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Sample records for combined punching shear

  1. Recent progress in shear punch testing

    SciTech Connect

    Hamilton, M.L.; Toloczko, M.B.; Lucas, G.E.

    1994-09-01

    The shear punch test was developed in response to the needs of the materials development community for small-scale mechanical properties tests. Such tests will be of great importance when a fusion neutron simulation device is built, since such a device is expected to have a limited irradiation volume. The shear punch test blanks a circular disk from a fixed sheet metal specimen, specifically a TEM disk. Load-displacement data generated during the test can be related to uniaxial tensile properties such as yield and ultimate strength. Shear punch and tensile tests were performed at room temperature on a number of unirradiated aluminum, copper, vanadium, and stainless steel alloys and on several irradiated aluminum alloys. Recent results discussed here suggest that the relationship between shear punch strength and tensile strength varies with alloy class, although the relationship determined for the unirradiated condition remains valid for the irradiated aluminum alloys.

  2. Strength of Footing with Punching Shear Preventers

    PubMed Central

    Lee, Sang-Sup; Moon, Jiho; Park, Keum-Sung; Bae, Kyu-Woong

    2014-01-01

    The punching shear failure often governs the strength of the footing-to-column connection. The punching shear failure is an undesirable failure mode, since it results in a brittle failure of the footing. In this study, a new method to increase the strength and ductility of the footing was proposed by inserting the punching shear preventers (PSPs) into the footing. The validation and effectiveness of PSP were verified through a series of experimental studies. The nonlinear finite element analysis was then performed to demonstrate the failure mechanism of the footing with PSPs in depth and to investigate the key parameters that affect the behavior of the footing with PSPs. Finally, the design recommendations for the footing with PSPs were suggested. PMID:25401141

  3. 3. INTERIOR VIEW LOOKING SOUTH SHOWING PUNCH AND SHEAR MACHINE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. INTERIOR VIEW LOOKING SOUTH SHOWING PUNCH AND SHEAR MACHINE (manufactured by Cleveland Punch and Shear Works Company, USA) - Cambria & Indiana Railroad, Blacksmith Shop, .25 miles northwest of Colver, Colver, Cambria County, PA

  4. 23. NORTHEAST TO CIRCA 1875 POWER SHEAR, PUNCH, AND RIVETING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. NORTHEAST TO CIRCA 1875 POWER SHEAR, PUNCH, AND RIVETING MACHINE SET UP TO DEMONSTRATE USE IN RIVETING COMPONENTS OF WHEEL ARMS FOR ELI WINDMILLS. HISTORIC DEBRIS FROM PUNCHING WORK IS VISIBLE BENEATH THE MACHINE IN THE OPERATOR'S PIT.' ON THE LEFT IS A U-SHAPED LOVEJOY FIELD PUNCH FOR USE IN INSTALLING STEEL WINDMILL/TOWER COMPONENTS. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  5. 16. BUFFALO IRONWORKER (PUNCH AND SHEAR ON RIGHT), IN COVERED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. BUFFALO IRONWORKER (PUNCH AND SHEAR ON RIGHT), IN COVERED AREA BETWEEN WAREHOUSES A AND B, LOOKING SOUTH - Hillman Barge & Construction Company, Paul Thomas Boulevard, Brownsville, Fayette County, PA

  6. 17. GEAR BOXES, BUFFALO IRONWORKER (PUNCH AND SHEAR ON LEFT), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. GEAR BOXES, BUFFALO IRONWORKER (PUNCH AND SHEAR ON LEFT), IN COVERED AREA BETWEEN WAREHOUSES A AND B, LOOKING EAST - Hillman Barge & Construction Company, Paul Thomas Boulevard, Brownsville, Fayette County, PA

  7. The Effect of Test Machine Compliance on the Measured Shear Punch Yield Stress as Predicted Using Finite Element Analysis

    SciTech Connect

    Toloczko, Mychailo; Abe, Katsunori; Hamilton, Margaret L.; Garner, Francis A.; Kurtz, Richard J.

    2001-10-01

    In previous research involving the use of the shear punch test, it was assumed that the displacement of the punch tip was only slightly different than the crosshead displacement. The present work explores this assumption and its ramifications by simulating the shear punch test with finite element analysis (FEA). The simulations suggest that punch tip displacement is much less than previously assumed, and that for the test frames which have been used, crosshead displacement is over an order of magnitude greater than punch tip displacement. This difference in displacements is thought to be due to test machine and punch compliance, and a simple elasticity calculation of the compliance of the punch, the test machine, and a specimen gives a result which is in agreement with the FEA simulations. The effect of using punch tip displacement on the observed effective shear yield stress was evaluated using FEA simulated shear punch tests on several different metals. Yield was measured at several different offset shear strains with a 1.0% offset shear yield strength measurement providing the best correlation with 0.2% offset uniaxial yield strength. When using the 1.0% offset shear yield values, the previously observed material-to-material variability in the tensile-shear correlation all but disappeared. Based on this work, it appears that the material-to-material variations in prior correlations between uniaxial yield strength and shear yield strength is due to a combination of large test machine compliance and material-to-material differences in the work hardening exponent.

  8. 29 CFR 570.59 - Occupations involved in the operation of power-driven metal forming, punching, and shearing...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... forming, punching, and shearing machines (Order 8). 570.59 Section 570.59 Labor Regulations Relating to... in the operation of power-driven metal forming, punching, and shearing machines (Order 8). (a... following power-driven metal forming, punching, and shearing machines: (i) All rolling machines, such...

  9. Tensile-shear correlations obtained from shear punch test technique using a modified experimental approach

    NASA Astrophysics Data System (ADS)

    Karthik, V.; Visweswaran, P.; Vijayraghavan, A.; Kasiviswanathan, K. V.; Raj, Baldev

    2009-09-01

    Shear punch testing has been a very useful technique for evaluating mechanical properties of irradiated alloys using a very small volume of material. The load-displacement data is influenced by the compliance of the fixture components. This paper describes a modified experimental approach where the compliances of the punch and die components are eliminated. The analysis of the load-displacement data using the modified setup for various alloys like low carbon steel, SS316, modified 9Cr-1Mo, 2.25Cr-1Mo indicate that the shear yield strength evaluated at 0.2% offset of normalized displacement relates to the tensile YS as per the Von Mises yield relation ( σys = 1.73 τys). A universal correlation of type UTS = mτmax where m is a function of strain hardening exponent, is seen to be obeyed for all the materials in this study. The use of analytical models developed for blanking process are explored for evaluating strain hardening exponent from the load-displacement data. This study is directed towards rationalizing the tensile-shear empirical correlations for a more reliable prediction of tensile properties from shear punch tests.

  10. Correlation between shear punch and tensile data for neutron-irradiated aluminum alloys

    SciTech Connect

    Hamilton, M.L.; Edwards, D.J.; Toloczko, M.B.

    1995-04-01

    This work was performed to determine whether shear punch and tensile data obtained on neutron irradiated aluminum alloys exhibited the same type of relationship as had been seen in other work and to assess the validity of extrapolating the results to proton-irradiated alloys. This work was also meant to be the first of a series of similar test matrices designed to determine whether the shear punch/tensile relationship varied or was the same for different alloy classes.

  11. Shear Punch Tests Performed Using a New Low Compliance Test Fixture

    SciTech Connect

    Toloczko, Mychailo B.; Kurtz, Richard J.; Hasegawa, Akira; Abe, K

    2002-12-01

    Based on a recent finite element analysis (FEA) study performed on the shear punch test technique, it was suggested that compliance in a test frame and fixturing which is quite acceptable for uniaxial tensile tests, is much too large for shear punch tests. The FEA study suggested that this relatively large compliance was masking both the true yield point and the shape of the load versus displacement trace obtained in shear punch tests. The knowledge gained from the FEA study was used to design a new shear punch test fixture which more directly measures punch tip displacement. The design of this fixture, the traces obtained from this fixture, and the correlation between uniaxial yield stress and shear yield stress obtained using this fixture, are presented here. In general, traces obtained from the new fixture contain much less compliance resulting in a trace shape which is more similar in appearance to a corresponding uniaxial tensile trace. Due to the more direct measurement of displacement, it was possible to measure yield stress at an offset shear strain in a manner analogous to yield stress measurement in a uniaxial tensile test. The correlation between shear yield and uniaxial yield was altered by this new yield measurement technique, but the new correlation was not as greatly improved as was suggested would occur from the FEA study.

  12. Validation of the shear punch-tensile correlation technique using irradiated materials

    SciTech Connect

    Hankin, G.L.; Faulkner, R.G.; Toloczko, M.B.; Hamilton, M.L.

    1998-03-01

    It was recently demonstrated that tensile data could be successfully related to shear punch data obtained on transmission electron microscopy (TEM) discs for a variety of irradiated alloys exhibiting yield strengths that ranged from 100 to 800 MPa. This implies that the shear punch test might be a viable alternative for obtaining tensile properties using a TEM disk, which is much smaller than even the smallest miniature tensile specimens, especially when irradiated specimens are not available or when they are too radioactive to handle easily. The majority of the earlier tensile-shear punch correlation work was done using a wide variety of unirradiated materials. The current work extends this correlation effort to irradiated materials and demonstrates that the same relationships that related shear punch tests remain valid for irradiated materials. Shear punch tests were performed on two sets of specimens. In the first group, three simple alloys from the {sup 59}Ni isotopic doping series in the solution annealed and cold worked conditions were irradiated at temperatures ranging from 365 to 495 C in the Fast Flux Test Facility. The corresponding tensile data already existed for tensile specimens fabricated from the same raw materials and irradiated side-by-side with the disks. In the second group, three variants of 316 stainless steel were irradiated in FFTF at 5 temperatures between 400 and 730 C to doses ranging from 12.5 to 88 dpa. The specimens were in the form of both TEM and miniature tensile specimens and were irradiated side-by-side.

  13. Miniature specimen shear punch test for UHMWPE used in total joint replacements.

    PubMed

    Kurt, S M; Jewett, C W; Bergström, J S; Foulds, J R; Edidin, A A

    2002-05-01

    Despite the critical role that shear is hypothesized to play in the damage modes that limit the performance of total hip and knee replacements, the shear behavior of ultra-high molecular weight polyethylene (UHMWPE) remains poorly understood, especially after oxidative degradation or radiation crosslinking. In the present study, we developed the miniature specimen (0.5 mm thickness x 6.4mm diameter) shear punch test to evaluate the shear behavior of UHMWPE used in total joint replacement components. We investigated the shear punch behavior of virgin and crosslinked stock materials, as well as of UHMWPE from tibial implants that were gamma-irradiated in air and shelf aged for up to 8.5 years. Finite element analysis, scanning electron microscopy, and interrupted testing were conducted to aid in the interpretation of the shear punch load-displacement curves. The shear punch load-displacement curves exhibited similar distinctive features. Following toe-in, the load-displacement curves were typically bilinear, and characterized by an initial stiffness, a transition load, a hardening stiffness, and a peak load. The finite element analysis established that the initial stiffness was proportional to the elastic modulus of the UHMWPE, and the transition load of the bilinear curve reflected the development of a plastically deforming zone traversing through the thickness of the sample. Based on our observations, we propose two interpretations of the peak load during the shear punch test: one theory is based on the initiation of crystalline plasticity, the other based on the transition from shear to tension during the tests. Due to the miniature specimen size, the shear punch test offers several potential advantages over bulk test methods, including the capability to directly measure shear behavior, and quite possibly infer ultimate uniaxial behavior as well, from shelf aged and retrieved UHMWPE components. Thus, the shear punch test represents an effective and complementary

  14. The development of a tensile-shear punch correlation for yield properties of model austenitic alloys

    SciTech Connect

    Hankin, G.L.; Faulkner, R.G.; Hamilton, M.L.; Garner, F.A.

    1997-08-01

    The effective shear yield and maximum strengths of a set of neutron-irradiated, isotopically tailored austentic alloys were evaluated using the shear punch test. The dependence on composition and neutron dose showed the same trends as were observed in the corresponding miniature tensile specimen study conducted earlier. A single tensile-shear punch correlation was developed for the three alloys in which the maximum shear stress or Tresca criterion was successfully applied to predict the slope. The correlation will predict the tensile yield strength of the three different austenitic alloys tested to within {+-}53 MPa. The accuracy of the correlation improves with increasing material strength, to within {+-} MPa for predicting tensile yield strengths in the range of 400-800 MPa.

  15. Correlation Between Shear Punch and Tensile Strength for Low-Carbon Steel and Stainless Steel Sheets

    NASA Astrophysics Data System (ADS)

    Mahmudi, R.; Sadeghi, M.

    2013-02-01

    The deformation behavior of AISI 1015 low-carbon steel, and AISI 304 stainless steel sheets was investigated by uniaxial tension and the shear punch test (SPT). Both materials were cold rolled to an 80% thickness reduction and subsequently annealed in the temperature range 25-850 °C to produce a wide range of yield and ultimate strength levels. The correlations between shear punch and tensile yield and ultimate stresses were established empirically. Different linear relationships having different slopes and intercepts were found for the low-carbon and stainless steel sheets, and the possible parameters affecting the correlation were discussed. It was shown that, within limits, yield and tensile strength of thin steel sheets can be predicted from the shear data obtained by the easy-to-perform SPT.

  16. Shear Punch Properties of Low Activation Ferritic Steels Following Irradiation in ORR

    SciTech Connect

    Ermi, Ruby M.; Hamilton, Margaret L.; Gelles, David S.; Ermi, August M.

    2001-10-01

    Shear punch post-irradiation test results are reported for a series of low activation steels containing Mn following irradiation in the Oak Ridge Reactor at 330 and 400 degrees centigrade to {approx}10 dpa. Alloy compositions included 2Cr, 9Cr and 12Cr steels with V to 1.5% and W to 1.0%. Comparison of results with tensile test results showed good correlations with previously observed trends except where disks were improperly manufactured because they were too thin or because engraving was faulty.

  17. Establishing Correlations for Predicting Tensile Properties Based on the Shear Punch Test and Vickers Microhardness data

    NASA Astrophysics Data System (ADS)

    Milot, Timothy S.

    A series of mechanical tests was performed on a matrix of pressure vessel alloys to establish correlations between shear punch tests (SPT), microhardness (Hv), and tensile data. The purpose is to estimate tensile properties from SPT and Hv data. Small specimen testing is central to characterization of irradiation-induced changes in alloys used for nuclear applications. SPT have the potential for estimating tensile yield and ultimate strengths, strain hardening and ductility data, by using TEM disks, for example. Additional insight into SPT was gained by performing finite element analysis (FEA) simulations.

  18. Effects of thermal fatigue on shear punch strength of tooth-colored restoratives

    PubMed Central

    Melody, Fam Mei Shi; U-Jin, Yap Adrian; Natalie, Tan Wei Min; Elizabeth, Tay Wan Ling; Chien, Jessica Yeo Siu

    2016-01-01

    Aims: This study investigated the effect of thermal fatigue on the shear strength of a range of tooth-colored restorative materials including giomers, zirconia-reinforced glass ionomer cement (GIC), nano-particle resin-modified GIC, highly viscous GICs, and composite resin. Materials and Methods: Twenty specimens of each material were fabricated in standardized washers (17 mm outer diameter, 9 mm internal diameter, 1 mm thick). The specimens were cured, stored in 100% humidity at 37.5°C for 24 h, and randomly divided into two groups of 10. Group A specimens were nonthermocycled (NT) and stored in distilled water at 37°C for 168 h. Group B specimens were thermocycled (TC) for 10,000 cycles (168 h) with baths X, Y, and Z adjusted to 35°C, 15°C, and 45°C, respectively. Each cycle had dwell times of 28 s in X, and 2s in Y/Z in the order XYXZ. Specimens then underwent shear punch testing at a crosshead speed of 0.5 mm/min with a 2 kN load cell. Statistical analysis of shear strength was done using t-test and two-way ANOVA/Scheffe's post hoc test at significance level P < 0.05. Results: The effect of thermal fatigue on shear strength was material dependent. Except for the “sculptable” giomer (Beautifil II) and a highly viscous GIC (Fuji IX GP Fast), no significant differences in shear strength were generally observed between the NT and TC groups. For both groups, the composite resin (Filtek Z250XT) had the highest shear strength while the zirconia-reinforced (zirconomer) and a highly viscous GIC (Ketac Molar Quick) had the lowest. Conclusions: The effect of thermocycling on shear strength was material dependent. Thermal fatigue, however, did not significantly influence the shear strength of most materials assessed. The “sculptable” composite and giomer were significantly stronger than the other materials evaluated. Shear strength of the “flowable” injectable hybrid giomer was intermediate between the composite and GICs. PMID:27563182

  19. The study of adiabatic shear band instability in a pearlitic 4340 steel using a dynamic punch test

    SciTech Connect

    Zurek, A.K. )

    1994-11-01

    At low strain rates and moderate levels of strain, slip and twinning are the most common deformation mechanisms in metals and alloys. Both mechanisms are highly correlated with the crystallography of the material. At higher strain rates and levels of strain, deformation instabilities, such as adiabatic shear bands (ASB), may develop. These bands are planar in nature, and their formation is related more to the specimen geometry, deformation process, and mechanical properties of a material than to its local crystallography. The formation of adiabatic shear band instabilities in a pearlitic 4340 steel using a dynamic punch test has been studied. The dynamic punch-impact test produced white-etching adiabatic shear bands. The average strain of 0.5 was sufficient to produce adiabatic shear bands in this steel at an average strain rate of 18,000 s[sup [minus]1]. Nanohardness variations found across the adiabatic shear at an average strain rate of 18,000 s[sup [minus]1]. Nanohardness variations found across the adiabatic shear band are thought to be caused by the fragmentation and spheriodization of the Fe[sub 3]C and the overall deformation and work hardening of the pearlitic microstructure. The cracks formed at the termination of the adiabatic shear band caused the sample to fracture in a ductile mode.

  20. Criteria for initiation of delamination in quasi-static punch-shear tests of a carbon-fiber composite material.

    SciTech Connect

    Chin, Eric Brian; English, Shawn Allen; Briggs, Timothy

    2015-09-01

    V arious phenomenological delamination initiation criteria are analyzed in quasi - static punch - shear tests conducted on six different geometries. These six geometries are modeled and analyzed using elastic, large - deformation finite element analysis. Analysis output is post - processed to assess different delamination initiation criteria, and their applicability to each of the geometries. These criteria are compared to test results to assess whether or not they are appropriate based on what occurred in testing. Further, examinations of CT scans and ultrasonic images o f test specimens are conducted in the appendix to determine the sequence of failure in each test geometry.

  1. Shear punch testing of 59Ni isotopically-doped model austenitic alloys after irradiation in FFTF at different He/dpa ratios

    NASA Astrophysics Data System (ADS)

    Hankin, G. L.; Toloczko, M. B.; Hamilton, M. L.; Garner, F. A.; Faulkner, R. G.

    1998-10-01

    In this last of a series of papers describing the evolution of microstructure, void swelling and mechanical properties of model austenitic alloys in response to differences in helium/dpa rates, shear punch testing is used to assess the relative effect of helium generation ratios and various important material and environmental variables. Shear punch data confirm the general trends observed in earlier tensile data derived from the 59Ni isotopic doping experiment. There is a convergence to a common saturation level of yield strength that depends on alloy composition, temperature and displacement rate, but not on starting condition. The approach to saturation can be sensitive to helium/dpa ratio, however, and may depend on the starting state. For reasons not yet known, shear punch tests appear to be more sensitive to such transient differences than are tensile tests.

  2. Shear punch testing of candidate reactor materials after irradiation in fast reactors and spallation environments

    NASA Astrophysics Data System (ADS)

    Maloy, S. A.; Romero, T. J.; Hosemann, P.; Toloczko, M. B.; Dai, Y.

    2011-10-01

    Ferritic/martensitic steels and nickel-base superalloys are potential materials for use in spallation targets and fusion and fast reactors. To investigate the effects of irradiation on these materials, tests were performed after irradiation in the high energy proton beam at the Paul Scherrer Institute (SINQ Target Irradiation Program (STIP), 570 MeV), as well on specimens obtained from a driver duct irradiated in the Fast Flux Test Facility (FFTF). Dose accumulations were up to 18 dpa for STIP irradiations (at 147-406 °C) and up to 155 dpa in FFTF (at 383-505 °C). The helium/dpa ratios ranged from 0.2 to 80 appm/dpa. Mechanical testing was performed at 25 °C. Increases in shear yield and shear maximum stress with increasing dose mirrored the results observed from companion tensile tests.

  3. 29 CFR 570.59 - Occupations involved in the operation of power-driven metal forming, punching, and shearing...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... area between the dies; power presses; and plate punches. (iii) All bending machines, such as apron..., which change the shape of or cut metal by means of tools, such as dies, rolls, or knives which...

  4. 29 CFR 570.59 - Occupations involved in the operation of power-driven metal forming, punching, and shearing...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... area between the dies; power presses; and plate punches. (iii) All bending machines, such as apron..., which change the shape of or cut metal by means of tools, such as dies, rolls, or knives which...

  5. Reconstruction of large wounds using a combination of negative pressure wound therapy and punch grafting after excision of acral lentiginous melanoma on the foot.

    PubMed

    Seo, Jimyung; Kim, Jihee; Nam, Kyoung Ae; Zheng, Zhenlong; Oh, Byung Ho; Chung, Kee Yang

    2016-01-01

    Melanoma in darker-pigmented individuals often develops in an acral lentiginous fashion on the foot. After surgical removal of a tumor at this site, repair of the wound can be challenging. This is because there is an insufficient local skin pool and lack of mobility of the skin in this area. Moreover, functional aspects such as walking and weight bearing should be considered. We performed a combination treatment of negative pressure wound therapy (NPWT) and punch grafting on 15 patients, after wide excision of acral lentiginous melanomas on the foot, and compared these to 26 patients who underwent either secondary intention healing (SIH, n = 13) or NPWT (n = 13) alone. The punch grafting with NPWT group showed significantly shorter healing times than those of the other two groups. Evaluation of completely healed wounds using the Vancouver Burn Scar Assessment Scale revealed that the punch grafting group had mean values better, or comparable, to the SIH or NPWT group in four of the five scales (except pigmentation). As for complications, only one patient developed a wound infection after punch grafting. Further, by utilizing NPWT for fixation of punch grafts, it was possible to treat all subjects as outpatients after punch grafting. These results show that a combination treatment of NPWT and punch grafting is an excellent therapeutic option for post-wide excision wounds on the feet, with significantly shortened healing times and favorable cosmetic outcomes. PMID:26173565

  6. Shear punch testing of {sup 59}Ni isotopically-doped model austenitic alloys after irradiation in FFTF at different He/dpa ratios

    SciTech Connect

    Hankin, G.L.; Faulkner, R.G.; Hamilton, M.L.; Garner, F.A.

    1998-03-01

    A series of three model alloys, Fe-15Cr-25Ni, Fe-15Cr-25Ni-0.04P and Fe-15Cr45Ni were irradiated side-by-side in FFTF-MOTA in both the annealed and the cold worked condition in each of two variants, one using naturally occurring isotopic mixtures, and another doped with {sup 59}Ni to generate relatively high helium-to-dpa ratios. Previous papers in this series have addressed the influence of helium on radiation-induced evolution of microstructure, dimensional stability and mechanical properties, the latter using miniature-tensile specimens. In the final paper of this experimental series, three sets of irradiations conducted at different temperatures and displacement rates were examined by shear punch testing of standard microscopy disks. The results were used to determine the influence of helium generation rate, alloy starting condition, irradiation temperature and total neutron exposure. The results were also compared with the miniature tensile data obtained earlier. In general, all alloys approached saturation levels of strength and ductility that were relatively independent of He/dpa ratio and starting condition, but were sensitive to the irradiation temperature and total exposure. Some small influence of helium/dpa ratio on the shear strength is visible in the two series that ran at {approximately}490 C, but is not evident at 365 C.

  7. Micro-Hole Multi-Point Punching System Using Punch and Die Made by EDM

    NASA Astrophysics Data System (ADS)

    Broomfield, Mark; Mori, Toshihiko; Mikuriya, Teruaki; Tachibana, Kazushi

    In this research a multi-point micro punch and die system was developed. The process of electric discharge machining (EDM) was used to produce both the punch and die. The punches were machined from a 5 mm diameter tungsten and a 10 mm diameter tool steel round rods by wire electric discharge machining (WEDM), using a 200 µm diameter wire electrode. The die holes were made using the punch as the electrode. The EDM process of the holes was carried out on a newly developed desktop EDM machine. The punch and die placed on a micro-die set and then on a micro press were used to produce micro-holes using an automatic control system developed for this process. Experiments to produce 50 µm to 67 µm square micro-holes on 50 µm thick aluminum, 30 µm thick copper and 20 µm thick stainless steel foils were conducted. The capabilities of multi-point punching using the tungsten punch and a tool steel punch were examined and tungsten was chosen as the material of choice for making the punch tool. A scanning electron microscope confirmed that the holes produced are clean, and the sheared surfaces smooth. The punch tool showed no signs of deformation or cracks even after repeated punching.

  8. Efficacy of Punch Elevation Combined with Fractional Carbon Dioxide Laser Resurfacing in Facial Atrophic Acne Scarring: A Randomized Split-face Clinical Study

    PubMed Central

    Faghihi, Gita; Nouraei, Saeid; Asilian, Ali; Keyvan, Shima; Abtahi-Naeini, Bahareh; Rakhshanpour, Mehrdad; Nilforoushzadeh, Mohammad Ali; Hosseini, Sayed Mohsen

    2015-01-01

    Background: A number of treatments for reducing the appearance of acne scars are available, but general guidelines for optimizing acne scar treatment do not exist. The aim of this study was to compare the clinical effectiveness and side effects of fractional carbon dioxide (CO2) laser resurfacing combined with punch elevation with fractional CO2 laser resurfacing alone in the treatment of atrophic acne scars. Materials and Methods: Forty-two Iranian subjects (age range 18–55) with Fitzpatrick skin types III to IV and moderate to severe atrophic acne scars on both cheeks received randomized split-face treatments: One side received fractional CO2 laser treatment and the other received one session of punch elevation combined with two sessions of laser fractional CO2 laser treatment, separated by an interval of 1 month. Two dermatologists independently evaluated improvement in acne scars 4 and 16 weeks after the last treatment. Side effects were also recorded after each treatment. Results: The mean ± SD age of patients was 23.4 ± 2.6 years. Clinical improvement of facial acne scarring was assessed by two dermatologists blinded to treatment conditions. No significant difference in evaluation was observed 1 month after treatment (P = 0.56). Their evaluation found that fractional CO2 laser treatment combined with punch elevation had greater efficacy than that with fractional CO2 laser treatment alone, assessed 4 months after treatment (P = 0.02). Among all side effects, coagulated crust formation and pruritus at day 3 after fractional CO2 laser treatment was significant on both treatment sides (P < 0.05). Conclusion: Concurrent use of fractional laser skin resurfacing with punch elevation offers a safe and effective approach for the treatment of acne scarring. PMID:26538695

  9. Punch card programmable microfluidics.

    PubMed

    Korir, George; Prakash, Manu

    2015-01-01

    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series of holes in punched paper tapes, we demonstrate independent control of 15 on-chip pumps with enhanced mixing, normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word "PUNCHCARD MICROFLUIDICS" using the droplet generator. Multiplexing is demonstrated by implementing an example colorimetric water quality assays for pH, ammonia, nitrite and nitrate content in different water samples. With its portable and robust design, low cost and ease-of-use, we envision punch card programmable microfluidics will bring complex control of microfluidic chips into field-based applications in low-resource settings and in the hands of children around the world. PMID:25738834

  10. Punch Card Programmable Microfluidics

    PubMed Central

    Korir, George; Prakash, Manu

    2015-01-01

    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series of holes in punched paper tapes, we demonstrate independent control of 15 on-chip pumps with enhanced mixing, normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word “PUNCHCARD MICROFLUIDICS” using the droplet generator. Multiplexing is demonstrated by implementing an example colorimetric water quality assays for pH, ammonia, nitrite and nitrate content in different water samples. With its portable and robust design, low cost and ease-of-use, we envision punch card programmable microfluidics will bring complex control of microfluidic chips into field-based applications in low-resource settings and in the hands of children around the world. PMID:25738834

  11. Aerospace Threaded Fastener Strength in Combined Shear and Tension Loading

    NASA Technical Reports Server (NTRS)

    Steeve, B. E.; Wingate, R. J.

    2012-01-01

    A test program was initiated by Marshall Space Flight Center and sponsored by the NASA Engineering and Safety Center to characterize the failure behavior of a typical high-strength aerospace threaded fastener under a range of shear to tension loading ratios for both a nut and an insert configuration where the shear plane passes through the body and threads, respectively. The testing was performed with a customized test fixture designed to test a bolt with a single shear plane at a discrete range of loading angles. The results provide data to compare against existing combined loading failure criteria and to quantify the bolt strength when the shear plane passes through the threads.

  12. A technique for combined dynamic compression-shear test

    NASA Astrophysics Data System (ADS)

    Zhao, P. D.; Lu, F. Y.; Chen, R.; Lin, Y. L.; Li, J. L.; Lu, L.; Sun, G. L.

