microstructure was displayed in the steel without Al. Both steels achieved high strength (tensile strength over 1600 MPa) and good ductility (elongation over 11 pct), but they displayed stark contrasts on impact fracture mode and Charpy impact energy. Delamination fracture occurred in Al alloyed steel and the impact energies were significantly increased both at room temperature (from 75 to 138 J, i.e., nearly improved up to 2 times) and low temperatures [from 47.9 to 71.3 J at 233 K (-40 °C)] compared with the one without Al. Alloying with Al promotes the segregation of Cr, Mn, Si and C elements to form a network structure, which is martensite with higher carbon content and higher hardness than that of the matrix. And this network structure evolved into a band structure during the hot rolling process. The difference of yield stress between the band structure and the matrix gives rise to a delamination fracture during the impact test, which increases the toughness greatly.

  3. Enhancement of Impact Toughness by Delamination Fracture in a Low-Alloy High-Strength Steel with Al Alloying

    Science.gov (United States)

    Sun, Junjie; Jiang, Tao; Liu, Hongji; Guo, Shengwu; Liu, Yongning

    2016-09-01

    The effect of delamination toughening of martensitic steel was investigated both at room and low temperatures [253 K and 233 K (-20 °C and -40 °C)]. Two low-alloy martensitic steels with and without Al alloying were both prepared. Layered structure with white band and black matrix was observed in Al alloyed steel, while a homogeneous microstructure was displayed in the steel without Al. Both steels achieved high strength (tensile strength over 1600 MPa) and good ductility (elongation over 11 pct), but they displayed stark contrasts on impact fracture mode and Charpy impact energy. Delamination fracture occurred in Al alloyed steel and the impact energies were significantly increased both at room temperature (from 75 to 138 J, i.e., nearly improved up to 2 times) and low temperatures [from 47.9 to 71.3 J at 233 K (-40 °C)] compared with the one without Al. Alloying with Al promotes the segregation of Cr, Mn, Si and C elements to form a network structure, which is martensite with higher carbon content and higher hardness than that of the matrix. And this network structure evolved into a band structure during the hot rolling process. The difference of yield stress between the band structure and the matrix gives rise to a delamination fracture during the impact test, which increases the toughness greatly.

  4. Effects of Zr, Ti, and Al Additions on Nonmetallic Inclusions and Impact Toughness of Cast Low-Alloy Steel

    Science.gov (United States)

    Bizyukov, Pavel V.; Giese, Scott R.

    2017-03-01

    A microalloying of the low-carbon and low-alloy cast steel was conducted with Zr, Ti, and Al that were added to the steel in four combinations. After heat treatment, the samples were tested for impact toughness at room temperature using the Charpy method. The highest values of impact toughness were obtained in the group treated with Zr, while Zr-Ti and Zr-Ti-Al groups showed moderate toughness values; the lowest values were observed in the Zr-Al group. Difference among the treatment groups was observed in the fracture mechanisms, morphology, and area distribution of the inclusions. High toughness values achieved in the trials treated with zirconium corresponded with smooth ductile fracture. The metal treated with a combination of zirconium and titanium had a relatively small area occupied by inclusions, but its toughness was also moderate. Lowest impact toughness values corresponded with the larger area occupied by the inclusions in the trials treated with aluminum. Also, a connection between the solubility product [Al][N] and impact toughness was established. The study also provides a qualitative description and quantitative analysis of the nonmetallic inclusions formation as a result of microalloying treatment. The precipitation sequence of the inclusions was described based on the thermochemical calculations for the nonmetallic compounds discovered in the experimental steel. A description of the size distribution, morphology, and composition was conducted for the oxides, nitrides, sulfides, and multiphase particles.

  5. Exploratory behaviour in the open field test adapted for larval zebrafish: impact of environmental complexity.

    Science.gov (United States)

    Ahmad, Farooq; Richardson, Michael K

    2013-01-01

    This study aimed to develop and characterize a novel (standard) open field test adapted for larval zebrafish. We also developed and characterized a variant of the same assay consisting of a colour-enriched open field; this was used to assess the impact of environmental complexity on patterns of exploratory behaviours as well to determine natural colour preference/avoidance. We report the following main findings: (1) zebrafish larvae display characteristic patterns of exploratory behaviours in the standard open field, such as thigmotaxis/centre avoidance; (2) environmental complexity (i.e. presence of colours) differentially affects patterns of exploratory behaviours and greatly attenuates natural zone preference; (3) larvae displayed the ability to discriminate colours. As reported previously in adult zebrafish, larvae showed avoidance towards blue and black; however, in contrast to the reported adult behaviour, larvae displayed avoidance towards red. Avoidance towards yellow and preference for green and orange are shown for the first time, (4) compared to standard open field tests, exposure to the colour-enriched open field resulted in an enhanced expression of anxiety-like behaviours. To conclude, we not only developed and adapted a traditional rodent behavioural assay that serves as a gold standard in preclinical drug screening, but we also provide a version of the same test that affords the possibility to investigate the impact of environmental stress on behaviour in larval zebrafish while representing the first test for assessment of natural colour preference/avoidance in larval zebrafish. In the future, these assays will improve preclinical drug screening methodologies towards the goal to uncover novel drugs. This article is part of a Special Issue entitled: insert SI title.

  6. Impact of body composition on performance in fitness tests among personnel of the Croatian navy.

    Science.gov (United States)

    Sporis, Goran; Jukić, Igor; Bok, Daniel; Vuleta, Dinko; Harasin, Drazen

    2011-06-01

    The purpose of this study was to determine the impact of body weight on fitness tests among the personnel of the Croatian navy. Forty two naval personnel (age 27 +/- 4.1 years; body mass 86.2 +/- 4.9 kg; height 184.6 +/- 7.4 cm; body fat percentage 17.3 +/- 5.2) participated in this study. In order to evaluate the fitness of the naval servicemen, we applied a testing procedure that included measurements of 7 fitness tests and 15 body anthropometric tests. A negative correlation was found between the body fat percentage and all the analyzed sprint tests and three anaerobic power tests (r), SP5 (r = -0.42), SP10 (r = -0.51), SP20 (r = -0.53), SJ (r = -0.45), CM (r = -0.57), SLJ (r = -0.67). Also a negative correlation was found between the body fat percentage and VO2(max) (r = -0.44). A positive correlation was found between the sprint test and the power performance test and thigh and calf girth. Spiriting ability is influenced by the strength of a person. This is one of the reasons why we found a positive correlation between the sprint test (SP5, SP10 and SP20) and thigh and calf girth. In this study we found a negative correlation between body fat percentages and all the sprint tests and three anaerobic power tests and VO2(max). The ectomorph somatotypes have positive correlations with all variables. The mesomorph somatotypes have the greatest positive correlations with all variables. The endomorph somatotypes have negative correlations with all variables. According to the body composition of Croatian naval servicemen we can conclude that they need a sufficient level of strength and endurance for everyday tasks. The effectiveness of a weight-management program is determined by the success of the participants in losing the necessary amount of weight and being able to maintain that weight loss. This requires long-term tracking of these individuals in a naval environment.

  7. 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

  8. Design and testing of miniaturized plasma sensor for measuring hypervelocity impact plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Goel, A., E-mail: ashish09@stanford.edu; Tarantino, P. M.; Lauben, D. S.; Close, S. [Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305 (United States)

    2015-04-15

    An increasingly notable component of the space environment pertains to the impact of meteoroids and orbital debris on spacecraft and the resulting mechanical and electrical damages. Traveling at speeds of tens of km/s, when these particles, collectively referred to as hypervelocity particles, impact a satellite, they vaporize, ionize, and produce a radially expanding plasma that can generate electrically harmful radio frequency emission or serve as a trigger for electrostatic discharge. In order to measure the flux, composition, energy distribution, and temperature of ions and electrons in this plasma, a miniaturized plasma sensor has been developed for carrying out in-situ measurements in space. The sensor comprises an array of electrostatic analyzer wells split into 16 different channels, catering to different species and energy ranges in the plasma. We present results from numerical simulation based optimization of sensor geometry. A novel approach of fabricating the sensor using printed circuit boards is implemented. We also describe the test setup used for calibrating the sensor and show results demonstrating the energy band pass characteristics of the sensor. In addition to the hypervelocity impact plasmas, the plasma sensor developed can also be used to carry out measurements of ionospheric plasma, diagnostics of plasma propulsion systems, and in other space physics experiments.

  9. Design and testing of miniaturized plasma sensor for measuring hypervelocity impact plasmas

    Science.gov (United States)

    Goel, A.; Tarantino, P. M.; Lauben, D. S.; Close, S.

    2015-04-01

    An increasingly notable component of the space environment pertains to the impact of meteoroids and orbital debris on spacecraft and the resulting mechanical and electrical damages. Traveling at speeds of tens of km/s, when these particles, collectively referred to as hypervelocity particles, impact a satellite, they vaporize, ionize, and produce a radially expanding plasma that can generate electrically harmful radio frequency emission or serve as a trigger for electrostatic discharge. In order to measure the flux, composition, energy distribution, and temperature of ions and electrons in this plasma, a miniaturized plasma sensor has been developed for carrying out in-situ measurements in space. The sensor comprises an array of electrostatic analyzer wells split into 16 different channels, catering to different species and energy ranges in the plasma. We present results from numerical simulation based optimization of sensor geometry. A novel approach of fabricating the sensor using printed circuit boards is implemented. We also describe the test setup used for calibrating the sensor and show results demonstrating the energy band pass characteristics of the sensor. In addition to the hypervelocity impact plasmas, the plasma sensor developed can also be used to carry out measurements of ionospheric plasma, diagnostics of plasma propulsion systems, and in other space physics experiments.

  10. 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.

  11. IMPACT ANALYSES AND TESTS OF CONCRETE OVERPACKS OF SPENT NUCLEAR FUEL STORAGE CASKS

    Directory of Open Access Journals (Sweden)

    SANGHOON LEE

    2014-02-01

    Full Text Available 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 [1], 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.

  12. 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

  13. Internally damped, self-arresting vertical drop-weight impact test apparatus

    Science.gov (United States)

    Ambur, Damodar R. (Inventor); Prasad, Chunchu B. (Inventor); Stockum, Robert W. (Inventor)

    1996-01-01

    A vertical dropped-weight impact test machine has a dropped-weight barrel vertically supported on upper and lower support brackets. The dropped-weight barrel is chambered to receive a dropped-weight assembly having a latch pin at its upper end, a damping unit in the middle, and a tup at its lower end. The tup is adapted for gathering data during impact testing. The latch pin releasably engages a latch pin coupling assembly. The latch pin coupling assembly is attached to a winch via a halyard for raising and lowering the dropped-weight assembly. The lower end of the dropped-weight barrel is provided with a bounce-back arresting mechanism which is activated by the descending passage of the dropped-weight assembly. After striking the specimen, the dropped-weight assembly rebounds vertically and is caught by the bounce-back arresting mechanism. The damping unit of the dropped-weight assembly serves to dissipate energy from the rebounding dropped-weight assembly and prevents the dropped-weight assembly from rebounding from the self-arresting mechanism.

  14. 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.

  15. A new method for testing pile by single-impact energy and P-S curve

    Science.gov (United States)

    Xu, Zhao-Yong; Duan, Yong-Kang; Wang, Bin; Hu, Yi-Li; Yang, Run-Hai; Xu, Jun; Zhao, Jin-Ming

    2004-11-01

    By studying the pile-formula and stress-wave methods ( e.g., CASE method), the authors propose a new method for testing piles using the single-impact energy and P-S curves. The vibration and wave figures are recorded, and the dynamic 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 (total energy), the consumed energy of wave motion and vibration and so on, the vertical bearing capacity for single pile is 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, the dynamic 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 pile body can be judged from the formation of P-S curves.

  16. 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…

  17. CHARACTERISATION OF EPOXY BASED E-GLASS / CARBON REINFORCED POLYMER COMPOSITE LAMINATES SUBJECTED TO LOW VELOCITY IMPACT TEST (DROP WEIGHT

    Directory of Open Access Journals (Sweden)

    Dr.H.K.SHIVANAND

    2013-05-01

    Full Text Available 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.

  18. A 3D-psoriatic skin model for dermatological testing: The impact of culture conditions

    Directory of Open Access Journals (Sweden)

    Alexandra Duque-Fernandez

    2016-12-01

    Full Text Available Inadequate representation of the human tissue environment during a preclinical screen can result in inaccurate predictions of compound effects. Consequently, pharmaceutical investigators are searching for preclinical models that closely resemble original tissue for predicting clinical outcomes.The current research aims to compare the impact of using serum-free medium instead of complete culture medium during the last step of psoriatic skin substitute reconstruction. Skin substitutes were produced according to the self-assembly approach.Serum-free conditions have no negative impact on the reconstruction of healthy or psoriatic skin substitutes presented in this study regarding their macroscopic or histological appearances. ATR-FTIR results showed no significant differences in the CH2 bands between psoriatic substitutes cultured with or without serum, thus suggesting that serum deprivation did not have a negative impact on the lipid organization of their stratum corneum. Serum deprivation could even lead to a better organization of healthy skin substitute lipids. Percutaneous analyses demonstrated that psoriatic substitutes cultured in serum-free conditions showed a higher permeability to hydrocortisone compared to controls, while no significant differences in benzoic acid and caffeine penetration profiles were observed.Results obtained with this 3D-psoriatic skin substitute demonstrate the potential and versatility of the model. It could offer good prediction of drug related toxicities at preclinical stages performed in order to avoid unexpected and costly findings in the clinic.Together, these findings offer a new approach for one of the most important challenges of the 21st century, namely, prediction of drug toxicity.•Impact of serum-free conditions during psoriatic skin substitutes reconstruction.•Lipids disorganization of healthy and psoriatic skin substitutes.•Permeation profiles of healthy skin substitutes.•Permeation profiles of

  19. 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.

  20. 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...

  1. Genetic testing for Lynch syndrome in the first year of colorectal cancer: a review of the psychological impact.

    Science.gov (United States)

    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 between January 1997 and October 2007 on the psychological impact of (1) CRC-diagnosis up to 1 year after treatment and of (2) genetic testing for Lynch syndrome in patients with CRC. Studies on the psychological impact of genetic testing in newly diagnosed patient with CRC were not available. Either CRC patients diagnosed several years ago were studied and the focus was also often on the psychological impact of genetic testing prior to DNA-test disclosure. They show that limitations in emotional and social functioning can persist up to 1 year after CRC treatment, especially in those with a stoma or diagnosed before age 60. Female patients and male patients diagnosed before age 50 appear to be more vulnerable to genetic test-related distress. It is well known that being treated for CRC has great impact on psychological functioning. Little is known about the psychological impact during the first year after diagnosis and very little is known about the additional psychological effect of genetic testing for hereditary cancer in this period. We found presumptive evidence that specific subgroups of patients with CRC are more vulnerable for genetic-testing-related distress.

