Journal articles: 'Shock Pad'

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Jørgensen, Uffe, and Finn Bojsen-Møller. "Shock Absorbency of Factors in the Shoe/Heel Interaction—With Special Focus on Role of the Heel Pad." Foot & Ankle 9, no. 6 (June 1989): 294–99. http://dx.doi.org/10.1177/107110078900900607.

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The heel pad acts as a shock absorber in walking and in heel-strike running. In some patients, a reduction of its shock-absorbing capacity has been connected to the development of overuse injuries. In this article, the shock absorption of the heel pad as well as external shock absorbers are studied. Individual variation and the effect of trauma and confinement on the heel pad were specifically investigated. Drop tests, imitating heel impacts, were performed on a force plate. The test specimens were cadaver heel pads (n = 10); the shoe sole component consisted of ethyl vinyl acetate (EVA) foam and Sorbothane inserts. The shock absorption was significantly greater in the heel pad than in the external shock absorbers. The mean heel pad shock absorption was 1.1 times for EVA foam and 2.1 times for Sorbothane. The shock absorption varied by as much as 100% between heel pads. Trauma caused a decrease in the heel pad shock absorbency (24%), whereas heel pad confinement increased the shock absorbency (49% in traumatized heel pads and 29.5% in nontraumatized heel pads). These findings provide a biomechanical rationale for the clinical observations of a correlation between heel pad shock absorbency loss and heel strike-dependent overuse injuries. To increase shock absorbency, confinement of the heel pad should be attempted in vivo.

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Jørgensen, Uffe, Eilif Larsen, and Jens Erik Varmarken. "The HPC-Device: A Method to Quantify the Heel Pad Shock Absorbency." Foot & Ankle 10, no. 2 (October 1989): 93–98. http://dx.doi.org/10.1177/107110078901000208.

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Previous studies have indicated that the shock absorbency of the heel pad is significant in the pathophysiology of pain conditions connected with heel strike. The purpose of this study was to develop a simple clinically usable method for quantification of the heel pad shock absorbency. The results of our efforts was the HPC-device which consists of a fixing device and a transducer. The HPC-device was found suitable in the evaluation of the heel pad force/deformation characteristics. The reproducibility of heel pad deformation was 0.96. Tests of six cadaver heel pads revealed a high correlation between the HPC result and the shock absorbency found by drop tests. In a normal material (200 heel pads), it was found that the shock absorption decreased with age and that men had significantly higher shock absorbency than women. Men also had significantly thicker heel pads than women. However, there was no linear correlation between the thickness of the heel pad and the shock absorbency, although the thinnest heel pads had the lowest shock absorbency. The HPC-device was found clinically usable and will be used in further testing of the significance of heel pad shock absorption for the development of heel strike dependent over-use injuries.

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Peacock, Robert, and Gary Cordner. "“Shock Therapy” in Ukraine: A Radical Approach to Post-Soviet Police Reform." Public Administration and Development 36, no. 2 (May 2016): 80–92. http://dx.doi.org/10.1002/pad.1748.

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Jørgensen, Uffe. "Achillodynia and loss of heel pad shock absorbency." American Journal of Sports Medicine 13, no. 2 (March 1985): 128–32. http://dx.doi.org/10.1177/036354658501300209.

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Leffingwell, James W. "Unitary shock‐absorbing polymeric pad for artificial turf." Journal of the Acoustical Society of America 79, no. 6 (June 1986): 2104. http://dx.doi.org/10.1121/1.393141.

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Knight, Kathryn. "Shock-absorbing pad protects whales’ jaws when dining." Journal of Experimental Biology 223, no. 7 (April 1, 2020): jeb224642. http://dx.doi.org/10.1242/jeb.224642.

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Knight, Kathryn. "Retraction: Shock-absorbing pad protects whales’ jaws when dining." Journal of Experimental Biology 223, no. 12 (June 15, 2020): jeb230771. http://dx.doi.org/10.1242/jeb.230771.

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Nagarajan, Balasubramanian, Sylvie Castagne, Zhong Ke Wang, and Hong Yu Zheng. "Finite Element Analysis of the Effect of Flexible Pad on the Deformation of Metal Foils in Flexible Pad Laser Shock Microforming." Key Engineering Materials 611-612 (May 2014): 581–88. http://dx.doi.org/10.4028/www.scientific.net/kem.611-612.581.

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Flexible Pad Laser Shock Forming (FPLSF) is a new microforming process using laser-induced shock pressure and a flexible pad. This process involves high strain-rate (~105 s-1) plastic deformation of metallic foils along with the hyperelastic deformation of the flexible elastomer pad over which the foil is positioned. This paper studies the influence of flexible pad on the shockwave propagation behavior and the plastic deformation of metal foil in FPLSF using finite element analysis. The effect of flexible pad materials such as silicone rubber, polyurethane rubber and natural rubber on the deformation of copper foils has been analysed in detail. An increase in crater depth is observed with the reduction in flexible pad hardness. However, it is found that there exists an optimum hardness of the flexible pad to achieve perfect hemispherical craters on metal foils, as bending of foils at non-deformed region is observed with softer pads whereas flattening of crater surface occurs with harder pads. The effect of flexible pad thickness on the foil deformation was analyzed at six different thickness levels: 300 μm, 600 μm, 900 μm, 1200 μm, 1500 μm, and 2000 μm. Similarly, there exists an optimum flexible pad thickness to maximize the crater depth and achieve the hemispherical shapes. Analysis of flexible pad thickness indicates that the pad thickness influences the elastic recovery of the flexible-pad and hence the plastic deformation of the metallic foils.