    2011-03-01

    It is critically important to study the dynamic response of materials under a combined compression-shear loading for developing constitutive laws more accurately and fully. We present a novel technique to achieve the combined compression and shear loadings at high strain rates. The main apparatus consists of a strike bar, an incident bar, and two transmission bars. The close-to-specimen end of the incident bar is wedge-shaped with 90°. In each experiment, there are two identical specimens, respectively, agglutinated between one side of the wedge and one of transmission bars. When a loading impulse travels to specimens along the incident bar, because of the special geometrical shape, the specimen-incident bar interface gets an axial and a transverse velocity. Specimens endure a combined compression-shear loading at high strain rates. The compression stress and strain of the specimens are deduced from signals recorded by strain gages mounted on the bars. The shear stress is measured by two piezoelectric transducers of quartz (Y-cut with rotation angle 17.7°) embedded at the close-to-specimen end of transmission bars; the shear strain is measured with a novel optical technique, which is based on the luminous flux method. An analytic model was proposed and validated by the numerical simulations. The simulation results yield good agreement with the analytic results. The proposed technique was then validated through experiments carried out on lead specimens, by comparing experimental results with that of the split Hopkinson pressure bar experiments.

  13. 46. June 1974. BLACKSMITH SHOP, VIEW LOOKING SOUTHEAST, SHOWING PUNCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. June 1974. BLACKSMITH SHOP, VIEW LOOKING SOUTHEAST, SHOWING PUNCH AND SHEAR MACHINE IN CENTER. - Gruber Wagon Works, Pennsylvania Route 183 & State Hill Road at Red Bridge Park, Bernville, Berks County, PA

  14. 41. Detail of punch press on left and large metal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. Detail of punch press on left and large metal plate shear, Boiler Shop, located in north end of Machine Shop Building. - Thames Tow Boat Company, Foot of Farnsworth Street, New London, New London County, CT

  15. Shear strength of irradiated insulation under combined shear/compression loading

    SciTech Connect

    Reed, R.; Fabian, P.; Hazelton, C.

    1997-06-01

    The shear strengths of irradiated insulation systems were measured at 4 K under combined shear and compression loads. Sandwich-type (316LN/bonded insulation/316LN) specimens were irradiated at 4 K and tested at 4 K after storage at room temperature. Some specimens were stored at room temperature; others, at 77 K. Insulation systems included diglycidylether of bisphenol-A and tetraglycidyl diaminodiphenyl methane epoxies and polyimide resins reinforced with S-2 glass. Some contained polyimide film or mica electrical barriers. All specimens were irradiated to a fast neutron fluence of 1.8 X 10{sup 22} n/m{sup 2}. Insulation systems are compared on the basis of their irradiated and unirradiated shear strengths.

  16. High resolution weak lensing mass mapping combining shear and flexion

    NASA Astrophysics Data System (ADS)

    Lanusse, F.; Starck, J.-L.; Leonard, A.; Pires, S.

    2016-06-01

    Aims: We propose a new mass mapping algorithm, specifically designed to recover small-scale information from a combination of gravitational shear and flexion. Including flexion allows us to supplement the shear on small scales in order to increase the sensitivity to substructures and the overall resolution of the convergence map without relying on strong lensing constraints. Methods: To preserve all available small scale information, we avoid any binning of the irregularly sampled input shear and flexion fields and treat the mass mapping problem as a general ill-posed inverse problem, which is regularised using a robust multi-scale wavelet sparsity prior. The resulting algorithm incorporates redshift, reduced shear, and reduced flexion measurements for individual galaxies and is made highly efficient by the use of fast Fourier estimators. Results: We tested our reconstruction method on a set of realistic weak lensing simulations corresponding to typical HST/ACS cluster observations and demonstrate our ability to recover substructures with the inclusion of flexion, which are otherwise lost if only shear information is used. In particular, we can detect substructures on the 15'' scale well outside of the critical region of the clusters. In addition, flexion also helps to constrain the shape of the central regions of the main dark matter halos. Our mass mapping software, called Glimpse2D, is made freely available at http://www.cosmostat.org/software/glimpse

  17. A punch drunk jockey?

    PubMed

    McCrory, P; Turner, M; Murray, J

    2004-06-01

    The case is reported of a retired professional jockey with progressive memory loss. The concern is that he may be suffering from chronic traumatic encephalopathy or the "punch drunk syndrome". PMID:15155454

  18. Punching Deterioration Mechanism of Magnetic Properties of Cores

    NASA Astrophysics Data System (ADS)

    Kaido, Chikara; Mogi, Hisashi; Fujikura, Masahiro; Yamasaki, Jiro

    This paper discusses the deterioration mechanism of magnetic properties of cores due to punching and proposes the modeling, as the best design of motors, considering manufacturing motors, is important in order to improve the high performance of motors corresponding to energy saving. In producing motors, magnetic cores with laminated steel sheets are made of punched sheets, and then the magnetic properties of steel sheets are deteriorated by plastic deformation and the induced residual stress due to punching. In this paper, the punching deterioration mechanism is investigated by observing magnetic domains at steel surfaces near sheared parts. Tensile and compressive stresses induced at cut steel edges deteriorate the magnetic properties of punched steel sheets in high flux densities as the compression deterioration is stronger than the tension improvement, and improve permeabilities at low magnetic field because the increases in permeabilities with tensile stresses are emphasized. Therefore, it is necessary to model the magnetic properties of motor magnetic cores, taking account of these magnetic phenomena.

  19. Sun Packs Double Punch

    NASA Video Gallery

    On August 3, the sun packed a double punch, emitting a M6.0-class flare at 9:43 am EDT. This video is of the second, slightly stronger M9.3-class flare at 11:41 pm EDT. Both flares had significant ...

  20. Punching Holes in Thin Metals

    NASA Technical Reports Server (NTRS)

    Garcia, Richard; Foster, Derrell; Miranda, Valentino

    1987-01-01

    Simple punching tool used to make holes in thin metal sheets, without burrs and edge deformations. Tool used on such materials as stainless steel, nickel alloys, beryllium, copper, and aluminum, in thicknesses of 0.002 to 0.010 in. With new punch, hole size held to tolerance of 0.025 mm. Includes rubber punch extruding into hole in top plate, pushing out exposed portion of clamped metal sheet.

  1. Combined Ideal and Kinetic Effects on Reversed Shear Alfven Eigenmodes

    SciTech Connect

    N.N. Gorelenkov, G.J. Kramer, and R. Nazikian

    2011-05-23

    A theory of Reversed Shear Alfven Eigenmodes (RSAEs) is developed for reversed magnetic field shear plasmas when the safety factor minimum, qmin, is at or above a rational value. The modes we study are known sometimes as either the bottom of the frequency sweep or the down sweeping RSAEs. We show that the ideal MHD theory is not compatible with the eigenmode solution in the reversed shear plasma with qmin above integer values. Corrected by special analytic FLR condition MHD dispersion of these modes nevertheless can be developed. Large radial scale part of the analytic RSAE solution can be obtained from ideal MHD and expressed in terms of the Legendre functions. The kinetic equation with FLR effects for the eigenmode is solved numerically and agrees with the analytic solutions. Properties of RSAEs and their potential implications for plasma diagnostics are discussed.

  2. Critical combinations of shear and direct axial stress for curved rectangular panels

    NASA Technical Reports Server (NTRS)

    Schildcrout, Murry; Stein, Manuel

    1949-01-01

    A solution is presented for the problem of the buckling of curved rectangular panels subjected to combined shear and direct axial stress. Charts giving theoretical critical combinations of shear and direct axial stress are presented for panels having five different length-width ratios. Because the actual critical compressive stress of rectangular panels having substantial curvature is known to be much lower than the theoretical value, a semiempirical method of analysis of curved panels subjected to combined shear and direct axial stress is presented for use in design. (author

  3. Portable punch and die jig

    DOEpatents

    Lewandowski, Edward F.; Anderson, Petrus A.

    1978-01-01

    A portable punch and die jig includes a U-shaped jig of predetermined width having a slot of predetermined width in the base thereof extending completely across the width of the jig adapted to fit over the walls of rectangular tubes and a punch and die assembly disposed in a hole extending through the base of the jig communicating with the slot in the base of the jig for punching a hole in the walls of the rectangular tubes at precisely determined locations.

  4. 21 CFR 882.4750 - Skull punch.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Skull punch. 882.4750 Section 882.4750 Food and... NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is a device used to punch holes through a patient's skull to allow fixation of cranioplasty plates...

  5. 21 CFR 882.4750 - Skull punch.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Skull punch. 882.4750 Section 882.4750 Food and... NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is a device used to punch holes through a patient's skull to allow fixation of cranioplasty plates...

  6. 21 CFR 882.4750 - Skull punch.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Skull punch. 882.4750 Section 882.4750 Food and... NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is a device used to punch holes through a patient's skull to allow fixation of cranioplasty plates...

  7. 21 CFR 882.4750 - Skull punch.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Skull punch. 882.4750 Section 882.4750 Food and... NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is a device used to punch holes through a patient's skull to allow fixation of cranioplasty plates...

  8. 21 CFR 882.4750 - Skull punch.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Skull punch. 882.4750 Section 882.4750 Food and... NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is a device used to punch holes through a patient's skull to allow fixation of cranioplasty plates...

  9. Combined compressive and shear buckling analysis of hypersonic aircraft structural sandwich panels

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Jackson, Raymond H.

    1991-01-01

    The combined-load (compression and shear) buckling equations were established for orthotropic sandwich panels by using the Rayleigh-Ritz method to minimize the panel total potential energy. The resulting combined-load buckling equations were used to generate buckling interaction curves for super-plastically-formed/diffusion-bonded titanium truss-core sandwich panels and titanium honeycomb-core sandwich panels having the same specific weight. The relative combined-load buckling strengths of these two types of sandwich panels are compared with consideration of their sandwich orientations. For square and nearly square panels of both types, the combined load always induces symmetric buckling. As the panel aspect ratios increase, antisymmetric buckling will show up when the loading is shear-dominated combined loading. The square panel (either type) has the highest combined buckling strength, but the combined load buckling strength drops sharply as the panel aspect ratio increases. For square panels, the truss-core sandwich panel has higher compression-dominated combined load buckling strength. However, for shear dominated loading, the square honeycomb-core sandwich panel has higher shear-dominated combined load buckling strength.

  10. Experimental investigation on yield behavior of PMMA under combined shear-compression loading

    NASA Astrophysics Data System (ADS)

    Zhang, Jianjun; Jin, Tao; Wang, Zhihua; Zhao, Longmao

    The work experimentally studies the yielding behavior of polymethyl methacrylate (PMMA) at three different loading rates through a developed combined shear-compression test technique which contains a universal materials testing machine, mental blocks with double beveled ends (combined shear-compression loading setup) and a column sleeve made of Teflon. The results show that the failure loci agree well with theoretical predictions involving the strain rate dependence, which indicates the validity of this test method. Additionally, the experimental data enrich the previous experimental work about polymer yielding surface in the principle stress space.

  11. Development of a boxing dynamometer and its punch force discrimination efficacy.

    PubMed

    Smith, M S; Dyson, R J; Hale, T; Janaway, L

    2000-06-01

    The development of sport-specific dynamometers is an important step towards ecological validity in analysing athlete performance. Design limitations in previous punch-measuring devices have resulted in values which may not or cannot fully reflect the force and multidirectional components in a punch. In developing this boxing dynamometer, a triaxial force measurement system and a boxing manikin interface were combined. The repeatability and accuracy of the dynamomoter were assessed using simulated straight punches. Discrimination efficacy was assessed by comparison of the maximal punching force of seven elite, eight intermediate and eight novice boxers during simulated boxing, throwing straight punches. For the elite, intermediate and novice groups, respectively, the maximal straight punching forces (mean +/- s(mean)) were 4800 +/- 227 N, 3722 +/- 133 N and 2381 +/- 116 N for the rear hand, and 2847 +/- 225 N, 2283 +/- 126 N and 1604 +/- 97 N for the lead hand. For all groups, maximal forces were larger for the rear than the lead hand (P < 0.001). Maximal punching force was greater in the elite than the intermediate group, and greater in the intermediate than the novice group (P < 0.05). The boxing dynamometer discriminated effectively between punching performance at three standards of performance and between the punching force of the rear and lead hands. PMID:10902679

  12. Experimental Study on Shear Response of 92.93 WT% Alumina Under Combined Pressure-Shear Loading

    NASA Astrophysics Data System (ADS)

    Yao, G. W.; Liu, Z. F.

    2007-12-01

    Pressure-shear plate impact experiments and soft recovery experiments were performed for 92.93 wt% aluminas with 75-mm-diameter compressed-gas gun. The in-material longitudinal and transverse particle velocities were traced by the embedded electromagnetic velocity gauges. The decoupled transverse particle velocities show an attenuation of shear waves with decreasing of material shear rigidity. SEM analysis of the intact samples shows heterogeneous meso-structures, and that of recovered samples shows the transit of intergranular microcracks to transgranular microcracks with increasing shock loading. The transverse shear promotes the microcracks nuclearing and expanding, and these microcracks result in remarkable dilation of alumina samples after unloading.

  13. Initiation of Polymer Bonded Explosive (PBXN-110) by Combined Shock and Shear Loading

    NASA Astrophysics Data System (ADS)

    Jordan, J. L.; Dorgan, R. J.; Nixon, M. E.; Dick, R. D.

    2007-12-01

    Combined shock and shear loading of explosives has been shown to result in detonation of explosives at input pressures less than those required with a nearly planar shock. In this study, the effect of combined shock and shear loading on PBXN-110 is investigated. The explosive sample is loaded by a TNT/Octol plane wave lens or a Pentolite pad in contact with a layer of PMMA followed by a cylindrical wave shaper that has one side angled at 45 degrees. The experiment is repeated for different thicknesses of the PMMA layer in order to vary the input pressure. In addition, the experiment is modeled using the Lagrangian finite element hydrocode EPIC, and the results of the experiments are compared with the numerical simulations.

  14. Initiation of Polymer Bonded Explosive (PBXN-110) by Combined Shock and Shear Loading

    NASA Astrophysics Data System (ADS)

    Jordan, Jennifer; Dorgan, Robert; Nixon, Michael; Dick, Richard

    2007-06-01

    Combined shock and shear loading of explosives has been shown to result in detonation of explosives at input pressures less than those required with a nearly planar shock (Cart, APS-SCCM 2003). In this study, the effect of combined shock and shear loading on PBXN-110 is investigated. The explosive sample is loaded by a TNT/Octol plane wave lens in contact with a layer of PMMA followed by a cylindrical wave shaper that has one one side angled at 45 degrees. The experiment is repeated for different thicknesses of the PMMA layer in order to vary the input pressure. In addition, the experiment is modeled using the Lagrangian finite element hydrocode EPIC, and the results of the experiments are compared with the numerical simulations.

  15. Airborne Wind Shear Detection and Warning Systems: First Combined Manufacturers' and Technologists' Conference

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1988-01-01

    The purpose of the meeting was to transfer significant, ongoing results gained during the first year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-looking technology concepts and for technologists to gain an understanding of FAA certification requirements and the problems encountered by the manufacturers during the development of airborne equipment.

  16. Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1990-01-01

    The Second Combined Manufacturers' and Technologists' Conference hosted jointly by NASA Langley (LaRC) and the Federal Aviation Administration (FAA) was held in Williamsburg, Virginia, on October 18 to 20, 1988. The purpose of the meeting was to transfer significant, ongoing results gained during the second year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  17. Airborne Wind Shear Detection and Warning Systems: Third Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1991-01-01

    The Third Combined Manufacturers' and Technologists' Conference was held in Hampton, Va., on October 16-18, 1990. The purpose of the meeting was to transfer significant on-going results of the NASA/FAA joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  18. Science in mid-Victorian Punch.

    PubMed

    Noakes, Richard

    2002-09-01

    This article examines the scientific content of the most famous comic journal of the Victorian period: Punch. Concentrating on the first three decades of the periodical (1841-1871), I show that Punch usually engaged with science that was highly topical, of consequence to the lives of its bourgeois readers, and suitable for comic interpretation. But Punch's satire of scientific topics was highly complex. It often contained allusions to non-scientific topics, and its engagement with science ranged from the utterly comic to the sharply critical. Punch prompted readers to think as well as laugh about science, and probably shaped their scientific education more than we think. PMID:12369467

  19. Transient solid-fluid interactions in rat brain tissue under combined translational shear and fixed compression.

    PubMed

    Haslach, Henry W; Leahy, Lauren N; Hsieh, Adam H

    2015-08-01

    An external mechanical insult to the brain may create internal deformation waves, which have shear and longitudinal components that induce combined shear and compression of the brain tissue. To isolate such interactions and to investigate the role of the extracellular fluid (ECF) in the transient mechanical response, translational shear stretch up to 1.25 under either 0 or 33% fixed normal compression is applied without preconditioning to heterogeneous sagittal slices which are nearly the full length of the rat brain cerebrum. The normal stress contribution is estimated by separate unconfined compression stress-stretch curves at 0.0667/s and 1/s engineering strain rates to 33% strain. Unconfined compression deformation causes lateral dimension expansion less than that predicted for an incompressible material under large deformation and often a visible loss of internal fluid from the specimen so that the bulk brain tissue is not incompressible in vitro, as sometimes assumed for mathematical modeling. The response to both slow 0.001/s and moderate 1/s shear translational stretch rates is deformation rate dependent and hardening under no compression but under 33% compression is nearly linear perhaps because of increased solid-solid friction. Both shear and normal stress relaxation are faster after the fast rate deformation possibly because higher deformation rates produce higher ECF hydrostatic pressure that primarily drives stress relaxation. The experimental results on ECF behavior guide the form of our nonlinear viscoelastic mathematical model. Our data are closely fit by non-equilibrium evolution equations that involve at most three specimen-specific empirical parameters and that are based on the idea that stretch of axons and glial processes resists load-induced ECF pressure. PMID:25913604

  20. Combined Resistivity and Shear Wave Velocity Soil-type Estimation Beneath a Coastal Protection Levee.

    NASA Astrophysics Data System (ADS)

    Lorenzo, J. M.; Goff, D.; Hayashi, K.

    2015-12-01

    Unconsolidated Holocene deltaic sediments comprise levee foundation soils in New Orleans, USA. Whereas geotechnical tests at point locations are indispensable for evaluating soil stability, the highly variable sedimentary facies of the Mississippi delta create difficulties to predict soil conditions between test locations. Combined electrical resistivity and seismic shear wave studies, calibrated to geotechnical data, may provide an efficient methodology to predict soil types between geotechnical sites at shallow depths (0- 10 m). The London Avenue Canal levee flank of New Orleans, which failed in the aftermath of Hurricane Katrina, 2005, presents a suitable site in which to pioneer these geophysical relationships. Preliminary cross-plots show electrically resistive, high-shear-wave velocity areas interpreted as low-permeability, resistive silt. In brackish coastal environments, low-resistivity and low-shear-wave-velocity areas may indicate both saturated, unconsolidated sands and low-rigidity clays. Via a polynomial approximation, soil sub-types of sand, silt and clay can be estimated by a cross-plot of S-wave velocity and resistivity. We confirm that existent boring log data fit reasonably well with the polynomial approximation where 2/3 of soil samples fall within their respective bounds—this approach represents a new classification system that could be used for other mid-latitude, fine-grained deltas.

  1. Airborne Wind Shear Detection and Warning Systems: Fourth Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Passman, Robert H. (Compiler)

    1992-01-01

    The purpose of the meeting was to transfer significant ongoing results of the NASA/FAA joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements. The present document was compiled to record the essence of the technology updates and discussions which follow each.

  2. Endothelial cell alignment as a result of anisotropic strain and flow induced shear stress combinations

    PubMed Central

    Sinha, Ravi; Le Gac, Séverine; Verdonschot, Nico; van den Berg, Albert; Koopman, Bart; Rouwkema, Jeroen

    2016-01-01

    Endothelial cells (ECs) are continuously exposed in vivo to cyclic strain and shear stress from pulsatile blood flow. When these stimuli are applied in vitro, ECs adopt an appearance resembling their in vivo state, most apparent in their alignment (perpendicular to uniaxial strain and along the flow). Uniaxial strain and flow perpendicular to the strain, used in most in vitro studies, only represent the in vivo conditions in straight parts of vessels. The conditions present over large fractions of the vasculature can be better represented by anisotropic biaxial strains at various orientations to flow. To emulate these biological complexities in vitro, we have developed a medium-throughput device to screen for the effects on cells of variously oriented anisotropic biaxial strains and flow combinations. Upon the application of only strains for 24 h, ECs (HUVECs) aligned perpendicular to the maximum principal strain and the alignment was stronger for a higher maximum:minimum principal strain ratio. A 0.55 Pa shear stress, when applied alone or with strain for 24 h, caused cells to align along the flow. Studying EC response to such combined physiological mechanical stimuli was not possible with existing platforms and to our best knowledge, has not been reported before. PMID:27404382

  3. Airborne Wind Shear Detection and Warning Systems. Second Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Spady, Amos A., Jr. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1990-01-01

    The Second Combined Manufacturers' and Technologists' Conference was hosted jointly by NASA Langley (LaRC) and the Federal Aviation Administration (FAA) in Williamsburg, Virginia, on October 18 to 20, 1988. The meeting was co-chaired by Dr. Roland Bowles of LaRC and Herbrt Schlickenmaier of the FAA. The purpose of the meeting was to transfer significant, ongoing results gained during the second year of the joint NASA/FAA Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements.

  4. Airborne Wind Shear Detection and Warning Systems. Fourth Combined Manufacturers' and Technologists' Conference, part 2

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Passman, Robert H. (Compiler)

    1992-01-01

    The Fourth Combined Manufacturers' and Technologists' Conference was hosted jointly by NASA Langley Research Center (LaRC) and the Federal Aviation Administration (FAA) in Williamsburg, Virginia, on April 14-16, 1992. The meeting was co-chaired by Dr. Roland Bowles of LaRC and Bob Passman of the FAA. The purpose of the meeting was to transfer significant ongoing results of the NASA/FAA Joint Airborne Wind Shear Program to the technical industry and to pose problems of current concern to the combined group. It also provided a forum for manufacturers to review forward-look technology concepts and for technologists to gain an understanding of the problems encountered by the manufacturers during the development of airborne equipment and the FAA certification requirements. The present document has been compiled to record the essence of the technology updates and discussions which follow each.

  5. Dislocation punching from ceramic/metal interfaces

    SciTech Connect

    Taya, M. ); Mori, T. . Dept. of Materials Science and Engineering)

    1994-07-01

    Relaxation of misfit strains at interfaces between two different materials by dislocation punching is studied analytically by focusing on two types of interfaces: planar and nonplanar. As an example of planar type interface, the case of metal coating/ceramic substrate system is studied while ceramic filler/metal matrix composite system is examined as an example of a nonplanar interface. Based on the present analytical model, the condition for dislocation punching for each interface is established. Validity of the dislocation punching model is verified by comparing the analytical results with limited experimental results, resulting in a good agreement.

  6. Mechanically fastened composite laminates subjected to combined bearing-bypass and shear loading

    NASA Technical Reports Server (NTRS)

    Madenci, Erdogan

    1993-01-01

    Bolts and rivets provide a means of load transfer in the construction of aircraft. However, they give rise to stress concentrations and are often the source and location of static and fatigue failures. Furthermore, fastener holes are prone to cracks during take-off and landing. These cracks present the most common origin of structural failures in aircraft. Therefore, accurate determination of the contact stresses associated with such loaded holes in mechanically fastened joints is essential to reliable strength evaluation and failure prediction. As the laminate is subjected to loading, the contact region, whose extent is not known, develops between the fastener and the hole boundary through this contact region, which consists of slip and no-slip zones due to friction. The presence of the unknown contact stress distribution over the contact region between the pin and the composite laminate, material anisotropy, friction between the pin and the laminate, pin-hole clearance, combined bearing-bypass and shear loading, and finite geometry of the laminate result in a complex non-linear problem. In the case of bearing-bypass loading in compression, this non-linear problem is further complicated by the presence of dual contact regions. Previous research concerning the analysis of mechanical joints subjected to combined bearing-bypass and shear loading is non-existent. In the case of bearing-bypass loading only, except for the study conducted by Naik and Crews (1991), others employed the concept of superposition which is not valid for this non-linear problem. Naik and Crews applied a linear finite element analysis with conditions along the pin-hole contact region specified as displacement constraint equations. The major shortcoming of this method is that the variation of the contract region as a function of the applied load should be known a priori. Also, their analysis is limited to symmetric geometry and material systems, and frictionless boundary conditions. Since the

  7. Cardiovascular response to punching tempo.

    PubMed

    Kravitz, Len; Greene, Larry; Burkett, Zachary; Wongsathikun, Jataporn

    2003-02-01

    Eighteen trained volunteers (12 men and 6 women: age = 22.0 +/- 2.8 years, height = 170.79 +/- 7.67 cm, weight = 71.54 +/- 12.63 kg) participated in 2-minute, randomized fitness boxing trials, wearing 0.34-kg punching gloves, at various tempos (60, 72, 84, 96, 108, and 120 b.min(-1)). During each trial, oxygen uptake (VO(2)), heart rate (HR), and ventilation (VE) were measured continuously. A rating of perceived exertion (RPE) was attained at the conclusion of each trial. Subjects were able to attain VO(2) values ranging from 26.83 to 29.75 ml.kg(-1).min(-1), which correspond to 67.7-72.5% of VO(2)max. The HR responses yielded results ranging from 167.4 to 182.2 b.min(-1), or 85 to 93% of HRmax. No significant difference (p > 0.05) was seen with VO(2) between trials, although a significant difference (p < 0.05) was observed with HR, VE, and RPE. It appears that boxing speed is associated with increased VE, HR response, and perceived effort but not with VO(2). Energy expenditure values ranged from 9.8 to 11.2 kcal.min(-1) for the boxing trials. These results suggest that fitness boxing programs compare favorably with other exercise modalities in cardiovascular response and caloric expenditure. PMID:12580664

  8. Protein denaturation by combined effect of shear and air-liquid interface.

    PubMed

    Maa, Y F; Hsu, C C

    1997-06-20

    The effect of shear alone on the aggregation of recombinant human growth hormone (rhGH) and recombinant human deoxyribonuclease (rhDNase) has been found to be insignificant. This study focused on the synergetic effect of shear and gas-liquid interface on these two model proteins. Two shearing systems, the concentric-cylinder shear device (CCSD) and the rotor/stator homogenizer, were used to generate high shear (> 10(6)) in aqueous solutions in the presence of air. High shear in the presence of an air-liquid interface had no major effect on rhDNase but caused rhGH to form noncovalent aggregates. rhGH aggregation was induced by the air-liquid interface and was found to increase with increasing protein concentration and the air-liquid interfacial area. The aggregation was irreversible and exhibited a first-order kinetics with respect to the protein concentration and air-liquid interfacial area. Shear and shear rate enhanced the interaction because of its continuous generation of new air-liquid interfaces. In the presence of a surfactant, aggregation could be delayed or prevented depending upon the type and the concentration of the surfactant. The effect of air-liquid interface on proteins at low shear was examined using a nitrogen bubbling method. We found that foaming is very detrimental to rhGH even though the shear involved is low. The use of anti-foaming materials could prevent rhGH aggregation during bubbling. The superior stability exhibited by rhDNase may be linked to the higher surface tension and lower foaming tendency of its aqueous solution. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 503-512, 1997. PMID:18636406

  9. Critical combinations of shear and transverse direct stress for an infinitely long flat plate with edges elastically restrained against rotation

    NASA Technical Reports Server (NTRS)

    Batdorf, S B; Houbolt, John C

    1946-01-01

    An exact solution and a closely concurring approximate energy solution are given for the buckling of an infinitely long flat plate under combined shear and transverse direct stress with edges elastically restrained against rotation. It was found that an appreciable fraction of the critical stress in pure shear may be applied to the plate without any reduction in the transverse compressive stress necessary to produce buckling. An interaction formula in general use was shown to be decidedly conservative for the range in which it is supposed to apply.

  10. Dynamic flow localization in porous rocks under combined pressure and shear loading

    NASA Astrophysics Data System (ADS)

    Yarushina, Viktoriya; Podladchikov, Yuri; Simon, Nina

    2015-04-01

    Flow localization occurs in deforming porous fluid saturated rocks. It exhibits itself as veins, pockmarks on the ocean floor or gas chimneys visible on seismic images from several chalk fields of the Central North Sea and from the Utsira formation at Sleipner in the Norwegian North Sea, which is one of the best documented CO2 storage sites. Porosity waves were repeatedly shown to be a viable mechanism of flow self-localization that does not require the pre-existence of a connected fracture network. Porosity waves result from an instability of the Darcy flow that occurs in porous rocks with time-dependent viscous or viscoelastoplastic rheology. Local fluid overpressure generated by fluid injection or chemical reactions aided by buoyancy force drives upward fluid migration. Viscous deformation delays pressure diffusion thus maintaining local overpressure for considerable periods of time. Development of an under-pressured region just below the over-pressured domain leads to separation of the fluid-filled high-porosity blob from the source and the background flow. The instability organizes the flow into separate vertical channels. Pressure distribution, shape and scaling of these channels are highly sensitive to the rheology of the porous rock. In this contribution, based on a micromechanical approach, we consider the complex rheology of brittle, ductile and transitional regimes of deformation of porous rocks in the presence of combined pressure and shear loading. Accurate description of transitional brittle-ductile deformation is a challenging task due to a large number of microscopic processes involved. We use elastoplastic and viscoplastic analytical solutions for the non-hydrostatic deformation of a singular cavity in the representative volume element in order to deduce expected behavior of the porous rock. The model provides micro-mechanisms for various failure modes (localized and homogeneous) and dilatancy onset. In particular, the model predicts that dilatancy

  11. Best way to perform a punch biopsy.

    PubMed

    Domínguez-Cherit, Judith; Gutiérrez Mendoza, Daniela

    2015-04-01

    Nail punch biopsy is used to obtain a tissue sample for the diagnosis and treatment of nail diseases. The best results will be possible if the surgeon is familiar with the anatomy and physiology of the nail apparatus. A punch biopsy can be used in all regions of the nail apparatus in the presence or absence of nail plate. When the procedure is performed with a careful handling of the anatomic site and specimen, in most cases a successful diagnosis can be achieved. PMID:25828717

  12. Wiring harnesses documented by punched-card technique

    NASA Technical Reports Server (NTRS)

    Hicks, W. W.; Kloezeman, W. G.