  2. 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.

  3. Cyclist kinematics in car impacts reconstructed in simulations and full scale testing with Polar dummy

    NARCIS (Netherlands)

    Schijndel-de Nooij, M. van; Hair-Buijssen, S.H.H.M. de; Rodarius, C.; Fredriksson, R.

    2012-01-01

    For the development of effective vehicle-related safety solutions to improve cyclist and pedestrian protection, essential information on impact locations, impact situations and cyclist and pedestrian kinematics in impacts with passenger cars is fundamental. Accidentology research showed that cyclist

  4. Situation and context impacts the expression of personality: the influence of breeding season and test context.

    Science.gov (United States)

    Haage, Marianne; Bergvall, Ulrika A; Maran, Tiit; Kiik, Kairi; Angerbjörn, Anders

    2013-11-01

    Non-human animal personality is defined as consistent behavioural differences across time and situations/contexts. Behaviours are, however, often plastic and to explain how plasticity and personality may coexist an adaptive framework has been developed. Still, there is little information on how personality is impacted by situations and contexts on an individual level. We investigated this in the European mink (Mustela lutreola) by performing a set of five experiments in two situations consisting of non-breeding and breeding season, and by using different test contexts. Three personality trait domains were identified; boldness, exploration and sociability. The levels of boldness and exploration changed between seasons but remained repeatable, which implies behavioural reaction norms and supports that the concept of personality remained applicable despite plasticity. Whilst males became bolder and more explorative in the breeding season females became shyer, which reflects European mink breeding behaviour. Furthermore, behaviours performed in mirror stimulus tests fell into different domains depending on whether, the test was conducted in the own territory or not, suggesting plasticity in the response towards conspecifics. To conclude, our results highlight the importance of situation and context for the expression of personality, and the significance of measuring multiple personality trait domains with several methods.

  5. 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.

  6. Impact of a Routine, Opt-Out HIV Testing Program on HIV Testing and Case Detection in North Carolina Sexually-Transmitted Disease Clinics

    Science.gov (United States)

    Klein, Pamela W.; Messer, Lynne C.; Myers, Evan R.; Weber, David J.; Leone, Peter A.; Miller, William C.

    2016-01-01

    The impact of routine, opt-out HIV testing programs in clinical settings is inconclusive. The objective of this study was to estimate the impact of an expanded, routine HIV testing program in North Carolina sexually transmitted disease (STD) clinics on HIV testing and case detection. Adults aged 18–64 who received an HIV test in a North Carolina STD clinic July 1, 2005 through June 30, 2011 were included in this analysis, dichotomized at the date of implementation on November 1, 2007. HIV testing and case detection counts and rates were analyzed using interrupted time series analysis, and Poisson and multilevel logistic regression. Pre-intervention, 426 new HIV-infected cases were identified from 128,029 tests (0.33%), whereas 816 new HIV-infected cases were found from 274,745 tests post-intervention (0.30%). Pre-intervention, HIV testing increased by 55 tests per month (95% confidence interval [CI]: 41, 72), but only 34 tests per month (95% CI: 26, 42) post-intervention. Increases in HIV testing rates were most pronounced in females and non-Hispanic whites. A slight pre-intervention decline in case detection was mitigated by the intervention (mean difference [MD]=0.01; 95% CI: −0.02, 0.05). Increases in case detection rates were observed among females and non-Hispanic blacks. The impact of a routine HIV screening in North Carolina STD clinics was marginal, with the greatest benefit among persons not traditionally targeted for HIV testing. The use of a pre-intervention comparison period identified important temporal trends that otherwise would have been ignored. PMID:24825338

  7. Application of a PVDF-based stress gauge in determining dynamic stress-strain curves of concrete under impact testing

    Science.gov (United States)

    Meng, Yi; Yi, Weijian

    2011-06-01

    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.

  8. Subtask 12D1: Impact properties of production heat of V-4Cr-4Ti

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Nowicki, L.; Smith, D.L. [Argonne National Lab., IL (United States)

    1995-03-01

    Following previous reports of excellent properties of a laboratory heat of V-4Cr-4Ti, the alloy identified as the primary vanadium-based candidate for application as fusion reactor structural components, a large production-scale (500-kg) heat of the alloy was fabricated successfully. Since impact toughness has been known to be most sensitive to alloy composition and microstructure, impact testing of the production-scale heat was conducted in this work between -200{degrees}C and +200{degrees}C. A 500-kg heat of V-4Cr-4Ti, an alloy identified previously as the primary vanadium-based candidate alloy for application as fusion reactor structural components, has been produced successfully. Impact tests were conducted at -196{degrees}C to 150{degrees}C on 1/3-size Charpy specimens of the scale-up heat in as-rolled condition and after annealing for 1 h at 950, 1000, and 1050{degrees}C in high-quality vacuum. The annealed material remained ductile at all test temperatures; the ductile-brittle transition temperature (DBTT) was lower than -200{degrees}C. The upper-shelf energy of the production-scale heat was similar to that of the laboratory-scale ({approx}30-kg) heat of V-4Cr-4Ti investigated previously. Effect of annealing temperature was not significant; however, annealing at 1000{degrees}C for 1 h not only produces best impact properties but also ensures a sufficient tolerance to effect of temperature inhomogeneity expected when annealing large components. Effect of notch geometry was also investigated on the production heat. When annealed properly (e.g., at 1000{degrees}C for 1 h), impact properties were not sensitive to notch geometry (45{degrees}-notch, root radius 0.25 mm; and 300-notch, root radius 0.08 mm). 11 refs., 6 figs., 1 tab.

  9. Testing the potential for improving quality of sediments impacted by mussel farms using bioturbating polychaete worms

    DEFF Research Database (Denmark)

    Bergström, Per; Carlsson, Marita S; Lindegarth, Mats;

    2015-01-01

    Biodeposits from farmed mussels severely influence the biogeochemistry of sediments by increasing the levels of organic matter (OM). Mitigation of such negative impacts is important for the development of sustainable aquaculture operations. As a step towards developing methods for remediation...... of coastal sediments affected by mussel farming, the effects of the polychaete, Hediste diversicolor was evaluated experimentally. In a series of field- and laboratory experiments we tested hypotheses about the effects of polychaetes on sediment oxygen consumption, nutrient fluxes and sulphide pools under...... of OM. The accumulation of pore water sulphides were reduced and fluxes of nutrients across the sediment-water interface increased. Additional calculations suggest that the effects of polychaetes were mainly indirect and driven by increased microbial activity due to the borrowing activity...

  10. Impact Properties of Engineered Cementitious Composites with High Volume Fly Ash Using SHPB Test

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhitao; YANG Yingzi; YAO Yan

    2012-01-01

    The split Hopkinson pressure bar (SHPB) testing with diameter 40 mm was used to investigate the dynamic mechanical properties of engineered cementitious composites (ECCs) with different fly ash content.The basic properties including deformation,energy absorption capacity,strain-stress relationship and failure patterns were discussed.The ECCs showed strain-rate dependency and kept better plastic flow during impact process compared with reactive powder concrete (RPC) and concrete,but the critical compressive strength was lower than that of R-PC and concrete.The bridging effect of PVA fiber and addition of fly ash can significantly improve the deformation and energy absorption capacities of ECCs.With the increase of fly ash content in ECCs,the static and dynamic compressive strength lowered and the dynamic increase factor enhanced,Therefore,to meet different engineering needs,the content of fly ash can be an important index to control the static and dynamic mechanical properties of ECCs.

  11. Testing and modeling of damages in composite laminates subject to low velocity impact

    Directory of Open Access Journals (Sweden)

    Al-Hadrayi Ziadoon M. R, Zhang Yunlai, Zhou Chuwei

    2016-01-01

    Full Text Available In recent years, composite materials were used extensively in the most important industries, especially in aerospace industries and aircraft structures due to its high strength, high stiffness, resistance of corrosion, and lightweight. The problem is how to choose the perfect design for composite laminates. And study the effects of modeling of the stacking sequences of composite laminates on failure modes (delamination, matrix cracking, and fiber failure under the test of low velocity impact. This paper has validating to the experimental results that has published. The composite used was carbon fiber /epoxy (CFRE, (UD ASTM/D6641 as three groups [A, B, C]. It had same material system. The difference was only in stacking sequences as random design. These models were simulated numerically by the commercial software implemented into the FEM/ABAQUS 6.9.1 with subroutine file (VUMAT a user-define 3D damage model. The results had good agreement with experimental results.

  12. 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.

  13. Cannabinoids & Stress: impact of HU-210 on behavioral tests of anxiety in acutely stressed mice.

    Science.gov (United States)

    Kinden, Renee; Zhang, Xia

    2015-05-01

    Anxiety disorders are one of the most prevalent classes of mental disorders affecting the general population, but current treatment strategies are restricted by their limited efficacy and side effect profiles. Although the cannabinoid system is speculated to be a key player in the modulation of stress responses and emotionality, the vast majority of current research initiatives had not incorporated stress exposure into their experimental designs. This study was the first to investigate the impact of exogenous cannabinoid administration in an acutely stressed mouse model, where CD1 mice were pre-treated with HU-210, a potent CB1R agonist, prior to acute stress exposure and subsequent behavioral testing. Exogenous cannabinoid administration induced distinct behavioral phenotypes in stressed and unstressed mice. While low doses of HU-210 were anxiolytic in unstressed subjects, this effect was abolished when mice were exposed to an acute stressor. The administration of higher HU-210 doses in combination with acute stress exposure led to severe locomotor deficits that were not previously observed at the same dose in unstressed subjects. These findings suggest that exogenous cannabinoids and acute stress act synergistically in an anxiogenic manner. This study underlies the importance of including stress exposure into future anxiety-cannabinoid research due to the differential impact of cannabinoid administration on stressed and unstressed subjects.

  14. Impact testing of the residual limb: System response to changes in prosthetic stiffness

    Directory of Open Access Journals (Sweden)

    Erin Boutwell, PhD

    2016-04-01

    Full Text Available Currently, it is unknown whether changing prosthetic limb stiffness affects total limb stiffness and/or influences the shock absorption of an individual with transtibial amputation. The hypotheses tested within this study are that a decrease in longitudinal prosthetic stiffness will produce (1 reduced total limb stiffness and (2 reduced magnitude of peak impact forces and increased time delay to peak force. Fourteen subjects with a transtibial amputation participated in this study. Prosthetic stiffness was modified by means of a shock-absorbing pylon that provides reduced longitudinal stiffness through compression of a helical spring within the pylon. A sudden loading evaluation device was built to examine changes in limb loading mechanics during a sudden impact event. No significant change was found in the peak force magnitude or timing of the peak force between prosthetic limb stiffness conditions. Total limb stiffness estimates ranged from 14.9 to 17.9 kN/m but were not significantly different between conditions. Thus, the prosthetic-side total limb stiffness was unaffected by changes in prosthetic limb stiffness. The insensitivity of the total limb stiffness to prosthetic stiffness may be explained by the mechanical characteristics (i.e., stiffness and damping of the anatomical tissue within the residual limb.

  15. 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.

  16. 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.

  17. 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.

  18. Impact of clinical awareness and diagnostic tests on the underdiagnosis of Clostridium difficile infection.

    Science.gov (United States)

    Alcalá, L; Reigadas, E; Marín, M; Martín, A; Catalán, P; Bouza, E

    2015-08-01

    A multicenter study of Clostridium difficile infection (CDI) performed during 2008 in Spain revealed that two of every three episodes went undiagnosed or were misdiagnosed owing to nonsensitive diagnostic tests or lack of clinical suspicion and request. Since then, efforts have been made to improve the diagnostic tests used by laboratories and to increase the awareness of this disease among both clinicians and microbiologists. Our objective was to evaluate the impact of these efforts by assessing the current magnitude of underdiagnosis of CDI in Spain using two point-prevalence studies performed on one day each in January and July of 2013. A total of 111 Spanish laboratories selected all unformed stool specimens received for microbiological diagnosis on these days, and toxigenic culture was performed at a central reference laboratory. Toxigenic isolates were characterized both pheno- and genotypically. The reference laboratory detected 103 episodes of CDI in patients aged 2 years or more. Half (50.5 %) of the episodes were not diagnosed in the participating laboratories, owing to insensitive diagnostic tests (15.5 %) or the lack of clinical suspicion and request (35.0 %). The main ribotypes were 014, 078/126, 001/072, and 106. Ribotype 027 caused 2.9 % of all cases. Despite all the interventions undertaken, CDI remains a highly neglected disease because of the lack of sensitive diagnostic tests in some institutions and, especially, the absence of clinical suspicion, mainly in patients with community-associated CDI. Toxigenic C. difficile should be routinely sought in unformed stools sent for microbiological diagnosis, regardless of their origin.

  19. Neurocognitive performance and symptom profiles of Spanish-speaking Hispanic athletes on the ImPACT test.

    Science.gov (United States)

    Ott, Summer; Schatz, Philip; Solomon, Gary; Ryan, Joseph J

    2014-03-01

    This study documented baseline neurocognitive performance of 23,815 athletes on the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test. Specifically, 9,733 Hispanic, Spanish-speaking athletes who completed the ImPACT test in English and 2,087 Hispanic, Spanish-speaking athletes who completed the test in Spanish were compared with 11,955 English-speaking athletes who completed the test in English. Athletes were assigned to age groups (13-15, 16-18). Results revealed a significant effect of language group (p speaking athletes completing the test in Spanish scored more poorly than Spanish-speaking and English-speaking athletes completing the test in English, on all Composite scores and Total Symptom scores. Spanish-speaking athletes completing the test in English also performed more poorly than English-speaking athletes completing the test in English on three Composite scores. These differences in performance and reported symptoms highlight the need for caution in interpreting ImPACT test data for Hispanic Americans.

  20. Characteristic of retained austenite decomposition during tempering and its effect on impact toughness in SA508 Gr.3 steel

    Science.gov (United States)

    Yan, Guanghua; Han, Lizhan; Li, Chuanwei; Luo, Xiaomeng; Gu, Jianfeng

    2017-01-01

    Retained austenite(RA) usually presents in the quenched Nuclear Pressure-Vessel SA508 Gr.3 steel. In the present work, the characteristic of RA decomposition and its effect on the impact toughness were investigated by microstructure observation, dilatometric experiments and Charpy impact tests. The results show that the RA transformed into martensite and bainite during tempering at 230 °C and 400 °C respectively, while mixture of long rod carbides and ferrite formed at 650 °C. The long rod carbides formed from RA decomposition decrease the critical cleavage stress for initiation of micro-cracks, and deteriorate the impact toughness of the steel. Pre-tempering at a low temperature such as 230 °C or 400 °C leading to the decomposition of RA into martensite or baintie can eliminate the deterioration of the toughness caused by direct decomposition into long rod carbides. The absorbed energy indicate that pre-tempering at 400 °C can drive dramatically improvement in the toughness of the steel.