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Collins, Paul, and Frederick Nixson. "Managing the implementation of ‘shock therapy’ in a landlocked state: Mongolia's transition from the centrally planned economy." Public Administration and Development 13, no. 4 (October 1993): 389–407. http://dx.doi.org/10.1002/pad.4230130407.

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Jung, Donghyuck, Changkyoo Park, Eun-Joon Chun, and Yoon-Jun Kim. "Improvement of Wear Resistance in Laser Shock-Peened Copper Contacts." Korean Journal of Metals and Materials 58, no. 8 (August 5, 2020): 560–65. http://dx.doi.org/10.3365/kjmm.2020.58.8.560.

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This study investigated the influence of laser shock peening without coating (LSPw/oC) on the degradation of copper electrical contacts. A theoretical calculation of the plastic-affected depth (PAD) induced by LSPw/oC was performed, based on the laser-induced plasma pressure along with the Hugoniot elastic limit of our LSPw/oC experimental conditions. The theoretical PAD was obtained approximately 650 µm from the surface for the LSPw/oC at the laser energy density of 5.3 GW/cm2. Various characterization methods such as the Vicker’s hardness test, residual stress test, and electron backscattered diffraction (EBSD) mapping indicated the PAD may play a significant role in laser induced effective depth for LSPw/oC. At a laser energy density of 5.3 GW/cm2, the laser shock-peened copper showed approximately double the surface hardness as compared to the pure copper. This was attributed to grain refinement, which was confirmed by measuring average grain sizes, and by observing mechanical twin structures from the EBSD analysis. Additionally, a compressive residual stress was induced down to the PAD but gradually switched to a tensile residual stress below PAD. The surface hardening effect conferred by LSPw/oC to the pure copper surface resulted in excellent wear resistance, i.e., a low coefficient of friction and wear loss. As a result, the contact exhibited lower electrical resistance following the fretting friction test compared to pure copper; this would result in a significant delay in electrical contact failure.

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Heidenfelder, Jens, Thorsten Sterzing, and Thomas L. Milani. "Systematically modified crash-pad reduces impact shock in running shoes." Footwear Science 2, no. 2 (June 2010): 85–91. http://dx.doi.org/10.1080/19424281003781543.

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Torney, Hannah, Olibhéar McAlister, Adam Harvey, Amy Kernaghan, Rebecca Funston, Ben McCartney, Laura Davis, Raymond Bond, David McEneaney, and Jennifer Adgey. "Real-world insight into public access defibrillator use over five years." Open Heart 7, no. 1 (June 2020): e001251. http://dx.doi.org/10.1136/openhrt-2020-001251.

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BackgroundPublic access defibrillators (PADs) represent unique life-saving medical devices as they may be used by untrained lay rescuers. Collecting representative clinical data on these devices can be challenging. Here, we present results from a retrospective observational cohort study, describing real-world PAD utilisation over a 5-year period.MethodsData were collected between October 2012 and October 2017. Responders voluntarily submitted electronic data downloaded from HeartSine PADs, and patient demographics and other details using a case report form in exchange for a replacement battery and electrode pack.ResultsData were collected for 977 patients (692 males, 70.8%; 255 females, 26.1%; 30 unknown, 3.1%). The mean age (SD) was 59 (18) years (range <1 year to 101 years). PAD usage occurred most commonly in homes (n=328, 33.6%), followed by public places (n=307, 31.4%) and medical facilities (n=128, 13.1%). Location was unknown in 40 (4.09%) events. Shocks were delivered to 354 patients. First shock success was 312 of 350 patients where it could be determined (89.1%, 95% CI 85.4% to 92.2%). Patients with reported response times ≤5 min were more likely to survive to hospital admission (89/296 (30.1%) vs 40/250 (16.0%), p<0.001). Response time was unknown for 431 events.ConclusionThis is the first study to report global PAD usage in voluntarily submitted, unselected real-world cases and demonstrates the real-world effectiveness of PADs, as confirmed by first shock success.

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Bultmann, Hermann. "Heat shock responses in polytene foot pad cells of Sarcophaga bullata." Chromosoma 93, no. 4 (March 1986): 347–57. http://dx.doi.org/10.1007/bf00327594.

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Yao, Huanling, Guojie Cao, Zheng Liu, Yue Zhao, Zhanchao Yan, Senzhen Wang, Yuehua Wang, Zhengwei Guo, and Yanming Wang. "Inhibition of Netosis with PAD Inhibitor Attenuates Endotoxin Shock Induced Systemic Inflammation." International Journal of Molecular Sciences 23, no. 21 (October 31, 2022): 13264. http://dx.doi.org/10.3390/ijms232113264.