    1970-01-01

    Cards representing a connector are punched, sorted, and then used to printout wiring documentation for that connector. When wiring changes are made, new cards are punched and the wiring documentation is reprinted to reflect the latest configuration.

  13. Combined Effect of Shear and Fibrous Fillers on Orientation-Induced Crystallization in Discontinuous Aramid Fiber-Isotactic Polypropylene Composites

    SciTech Connect

    Larin,B.; Avila-Orta, C.; Somani, R.; Hsiao, B.; Marom, G.

    2008-01-01

    The shear-induced crystallization behavior in isotactic polypropylene (iPP) composite melt containing short aramid fibers was investigated by means of WAXD (wide-angle X-ray diffraction) and SAXS (small-angle X-ray scattering) techniques using synchrotron radiation. The study was carried out in a post-shear isothermal crystallization mode at temperatures of 140-160 C. Parameters pertaining to the crystallization morphology and kinetics were analyzed, including total crystallinity, orientated crystalline and amorphous fractions, dimensions of the formed shish-kebab structure, as well as induction time and rate of crystallization. The individual contributions of shear and fibers were evaluated and the combined effect was compared. The results clearly indicated that the effect is synergistic rather than additive.

  14. Amplitude-modulated ultrasound radiation force combined with phase-sensitive optical coherence tomography for shear wave elastography

    NASA Astrophysics Data System (ADS)

    Nguyen, Thu-Mai; Song, Shaozhen; Arnal, Bastien; Wong, Emily Y.; Shen, Tueng T.; Wang, Ruikang K.; O'Donnell, Matthew

    2015-03-01

    Tissue stiffness can be measured from the propagation speed of shear waves. Acoustic radiation force (ARF) can generate shear waves by focusing ultrasound in tissue for ~100 μs. Safety considerations and electronics abilities limit ultrasound pressures. We previously presented shear wave elastography combining ARF and phase-sensitive optical coherence tomography (PhS-OCT) [1]. Here, we use amplitude-modulated ARF to enhance shear wave signal-to-noise ratio (SNR) at low pressures. Experiments were performed on tissue-mimicking phantoms. ARF was applied using a single-element transducer, driven by a 7.5 MHz, 3-ms, sine wave modulated in amplitude by a linear-swept frequency (1 to 7 kHz). Pressures between 1 to 3 MPa were tested. Displacements were tracked using PhS-OCT and numerically compressed using pulse compression methods detailed in previous work [2]. SNR was compared to that of 200-μs bursts. Stiffness maps were reconstructed using time-of-flight computations. 200-μs bursts give barely detectable displacements at 1 MPa (3.7 dB SNR). Pulse compression gives 36.2 dB at 1.5 MPa. In all cases with detectable displacements, shear wave speeds were determined in 5%-gelatin and 10%-gelatin phantoms and compared to literature values. Applicability to ocular tissues (cornea, intraocular lens) is under investigation.

  15. A MEMS thermal shear stress sensor produced by a combination of substrate-free structures with anodic bonding technology

    NASA Astrophysics Data System (ADS)

    Ou, Yi; Qu, Furong; Wang, Guanya; Nie, Mengyan; Li, Zhigang; Ou, Wen; Xie, Changqing

    2016-07-01

    By combining substrate-free structures with anodic bonding technology, we present a simple and efficient micro-electro-mechanical system (MEMS) thermal shear stress sensor. Significantly, the resulting depth of the vacuum cavity of the sensor is determined by the thickness of the silicon substrate at which Si is removed by the anisotropic wet etching process. Compared with the sensor based on a sacrificial layer technique, the proposed MEMS thermal shear-stress sensor exhibits dramatically improved sensitivity due to the much larger vacuum cavity depth. The fabricated MEMS thermal shear-stress sensor with a vacuum cavity depth as large as 525 μm and a vacuum of 5 × 10-2 Pa exhibits a sensitivity of 184.5 mV/Pa and a response time of 180 μs. We also experimentally demonstrate that the sensor power is indeed proportional to the 1/3-power of the applied shear stress. The substrate-free structures offer the ability to precisely measure the shear stress fluctuations in low speed turbulent boundary layer wind tunnels.

  16. Punch List Process Concludes Building Project.

    ERIC Educational Resources Information Center

    Roark, Steven

    2002-01-01

    The fourteenth article in a series following a single building project (the expansion and renovation of Longview Community College's Liberal Arts Building), describes the punch list process that concludes every building project. This list delineates issues for the contractor that, when addressed, transfer responsibility to the owner. (EV)

  17. "Punch" and Elementary Education (1860-1900).

    ERIC Educational Resources Information Center

    Smith, John T.

    1998-01-01

    Discusses the formation and lifespan of the journal entitled "Punch" or the "London Charivari" that contained a variety of political cartoons and led public opinion in the 19th century. States that the journal portrayed doubts as to the direction of elementary education and showed a revulsion toward the overarching power of the school boards. (CMK)

  18. Normal mode solutions for seismo-acoustic propagation resulting from shear and combined wave point sources.

    PubMed

    Nealy, Jennifer L; Collis, Jon M; Frank, Scott D

    2016-04-01

    Normal mode solutions to range-independent seismo-acoustic problems are benchmarked against elastic parabolic equation solutions and then used to benchmark the shear elastic parabolic equation self-starter [Frank, Odom, and Collis, J. Acoust. Soc. Am. 133, 1358-1367 (2013)]. The Pekeris waveguide with an elastic seafloor is considered for a point source located in the ocean emitting compressional waves, or in the seafloor, emitting both compressional and shear waves. Accurate solutions are obtained when the source is in the seafloor, and when the source is at the interface between the fluid and elastic layers. PMID:27106346

  19. Urban shear-wave reflection seismics: Reconstruction support by combined shallow seismic and engineering geology investigations

    NASA Astrophysics Data System (ADS)

    Polom, U.; Guenther, A.; Arsyad, I.; Wiyono, P.; Krawczyk, C. M.

    2009-12-01

    After the big 2004 Sumatra-Andaman earthquake, the massive reconstruction activities in the Aceh province (Northern Sumatra) were promoted by the Republic of Indonesia and the Federal Ministry of Economic Cooperation and Development. The aims of the project MANGEONAD (Management of Georisk Nanggroe Aceh Darussalam). are to establish geoscientific on the ground support for a sustainable development and management of save building constructions, lifelines, infrastructure and also natural resources. Therefore, shallow shear-wave reflection seismics was applied in close combination to engineering geology investigations in the period between 2005-2009 since depth and internal structure of the Krueng Aceh River delta (mainly young alluvial sediments) were widely unknown. Due to the requirements in the densely populated Banda Aceh region, lacking also traffic infrastructure, a small and lightweight engineering seismic setup of high mobility and high subsurface resolution capability was chosen. The S-wave land streamer system with 48 channels was applied successfully together with the ELVIS vibratory source using S- and P-waves on paved roads within the city of Banda Aceh. The performance of the S-wave system enabled the detailed seismic investigation of the shallow subsurface down to 50-150 m depth generating shaking frequencies between 20 Hz to 200 Hz. This also provides depth information extending the maximum depths of boreholes and Standard Penetrometer Testings (SPT), which could only be applied to max. 20 m depth. To integrate the results gained from all three methods, and further to provide a fast statistical analysis tool for engineering use, the Information System Engineering Geology (ISEG, BGR) was developed. This geospatial information tool includes the seismic data, all borehole information, geotechnical SPT and laboratory results from samples available in the investigation area. Thereby, the geotechnical 3D analysis of the subsurface units is enabled. The

  20. Airborne Wind Shear Detection and Warning Systems: Third Combined Manufacturers' and Technologists' Conference, part 1

    NASA Technical Reports Server (NTRS)

    Vicroy, Dan D. (Compiler); Bowles, Roland L. (Compiler); Schlickenmaier, Herbert (Compiler)

    1991-01-01

    Papers presented at the conference on airborne wind shear detection and warning systems are compiled. The following subject areas are covered: terms of reference; case study; flight management; sensor fusion and flight evaluation; Terminal Doppler Weather Radar data link/display; heavy rain aerodynamics; and second generation reactive systems.

  1. Punch for use in a pellet press

    SciTech Connect

    Beuchel, P.H.

    1991-06-18

    This paper describes an apparatus for producing substantially uniform cylindrical uranium dioxide pellets with frusto-conical beveled ends useful for forming nuclear reactor fuel. It comprises: a pair of reciprocating punch means for compressing and shaping granular uranium dioxide into the frusto-conical beveled end cylindrical pellets, each the punch means including a substantially flat face with a chamfered circumferential edge, wherein the face and the chamfered edge are formed from a substantially chip resistance alloy consisting essentially of substantially pure tungsten carbide having a grain size of less than one micron and 16.5 to 17.5% by weight cobalt and the substantially chip resistant alloy is substantially devoid of impurity interfaces.

  2. Targeted cryotherapy using disposable biopsy punches.

    PubMed

    Prasad, Avitus John Raakesh

    2014-04-01

    Cryotherapy is a commonly used office procedure that causes destruction of tissue by cryonecrosis due to rapid freezing and thawing of cells. The limitation in treating plantar warts and deeper dermal lesions is that the freeze time should be longer to penetrate deeper, which results in collateral damage to normal skin surrounding the lesion. This results in unwanted side effects of prolonged pain, blistering and haemorrhage and increased healing time. The cone spray technique was used to reduce collateral damage, but deeper penetration is difficult to achieve. An innovative technique using disposable biopsy punches is described that ensures deeper freezing as compared to the plastic cone. The metal cutting edge of the punch enters deeper into the lesions as the liquid nitrogen is passed, sparing damage to surrounding skin. PMID:25136216

  3. Targeted Cryotherapy Using Disposable Biopsy Punches

    PubMed Central

    Prasad, Avitus John Raakesh

    2014-01-01

    Cryotherapy is a commonly used office procedure that causes destruction of tissue by cryonecrosis due to rapid freezing and thawing of cells. The limitation in treating plantar warts and deeper dermal lesions is that the freeze time should be longer to penetrate deeper, which results in collateral damage to normal skin surrounding the lesion. This results in unwanted side effects of prolonged pain, blistering and haemorrhage and increased healing time. The cone spray technique was used to reduce collateral damage, but deeper penetration is difficult to achieve. An innovative technique using disposable biopsy punches is described that ensures deeper freezing as compared to the plastic cone. The metal cutting edge of the punch enters deeper into the lesions as the liquid nitrogen is passed, sparing damage to surrounding skin. PMID:25136216

  4. Behavior of Three Metallic Alloys under Combined Axial-Shear Stresses at Elevated Temperature

    NASA Technical Reports Server (NTRS)

    Colaiuta, J. F.; Lissenden, C. J.; Lerch, B. A.

    2003-01-01

    Type 316 stainless steel, Haynes 188, and Inconel 718 samples were subjected to an axial-shear strain controlled loading history while the specimen temperature was held at 650 C to quantify the evolution of material state under a complex biaxial load path when the material is in the viscoplastic domain. Yield surfaces were constructed in the axial-shear stress plane using a sensitive, 30 x 10(exp -6)m/m, equivalent offset strain definition for the yield strain. Subsequent yield surfaces were constructed at various points along the strain path to define the material evolution. These subsequent yield surface translated, expanded, and distorted relative to the initial yield surface. Each of these very different materials exhibited components of isotropic, kinematic and distortional hardening. Furthermore, subsequent yield surfaces for each material have a very well defined front face and a poorly defined, flattened, back side.

  5. Insights into the movements of landslides from combinations of field monitoring and novel direct shear testing

    NASA Astrophysics Data System (ADS)

    Petley, D. N.; Carey, J.; Massey, C. I.; Brain, M.

    2015-12-01

    The mechanisms of pre- and post-failure movement of translational landslides remain surprisingly poorly investigated. Previous approaches have focussed on field monitoring, for example through high resolution automated surveying and/or GPS measurements, or from modelling using dedicated codes. There has been some experimental work too, most notably using ring shear devices, although there are limitations as to the type of analyses that can be completed in these devices. In recent years the author has been involved in a series of studies that have sought to understand pre- and post-failure behaviour in translational landslides using both high precision monitoring and experimental investigation using novel apparatus. The latter approach has involved the use of the back pressured shear box, a direct shear machine that allows near-infinite variation of the normal and shear stress state, and measurement and control of the pore water pressure. More recently, a more advanced version of this machine has been developed that allows dynamic loading of both direct and normal shear stresses. This paper presents key lessons learnt about the behaviour of translational landslides from these approaches. The data highlight a number of key elements: The important differences in pre-failure behaviour for materials that show a brittle response compared with those that are ductile. In particular, some aspects of behaviour (e.g. the hyperbolic acceleration to failure) can only be replicated in materials that show brittle cracking processes; In the post-failure domain, all materials show a high level of sensitivity to small changes in pore water pressure when the Factor of Safety is close to unity; Rates of strain are not simply related to pore water pressure / stress state. In particular, some materials show a different deformation response during phases of increasing pore water pressure to that during periods of pore water pressure reduction. The reasons for this require further study

  6. Noninvasive Assessment of Wall-Shear Rate and Vascular Elasticity using Combined ARFI/SWEI/Spectral Doppler Imaging System

    PubMed Central

    Dumont, Douglas M.; Doherty, Joshua R.; Trahey, Gregg E.

    2012-01-01

    The progression of atherosclerotic disease is a complex process believed to be a function of the localized mechanical properties and hemodynamic loading associated with the arterial wall. It is hypothesized that measurements of cardiovascular stiffness and wall-shear rate (WSR) may provide important information regarding vascular remodeling, endothelial function and the growth of soft lipid-filled plaques that could help a clinician better predict the occurrence of clinical events such as stroke. Two novel ARFI based imaging techniques, combined on-axis/off-axis ARFI /Spectral Doppler Imaging (SAD-SWEI) and Gated 2D ARFI/Spectral Doppler Imaging (SAD-Gated), were developed to form co-registered depictions of B-mode echogenicity, ARFI displacements, ARF-excited transverse wave velocity estimates and estimates of wall-shear rate throughout the cardiac cycle. Implemented on a commercial ultrasound scanner, the developed techniques were evaluated in tissue-mimicking and steady-state flow phantoms and compared with conventional techniques, other published study results and theoretical values. Initial in vivo feasibility of the method is demonstrated with results obtained from scanning the carotid arteries of five healthy volunteers. Cyclic variations over the cardiac cycle were observed in on-axis displacements, off-axis transverse-wave velocities and wall-shear rates. PMID:21842581

  7. Combined PIV, PLIF, and laser focal displacement measurements (LFDM) to quantify gas-liquid interfacial shear stress

    NASA Astrophysics Data System (ADS)

    McCarthy, Ian; Hann, David; Hewakandamby, Buddhika; Azzopardi, Barry

    2015-11-01

    Simultaneous Particle image velocimetry (PIV) and Planar Laser Induced Fluorescence imaging (PLIF), using a pulsed Nd:YAG laser alongside a specially design optical system to produce a pair of very fine light sheets. This equipment, coupled a dual set of high speed synchronized camera, and a combination of reflective seeding particles, fluorescent dye and tracers were used to calculate the shear stress at the gas -liquid interface by determining the velocity vectors in both phases. These quantities, along with the position and profile of the interface were found at a number of different inlet conditions. These conditions related to various flow pattern regimes commonly discussed within the literature. These regimes; stratified, stratified- wavy, 2-D and 3-D waves are seen at various liquid and gas Reynolds values, with increasing complexity occurring as higher Reynolds numbers. Validation of the results was done via computing the shear stress in a number of different ways, and also compared with result of temporal film thickness taken using the LFDM. Results from these tests show good agreement with one another and those found in literature, with determination of gas-liquid shear stress found for regimes not previously investigated in this manner. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

  8. Buckling loads for stiffened panels subjected to combined longitudinal compression and shear loadings: Results obtained with PASCO, EAL, and STAGS computer

    NASA Technical Reports Server (NTRS)

    Stroud, W. J.; Greene, W. H.; Anderson, M. S.

    1981-01-01

    The shear buckling analyses used in PASCO are summarized. The PASCO analyses include the basic VIPASA analysis, which is essentially exact for longitudinal and transverse loads, and a smeared orthotropic solution which was added to alleviate a shortcoming in the VIPASA analysis. Buckling results are presented for six stiffened panels loaded by combinations of longitudinal compression and shear. The buckling results were obtained with the PASCO, EAL, and STAGS computer programs. The EAL and STAGS solutions were obtained with a fine finite element mesh and provide calculations for the entire range of combinations of longitudinal compression and shear loadings.

  9. Modified Baha Punch Technique: Least Invasive, Shortest Time and No Suturing.

    PubMed

    Alshehri, Hassan; Alsanosi, Abdulrahman; Majdalawieh, Osama

    2016-03-01

    To describe a new Baha surgical procedure (Modified Punch Technique) with a smaller punch hole, a minimal incision and the use of the hydroxyapatite-coated abutment (BIA400). Retrospective chart review. Patients were implanted between 2012 and 2013 at King Abdulaziz University Hospital (Kingdom of Saudi Arabia). Eligible for initial or replacement bone-anchored hearing system; includes six patients (four adults, two children). Baha surgery using the Punch Method is described. The mean surgical time was 12.33 min (range 6-30), without the single outlier, it was 8.8 min. Bleeding was significant but easily controlled in two patients only. Depending on the postauricular subcutaneous thickness, the sizes of abutment used were 6, 8, 10 or 12 mm. None of the patients experienced severe pain. The postoperative follow-up period was 7 months for one patient, 5 months for three patients, and 3 months for two patients. First report of combined Modified Punch Technique with the BIA400 abutment is minimally invasive, reduces surgical time and results in faster healing and reduced likelihood of postoperative numbness. PMID:27066417

  10. Combined effects of flow-induced shear stress and electromagnetic field on neural differentiation of mesenchymal stem cells.

    PubMed

    Mascotte-Cruz, Juan Uriel; Ríos, Amelia; Escalante, Bruno

    2016-01-01

    Differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into neural phenotype has been induced by either flow-induced shear stress (FSS) or electromagnetic fields (EMF). However, procedures are still expensive and time consuming. In the present work, induction for 1 h with the combination of both forces showed the presence of the neural precursor nestin as early as 9 h in culture after treatment and this result lasted for the following 6 d. In conclusion, the use of a combination of FSS and EMF for a short-time renders in neurite-like cells, although further investigation is required to analyze cell functionality. PMID:26325339

  11. Tester automatically checks paper tape punch and reader after maintenance

    NASA Technical Reports Server (NTRS)

    Mazer, L.; Mc Murchy, D. D.

    1967-01-01

    Device automatically bench tests paper tape punches and readers in a simulated operating environment following routine maintenance. The reader and punch operate back-to-back and the paper tape output feeds the reader. The tape leader is prepunched with an arbitrary pattern that is continuously reproduced during the check.

  12. Die and telescoping punch form convolutions in thin diaphragm

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Die and punch set forms convolutions in thin dished metal diaphragm without stretching the metal too thin at sharp curvatures. The die corresponds to the metal shape to be formed, and the punch consists of elements that progressively slide against one another under the restraint of a compressed-air cushion to mate with the die.

  13. The influence of punching process on residual stress and magnetic domain structure of non-oriented silicon steel

    NASA Astrophysics Data System (ADS)

    Cao, Hongzhi; Hao, Linpo; Yi, Jingwen; Zhang, Xianglin; Luo, Zhonghan; Chen, Shenglin; Li, Rongfeng

    2016-05-01

    The main purpose of this paper is to investigate the influence of punching process on residual stress and magnetic domain structure. The residual stress in non-oriented silicon steel after punching process was measured by nanoindentation. The maximum depth was kept constant as 300 nm during nanoindentation. The material around indentation region exhibited no significant pile-up deformation. The calculation of residual stress was based on the Suresh theoretical model. Our experimental results show that residual compressive stress was generated around the sheared edge after punching. The width of residual stress affected zone by punching was around 0.4-0.5 mm. After annealing treatment, the residual stress was significantly decreased. Magnetic domain structure was observed according to the Bitter method. The un-annealed sample exhibited complicated domain patterns, and the widths of the magnetic domains varied between 3 μm and 8 μm. Most of the domain patterns of the annealed sample were 180°-domains and 90°-domains, and the widths of the domains decreased to 1-3 μm.

  14. Measuring the force of punches and kicks among combat sport athletes using a modified punching bag with an embedded accelerometer.

    PubMed

    Buśko, Krzysztof; Staniak, Zbigniew; Szark-Eckardt, Mirosława; Nikolaidis, Pantelis Theodoros; Mazur-Różycka, Joanna; Łach, Patrycja; Michalski, Radosław; Gajewski, Jan; Górski, Michał

    2016-01-01

    The main aim of the study was to design a new system to measure punching and kicking forces as well as reaction times in combat sport athletes. In addition, the study examined whether there were any intergender differences in the force of punches thrown by boxers and kicking forces delivered by taekwondo athletes. Boxers (male, n = 13; female, n = 7) were examined for the force of single straight punches and taekwondo athletes (male, n = 14; female, n = 14) for force of single Apdolio and Dwit Chagi kicks. The punching bag was equipped with acceleration transducers and gyroscopes embedded in a cylinder covered with a layer to absorb shock as well as a set of colour signal diodes. Value of the punching bag's acceleration was used for calculating: strike force; the punching location on the bag; and time of a strike. The relative error of force calculation was 3%; the relative error in acceleration measurement was less than 1%. The force of a straight rear-hand punch was greater than the force of a lead-hand punch among male and female boxers. The force of Apdolio kick delivered with a rear leg was greater compared to a lead leg among female and male taekwondo athletes. Significant gender differences were noticed in the force in both types of kicks. In boxers, intergender differences were reported only for the force of a punch thrown with the rear hand. Based on these findings, it was concluded that the modified punching bag is a good diagnostic tool for combat sports. PMID:27149957

  15. Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms.

    PubMed

    Glaßer, Sylvia; Lawonn, Kai; Hoffmann, Thomas; Skalej, Martin; Preim, Bernhard

    2014-12-01

    For an individual rupture risk assessment of aneurysms, the aneurysm's wall morphology and hemodynamics provide valuable information. Hemodynamic information is usually extracted via computational fluid dynamic (CFD) simulation on a previously extracted 3D aneurysm surface mesh or directly measured with 4D phase-contrast magnetic resonance imaging. In contrast, a noninvasive imaging technique that depicts the aneurysm wall in vivo is still not available. Our approach comprises an experiment, where intravascular ultrasound (IVUS) is employed to probe a dissected saccular aneurysm phantom, which we modeled from a porcine kidney artery. Then, we extracted a 3D surface mesh to gain the vessel wall thickness and hemodynamic information from a CFD simulation. Building on this, we developed a framework that depicts the inner and outer aneurysm wall with dedicated information about local thickness via distance ribbons. For both walls, a shading is adapted such that the inner wall as well as its distance to the outer wall is always perceivable. The exploration of the wall is further improved by combining it with hemodynamic information from the CFD simulation. Hence, the visual analysis comprises a brushing and linking concept for individual highlighting of pathologic areas. Also, a surface clustering is integrated to provide an automatic division of different aneurysm parts combined with a risk score depending on wall thickness and hemodynamic information. In general, our approach can be employed for vessel visualization purposes where an inner and outer wall has to be adequately represented. PMID:26356964

  16. Athletic fashion, "Punch," and the creation of the new woman.

    PubMed

    Collins, Tracy J R

    2010-01-01

    Between 1885-1900 "Punch" satirized the personality of the New Woman. However, virtually single-handedly it also gave a body and emancipated culture to this otherwise socially abstract personality. Using illustrations from "Punch," this essay argues that using sport specific clothing and equipment in its cartoons, "Punch" completely unintentionally created a liberating picture of women while simultaneously using its captions and border texts to make the New Woman's body signify the anxieties patriarchal culture had about her social personality and politics. PMID:21141449

  17. Fabrication of tungsten micro-punch for micro-nozzles

    NASA Astrophysics Data System (ADS)

    Lim, Hyung-Jun; Lim, Young-Mo; Kim, Soo Hyun

    2001-08-01

    A very thin electrode with a tapered shape and a cylindrical tip, named ultrathin punch, is fabricated by electrochemical etching and by controlling the vertical position of the electrode during etching. We used electrochemical etching by which we obtain punches quickly and simply. The fabrication procedure and its results are presented in this article. With this punch, we can get holes or nozzles for ink-jet printers, textile machines, and other uses. Various angles of the taper can be obtained by adjusting the immersion depth. The tip diameter also can be controlled by adjusting current density and etching time.

  18. Punch-magnet delay eliminated by modification of circuit

    NASA Technical Reports Server (NTRS)

    Cohn, C. E.

    1969-01-01

    Reduction of retardation by diode-resistor networks of the current-decay time of a punch magnet by connection of a Zener diode in series with the damping network increases the reliability of data on paper tape.

  19. Star Catalogs on Punched Cards and Magnetic Tape

    NASA Technical Reports Server (NTRS)

    Berbert, J. H.

    1961-01-01

    In connection with the calibration of the Minitrack satellite tracking stations, the Goddard Space Flight Center has had the contents of a number of star catalogs put on punched cards and magnetic tape. This report discusses the plate data reduction procedures, briefly describes the information on the punched cards and magnetic tape, and calls attention to other applications of the card and tape star catalogs. The Goddard Space Flight Center has offered to prepare duplicate catalogs for qualified organizations.

  20. Stress relaxation by dislocation punching to radial direction from a long fiber in a composite

    SciTech Connect

    Shibata, Shoichi; Mori, T.; Taya, Minoru Washington University, Seattla )

    1992-02-01

    Radial dislocation punching, a relaxation process in a metal matrix composite, is investigated in the context of Eshelby's inclusion theory. The distribution of plastic strain after punching, the superposition of eigenstrains, the elastic state after punching, dissipation energy for punching, and punching distance are determined. By using the equivalent inclusion method, the analysis can be extended to the case where the elastic constants of an inclusion are different from those of the matrix. 14 refs.

  1. Diagnosis of cutaneous leishmaniasis: why punch when you can scrape?

    PubMed

    Saab, Mario; El Hage, Hussein; Charafeddine, Khalil; Habib, Robert H; Khalifeh, Ibrahim

    2015-03-01

    Cutaneous leishmaniasis (CL) has been introduced to the Leishmania under-endemic Lebanese population in an uncontrolled manner as a result of recent large-scale displacement of refugees from endemic Syria. Accordingly, a quick and reliable method to diagnose CL is essential. Matched punch biopsies and air-dried scrapings on 72 patients were obtained. Scrapings were collected in two forms: thick drop (N = 33) or thin smear (N = 39). Clinical information was recorded. Sections of punch biopsies and scrapings were stained and examined microscopically. Polymerase chain reaction (PCR) was performed on both scraping forms and biopsies. The diagnostic sensitivity of the tests performed revealed that microscopy in conjunction with PCR on punch biopsies was the most sensitive test (93%) overall. However, taken individually, microscopy and PCR yielded the highest sensitivities when performed on drop scrapings (63% and 85%, respectively), and not smear scrapings (38% and 56%, respectively) as compared with the punch biopsies (44% and 83%, respectively). Microscopic concordance for punch biopsies and drop scrapings was present in 25 of 33 cases. Concordance was predicted only by the high/low parasitic index (PI: 3.1 ± 1.7 and 0.4 ± 0.5, respectively; P < 0.05). Herein, we optimized a novel rapid method for reliable diagnosis of CL based on drop scrapings with good agreement with the gold standard punch biopsy technique. PMID:25561563

  2. Four energy levels device for skin punching

    NASA Astrophysics Data System (ADS)

    Savastru, D.; Ristici, Esofina; Mustata, Marina; Miclos, S.; Rusu, M. I.; Radu, C.; Savu, V.

    2007-03-01

    Generally, the beam distribution in the tissue in interaction with a pulsed laser is defined by optical properties (effective scattering and absorption coefficient). In 2900 nm range, the effective scattering coefficient is much smaller than the absorption coefficient. An Er:YAG skin puncher is presented. Thermal action of a laser beam can be described as one of three types: hyperthermia, coagulation and volatilization, depending on the degree and the duration of tissue heating. We are interested in the volatilization process that means a loss of material. The various constituents of the tissue disappear in smoke at above 100 0C in a relatively short time of around one tenth of a second. At the edges of the volatilization zone there is a region of coagulation necrosis. In presented case of an Er:YAG laser operating in a free generation mode, the mechanical effects can result from explosive vaporization. When the exposure time of the laser is lower than the characteristic time of the thermal diffusion in the tissue, it produces a thermal containment with an accumulation of heat without diffusion and an explosive vaporization of the target. The Er:YAG laser device has the pulse length of about 160 microseconds and four emitted energy levels. This device is used to punch the skin for blood sampling for different kinds of analysis. The front panel of the device has four keys to select the desired energy according to the skin type.