  1. Study on impact properties of creep-resistant steel thermally simulated heat affected zone

    Directory of Open Access Journals (Sweden)

    Mitrović Radivoje M.

    2012-01-01

    Full Text Available The steam pipe line (SPL and steam line material, along with its welded joints, subject to damage that accumulates during operation in coal power plants. As a result of thermal fatigue, dilatation of SPL at an operating temperature may lead to cracks initiation at the critical zones within heat affected zone (HAZ of steam pipe line welded joints. By registration of thermal cycle during welding and subsequent HAZ simulation is possible to obtain target microstructure. For the simulation is chosen heat resisting steel, 12H1MF (designation 13CrMo44 according to DIN standard. From the viewpoint of mechanical properties, special attention is on impact toughness mostly because very small number of available references. After simulation of single run and multi run welding test on instrumented Charpy pendulum. Metallographic and fractographic analysis is also performed, on simulated 12H1MF steel from service and new, unused steel. The results and correlation between microstructure and impact toughness is discussed, too.

  2. Comparison of Test Directions for Ability Tests: Impact on Young English-Language Learner and Non-ELL Students

    Science.gov (United States)

    Lakin, Joni Marie

    2010-01-01

    Ability tests play an important role in the assessment programs of many schools. However, the inferences about ability made from such tests presume that students understand the tasks they are attempting. Task familiarity can vary by student as well as by format. By design, nonverbal reasoning tests use formats that are intended to be novel. The…

  3. Experimental Testing of Rockfall Barriers Designed for the Low Range of Impact Energy

    Science.gov (United States)

    Buzzi, O.; Spadari, M.; Giacomini, A.; Fityus, S.; Sloan, S. W.

    2013-07-01

    Most of the recent research on rockfall and the development of protective systems, such as flexible rockfall barriers, have been focused on medium to high levels of impacting energy. However, in many regions of the world, the rockfall hazard involves low levels of energy. This is particularly the case in New South Wales, Australia, because of the nature of the geological environments. The state Road and Traffic Authority (RTA) has designed various types of rockfall barriers, including some of low capacity, i.e. 35 kJ. The latter were tested indoors using a pendulum equipped with an automatic block release mechanism triggered by an optical beam. Another three systems were also tested, including two products designed by rockfall specialised companies and one modification of the initial design of the RTA. The research focused on the influence of the system's stiffness on the transmission of load to components of the barrier such as posts and cables. Not surprisingly, the more compliant the system, the less loaded the cables and posts. It was also found that removing the intermediate cables and placing the mesh downslope could reduce the stiffness of the system designed by the RTA. The paper concludes with some multi-scale considerations on the capacity of a barrier to absorb the energy based on experimental evidence.

  4. Impact

    NARCIS (Netherlands)

    Lohse, Detlef; Bergmann, Raymond; Mikkelsen, Rene; Zeilstra, Christiaan; Meer, van der Devaraj; Versluis, Michel

    2004-01-01

    A lot of information on impacts of solid bodies on planets has been extracted from remote observations of impact craters on planetary surfaces; experiments however with large enough impact energies as compared to the energy stored in the ground are difficult. We approach this problem by downscaled e

  5. 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.

  6. 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...

  7. 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

  8. 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

  9. 78 FR 69943 - Anthropomorphic Test Devices; Q3s 3-Year-Old Child Side Impact Test Dummy, Incorporation by...

    Science.gov (United States)

    2013-11-21

    ... depth and the waist circumference (both larger in the Q3s). As compared to a human, the Q3s torso is... 161 173 174 +1 Chest depth 122 122 151 +24 Chest circumference, axilla 508 505 523 +4 Waist... restraints to limit the risk of head and chest injury to children in a side impact. We are considering...

  10. Simulation analysis of impact tests of steel plate reinforced concrete and reinforced concrete slabs against aircraft impact and its validation with experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq, Muhammad, E-mail: muhammad.sadiq@pnra.org [Center for Nuclear Safety (CNS), Pakistan Nuclear Regulatory Authority (PNRA), PO Box 1912, Islamabad (Pakistan); Xiu Yun, Zhu, E-mail: lyzhuxiuyun@163.com [Nuclear and Radiation Safety Center (NSC), Ministry of Environmental Protection (MEP), Beijing (China); Rong, Pan, E-mail: panrong@chinansc.cn [Nuclear and Radiation Safety Center (NSC), Ministry of Environmental Protection (MEP), Beijing (China)

    2014-07-01

    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.

  11. Evaluating the impact of hemp food consumption on workplace drug tests.

    Science.gov (United States)

    Leson, G; Pless, P; Grotenhermen, F; Kalant, H; ElSohly, M A

    2001-01-01

    Foods containing seeds or oil of the hemp plant (Cannabis sativa L.) are increasingly found in retail stores in the U.S. The presence of delta9-tetrahydrocannabinol (THC) in these foods has raised concern over their impact on the results of workplace drug tests for marijuana. Previous studies have shown that eating hemp foods can cause screening and confirmed positive results in urine specimens. This study evaluated the impact of extended daily ingestion of THC via hemp oil on urine levels of its metabolite 11-nor-9-carboxy-delta9-tetrahydrocannabinol (THC-COOH) for four distinct daily THC doses. Doses were representative of THC levels now commonly found in hemp seed products and a range of conceivable daily consumption rates. Fifteen THC-naïve adults ingested, over four successive 10-day periods, single daily THC doses ranging from 0.09 to 0.6 mg. Subjects self-administered THC in 15-mL aliquots (20 mL for the 0.6-mg dose) of four different blends of hemp and canola oils. Urine specimens were collected prior to the first ingestion of oil, on days 9 and 10 of each of the four study periods, and 1 and 3 days after the last ingestion. All specimens were screened for cannabinoids by radioimmunoassay (Immunalysis Direct RIA Kit), confirmed for THC-COOH by gas chromatography-mass spectrometry (GC-MS), and analyzed for creatinine to identify dilute specimens. None of the subjects who ingested daily doses of 0.45 mg of THC screened positive at the 50-ng/mL cutoff. At a daily THC dose of 0.6 mg, one specimen screened positive. The highest THC-COOH level found by GC-MS in any of the specimens was 5.2 ng/mL, well below the 15-ng/mL confirmation cutoff used in federal drug testing programs. A THC intake of 0.6 mg/day is equivalent to the consumption of approximately 125 mL of hemp oil containing 5 microg/g of THC or 300 g of hulled seeds at 2 microg/g. These THC concentrations are now typical in Canadian hemp seed products. Based on our findings, these concentrations appear

  12. 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 motivations. The possibility of a positive test result might have led those with personal history of 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.

  13. 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.

  14. 声振检测方法的发展%Evolution of the Acoustic Impact Testing Method

    Institute of Scientific and Technical Information of China (English)

    邬冠华; 林俊明; 任吉林; 周昌智

    2011-01-01

    依据激励方式的不同,分别从敲击检测和声阻检测方法两个方面对声振检测方法进行了介绍.敲击检测方法主要分整体振动检测法(或车轮敲击法)和局部振动检测法(或硬币敲击法),声阻检测法主要分机械阻抗法和局部共振检测法.声振检测方法尽管很早以前就已经出现了,但至今主要还停留在经验性的应用层面.对各种声振检测方法的基本原理及其发展作简要论述,希望起到抛砖引玉的作用,吸引业界关注该方法发展和应用的同仁共同来推进它的技术进步.%The acoustic impact testing method is presented with two different excitation methods: the tap testing method and the acoustic impedance testing method.The tap testing method includes the whole vibration testing (wheel-tap test) method and the local vibration testing method( coin-tap test), and the acoustic impedance method has the mechanical impedance method and the local resonance testing method.Though the acoustic impact testing method has a long history in testing activities, most concerns of this method are only restricted in its experiential applications.Here, the principals and their developments of several branches of the acoustic impact testing method are covered, with the main purpose to improve this old but effective method with the help of the people who concern its development and applications.

  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

    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

  16. The impact of the orbital decay of the LAGEOS satellites on the frame-dragging tests

    CERN Document Server

    Iorio, Lorenzo

    2016-01-01

    The laser-tracked geodetic satellites LAGEOS, LAGEOS II and LARES are currently employed, among other things, to measure the general relativistic Lense-Thirring effect in the gravitomagnetic field of the spinning Earth with the hope of providing a more accurate test of such a prediction of the Einstein's theory of gravitation than the existing ones. The secular decay $\\dot a$ of the semimajor axes $a$ of such spacecrafts, recently measured in an independent way to a $\\sigma_{\\dot a}\\approx 0.1-0.01$ m yr$^{-1}$ accuracy level, may indirectly impact the proposed relativistic experiment through its connection with the classical orbital precessions induced by the Earth's oblateness $J_2$. \\textcolor{black}{Indeed,} the systematic bias due to the current measurement errors $\\sigma_{\\dot a}$ is of the same order of magnitude of, or even larger than, the expected relativistic signal itself; moreover, it grows linearly with the time span $T$ of the analysis. \\textcolor{black}{Therefore, the parameter-fitting algorit...

  17. 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.

  18. The impact of hydrogen on the formability of AHSS in Nakajima tests

    Science.gov (United States)

    Gao, Qi; Han, Fei; Wortberg, Daniel; Bleck, Wolfgang; Liewald, Mathias

    2016-10-01

    The application of Advanced High Strength Steels (AHSS) in the design of automotive body-in-white structures meets the requirement of light weight construction. The susceptibility to Hydrogen Embrittlement however, limits the wide application of steel grades over 1000 MPa. Up to now, various published studies focused on the hydrogen effects on mechanical properties; the impact of hydrogen on formability was not clarified. The present work aims to evaluate the influence of hydrogen on forming limit and fracture behavior in different strain states during the forming process. The hydrogen concentration in the material was modified by cathodic electro-charging. Nakajima tests in three strain conditions on uncharged and pre-charged samples were carried out. The localized necking was determined on the basis of the representative thinning rate in necking areas. The results revealed the shift of forming limits and critical strains to fracture owing to the presence of massive hydrogen. The fractography by Scanning Electron Microscope gave evidence of typical hydrogen-induced cleavage fracture on pre-charged samples.

  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. Irradiation programme SAMARCANDE. Impact test results; Bestrahlungsprogramm SAMARCANDE. Ergebnisse der Kerbschlagbiegeversuche

    Energy Technology Data Exchange (ETDEWEB)

    Rieth, M.; Dafferner, B.; Ries, H.; Romer, O.

    1994-08-01

    To produce proof of the usability of the martensitic 10.5% Cr-steel 1.4914 as alternative wrapper tube material the irradiation induced embrittlement was characterised with impact tests. The examinations were based on specimens, which were fabricated out of an irradiated wrapper tube. The irradiation was carried out within the EFR project (European Fast Reactor) in the PHENIX reactor in Cadarache (irradiation programme SAMARCANDE). The evaluation of ductile-to-brittle-transition temperatures and upper shelf energies of safety relevant segments of the tube led to a positive assessment: the 10.5% Cr-steel 1.4914 is excellently suited to the usage as wrapper tube material. (orig.) [Deutsch] Zum Nachweis der Tauglichkeit des martensitischen 10,5% Cr-Stahls 1.4914 als alternaties Kastenmaterial wurde anhand von Kerbschlagbiegeversuchen die bestrahlungsinduzierte Versproedung charakterisiert. Die Untersuchungen stuetzten sich hauptsaechlich auf Proben, die aus einem im Rahmen des EFR-Projekts in Cadarache (PHENIX-Reaktor, Bestrahlungsprogramm SAMAR-CANDE) bestrahlten Brennelementhuellkasten gefertig wurden. Die Auswertung der Sproedbruchuebergangstemperatur und der Schlagarbeit in der Hochlage der sicherheitsrelevanten Segmente des Huellkastens fuehrte zu einer positiven Bewertung: der 10,5% Cr-Stahl 1.4914 ist fuer den Einsatz als Brennelementhuellkastenwerkstoff bestens geeignet. (orig.)

  1. 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.

  2. Biological impact assessment of nanomaterial used in nanomedicine. introduction to the NanoTEST project.

    Science.gov (United States)

    Juillerat-Jeanneret, Lucienne; Dusinska, Maria; Fjellsbø, Lise Marie; Collins, Andrew R; Handy, Richard D; Riediker, Michael

    2015-05-01

    Therapeutic nanoparticles (NPs) are used in nanomedicine as drug carriers or imaging agents, providing increased selectivity/specificity for diseased tissues. The first NPs in nanomedicine were developed for increasing the efficacy of known drugs displaying dose-limiting toxicity and poor bioavailability and for enhancing disease detection. Nanotechnologies have gained much interest owing to their huge potential for applications in industry and medicine. It is necessary to ensure and control the biocompatibility of the components of therapeutic NPs to guarantee that intrinsic toxicity does not overtake the benefits. In addition to monitoring their toxicity in vitro, in vivo and in silico, it is also necessary to understand their distribution in the human body, their biodegradation and excretion routes and dispersion in the environment. Therefore, a deep understanding of their interactions with living tissues and of their possible effects in the human (and animal) body is required for the safe use of nanoparticulate formulations. Obtaining this information was the main aim of the NanoTEST project, and the goals of the reports collected together in this special issue are to summarise the observations and results obtained by the participating research teams and to provide methodological tools for evaluating the biological impact of NPs.

  3. Damage evolution in GLARE fibre-metal laminate under repeated low-velocity impact tests

    Science.gov (United States)

    Morinière, Freddy; Alderliesten, René; Tooski, Mehdi; Benedictus, Rinze

    2012-12-01

    An experimental study was performed on the repeated low-velocity impact behaviour of GLARE. Damage evolution in the material constituents was characterised with successive number of impacts. Records were correlated with visual inspection, ultrasound C-scan and chemical etching. The stiffness of the plate varied when cumulating the number of impacts. Damage accumulation was limited thanks to the synthesis of unidirectional composite and metal. The glass/epoxy plies with high elastic tensile strength could withstand several impacts before perforation despite delamination growth in the vicinity of the impacted area. The damage tolerant aluminium layers prevented the penetration of the projectile and avoided the expansion of delamination. This efficient mechanism preserved the structural integrity of GLARE until first aluminium cracking at the non-impacted side. Among the different failure modes, plate deformation absorbed most of the impact energy. The findings will support the development of a generic quasi-static analytical model and numerical methods.