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Neutrophils play a pivotal role in innate immunity by releasing neutrophils extracellular traps (NETs). Excessive NETs are detrimental to the local tissue and further exacerbate inflammation. Protein arginine deiminases (PAD) mediate histone citrullination and NET formation that, in turn, exacerbate endotoxin shock damages. In this study, we further investigated the molecular mechanism underlying PAD and NETs in endotoxic stress in mice. The control group mice were injected with solvent, the LPS endotoxic shock group mice were intraperitoneally injected with LPS at 35 mg/kg only, while the LPS and PAD inhibitor YW3-56 treatment group mice were injected with YW3-56 at 10 mg/kg prior to the LPS injection. YW3-56 significantly prolonged the survival time of the LPS-treated mice. NETs, cfDNA, and inflammatory factors were detected by ELISA in serum, paitoneal cavity, and lung at 24 h after LPS administration. Lung injuries were detected by immunostaining, and lung tissue transcriptomes were analyzed by RNA-seq at 24 h after LPS administration. We found that YW3-56 altered neutrophil tissue homeostasis, inhibited NET formation, and significantly decreased cytokines (IL-6, TNFα and IL-1β) levels, cytokines gene expression, and lung tissue injury. In summary, NET formation inhibition offers a new avenue to manage inflammatory damages under endotoxic stress.

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Chanda, Arnab, and Stephen McClain. "Mechanical Modeling of Healthy and Diseased Calcaneal Fat Pad Surrogates." Biomimetics 4, no. 1 (January 3, 2019): 1. http://dx.doi.org/10.3390/biomimetics4010001.

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The calcaneal fat pad is a major load bearing component of the human foot due to daily gait activities such as standing, walking, and running. Heel and arch pain pathologies such as plantar fasciitis, which over one third of the world population suffers from, is a consequent effect of calcaneal fat pad damage. Also, fat pad stiffening and ulceration has been observed due to diabetes mellitus. To date, the biomechanics of fat pad damage is poorly understood due to the unavailability of live human models (because of ethical and biosafety issues) or biofidelic surrogates for testing. This also precludes the study of the effectiveness of preventive custom orthotics for foot pain pathologies caused due to fat pad damage. The current work addresses this key gap in the literature with the development of novel biofidelic surrogates， which simulate the in vivo and in vitro compressive mechanical properties of a healthy calcaneal fat pad. Also, surrogates were developed to simulate the in vivo mechanical behavior of the fat pad due to plantar fasciitis and diabetes. A four-part elastomeric material system was used to fabricate the surrogates, and their mechanical properties were characterized using dynamic and cyclic load testing. Different strain (or displacement) rates were tested to understand surrogate behavior due to high impact loads. These surrogates can be integrated with a prosthetic foot model and mechanically tested to characterize the shock absorption in different simulated gait activities, and due to varying fat pad material property in foot pain pathologies (i.e., plantar fasciitis, diabetes, and injury). Additionally, such a foot surrogate model, fitted with a custom orthotic and footwear, can be used for the experimental testing of shock absorption characteristics of preventive orthoses.

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Benson, Mollie, Burton Carpenter, and Andrew Mawer. "Solder-Joint Reliability of a Radar Processor for Semi-Autonomous Driving Applications." International Symposium on Microelectronics 2018, no. 1 (October 1, 2018): 000104–9. http://dx.doi.org/10.4071/2380-4505-2018.1.000104.

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Abstract Radar is currently employed in automotive applications to provide the range, angle, and velocity of objects using RF waves (77GHz). This paper outlines solder joint reliability of a specific micro-processor that processes data received from a SRR (short range radar operating from 0.2 to 30 meters). It is a powerful digital signal processing accelerator, which targets safety applications that require a high Automotive Safety Integrity Level (ASIL-B). The paper explores the package design and construction, SMT (surface mount technology) assembly, and board level reliability testing of various BGA pad surface finish and solder ball alloy materials on a 0.65 mm pitch, 10 × 10 mm body 141 MAPBGA (mold array process-ball grid array) package. The package configurations include two BGA pad surface finishes (Ni/Au and OSP [organic solderability protectant]) and three solder alloys (SnAg, SAC405, and SAC-Bi [a Bi containing SAC derivative]). Solder joint reliability analysis was performed through AATS (air-to-air thermal shock) between 40°C and +125°C and JEDEC Drop Testing at 1500G's. Thermal shock was extended until at least 75% of the populations failed, which was well past the points needed to qualify the packages for the intended end-use applications. The evaluations of the micro-processor indicate that the MAPBGA package can meet the ASIL-B specification requirements with optimized combinations of BGA pad surface finish and solder alloy. The focus of this paper was to determine the baseline solder-joint thermal shock and JEDEC drop performance with varied BGA pad surface finish and solder ball alloy materials.

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Nagarajan, Balasubramanian, Sylvie Castagne, and Zhong Ke Wang. "Investigation of Copper Foil Thinning Behavior by Flexible-Pad Laser Shock Forming." Key Engineering Materials 535-536 (January 2013): 306–9. http://dx.doi.org/10.4028/www.scientific.net/kem.535-536.306.