  3. The shear wave velocity structure of the heterogeneous alluvial plain of Beirut (Lebanon): combined analysis of geophysical and geotechnical data

    NASA Astrophysics Data System (ADS)

    Salloum, Nancy; Jongmans, Denis; Cornou, Cécile; Youssef Abdel Massih, Dalia; Hage Chehade, Fadi; Voisin, Christophe; Mariscal, Armand

    2014-11-01

    A geotechnical and geophysical campaign was performed at sites located in the alluvial plain of the river of Beirut (Lebanon), which is characterized by a significant lateral and vertical geological variability, along with anthropogenic disturbances in the first metres. The method combination has allowed detecting a shallow conductive low velocity layer of varying depth and thickness, corresponding to a soft clay layer embedded in coarser formations. This layer was found to exert strong control on the experimental dispersion curves (estimated from both active and passive experiments) characterized by a continuous mode superposition at high frequency, associated with an increase in phase velocity. Vs profiles in boreholes turned out to be of prime importance for adequately defining the parametrization before inversion and for ensuring the reliability of the inversion dispersive estimates at low frequency. A major output of this study is also to show that this low velocity layer, along with the strong shear velocity contrast at its bottom, significantly contributes to the site seismic response, and could make it difficult to use the measured H/V peak frequency as a proxy for the soil thickness over bedrock.

  4. Small punch testing for irradiation embrittlement. Final report

    SciTech Connect

    Foulds, J.R.

    1995-08-01

    Fracture mechanics analyses are used to evaluate nuclear reactor vessel integrity. These analyses require knowledge of a range of vessel material mechanical properties, particularly fracture properties. Estimation of vessel material fracture properties is currently made indirectly via correlations between embrittlement and vessel steel chemistry and neutron fluence, and by standard Charpy testing (for transition temperature or RT{sub NDT}) of surveillance material. The small punch test approach is a miniature specimen mechanical test which, based on accumulated experience with fossil plant steels, shows significant application potential for in-service nuclear reactor vessel irradiation embrittlement evaluation. The small punch test specimen is small enough to potentially overcome the surveillance material availability problem (30 small punch test specimens can be easily removed from a single standard half-Charpy bar) and even permit a direct vessel material interrogation by non-disruptive removal of miniature samples from the vessel. An immediate, near-term benefit of the small punch test approach will be the conservation of surveillance material. The results of preliminary feasibility testing on a heat of reactor vessel steel weld metal in the unirradiated, irradiated, and irradiated + annealed conditions show that the small punch test transition temperature correlates with the standard Charpy transition temperature. In addition, application of the small punch test-based fracture toughness (K{sub Ic}, J{sub Ic}) estimation method developed on a previous EPRI project (RP2426-38) produced toughness estimates for the irradiated steel within the {+-}25% accuracy range demonstrated on RP2426-38. The results show that the small punch test can be a viable means of evaluating irradiation embrittlement of reactor vessel steels. Recommendations are provided for further developing the test method for this application.

  5. Stress response of bovine artery and rat brain tissue due to combined translational shear and fixed unconfined compression

    NASA Astrophysics Data System (ADS)

    Leahy, Lauren

    During trauma resulting from impacts and blast waves, sinusoidal waves permeate the brain and cranial arterial tissue, both non-homogeneous biological tissues with high fluid contents. The experimental shear stress response to sinusoidal translational shear deformation at 1 Hz and 25% strain amplitude and either 0% or 33% compression is compared for rat brain tissue and bovine aortic tissue. Both tissues exhibit Mullins effect in shear. Harmonic wavelet decomposition, a novel application to the mechanical response of these tissues, shows significant 1 Hz and 3 Hz components. The 3 Hz component magnitude in brain tissue, which is much larger than in aortic tissue, may correlate to interstitial fluid induced drag forces that decrease on subsequent cycles perhaps because of damage resulting in easier fluid movement. The fluid may cause the quasiperiodic, viscoelastic behavior of brain tissue. The mechanical response differences under impact may cause shear damage between arterial and brain connections.

  6. Variation of fracture mode in micro-scale laser shock punching

    NASA Astrophysics Data System (ADS)

    Zheng, Chao; Ji, Zhong; Song, Libin; Fu, Jie; Zhu, Yunhu; Zhang, Jianhua

    2015-09-01

    Micro-scale laser shock punching is a high strain rate micro-forming method which uses the high-amplitude shock wave pressure induced by pulsed laser irradiation. The response of brass and pure titanium foils under the different ratio of laser beam diameter (d) to die hole diameter (D) in micro-scale laser shock punching was investigated experimentally and numerically. The typical fracture surface morphologies were observed using scanning electron microscope. Numerical simulations were conducted to predict the stress state of the workpiece before and after fracture. The influence of the ratio d/D on dynamic deformation and fracture of metal foils was characterized. The results demonstrate that both the crack locations and fracture surface morphologies of metal foils are strongly related to the ratio d/D. The fracture mode varies from a shear fracture mode to a mixed fracture mode, then to a tensile fracture mode as the ratio decreases. The stress state under the different ratio is discussed in detail and believed to be responsible for the variation.

  7. 22. NORTHEAST TO GENERAL VIEW OF CIRCA 1875 POWER SHEAR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. NORTHEAST TO GENERAL VIEW OF CIRCA 1875 POWER SHEAR, PUNCH, AND RIVETING MACHINE, SHOWING FLOOR SECTION RAISED TO EXPOSE OPERATOR'S 'PIT' AND SHOWING SHOP-MADE WROUGHT IRON BRACE REPAIR TO CRACKED TOP OF MACHINE. IN LEFT FOREGROUND IS BUFFALO FORGE CO. HAND SHEAR FOR ANGLE STEEL. IN BACKGROUND IN NORTHEAST CORNER OF FACTORY INTERIOR IS BLACKSMITH SHOP AREA WITH HOOD OVER FORGE. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  8. Low-velocity perforation of punch-impact-loaded metal plates

    SciTech Connect

    Wen, H.M.; Jones, N.

    1996-05-01

    The deformation and failure of structures when loaded statically or dynamically is important for safety calculations of various structural systems in the nuclear engineering, vehicle crash-worthiness, offshore engineering, naval architecture, and defense industries. In particular, the deformation and perforation behavior of plates is important for the design of containment and protective structures against projectiles or dropped objects or impact by fragments generated during an industrial explosion. Here, an approximate quasi-static theoretical analysis is presented for the behavior of punch-impact-loaded metal plates. Based on the principle of virtual work, load-deflection relationships are first obtained and then used to predict the energy-absorbing capabilities of plates subjected to low-velocity impacts that cause perforation. It is demonstrated that the theoretical predictions are in good agreement with experimental observations on fully clamped steel plates when material strain rate sensitivity is taken into consideration and provided that perforation does not occur by adiabatic shear plugging.

  9. Punch-through characteristics of FOXFET biased detectors

    SciTech Connect

    Bacchetta, N.; Da Ros, R.; Giraldo, A.; Gotra, Yu. ); Bisello, D.; Verzellesi, G. Univ. di Padova ); Paccagnella, A. Univ. di Cagliari . Istituto di Elettrotecnica)

    1994-08-01

    The main punch-through characteristics have been studied on Field OXide FETs (FOXFETs) used for microstrip biasing in Si detectors. The voltage-current DC curves have been studied on devices with different channel width/length ratios, fabricated on Si substrates with different doping levels. The punch-through threshold voltage depends on the positive charge in the gate oxide, device layout and temperature. The relation between punch-through current and dynamic resistance is insensitive to charge accumulation in the gate oxide induced by irradiation and to different Si donor doping levels. Dynamic resistance however varies as the doping changes from n- to p-type, and it also depends on the Si bulk damage induced by neutron irradiation. The AC impedance will reproduce the DC dynamic resistance, but show also large effects due to parasitic capacitance, which dominates the FOXFET response at high frequency and can affect the detector performance.

  10. Nanoindentation of soft solids by a flat punch

    NASA Astrophysics Data System (ADS)

    Wang, G. F.; Niu, X. R.

    2015-08-01

    Measuring the surface tension and elastic modulus of soft materials and biological tissues under different physiological and pathological conditions is of significance for understanding various phenomena associated with deformation. In this paper, the nanoindentation of a circular flat punch on a soft solid is analyzed with the influence of surface tension. By solving the corresponding singular integral equation, the relation between load and indent depth is obtained. When the radius of the flat punch shrinks to the same order as the ratio of surface tension to elastic modulus, surface tension significantly affects the indentation load-depth relation, which provides a facile method to measure surface tension in soft solids and biological tissues.

  11. Analysis of direct punch velocity in professional defence

    NASA Astrophysics Data System (ADS)

    Lapkova, Dora; Adamek, Milan

    2016-06-01

    This paper is focused on analysis of a direct punch. Nowadays, professional defence is basic part of effective protection of people and property. There are many striking techniques and the goal of this research was to analyze the direct punch. The analysis is aimed to measure the velocity with help of high speed camera Olympus i-Speed 2 and then find the dependences of this velocity on input parameters. For data analysis two pieces of software were used - i-Speed Control Software and MINITAB. 111 participants took part in this experiment. The results are presented in this paper - especially dependence of mean velocity on time and difference in velocity between genders.

  12. 18. SOUTHWEST TO CIRCA 1900 MICHIGAN MACHINERY MFG. CO. PUNCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. SOUTHWEST TO CIRCA 1900 MICHIGAN MACHINERY MFG. CO. PUNCH PRESS, CIRCA 1910 'THE RACINE' RECIPROCATING HACK SAW, AND CIRCA 1900 SNAG GRINDER NEAR CENTER OF FACTORY BUILDING. AT THE RIGHT ARE THREE WHEELED WORK STATIONS. THE LINE SHAFT WITH BELTS AND PULLEYS FOR OPERATING MACHINERY IS VISIBLE IN THE RIGHT BACKGROUND. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  13. 41 CFR 101-26.703 - Marginally punched continuous forms.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Marginally punched continuous forms. 101-26.703 Section 101-26.703 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 26-PROCUREMENT SOURCES AND PROGRAM...

  14. 41 CFR 101-26.703 - Marginally punched continuous forms.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Marginally punched continuous forms. 101-26.703 Section 101-26.703 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 26-PROCUREMENT SOURCES AND PROGRAM...

  15. 41 CFR 101-26.703 - Marginally punched continuous forms.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 2 2014-07-01 2012-07-01 true Marginally punched continuous forms. 101-26.703 Section 101-26.703 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 26-PROCUREMENT SOURCES AND PROGRAM...

  16. Configurational phases in elastic foams under lengthscale-free punching

    NASA Astrophysics Data System (ADS)

    Sabuwala, Tapan; Dai, Xiangyu; Gioia, Gustavo

    2016-08-01

    We carry out experiments with brick-like specimens of elastic open-cell (EOC) foams of three relative densities. Individual specimens may be "tall" (height = width = depth) or "short" (2 height = width = depth). We place each specimen on a supporting plate and use a lengthscale-free (wedge-shaped or conical) punch to apply forces downward along the specimen's height. Regardless of the type of specimen, the force-penetration curves remain linear, for the wedge-shaped punch, or quadratic, for the conical punch, up to a sizable penetration commensurate with the smallest lengthscale of the specimen. After that there is an abrupt, all-but-discontinuous change in stiffness: if the specimen is tall, the stiffness drops; if the specimen is short, the stiffness shoots up. To analyze these curious experimental results, we posit that EOC foams can be found in either of two configurational phases, here termed the low-strain phase and the high-strain phase, which share a two-dimensional interface (a surface of strain discontinuity). The analysis may be outlined as follows. In the first part of an experiment, there obtains a "similarity regime" in which the penetration of the punch and the radius of the interface are the only prevailing lengthscales (because the punch is lengthscale free). In this case, it is possible to show that the force-penetration curve must be linear, or quadratic, depending on whether the punch be wedge-shaped or conical, respectively. This prediction of the analysis is consistent with the experiments. In time, the similarity regime breaks down when the interface reaches one of the specimen's boundaries distal to the tip of the punch. If the specimen is tall, the soft, stress-free lateral boundary is reached first, and the stiffness must drop; if the specimen is short, the hard boundary in contact with the supporting plate is reached first, and the stiffness must shoot up. These predictions too are consistent with the experiments. To provide direct

  17. Buckling loads of stiffened panels subjected to combined longitudinal compression and shear: Results obtained with PASCO, EAL, and STAGS computer programs

    NASA Technical Reports Server (NTRS)

    Stroud, W. J.; Greene, W. H.; Anderson, M. S.

    1984-01-01

    Buckling analyses used in PASCO are summarized with emphasis placed on the shear buckling analyses. The PASCO buckling analyses include the basic VIPASA analysis, which is essentially exact for longitudinal and transverse loads, and a smeared stiffener solution, which treats a stiffened panel as an orthotropic plate. Buckling results are then presented for seven stiffened panels loaded by combinations of longitudinal compression and shear. The buckling results were obtained with the PASCO, EAL, and STAGS computer programs. The EAL and STAGS solutions were obtained with a fine finite element mesh and are very accurate. These finite element solutions together with the PASCO results for pure longitudinal compression provide benchmark calculations to evaluate other analysis procedures.

  18. Communication: Slow supramolecular mode in amine and thiol derivatives of 2-ethyl-1-hexanol revealed by combined dielectric and shear-mechanical studies

    NASA Astrophysics Data System (ADS)

    Adrjanowicz, K.; Jakobsen, B.; Hecksher, T.; Kaminski, K.; Dulski, M.; Paluch, M.; Niss, K.

    2015-11-01

    In this paper, we present results of dielectric and shear-mechanical studies for amine (2-ethyl-1-hexylamine) and thiol (2-ethyl-1-hexanethiol) derivatives of the monohydroxy alcohol, 2-ethyl-1-hexanol. The amine and thiol can form hydrogen bonds weaker in strength than those of the alcohol. The combination of dielectric and shear-mechanical data enables us to reveal the presence of a relaxation mode slower than the α-relaxation. This mode is analogous to the Debye mode seen in monohydroxy alcohols and demonstrates that supramolecular structures are present for systems with lower hydrogen bonding strength. We report some key features accompanying the decrease in the strength of the hydrogen bonding interactions on the relaxation dynamics close to the glass-transition. This includes changes (i) in the amplitude of the Debye and α-relaxations and (ii) the separation between primary and secondary modes.

  19. Separate and combined effects of static stability and shear variation on the baroclinic instability of a two-layer current

    NASA Technical Reports Server (NTRS)

    Hyun, J. M.

    1981-01-01

    Quasi-geostrophic disturbance instability characteristics are studied in light of a linearized, two-layer Eady model in which both the static stability and the zonal current shear are uniform but different in each layer. It is shown that the qualitative character of the instability is determined by the sign of the basic-state potential vorticity gradient at the layer interface, and that there is a qualitative similarity between the effects of Richardson number variations due to changes in static stability and those due to changes in shear. The two-layer model is also used to construct an analog of the Williams (1974) continuous model of generalized Eady waves, the basic state in that case having zero potential vorticity gradient in the interior. The model results are in good agreement with the earlier Williams findings.

  20. Post-buckling of geometrically imperfect shear-deformable flat panels under combined thermal and compressive edge loadings

    NASA Technical Reports Server (NTRS)

    Librescu, L.; Souza, M. A.

    1993-01-01

    The static post-buckling of simply-supported flat panels exposed to a stationary nonuniform temperature field and subjected to a system of subcritical in-plane compressive edge loads is investigated. The study is performed within a refined theory of composite laminated plates incorporating the effect of transverse shear and the geometric nonlinearities. The influence played by a number of effects, among them transverse shear deformation, initial geometric imperfections, the character of the in-plane boundary conditions and thickness ratio are studied and a series of conclusions are outlined. The influence played by the complete temperature field (i.e., the uniform through thickness and thickness-wise gradient) as compared to the one induced by only the uniform one, is discussed and the peculiarities of the resulting post-buckling behaviors are enlightened.

  1. Small punch testing for fracture toughness measurement. Final report

    SciTech Connect

    Foulds, J.R.; Woytowitz, P.J.; Parnell, T.K.

    1995-06-01

    The fracture toughness of the material of an operating power plant structural component affects the flaw tolerance of the component. A lower toughness implies a lower flaw tolerance, and generally results in an increased concern for component integrity and higher operation and maintenance costs. Often, the material fracture toughness is unknown because it was never specified or measured, or because service conditions have resulted in its degradation to an unknown extent. Examples of in- service degradation include temper embrittlement of steam turbine rotor low alloy steels exposed to elevated temperatures and neutron irradiation embrittlement of nuclear reactor pressure vessel steels. Conventional test methods for measuring toughness require the removal of large material samples from the in-service component, which is generally impractical. However, the recent development of miniature sample removal systems and the small punch test technique (which utilizes non-standard, miniature specimens of 0.5 mm or 0.020 in. thickness) now provides a convenient, practical, and virtually nondestructive means of evaluating the material of an in-service component for toughness and related mechanical properties. The small punch test method follows an approach that is based on the continuum material toughness concept wherein the criterion for fracture is defined and measured via the continuum stress-strain deformation properties of the material. The procedure specifically involves computing the {open_quotes}local{close_quotes} strain energy density accumulated at the location and time of crack initiation in the small punch test specimen using large-strain finite element analysis. Since the procedure also includes estimation of the material uniaxial tensile stress-strain behavior from the small punch load-displacement curve, both the fracture toughness and the uniaxial tensile behavior are determined from a single small punch test.

  2. Precision Small Angle Bending of Sheet Metals Using Shear Deformation

    NASA Astrophysics Data System (ADS)

    Hirota, Kenji; Mori, Yorifumi

    This paper deals with a new method to bend sheet metals at a small angle precisely, in which a sheet metal is slightly bent by shear deformation at negative punch-die clearance. Deformation behavior and key factors affecting on the bend angle were studied in detail with pure aluminum sheets. It was proved that the bend angle was changed in proportion to both punch penetration and negative punch-die clearance within a certain range. The same was true for high-strength steel and phosphor bronze, which are difficult to bend precisely by conventional methods due to large springback after unloading. By using this relationship as a control law, four kinds of sheet metals were precisely bent within a few degrees. This method was applied to correct the angular errors in U-bend products of high-strength steel and to bend leaf springs of phosphor bronze at an arbitrary small angle.

  3. Undrained shear strength of partially saturated combined coal refuse. First annual report: Strength and consolidation characteristics of coal refuse for design and construction of disposal facilities

    SciTech Connect

    Huang, Y.H.; Li, J.

    1986-09-01

    This report summarizes the results of a study on the undrained shear strength of partially saturated combined refuse. The study is part of a research project entitled 'Strength and Consolidation Characteristics of Coal Refuse for Design and Construction of Disposal Facilities supported by the Office of Surface Mining, Department of the Interior. Information presented in the report will be used for the design and construction of disposal facilities. Coal refuse, the waste product from coal washing, is separated in the coal preparation plant into two fractions (coarse and fine). The fine refuse, in the form of either a slurry or a filter cake, is unstable and difficult to handle.

  4. Hemodynamic Performance of a New Punched Stent Strut: A Numerical Study.

    PubMed

    Xue, Yan; Liu, Xiao; Sun, Anqiang; Zhang, Peng; Fan, Yubo; Deng, Xiaoyan

    2016-07-01

    Local flow disturbance by arterial stent struts has been shown to play an important role in stent thrombosis. To reduce the local flow disturbance near a stent strut, we proposed a new concept of stent design with small holes in the stent struts. The present study evaluated the new design numerically by comparing it with the traditional stent in terms of local hemodynamic parameters such as flow velocity, flow recirculation area, time-averaged wall shear stress (TAWSS), oscillating shear index (OSI), and relative residence time (RRT). The results demonstrated that when compared with the traditional strut, the new design could significantly enhance flow velocity and reduce the flow recirculation zone in the vicinity of the strut. Moreover, the new design would significantly elevate TAWSS and remarkably reduce OSI and RRT along the host arterial wall. In conclusion, the new design of stent struts with punched holes is advantageous over the traditional one in the aspect of improving local hemodynamics, which may reduce thrombosis formation and promote re-endothelialization after stenting. PMID:26581476

  5. Manufacture of superconducting niobium cavity parts by hydropercussion punching

    NASA Astrophysics Data System (ADS)

    Azaryan, N. S.; Shirkov, G. D.; Zhurauski, A. Yu.; Petrakovski, V. S.; Batouritski, M. A.

    2016-03-01

    A complete cycle of manufacturing all parts of superconducting niobium cavities which comprise two half-cells, two drift tubes, and two flanges each has been developed. The cavity half-cells are manufactured by hydropercussion punching, which has a number of advantages over the instrumental stamping technique. For the first time, the diagram of formability of ultrapure niobium has been experimentally obtained for hydropercussion punching and the key parameters of the process have been determined that ensure complete deep-drawing of workpieces, viz., the value of the limit drawing ratio of ultrapure niobium that is 1.92 at a specific impact energy of 0.42 MJ/m2. The deviations of the half-cell dimensions from the rated values do not exceed 0.1 mm. Production tools required for all manufacturing steps have been created. The parameters of machining of the niobium cavity parts prior to welding have been experimentally established.

  6. Qualification of P91 welds through Small Punch creep testing

    NASA Astrophysics Data System (ADS)

    Blagoeva, D.; Li, Y. Z.; Hurst, R. C.

    2011-02-01

    The deployment of the martensitic alloy P91 in future nuclear plant components operating in the creep regime depends very much on the performance of joints, found occasionally susceptible to failure in fossil fuel fired plant A completely novel approach is proposed to assess the integrity of P91 weldments which relies on the determination of the creep properties of the different zones of the weldment on a micro-scale based on the Small Punch (SP) testing methodology. Results are presented from the Small Punch creep tests carried out exactly following a CEN Code of Practice for the various constituent zones of the weldment and the potential weaknesses are identified within the heat affected zone. In addition, the SP test is applied to determine the fracture properties of the weld compared to the parent metal, showing the expected shift related to the test method in the ductile brittle transition temperature and the inferior performance of the weld metal.

  7. Paper recycling: ERI rolls with the punches

    SciTech Connect

    Lieb, K.

    1993-10-01

    At a time when many independent recycling companies are struggling to survive, Environmental Recycling, Inc. (ERI) maintains more than 600 accounts and is making a profit. ERI, an intermediate processor in Alexandria, Virginia combines elements of hauling and dealing. Paper is collected from mail houses, municipality contracts, federal contracts, and routine pick-ups and drop-offs in several municipalities around Virginia, Washington D.C., and Maryland. Creative marketing allows the company to stay afloat, and even thrive.

  8. Variable temperature thin film indentation with a flat punch.

    PubMed

    Cross, Graham L W; O'Connell, Barry S; Pethica, John B; Rowland, Harry; King, William P

    2008-01-01

    We present modifications to conventional nanoindentation that realize variable temperature, flat punch indentation of ultrathin films. The technique provides generation of large strain, thin film extrusion of precise geometries that idealize the essential flows of nanoimprint lithography, and approximate constant area squeeze flow rheometry performed on thin, macroscopic soft matter samples. Punch radii as small as 185 nm have been realized in ten-to-one confinement ratio testing of 36 nm thick polymer films controllably squeezed in the melt state to a gap width of a few nanometers. Self-consistent, compressive stress versus strain measurements of a wide variety of mechanical testing conditions are provided by using a single die-sample system with temperatures ranging from 20 to 125 degrees C and loading rates spanning two decades. Low roughness, well aligned flat punch dies with large contact areas provide precise detection of soft surfaces with standard nanoindenter stiffness sensitivity. Independent heating and thermometry with heaters and thermocouples attached to the die and sample allow introduction of a novel directional heat flux measurement method to ensure isothermal contact conditions. This is a crucial requirement for interpreting the mechanical response in temperature sensitive soft matter systems. Instrumented imprint is a new nanomechanics material testing platform that enables measurements of polymer and soft matter properties during large strains in confined, thin film geometries and extends materials testing capabilities of nanoindentation into low modulus, low strength glassy, and viscoelastic materials. PMID:18248047

  9. Complementary Post Transcriptional Regulatory Information is Detected by PUNCH-P and Ribosome Profiling.

    PubMed

    Zur, Hadas; Aviner, Ranen; Tuller, Tamir

    2016-01-01

    Two novel approaches were recently suggested for genome-wide identification of protein aspects synthesized at a given time. Ribo-Seq is based on sequencing all the ribosome protected mRNA fragments in a cell, while PUNCH-P is based on mass-spectrometric analysis of only newly synthesized proteins. Here we describe the first Ribo-Seq/PUNCH-P comparison via the analysis of mammalian cells during the cell-cycle for detecting relevant differentially expressed genes between G1 and M phase. Our analyses suggest that the two approaches significantly overlap with each other. However, we demonstrate that there are biologically meaningful proteins/genes that can be detected to be post-transcriptionally regulated during the mammalian cell cycle only by each of the approaches, or their consolidation. Such gene sets are enriched with proteins known to be related to intra-cellular signalling pathways such as central cell cycle processes, central gene expression regulation processes, processes related to chromosome segregation, DNA damage, and replication, that are post-transcriptionally regulated during the mammalian cell cycle. Moreover, we show that combining the approaches better predicts steady state changes in protein abundance. The results reported here support the conjecture that for gaining a full post-transcriptional regulation picture one should integrate the two approaches. PMID:26898226

  10. Complementary Post Transcriptional Regulatory Information is Detected by PUNCH-P and Ribosome Profiling

    PubMed Central

    Zur, Hadas; Aviner, Ranen; Tuller, Tamir

    2016-01-01

    Two novel approaches were recently suggested for genome-wide identification of protein aspects synthesized at a given time. Ribo-Seq is based on sequencing all the ribosome protected mRNA fragments in a cell, while PUNCH-P is based on mass-spectrometric analysis of only newly synthesized proteins. Here we describe the first Ribo-Seq/PUNCH-P comparison via the analysis of mammalian cells during the cell-cycle for detecting relevant differentially expressed genes between G1 and M phase. Our analyses suggest that the two approaches significantly overlap with each other. However, we demonstrate that there are biologically meaningful proteins/genes that can be detected to be post-transcriptionally regulated during the mammalian cell cycle only by each of the approaches, or their consolidation. Such gene sets are enriched with proteins known to be related to intra-cellular signalling pathways such as central cell cycle processes, central gene expression regulation processes, processes related to chromosome segregation, DNA damage, and replication, that are post-transcriptionally regulated during the mammalian cell cycle. Moreover, we show that combining the approaches better predicts steady state changes in protein abundance. The results reported here support the conjecture that for gaining a full post-transcriptional regulation picture one should integrate the two approaches. PMID:26898226

  11. Treatment of a Refractory Skin Ulcer Using Punch Graft and Autologous Platelet-Rich Plasma

    PubMed Central

    Carducci, Mauro; Bozzetti, Marcella; Spezia, Marco; Ripamonti, Giorgio; Saglietti, Giuseppe

    2016-01-01

    Background. Chronic ulceration of the lower legs is a relatively common condition amongst adults: one that causes pain and social distress and results in considerable healthcare and personal costs. The technique of punch grafting offers an alternative approach to the treatment of ulcers of the lower limbs. Objective. Combining platelet-rich plasma and skin graft enhances the efficacy of treating chronic diabetic wounds by enhancing healing rate and decreasing recurrence rate. Platelet-rich plasma could, by stimulating dermal regeneration, increase the take rate after skin grafting or speed up reepithelialization. Methods and Materials. The ulcer was prepared by removing fibrin with a curette and the edges of the ulcer were freshened. The platelet-rich plasma has been infiltrated on the bottom and edges of the ulcer. The punch grafts were placed in 5 mm holes arranged. The ulcer was medicated with hydrogel and a pressure dressing was removed after 8 days. Results. After a few days the patient did not report more pain. Granulation tissue appeared quickly between implants. Most of the grafts were viable in 2-3 weeks. The grafts gradually came together to close the ulcer and were completed in four months. PMID:26989524

  12. Big Punches Come in Nanosizes for Chemoprevention

    PubMed Central

    Sharma, Dipali; Sukumar, Saraswati

    2014-01-01

    Literature to support the chemopreventive potential of several bioactive molecules has been prolific and convincing, but the clinical development of these agents has been slow. Major hurdles for development of bioactive chemoprevention approaches include low potency, lack of reliable formulations with high bioavailability that are suitable for oral administration, and relevant preclinical primary prevention models that use meaningful doses that can be translated to humans. The paper presented in this issue (Grandhi and colleagues) is an important step forward in this direction. It shows the efficacy of an oral, low dose, solid-lipid nanoparticles encapsulated curcumin and aspirin combined with free sulforaphane for long-term chemoprevention of pancreatic cancer in a carcinogen-induced hamster model. Reproducing this benefit in multiple cancer models, accompanied by development of intermediate markers of response will allow rapid translation of these findings. It will constitute the first successful multipronged attack at key pathways known to initiate and promote carcinogenesis. PMID:24072677

  13. Photoelastic studies of three-dimensional stress field caused by a cylindrical punch

    SciTech Connect

    Chu, S.N.G.; Li, J.C.M.

    1980-06-01

    A stress-freezing technique is used to observe the stress distribution inside a cylindrical body produced by a coaxially loaded cylindrical punch. The flat end of the punch is pressed against the top surface of a vertical cylinder. After the stress is frozen in, a thin vertical diametric slice is prepared for photoelastic observation. The stress distribution is compared with theoretical results calculated for a semi-infinite body using the following two boundary conditions: uniform displacement of the punch and uniform pressure under the punch. The agreement is good at long distances (three times the punch radius) with either boundary condition. At short distances, the observed stress distribution is in between but close to the uniform displacement boundary condition. These results support the use of mixed stress distributions under the punch in a previous finite-element calculation of impressing creep velocities.