  4. Introduction of a new dynamic fracture toughness evaluation system

    Science.gov (United States)

    Kobayashi, Toshiro; Yamamoto, Isamu; Niinomi, Mitsuo

    1993-05-01

    The instrumented Charpy impact test has been widely used as a simple method for semiempirically evaluating material impact toughness. The authors have developed a new instrumented Charpy impact testing system, which is called computer aided instrumented Charpy impact testing. Using this system, dynamic fracture toughness parameters and various absorbed energies can be obtained from the load-deflection curve of a single precracked specimen for both ductile and brittle materials. The system has been put into practical use in Japan. This paper introduces the details of the toughness evaluation procedures in the system.

  5. Impact properties of electron beam welds of V–4Ti–4Cr alloys NIFS-HEAT-2 and CEA-J57

    Energy Technology Data Exchange (ETDEWEB)

    Tsisar, Valentyn, E-mail: valentyn_tsisar@ipm.lviv.ua [National Institute for Fusion Science (NIFS), 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Physical–Mechanical Institute of National Academy of Sciences of Ukraine (PhMI NASU), 5 Naukova Street, 79601 Lviv (Ukraine); Karlsruhe Institute of Technology (KIT), Institute for Applied Materials – Material Process Technology (IAM-WPT), Hermann-von-Helmholtz-Platz, 1, 76344 Eggenstein-Leopoldshafen (Germany); Nagasaka, Takuya [National Institute for Fusion Science (NIFS), 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Le Flem, Marion [CEA, DEN, DMN, SRMA, F-91191 Gif Sur Yvette (France); Yeliseyeva, Olga [Physical–Mechanical Institute of National Academy of Sciences of Ukraine (PhMI NASU), 5 Naukova Street, 79601 Lviv (Ukraine); Konys, Jürgen [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials – Material Process Technology (IAM-WPT), Hermann-von-Helmholtz-Platz, 1, 76344 Eggenstein-Leopoldshafen (Germany); Muroga, Takeo [National Institute for Fusion Science (NIFS), 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)

    2014-10-15

    Highlights: • Electron beam welding was applied for V–4Ti–4Cr alloys NIFS-HEAT-2 and CEA-J57. • Weld metal showed superior impact properties in comparison with base metal. • Expected shift in DBTT to higher temperatures does not take place. - Abstract: The Charpy impact properties and microstructure of bead-on-plate electron beam welds of V–4Ti–4Cr alloys NIFS-HEAT-2 (NH-2) and CEA-J57 (J57) were investigated. Weld metal of both grades demonstrated increase in hardness (HV{sub 100} ∼ 180) in comparison with base metal (HV{sub 100} ∼ 135) due to decomposition of Ti–C,O,N precipitates followed by the solid-solution hardening of V-matrix with oxygen. Hardness decreases gradually from the weld metal through the heat affected zone toward the base metal indicating partial decomposition of precipitation bands from the side of heat affected zone directly adjoining weld metal. The latter consists of columnar crystallites (grains) possessing with inner dendritic structure and elongated from the center of weld belt in the direction of heat removal. Thickness of weld metal does not exceed 1 mm while heat affected zone is about 3 mm thick. Absorbed energies of weld metal are superior in comparison with base metal for both grades (NH-2 and J57) while the fracture mode is mainly ductile in the temperature range of impact test from 17 to −196 °C.

  6. The Impact of BIB Spiraling-Induced Missing Data Patterns on Goodness-of-Fit Tests in Factor Analysis.

    Science.gov (United States)

    Kaplan, David

    1995-01-01

    This article considers the impact of missing data arising from balanced incomplete block (BIB) spiraled designs on the chi-square goodness-of-fit test in factor analysis. The new approach is shown to outperform the pairwise available case method for continuous variables and to be comparatively better for dichotomous variables. (SLD)

  7. Testing the Impact of Job-Related Variables on a Utility Judgment Training Criterion beyond Background and Affective Reaction Variables

    Science.gov (United States)

    Blau, Gary; Gibson, Greg; Bentley, Melissa; Chapman, Susan

    2012-01-01

    We tested the incremental impact of a job-related set of variables for explaining a utility judgment training effectiveness variable, that is, course completion skill preparedness, beyond background and course-related variables. Our respondents were two different emergency medical service samples, 415 basics and 742 paramedics, from the 2008 US…

  8. The Multiple Sclerosis Impact Profile (MSIP). Development and testing psychometric properties of an ICF-based health measure

    NARCIS (Netherlands)

    Wynia, Klaske; Middel, Berrie; Van Dijk, Jitse P.; De Ruiter, Han; De Keyser, Jacques; Reijneveld, Sijmen A.

    2008-01-01

    Purpose. The aim of this study was to develop and test the structure of the Multiple Sclerosis Impact Profile (MSIP), and to evaluate its reliability and validity within a large group of MS patients. Method. Data were obtained from a postal survey of 377 patients attending the Groningen MS centre of

  9. 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.

  10. 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…

  11. Testing the impact of local alcohol licencing policies on reported crime rates in England

    Science.gov (United States)

    De Vocht, F; Heron, J; Campbell, R; Egan, M; Mooney, J D; Angus, C; Brennan, A; Hickman, M

    2017-01-01

    Background Excessive alcohol use contributes to public nuisance, antisocial behaviour, and domestic, interpersonal and sexual violence. We test whether licencing policies aimed at restricting its spatial and/or temporal availability, including cumulative impact zones, are associated with reductions in alcohol-related crime. Methods Reported crimes at English lower tier local authority (LTLA) level were used to calculate the rates of reported crimes including alcohol-attributable rates of sexual offences and violence against a person, and public order offences. Financial fraud was included as a control crime not directly associated with alcohol abuse. Each area was classified as to its cumulative licensing policy intensity for 2009–2015 and categorised as ‘passive’, low, medium or high. Crime rates adjusted for area deprivation, outlet density, alcohol-related hospital admissions and population size at baseline were analysed using hierarchical (log-rate) growth modelling. Results 284 of 326 LTLAs could be linked and had complete data. From 2009 to 2013 alcohol-related violent and sexual crimes and public order offences rates declined faster in areas with more ‘intense’ policies (about 1.2, 0.10 and 1.7 per 1000 people compared with 0.6, 0.01 and 1.0 per 1000 people in ‘passive’ areas, respectively). Post-2013, the recorded rates increased again. No trends were observed for financial fraud. Conclusions Local areas in England with more intense alcohol licensing policies had a stronger decline in rates of violent crimes, sexual crimes and public order offences in the period up to 2013 of the order of 4–6% greater compared with areas where these policies were not in place, but not thereafter. PMID:27514936

  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. Damage evolution in GLARE fibre-metal laminate under repeated low-velocity impact tests

    NARCIS (Netherlands)

    Morinière, F.D.; Alderliesten, R.C.; Tooski, M.Y.; Benedictus, R.

    2012-01-01

    An experimental study was performed on the repeated low-velocity impact behaviour of GLARE. Damage evolution in the material constituents was characterised with successive number of impacts. Records were correlated with visual inspection, ultrasound C-scan and chemical etching. The stiffness of the

  14. 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

  15. Test methodology for low-speed rear impact human kinematics and dynamics

    NARCIS (Netherlands)

    Philippens, M.M.G.M.; Cappon, H.J.; Yoganandan, N.; Pintar, F.A.

    2000-01-01

    Design of crash dummies and development of numeric models of the human body require data sets which specify the performance of real humans in crash impact conditions. Rear impact conditions have become increasingly important during the last decade. This resulted in a growing number of research proje

  16. Development of a soil test for determining the impact of soil disturbance

    Science.gov (United States)

    United States Federal law requires land-managing agencies like the US Army to identify and take into account the impacts of their undertakings on archaeological resources. Development of a method that uses changes in the stratification of horizon interfaces to identify the onset of adverse impacts t...

  17. Effect of porcelain shape for strain behavior of strengthened porcelain in impact test

    Science.gov (United States)

    Hayashi, Akemi; Kurachi, Kazumasa; Mizuno, Masatoshi; Ota, Toshitaka

    2011-10-01

    Four types of strengthened porcelains were evaluated by an impact examination machine based on ASTM C368-88. The waveform of strain developed on impact was measured by a strain gauge pasted on the inside surface and the outside surface, vertical and horizontal direction of porcelain. In minute scales, procelain deformed into an oval shape as a whole by an impact onto the rim, where the higher tensile strain occurred in the horizontal direction on the inside surface of porcelain. The maximum tensile strain occurred at the impact point. The waveform of strain, that showed two remarkable peaks, was greatly affected by porcelain shape. In addition it was more or less affected by measurement conditions such as impact energy, weight or speed of hammer, weight for holding, and position of backstops.

  18. 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.

  19. Evaluation of ductile-brittle transition temperature before and after neutron irradiation for RPV steels using small punch tests

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min-Chul [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)]. E-mail: mckim@kaeri.re.kr; Oh, Yong Jun [Hanbat National University, Deogmyeong-dong, Yuseong-gu, Daejeon 305-719 (Korea, Republic of); Lee, Bong Sang [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2005-08-01

    Small punch (SP) tests were performed to evaluate the ductile-brittle transition temperature before and after a neutron irradiation of reactor pressure vessel (RPV) steels produced by different manufacturing (refining) processes. The results were compared to the standard transition temperature shifts from the conventional Charpy tests and the Master Curve fracture toughness tests in accordance with the American Society for Testing and Materials (ASTM) standard E1921. Small punch specimens were taken from a 1/4t location of the vessel thickness and machined into a 10 mm x 10 mm x 0.5 mm dimension. The specimens were irradiated in the research reactors at Korea Atomic Energy Research Institute Nuclear Research Institute in the Czech Republic at the different fluence levels of about 290 deg C. Small punch tests were performed in the temperature range of RT to -196 deg C using a 2.4 mm diameter ball. For the materials before and after irradiation, the small punch transition temperatures (T {sub SP}), which are determined at the middle of the upper small punch energies, showed a linear correlation with the Charpy index temperature, T {sub 41J}. T {sub SP} from the irradiated samples was increased with the fluence levels and was well within the deviation range of the unirradiated data. However, the transition temperature shift from the Charpy test ({delta}T {sub 41J}) shows a better correlation with the transition temperature shift ({delta}T {sub SP(E)}) when a specific small punch energy level rather than the middle energy level of the small punch curve is used to determine the transition temperature. T {sub SP} also had a correlation with the reference temperature (T {sub 0}) from the Master Curve method using a pre-cracked Charpy V-notched (PCVN) specimen.

  20. An experimental study of non-destructive testing on glass fibre reinforced polymer composites after high velocity impact event

    Science.gov (United States)

    Razali, N.; Sultan, M. T. H.; Cardona, F.

    2016-10-01

    A non-destructive testing method on Glass Fibre Reinforced Polymer (GFRP) after high velocity impact event using single stage gas gun (SSGG) is presented. Specimens of C- type and E-type fibreglass reinforcement, which were fabricated with 6mm, 8mm, 10mm and 12mm thicknesses and size 100 mm x 100 mm, were subjected to a high velocity impact with three types of bullets: conical, hemispherical and blunt at various gas gun pressure levels from 6 bar to 60 bar. Visual observation techniques using a lab microscope were used to determine the infringed damage by looking at the crack zone. Dye penetrants were used to inspect the area of damage, and to evaluate internal and external damages on the specimens after impact. The results from visual analysis of the impacted test laminates were discussed and presented. It was found that the impact damage started with induced delamination, fibre cracking and then failure, simultaneously with matrix cracking and breakage, and finally followed by the fibres pulled out. C-type experienced more damaged areas compared to E-type of GFRP.

  1. Impact behavior of reduced-activation steels irradiated to 24 dpa

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

    Charpy impact properties of eight reduced-activation Cr-W ferritic steels were determined after irradiation to {approx}21-24 dpa in the Fast Flux Test Facility (FFTF) at 365{degree}C. Chromium concentrations in the eight steels ranged from 2.25 to 12wt% Cr (steels contained {approx}0.1%C). the 2 1/4Cr steels contained variations of tungsten and vanadium, and the steels with 5, 9, and 12% Cr, contained a combination of 2% W and 0.25% V. A 9Cr in FFTF to {approx}6-8 and {approx}15-17 dpa. Irradiation caused an increase in the DBTT and decrease in the USE, but there was little further change in the DBTT from that observed after the 15-17 dpa irradiation, indicating that the shift had essentially saturated with fluence. The results are encouraging because they indicate that the effect of irradiation on toughness can be faorably affected by changing composition and microstructure.

  2. 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.).

  3. Environmental impact evaluation of static tests of solid propellant propellers; Evaluation de l`impact sur l`environnement des essais statiques de propulseurs a propergol solide

    Energy Technology Data Exchange (ETDEWEB)

    Aguesse, T.; Moreau, S. [DGA, Direction des Missiles et de l`Espace, Centre d`Achevement et d`Essais des Propulseurs et Engins, 33 - Saint Medard en Jalles (France)

    1996-12-31

    The CAEPE, the French Centre of Propellers and Engines Completion and Testing is in charge of the static tests of solid propellant fuelled propellers. In order to determine the schedule of firing permissions, predictive means are used to predict the environmental impact of propellers firing. Calculation and simulation codes are used to build maps of acoustic nuisance and acid fallout. These codes, which use in-situ meteorological radio sounding data, were progressively adjusted during testing of engines with different sizes (up to the Ariane 5 P230 auxiliary propeller). In this presentation, the authors focus on a model derived from the G.A. Briggs` model for the ascension of high temperature effluents. The correct simulation of acid rains requires a good description of this phenomenon. Concerning the other aspects of the codes, the main references are given. (J.S.) 15 refs.

  4. Results of crack-arrest tests on two irradiated high-copper welds

    Energy Technology Data Exchange (ETDEWEB)

    Iskander, S.K.; Corwin, W.R.; Nanstead, R.K. (Oak Ridge National Lab., TN (USA))

    1990-12-01

    The objective of this study was to determine the effect of neutron irradiation on the shift and shape of the lower-bound curve to crack-arrest data. Two submerged-arc welds with copper contents of 0.23 and 0.31 wt % were commercially fabricated in 220-mm-thick plate. Crack-arrest specimens fabricated from these welds were irradiated at a nominal temperature of 288{degree}C to an average fluence of 1.9 {times} 10{sup 19} neutrons/cm{sup 2} (>1 MeV). Evaluation of the results shows that the neutron-irradiation-induced crack-arrest toughness temperature shift is about the same as the Charpy V-notch impact temperature shift at the 41-J energy level. The shape of the lower-bound curves (for the range of test temperatures covered) did not seem to have been altered by irradiation compared to those of the ASME K{sub Ia} curve. 9 refs., 21 figs., 10 tabs.