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This paper reports on a novel microforming technique, Flexible-Pad Laser Shock Forming (FPLSF) which uses laser-induced shock waves and a flexible pad to induce plastic deformation on metallic foils. Thickness distribution at the cross-section of the craters formed by FPLSF is analyzed experimentally with respect to laser fluence, which is a significant process variable that controls the deformation pressure. Furthermore, hardness of the deformed samples at the cross-section is measured by nanoindentation testing. It is found that the thinning of copper foil by FPLSF ranges from 7% to 25% for laser fluence ranging between 7.3 J/cm2 and 20.9 J/cm2. Thinning is maximum at the crater center, which can be attributed to the maximum compressive stresses in the thickness direction, and minimum at the edge portions. With increase in laser fluence, thinning of the foil increases whereas minimum change in hardness is observed. The variation in thinning across different crater locations ranges between 6% and 8% only, which indicates that FDLSF can be developed as a competitive technique to produce components with uniform thickness distribution.

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Jørgensen, U., and J. Ekstrand. "Significance of Heel Pad Confinement for the Shock Absorption at Heel Strike." International Journal of Sports Medicine 09, no. 06 (December 1988): 468–73. http://dx.doi.org/10.1055/s-2007-1025053.

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KHANI, M. M., H. KATOOZIAN, K. AZMA, I. NASEH, and A. H. SALIMI. "HYPER-ELASTIC PARAMETER ESTIMATION OF HUMAN HEEL-PAD: A FINITE ELEMENT AND EVOLUTIONARY BASED ALGORITHM." Journal of Mechanics in Medicine and Biology 12, no. 03 (June 2012): 1250034. http://dx.doi.org/10.1142/s0219519411004708.

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The heel-pad as a biological shock absorber has an important role in the initial contact phase of gait cycle dissipating the impact forces resulted in locomotion. An axisymmetric finite element model of human heel-pad has been generated and the heel-pad experimental data deduced from a published force-deflection graph of the same specimen (Iain R. Spears, Janice E. Miller-Young), Iterative identification task has been used to extract nonlinear material properties describing hyper-elastic behavior of heel-pad. The genetic algorithm was incorporated into estimation process using an interface program. Two parameters of hyper-elastic materials potential energy function represented by Mooney–Rivlin were determined by using the genetic algorithm technique to minimize the displacement error between the experimental data and the corresponding finite element results after a considerable number of iterations. The result can be used for design and construction of synthetic heel-pad and therapeutic foot wear as well as insoles, especially for diabetic patients.

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Lee, Hyun-Kyu, Yong-Chul Chu, Myung-Ho Chun, and Sang-Ho Jeon. "A study of high Cu behavior on electrolytic Ni and electroless Ni pad finish." International Symposium on Microelectronics 2010, no. 1 (January 1, 2010): 000806–12. http://dx.doi.org/10.4071/isom-2010-tha2-paper4.

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It has been used various pad finish materials to enhance the reliability of solder joint and Electroless Ni Immersion Gold (the following : ENIG) pad has been used more than others. This study is about reliability according to being used in commercial Electrolytic Ni pad and ENIG pad, and was observed behavior of various Cu contents. After reflow, the inter-metallic compound (IMC) between solder and pad is composed of Cu6Sn5 (Ni substituted) by using EDS, and in case of ENIG, between IMC and Ni layer was observed the dark layer (Ni3P layer). Additional, it could be controlled the thickness of dark layer according to Cu contents. Investigated the different fracture mode between electrolytic Ni and ENIG pad after drop shock test, in case of soft Ni, accelerated stress propagated along the interface between 1st IMC and 2nd IMC, and in case of ENIG pad, accelerated stress propagated along the weaken surface such as dark layer. The unstable interface exists through IMC, pad material and solder bulk by the lattice mismatch, so that the thermal and physical stress due to the continuous exterior impact is transferred to the IMC interface. Therefore, it is strongly requested to control solder morphology, IMC shape and thickness to improve the solder reliability.

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Wang, Jun, Zhi-Wei Wang, Li-Xin Lu, Yong Zhu, and Yong-Guang Wang. "Three-Dimensional Shock Spectrum of Critical Component for Nonlinear Packaging System." Shock and Vibration 18, no. 3 (2011): 437–45. http://dx.doi.org/10.1155/2011/312063.

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To evaluate the shock characteristics of critical component for a nonlinear packaging system, a new concept of three-dimensional shock spectrum was proposed. Three key coordinate parameters, such as the nondimensional pulse duration, the frequency parameter ratio and the ratio of the maximum response acceleration to the peak pulse acceleration, were governed in a novel dynamical mathematical model. It is shown that the shock response of critical component is weakened owning to the decrease in the defined system parameter. Furthermore, at low frequency parameter ratio, the enhancement of the damping ratio of the critical component leads to the decrease in the peak of the shock response, which can also be reduced by the increase in damping ratio of cushioning pad at both lower and higher frequency parameter ratios. The discussion and analysis provide some insights into the design of cushioning packaging as well.

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Meyers, Michael C. "Surface-Related High School Football Game Injuries on Pad and No-Pad Fields." American Journal of Sports Medicine 49, no. 9 (July 2021): 2489–97. http://dx.doi.org/10.1177/0363546521990780.