  14. Micromechanical and in situ shear testing of Al–SiC nanolaminate composites in a transmission electron microscope (TEM)

    SciTech Connect

    Mayer, Carl; Li, Nan; Mara, Nathan Allan; Chawla, Nikhilesh

    2014-11-07

    Nanolaminate composites show promise as high strength and toughness materials. Still, due to the limited volume of these materials, micron scale mechanical testing methods must be used to determine the properties of these films. To this end, a novel approach combining a double notch shear testing geometry and compression with a flat punch in a nanoindenter was developed to determine the mechanical properties of these films under shear loading. To further elucidate the failure mechanisms under shear loading, in situ TEM experiments were performed using a double notch geometry cut into the TEM foil. Aluminum layer thicknesses of 50nm and 100nm were used to show the effect of constraint on the deformation. Higher shear strength was observed in the 50 nm sample (690±54 MPa) compared to the 100 nm sample (423±28.7 MPa). Additionally, failure occurred along the Al-SiC interface in the 50 nm sample as opposed to failure within the Al layer in the 100 nm sample.

  15. Micromechanical and in situ shear testing of Al–SiC nanolaminate composites in a transmission electron microscope (TEM)

    DOE PAGESBeta

    Mayer, Carl; Li, Nan; Mara, Nathan Allan; Chawla, Nikhilesh

    2014-11-07

    Nanolaminate composites show promise as high strength and toughness materials. Still, due to the limited volume of these materials, micron scale mechanical testing methods must be used to determine the properties of these films. To this end, a novel approach combining a double notch shear testing geometry and compression with a flat punch in a nanoindenter was developed to determine the mechanical properties of these films under shear loading. To further elucidate the failure mechanisms under shear loading, in situ TEM experiments were performed using a double notch geometry cut into the TEM foil. Aluminum layer thicknesses of 50nm andmore » 100nm were used to show the effect of constraint on the deformation. Higher shear strength was observed in the 50 nm sample (690±54 MPa) compared to the 100 nm sample (423±28.7 MPa). Additionally, failure occurred along the Al-SiC interface in the 50 nm sample as opposed to failure within the Al layer in the 100 nm sample.« less

  16. A New Sheet Metal Forming System Based on Incremental Punching

    NASA Astrophysics Data System (ADS)

    Luo, Yuanxin

    Stamping is one of the most commonly used manufacturing processes. Everyday, millions of parts are formed by this process. The conventional stamping is to form a part in one or several operations with a press machine and a set/sets of dies. It is very efficient but is not cost effective for small batch production parts and prototypes as the dies are expensive and time consuming to make. Recently, with the increasing demands for low-volume and customer-made products, a die-less forming method, Incremental Sheet Metal Forming (ISMF), has become one of the leading R&D topics in the industry. ISMF uses a small generic tool to apply a sequence of operations along the given path to deform the sheet incrementally. These small deformations accumulate to form the final shape of the part. As a result, different parts can be made by the same setup. Despite of some 30 years of research and development, however, ISMF technology is still premature for industrial applications due to the following reasons: The accuracy of the part is limited; the surface roughness is poor; and the productivity is low. This motivates the presented research. In this research, a new incremental forming system based on incremental punching is designed and built. The system consists of a 3-axes CNC platform, a high speed hydraulic cylinder with a hemispherical forming tool, and a PC-based CNC control system. The hydraulic system provides the forming force to deform the sheet metal with constant stokes, while the CNC system positions the part. When forming a part, the forming tool punches the sheet metal along the given contour of the part punch by punch; when one layer of the part is completed, the forming tool moves down to the next layer; and the process is finished till all layers are completed. The CNC control system works with standard NC code, and hence, is easy to use. In order to ensure the desirable performance of the machine, dynamic analysis of the machine is necessary. The analysis is

  17. Some Investigations of the General Instability of Stiffened Metal Cylinders VI : Stiffened Metal Cylinders Subjected to Combined Bending and Transverse Shear

    NASA Technical Reports Server (NTRS)

    1943-01-01

    This is the sixth of a series of reports covering an investigation of the general instability problem by the California Institute of Technology. The first five reports of this series cover investigations of the general instability problem under the loading conditions of pure bending and were prepared under the sponsorship of the Civil Aeronautics Administration. This report and the succeeding reports of this series cover the work done on other loading conditions under the sponsorship of the National Advisory Committee for Aeronautics. This report summarizes the work that has been carried on in the experimental investigation of the problem of general instability of stiffened metal cylinders subjected to combined bending and transverse shear at the C.I.T. This part of the investigation includes tests on 55 sheet-covered specimens.

  18. Punch valve development testing: Low and high velocity test results

    SciTech Connect

    Replogle, W.C.; Brandon, S.L.

    1996-09-01

    This is a report on the use of quasi-static tests to predict fundamental parameters for punch valve development. This report summarizes the results from low and high velocity tests performed with 0.63 and 0.38 cm diameter plungers, 5 cm long penetrating aluminium and composite targets. The low velocity tests, 0.025 m/s, were performed to understand the effects and interactions of plunger diameter plunger tip shape, target material, and target support on penetration energy and plunger functionality. High velocity tests, 75 m/s, were compared to low velocity results.

  19. Shear Lag in a Plywood Sheet-stringer Combination Used for the Chord Member of a Box Beam

    NASA Technical Reports Server (NTRS)

    Borsari, Palamede; Yu, Ai-Ting

    1948-01-01

    Theoretical and experimental investigations were made of the distribution of strains in a plywood sheet-stringer combination used as the chord member of a box beam acted upon by bending loads. The theoretical solution was obtained with the help of the principle of minimum potential energy and certain simplifying assumptions. Strain measurements were made on a build-up box beam by means of electrical-resistance strain gages connected with strain indicators. A very satisfactory agreement between the theoretical and experimental strains was obtained.

  20. Kinematics of syn- and post-exhumational shear zones at Lago di Cignana (Western Alps, Italy): constraints on the exhumation of Zermatt-Saas (ultra)high-pressure rocks and deformation along the Combin Fault and Dent Blanche Basal Thrust

    NASA Astrophysics Data System (ADS)

    Kirst, Frederik; Leiss, Bernd

    2016-03-01

    Kinematic analyses of shear zones at Lago di Cignana in the Italian Western Alps were used to constrain the structural evolution of units from the Piemont-Ligurian oceanic realm (Zermatt-Saas and Combin zones) and the Adriatic continental margin (Dent Blanche nappe) during Palaeogene syn- and post-exhumational deformation. Exhumation of Zermatt-Saas (U)HP rocks to approximately lower crustal levels at ca. 39 Ma occurred during normal-sense top-(S)E shearing under epidote-amphibolite-facies conditions. Juxtaposition with the overlying Combin zone along the Combin Fault at mid-crustal levels occurred during greenschist-facies normal-sense top-SE shearing at ca. 38 Ma. The scarcity of top-SE kinematic indicators in the hanging wall of the Combin Fault probably resulted from strain localization along the uppermost Zermatt-Saas zone and obliteration by subsequent deformation. A phase of dominant pure shear deformation around 35 Ma affected units in the direct footwall and hanging wall of the Combin Fault. It is interpreted to reflect NW-SE crustal elongation during updoming of the nappe stack as a result of underthrusting of European continental margin units and the onset of continental collision. This phase was partly accompanied and followed by ductile bulk top-NW shearing, especially at higher structural levels, which transitioned into semi-ductile to brittle normal-sense top-NW deformation due to Vanzone phase folding from ca. 32 Ma onwards. Our structural observations suggest that syn-exhumational deformation is partly preserved within units and shear zones exposed at Lago di Cignana but also that the Combin Fault and Dent Blanche Basal Thrust experienced significant post-exhumational deformation reworking and overprinting earlier structures.

  1. Hamate body and capitate fracture in punch injury.

    PubMed

    Goliver, Jacob A; Adamow, Joshua S; Goliver, Jake

    2014-10-01

    Hamate fractures represent only 2% to 4% of all carpal bone fractures because they require a large degree of force to the hand or wrist. This is a case report of a patient with hamate and capitate fractures after a punch injury. It details the minute change seen in routine 3-view radiographic imagery and indications for computed tomography. A 29-year-old African American man with professional boxing training presented to the emergency department with pain and swelling in the hand and wrist after striking a refrigerator with his right hand. Enough force generated along the axial plane of the fourth and fifth metacarpals either from punching or from falling with a clenched fist is capable of fracturing both the hamate and capitate bones. Three-view radiographs may not visualize the fracture, so computed tomography should be ordered to better visualize any pathology. The risks to not detecting a hamate body fracture are nonunion of the bone, posttraumatic arthritis, decreased grip strength, and decreased range of motion of the hand. Because of rarity, there is no criterion standard therapy, but the general approach is open reduction and internal fixation using Kirschner wires and wrist immobilization for a minimum of 8 weeks. A high degree of clinical suspicion on examination is required for the proper approach to confirm a hamate fracture. PMID:24792935

  2. Combined plate motion and density driven flow in the asthenosphere beneath Saudi Arabia: Evidence from shear-wave splitting and seismic anisotropy

    SciTech Connect

    Hansen, S; Schwartz, S

    2006-02-08

    A comprehensive study of mantle anisotropy along the Red Sea and across Saudi Arabia was performed by analyzing shear-wave splitting recorded by stations from three different seismic networks: the largest, most widely distributed array of stations examined across Saudi Arabia to date. Stations near the Gulf of Aqaba display fast orientations that are aligned parallel to the Dead Sea Transform Fault, most likely related to the strike-slip motion between Africa and Arabia. However, most of our observations across Saudi Arabia are statistically the same, showing a consistent pattern of north-south oriented fast directions with delay times averaging about 1.4 s. Fossilized anisotropy related to the Proterozoic assembly of the Arabian Shield may contribute to the pattern but is not sufficient to fully explain the observations. We feel that the uniform anisotropic signature across Saudi Arabia is best explained by a combination of plate and density driven flow in the asthenosphere. By combining the northeast oriented flow associated with absolute plate motion with the northwest oriented flow associated with the channelized Afar plume along the Red Sea, we obtain a north-south oriented resultant that matches our splitting observations and supports models of active rifting processes. This explains why the north-south orientation of the fast polarization direction is so pervasive across the vast Arabian Plate.

  3. Identifying the unique ground motion signatures of supershear earthquakes - The one-two punch effect on high-rise buildings

    NASA Astrophysics Data System (ADS)

    Rosakis, A.; Mello, M.; Bhat, H.; Krishnan, S.; Kanamori, H.

    2011-12-01

    Directly studying earthquakes presents a host of insurmountable difficulties, the least of which is our inability to trigger earthquakes of various magnitudes at will and the lack of means of scrutinizing the behavior at depth while the quake propagates. We have developed techniques to produce miniature (or surrogate) laboratory earthquakes and follow their progress with high-speed imaging tools. Our laboratory quakes mimic actual ones, and have allowed us to demonstrate the existence of ruptures of super-shear or intersonic rupture speeds. The propagating fronts of such supershear ruptures feature a Mach-cone of shear shock waves similar to that of supersonic aircraft. For earthquake ruptures transitioning from sub-Rayleigh to supershear rupture speeds, this unusual shear Mach cone feature is also followed by a trailing Rayleigh disturbance which is all that remains of the old sub-Rayleigh rupture after transition is complete. Each propagating disturbance contributes to the unique ground motion signature in the near field. We refer to this as a one-two punch scenario. In particular, ground motion associated with passage of the shear Mach features a dominant fault-parallel velocity component while ground motion from the trailing Rayleigh field is characterized by a dominant fault-normal velocity component (characteristic of common, sub-shear earthquake ruptures). Appropriate scaling of the laboratory ground velocity measurements are used to shake 3-D numerical models of high-rise buildings (located in near fault locations) with hypothetical supershear and sub-Rayleigh earthquakes with unexpected implication to building safety and seismic hazard analysis.

  4. Demonstration of the self-magnetic-pinch diode as an X-ray source for flash core-punch radiography.

    SciTech Connect

    Cordova, Steve Ray; Rovang, Dean Curtis; Portillo, Salvador; Oliver, Bryan Velten; Bruner, Nichelle Lee; Ziska, Derek Raymond

    2007-10-01

    Minimization of the radiographic spot size and maximization of the radiation dose is a continuing long-range goal for development of electron beam driven X-ray radiography sources. In collaboration with members of the Atomic Weapons Establishment(AWE), Aldermaston UK, the Advanced Radiographic Technologies Dept. 1645 is conducting research on the development of X-ray sources for flash core-punch radiography. The Hydrodynamics Dept. at AWE has defined a near term radiographic source requirement for scaled core-punch experiments to be 250 rads{at}m with a 2.75 mm source spot-size. As part of this collaborative effort, Dept. 1645 is investigating the potential of the Self-Magnetic-Pinched (SMP) diode as a source for core-punch radiography. Recent experiments conducted on the RITS-6 accelerator [1,2] demonstrated the potential of the SMP diode by meeting and exceeding the near term radiographic requirements established by AWE. During the demonstration experiments, RITS-6 was configured with a low-impedance (40 {Omega}) Magnetically Insulated Transmission Line (MITL), which provided a 75-ns, 180-kA, 7.5-MeV forward going electrical pulse to the diode. The use of a low-impedance MITL enabled greater power coupling to the SMP diode and thus allowed for increased radiation output. In addition to reconfiguring the driver (accelerator), geometric changes to the diode were also performed which allowed for an increase in dose production without sacrificing the time integrated spot characteristics. The combination of changes to both the pulsed power driver and the diode significantly increased the source x-ray intensity.

  5. Frictionless contact of an elastic punch subject to the normal load and bending moment

    NASA Astrophysics Data System (ADS)

    Jiang, X.; Shao, G.; Zhu, L.

    2016-03-01

    A two-dimensional contact problem of a trapezium shaped punch pressed into a frictionless, elastically similar half-plane and subject sequentially to the normal load and bending moment is considered. The model of a tilted flat punch is used to evaluate the pressure distribution and the contact deformation within the contact zone. Comparisons of the results generated by the analytical technique to those computed by the finite element method demonstrate the high level of accuracy attained by both methods. The presented numerical results illustrate the effects of the normal load, bending moment, and internal angles of the punch geometry on the contact stresses.

  6. John Punch, Scotist Holy War, and the Irish Catholic Revolutionary Tradition in the Seventeenth Century.

    PubMed

    Campbell, Ian W

    2016-07-01

    During the 1640s, the Irish Franciscan theologian John Punch taught his theology students in Rome that war against Protestants was made just by their religion alone. Jesuits like Luis de Molina identified the holy war tradition in which Punch stood as a Scotist one, and insisted that the Scotists had confused the natural and supernatural spheres. Among Irishmen, Punch was unusual. The main Irish Catholic revolutionary tradition employed Jesuit and Thomist theory. They argued that the Stuarts had lost the right to rule Ireland for natural reasons, not supernatural ones; because the Stuarts were tyrants, not because they were Protestants. PMID:27477343

  7. High-throughput sequencing of forensic genetic samples using punches of FTA cards with buccal swabs.

    PubMed

    Kampmann, Marie-Louise; Buchard, Anders; Børsting, Claus; Morling, Niels

    2016-01-01

    Here, we demonstrate that punches from buccal swab samples preserved on FTA cards can be used for high-throughput DNA sequencing, also known as massively parallel sequencing (MPS). We typed 44 reference samples with the HID-Ion AmpliSeq Identity Panel using washed 1.2 mm punches from FTA cards with buccal swabs and compared the results with those obtained with DNA extracted using the EZ1 DNA Investigator Kit. Concordant profiles were obtained for all samples. Our protocol includes simple punch, wash, and PCR steps, reducing cost and hands-on time in the laboratory. Furthermore, it facilitates automation of DNA sequencing. PMID:27625209

  8. A Manual Retrieval System Using Computer Punch Cards for Qualitative Historical Research

    ERIC Educational Resources Information Center

    Feldman, Robert S.

    1973-01-01

    Detailed examples illustrate one of the possible applications for using the computer punch card for information retrieval in qualitative historical research, suggesting a time-saving method of organization for research data. (SM)

  9. Micro-punching process based on spallation delamination induced by laser driven-flyer

    NASA Astrophysics Data System (ADS)

    Di, Jianke; Zhou, Ming; Li, Jian; Li, Chen; Zhang, Wei; Amoako, George

    2012-01-01

    In this article, we proposed a micro-punching process for microstructure on films based on laser driven-flyer induced spallation delamination phenomenon at the interface between a film and its substrate. To validate such a micro-punching process, a series of experiments were carried out for fabrication of microstructures on Au films coated on K9 glass substrates and polyimide substrate. Results show that through such a punching process, the microstructure on Au films can be fabricated efficiently and the spatial resolution is able to reach micron level. Moreover, we found that this method was more suitable for films coated on soft substrates rather than that coated on brittle substrates due to the additional destruction of the brittle substrate. This micro-punching process has a wide range of potential application in microfluidic devices, biodevices and other MEMS devices.

  10. The JKR-type adhesive contact problems for power-law shaped axisymmetric punches

    NASA Astrophysics Data System (ADS)

    Borodich, Feodor M.; Galanov, Boris A.; Suarez-Alvarez, Maria M.

    2014-08-01

    The JKR (Johnson, Kendall, and Roberts) and Boussinesq-Kendall models describe adhesive frictionless contact between two isotropic elastic spheres, and between a flat-ended axisymmetric punch and an elastic half-space respectively. However, the shapes of contacting solids may be more general than spherical or flat ones. In addition, the derivation of the main formulae of these models is based on the assumption that the material points within the contact region can move along the punch surface without any friction. However, it is more natural to assume that a material point that came to contact with the punch sticks to its surface, i.e. to assume that the non-slipping boundary conditions are valid. It is shown that the frictionless JKR model may be generalized to arbitrary convex, blunt axisymmetric body, in particular to the case of the punch shape being described by monomial (power-law) punches of an arbitrary degree d≥1. The JKR and Boussinesq-Kendall models are particular cases of the problems for monomial punches, when the degree of the punch d is equal to two or it goes to infinity respectively. The generalized problems for monomial punches are studied under both frictionless and non-slipping (or no-slip) boundary conditions. It is shown that regardless of the boundary conditions, the solution to the problems is reduced to the same dimensionless relations among the actual force, displacements and contact radius. The explicit expressions are derived for the values of the pull-off force and for the corresponding critical contact radius. Connections of the results obtained for problems of nanoindentation in the case of the indenter shape near the tip has some deviation from its nominal shape and the shape function can be approximated by a monomial function of radius, are discussed.

  11. Performance Assessment of Hard Rock TBM and Rock Boreability Using Punch Penetration Test

    NASA Astrophysics Data System (ADS)

    Jeong, Ho-Young; Cho, Jung-Woo; Jeon, Seokwon; Rostami, Jamal

    2016-04-01

    Rock indentation tests are often called punch penetration tests and are known to be related to penetration rates of drilling equipment and hard rock tunnel boring machines (TBMs). Various indices determined from analysis of the force-penetration plot generated from indentation tests have been used to represent the drillability, boreability, and brittleness of rocks. However, no standard for the punch penetration test procedure or method for calculating the related indices has been suggested or adopted in the rock mechanics community. This paper introduces new indices based on the punch test to predict the performance of hard rock TBMs. A series of punch tests was performed on rock specimens representing six rock formations in Korea with different dimensions, i.e., the core specimens had different lengths and diameters. Of the indices obtained from the punch tests, the peak load index and mean load index showed good correlations with the cutting forces measured in full-scale linear cutting machine tests on the same rock types. The indices also showed good linear correlations with the ratio of uniaxial strength to Brazilian tensile strength, which indicates the brittleness of rock. The scale effect of using core specimens was investigated, and a preferred dimension for the punch test specimens is proposed. This paper also discusses the results of the punch test and full-scale rock cutting tests using LCM. The results of this study confirm that the proposed indices from the punch tests can be used to provide a reliable prediction of the cutting forces that act on a disc cutter. The estimated cutting forces can then be used for optimization of cutter-head design and performance prediction of hard rock TBMs.

  12. A new mechanism of injury for scaphoid fractures: 'test your strength' punch-bag machines.

    PubMed

    Sutton, P A; Clifford, O; Davis, T R C

    2010-06-01

    We investigated the mechanism of injury in a consecutive series of 153 confirmed scaphoid fractures. We found that ten (6%) occurred as a result of using a 'test your strength' punch-bag machine, a device found in public houses and amusement arcades. Clinicians should be aware that scaphoid fractures can occur as a result of punching these machines or other similar objects. PMID:20100710

  13. Design and performance of a punch mechanism based pellet injector for alternative injection in the large helical device

    SciTech Connect

    Mishra, J. S.; Sakamoto, R.; Motojima, G.; Matsuyama, A.; Yamada, H.

    2011-02-15

    A low speed single barrel pellet injector, using a mechanical punch device has been developed for alternative injection in the large helical device. A pellet is injected by the combined operation of a mechanical punch and a pneumatic propellant system. The pellet shape is cylindrical, 3 mm in diameter and 3 mm in length. Using this technique the speed of the pellet can be controlled flexibly in the range of 100-450 m/s, and a higher speed can be feasible for a higher gas pressure. The injector is equipped with a guide tube selector to direct the pellet to different injection locations. Pellets are exposed to several curved parts with the curvature radii R{sub c}= 0.8 and 0.3 m when they are transferred in guided tubes to the respective injection locations. Pellet speed variation with pressure at different pellet formation temperatures has been observed. Pellet intactness tests through these guide tubes show a variation in the intact speed limit over a range of pellet formation temperatures from 6.5 to 9.8 K. Pellet speed reduction of less than 6% has been observed after the pellet moves through the curved guide tubes.

  14. Design and performance of a punch mechanism based pellet injector for alternative injection in the large helical device

    NASA Astrophysics Data System (ADS)

    Mishra, J. S.; Sakamoto, R.; Motojima, G.; Matsuyama, A.; Yamada, H.

    2011-02-01

    A low speed single barrel pellet injector, using a mechanical punch device has been developed for alternative injection in the large helical device. A pellet is injected by the combined operation of a mechanical punch and a pneumatic propellant system. The pellet shape is cylindrical, 3 mm in diameter and 3 mm in length. Using this technique the speed of the pellet can be controlled flexibly in the range of 100-450 m/s, and a higher speed can be feasible for a higher gas pressure. The injector is equipped with a guide tube selector to direct the pellet to different injection locations. Pellets are exposed to several curved parts with the curvature radii Rc = 0.8 and 0.3 m when they are transferred in guided tubes to the respective injection locations. Pellet speed variation with pressure at different pellet formation temperatures has been observed. Pellet intactness tests through these guide tubes show a variation in the intact speed limit over a range of pellet formation temperatures from 6.5 to 9.8 K. Pellet speed reduction of less than 6% has been observed after the pellet moves through the curved guide tubes.

  15. Strength and Power Qualities Are Highly Associated With Punching Impact in Elite Amateur Boxers.

    PubMed

    Loturco, Irineu; Nakamura, Fabio Y; Artioli, Guilherme G; Kobal, Ronaldo; Kitamura, Katia; Cal Abad, Cesar C; Cruz, Igor F; Romano, Felipe; Pereira, Lucas A; Franchini, Emerson

    2016-01-01

    This study investigated the relationship between punching impact and selected strength and power variables in 15 amateur boxers from the Brazilian National Team (9 men and 6 women). Punching impact was assessed in the following conditions: 3 jabs starting from the standardized position, 3 crosses starting from the standardized position, 3 jabs starting from a self-selected position, and 3 crosses starting from a self-selected position. For punching tests, a force platform (1.02 × 0.76 m) covered by a body shield was mounted on the wall at a height of 1 m, perpendicular to the floor. The selected strength and power variables were vertical jump height (in squat jump and countermovement jump), mean propulsive power in the jump squat, bench press (BP), and bench throw, maximum isometric force in squat and BP, and rate of force development in the squat and BP. Sex and position main effects were observed, with higher impact for males compared with females (p ≤ 0.05) and the self-selected distance resulting in higher impact in the jab technique compared with the fixed distance (p ≤ 0.05). Finally, the correlations between strength/power variables and punching impact indices ranged between 0.67 and 0.85. Because of the strong associations between punching impact and strength/power variables (e.g., lower limb muscle power), this study provides important information for coaches to specifically design better training strategies to improve punching impact. PMID:26110348

  16. Is effective mass in combat sports punching above its weight?

    PubMed

    Lenetsky, Seth; Nates, Roy J; Brughelli, Matt; Harris, Nigel K

    2015-04-01

    The segmental and muscular complexity of the human body can result in challenges when examining the kinetics of impacts. To better understand this complexity, combat sports literature has selected effective mass as a measure of an athlete's inertial contribution to the momentum transfer during the impact of strikes. This measure helps to clarify the analysis of striking kinetics in combat sports. This paper will review: (1) effective mass as a concept and its usage as a measure of impact intensity in combat sports, (2) the neuromuscular pattern known as "double peak muscle activation" which has been theorized to help enhance initial hand velocity upon impact and joint stiffening during impact, (3) the methods and equations used to calculate effective mass, and (4) practitioner recommendations based on the literature. We will argue in this manuscript that the act of punching presents unique challenges to the current understanding of effective mass due to additional force application during impact. This review will improve the understanding of effective mass and its roles in effective striking serving to underpin future research into performance enhancement in striking based combat sports. PMID:25544341

  17. Dislocation punching from interfaces in functionally-graded materials

    SciTech Connect

    Taya, M.; Lee, J.K.; Mori, T.

    1997-06-01

    A new dislocation punching model for a functionally graded material (FGM) subjected to a temperature change is proposed, using Eshelby`s model. FGM, consisting of several layers, is deposited on a ceramic substrate. Two types of microstructures are examined for a layer: one consists of a metal matrix and ceramic particles and the other of a ceramic matrix and metal particles. An elastic energy is evaluated when plastic strain, in addition to thermal mismatch strain, is introduced in the metal phase. The work dissipated by the plastic deformation is also calculated. From the condition that the reduction in the elastic energy is larger than the work dissipated, a critical thermal mismatch strain to induce stress relaxation is determined. The magnitude of the plastic strain is also determined, when the relaxation occurs. The theory is applied to a model FGM consisting of mixtures of Pd and Al{sub 2}O{sub 3} on an Al{sub 2}O{sub 3} substrate.

  18. Shear fatigue crack growth - A literature survey

    NASA Technical Reports Server (NTRS)

    Liu, H. W.

    1985-01-01

    Recent studies of shear crack growth are reviewed, emphasizing test methods and data analyses. The combined mode I and mode II elastic crack tip stress fields are considered. The development and design of the compact shear specimen are described, and the results of fatigue crack growth tests using compact shear specimens are reviewed. The fatigue crack growth tests are discussed and the results of inclined cracks in tensile panels, center cracks in plates under biaxial loading, cracked beam specimens with combined bending and shear loading, center-cracked panels and double edge-cracked plates under cyclic shear loading are examined and analyzed in detail.

  19. Shear wave velocity for the upper 30 m: Combining a 3D voxel model and seismic CPTS for the Groningen gas field, the Netherlands.

    NASA Astrophysics Data System (ADS)

    Dambrink, Roula; Gunnink, Jan; Stafleu, Jan; de Lange, Ger; Kruiver, Pauline

    2016-04-01

    The Groningen gas field in the Netherlands is one of the largest gas fields of Europe and has been in production since the 1960's. Due to the progressive depletion of the reservoir, induced seismic activity has increased in recent years. In 2012, an earthquake of magnitude 3.6 initiated further research in prediction and management of risks related to man-induced earthquakes. Last year the government decided to reduce the gas extraction for this reason. One of the topics of concern is the large difference in earthquake-related damage to buildings which, in addition to the distance to the epicenter, appears to be also related to the composition of the shallow subsurface. To improve the spatial distribution of Shear Wave Velocities (Vs) in the shallow subsurface, used for hazard prediction, the Geological Survey of the Netherlands and Deltares constructed a Vs30 map of the upper 30 m of the gas field. In this map a high-resolution geological model (GeoTOP) is combined with seismic cone penetration tests (SCPT) from the area. The GeoTOP model is a 3D voxel model of the upper 50 m, in which each voxel (100x100x0.5 m) is attributed with lithostratigraphy and the most likely lithological class (peat, clay, fine sand, etc.). To obtain statistical distributions (with mean and standard deviation) of Vs for each combination of lithostratigraphical unit and lithoclass, 60 SCPTs were analyzed. In this way, it was possible to assign a specific Vs to each voxel in the model. For each voxel in the stack of voxels that covers the upper 30 m (i.e. 60 voxels), a Vs value was randomly drawn from the statistical distribution of the lithostratigraphical - lithoclass combination it belongs to. The Vs30 for each voxelstack is then calculated using the harmonic mean of the Vs of the 60 voxels. By repeating this procedure 100 times, an (average) Vs30 map and the uncertainty in Vs30 has been constructed. Using the procedure described above we were able to delineate zones with distinct Vs30

  20. Imaging of urban sinkhole structures - combination of P-wave and shear-wave reflection seismic profiling in the metropolitan region of Hamburg

    NASA Astrophysics Data System (ADS)

    Krawczyk, C. M.; Polom, U.; Dahm, T.