  5. Fracture Mechanics Study on 155 mm M107E1 Projectile Made from Isothermally Transformed HF-1 Steel

    Science.gov (United States)

    1976-02-01

    of MIO7EI Projectiles.. 22 4. Charpy V-Notch Impact Energy of Tsothermally Transformed HF-i Steel (Heat A) as a Function of Testing Temperature . 23...evaluating rough handling. Specific stress and loading rate data were developed through a series of drop tests of instrumented projectiles. Although the...Impact Toughness The impact toughness of Heat A was investigated at test tempera- tures ranging from -65 degrees F to +1150 degrees F using Charpy V- notch

  6. Impact Testing on Reinforced Carbon-Carbon Flat Panels With BX-265 and PDL-1034 External Tank Foam for the Space Shuttle Return to Flight Program

    Science.gov (United States)

    Melis, Matthew E.; Revilock, Duane M.; Pereira, Michael J.; Lyle, Karen H.

    2009-01-01

    Following the tragedy of the Orbiter Columbia (STS-107) on February 1, 2003, a major effort commenced to develop a better understanding of debris impacts and their effect on the space shuttle subsystems. An initiative to develop and validate physics-based computer models to predict damage from such impacts was a fundamental component of this effort. To develop the models it was necessary to physically characterize reinforced carbon-carbon (RCC) along with ice and foam debris materials, which could shed on ascent and impact the orbiter RCC leading edges. The validated models enabled the launch system community to use the impact analysis software LS-DYNA (Livermore Software Technology Corp.) to predict damage by potential and actual impact events on the orbiter leading edge and nose cap thermal protection systems. Validation of the material models was done through a three-level approach: Level 1-fundamental tests to obtain independent static and dynamic constitutive model properties of materials of interest, Level 2-subcomponent impact tests to provide highly controlled impact test data for the correlation and validation of the models, and Level 3-full-scale orbiter leading-edge impact tests to establish the final level of confidence for the analysis methodology. This report discusses the Level 2 test program conducted in the NASA Glenn Research Center (GRC) Ballistic Impact Laboratory with external tank foam impact tests on flat RCC panels, and presents the data observed. The Level 2 testing consisted of 54 impact tests in the NASA GRC Ballistic Impact Laboratory on 6- by 6-in. and 6- by 12-in. flat plates of RCC and evaluated two types of debris projectiles: BX-265 and PDL-1034 external tank foam. These impact tests helped determine the level of damage generated in the RCC flat plates by each projectile and validated the use of the foam and RCC models for use in LS-DYNA.

  7. Plastic deformation of high-purity a-titanium: model development and validation using the Taylor cylinder impact test

    Science.gov (United States)

    Chandola, Nitin; Revil-Baudard, Benoit; Cazacu, Oana

    2016-08-01

    Results of an experimental study on the quasi-static and high-rate plastic deformation due to impact of a high-purity, polycrystalline, a-titanium material are presented. To quantify the plastic anisotropy and tension-compression asymmetry of the material, first monotonic uniaxial compression and tension tests were carried out at room temperature under quasi-static conditions. It was found that the material is transversely isotropic and displays strong strength differential effects. To characterize the material's strain rate sensitivity, Split Hopkinson Pressure Bar tests in tension and compression were also conducted. Taylor impact tests were performed for impact velocity of 196 m/s. Plastic deformation extended to 64% of the length of the deformed specimen, with little radial spreading. To model simultaneously the observed anisotropy, strain-rate sensitivity, and tension-compression asymmetry of the material, a three-dimensional constitutive model was developed. Key in the formulation is a macroscopic yield function [1] that incorporates the specificities of the plastic flow, namely the combined effects of anisotropy and tension-compression asymmetry. Comparison between model predictions and data show the capabilities of the model to describe with accuracy the plastic behavior of the a-Ti material for both quasi-static and dynamic loadings, in particular, a very good agreement was obtained between the simulated and experimental post-test Taylor specimen geometries.

  8. 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

  9. Prediction of impact response of reinforced concrete slabs subjected to impact of aircraft engine missile. Verification by the results of full-scale impact tests using real jet engine

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Takashi; Ohno, Tomonori [National Defence Academy, Yokosuka, Kanagawa (Japan)

    1995-05-01

    It is of importance to investigate and predict the response of reinforced concrete structures to impact loading from the view point of disaster prevention at nuclear power plant facilities, and there is an urgent requirement for establishment of design methods against the impact of aircraft and/or its engine. The authors proposed a numerical approach for assessing local response characteristics by the high-velocity impact of deformable missiles, and the results of numerical analyses were verified by that of full-scale impact tests using real engine body (GE-J79) reported by Muto et.al. The relation between the crash strength of engine body and the limit thickness of perforation was calculated and illustrated in this paper. (author).

  10. Understanding how pre-impact posture can affect injury outcome in side impact sled tests using a new tool for visualization of cadaver kinematics.

    Science.gov (United States)

    Donlon, John Paul; Poulard, David; Lessley, David; Riley, Patrick; Subit, Damien

    2015-02-01

    The effect of posture and subject-specific factors on injury outcome is an active field of research in injury biomechanics, in particular in automotive safety research where post-mortem human subjects (PMHS) are used as surrogates. Current PMHS tests routinely include acquisition of the subjects׳ geometry and kinematics. However, combining these two datasets to better understand the injury mechanism is still a challenge. This study investigated the connection between pre-impact posture and resulting injuries in six previously published side impact sled tests (three with a rigid wall and three with an airbag) by creating three-dimensional kinematic animations (3DKA) of the tests. The 3DKA allow qualitative assessment of parameters related to posture and their possible effect on injury outcome. The orientation of the struck scapula and the lateral leaning of the torso were identified as potentially significant parameters. The ranges of variation in these parameters were quantified and compared to the number of rib fractures for each subject: the data suggested a correlation, but there was insufficient data for a probabilistic analysis. The 3DKA were published with this study and are freely available.

  11. 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 ...

  12. Evaluation of ductile-brittle transition behavior with neutron irradiation in nuclear reactor pressure vessel steels using small punch test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. C.; Lee, B. S. [KAERI, Taejon (Korea, Republic of); Oh, Y. J. [Hanbat National Univ., Taejon (Korea, Republic of)

    2003-10-01

    A Small Punch (SP) test was performed to evaluate the ductile-brittle transition temperature before and after neutron irradiation in Reactor Pressure Vessel (RPV) steels produced by different manufacturing (refining) processes. The results were compared to the standard transition temperature shifts from the Charpy test and Master Curve fracture toughness test in accordance with the ASTM standard E1921. The samples were taken from 1/4t location of the vessel thickness and machined into a 10x10x0.5mm dimension. Irradiation of the samples was carried out in the research reactor at KAERI (HANARO) at about 290 .deg. C of the different fluence levels respectively. SP tests were performed in the temperature range of RT to -196 .deg. C using a 2.4mm diameter ball. For the materials before and after irradiation, SP transition temperatures (T{sub sp}), which are determined at the middle of the upper and lower SP energies, showed a linear correlation with the Charpy index temperature, T{sub 41J}. T{sub sp} from the irradiated samples was increased as the fluence level increased and was well within the deviation range of the unirradiated data. The TSP had a correlation with the reference temperature (T{sub 0}) from the master curve method using a pre-cracked Charpy V-notched (PCVN) specimen.

  13. Psychological Impact of Predictive Genetic Testing in VCP Inclusion Body Myopathy, Paget Disease of Bone and Frontotemporal Dementia.

    Science.gov (United States)

    Surampalli, Abhilasha; Khare, Manaswitha; Kubrussi, Georgette; Wencel, Marie; Tanaja, Jasmin; Donkervoort, Sandra; Osann, Kathryn; Simon, Mariella; Wallace, Douglas; Smith, Charles; M McInerney-Leo, Aideen; Kimonis, Virginia

    2015-10-01

    Inclusion Body Myopathy associated with Paget's disease of bone and Fronto-temporal Dementia, also known as multisystem proteinopathy is an autosomal dominant, late onset neurodegenerative disorder caused by mutations in Valosin containing protein (VCP) gene. This study aimed to assess uptake and decision making for predictive genetic testing and the impact on psychological well-being. Individuals who had participated in the gene discovery study with a 50 % a priori risk of inheriting VCP disease were sent a letter of invitation offering genetic counseling and testing and were also invited to participate in this psychosocial study. A total of 102 individuals received an invitation and 33 individuals participated in genetic counseling and testing (32.3 %) with 29 completing baseline questionnaires. Twenty completed the follow-up post-test Hospital Anxiety and Depression Scale questionnaire including 13 of the 18 who had tested positive. Mean risk perception at baseline was 50.1 %. Reasons for testing included planning for the future, relieving uncertainty, informing children and satisfying curiosity. At baseline, one quarter of the participants had high levels of anxiety. However, scores were normal one year following testing. In this small cohort, one third of individuals at 50 % risk chose pre-symptomatic testing. Although one quarter of those choosing testing had high anxiety at baseline, this was not evident at follow-up.

  14. 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.

  15. 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

  16. Impact of Accumulated Error on Item Response Theory Pre-Equating with Mixed Format Tests

    Science.gov (United States)

    Keller, Lisa A.; Keller, Robert; Cook, Robert J.; Colvin, Kimberly F.

    2016-01-01

    The equating of tests is an essential process in high-stakes, large-scale testing conducted over multiple forms or administrations. By adjusting for differences in difficulty and placing scores from different administrations of a test on a common scale, equating allows scores from these different forms and administrations to be directly compared…

  17. Impacts

    NARCIS (Netherlands)

    Hellmuth, M.; Kabat, P.

    2003-01-01

    Even without the impacts of climate change, water managers face prodigious challenges in meeting sustainable development goals. Growing populations need affordable food, water and energy. Industrial development demands a growing share of water resources and contaminates those same resources with its

  18. Impact and Cost-Effectiveness of Point-Of-Care CD4 Testing on the HIV Epidemic in South Africa.

    Science.gov (United States)

    Heffernan, Alastair; Barber, Ella; Thomas, Ranjeeta; Fraser, Christophe; Pickles, Michael; Cori, Anne

    2016-01-01

    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.

  19. 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.

  20. HHF test with 80x80x1 Be/Cu/SS Mock-ups for verifying the joining technology of the ITER blanket First Wall

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Bae, Young Dug; Kim, Suk Kwon; Hong, Bong Guen; Jeong, Yong Hwan; Park, Jeong Yong; Choi, Byung Kwon; Jung, Hyun Kyu

    2008-11-15

    Through the fabrication of the Cu/SS and Be/Cu joint specimens, fabrication procedure such as material preparation, canning, degassing, HIP (Hot Isostatic Pressing), PHHT (Post HIP heat treatment) was established. The HIP conditions (1050 .deg. C, 100 MPa 2 hr for Cu/SS, 580 .deg. C 100 MPa 2 hr for Be/Cu) were developed through the investigation on joint specimen fabricated with the various HIP conditions; the destructive tests of joint include the microstructure observation of the interface with the examination of the elemental distribution, tension test, bend test, Charpy impact test and fracture toughness test. However, since the joint should be tested under the High Heat Flux (HHF) conditions like the ITER operation for verifying its joint integrity, several HHF tests were performed like the previous HHF test with the Cu/SS, Be/Cu, Be/Cu/SS Mock-ups. In the present study, the HHF test with Be/Cu/SS Mock-ups, which have 80 mm x 80 mm single Be tile and each material depths were kept to be the same as the ITER blanket FW. The Mock-ups fabricated with three kinds of interlayers such as Cr/Ti/Cu, Ti/Cr/Cu, Ti/Cu, which were different from the developed interlayer (Cr/Cu), total 6 Mock-ups were fabricated. Preliminary analysis were performed to decide the test conditions; they were tested with up to 2.5 MW/m2 of heat fluxes and 20 cycles for each Mock-up in a given heat flux. They were tested with JUDITH-1 at FZJ in Germany. During tests, all Mock-ups showed delamination or full detachment of Be tile and it can be concluded that the joints with these interlayers have a bad joining but it can be used as a good data for developing the Be/Cu joint with HIP.

  1. 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.

  2. 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.

  3. 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.

  4. Hypervelocity impact tests on Space Shuttle Orbiter RCC thermal protection material. [Reinforced Carbon-Carbon laminate

    Science.gov (United States)

    Humes, D. H.

    1978-01-01

    It is noted that the Shuttle Orbiter will be more subject to meteoroid impact than previous spacecraft, due to its greater surface area and longer cumulative time in space. The Orbiter structural material, RCC, a reinforced carbon-carbon laminate with a diffused silicon carbide coating, is evaluated in terms of its resistance to hypervelocity impact. It was found that the specimens (disks with a mass of 34 g and a thickness of 5.0 mm) were cratered only on the front surface when the impact energy was 3 J or less. At 3 J, a trace of the black carbon interior was exposed. The specimens were completely penetrated when the energy was 34 J or greater.

  5. 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.

  6. Testing Younger Dryas ET Impact (YDB) Evidence at Hall’s Cave, Texas

    Science.gov (United States)

    Stafford, T. W.; Lundelius, E.; Kennett, J.; Kennett, D. J.; West, A.; Wolbach, W. S.

    2009-12-01

    Hall’s Cave, Kerrville County Texas, 167 km WSW of Austin, provides a unique opportunity for testing the presence of a chronostratigraphic datum (YDB layer) containing rare and exotic proxies, including nanodiamonds, aciniform soot, and magnetic spherules, the origins of which remain controversial, but possibly derive from a cosmic impact ~12,900 CAL BP. The karst-collapse cave in Cretaceous limestone on the Edwards Plateau contains ≥ 3.7 m of stratified clays grading to clayey silts recording continuous deposition from 16 ka RC yr to present. The cave’s small catchment area and mode of deposition were constant, and the stratigraphy is well dated based on 162 AMS 14C dates from individual vertebrate fossils, snails, charcoal, and sediment chemical fractions. The cave sequence contains an abundant small animal vertebrate fossil record, exhibiting biostratigraphic changes, and the timing of the late Pleistocene megafaunal extinction is consistent with that elsewhere in North America. At 151 cm below datum is the extremely sharp, smooth contact separating lower, dusky red (2.5YR3/2) clays below from overlying dark reddish brown (5YR3/3) clays (forming a 20-cm-thick dark layer) and dating to 13,000 CAL BP, at or close to the age of the YDB datum elsewhere. This appears to be the most distinctive lithologic change of the deglacial sequence. Sediments at or within 10 cm of this contact contain the local extinction of 4 species of bats, the local extinction of the prairie dog (Cynomys sp.) and perhaps other burrowing mammals in response to decrease in soil thickness, and the uppermost occurrence of 6 late Pleistocene megafaunal taxa that, although rare in the cave, do not extend younger than 12.9 ka. We collected and analyzed sediments at high resolution above and below the distinct lithologic contact at 151 cm. The red clays from 151 to 153 cm and immediately preceding the lithologic contact contain an abundance of nanodiamonds (5 different allotropes), aciniform

  7. 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....