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Background: Artificial turf fields are increasingly being installed with lighter weight infill systems that incorporate a pad underlayer, which is reported to reduce surface shock and decrease injuries. At this time, the effects of a pad underlayer on football trauma are unknown. Hypothesis: Athletes would not experience differences in surface-related injuries between pad and no-pad fields. Study Design: Cohort study; Level of evidence, 2. Methods: Artificial turf fields were divided into 2 groups based on a pad underlayer or no-pad system, with 58 high schools participating across 3 states over the course of 7 seasons. Outcomes of interest included injury severity, head and knee trauma, injury category, primary type of injury, injury mechanism, anatomic location of trauma, tissue type injured, and elective imaging and surgical procedures. Data underwent multivariate analyses of variance (MANOVA) using general linear model procedures and were expressed as injury incidence rates per 10-game season. Results: Of 658 varsity games, 260 games were played on fields containing pads, and 398 games were played on no-pad fields, with 795 surface-related injuries reported. MANOVA indicated significant main effects by injury severity ( F3,791 = 11.436; P < .0001), knee trauma ( F9,785 = 2.435; P = .045), injury category ( F3,791 = 3.073; P < .0001), primary type of injury ( F10,785 = 2.660; P < .0001), injury mechanism ( F13,781 = 2.053; P < .001), anatomic location ( F16,778 = 1.592; P < .001), type of tissue injured ( F4,790 = 4.485; P < .0001), and elective imaging and surgical procedures ( F4,790 = 4.248; P < .002). Post hoc analyses indicated significantly greater incidences ( P < .05) of substantial and severe injury, player-to-turf trauma, patellofemoral syndrome, neck strain, lower leg strain, and elective imaging and surgical procedures when games were played on padded turf fields. No differences in concussion rate from turf impact between pad and no-pad fields were observed. Conclusion: In contrast to conventional wisdom, the addition of a pad under an artificial turf surface increases injury rates when compared with nonpadded fields across most injury categories. At this time, findings do not support the current trend of installing lightweight padded infill systems at the high school level of play.

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Jiang, Jiu Hong, and Jun Wang. "Combined Shock Response Spectrum of Cubic Nonlinear Stacking Packaging System." Applied Mechanics and Materials 66-68 (July 2011): 245–49. http://dx.doi.org/10.4028/www.scientific.net/amm.66-68.245.

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The shock characteristics of a cubic nonlinear stacking packaging system were investigated under the action of half-sine acceleration pulse. The dynamical model of the system was developed, and the numerical results of the dynamical equations were obtained. Based on the results, a new concept of combined shock response spectrum was proposed to describe the shock characteristics of cubic stacking packaging system, focusing more on the maximum of the peak response acceleration of all products at all sensitive frequency since the damage of stacking packaging system occurs when any of the products was damaged. And it’s found that the combined shock spectrum is always made up of the shock spectrum of the bottom layer at lower dimensionless pulse duration and the shock spectrum of the top layer at higher dimensionless pulse duration. Then, the effect of the peak pulse acceleration, the defined system parameter, the damping ratio of cushioning pad in addition to the number of stacking layers on the combined shock spectrum of the system was discussed. It’s shown that all of their effect are noticeable. The results lead to some insights into the design of cushioning packaging.

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Özdemır, Hakan, Yetkın Söyüncü, Mete Özgörgen, and Kürşat Dabak. "Effects of Changes in Heel Fat Pad Thickness and Elasticity on Heel Pain." Journal of the American Podiatric Medical Association 94, no. 1 (January 1, 2004): 47–52. http://dx.doi.org/10.7547/87507315-94-1-47.

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The heel fat pad has a unique structure that is important for its shock-absorbing function. Loss of elasticity and changes in the thickness of the heel pad have been suggested as causes of heel pain. The present study of a population with heel pain shows the relationship between the thickness and elasticity of the heel fat pad and age, sex, obesity, duration of symptoms, subcalcaneal spurs, and noninvasive conservative treatment. Of 182 patients with heel pain who visited an outpatient clinic during a 3-year period, 50 (67 heels) fulfilling specific criteria were treated with a combination of nonsteroidal anti-inflammatory drugs, contrast baths, stretching exercises, and change of footwear habits. Patients were followed up for 1 year. Delayed healing, increased thickness, and decreased elasticity of the heel fat pad were found in patients who were older than 40 years, who had symptoms for longer than 12 months before treatment, and who had a large subcalcaneal spur. An increase in heel fat pad thickness with aging and increased body weight reduce the elasticity of the heel fat pad. In addition, subcalcaneal spurs diminish the elasticity of the heel fat pad and play a role in the formation of heel pain. (J Am Podiatr Med Assoc 94(1): 47-52, 2004)

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White, James. "Design of Optimized Opposed Slider Air Bearings for High-Speed Recording on a Metal Foil Disk." Journal of Tribology 128, no. 2 (November 3, 2005): 327–34. http://dx.doi.org/10.1115/1.2162917.