    2012-04-01

    The investigated roof region of a salt diapir in Hamburg, northern Germany, suffers sinkhole activity that was accompanied lately by microseismic events in the Gross Flottbek quarter. Thus, a high geohazard potential is present which can only be evaluated if highly resolved structural data are available. In addition to a shear-wave reflection seismic survey we performed with our shear-wave seismic system (ELVIS microvibrator, 120 m land streamer with 1 m SH-geophone distance), we also measured two P-wave reflection seismic profiles with the aim of imaging the top of the salt diapir. The LIAG- minivibrator and planted geophones of 5 m distance were used. The main profile runs along the major shear-wave line, the other crosses perpendicularly, so that a good areal coverage is given. Top salt is suggested at ca. 180 m depth, which is slightly deeper than previously thought from gravimetric measurements and larger-scale modelling. However, the general dip of the salt flank is further corroborated by additional gravimetric measurements. The surface of the salt dome undulates in the 10 m-range. Variable continuity of reflective elements and amplitude further characterize the top salt surface, which will be discussed in the context of fault and subrosion structures revealed from the shear-wave seismic experiment.

  1. Sheared Electroconvective Instability

    NASA Astrophysics Data System (ADS)

    Kwak, Rhokyun; Pham, Van Sang; Lim, Kiang Meng; Han, Jongyoon

    2012-11-01

    Recently, ion concentration polarization (ICP) and related phenomena draw attention from physicists, due to its importance in understanding electrochemical systems. Researchers have been actively studying, but the complexity of this multiscale, multiphysics phenomenon has been limitation for gaining a detailed picture. Here, we consider electroconvective(EC) instability initiated by ICP under pressure-driven flow, a scenario often found in electrochemical desalinations. Combining scaling analysis, experiment, and numerical modeling, we reveal unique behaviors of sheared EC: unidirectional vortex structures, its size selection and vortex propagation. Selected by balancing the external pressure gradient and the electric body force, which generates Hagen-Poiseuille(HP) flow and vortical EC, the dimensionless EC thickness scales as (φ2 /UHP)1/3. The pressure-driven flow(or shear) suppresses unfavorably-directed vortices, and simultaneously pushes favorably-directed vortices with constant speed, which is linearly proportional to the total shear of HP flow. This is the first systematic characterization of sheared EC, which has significant implications on the optimization of electrodialysis and other electrochemical systems.

  2. Structural evolution of regenerated silk fibroin under shear: Combined wide- and small-angle x-ray scattering experiments using synchrotron radiation

    SciTech Connect

    Rossle, Manfred; Panine, Pierre; Urban, Volker S; Riekel, Christine

    2004-04-01

    The structural evolution of regenerated Bombyx mori silk fibroin during shearing with a Couette cell has been studied in situ by synchrotron radiation small- and wide-angle x-ray scattering techniques. An elongation of fibroin molecules was observed with increasing shear rate, followed by an aggregation phase. The aggregates were found to be amorphous with {beta}-conformation according to infrared spectroscopy. Scanning x-ray microdiffraction with a 5 {micro}m beam on aggregated material, which had solidified in air, showed silk II reflections and a material with equatorial reflections close to the silk I structure reflections, but with strong differences in reflection intensities. This silk I type material shows up to two low-angle peaks suggesting the presence of water molecules that might be intercalated between hydrogen-bonded sheets.

  3. Mesoscopic Nonlinear Elastic Modulus of Thermal Barrier Coatings Determined by Cylindrical Punch Indentation

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.; Zhu, Dong-Ming; Miller, Robert A.

    2000-01-01

    Cylindrical punch indentations are performed to determine the effective modulus of a plasma-sprayed ZrO2-8Wt%Y2O3 thermal barrier coating (TBC) as a function of coating depth. Cylindrical punch indentations offer significant advantages over pointed (Vickers, Berkovich, or Knoop) indentations for materials that do not exhibit linear elastic behavior. Cyclic loading with a cylindrical punch clearly shows the TBCs to exhibit nonlinear elastic behavior with significant hysteresis that is related to the compaction and internal sliding within the plasma-spray splat microstructure. In addition, the effect of a high heat flux laser treatment was shown to produce a gradient both in the effective TBC modulus and degree of loading/unloading hysteresis with depth.

  4. Development of a new superficial punch for Descemet's Membrane Endothelial Keratoplasty donor tissue preparation.

    PubMed

    Ruzza, Alessandro; Parekh, Mohit; Salvalaio, Gianni; Ferrari, Stefano; Ponzin, Diego

    2016-04-01

    Endothelial Keratoplasty (EK) is a corneal surgical procedure that allows a selective transplantation of the posterior layer of the cornea. Descemet's Membrane Endothelial Keratoplasty (DMEK) is one of the EK procedures in which the diseased Descemet's Membrane and the endothelium are replaced with a healthy donor tissue. To achieve this, the donor cornea is cut superficially from the endothelial side and the tissue can be separated using specific instruments like Pierse Notched, Acute or Fogla forceps. However, the pressure required to punch the superficial layer has always been a challenge and therefore a calibrated device to punch and excise the required superficial layer has been designed. This new model of punch will help to identify the peripheral edge of the DMEK lenticule which in turn helps to excise the tissue exclusively, further reducing the donor tissue wastage, as seen with the current tissue preparation methods. PMID:26305003

  5. Comparison of aerogrids and punched plates for smoothing flow from short annular diffusers

    NASA Technical Reports Server (NTRS)

    Rumpf, R. L.; Shippen, W. B.

    1972-01-01

    Scale model tests were conducted to evaluate the effectiveness of aerogrids and punched plates in producing flat velocity profiles downstream of short diffusers as would be used between the compressor and combustor of advanced aircraft engines. The diffuser had an area ratio of 4.17 and a length-to-inlet-height ratio of 2.07. The aerogrids tested were plates containing 1123 contoured venturis in parallel with geometric blockages of 83, 74, and 61 percent, respectively. The punched plates contained 1123 sharp-edged orifices with blockages of 58 and 30 percent. The results show that aerogrids, with higher effective blockage for the same pressure loss, are more effective flow-smoothing devices than the punched plates. Also, the overall pressure loss decreases and the exit velocity profile becomes flatter as either type of grid is moved closer to the diffuser exit plane.

  6. Assessment of mechanical properties of the martensitic steel EUROFER97 by means of punch tests

    NASA Astrophysics Data System (ADS)

    Ruan, Y.; Spätig, P.; Victoria, M.

    2002-12-01

    The ball punch test technique was used to evaluate the conventional tensile and impact properties of the tempered martensitic steel EUROFER97 from room temperature down to liquid nitrogen temperature. The testing was carried out on unirradiated material only with small disks, 3 mm in diameter and 0.25 mm in thickness. For comparison, tensile tests were also performed over the same temperature range. Correlations between the load at the plastic bending initiation and the maximum load of the punch tests with the yield stress and the ultimate tensile stress of the tension tests could be established. The temperature dependence of the specific fracture energy of the punch test was used to define a ductile-brittle transition temperature (DBTT) and to correlate this with the DBTT measured from impact Charpy on KLST specimens. The results are compared with other available correlations done in the past on other ferritic steels.

  7. Influence of Punch Geometry on Process Parameters in Cold Backward Extrusion

    NASA Astrophysics Data System (ADS)

    Plančak, M.; Barišić, B.; Car, Z.; Movrin, D.

    2011-01-01

    In cold extrusion of steel tools make direct contact with the metal to be extruded. Those tools are exposed to high contact stresses which, in certain cases, may be limiting factors in applying this technology. The present paper was bound to the influence of punch head design on radial stress at the container wall in the process of cold backward extrusion. Five different punch head geometries were investigated. Radial stress on the container wall was measured by pin load cell technique. Special tooling for the experimental investigation was designed and made. Process has been analyzed also by FE method. 2D models of tools were obtained by UGS NX and for FE analysis Simufact Forming GP software was used. Obtained results (experimental and obtained by FE) were compared and analyzed. Optimal punch head geometry has been suggested.

  8. Determination of the toughness of in-service steam turbine disks using small punch testing

    NASA Astrophysics Data System (ADS)

    Foulds, J.; Viswanathan, R.

    2001-10-01

    Knowledge of the material toughness is crucial in assessing the integrity of heavy section steel components. Conventional tests to determine the toughness involve extraction of large blocks of materials and therefore are not practical on in-service components. On the other hand, conservative assumptions regarding toughness without regard to actual data can lead to expensive and premature replacement of the components. Previous EPRI studies have demonstrated the use of a relatively nondestructive technique termed the "small punch test" to estimate the fracture appearance transition temperature (FATT) and fracture toughness ( K Ic ) of high-temperature turbine rotor steels and nuclear reactor pressure vessel steels. This paper summarizes the results of research into the feasibility of extending the small punch test to characterize the toughness of the 3 to 3.5% NiCrMoV (3-3.5NiCrMoV) low alloy steel used for fossil and nuclear power plant low-pressure (LP) steam turbine disks. Results of the present study show that the small punch transition temperature, T sp , is linearly correlated with FATT, so that measurement of T sp permits estimation of the standard Charpy FATT through empirical use of the correlation. The statistical confidence prediction uncertainty bands for the correlation were found to be narrow enough to make the small punch- based FATT estimation practical for this alloy. Additionally, independent K Ic measurements made by PowerGen, UK, on some of the same test materials were in excellent agreement with measurements made here, indicating that the small punch K Ic measurement can be reproducible across laboratories. Limited testing for fracture initiation toughness showed, as has been demonstrated for other materials, that the small punch test-based initiation fracture toughness ( K Ic ) determination was within ±25% of the ASTM standard measurement of K Ic , suggesting that the test method can be used for direct determination of fracture initiation

  9. Role of multiwalled carbon nanotube in interlaminar shear strength of epoxy/glass fiber/multi walled carbon nanotube hybrid composites

    NASA Astrophysics Data System (ADS)

    Srinivasan Chandrasekaran, Vasan Churchill

    2011-12-01

    The motivation of this thesis is to investigate the role of multi-walled carbon nanotube (MWCNT) in enhancing the interlaminar shear strength (ILSS) of hybrid composites. The objective of this thesis is to understand the relationships between processing history, material variability, matrix properties, glass fiber/matrix interface properties and their correlations with interlaminar shear strength of hybrid composites. The interlaminar shear strength (ILSS) of hybrid composites made from glass fiber and multi-walled carbon nanotube (MWCNT) modified epoxy is compared with that for unmodified epoxy/glass fiber composites (control). By combining the techniques of high speed mechanical stirring and ultrasonic agitation, 0.5% MWCNT by weight were dispersed in epoxy to prepare a suspension. Composites were manufactured by both injection double vacuum-assisted resin transfer molding (IDVARTM) and the flow flooding chamber (FFC) methods. Compression shear tests (CST) were conducted on the manufactured samples to determine the ILSS. The effect of processing history and batch-to-batch variability of materials---glass fiber preform, resin and carbon nanotubes---on the ILSS of samples made by both techniques was investigated. Statistical comparison of the measured ILSS values for hybrid composites with the control specimens clearly show that hybrid composites made by the FFC process resulted in significant ILSS enhancement relative to the control and the IDVARTM specimens. After it was established that the FFC process improved the ILSS, the effect of functionalizing the nanotubes was explored. Multi walled carbon nanotubes (MWCNT) were oxidized by acid treatment and heated with triethylene tetra amine (TETA) to obtain amino functionalized MWCNTs (f-MWCNT). Hybrid composites with f-MWCNTs were manufactured using FFC technique and control samples were fabricated using the same E-Glass fiber mat and unmodified epoxy resin subjected to the same processing history. CST results show

  10. Personality and the Success of Card-Punch Operators in Training

    ERIC Educational Resources Information Center

    Savage, R. Douglass; Stewart, Ronald R.

    1972-01-01

    In the card-punch operating training described here, it seems that extraversion is more important in job success in the early stages of training and clerical aptitude less so, with the relative importance of these attributes being reversed at a later stage. (Authors)

  11. Randomization of Symbol Repetition of Punch Cards with Superimposed Coding in Information-Search Systems.

    ERIC Educational Resources Information Center

    Pirovich, L. Ya

    The article shows the effect of the irregularity of using separate symbols on search noise on punch cards with superimposed symbol coding in information-search system (IPS). A binomial law of random value distribution of repetition of each symbol is established and analyzed. A method of determining the maximum value of symbol repetition is…

  12. Computing Gross Pay from Punched Time Cards. Student Manual and Instructor's Manual.

    ERIC Educational Resources Information Center

    McElveen, Peggy C.

    Supporting performance objective 30 of the V-TECS (Vocational-Technical Education Consortium of States) Secretarial Catalog, both a set of student materials and an instructor's manual on computing gross pay from punched time cards are included in this packet, which is part of a series. The student materials include a group of time cards,…

  13. Effect of feeding fermented rice punch on oestrous induction in anoestrous bitches

    PubMed Central

    Choi, Eul-Soo; Yang, Byoung-Chul; Park, Pu-Rum; Chae, Jung-Il; Kim, Dong-Ku; Yoo, Jae-Kyu; Kim, Dong-Hoon; Cho, Kyu-Woan; Kong, Il-Keun

    2015-01-01

    Introduction As a consequence of poor productivity caused by a long anoestrous period, considerable research effort has been given to oestrus induction in dogs to enhance the productivity of young dogs and to preserve breeds. Materials and methods Oestrus was induced in 30 anoestrous bitches more than three months after the last oestrus. Bitches orally received fermented rice punch with or without bromocriptine once daily for 21 consecutive days. The bitches were divided into two groups (n=10 per group): Group (1) fed fermented rice punch and Group (2) administered bromocriptine (100 µg/kg/day) and fed fermented rice punch. Results The concentration of dopamine in fermented rice punch was 47.2 mg/kg (parts per million). Six of 10 (60.0 per cent) and seven of 10 (70.0 per cent) bitches showed pro-oestrual bleeding in Groups 1 and 2, respectively. The mean and median values (min–max) to oestrus induction was not significantly different between Groups 1 and 2 (9.7±7.3, 6.5 (3–22) and 11.3±6.6, 7.9 (5–21) days) after treatment commencement (P>0.05). The pregnancy rate was very similar between Groups 1, 2 (66.0%) and control (66.0, 57.0 and 50.0 per cent). The mean and median values (min–max) of pups per bitch are also not significantly different between Groups 1, 2 and control (7.0±1.8, 7.0 (5–9) and 7.5±2.1, 7.5 (5–10) and 7.0±0, 7.0 (7–7)). Conclusion We suggest that rice punch effectively induces oestrus in bitches. PMID:26392895

  14. Multidrug punch cards in primary care: a mixed methods study on patients' preferences and impact on adherence

    PubMed Central

    Boeni, Fabienne; Hersberger, Kurt E.; Arnet, Isabelle

    2014-01-01

    Background: Multidrug punch cards are frame cards with 28 plastic cavities filled with a patient's oral solid medication. They are used in primary care to facilitate medication management and to enhance adherence. Main criticism concerned handling difficulties and fading knowledge about medication of patients using them. This study aimed at exploring daily use, preferences, and adherence of primary care patients using multidrug punch cards. Methods: Community pharmacies in Switzerland recruited primary care patients using multidrug punch cards. A mixed methods approach was applied with quantitative interviews performed by telephone and qualitative interviews face-to-face. Results: Of 149 eligible patients from 21 community pharmacies, 22 participated 2011 in the quantitative and 11 participated 2013/14 in the qualitative interview. Patients were very satisfied with the multidrug punch cards and stated increased medication safety. All considered adherence as very important. Self-reported adherence was 10 (median) on a visual analog scale (0 = no intake, 10 = perfect adherence). The absence of package inserts and predefined handling difficulties e.g., tablets spiking at removal were not perceived as problems. Conclusions: Patients are satisfied with the multidrug punch cards, feel safe, mostly have no handling problems and adhere to their treatment. Trust in health-care professionals and patients' experiences emerged as key variables for initiating multidrug punch card use and for medication adherence. This mixed methods study invalidates previous concerns about disadvantages of multidrug punch cards. Health-care professionals should actively recommend them for primary care patients with polypharmacy and poor adherence. PMID:25324777

  15. Transfer of momentum from different arm segments to a light movable target during a straight punch thrown by expert boxers.

    PubMed

    Nakano, Genki; Iino, Yoichi; Imura, Akiko; Kojima, Takeji

    2014-01-01

    The aim of this study was to determine the relationship between the reductions in momentum of punching arm segments and the impulse of the impact force when boxers throw a punch at a movable target with a mass almost equal to that of the human head. Nine male expert collegiate boxers threw a rear-hand straight punch at the target with their full effort. The reductions in momentum of the upper arm, forearm and fist plus glove of the punching arm during impact and the impulse were determined using a motion capture system and an accelerometer attached to the target. The reduction in momentum of the punching arm explained approximately 95% of the impulse: 40%, 35% and 20% for the upper arm, forearm and fist plus glove, respectively. The Pearson correlation coefficient between the peak and impulse of the impact force was 0.902. These results suggest that for boxers increasing the momentum of the punching arm rather than that of the other body segments immediately before the impact is effective at increasing the impulse of the punch into the face of an opponent. PMID:24404907

  16. Isogeometric analysis of shear bands

    NASA Astrophysics Data System (ADS)

    Berger-Vergiat, Luc; McAuliffe, Colin; Waisman, Haim

    2014-08-01

    Numerical modeling of shear bands present several challenges, primarily due to strain softening, strong nonlinear multiphysics coupling, and steep solution gradients with fine solution features. In general it is not known a priori where a shear band will form or propagate, thus adaptive refinement is sometimes necessary to increase the resolution near the band. In this work we explore the use of isogeometric analysis for shear band problems by constructing and testing several combinations of NURBS elements for a mixed finite element shear band formulation. Owing to the higher order continuity of the NURBS basis, fine solution features such as shear bands can be resolved accurately and efficiently without adaptive refinement. The results are compared to a mixed element formulation with linear functions for displacement and temperature and Pian-Sumihara shape functions for stress. We find that an element based on high order NURBS functions for displacement, temperature and stress, combined with gauss point sampling of the plastic strain leads to attractive results in terms of rate of convergence, accuracy and cpu time. This element is implemented with a -bar strain projection method and is shown to be nearly locking free.

  17. 29 CFR 570.59 - Occupations involved in the operations of power-driven metal forming, punching, and shearing...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Occupations involved in the operations of power-driven... REGULATIONS, ORDERS AND STATEMENTS OF INTERPRETATION Occupations Particularly Hazardous for the Employment of Minors Between 16 and 18 Years of Age or Detrimental to Their Health or Well-Being § 570.59...

  18. 29 CFR 570.59 - Occupations involved in the operation of power-driven metal forming, punching, and shearing...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Occupations involved in the operation of power-driven metal..., ORDERS AND STATEMENTS OF INTERPRETATION Occupations Particularly Hazardous for the Employment of Minors Between 16 and 18 Years of Age or Detrimental to Their Health or Well-Being § 570.59 Occupations...

  19. Added Punch with PowerPoint: College Students Combine PowerPoint and Multicultural Music

    ERIC Educational Resources Information Center

    Miller, Brigetta F.

    2004-01-01

    While working with music teachers in training at the university level, the author learned how helpful it can be to model a curriculum that mirrors America's changing demographics. As a Native American who grew up on the Stockbridge-Munsee Indian Reservation, in central Wisconsin, she discovered that Native history and culture were absent from…

  20. Combined effects of the in-plane orientation angle and the loading angle on the dynamic enhancement of honeycombs under mixed shear-compression loading

    NASA Astrophysics Data System (ADS)

    Tounsi, R.; Markiewicz, E.; Haugou, G.; Chaari, F.; Zouari, B.

    2016-05-01

    The combined effect of the loading angle (ψ) and the in-plane orientation angle (β) on the dynamic enhancement of aluminium alloy honeycombs is investigated. Experimental results are analysed on the crushing surfaces (initial peak and average crushing forces). A significant effect of the loading angle is reported. The dynamic enhancement rate depends on the loading angle until a critical loading angle (ψcritical). Beyond, a negative dynamic enhancement rate is observed. Concerning the in-plane orientation angle β effect, it depends on the loading angle ψ under quasi-static conditions. Under dynamic conditions, a significant effect is reported independently of the loading angle ψ. Therefore, the dynamic enhancement rate depends on the combined effects of ψ and β angles. A global analysis of the buckling mechanisms allowed us to explain the combined effect of ψ and β angles on the initial peak force. The collapse mechanisms analysis explain the negative dynamic enhancement rate for large loading angles.

  1. Love-type wave propagation in a pre-stressed viscoelastic medium influenced by smooth moving punch

    NASA Astrophysics Data System (ADS)

    Singh, A. K.; Parween, Z.; Chatterjee, M.; Chattopadhyay, A.

    2015-04-01

    In the present paper, a mathematical model studying the effect of smooth moving semi-infinite punch on the propagation of Love-type wave in an initially stressed viscoelastic strip is developed. The dynamic stress concentration due to the punch for the force of a constant intensity has been obtained in the closed form. Method based on Weiner-hopf technique which is indicated by Matczynski has been employed. The study manifests the significant effect of various affecting parameters viz. speed of moving punch associated with Love-type wave speed, horizontal compressive/tensile initial stress, vertical compressive/tensile initial stress, frequency parameter, and viscoelastic parameter on dynamic stress concentration due to semi-infinite punch. Moreover, some important peculiarities have been traced out and depicted by means of graphs.

  2. Small punch testing for determining the material toughness of low alloy steel components in service

    SciTech Connect

    Foulds, J. ); Viswanathan, R. )

    1994-10-01

    The toughness of the low alloy ferritic steel material of structural components operating at elevated temperatures can degrade during service due to embrittling phenomena such as carbide coarsening and temper embrittlement. The extent of degradation and the current level of toughness are critical inputs to component structural integrity assessments and to operation and maintenance planning. Conventional test methods for measuring toughness require the removal of large material samples from the in-service component, which is generally impractical. However, the recent development of relatively nondestructive, miniature sample removal systems and the small punch test technique (which utilizes nonstandard, miniature specimens) now provides a convenient, practical means of evaluating the material of an in-service component for toughness and related mechanical properties. This paper describes the small punch test technique with selected examples of its application to various grades of low alloy ferritic steel.

  3. [Possibilities for injuries caused by rubber bullets from the self-defense weapon MR 35 Punch].

    PubMed

    Schyma, C; Schyma, P

    1997-01-01

    Manurhin developed a "non lethal" weapon, the MR 35 Punch, which fires 21 g weighing rubber balls of 35 mm caliber. The black powder cartridges which were used as propellant cause important variations of the projectile's velocity from 120 to 140 m/s. The resulting energies were about 150 to 200 J. The wounding potential was examined by shots on different materials and gelatin. Shots from 2 to 5 m distance caused penetrations of 3 to 8 cm in 10 percent gelatin. Covering the gelatin with skin or thick textiles did not significantly change the penetration. Skin and textiles were penetrated in all experiments. Pieces of flat bone which were embedded in gelatin were fractured by the shots, in part fracture elements were dislocated. The discussion of the wound ballistic results contradict the "non lethal" character of the MR 35 Punch. PMID:9446526

  4. A quasi-analytical breakdown voltage model in four-layer punch-through TVS devices

    NASA Astrophysics Data System (ADS)

    Urresti, Jesus; Hidalgo, Salvador; Flores, David; Roig, Jaume; Rebollo, José; Mazarredo, Imanol

    2005-08-01

    A quasi-analytical model addressed to predict the breakdown voltage in four-layer transient voltage suppressor (TVS) diodes based on the punch-through effect is reported in this paper. For breakdown voltage in excess of 1 V, a closed form expression is derived. In addition, the three-layer TVS diode can also be described with the developed model. Finally, results obtained from the model are in good agreement with simulation and experimental data.

  5. Pseudo-viscosity analysis of dynamic compactions of multilayer copper powder medium by punch impact

    SciTech Connect

    Tokushima, Koji; Sano, Yukio

    1995-08-01

    In this paper, the compaction of a multilayer copper powder medium by punch impact is analyzed by a pseudo-viscosity method: equal thickness layers of lower (L) and higher (H) initial densities are arranged alternately. In the early stage of compaction, reflection and transmission of induced shock and elastic waves occur at the interfaces in the medium. As a result, the L layers are selectively compressed at first until the density distribution in the medium is uniform. Compaction then continues by the shock waves propagating through the medium. The final mean is influenced greatly by die wall friction. The influence is less in the L-H type arrangement where an L layer is in direct contact with the punch than in the H-L type arrangement for a given number of layers, because energy loss due to wall friction is smaller in the former. Separation of the punch from the medium and subsequent reimpingement was found to occur in some of the H-L type compactions.

  6. Using Teamcenter engineering software for a successive punching tool lifecycle management

    NASA Astrophysics Data System (ADS)

    Blaga, F.; Pele, A.-V.; Stǎnǎşel, I.; Buidoş, T.; Hule, V.

    2015-11-01

    The paper presents studies and researches results of the implementation of Teamcenter (TC) integrated management of a product lifecycle, in a virtual enterprise. The results are able to be implemented also in a real enterprise. The product was considered a successive punching and cutting tool, designed to materialize a metal sheet part. The paper defines the technical documentation flow (flow of information) in the process of constructive computer aided design of the tool. After the design phase is completed a list of parts is generated containing standard or manufactured components (BOM, Bill of Materials). The BOM may be exported to MS Excel (.xls) format and can be transferred to other departments of the company in order to supply the necessary materials and resources to achieve the final product. This paper describes the procedure to modify or change certain dimensions of sheet metal part obtained by punching. After 3D and 2D design, the digital prototype of punching tool moves to following lifecycle phase of the manufacturing process. For each operation of the technological process the corresponding phases are described in detail. Teamcenter enables to describe manufacturing company structure, underlying workstations that carry out various operations of manufacturing process. The paper revealed that the implementation of Teamcenter PDM in a company, improves efficiency of managing product information, eliminating time working with search, verification and correction of documentation, while ensuring the uniqueness and completeness of the product data.

  7. Dermabrasion-Loo-punch-excision technique for the treatment of acne-induced osteoma cutis.

    PubMed

    Fulton, J E

    1987-06-01

    Three patients with chronic osteoma cutis secondary to acne vulgaris were treated with the dermabrasion-Loo-punch-excision technique. Under regional nerve block with lidocaine-bipuvacaine (50:50) a uniform dermabrasion was performed across the entire face, including the hairline and 1 cm below the jawline. This exposed the foci of osteoma cutis. Then the appropriate sized Loo punch (usually the 2.0- or the 2.5-mm punch) was used to excise the bluish-gray miliary lesions. The majority of the foci were removed in one operation. Following excision, the lesions were closed with 7-0 prolene suture. To prevent crust formation postoperatively, Aloe-vera-soaked polyethylene oxide gel dressings (Vigilon) were changed twice daily following an ice water compress. Sutures were removed rapidly in 5 to 7 days to prevent the appearance of suture lines. Although one patient required an additional procedure, the cosmetic results were excellent. Only a few small residual blue "dot" lesions remained in these three cases. PMID:2953769

  8. Reduced shear power spectrum

    SciTech Connect

    Dodelson, Scott; Shapiro, Charles; White, Martin J.; /UC, Berkeley, Astron. Dept. /UC, Berkeley

    2005-08-01

    Measurements of ellipticities of background galaxies are sensitive to the reduced shear, the cosmic shear divided by (1-{kappa}) where {kappa} is the projected density field. They compute the difference between shear and reduced shear both analytically and with simulations. The difference becomes more important an smaller scales, and will impact cosmological parameter estimation from upcoming experiments. A simple recipe is presented to carry out the required correction.

  9. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  10. Novel shear mechanism in nanolayered composites

    SciTech Connect

    Mara, Nathan; Bhattacharyya, Dhriti; Hirth, John P; Dickerson, Patricia O; Misra, Amit

    2009-01-01

    Recent studies have shown that two-phase nanocomposite materials with semicoherent interfaces exhibit enhanced strength, deformability, and radiation damage resistance. The remarkable behavior exhibited by these materials has been attributed to the atomistic structure of the bi-metal interface that results in interfaces with low shear strength and hence, strong barriers for slip transmission due to dislocation core spreading along the weak interfaces. In this work, the low interfacial shear strength of Cu/Nb nanoscale multilayers dictates a new mechanism for shear banding and strain softening during micropillar compression. Previous work investigating shear band formation in nanocrystalline materials has shown a connection between insufficient strain hardening and the onset of shear banding in Fe and Fe-10% Cu, but has also shown that hardening does not necessarily offset shear banding in Pd nanomaterials. Therefore, the mechanisms behind shear localization in nanocrystalline materials are not completely understood. Our findings, supported by molecular dynamics simulations, provide insight on the design of nanocomposites with tailored interface structures and geometry to obtain a combination of high strength and deformability. High strength is derived from the ability of the interfaces to trap dislocations through relative ease of interfacial shear, while deformability can be maximized by controlling the effects of loading geometry on shear band formation.

  11. Shear wave mapping of skeletal muscle using shear wave wavefront reconstruction based on ultrasound color flow imaging

    NASA Astrophysics Data System (ADS)

    Yamakoshi, Yoshiki; Yamamoto, Atsushi; Kasahara, Toshihiro; Iijima, Tomohiro; Yuminaka, Yasushi

    2015-07-01

    We have proposed a quantitative shear wave imaging technique for continuous shear wave excitation. Shear wave wavefront is observed directly by color flow imaging using a general-purpose ultrasonic imaging system. In this study, the proposed method is applied to experiments in vivo, and shear wave maps, namely, the shear wave phase map, which shows the shear wave propagation inside the medium, and the shear wave velocity map, are observed for the skeletal muscle in the shoulder. To excite the shear wave inside the skeletal muscle of the shoulder, a hybrid ultrasonic wave transducer, which combines a small vibrator with an ultrasonic wave probe, is adopted. The shear wave velocity of supraspinatus muscle, which is measured by the proposed method, is 4.11 ± 0.06 m/s (N = 4). This value is consistent with those obtained by the acoustic radiation force impulse method.