  8. 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

  9. Impact of a standardized test package on exit examination scores and NCLEX-RN outcomes.

    Science.gov (United States)

    Homard, Catherine M

    2013-03-01

    The purpose of this ex post facto correlational study was to compare exit examination scores and NCLEX-RN(®) pass rates of baccalaureate nursing students who differed in level of participation in a standardized test package. Three cohort groups emerged as a standardized test package was introduced: (a) students who did not participate in a standardized test package; (b) students with two semesters of a standardized test package; and (c) students with four semesters of a standardized test package. Benner's novice-to-expert theory framed the study in the belief that students best acquire knowledge and skills through practice and reflection. Students participating in four semesters of a standardized test package demonstrated higher exit examination scores and NCLEX-RN pass rates compared with students who did not participate in this package. This study's results could inform nurse educators about strategies to facilitate nursing student success on exit examinations and the NCLEX-RN.

  10. Tensile and impact properties of V-4Cr-4Ti alloy heats 832665 and 832864

    Energy Technology Data Exchange (ETDEWEB)

    Bray, T.S. E-mail: tbray@anl.gov; Tsai, H.; Nowicki, L.J.; Billone, M.C.; Smith, D.L.; Johnson, W.R.; Trester, P.W

    2000-12-01

    Two large heats of V-4Cr-4Ti alloy were produced in the US in the past few years. The first, 832665, was a 500 kg heat procured by the US Department of Energy for basic fusion structural materials research. The second, 832864, was a 1300 kg heat procured by General Atomics for the DIII-D radiative divertor upgrade. Both heats were produced by Oremet-Wah Chang (previously Teledyne Wah Chang of Albany). Tensile properties up to 800 deg. C and Charpy V-notch impact properties down to liquid nitrogen temperature were measured for both heats. The product forms tested for both heats were rolled sheets annealed at 1000 deg. C for 1 h in vacuum. Testing results show the behavior of the two heats to be similar and the reduction of strengths with temperature to be insignificant up to at least 750 deg. C. Ductility of both materials is good in the test temperature range. Impact properties for both heats are excellent - no brittle failures at temperatures above -150 deg. C. Compared to the data for previous smaller laboratory heats of 15-50 kg, the results show that scale-up of vanadium alloy ingot production to sizes useful for reactor blanket design can be successfully achieved as long as reasonable process control is implemented (H. Tsai, et al., Fusion Materials Semiannual Progress Report for Period Ending 30th June 1998, DOE/ER-0313/24, p. 3; H. Tsai, et al., Fusion Materials Semiannual Progress Report for Period Ending 31st December 1998, DOE/ER-0313/25, p. 3)

  11. H-60A/L Passenger Airbag Protection: Vertical and Horizontal Impact Tests

    Science.gov (United States)

    2013-04-30

    sled breaks contact with the thrust piston, the sled coasts to a stop or is stopped with a triggered pneumatic brake system. The impact acceleration...consists of a 4 ft by 8 ft sled positioned on a 204 ft long track and is accelerated using a 24 inch diameter pneumatic actuator. The HIA operates on

  12. Out-of-School Time Program Test Score Impact for Black Children of Single-Parents

    Science.gov (United States)

    Nagle, Barry T.

    2013-01-01

    Out-of-School Time programs and their impact on standardized college entrance exam scores for black or African-American children of single parents who have applied for a competitive college scholarship program is the study focus. Study importance is supported by the large percentage of black children raised by single parents, the large percentage…

  13. Modular and scalable load-wall sled buck for pure-lateral and oblique side impact tests.

    Science.gov (United States)

    Yoganandan, Narayan; Humm, John R; Pintar, Frank A

    2012-05-11

    A considerable majority of side impact sled tests using different types of human surrogates has used a load-wall design not specific to subject anthropometry. The use of one load-wall configuration cannot accurately isolate and evaluate regional responses for the same load-wall geometry. As the anatomy and biomechanical responses of the human torso depends on the region, and anthropomorphic test devices continue to advance and accommodate regional differences, it is important to obtain specific data from sled tests. To achieve this goal, the present study designed a scalable modular load-wall consisting of the shoulder, thorax, abdomen, and superior and inferior pelvis, and lower limb plates. The first five plates were connected to a vertical fixture and the limb plate was connected to another fixture. The width, height, and thickness, and the gap between plates were modular. Independent adjustments in the coronal and sagittal planes allowed region-specific positioning depending on surrogate anthropometry, example pelvis width and seated height. Two tri-axial load cells were fixed on the contralateral face of each plate of the load-wall to record impact force-time histories. The load-wall and vertical fixture design can be used to conduct side impact tests with varying vectors, pure-lateral to anterior and posterior oblique, by appropriately orienting the load-wall with respect to the surrogate. The feasibility of the design to extract region-specific biomechanical data was demonstrated by conducting pure-lateral and anterior oblique sled tests using two different surrogates at a velocity of 6.7m/s. Uses of this design are discussed for different applications.

  14. X60钢级HFW焊管焊缝冲击韧性异常原因分析%Cause Analysis on Abnormal Impact Toughness of X60 Steel HFW Pipe Weld

    Institute of Scientific and Technical Information of China (English)

    赵金兰; 雷俊杰; 王高峰; 聂向晖

    2014-01-01

    通过对某X60钢级HFW焊管进行拉伸试验、压扁试验及-20℃低温冲击试验,发现该焊管焊缝的冲击韧性异常低。采用金相显微分析、扫描电镜分析及能谱分析法对焊缝冲击韧性异常的原因进行了分析。结果表明,焊缝源区存在大量的灰斑,是造成焊缝冲击韧性较低的主要原因,母材组织中存在一定的带状组织也会降低焊缝的冲击韧性,另外,如果焊后热处理工艺不当,就不能起到改善焊缝冲击韧性的作用。%The tensile test, flattening test and -20 ℃ low temperature Charpy impact test on one X60 HFW pipe weld were carried out. It found that the impact toughness abnormal low. The cause of the low impact toughness was analyzed by the metallographic analysis, SEM and energy spectrum analysis. The results showed that, the existence of a large number of gray spot in weld source area is the main cause of low impact toughness, and the banded structure of base metal also can reduce the impact toughness of weld. In addition, improper heat treatment after welding will not improve weld impact toughness.

  15. Testing for Bias against Female Test Takers of the Graduate Management Admissions Test and Potential Impact on Admissions to Graduate Programs in Business.

    Science.gov (United States)

    Wright, Robert E.; Bachrach, Daniel G.

    2003-01-01

    Graduate Management Admission Test (GMAT) scores and grade point average in graduate core courses were compared for 190 male and 144 female business administration students. No significant differences in course performance were found, but males had been admitted with significantly higher GMAT scores, suggesting a bias against women. (Contains 27…

  16. Health Behaviors and Standardized Test Scores: The Impact of School Health Climate on Performance

    Science.gov (United States)

    Gunter, Whitney D.; Daly, Kevin

    2013-01-01

    Research has found that many characteristics are related to performance on standardized tests. Many of these are not necessarily "academic" attributes. One area of this research is on the connection between physical health or lifestyles and test performance. The research that exists in this area is often disconnected with each other and…

  17. ACT Test Preparation Course and Its Impact on Students' College- and Career-Readiness

    Science.gov (United States)

    Parrott, Timothy Nolan

    2012-01-01

    This study examined the effectiveness of an ACT intervention course developed for high school juniors at Anderson County High School during the 2011-2012 school year. This study compared the ACT composite test scores of the treatment group to the ACT composite test scores of the control group by using their PLAN scores as a baseline, to determine…

  18. 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.

  19. The Impact of Testing on the Formation of Children's and Adults' False Memories

    NARCIS (Netherlands)

    Brackmann, Nathalie; Otgaar, Henry; Sauerland, Melanie; Howe, Mark L

    2016-01-01

    Witnesses are frequently questioned immediately following a crime. The effects of such testing on false recall are inconclusive: Testing may inoculate against subsequent misinformation or enhance false memory formation. We examined whether different types of processing can account for these discrepa

  20. 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.

  1. 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

    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.......4 +/- 0.6 vs. 6.9 +/- 0.5; n = 20). The YE-players performed better (P Yo-Yo IR2 (1023 +/- SE vs. 893 +/- SE m). The mean heart rate during the PT-test was 173 +/- 4 b.p.m. (90 +/- 2% of HRmax). Blood lactate, glucose, and ammonia reached 5.6 +/- 0.7, 6.2 +/- 0.6 mmol L...

  2. 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.

  3. Impact of gene patents and licensing practices on access to genetic testing for cystic fibrosis.

    Science.gov (United States)

    Chandrasekharan, Subhashini; Heaney, Christopher; James, Tamara; Conover, Chris; Cook-Deegan, Robert

    2010-04-01

    Cystic fibrosis is one of the most commonly tested autosomal recessive disorders in the United States. Clinical cystic fibrosis is associated with mutations in the CFTR gene, of which the most common mutation among Caucasians, DeltaF508, was identified in 1989. The University of Michigan, Johns Hopkins University, and the Hospital for Sick Children, where much of the initial research occurred, hold key patents on cystic fibrosis genetic sequences, mutations, and methods for detecting them. Several patents, including the one that covers detection of the DeltaF508 mutation, are jointly held by the University of Michigan and the Hospital for Sick Children in Toronto, with Michigan administering patent licensing in the United States. The University of Michigan broadly licenses the DeltaF508 patent for genetic testing with >60 providers of genetic testing to date. Genetic testing is now used in newborn screening, diagnosis, and for carrier screening. Interviews with key researchers and intellectual property managers, a survey of laboratories' prices for cystic fibrosis genetic testing, a review of literature on cystic fibrosis tests' cost-effectiveness, and a review of the developing market for cystic fibrosis testing provide no evidence that patents have significantly hindered access to genetic tests for cystic fibrosis or prevented financially cost-effective screening. Current licensing practices for cystic fibrosis genetic testing seem to facilitate both academic research and commercial testing. More than 1000 different CFTR mutations have been identified, and research continues to determine their clinical significance. Patents have been nonexclusively licensed for diagnostic use and have been variably licensed for gene transfer and other therapeutic applications. The Cystic Fibrosis Foundation has been engaged in licensing decisions, making cystic fibrosis a model of collaborative and cooperative patenting and licensing practice.

  4. Testing a health impact assessment tool by assessing community opinion about a public park.

    Science.gov (United States)

    Hengpraprom, Sarunya; Bualert, Surat; Sithisarankul, Pornchai

    2012-01-01

    The purpose of this study was to assess a health impact assessment (HIA) tool to determine the perceived health impact by the public of a public park. The authors conducted a cross-sectional study from March to April, 2011, using this HIA questionnaire to collect data and through focus group discussions. We also assessed community concerns about the park and obtained recommendations of how to mitigate possible negative aspects of the parks. Four aspects were listed as possible benefits of the park: physical, mental, social, and spiritual health. The negative aspects mentioned by participants were that a park could be a potential place of assembly for teenagers, a place for theft and crime and accidents among children. The HIA tool used for this research seemed appropriate. The next challenge is to use this tool to assess a more controversial project.

  5. The effect of ultrasonic impact treatment on surface roughening of commercially pure titanium during tensile test

    Science.gov (United States)

    Kozelskaya, Anna; Panin, Alexey; Kazachenok, Marina; Romanova, Varvara; Pochivalov, Yurii

    2016-11-01

    The effect of ultrasonic impact treatment (UIT) on surface roughening of commercially pure titanium specimens under uniaxial tension was investigated. It was shown that the inhibition of the dislocation glide in the specimens subject to the preliminary UIT led smoothing of their surface profile at the meso-and microscale levels. Macroscopic roughening of the surface of the untreated specimens and specimens subjected to preliminary UIT was the same and was determined by the deformation of the underlying grains.

  6. 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.

  7. Cadmium Depletion Impacts on Hardening Neutron6 Spectrum for Advanced Fuel Testing in ATR

    Energy Technology Data Exchange (ETDEWEB)

    Gray S. Chang

    2011-05-01

    For transmuting long-lived isotopes contained in spent nuclear fuel into shorter-lived fission products effectively is in a fast neutron spectrum reactor. In the absence of a fast spectrum test reactor in the United States of America (USA), initial irradiation testing of candidate fuels can be performed in a thermal test reactor that has been modified to produce a test region with a hardened neutron spectrum. A test region is achieved with a Cadmium (Cd) filter which can harden the neutron spectrum to a spectrum similar (although still somewhat softer) to that of the liquid metal fast breeder reactor (LMFBR). A fuel test loop with a Cd-filter has been installed within the East Flux Trap (EFT) of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). A detailed comparison analyses between the cadmium (Cd) filter hardened neutron spectrum in the ATR and the LMFBR fast neutron spectrum have been performed using MCWO. MCWO is a set of scripting tools that are used to couple the Monte Carlo transport code MCNP with the isotope depletion and buildup code ORIGEN-2.2. The MCWO-calculated results indicate that the Cd-filter can effectively flatten the Rim-Effect and reduce the linear heat rate (LHGR) to meet the advanced fuel testing project requirements at the beginning of irradiation (BOI). However, the filtering characteristics of Cd as a strong absorber quickly depletes over time, and the Cd-filter must be replaced for every two typical operating cycles within the EFT of the ATR. The designed Cd-filter can effectively depress the LHGR in experimental fuels and harden the neutron spectrum enough to adequately flatten the Rim Effect in the test region.