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A metal foil disk offers some of the best characteristics of both the hard disk and floppy disk for digital data storage. The current work defines an opposed slider air-bearing arrangement that provides advantages when used with a high-speed metal foil disk in either a fixed or removable format. Use is made of the fact that the opposing sliders interact through their influence on the flexible disk that is sandwiched between them. Asymmetry of opposing air bearings is created by etching the air-bearing pad opposite the recording element pad to a depth sufficient that the flying height and air film stiffness of the opposing pad reach desired levels. The result is an air-bearing interface with low flying height and high stiffness over the recording element directly opposed by a high flying height and low stiffness on the other side of the disk. This air-bearing interface was found to provide an enhanced dynamic flexibility to the metal foil disk when it is subjected to mechanical shock. As a result, the opposed slider arrangement with metal foil disk is able to avoid contact and impact when subjected to substantial levels of mechanical shock. Thus, wear and damage to slider and disk surfaces are reduced as well as the possibility of lost recorded data. This should make the metal foil disk a strong candidate as a rotating storage medium for mobile and portable applications where a shock environment is common. Computer simulation of the new air-bearing configuration will be presented and discussed. The current work is related to but distinct from that reported recently by White (2005, ASME J. Tribol., 127, pp. 522–529) for a Mylar disk.

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Zeng, Zhiping, Di Wang, Fushan Liu, Abdulmumin A. Shuaibu, and Zhihua Lin. "Experimental Study on the Sliding of WJ-8 Small Resistance Fastener Composite Pad." Advances in Civil Engineering 2020 (August 3, 2020): 1–8. http://dx.doi.org/10.1155/2020/1918043.

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Under long-term temperature loading, long bridges stretch and deform, causing the beam and rail to move relative to each other. This phenomenon could cause a gradual slide of the rail relative to the fastener composite pad and ultimately results in the slipping out of the fastener pad at the end of the ballastless track bridge changes. The slipping out of the fastener composite pad changes the longitudinal resistance of the fastener and causes shock of the train on the rail structure due to direct contact between the rail and the tie, thus inhibiting the normal use of the line. In this paper, a reciprocating tensile test was carried out on a WJ-8 small resistance fastener to explore the breaking process of the fastener composite pad, identify the interaction mechanism of the fastener composite pad under the rail, and ultimately determine the influence of the pad on the longitudinal resistance of the fastener. The results show that the two factors that affect the longitudinal resistance of the fastener under reciprocating loading are the surface roughness and displacement of the fastener composite pad. While the surface roughness of the fastener composite pad is the main influencing factor in the early stage, the displacement of the composite pad has a greater impact on the later stage. The research results of this paper can provide an important reference for the maintenance and repair of ballastless track fasteners on bridges.

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Noh, Bo In, and Seung Boo Jung. "Reliability of Flip Chip Package with Underfills under Thermal Shock." Key Engineering Materials 321-323 (October 2006): 1719–22. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1719.

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The thermal fatigue properties of the solder joints with various underfills were evaluated by thermal shock test. Flip chip package with electroless nickel-immersion gold plated on Cu pad of FR-4 substrate and the Sn-37Pb solder ball was used. The thermal fatigue crack initiated at the edges of interface between solder and silicon die. The fatigue property of package with underfill, which has a higher glass transition temperature (Tg) and lower coefficient of thermal expansion (CTE) value was better than that of package with underfill having a lower Tg and higher CTE.

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Costa, Nara Aline, Bertha Furlan Polegato, Amanda Gomes Pereira, Sérgio Alberto Rupp de Paiva, Ana Lúcia Gut, André Luís Balbi, Daniela Ponce, Leonardo Antonio Mamede Zornoff, Paula Schmidt Azevedo, and Marcos Ferreira Minicucci. "Evaluation of peptidylarginine deiminase 4 and PADI4 polymorphisms in sepsis-induced acute kidney injury." Revista da Associação Médica Brasileira 66, no. 11 (November 2020): 1515–20. http://dx.doi.org/10.1590/1806-9282.66.11.1515.

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SUMMARY BACKGROUND: The aim of this study is to evaluate the peptidylarginine deiminase 4 (PAD 4) concentration and PADI4 polymorphisms as predictors of acute kidney injury (AKI) development, the need for renal replacement therapy (RRT), and mortality in patients with septic shock. METHODS: We included all individuals aged ≥ 18 years, with a diagnosis of septic shock at ICU admission. Blood samples were taken within the first 24 hours of the patient's admission to determine serum PAD4 concentration and its PADI4 polymorphism (rs11203367) and (rs874881). Patients were monitored during their ICU stay and the development of SAKI was evaluated. Among the patients in whom SAKI developed, mortality and the need for RRT were also evaluated. RESULTS: There were 99 patients, 51.5% of whom developed SAKI and of these, 21.5% needed RRT and 80% died in the ICU. There was no difference between PAD4 concentration (p = 0.116) and its polymorphisms rs11203367 (p = 0.910) and rs874881 (p = 0.769) in patients in whom SAKI did or did not develop. However, PAD4 had a positive correlation with plasma urea concentration (r = 0.269 and p = 0.007) and creatinine (r = 0.284 and p = 0.004). The PAD4 concentration and PADI4 polymorphisms were also not associated with RRT and with mortality in patients with SAKI. CONCLUSION: PAD4 concentration and its polymorphisms were not associated with SAKI development, the need for RRT, or mortality in patients with septic shock. However, PAD4 concentrations were associated with creatinine and urea levels in these patients.

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Wang, Yan, Hua Wang, and Cunyan Cui. "The effect on the shock wave resulting from the rocket explosion on launch pad." IOP Conference Series: Earth and Environmental Science 358 (December 13, 2019): 042016. http://dx.doi.org/10.1088/1755-1315/358/4/042016.