  12. Aligning self-assembled gelators by drying under shear.

    PubMed

    Draper, Emily R; Mykhaylyk, Oleksandr O; Adams, Dave J

    2016-05-25

    We show how drying under shear can be used to prepare aligned fibres and worm-like micelles from low molecular weight gelators. Shearing followed by drying leads to the dealignment before the water can be removed; continuous shear whilst drying is required to maintain the alignment. Combining a slow pH change with continuous shear allows alignment of the gelling fibres, which can then be dried. PMID:27146964

  13. Himalia and Phoebe: Little moons that punch above their weight

    NASA Astrophysics Data System (ADS)

    LI, Daohai; Christou, Apostolos

    2016-05-01

    Small bodies in the solar system are usually treated as massless particles. While a sufficient approximation for many purposes, the small but finite mass of some of these (mass ratio μ=10^{-10}-10^{-8} of primary) can have observable consequences on the local population. Numerical experiments have shown this to be true for the orbital neighbourhood of Himalia, a prograde irregular moon of Jupiter (Christou 2005). In a recent demonstration of the same mechanism in a different context, Novaković et al. (2015) showed that the dwarf planet Ceres activates its own secular resonances, causing the long-term diffusion of asteroids in the middle part of the Main Belt.Seeking to better understand the dynamics caused by “internecine” interactions, we have constructed a semi-analytical model of a test particle’s secular evolution in the Sun-Planet-massive moon-particle restricted 4-body problem. By combining the Kozai-Lidov formalism with a model of coorbital motion valid for non-planar & non-circular orbits (Namouni 1999) we have overcome the difficulty in treating the interaction between potentially-crossing neighbouring orbits.We have applied this model to the cases of (a) J6 Himalia, a jovian irregular satellite (μ≃ 2× 10^{-9}) and the largest in a family of five moons, and (b) S9 Phoebe, a retrograde irregular moon of Saturn with μ=1.5× 10^{-8} which, curiously, is not associated with a family (Ćuk et al. 2003). We observe numerous instances of capture into secular resonances where the critical angle is a linear combination of the relative nodes and apses of the particle and the perturber. In particular we are able to reproduce the libration of the differential node found by Christou (2005). We generate fictitious families of test particles around Himalia and Phoebe and find that, while ~8% of local phase space is occupied by these resonances for Himalia, this figure is ~16% for Phoebe. We confirm these results using N-body integrations of the full

  14. Characterization of mechanical properties of aluminized coatings in advanced gas turbine blades using a small punch method

    SciTech Connect

    Sugita, Y.; Ito, M.; Sakurai, S.; Bloomer, T.E.; Kameda, J. |

    1997-04-01

    Advanced technologies of superalloy casting and coatings enable one to enhance the performance of combined cycle gas turbines for electric power generation by increasing the firing temperature. This paper describes examination of the microstructure/composition and mechanical properties (22--950 C) in aluminized CoCrAlY coatings of advanced gas turbine blades using scanning Auger microprobe and a small punch (SP) testing method. Aluminized coatings consisted of layered structure divided into four regimes: (1) Al enriched and Cr depleted region, (2) Al and Cr graded region, (3) fine grained microstructure with a mixture of Al and Cr enriched phases and (4) Ni/Co interdiffusion zone adjacent to the interface. SP specimens were prepared in order that the specimen surface would be located in the various coating regions. SP tests indicated strong dependence of the fracture properties on the various coatings regimes. Coatings 1 and 2 with very high microhardness showed much easier formation of brittle cracks in a wide temperature range, compared to coatings 3 and 4 although the coating 2 had ductility improvement at 950 C. The coating 3 had lower room temperature ductility than the coating 4. However, the ductility in the coating 3 exceeded that in the region 4 above 730 C due to a precipitous ductility increase. The integrity of aluminized coatings while in-service is discussed in light of the variation of the low cycle fatigue life as well as the ductility in the layered structure.

  15. Chemical Punch Packed in Venoms Makes Centipedes Excellent Predators*

    PubMed Central

    Yang, Shilong; Liu, Zhonghua; Xiao, Yao; Li, Yuan; Rong, Mingqiang; Liang, Songping; Zhang, Zhiye; Yu, Haining; King, Glenn F.; Lai, Ren

    2012-01-01

    Centipedes are excellent predatory arthropods that inject venom to kill or immobilize their prey. Although centipedes have long been known to be venomous, their venoms remain largely unexplored. The chemical components responsible for centipede predation and the functional mechanisms are unknown. Twenty-six neurotoxin-like peptides belonging to ten groups were identified from the centipede venoms, Scolopendra subspinipes mutilans L. Koch by peptidomics combined with transcriptome analysis, revealing the diversity of neurotoxins. These neurotoxins each contain two to four intramolecular disulfide bridges, and in most cases the disulfide framework is different from that found in neurotoxins from the venoms of spiders, scorpions, marine cone snails, sea anemones, and snakes (5S animals). Several neurotoxins contain potential insecticidal abilities, and they are found to act on voltage-gated sodium, potassium, and calcium channels, respectively. Although these neurotoxins are functionally similar to the disulfide-rich neurotoxins found in the venoms of 5S animals in that they modulate the activity of voltage-gated ion channels, in almost all cases the primary structures of the centipede venom peptides are unique. This represents an interesting case of convergent evolution in which different venomous animals have evolved different molecular strategies for targeting the same ion channels in prey and predators. Moreover, the high level of biochemical diversity revealed in this study suggests that centipede venoms might be attractive subjects for prospecting and screening for peptide candidates with potential pharmaceutical or agrochemical applications. PMID:22595790

  16. Shear wavelength estimation based on inverse filtering and multiple-point shear wave generation

    NASA Astrophysics Data System (ADS)

    Kitazaki, Tomoaki; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

    2016-07-01

    Elastography provides important diagnostic information because tissue elasticity is related to pathological conditions. For example, in a mammary gland, higher grade malignancies yield harder tumors. Estimating shear wave speed enables the quantification of tissue elasticity imaging using time-of-flight. However, time-of-flight measurement is based on an assumption about the propagation direction of a shear wave which is highly affected by reflection and refraction, and thus might cause an artifact. An alternative elasticity estimation approach based on shear wavelength was proposed and applied to passive configurations. To determine the elasticity of tissue more quickly and more accurately, we proposed a new method for shear wave elasticity imaging that combines the shear wavelength approach and inverse filtering with multiple shear wave sources induced by acoustic radiation force (ARF). The feasibility of the proposed method was verified using an elasticity phantom with a hard inclusion.

  17. Mechanical Behavior of Lithium-Ion Batteries and Fatigue Behavior of Ultrasonic Weld-Bonded Lap-Shear Specimens of Dissimilar Magnesium and Steel Sheets

    NASA Astrophysics Data System (ADS)

    Lai, Wei-Jen

    The mechanical behaviors of LiFePO4 battery cell and module specimens under in-plane constrained compression were investigated for simulations of battery cells, modules and packs under crush conditions. The experimental stress-strain curves were correlated to the deformation patterns of battery cell and module specimens. Analytical solutions were developed to estimate the buckling stresses and to provide a theoretical basis for future design of representative volume element cell and module specimens. A physical kinematics model for formation of kinks and shear bands in battery cells was developed to explain the deformation mechanism for layered battery cells under in-plane constrained compression. A small-scale module constrained punch indentation test was also conducted to benchmark the computational results. The computational results indicate that macro homogenized material models can be used to simulate battery modules under crush conditions. Fatigue behavior and failure modes of ultrasonic spot welds in lap-shear specimens of magnesium and steel sheets with and without adhesive were investigated. For ultrasonic spot welded lap-shear specimens, the failure mode changes from the partial nugget pullout mode under low-cycle loading conditions to the kinked crack failure mode under high-cycle loading conditions. For adhesive-bonded and weld-bonded lap-shear specimens, the test results show the near interface cohesive failure mode and the kinked crack failure mode under low-cycle and high-cycle loading conditions, respectively. Next, the analytical effective stress intensity factor solutions for main cracks in lap-shear specimens of three dissimilar sheets under plane strain conditions were developed and the solutions agreed well with the computational results. The analytical effective stress intensity factor solutions for kinked cracks were compared with the computational results at small kink lengths. The results indicate that the computational results approach to

  18. Shear jamming in granular materials

    NASA Astrophysics Data System (ADS)

    Zhang, Jie

    2013-11-01

    For frictionless particles with purely repulsive interactions, there is a critical packing fraction ϕJ below which no jammed states exist. Recent experiments have shown that applying shear to a stress-free initial state can generate states which are either fragile or shear jammed depending on the way the force-network is percolated (Bi et al. Nature 2011). The nature of the jamming transition however is obscured because the existence of friction between the system and the third dimension. A new apparatus at SJTU has been designed to completely eliminate this friction by letting the particles float on the surface of a shallow water layer, which allows a study of the more detailed nature of the shear-jammed states and the transition from an unjammed state to a shear-jammed state. In this study, we also use high-precision force sensors to monitor the dynamical changes near the jamming transition. We further combine numerical simulations with the experiments to diagnose the nature of this jamming transition and its possible dependence on certain particle properties. The work at SJTU is in collaboration with Ling Zhang and Jie Zheng. The numerical simulations are in collaboration with Maobin Hu at Univ. of Sci. & Tech. of China.

  19. Measuring the constitutive behavior of viscoelastic solids in the time and frequency domain using flat punch nanoindentation

    SciTech Connect

    Herbert, E. G.; Oliver, W. C.; Lumsdaine, A.; Pharr, George Mathews

    2009-01-01

    The purpose of this work is to further develop experimental methodologies using flat punch nanoindentation to measure the constitutive behavior of viscoelastic solids in the frequency and time domain. The reference material used in this investigation is highly plasticized polyvinylchloride (PVC) with a glass transition temperature of -17 C. The nanoindentation experiments were conducted using a 983-{micro}m-diameter flat punch. For comparative purposes, the storage and loss modulus obtained by nanoindentation with a 103-{micro}m-diameter flat punch and dynamic mechanical analysis are also presented. Over the frequency range of 0.01-50 Hz, the storage and loss modulus measured using nanoindentation and uniaxial compression is shown to be in excellent agreement. The creep compliance function measured using a constant stress test performed in uniaxial compression and flat punch nanoindentation is also shown to correlate well over nearly 4 decades in time. In addition, the creep compliance function predicted from nanoindentation data acquired in the frequency domain is shown to correlate strongly with the creep compliance function measured in the time domain. Time-temperature superposition of nanoindentation data taken at 5, 10, 15, and 22 C shows the sample is not thermorheologically simple, and thus the technique cannot be used to expand the mechanical characterization of this material. Collectively, these results clearly demonstrate the ability of flat punch nanoindentation to accurately and precisely determine the constitutive behavior of viscoelastic solids in the time and frequency domain.

  20. The paper punched disc technique for lead in blood samples with abnormal haemoglobin values.

    PubMed Central

    Carter, G F

    1978-01-01

    A series of 15 blood samples with haemoglobin levels ranging from 4-6--16-1 g/dl were spotted on to Whatman No. 4 filter paper. Blood samples with low haemoglobin concentrations spread over a greater area of the filter paper than did those with high haemoglobin concentrations. This was further investigated by studying the performance of laboratory-prepared samples, and any effect on the estimation of blood lead value. Blood lead values assayed by the punched disc method on blood samples with low haemoglobin values were unreliable unless the estimated value was adjusted with respect to the area over which the blood had spread. Images PMID:698139

  1. Shearing stability of lubricants

    NASA Technical Reports Server (NTRS)

    Shiba, Y.; Gijyutsu, G.

    1984-01-01

    Shearing stabilities of lubricating oils containing a high mol. wt. polymer as a viscosity index improver were studied by use of ultrasound. The oils were degraded by cavitation and the degradation generally followed first order kinetics with the rate of degradation increasing with the intensity of the ultrasonic irradiation and the cumulative energy applied. The shear stability was mainly affected by the mol. wt. of the polymer additive and could be determined in a short time by mechanical shearing with ultrasound.

  2. TURBULENT SHEAR ACCELERATION

    SciTech Connect

    Ohira, Yutaka

    2013-04-10

    We consider particle acceleration by large-scale incompressible turbulence with a length scale larger than the particle mean free path. We derive an ensemble-averaged transport equation of energetic charged particles from an extended transport equation that contains the shear acceleration. The ensemble-averaged transport equation describes particle acceleration by incompressible turbulence (turbulent shear acceleration). We find that for Kolmogorov turbulence, the turbulent shear acceleration becomes important on small scales. Moreover, using Monte Carlo simulations, we confirm that the ensemble-averaged transport equation describes the turbulent shear acceleration.

  3. Shear Thinning in Xenon

    NASA Technical Reports Server (NTRS)

    Bergm Robert F.; Moldover, Michael R.; Yao, Minwu; Zimmerli, Gregory A.

    2009-01-01

    We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids such as molten plastics or ketchup, near the critical point of xenon. The data span a wide range of dimensionless shear rate: the product of the shear rate and the relaxation time of critical fluctuations was greater than 0.001 and was less than 700. As predicted by theory, shear thinning occurred when this product was greater than 1. The measurements were conducted aboard the Space Shuttle Columbia to avoid the density stratification caused by Earth's gravity.

  4. Time-dependent rheological behavior of natural polysaccharide xanthan gum solutions in interrupted shear and step-incremental/reductional shear flow fields

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Seok; Song, Ki-Won

    2015-11-01

    The objective of the present study is to systematically elucidate the time-dependent rheological behavior of concentrated xanthan gum systems in complicated step-shear flow fields. Using a strain-controlled rheometer (ARES), step-shear flow behaviors of a concentrated xanthan gum model solution have been experimentally investigated in interrupted shear flow fields with a various combination of different shear rates, shearing times and rest times, and step-incremental and step-reductional shear flow fields with various shearing times. The main findings obtained from this study are summarized as follows. (i) In interrupted shear flow fields, the shear stress is sharply increased until reaching the maximum stress at an initial stage of shearing times, and then a stress decay towards a steady state is observed as the shearing time is increased in both start-up shear flow fields. The shear stress is suddenly decreased immediately after the imposed shear rate is stopped, and then slowly decayed during the period of a rest time. (ii) As an increase in rest time, the difference in the maximum stress values between the two start-up shear flow fields is decreased whereas the shearing time exerts a slight influence on this behavior. (iii) In step-incremental shear flow fields, after passing through the maximum stress, structural destruction causes a stress decay behavior towards a steady state as an increase in shearing time in each step shear flow region. The time needed to reach the maximum stress value is shortened as an increase in step-increased shear rate. (iv) In step-reductional shear flow fields, after passing through the minimum stress, structural recovery induces a stress growth behavior towards an equilibrium state as an increase in shearing time in each step shear flow region. The time needed to reach the minimum stress value is lengthened as a decrease in step-decreased shear rate.

  5. Enhancing aspergiolide A production from a shear-sensitive and easy-foaming marine-derived filamentous fungus Aspergillus glaucus by oxygen carrier addition and impeller combination in a bioreactor.

    PubMed

    Cai, Menghao; Zhou, Xiangshan; Lu, Jian; Fan, Weimin; Niu, Chuanpeng; Zhou, Jiushun; Sun, Xueqian; Kang, Li; Zhang, Yuanxing

    2011-02-01

    Production enhancement of a novel antitumor compound aspergiolide A from shear-sensitive and easy-foaming marine-derived fungus Aspergillus glaucus HB1-19 in a 5-l stirred bioreactor was investigated. Two types of impellers, i.e., six-flat-blade disc turbine impeller (DT) and three-sector-blade pitched blade turbine impeller (PB) were used in this work. In cultures with fermentation medium, the combination of upper PB and lower DT led to the maximum dry biomass (13.8 g/l) and aspergiolide A production (19.3 mg/l). However, two PBs brought the highest aspergiolide A yield coefficient (1.9 mg/g dry biomass) despite it produced the lowest dry biomass (5.3 g/l). By contrast, two DTs and the upper DT and lower PB showed insignificant results. Feeding 0.35% (v/v) n-dodecane in cultures with upper PB and lower DT further improved aspergiolide A production by 31.0%, i.e., 25.3 mg/l, which is also 322% higher than that in the ordinary cultures with two DTs. PMID:21074418

  6. Paraprofessional Punch.

    ERIC Educational Resources Information Center

    Konkel, Mary S.

    This paper presents an outline for a plan for increasing OCLC cataloging statistics in the monograph cataloging unit of a medium-to-large academic library, along with the evaluation process used to achieve this goal. The focus of the plan was on a group of upper level paraprofessional staff. First, OCLC cooperative cataloging was redefined to…

  7. Punch List

    ERIC Educational Resources Information Center

    Biemiller, Lawrence

    2008-01-01

    This article features university architect Ron McCoy and describes his work at the Arizona State University (ASU). McCoy, now on his fifth year of overseeing construction on all four Arizona State campuses, came to ASU 14 years ago as a professor and director of the School of Architecture and Landscape Architecture. He was thinking seriously about…

  8. Predicting punching acceleration from selected strength and power variables in elite karate athletes: a multiple regression analysis.

    PubMed

    Loturco, Irineu; Artioli, Guilherme Giannini; Kobal, Ronaldo; Gil, Saulo; Franchini, Emerson

    2014-07-01

    This study investigated the relationship between punching acceleration and selected strength and power variables in 19 professional karate athletes from the Brazilian National Team (9 men and 10 women; age, 23 ± 3 years; height, 1.71 ± 0.09 m; and body mass [BM], 67.34 ± 13.44 kg). Punching acceleration was assessed under 4 different conditions in a randomized order: (a) fixed distance aiming to attain maximum speed (FS), (b) fixed distance aiming to attain maximum impact (FI), (c) self-selected distance aiming to attain maximum speed, and (d) self-selected distance aiming to attain maximum impact. The selected strength and power variables were as follows: maximal dynamic strength in bench press and squat-machine, squat and countermovement jump height, mean propulsive power in bench throw and jump squat, and mean propulsive velocity in jump squat with 40% of BM. Upper- and lower-body power and maximal dynamic strength variables were positively correlated to punch acceleration in all conditions. Multiple regression analysis also revealed predictive variables: relative mean propulsive power in squat jump (W·kg-1), and maximal dynamic strength 1 repetition maximum in both bench press and squat-machine exercises. An impact-oriented instruction and a self-selected distance to start the movement seem to be crucial to reach the highest acceleration during punching execution. This investigation, while demonstrating strong correlations between punching acceleration and strength-power variables, also provides important information for coaches, especially for designing better training strategies to improve punching speed. PMID:24276310

  9. Endonasal endoscopic dacryocystorhinostomy: how to achieve optimal results with simple punch technique.

    PubMed

    Naraghi, Mohsen; Tabatabaii Mohammadi, Sayed Ziaeddin; Sontou, Alain Fabrice; Farajzadeh Deroee, Armin; Boroojerdi, Masoud

    2012-05-01

    Endonasal endoscopic dacryocystorhinostomy (EEDCR) has been popularized as a minimally invasive technique. Although preliminary reports revealed less success in comparison with external approaches, recent endonasal endoscopic surgeries on various types of DCR have preserved advantages of this technique while diminishing the failures. We described our experience on EEDCR, including the main advantages and disadvantages of it. Hundred consecutive cases of lachrymal problems underwent EEDCR utilizing simple punch removal of bone, instead of powered instrumentation or lasers. The medial aspect of the sac was removed in all of patients, while preserving normal mucosa around the sac. Hundred cases of EEDCR were performed on 81 patients, with 19 bilateral procedures. Nine procedures were performed under local anesthesia. Based on a mean 14 months follow-up, 95 cases were free of symptoms, revealing 95% success rate. The punch technique diminishes the expenses of powered or laser instrumentation with comparable results. It seems that preserving normal tissues and creating a patent rhinostomy with least surgical trauma and less subsequent scar, plays the most important role in achieving desirable results. PMID:22065173

  10. Fretting contact of a functionally graded piezoelectric layered half-plane under a conducting punch

    NASA Astrophysics Data System (ADS)

    Su, Jie; Ke, Liao-Liang; Wang, Yue-Sheng

    2016-02-01

    This paper investigates the fretting contact between a functionally graded piezoelectric layered half-plane and a rigid cylindrical punch. The electro-elastic properties of functionally graded piezoelectric materials (FGPMs) vary exponentially along the thickness direction. It is assumed that the punch is a perfect conductor with a constant electric potential within the contact region. The two bodies are brought into contact first by a monotonically increasing normal load, and then by a cyclic tangential load which is less than that necessary to cause complete sliding. The whole contact region is composed of an inner stick region and two outer slip regions in which Coulomb’s friction law is assumed. The problem is reduced to a set of coupled Cauchy singular integral equations by using the Fourier integral transform technique and the superposition theorem. An iterative method is used to determine the unknown stick/slip region, normal contact pressure, electric charge and tangential traction. The effects of the resultant electric charge and gradient index on the surface electromechanical fields are discussed during different loading phases. It is found that FGPMs could potentially be applied to improve fretting contact damage in smart devices.

  11. Optimal design of a main driving mechanism for servo punch press based on performance atlases

    NASA Astrophysics Data System (ADS)

    Zhou, Yanhua; Xie, Fugui; Liu, Xinjun

    2013-09-01

    The servomotor drive turret punch press is attracting more attentions and being developed more intensively due to the advantages of high speed, high accuracy, high flexibility, high productivity, low noise, cleaning and energy saving. To effectively improve the performance and lower the cost, it is necessary to develop new mechanisms and establish corresponding optimal design method with uniform performance indices. A new patented main driving mechanism and a new optimal design method are proposed. In the optimal design, the performance indices, i.e., the local motion/force transmission indices ITI, OTI, good transmission workspace good transmission workspace(GTW) and the global transmission indices GTIs are defined. The non-dimensional normalization method is used to get all feasible solutions in dimensional synthesis. Thereafter, the performance atlases, which can present all possible design solutions, are depicted. As a result, the feasible solution of the mechanism with good motion/force transmission performance is obtained. And the solution can be flexibly adjusted by designer according to the practical design requirements. The proposed mechanism is original, and the presented design method provides a feasible solution to the optimal design of the main driving mechanism for servo punch press.

  12. Shear flexibility for structures

    NASA Technical Reports Server (NTRS)

    Stangeland, Maynard L. (Inventor)

    1976-01-01

    This device comprises a flexible sheet member having cross convolutions oriented 45.degree. to the shear vector with spherical reliefs at the convolution junctions. The spherical reliefs are essential to the shear flexibility by interrupting the principal stress lines that act along the ridges of the convolutions. The spherical reliefs provide convolutions in both directions in the plane of the cross-convolution ridges.

  13. Shear flexibility for structures

    NASA Technical Reports Server (NTRS)

    Stangeland, Maynard L. (Inventor)

    1977-01-01

    This device comprises a flexible sheet member having cross convolutions oriented 45.degree. to the shear vector with spherical reliefs at the convolution junctions. The spherical reliefs are essential to the shear flexibility by interrupting the principal stress lines that act along the ridges of the convolutions. The spherical reliefs provide convolutions in both directions in the plane of the cross-convolution ridges.

  14. Fighting wind shear

    NASA Astrophysics Data System (ADS)

    A “coherent and sustained program” of improved radar detection of weather, pilot training, and better communication between pilots and air controllers can greatly reduce the risk of wind shear to airplanes landing or taking off, according to a National Research Council (NRC) committee.Wind shear, characterized by winds rapidly changing direction and speed, has caused several serious accidents in recent years; among the most notable is the July 8, 1982, crash of a Pan American World Airlines jetliner at the New Orleans International Airport, which killed 153 persons. Following the accident, Congress directed the Federal Aviation Administration (FAA) to contract with the NRC to study wind shear.

  15. Fan-structure waves in shear ruptures

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris

    2016-04-01

    This presentation introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new slabs), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the correspondingly low transient strength of the lithosphere, which favours generation of new earthquake faults in the intact rock mass adjoining pre-existing faults in preference to frictional stick-slip instability along these faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created, while further dynamic propagation of the new fault (earthquake) occurs at low field stresses even below the frictional strength.

  16. Viscous shear dampers

    SciTech Connect

    Zilahi-Szabo, I.

    1980-10-07

    In a viscous shear damper, the seismic mass is chamfered at all its corners. Thus, the clearances between the seismic mass and its casing are gaps with oppositely widening out sections separated by middle sections of smallest widths.

  17. Isolation of high quality protein samples from punches of formalin fixed and paraffin embedded tissue blocks.

    PubMed

    Kroll, J; Becker, K F; Kuphal, S; Hein, R; Hofstädter, F; Bosserhoff, A K

    2008-04-01

    In general, it is believed that the extraction of proteins from formalin-fixed paraffin embedded samples is not feasible. However, recently a new technique was developed, presenting the extraction of non-degraded, full length proteins from formalin fixed tissues, usable for western blotting and protein arrays. In the study presented here, we applied this technique to punch biopsies of formalin fixed tissues embedded in paraffin to reduce heterogeneity of the tissue represented in sections, and to ensure analysing mainly defined cellular material. Successful extraction was achieved even from very small samples (0.7 mm(3)). Additionally, we were able to detect highly glycosylated proteins and protein modification, such as phosphorylation. Interestingly, with this technique it is feasible to extract high quality proteins from 14 year old samples. In summary, the new technique makes a great pool of material now usable for molecular analysis with high throughput tools. PMID:18228195

  18. High-temperature strength analysis of welded joint of RAFs by small punch test

    NASA Astrophysics Data System (ADS)

    Kato, Taichiro; Komazaki, Shin-ichi; Kohno, Yutaka; Tanigawa, Hiroyasu; Kohyama, Akira

    2009-04-01

    Type IV creep damage has recently been a worldwide issue for high Cr ferritic steels. The small punch (SP) creep test has been successfully applied to evaluate this damage of low alloy ferritic steel by the author's group. However, the heat affected zone (HAZ) of fusion reactor material welded by electron-beam (EB) welding is so thin that it is not easy to evaluate its mechanical properties by the conventional SP test. In this study, the SP test using a further miniaturized specimen was applied to the EB welded joint of reduced activation ferritic steel (RAFs), for evaluating high-temperature tensile properties of the HAZs. As the result, the σy and σB of the tempered HAZ at 873 K were estimated to be as low as 275-300 MPa and 325-340 MPa, respectively.

  19. Galenic approaches in troubleshooting of glibenclamide tablet adhesion in compression machine punches

    PubMed Central

    Boniatti, Janine; Pereira Cerqueira, Ana Lúcia; de Souza, Alexandre Carnevale; Drago Hoffmeister, Cristiane Rodrigues; da Costa, Maira Assis; Prado, Livia Deris; Tasso, Leandro; Antunes Rocha, Helvécio Vinícius

    2013-01-01

    This study aimed to examine the adhesion of glibenclamide 5 mg tablets to the tools of compression machines. This problem is not commonly reported in the literature, since it is considered as tacit knowledge. The starting point was the implementation of three technical alternatives: changing the parameters of compression, evaluating the humidity of the powder blend and the manufacturer of the lubricant magnesium stearate. The adhesion was directly related to the characteristics of magnesium stearate from different manufacturers, and the feasibility of evaluating powder flow characteristics by different techniques that are not routinely followed in various pharmaceutical companies. In vitro dissolution tests showed that the magnesium stearate manufacturer can influence on the dissolution profile of glibenclamide tablets. This study presented various aspects of tablet adhesion to compression machine punches. Troubleshooting approaches can be, most of times, conducted based on previous experience, or an experimental research needs to be implemented in order to have confident results. PMID:25473333

  20. Punch stretching process monitoring using acoustic emission signal analysis. II - Application of frequency domain deconvolution

    NASA Technical Reports Server (NTRS)

    Liang, Steven Y.; Dornfeld, David A.; Nickerson, Jackson A.

    1987-01-01

    The coloring effect on the acoustic emission signal due to the frequency response of the data acquisition/processing instrumentation may bias the interpretation of AE signal characteristics. In this paper, a frequency domain deconvolution technique, which involves the identification of the instrumentation transfer functions and multiplication of the AE signal spectrum by the inverse of these system functions, has been carried out. In this way, the change in AE signal characteristics can be better interpreted as the result of the change in only the states of the process. Punch stretching process was used as an example to demonstrate the application of the technique. Results showed that, through the deconvolution, the frequency characteristics of AE signals generated during the stretching became more distinctive and can be more effectively used as tools for process monitoring.

  1. Contact Problem Of Conducting And Heated Punch On A Multifield Foundation

    NASA Astrophysics Data System (ADS)

    Rogowski, B.

    2015-08-01

    The solution for a multifield material subjected to temperature loading in a circular region is presented in an explicit analytical form. The study concerns the steady - state thermal loading infinite region (heated embedded inclusion), half - space region and two - constituent magneto - electro - thermo - elastic material region. The new mono - harmonic potential functions, obtained by the author, are used in the analysis of punch problem. The more interested case in which the contact region is annular is analyzed. By using the methods of triple integral equations and series solution technique the solution for an indentured multifield substrate over an annular contact region is given. The sensitivity analysis of obtained indentation parameters shows some interesting points. In particular, it shows that the increasing of the applied electric and magnetic potentials reduces the indentation depth in multifield materials.

  2. Stress intensity factors in a cracked infinite elastic wedge loaded by a rigid punch

    NASA Technical Reports Server (NTRS)

    Erdogan, F.; Civelek, M. B.