  8. A pulse-shaping technique to investigate the behaviour of brittle materials subjected to plate-impact tests

    Science.gov (United States)

    Forquin, Pascal; Zinszner, Jean-Luc

    2017-01-01

    Owing to their significant hardness and compressive strengths, ceramic materials are widely employed for use with protective systems subjected to high-velocity impact loadings. Therefore, their mechanical behaviour along with damage mechanisms need to be significantly investigated as a function of loading rates. However, the classical plate-impact testing procedures produce shock loadings in the brittle sample material which cause unrealistic levels of loading rates. Additionally, high-pulsed power techniques and/or functionally graded materials used as flyer plates to smooth the loading pulse remain costly, and are generally difficult to implement. In this study, a shockless plate-impact technique based on the use of either a wavy-machined flyer plate or buffer plate that can be produced by chip-forming is proposed. A series of numerical simulations using an explicit transient dynamic finite-element code have been performed to design and validate the experimental testing configuration. The calculations, conducted in two-dimensional (2D) plane-strain or in 2D axisymmetric modes, prove that the `wavy' contact surface will produce a pulse-shaping effect, whereas the buffer plate will produce a homogenizing effect of the stress field along the transverse direction of the sample. In addition, `wavy-shape' geometries of different sizes provide an easy way to change the level of loading rate and rise time in an experimentally tested ceramic specimen. Finally, when a shockless compression loading method is applied to the sample, a Lagrangian analysis of data is made possible by considering an assemblage of ceramic plates of different thicknesses in the target, so the axial stress-strain response of the brittle sample material can be provided. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  9. Impact on parents of receiving individualized feedback of psychological testing conducted with children as part of a research study.

    Science.gov (United States)

    Cox, Kelly; Fernandez, Conrad V; Chambers, Christine T; Bandstra, Nancy F; Parker, Jennifer A

    2011-01-01

    While many researchers accept the principle that participants have a right to receive information learned from their participation in research, there are few studies examining the impact of receiving results on participants. This study was developed to examine the impact on parents of the receipt of individual results of research-based psychological testing of their children. A summary of the child's individual results of standardized measures of language and development was sent by mail with the questionnaire designed to assess the impact of receiving results. Response rate from the mailed questionnaire was 55.6% (n=74/133). Most parents reported the results as helpful and positive. The majority would receive results again. Overall, the sharing of individualized feedback from psychological testing conducted as part of a research study was well accepted by parents. This practice appears ethically permissible with appropriate support options for addressing participant concerns upon receiving the results as well options for clinical follow-up for the child.

  10. A user-friendly, open-source tool to project impact and cost of diagnostic tests for tuberculosis.

    Science.gov (United States)

    Dowdy, David W; Andrews, Jason R; Dodd, Peter J; Gilman, Robert H

    2014-06-04

    Most models of infectious diseases, including tuberculosis (TB), do not provide results customized to local conditions. We created a dynamic transmission model to project TB incidence, TB mortality, multidrug-resistant (MDR) TB prevalence, and incremental costs over 5 years after scale-up of nine alternative diagnostic strategies. A corresponding web-based interface allows users to specify local costs and epidemiology. In settings with little capacity for up-front investment, same-day microscopy had the greatest impact on TB incidence and became cost-saving within 5 years if delivered at $10/test. With greater initial investment, population-level scale-up of Xpert MTB/RIF or microcolony-based culture often averted 10 times more TB cases than narrowly-targeted strategies, at minimal incremental long-term cost. Xpert for smear-positive TB had reasonable impact on MDR-TB incidence, but at substantial price and little impact on overall TB incidence and mortality. This user-friendly modeling framework improves decision-makers' ability to evaluate the local impact of TB diagnostic strategies.

  11. An experiment to test advanced materials impacted by intense proton pulses at CERN HiRadMat facility

    Energy Technology Data Exchange (ETDEWEB)

    Bertarelli, A., E-mail: alessandro.bertarelli@cern.ch [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Berthome, E. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Boccone, V. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Carra, F. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Cerutti, F. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Charitonidis, N. [CERN, Engineering Department, Machines and Experimental Facilities Group (EN-MEF), CH-1211 Geneva 23 (Switzerland); École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Charrondiere, C. [CERN, Engineering Department, Industrial Controls and Engineering Group (EN-ICE), CH-1211 Geneva 23 (Switzerland); Dallocchio, A.; Fernandez Carmona, P.; Francon, P.; Gentini, L.; Guinchard, M.; Mariani, N. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Masi, A. [CERN, Engineering Department, Sources, Targets and Interactions Group (EN-STI), CH-1211 Geneva 23 (Switzerland); Marques dos Santos, S.D.; Moyret, P. [CERN, Engineering Department, Mechanical and Materials Engineering Group (EN-MME), CH-1211 Geneva 23 (Switzerland); Peroni, L. [Politecnico di Torino, Department of Mechanical and Aerospace Engineering (DIMEAS), Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Redaelli, S. [CERN, Beams Department, Accelerators and Beams Physics Group (BE-ABP), CH-1211 Geneva 23 (Switzerland); Scapin, M. [Politecnico di Torino, Department of Mechanical and Aerospace Engineering (DIMEAS), Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2013-08-01

    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 Doppler vibrometer and high-speed camera). The method presented in this paper, combining experimental measurements with numerical simulations, may find applications to assess materials under very high strain rates and temperatures in domains well beyond particle physics (severe accidents in fusion and fission nuclear facilities, space debris impacts, fast and intense loadings on materials and structures etc.)

  12. Impact of Probe Placement Error on MIMO OTA Test Zone Performance

    DEFF Research Database (Denmark)

    Fan, Wei; Nielsen, Jesper Ødum; Carreño, Xavier;

    2012-01-01

    Standardization work for MIMO OTA testing methods is currently ongoing, where a multi-probe anechoic chamber based solution is an important candidate. In this paper, the probes located on an OTA ring are used to synthesize a plane wave field in the center of the OTA ring, and the EM field for each...... probe is obtained using FDTD simulation. This paper investigates the extent to which we can control the field structure inside the test zone where the device under test is located. The focus is on performance deterioration introduced by probe placement error including OTA probe orientation error...... and location mismatch, which are general non-idealities in practical MIMO OTA test systems....

  13. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    A. Rudd and D. Bergey

    2015-08-01

    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 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.

  14. Testing foreign language impact on engineering students' scientific problem-solving performance

    Science.gov (United States)

    Tatzl, Dietmar; Messnarz, Bernd

    2013-12-01

    This article investigates the influence of English as the examination language on the solution of physics and science problems by non-native speakers in tertiary engineering education. For that purpose, a statistically significant total number of 96 students in four year groups from freshman to senior level participated in a testing experiment in the Degree Programme of Aviation at the FH JOANNEUM University of Applied Sciences, Graz, Austria. Half of each test group were given a set of 12 physics problems described in German, the other half received the same set of problems described in English. It was the goal to test linguistic reading comprehension necessary for scientific problem solving instead of physics knowledge as such. The results imply that written undergraduate English-medium engineering tests and examinations may not require additional examination time or language-specific aids for students who have reached university-entrance proficiency in English as a foreign language.

  15. Impact of rapid diagnostic testing for chlamydia and gonorrhea on appropriate antimicrobial utilization in the emergency department.

    Science.gov (United States)

    Rivard, Kaitlyn R; Dumkow, Lisa E; Draper, Heather M; Brandt, Kasey L; Whalen, David W; Egwuatu, Nnaemeka E

    2017-02-01

    Prolonged turnaround time of Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) test results may delay time to notification and treatment of test-positive patients and result in unnecessary antimicrobial use in test-negative patients. This quasi-experimental study evaluated the impact of NG/CT rapid diagnostic testing (RDT) in an urban emergency department (ED) on treatment appropriateness, time to notification, and cost. Patients tested in December 2013-January 2014 (traditional group, n=200) were compared with those in December 2014-January 2015 (RDT group, n=200). There was a significant increase in treatment appropriateness in the RDT group, 72.5% versus 60% (P=0.008) and time to results notification was significantly faster (median 17.4 versus 51.5hours, P=0.010). Availability of test result prior to discharge was associated with increased treatment appropriateness (odds ratio, 22.65 [95% confidence interval, 2.86-179.68]). The RDT would save approximately $37,000 annually. These results support the use of NG/CT RDT to expand antimicrobial stewardship efforts within the ED.

  16. Department of Physics' Involvement of the Impact Testing Project of the High Speed Civil Transport Program (HSCT)

    Science.gov (United States)

    VonMeerwall, Ernst D.

    1994-01-01

    The project involved the impact testing of a kevlar-like woven polymer material, PBO. The purpose was to determine whether this material showed any promise as a lightweight replacement material for jet engine fan containment. The currently used metal fan containment designs carry a high drag penalty due to their weight. Projectiles were fired at samples of PBO by means of a 0.5 inch diameter Helium powered gun. The Initial plan was to encase the samples inside a purpose-built steel "hot box" for heating and ricochet containment. The research associate's responsibility was to develop the data acquisition programs and techniques necessary to determine accurately the impacting projectile's velocity. Beyond this, the Research Associate's duties include any physical computations, experimental design, and data analysis necessary.

  17. Ductile growth of crack like flawing during hydrotest; Propagacao dutil de defeitos planares durante teste hidrostatico

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Jose C.; Donato, Guilherme V. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES); Silva, Marcinei S. da; Bastian, Fernando L. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Lima, Romulo S. de [PETROBRAS/AB-RE, Rio de Janeiro, RJ (Brazil)

    2003-07-01

    In this paper effects of hydrostatic testing on ductile propagation of crack like flaw defects were evaluated in API X-60 steel. The model used was based on the J-tearing theory, supported by elastic - plastic fracture mechanics. The J-initiation resistance values (JIc) were determined by fracture mechanic tests using potential drop technique and compact test specimen. The JIc values were also determined from flow stress and Charpy V-notch at plateau, which are both usually available in mill-test data. Despite of being based on small database it seems it could be extended and it will be useful for future analysis. (author)

  18. Test of developing long-term forecasts of world energy impact on the earth's atmosphere

    Science.gov (United States)

    Klimenko, V. V.; Klimenko, A. V.; Tereshin, A. G.

    2015-03-01

    It has been established that the historical approach to world energy forecasting can yield useful results at time horizons with a depth of several decades. The genetic forecast supposes reaching a plateau of global energy consumption at the level of 30 billion tons of coal equivalent and an increase in the carbon dioxide concentration almost to 500 parts per million by the end of the century against the background of a continuing decrease in sulfur dioxide emission. From the historical point of view, the implementation of the most aggressive scenarios of human impact on the atmosphere and climate seems very unlikely.

  19. Potential Impact of Rapid Blood Culture Testing for Gram-Positive Bacteremia in Japan with the Verigene Gram-Positive Blood Culture Test

    Science.gov (United States)

    Matsuda, Mari; Iguchi, Shigekazu; Mizutani, Tomonori; Hiramatsu, Keiichi; Tega-Ishii, Michiru; Sansaka, Kaori; Negishi, Kenta; Shimada, Kimie; Umemura, Jun; Notake, Shigeyuki; Yanagisawa, Hideji; Yabusaki, Reiko; Araoka, Hideki; Yoneyama, Akiko

    2017-01-01

    Background. Early detection of Gram-positive bacteremia and timely appropriate antimicrobial therapy are required for decreasing patient mortality. The purpose of our study was to evaluate the performance of the Verigene Gram-positive blood culture assay (BC-GP) in two special healthcare settings and determine the potential impact of rapid blood culture testing for Gram-positive bacteremia within the Japanese healthcare delivery system. Furthermore, the study included simulated blood cultures, which included a library of well-characterized methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) isolates reflecting different geographical regions in Japan. Methods. A total 347 BC-GP assays were performed on clinical and simulated blood cultures. BC-GP results were compared to results obtained by reference methods for genus/species identification and detection of resistance genes using molecular and MALDI-TOF MS methodologies. Results. For identification and detection of resistance genes at two clinical sites and simulated blood cultures, overall concordance of BC-GP with reference methods was 327/347 (94%). The time for identification and antimicrobial resistance detection by BC-GP was significantly shorter compared to routine testing especially at the cardiology hospital, which does not offer clinical microbiology services on weekends and holidays. Conclusion. BC-GP generated accurate identification and detection of resistance markers compared with routine laboratory methods for Gram-positive organisms in specialized clinical settings providing more rapid results than current routine testing.

  20. Environmental Assessment and Finding of No Significant Impact: The Nevada Test Site Development Corporations's Desert Rock Sky Park at the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    2000-03-01

    The United States Department of Energy has prepared an Environmental Assessment (DOE/EA-1300) (EA) which analyzes the potential environmental effects of developing operating and maintaining a commercial/industrial park in Area 22 of the Nevada Test Site, between Mercury Camp and U.S. Highway 95 and east of Desert Rock Airport. The EA evaluates the potential impacts of infrastructure improvements necessary to support fill build out of the 512-acre Desert Rock Sky Park. Two alternative actions were evaluated: (1) Develop, operate and maintain a commercial/industrial park in Area 22 of the Nevada Test Site, and (2) taking no action. The purpose and need for the commercial industrial park are addressed in Section 1.0 of the EA. A detailed description of the proposed action and alternatives is in section 2.0. Section 3.0 describes the affected environment. Section 4.0 the environmental consequences of the proposed action and alternative. Cumulative effects are addressed in Section 5.0. Mitigation measures are addressed in Section 6.0. The Department of Energy determined that the proposed action of developing, operating and maintaining a commercial/industrial park in Area 22 of the Nevada Test Site would best meet the needs of the agency.

  1. Potential Impact of Rapid Blood Culture Testing for Gram-Positive Bacteremia in Japan with the Verigene Gram-Positive Blood Culture Test

    Directory of Open Access Journals (Sweden)

    Ken Kikuchi

    2017-01-01

    Full Text Available Background. Early detection of Gram-positive bacteremia and timely appropriate antimicrobial therapy are required for decreasing patient mortality. The purpose of our study was to evaluate the performance of the Verigene Gram-positive blood culture assay (BC-GP in two special healthcare settings and determine the potential impact of rapid blood culture testing for Gram-positive bacteremia within the Japanese healthcare delivery system. Furthermore, the study included simulated blood cultures, which included a library of well-characterized methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant enterococci (VRE isolates reflecting different geographical regions in Japan. Methods. A total 347 BC-GP assays were performed on clinical and simulated blood cultures. BC-GP results were compared to results obtained by reference methods for genus/species identification and detection of resistance genes using molecular and MALDI-TOF MS methodologies. Results. For identification and detection of resistance genes at two clinical sites and simulated blood cultures, overall concordance of BC-GP with reference methods was 327/347 (94%. The time for identification and antimicrobial resistance detection by BC-GP was significantly shorter compared to routine testing especially at the cardiology hospital, which does not offer clinical microbiology services on weekends and holidays. Conclusion. BC-GP generated accurate identification and detection of resistance markers compared with routine laboratory methods for Gram-positive organisms in specialized clinical settings providing more rapid results than current routine testing.

  2. Building America Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts, Tyler, Texas

    Energy Technology Data Exchange (ETDEWEB)

    2015-08-01

    ?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 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. 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.