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Nagarajan, Balasubramanian, Sylvie Castagne, Zhongke Wang, and H. Y. Zheng. "EBSD analysis of plastic deformation of copper foils by flexible pad laser shock forming." Applied Physics A 121, no. 2 (September 4, 2015): 695–706. http://dx.doi.org/10.1007/s00339-015-9460-1.

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Wang, Xiao, Liyin Li, Zongbao Shen, Chaofei Sha, Shuai Gao, Cong Li, Xianqing Sun, Youjuan Ma, and Huixia Liu. "Experimental investigation on: Laser shock micro-forming process using the mask and flexible pad." Optics and Lasers in Engineering 88 (January 2017): 102–10. http://dx.doi.org/10.1016/j.optlaseng.2016.08.003.

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Nagarajan, Balasubramanian, Sylvie Castagne, Zhongke Wang, H. Y. Zheng, and Kartikeyan Nadarajan. "Influence of plastic deformation in flexible pad laser shock forming – experimental and numerical analysis." International Journal of Material Forming 10, no. 1 (September 4, 2015): 109–23. http://dx.doi.org/10.1007/s12289-015-1264-5.

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Sears, George, Guoyun Tian, Duy Le, and Heather Bradley. "LORD SolderBrace™ Wafer Applied Coating for Improved Reliability and Throughput in WLCSP." International Symposium on Microelectronics 2013, no. 1 (January 1, 2013): 000055–60. http://dx.doi.org/10.4071/isom-2013-ta25.

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As more manufacturers look to increase the size of Wafer Level Chip Scale Package (WLCSP) dies and also look to decrease the ball pitch, the susceptibility of the die to fail during thermal cycling and drop shock testing increases. The stress conditions introduced during thermal cycling from the mismatches in Coefficients of Thermal Expansion (CTE) lead to solder fatigue. The failure of WLCSPs during drop shock is found at the solder/pad interface. The general solution to address solder fatigue during thermal cycling and solder joint stress at the copper pad interface has been capillary underfilling the chips after chip attachment. To address these issues, a new material from LORD Corporation – SolderBrace™ wafer applied coating, can be used to partially underfill the WLCSP die at the wafer level. This type of technology can be applied using existing equipment and processing techniques making these materials a more cost effective solution. This new material technology has enabled thermal cycling reliability improvements by replacing the final passivation layer with a new low CTE material as the partial underfill. This wafer applied partial underfill material technology has been successfully used to provide increased thermal cycling and drop shock reliability in WLCSPs using a number of different methods that have been previously described. The method to be discussed in this paper is a production process using a screen printed, photo defined polymer system that does not require any in-process post cure.

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Yu, Hai-Bin, Rui Zhang, Guo-Long Yu, Hai-Tao Wang, Dao-Chen Wang, Wei-Hsun Tai, and Jian-Long Huang. "A New Inspiration in Bionic Shock Absorption Midsole Design and Engineering." Applied Sciences 11, no. 20 (October 17, 2021): 9679. http://dx.doi.org/10.3390/app11209679.

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Inspired by the performance of the ostrich in terms of loading and high-speed moving ability, the purpose of this study was to design a structure and material on the forefoot and heel of the middle soles of sports shoes based on the high cushioning quality of the ostrich toe pad by applying bionic engineering technology. The anatomical dissection method was used to analyze the ostrich foot characteristics. The structure and material of the bionic shock absorption midsole were designed according to the principles of bionic engineering and reverse engineering. F-Scan and numerical simulation were used to evaluate the bionic shock absorption midsole performance. The results showed that the bionic shock absorption midsole decreased the peak pressure (6.04–12.27%), peak force (8.62–16.03%), pressure–time integral (3.06–12.66%), and force–time integral (4.06–10.58%) during walking and brisk walking. In this study, the biomechanical effects to which the bionic shock absorption midsole structure was subjected during walking and brisk walking exercises were analyzed. The bionic midsole has excellent shock resistance. It is beneficial for the comfort of the foot during exercise and might reduce the risk of foot injuries during exercise.

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Ker, R. F., M. B. Bennett, R. McN Alexander, and R. C. Kester. "Foot Strike and the Properties of the Human Heel Pad." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 203, no. 4 (December 1989): 191–96. http://dx.doi.org/10.1243/pime_proc_1989_203_038_01.

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Many force-plate records of human locomotion show an impulse (the foot strike) shortly after ground contact. The authors' hypothesis is that this results from the rapid deceleration of a mass (the ‘effective foot’) under forces which compress the heel pad. The quantitative implications are investigated through an illustrative calculation. The observations used are (a) the peak force reached in foot strike (b) the vertical velocity of the foot immediately before ground contact and (c) the properties of the heel pad in compression. Data for (a) and (b) are available in the literature; measurements for (c) are presented here. The deductions are: (a) the time taken to reach peak force is about 5.4 ms, which agrees with published measurements; (b) the mass of the effective foot is about 3.6 kg. The effective foot thus includes a substantial portion of the leg: this seems reasonable. The models used for the calculations clarify the relationship between the foot strike and the shock wave, which it generates.

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Williams, HLM, SA Jones, C. Lyons, C. Wilson, and A. Ghandour. "Refractory patella tendinopathy with failed conservative treatment—shock wave or arthroscopy?" Journal of Orthopaedic Surgery 25, no. 1 (January 1, 2017): 230949901668470. http://dx.doi.org/10.1177/2309499016684700.