    1978-01-01

    A plane elastic wedge-shaped solid was split through the application of a rigid punch. It was assumed that the coefficient of friction on the the contact area was constant, and the problem had a plane of symmetry with respect to loading and geometry, with the crack in the plane of symmetry. The problem was formulated in terms of a system of integral equations with the contact stress and the derivative of the crack surface displacement as the unknown functions. The solution was obtained for an internal crack and for an edge crack. The results include primarily the stress intensity factors at the crack tips, and the measure of the stress singularity at the wedge apex, and at the end points of the contact area.

  3. Methanogenic Activity and Structural Characteristics of the Microbial Biofilm On a Needle-Punched Polyester Support

    PubMed Central

    Harvey, Martin; Forsberg, Cecil W.; Beveridge, Terry J.; Pos, Jack; Ogilvie, John R.

    1984-01-01

    In a downflow stationary fixed-film anaerobic reactor receiving a swine waste influent, few bacteria were observed to be tightly adherent to the surfaces of the needle-punched polyester support material. However, there was a morphologically complex, dense population of bacteria trapped within the matrix. Frequently large microcolonies of a uniform morphological type of bacteria were observed. These were particularly evident for methanosarcina-like bacteria which grew forming large aggregates of unseparated cells. Leafy deposits of electron-dense, calcium- and phosphorus-enriched material coated the polyester matrix and some cells. As the biofilm matured there was more extensive mineral deposition which completely entrapped cells. The entrapped cells appeared to autolyze, and many were partially degraded. Further impregnation of the matrix with minerals and apparent cell death may eventually have a deleterious effect on the methanogenic activity of the biofilm. Images PMID:16346629

  4. Galenic approaches in troubleshooting of glibenclamide tablet adhesion in compression machine punches.

    PubMed

    Boniatti, Janine; Pereira Cerqueira, Ana Lúcia; de Souza, Alexandre Carnevale; Drago Hoffmeister, Cristiane Rodrigues; da Costa, Maira Assis; Prado, Livia Deris; Tasso, Leandro; Antunes Rocha, Helvécio Vinícius

    2014-11-01

    This study aimed to examine the adhesion of glibenclamide 5 mg tablets to the tools of compression machines. This problem is not commonly reported in the literature, since it is considered as tacit knowledge. The starting point was the implementation of three technical alternatives: changing the parameters of compression, evaluating the humidity of the powder blend and the manufacturer of the lubricant magnesium stearate. The adhesion was directly related to the characteristics of magnesium stearate from different manufacturers, and the feasibility of evaluating powder flow characteristics by different techniques that are not routinely followed in various pharmaceutical companies. In vitro dissolution tests showed that the magnesium stearate manufacturer can influence on the dissolution profile of glibenclamide tablets. This study presented various aspects of tablet adhesion to compression machine punches. Troubleshooting approaches can be, most of times, conducted based on previous experience, or an experimental research needs to be implemented in order to have confident results. PMID:25473333

  5. Fracture toughness evaluation of fusion reactor structural steels at low temperatures by small punch tests

    NASA Astrophysics Data System (ADS)

    Misawa, T.; Nagata, S.; Aoki, N.; Ishizaka, J.; Hamaguchi, Y.

    1989-12-01

    A small punch (SP) test using miniaturized specimens has been performed for cryogenic austenitic steels at 4.2, 77 and 293 K to evaluate fracture toughness in a fusion material program. An SP testing cryostat for load versus deflection curve measurements has been successfully constructed. A universal relationship between valid fracture toughness, JIC, and equivalent fracture strain, ¯ge qf, for austenitic steels at different test temperatures has been confirmed and empirical parameters for that relation have been determined using a linear regression model. A linear correlation between valid JIC and ¯ge qf has been clarified for austenitic steels at low temperatures, where the regression coefficient is found to be 845 kJ/m 2. Using the results of the SP test above room temperature, a new attempt at statistical analysis has been proposed to estimate the relative change in fracture toughness due to neutron irradiation.

  6. Contributions of different strengthening mechanisms to the shear strength of an extruded Mg-4Zn-0.5Ca alloy

    NASA Astrophysics Data System (ADS)

    Naghdi, F.; Mahmudi, R.; Kang, J. Y.; Kim, H. S.

    2015-11-01

    The shear deformation behaviour of an extruded Mg-4Zn-0.5Ca alloy was studied using shear punch testing at room temperature. The extrusion process effectively refined the microstructure, leading to a grain size of 4.6 ± 1.4 μm. Contributions of different strengthening mechanisms to the room temperature shear yield stress, and overall flow stress of the material, were calculated. These mechanisms include dislocation strengthening, grain boundary strengthening, solid solution hardening and strengthening resulting from second-phase particles. Grain boundary strengthening and solid solution hardening made significant contributions to the overall strength of the material, while the contributions of second-phase particles and dislocations were trivial. The observed differences between calculated and experimental strength values were discussed based on the textural softening of the material.

  7. Tissue Microarray Technology for Molecular Applications: Investigation of Cross-Contamination between Tissue Samples Obtained from the Same Punching Device

    PubMed Central

    Vassella, Erik; Galván, José A.; Zlobec, Inti

    2015-01-01

    Background: Tissue microarray (TMA) technology allows rapid visualization of molecular markers by immunohistochemistry and in situ hybridization. In addition, TMA instrumentation has the potential to assist in other applications: punches taken from donor blocks can be placed directly into tubes and used for nucleic acid analysis by PCR approaches. However, the question of possible cross-contamination between samples punched with the same device has frequently been raised but never addressed. Methods: Two experiments were performed. (1) A block from mycobacterium tuberculosis (TB) positivetissue and a second from an uninfected patient were aligned side-by-side in an automated tissue microarrayer. Four 0.6 mm punches were cored from each sample and placed inside their corresponding tube. Between coring of each donor block, a mechanical cleaning step was performed by insertion of the puncher into a paraffin block. This sequence of coring and cleaning was repeated three times, alternating between positive and negative blocks. A fragment from the 6110 insertion sequence specific for mycobacterium tuberculosis was analyzed; (2) Four 0.6 mm punches were cored from three KRAS mutated colorectal cancer blocks, alternating with three different wild-type tissues using the same TMA instrument (sequence of coring: G12D, WT, G12V, WT, G13D and WT). Mechanical cleaning of the device between each donor block was made. Mutation analysis by pyrosequencing was carried out. This sequence of coring was repeated manually without any cleaning step between blocks. Results/Discussion: In both analyses, all alternating samples showed the expected result (samples 1, 3 and 5: positive or mutated, samples 2, 4 and 6: negative or wild-type). Similar results were obtained without cleaning step. These findings suggest that no cross-contamination of tissue samples occurs when donor blocks are punched using the same device, however a cleaning step is nonetheless recommended. Our result supports

  8. Probing the shear-band formation in granular media with sound waves.

    PubMed

    Khidas, Y; Jia, X

    2012-05-01

    We investigate the mechanical responses of dense granular materials, using a direct shear box combined with simultaneous acoustic measurements. Measured shear wave speeds evidence the structural change of the material under shear, from the jammed state to the flowing state. There is a clear acoustic signature when the shear band is formed. Subjected to cyclic shear, both shear stress and wave speed show the strong hysteretic dependence on the shear strain, likely associated with the geometry change in the packing structure. Moreover, the correlation function of configuration-specific multiply scattered waves reveals an intermittent behavior before the failure of material. PMID:23004745

  9. Study on the effect of punched holes on flow structure and heat transfer of the plain fin with multi-row delta winglets

    NASA Astrophysics Data System (ADS)

    Tian, Liting; Liu, Bin; Min, Chunhua; Wang, Jin; He, Yaling

    2015-11-01

    Three dimensional numerical simulations are performed to investigate the flow and heat transfer characteristics of the plain fin with multi-row delta winglets punched out from the fin. The Reynolds number based on the tube outside diameter varies from 360 to 1440. The effects of punched holes and their orientations on flow structure and heat transfer are numerically studied. Results show that a down-wash flow is formed through the hole punched at the windward side, which has little influence on the longitudinal vortices in the main flow, and a longitudinal main vortex is formed behind each delta winglet. An up-wash flow is formed through the hole punched at the leeward side, the up-wash flow impinges the longitudinal vortices generated by the delta winglet, and then a counter-rotating pair of main vortices is generated behind each delta winglet. The windward punched holes have little effect on the flow friction and heat transfer of the plain fin with delta winglets, while the leeward punched holes deteriorate the heat transfer and decrease the flow friction of the fin channel, the Nusselt number decreases by 3.5-5.0 % with a corresponding decrease of 3.9-4.8 % in the friction factor. The effect of the punched holes on the heat transfer of the fin can be well explained by the field synergy principle. The overall analysis of the thermal performance is performed for all fin configurations, including the slit fins and the wavy fins with one-row delta winglets, the plain fin with the windward punched delta winglets shows the better thermal performance than one with the leeward punched delta winglets.

  10. Converging shear rheometer

    NASA Astrophysics Data System (ADS)

    Baek, Hyung M.; Mix, Adam W.; Giacomin, A. Jeffrey

    2014-05-01

    For highly viscous fluids that slip in parallel sliding plate rheometers, we want to use a slightly converging flow to suppress this wall slip. In this work, we first attack the steady shear flow of a highly viscous Newtonian fluid between two gently converging plates with no slip boundaries using the equation of motion in cylindrical coordinates, which yields no analytical solution. Then we treat the same problem using the lubrication approximation in Cartesian coordinates to yield exact, explicit solutions for dimensionless velocity, pressure and shear stress. This work deepens our understanding of a drag flow through a gently converging slit of arbitrary convergence angle. We also employ the corotational Maxwell model to explore the role of viscoelasticity in this converging shear flow. We then compare these analytical solutions to finite element calculations for both Newtonian and corotational Maxwell cases. A worked example for determining the Newtonian viscosity using a converging shear rheometer is also included. With this work, we provide the framework for exploring other constitutive equations or other boundary conditions in future work. Our results can also be used to design the linear bearings used for the parallel sliding plate rheometer (SPR). This work can also be used to evaluate the error in the shear stress that is caused by bearing misalignment and specify the parallelism tolerance for the linear bearings incorporated into a SPR.

  11. Free volume under shear.

    PubMed

    Maiti, Moumita; Vinutha, H A; Sastry, Srikanth; Heussinger, Claus

    2015-10-14

    Using an athermal quasistatic simulation protocol, we study the distribution of free volumes in sheared hard-particle packings close to, but below, the random-close packing threshold. We show that under shear, and independent of volume fraction, the free volumes develop features similar to close-packed systems - particles self-organize in a manner as to mimick the isotropically jammed state. We compare athermally sheared packings with thermalized packings and show that thermalization leads to an erasure of these structural features. The temporal evolution in particular the opening-up and the closing of free-volume patches is associated with the single-particle dynamics, showing a crossover from ballistic to diffusive behavior. PMID:26472384

  12. Combined method of compaction of collapsible soils

    SciTech Connect

    Bagdasarov, Yu.A.

    1994-07-01

    The writer proposes a combined method of compaction of collapsible soils. He presents results of investigations carried out to study compacted zones of pads punched (tamped-out) by rammers 10 and 20 tons in mass, as well as a comparative analysis of the pads over against compacted zones obtained by means of plane rammers. The analysis results are illustrated by the {open_quotes}arch effect{close_quotes} on the stress conditions of the soaked soil mass.

  13. Metal shearing energy absorber

    NASA Technical Reports Server (NTRS)

    Fay, R. J.; Wittrock, E. P. (Inventor)

    1973-01-01

    A metal shearing energy absorber is described. The absorber is composed of a flat thin strip of metal which is pulled through a slot in a cutter member of a metal, harder than the metal of the strip. The slot's length, in the direction perpendicular to the pull direction, is less than the strip's width so that as the strip is pulled through the slot, its edges are sheared off, thereby absorbing some of the pulling energy. In one embodiment the cutter member is a flat plate of steel, while in another embodiment the cutter member is U-shaped with the slot at its base.

  14. Ultrasonic shear wave couplant

    DOEpatents

    Kupperman, D.S.; Lanham, R.N.

    1984-04-11

    Ultrasonically testing of an article at high temperatures is accomplished by the use of a compact layer of a dry ceramic powder as a couplant in a method which involves providing an ultrasonic transducer as a probe capable of transmitting shear waves, coupling the probe to the article through a thin compact layer of a dry ceramic powder, propagating a shear wave from the probe through the ceramic powder and into the article to develop echo signals, and analyzing the echo signals to determine at least one physical characteristic of the article.

  15. Ultrasonic shear wave couplant

    DOEpatents

    Kupperman, David S.; Lanham, Ronald N.

    1985-01-01

    Ultrasonically testing of an article at high temperatures is accomplished by the use of a compact layer of a dry ceramic powder as a couplant in a method which involves providing an ultrasonic transducer as a probe capable of transmitting shear waves, coupling the probe to the article through a thin compact layer of a dry ceramic powder, propagating a shear wave from the probe through the ceramic powder and into the article to develop echo signals, and analyzing the echo signals to determine at least one physical characteristic of the article.

  16. Infrared lateral shearing interferometers

    NASA Astrophysics Data System (ADS)

    Kwon, O.

    1980-04-01

    Recently IR interferometry has received much attention for its special capabilities of testing IR materials, diamond-turned metal mirrors, deep aspherics, unpolished rough surface optics, and other unconventional optics. A CW CO2 laser is used as a coherent light source at 10.6 microns, and germanium and zinc selenide optics are used for lenses and beam splitters. A pyroelectric vidicon (PEV) detects the modulated interference pattern through a TV monitor and video recorder-player. This paper presents three methods of IR lateral shear interferometry using (1) a germanium plane-parallel plate, (2) a Ronchi ruling, and (3) a double-grating lateral shear interferometer.

  17. Shear-flow Effects in Open Traps

    SciTech Connect

    Beklemishev, A. D.

    2008-11-01

    Interaction between shear flows and plasma instabilities and turbulence in open traps can lead to improved confinement both in experiments and in simulations. Shear flows, driven by biasing end-plates and limiters or by off-axis electron heating, in combination with the finite-larmor-radius (FLR) effects are shown to be efficient in confining plasmas even with unstable flute modes. Interpretation of the observed effects as the ''vortex confinement,'' i.e., confinement of the plasma core in the dead-flow zone of the driven vortex, is shown to agree well with simulations.

  18. Shear wave transmissivity measurement by color Doppler shear wave imaging

    NASA Astrophysics Data System (ADS)

    Yamakoshi, Yoshiki; Yamazaki, Mayuko; Kasahara, Toshihiro; Sunaguchi, Naoki; Yuminaka, Yasushi

    2016-07-01

    Shear wave elastography is a useful method for evaluating tissue stiffness. We have proposed a novel shear wave imaging method (color Doppler shear wave imaging: CD SWI), which utilizes a signal processing unit in ultrasound color flow imaging in order to detect the shear wave wavefront in real time. Shear wave velocity is adopted to characterize tissue stiffness; however, it is difficult to measure tissue stiffness with high spatial resolution because of the artifact produced by shear wave diffraction. Spatial average processing in the image reconstruction method also degrades the spatial resolution. In this paper, we propose a novel measurement method for the shear wave transmissivity of a tissue boundary. Shear wave wavefront maps are acquired by changing the displacement amplitude of the shear wave and the transmissivity of the shear wave, which gives the difference in shear wave velocity between two mediums separated by the boundary, is measured from the ratio of two threshold voltages required to form the shear wave wavefronts in the two mediums. From this method, a high-resolution shear wave amplitude imaging method that reconstructs a tissue boundary is proposed.

  19. From micro- to nano-scale molding of metals : size effect during molding of single crystal Al with rectangular strip punches.

    SciTech Connect

    Chen, K.; Meng, W. J.; Mei, F.; Hiller, J.; Miller, D. J.

    2011-02-01

    A single crystal Al specimen was molded at room temperature with long, rectangular, strip diamond punches. Quantitative molding response curves were obtained at a series of punch widths, ranging from 5 {micro}m to 550 nm. A significant size effect was observed, manifesting itself in terms of significantly increasing characteristic molding pressure as the punch width decreases to 1.5 {micro}m and below. A detailed comparison of the present strip punch molding results was made with Berkovich pyramidal indentation on the same single crystal Al specimen. The comparison reveals distinctly different dependence of the characteristic pressure on corresponding characteristic length. The present results show the feasibility of micro-/nano-scale compression molding as a micro-/nano-fabrication technique, and offer an experimental test case for size-dependent plasticity theories.

  20. A Study on Segmented Multiple-Step Forming of Doubly Curved Thick Plate by Reconfigurable Multi-Punch Dies

    SciTech Connect

    Ko, Young Ho; Han, Myoung Soo; Han, Jong Man

    2007-05-17

    Doubly curved thick plate forming in shipbuilding industries is currently performed by a thermal forming process, called as Line Heating by using gas flame torches. Due to the empirical manual work of it, the industries are eager for an alternative way to manufacture curved thick plates for ships. It was envisaged in this study to manufacture doubly curved thick plates by the multi-punch die forming. Experiments and finite element analyses were conducted to evaluate the feasibility of the reconfigurable discrete die forming to the thick plates. Single and segmented multiple step forming procedures were considered from both forming efficiency and accuracy. Configuration of the multi-punch dies suitable for the segmented multiple step forming was also explored. As a result, Segmented multiple step forming with matched dies had a limited formability when the objective shapes become complicate, while a unmatched die configuration provided better possibility to manufacture large curved plates for ships.

  1. Modified connective tissue punch technique to increase the vestibular/buccal keratinized tissue on flapless implant surgery: a case series.

    PubMed

    Andreasi Bassi, M; Andrisani, C; Lopez, M A; Gaudio, R M; Lombardo, L; Lauritano, D

    2016-01-01

    The aim of this article is to show a simple and predictable technique to enhance both the vestibular/buccal (V/B) gingival thickness (GT) and keratinized tissue width (KTW) improving the soft-tissue profile after flapless implant placement. The technique proposed was named Modified Connective Tissue Punch (MCTP). Fourteen patients (6 men and 8 women) aged between 35 and 69 years (mean value 48.07±13.023 years) were enrolled in this case series. Seventeen implant sites were submitted to flapless procedure. The connective punch (CP) was harvested with a motor-driven circular tissue punch and then a full-split dissection was executed, in order to create a deep pouch, beyond the mucogingival junction, on the V/B side. In this recipient site the CP was placed. The normal flapless surgical protocol was used; implants were inserted and covered with transgingival healing cap screws. GT and KTW were measured: both immediately before and after surgery; at the time of the prosthetic finalization (3-4months, respectively, for mandible and maxilla); 1 year post surgery follow-up. GT was measured at 1 mm, 2 mm and 5 mm on the V/B side, from the outline of the punch. Both KTW and GT at 1 and 2 mm can be effectively increased, while no significant effects for GT at 5 mm can be expected from this technique. Furthermore, the mean values of KTW and GT at 1 mm and 2 mm show significant increases at 3-4 months post-operative, while no further significant increments are shown at 1 year post-operative follow-up. The Authors recommend the use of the MCTP technique to reduce the number of aesthetic complications and soft tissue defects in flapless implant surgery. Longer follow-ups are needed to evaluate the stability of peri-implant tissues over time. PMID:27469545

  2. Small punch test evaluation of neutron-irradiation-induced embrittlement of a Cr-Mo low-alloy steel

    SciTech Connect

    Song, S.-H. . E-mail: shsonguk@yahoo.co.uk; Faulkner, R.G.; Flewitt, P.E.J.; Marmy, P.; Weng, L.-Q.

    2004-09-15

    Neutron-irradiation-induced embrittlement of a 2.25Cr1Mo steel is investigated by means of small punch testing along with scanning electron microscopy. There is an apparent irradiation-induced embrittlement effect after the steel is irradiated at about 400 deg. C for 86 days with a neutron dose rate of 1.75x10{sup -8} dpa/s. The embrittlement is mainly nonhardening embrittlement caused by impurity grain boundary segregation.

  3. Measuring the reduced shear

    SciTech Connect

    Zhang, Jun

    2011-11-01

    Neglecting the second order corrections in weak lensing measurements can lead to a few percent uncertainties on cosmic shears, and becomes more important for cluster lensing mass reconstructions. Existing methods which claim to measure the reduced shears are not necessarily accurate to the second order when a point spread function (PSF) is present. We show that the method of Zhang (2008) exactly measures the reduced shears at the second order level in the presence of PSF. A simple theorem is provided for further confirming our calculation, and for judging the accuracy of any shear measurement method at the second order based on its properties at the first order. The method of Zhang (2008) is well defined mathematically. It does not require assumptions on the morphologies of galaxies and the PSF. To reach a sub-percent level accuracy, the CCD pixel size is required to be not larger than 1/3 of the Full Width at Half Maximum (FWHM) of the PSF, regardless of whether the PSF has a power-law or exponential profile at large distances. Using a large ensemble (∼>10{sup 7}) of mock galaxies of unrestricted morphologies, we study the shear recovery accuracy under different noise conditions. We find that contaminations to the shear signals from the noise of background photons can be removed in a well defined way because they are not correlated with the source shapes. The residual shear measurement errors due to background noise are consistent with zero at the sub-percent level even when the amplitude of such noise reaches about 1/10 of the source flux within the half-light radius of the source. This limit can in principle be extended further with a larger galaxy ensemble in our simulations. On the other hand, the source Poisson noise remains to be a cause of systematic errors. For a sub-percent level accuracy, our method requires the amplitude of the source Poisson noise to be less than 1/80 ∼ 1/100 of the source flux within the half-light radius of the source

  4. Universality of the diffusion wake from stopped and punch-through jets in heavy-ion collisions

    SciTech Connect

    Betz, Barbara; Noronha, Jorge; Torrieri, Giorgio; Mishustin, Igor; Gyulassy, Miklos; Rischke, Dirk H.

    2009-03-15

    We solve (3+1)-dimensional ideal hydrodynamical equations with source terms that describe punch-through and fully stopped jets to compare their final away-side angular correlations in a static medium. For fully stopped jets, the backreaction of the medium is described by a simple Bethe-Bloch-like model that leads to an explosive burst of energy and momentum (Bragg peak) close to the end of the jet's evolution through the medium. Surprisingly enough, we find that the medium's response and the corresponding away-side angular correlations are largely insensitive to whether the jet punches through or stops inside the medium. This result is also independent of whether momentum deposition is longitudinal (as generally occurs in pQCD energy loss models) or transverse (as the Bethe-Bloch formula implies). The existence of the diffusion wake is therefore shown to be universal to all scenarios where momentum as well as energy is deposited into the medium, which can readily be understood in ideal hydrodynamics through vorticity conservation. The particle yield coming from the strong forward moving diffusion wake that is formed in the wake of both punch-through and stopped jets largely overwhelms their weak Mach cone signal after freeze-out.

  5. Universality of the diffusion wake from stopped and punch-through jets in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Betz, Barbara; Noronha, Jorge; Torrieri, Giorgio; Gyulassy, Miklos; Mishustin, Igor; Rischke, Dirk H.

    2009-03-01

    We solve (3+1)-dimensional ideal hydrodynamical equations with source terms that describe punch-through and fully stopped jets to compare their final away-side angular correlations in a static medium. For fully stopped jets, the backreaction of the medium is described by a simple Bethe-Bloch-like model that leads to an explosive burst of energy and momentum (Bragg peak) close to the end of the jet's evolution through the medium. Surprisingly enough, we find that the medium's response and the corresponding away-side angular correlations are largely insensitive to whether the jet punches through or stops inside the medium. This result is also independent of whether momentum deposition is longitudinal (as generally occurs in pQCD energy loss models) or transverse (as the Bethe-Bloch formula implies). The existence of the diffusion wake is therefore shown to be universal to all scenarios where momentum as well as energy is deposited into the medium, which can readily be understood in ideal hydrodynamics through vorticity conservation. The particle yield coming from the strong forward moving diffusion wake that is formed in the wake of both punch-through and stopped jets largely overwhelms their weak Mach cone signal after freeze-out.

  6. Depositing archived paraffin tissue core biopsy specimens in paraffin tissue microarrays using a paraffin tissue punch modified with a countersink

    PubMed Central

    Vogel, Ulrich Felix

    2007-01-01

    Paraffin tissue microarrays (PTMAs) introduced by Kononen et al in 1998 have become a widely used technique in routine pathology and even more so in research. Kononen used a tissue puncher/arrayer (Beecher Instruments, Sun Prairie, WI, USA) to take paraffin tissue core biopsy specimens (PTCBs) of 0.6–2 mm in diameter from routine paraffin tissue blocks and transfer them to another paraffin block with up to 1000 holes. As pointed out by Mengel et al, however, it is not possible to use the Kononen/Beecher system to construct PTMAs out of archived PTCBs. To overcome this drawback in the extremely popular Beecher system, the paraffin tissue punch was modified by incorporating a conical 4 mm deep countersink. This countersink was milled with a conical precision cutter that can be bought in an ordinary hardware store (cost punch and enables the construction of PTMAs with previously archived PTCBs using the widely distributed Beecher system. Moreover, this paraffin tissue punch can be used for other systems to create PTMAs, such as the low‐budget systems designed by Vogel. PMID:17079355

  7. On the correlation between minimum thickness and central deflection during small punch test

    NASA Astrophysics Data System (ADS)

    Kumar, Pradeep; Chattopadhyay, J.; Dutta, B. K.

    2016-07-01

    Present paper deals with a detailed study on the correlation between minimum thickness (t/t0) and central deflection (δ/t0). Such data are obtained during the deformation of a small punch test of miniaturized specimen. Finite element studies have been carried out to investigate the effect of various parameters which are expected to influence this correlation. The parameters under consideration are material hardening, material yield stress, coefficient of friction and initial thickness of the specimen. It is shown that the correlation remains unaffected with respect to change in material parameters. Similarly, the coefficient of friction beyond 0.2 also does not affect the correlation. However, change in thickness has significant effect on the correlation. A modification has been suggested in the existing correlation to consider the influence of thickness change. The modified correlation is then used to calculate fracture toughness using the experimental results quoted in the literature. It is shown that the modified correlation improves the fracture toughness prediction considerably.

  8. Study of Hot Tearing During Steel Solidification Through Ingot Punching Test and Its Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Koshikawa, Takao; Bellet, Michel; Gandin, Charles-André; Yamamura, Hideaki; Bobadilla, Manuel

    2016-06-01

    Experimental and numerical studies of hot tearing formation in steel are reported. On the one hand, an ingot punching test is presented. It consists in the application of a deformation at the surface of a solidifying 450 kg steel ingot. The experimental parameters are the displacement of the pressing tool, together with its velocity, leading to variations of a global strain rate. On the other hand, three-dimensional finite element thermomechanical modeling of the test is used. The time evolution of the strain tensor serves to compute an index to evaluate the susceptibility to create hot tears. It is based on the integration of a hot tearing criterion (HTC) that compares the local accumulation of strain with the expression of a critical value proposed in the literature. The main variable of the criterion is the brittleness temperature range (BTR) that refers to the solidification interval during which strain accumulates and creates hot cracks or tears. Detailed comparison of the simulation results with the measurements reveals the importance of the BTR for the prediction as well as excellent capabilities of the HTC to predict the formation of hot tears.

  9. Study of Hot Tearing During Steel Solidification Through Ingot Punching Test and Its Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Koshikawa, Takao; Bellet, Michel; Gandin, Charles-André; Yamamura, Hideaki; Bobadilla, Manuel

    2016-08-01

    Experimental and numerical studies of hot tearing formation in steel are reported. On the one hand, an ingot punching test is presented. It consists in the application of a deformation at the surface of a solidifying 450 kg steel ingot. The experimental parameters are the displacement of the pressing tool, together with its velocity, leading to variations of a global strain rate. On the other hand, three-dimensional finite element thermomechanical modeling of the test is used. The time evolution of the strain tensor serves to compute an index to evaluate the susceptibility to create hot tears. It is based on the integration of a hot tearing criterion (HTC) that compares the local accumulation of strain with the expression of a critical value proposed in the literature. The main variable of the criterion is the brittleness temperature range (BTR) that refers to the solidification interval during which strain accumulates and creates hot cracks or tears. Detailed comparison of the simulation results with the measurements reveals the importance of the BTR for the prediction as well as excellent capabilities of the HTC to predict the formation of hot tears.

  10. The tabletting machine as an analytical instrument: qualification of the tabletting machine and the instrumentation with respect to the determination of punch separation and validation of the calibration procedures.

    PubMed

    Belda, P M; Mielck, J B

    1999-05-01

    The quality of the determination of punch separation in an eccentric tabletting machine equipped with two inductive displacement transducers was carefully investigated, since this tabletting machine is used as an 'analytical instrument' for the evaluation of the compression behaviour of pharmaceutical materials. For a quasistatic calibration procedure using gauge blocks, the repeatability under standard conditions and the robustness against variations in machine settings, installation conditions, equipment and methods were examined. The readings during calibration can be easily influenced by machine parameters as a result of deficiencies in the construction of the machine and in the mode of instrumentation. The poor plane-parallelism of the punch faces has a further negative effect on the accuracy of punch separation. In addition, the response at loading to lower and higher forces as during calibration was investigated. While at loading up to 100 N, the response of the system to the gauge blocks is systematically influenced by punch separation, for slow manually applied punch-to-punch loading up to 16.5 kN at a broad range of penetration depths, no significant effects were observed in the region of interest for tabletting. To get an indication of the transferability of the calibration and the determination of punch deformation to normal operating conditions, the lateral tilting of the punches during dynamic idle runs, punch-to-punch loading, and compression of microcrystalline cellulose was analyzed. A transfer of the response derived from punch-to-punch compression to tabletting conditions seems to be possible, although this must be questioned on grounds of theoretical considerations. From all the experiments performed, a total error of about +/- 30 microns must be assessed for the determination of punch separation. PMID:10382107