  3. Emerging Rapid Resistance Testing Methods for Clinical Microbiology Laboratories and Their Potential Impact on Patient Management

    Directory of Open Access Journals (Sweden)

    Hagen Frickmann

    2014-01-01

    Full Text Available Atypical and multidrug resistance, especially ESBL and carbapenemase expressing Enterobacteriaceae, is globally spreading. Therefore, it becomes increasingly difficult to achieve therapeutic success by calculated antibiotic therapy. Consequently, rapid antibiotic resistance testing is essential. Various molecular and mass spectrometry-based approaches have been introduced in diagnostic microbiology to speed up the providing of reliable resistance data. PCR- and sequencing-based approaches are the most expensive but the most frequently applied modes of testing, suitable for the detection of resistance genes even from primary material. Next generation sequencing, based either on assessment of allelic single nucleotide polymorphisms or on the detection of nonubiquitous resistance mechanisms might allow for sequence-based bacterial resistance testing comparable to viral resistance testing on the long term. Fluorescence in situ hybridization (FISH, based on specific binding of fluorescence-labeled oligonucleotide probes, provides a less expensive molecular bridging technique. It is particularly useful for detection of resistance mechanisms based on mutations in ribosomal RNA. Approaches based on MALDI-TOF-MS, alone or in combination with molecular techniques, like PCR/electrospray ionization MS or minisequencing provide the fastest resistance results from pure colonies or even primary samples with a growing number of protocols. This review details the various approaches of rapid resistance testing, their pros and cons, and their potential use for the diagnostic laboratory.

  4. Genetic testing likelihood: the impact of abortion views and quality of life information on women's decisions.

    Science.gov (United States)

    Wilson, Jessica L; Ferguson, Gail M; Thorn, Judith M

    2011-04-01

    Little is known about factors predicting the likelihood of choosing genetic testing in college aged women versus older women, including knowledge of quality of life (QOL) associated with a disorder. Using vignettes with female college students (Experiment 1: n=257, mean age=19.70 yrs) and female faculty/staff/alumni (Experiment 2: n (nulliparous)=83, mean age=30.20 yrs; n (mothers)=53, mean age=33.77 yrs), we examined the contribution of multiple factors to predicting genetic testing likelihood for cystic fibrosis. We investigated malleable situational factors (style of genetic risk presentation and providing QOL information including physical and social aspects) and stable dispositional factors (abortion views). Parity (i.e., prior births) was more influential in women's genetic testing likelihood than was age. Greater acceptability of abortion for oneself and self-assessed knowledge following QOL information were predictors of higher testing likelihood for college students. Greater acceptability of abortion for another person was a predictor for nulliparous women. Abortion views moderated the effect of predictors for nulliparous women and mothers. Findings encourage genetic counselors to utilize QOL information to promote informed decision making through genetic testing.

  5. The impact of financing of screening tests on utilization and outcomes: The case of amniocentesis.

    Science.gov (United States)

    Shurtz, Ity; Brzezinski, Amnon; Frumkin, Ayala

    2016-07-01

    We use a 1993 policy change in Israel's public healthcare system that lowered the eligibility age for amniocentesis to 35 to study the effects of financing of screening tests. Financing is found to have increased amniocentesis testing by about 35%. At ages above the eligibility threshold, utilization rates rose to roughly 33%, reflection nearly full takeup among prospective users of amniocentesis. Additionally, whereas below the age-35 threshold amniocentesis utilization rates increase with maternal age, this relation is muted above this age. Finally, no evidence is found that financing affects outcomes such as pregnancy terminations and births of children with Down syndrome. These results support the view that women above the eligibility threshold tend to refrain from acquiring inexpensive information about their degree of risk that absent the financing they would acquire, and instead, undergo the accurate and costly test regardless of additional information that noninvasive screening would provide.

  6. Diagnosis of food allergies: the impact of oral food challenge testing.

    Science.gov (United States)

    Ito, Komei

    2013-01-01

    A diagnosis of food allergies should be made based on the observation of allergic symptoms following the intake of suspected foods and the presence of allergen-specific IgE antibodies. The oral food challenge (OFC) test is the most reliable clinical procedure for diagnosing food allergies. Specific IgE testing of allergen components as well as classical crude allergen extracts helps to make a more specific diagnosis of food allergies. The Japanese Society of Pediatric Allergy and Clinical Immunology issued the 'Japanese Pediatric Guideline for Food Allergy 2012' to provide information regarding the standardized diagnosis and management of food allergies. This review summarizes recent progress in the diagnosis of food allergies, focusing on the use of specific IgE tests and the OFC procedure in accordance with the Japanese guidelines.

  7. Analysis of the 2007 Chinese ASAT Test and the Impact of its Debris on the Space Environment

    Science.gov (United States)

    Kelso, T.

    On 2007 January 11, the People's Republic of China conducted a successful direct-ascent ASAT test against one of their own defunct polar-orbiting weather satellites. The test produced at least 1,337 pieces of debris large enough to be routinely tracked by the US Space Surveillance Network and the NASA Orbital Debris Program Office estimated it generated over 35,000 pieces of debris down to 1 centimeter in size. While this event captured worldwide attention in the weeks and months after the test was revealed, much of the information provided in the press was inaccurate or misleading and did not appear to be based on scientific analysis of the data available to the public. In order to help the public and key policy makers more fully understand the nature of the event and its impact on the existing satellite population, the Center for Space Standards & Innovation developed a series of animations, images, and graphical analyses to more clearly portray this event and provide a factual foundation for the subsequent debate. Those materials were all made publicly available via the Internet without restriction and have appeared in numerous publications. This paper will summarize the primary areas of analysis of this event, to include a confirmation of the basic facts initially reported in Aviation Week & Space Technology, a visualization of the initial spread of the debris cloud in the first couple of hours after the attack, analysis of the impact of the debris on the LEO space environment including the number of satellites potentially affected and the increase in the number of conjunctions, a look at the current debris environment, and an assessment of the orbital lifetimes that shows that these impacts will last not for years but for centuries. The visualization techniques used to portray these analyses played a substantial role in helping the scientific community to quickly and easily convey important aspects of this event to policy makers and the public at large.

  8. Non-destructive testing of concrete structures with the impact-echo method; Zerstoerungsfreie Pruefung von Betonbauteilen mit dem Impact-Echo-Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Algernon, Daniel; Feistkorn, Sascha; Scherrer, Michael [SVTI Schweizerischer Verein fuer technische Inspektionen, Wallisellen (Switzerland). Nuklearinspektorat

    2016-05-01

    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. [German] Das Impact-Echo-Verfahren beruht auf der Nutzung elastischer Wellen. Es wurde in den 1980er Jahren fuer die Pruefung von Stahlbetonbauteilen entwickelt und ist derzeit weit verbreitet. Haupteinsatzgebiete sind die Bauteil- und Schichtdickenmessung sowie die Detektion von Delaminationen, Hohl- und anderen Fehlstellen. Insbesondere wird das Verfahren auch zur Pruefung des Verpresszustandes von Spannkanaelen herangezogen. Eine weitere Anwendung ist die Bestimmung mechanischer Materialparameter wie dem Elastizitaetsmodul. Seit der urspruenglichen Entwicklung hat das Verfahren verschiedene Weiterentwicklungen erfahren. Die Ueberfuehrung von einem Einzelpunktmessverfahren hin zu einer flaechigen Bauteilpruefung hat die Einsatzmoeglichkeiten durch die optimierte Messdatenaufnahme und -auswertung vergroessert und eine wichtige Voraussetzung zur Erhoehung der Leistungsfaehigkeit geliefert. Der Einsatz

  9. Impact of point-of-care CD4 testing on linkage to HIV care: a systematic review

    Directory of Open Access Journals (Sweden)

    Elke Wynberg

    2014-01-01

    Full Text Available Introduction: Point-of-care testing for CD4 cell count is considered a promising way of reducing the time to eligibility assessment for antiretroviral therapy (ART and of increasing retention in care prior to treatment initiation. In this review, we assess the available evidence on the patient and programme impact of point-of-care CD4 testing. Methods: We searched nine databases and two conference sites (up until 26 October 2013 for studies reporting patient and programme outcomes following the introduction of point-of-care CD4 testing. Where appropriate, results were pooled using random-effects methods. Results: Fifteen studies, mainly from sub-Saharan Africa, were included for review, providing evidence for adults, adolescents, children and pregnant women. Compared to conventional laboratory-based testing, point-of-care CD4 testing increased the likelihood of having CD4 measured [odds ratio (OR 4.1, 95% CI 3.5–4.9, n=2] and receiving a CD4 result (OR 2.8, 95% CI 1.5–5.6, n=6. Time to being tested was significantly reduced, by a median of nine days; time from CD4 testing to receiving the result was reduced by as much as 17 days. Evidence for increased treatment initiation was mixed. Discussion: The results of this review suggest that point-of-care CD4 testing can increase retention in care prior to starting treatment and can also reduce time to eligibility assessment, which may result in more eligible patients being initiated on ART.

  10. Impact of vocational interests, previous academic experience, gender and age on Situational Judgement Test performance

    NARCIS (Netherlands)

    Schripsema, Nienke R; van Trigt, Anke M; Borleffs, Jan C C; Cohen-Schotanus, Janke

    2017-01-01

    Situational Judgement Tests (SJTs) are increasingly implemented in medical school admissions. In this paper, we investigate the effects of vocational interests, previous academic experience, gender and age on SJT performance. The SJT was part of the selection process for the Bachelor's degree progra

  11. The Impact of Digital Skills on Educational Outcomes: Evidence from Performance Tests

    Science.gov (United States)

    Pagani, Laura; Argentin, Gianluca; Gui, Marco; Stanca, Luca

    2016-01-01

    Digital skills are increasingly important for labour market outcomes and social participation. Do they also matter for academic performance? This paper investigates the effects of digital literacy on educational outcomes by merging data from the Italian National Assessment in secondary schools with an original data-set on performance tests of…

  12. Integrating GIS in the Middle School Curriculum: Impacts on Diverse Students' Standardized Test Scores

    Science.gov (United States)

    Goldstein, Donna; Alibrandi, Marsha

    2013-01-01

    This case study conducted with 1,425 middle school students in Palm Beach County, Florida, included a treatment group receiving GIS instruction (256) and a control group without GIS instruction (1,169). Quantitative analyses on standardized test scores indicated that inclusion of GIS in middle school curriculum had a significant effect on student…

  13. The Impact of Mobile Learning on Student Performance as Gauged by Standardised Test (NAPLAN) Scores

    Science.gov (United States)

    Males, Steven; Bate, Frank; Macnish, Jean

    2017-01-01

    This paper discusses the National Assessment Program for Literacy and Numeracy (NAPLAN) performance of Years Five, Seven and Nine students in standardised tests prior and post the implementation of a mobile learning initiative in a Western Australian school for boys. The school sees the use of ICT as important in enhancing its potential to deliver…

  14. The impact of discussing exercise test results of young asthmatic children on adherence to maintenance medication

    NARCIS (Netherlands)

    Visser, R.; Brusse-Keizer, M.; Palen, van der J.; Klok, T.; Thio, B.J.

    2015-01-01

    Objective: Parents’ awareness of their child’s asthma may improve by discussing an exercise challenge test (ECT) result with them. We investigated the influence of discussing an ECT result with parents on adherence to inhaled maintenance medication, parental illness perceptions and medication belief

  15. Ethical Issues in Sociometric Testing: Impact of Sociometric Measures on Interaction Behavior.

    Science.gov (United States)

    Hayvren, Maureen; Hymel, Shelley

    1984-01-01

    Examines the immediate and long term effects of sociometric testing on preschool children's peer interactions. Positive and negative nomination as well as rating-scale sociometric measures were administered individually to children from two preschool classrooms, and behavioral observations of peer interactions were conducted before, after, and…

  16. A study of the impact of adding HPV types to cervical cancer screening and triage tests.

    Science.gov (United States)

    Schiffman, Mark; Khan, Michelle J; Solomon, Diane; Herrero, Rolando; Wacholder, Sholom; Hildesheim, Allan; Rodriguez, Ana Cecilia; Bratti, Maria C; Wheeler, Cosette M; Burk, Robert D

    2005-01-19

    Use of human papillomavirus (HPV) testing in cervical cancer prevention is increasing rapidly. A DNA test for 13 HPV types that can cause cervical cancer is approved in the United States for co-screening with cytology of women >or=30 years old and for triage of women of all ages with equivocal cytology. However, most infections with HPV are benign. We evaluated trade-offs between specificity and sensitivity for approximately 40 HPV types in predicting cervical intraepithelial neoplasia 3 and cancer in two prospective studies: a population-based screening study that followed 6196 women aged 30-94 years from Costa Rica for 7 years and a triage study that followed 3363 women aged 18-90 years with equivocal cytology in four U.S. centers for 2 years. For both screening and triage, testing for more than about 10 HPV types decreased specificity more than it increased sensitivity. The minimal increases in sensitivity and in negative predictive value achieved by adding HPV types to DNA tests must be weighed against the projected burden to thousands of women falsely labeled as being at high risk of cervical cancer.

  17. Testing Foreign Language Impact on Engineering Students' Scientific Problem-Solving Performance

    Science.gov (United States)

    Tatzl, Dietmar; Messnarz, Bernd

    2013-01-01

    This article investigates the influence of English as the examination language on the solution of physics and science problems by non-native speakers in tertiary engineering education. For that purpose, a statistically significant total number of 96 students in four year groups from freshman to senior level participated in a testing experiment in…

  18. The Impact of Personality on Training-Related Aspects of Motivation: Test of a Longitudinal Model

    Science.gov (United States)

    Rowold, Jens

    2007-01-01

    A model that proposed dispositional influences on training-related aspects of motivation was developed. More specifically, the model predicted influences of the Big Five personality variables on motivation to learn and transfer motivation, while controlling for general attitudes toward training. The model was tested empirically, drawing on a…

  19. Emotional Intelligence Tests: Potential Impacts on the Hiring Process for Accounting Students

    Science.gov (United States)

    Nicholls, Shane; Wegener, Matt; Bay, Darlene; Cook, Gail Lynn

    2012-01-01

    Emotional intelligence is increasingly recognized as being important for professional career success. Skills related to emotional intelligence (e.g. organizational commitment, public speaking, teamwork, and leadership) are considered essential. Human resource professionals have begun including tests of emotional intelligence (EI) in job applicant…

  20. Testing Causal Impacts of a School-Based SEL Intervention Using Instrumental Variable Techniques

    Science.gov (United States)

    Torrente, Catalina; Nathanson, Lori; Rivers, Susan; Brackett, Marc

    2015-01-01

    Children's social-emotional skills, such as conflict resolution and emotion regulation, have been linked to a number of highly regarded academic and social outcomes. The current study presents preliminary results from a causal test of the theory of change of RULER, a universal school-based approach to social and emotional learning (SEL).…