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Aim: To identify whether the location of refractory patella tendinopathy (PT) has an effect on treatment modality (radial extracorporeal shock wave therapy (rESWT) or arthroscopic debridement). Methods: Between 2012 and 2014, 40 patients with PT underwent a magnetic resonance imaging (MRI) scan. This confirmed the diagnosis as either involving the tendon itself (group A, 20) or with retropatella fat pad extension (group B, 20). All patients underwent rESWT. If there was no improvement patients proceeded with surgery in the form of arthroscopic debridement (by senior authors CW and AG). Outcomes were assessed before and after treatment using the Victorian Institute of Sports Assessment-Patella (VISA-P) score. Results: There were 18 males and 2 females in group A and 15 males and 5 females in group B. The mean age was 41.4 years in group A (23–59) and 34.7 in group B (19–52). Seventeen of 20 in group A reported good or excellent outcomes and did not require surgical intervention (remaining three improved after second course of ESWT). All patients in group B failed to improve with rESWT, resulting in arthroscopic debridement and reported good or excellent outcomes. After 6 months, group A mean VISA-P score increased from 50.2 to 65.0 ( p = 0.01) and group B from 39.6 to 78.4 ( p = <0.001). Conclusion: An MRI should be performed to determine the precise location of tendinosis in patients with refractory PT who fail standard conservative management. If the MRI scan shows intratendon changes only, ESWT should be performed and those with extension into the fat pad should proceed to arthroscopic debridement without rESWT.

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Zhang, Songning, Thomas Elvidge, and Kevin Valenzuela. "Effects of Shock Pad and Synthetic Turf on Ankle Biomechanics in a 90° Cutting Movement." Medicine & Science in Sports & Exercise 51, Supplement (June 2019): 776. http://dx.doi.org/10.1249/01.mss.0000562815.22006.d6.

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Felder, S. L., and M. Davis. "LO37: Routine application of defibrillation pads and time to first shock in prehospital STEMI complicated by cardiac arrest." CJEM 19, S1 (May 2017): S40. http://dx.doi.org/10.1017/cem.2017.99.

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Introduction: ST-segment elevation myocardial infarction (STEMI) remains a significant cause of morbidity and mortality in North America, with recent studies suggesting that between 4 to 11% of patients diagnosed with STEMI suffer an out-of-hospital-cardiac arrest (OHCA). Previously published research has shown that shorter time to initial defibrillation in patients with VF/VT OHCA increases functional survival. The purpose of this study is to assess whether the routine application of defibrillation pads in STEMI decreases the time to initial defibrillation in those who suffer OHCA. Methods: Ambulance call records (ACR) for patients diagnosed with STEMI in Middlesex-London in the prehospital setting from Jan 1, 2012 to Jun 30, 2016 were reviewed. Patients were included in the study if they were 18 years of age or older with a confirmed diagnosis of STEMI and suffered an OHCA with an initial shockable rhythm (VF or VT) while in paramedic care. The pre-pad protocol (routine application of defibrillation pads in STEMI patients) was implemented by Middlesex-London EMS in July 2014. If inclusion criteria were met, ACRs were reviewed to determine whether the pre-pad protocol was implemented and to extract the time to initial defibrillation and relevant demographic and event features. Associated hospital charts were reviewed to evaluate inpatient event features and survival. T-test was used to assess the difference between mean times to defibrillation. Results: 446 patients were diagnosed with prehospital STEMI. Of those, 11 patients experienced a paramedic witnessed cardiac arrest. Four of the 11 had defibrillation pads applied upon diagnosis of STEMI. In patients who received pre-pad application, the mean time to initial defibrillation was 17.71 sec, compared to 72.71 sec in patients who had pads applied following arrest (MD 54.97 sec CI 22.69 to 87.24 sec). All patients treated with the pre-pad protocol survived to discharge from hospital, while one patient in the routine care group died in the ED. Conclusion: Routine application of defibrillation pads decreases the time to initial defibrillation in STEMI patients who suffer OHCA. Larger studies are required to evaluate whether this decreased time to defibrillation translates into mortality benefit in this subset of patients who experience OHCA.

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James, Isaac B., Beth R. Gusenoff, Sheri Wang, Gabriella DiBernardo, Danielle Minteer, and Jeffrey A. Gusenoff. "A Step in the Right Direction: A Prospective Randomized, Controlled Crossover Trial of Autologous Fat Grafting for Rejuvenation of the Heel." Aesthetic Surgery Journal 41, no. 7 (February 22, 2021): NP959—NP972. http://dx.doi.org/10.1093/asj/sjab095.

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Abstract Background The shock-absorbing soft tissues of the heel are composed of dermis and specialized fat pads. Heel fat pad atrophy is common and can be painful and debilitating. In our previous work, autologous fat grafting was effective for treating pain from forefoot fat pad atrophy. Objectives The authors hypothesized that autologous fat grafting to the heel would relieve pain and improve function in patients with heel fat pad atrophy. Methods Patients with heel fat pad atrophy and associated pain were recruited and randomized into 2 groups. Group 1 received autologous fat grafting on enrollment and was followed for 2 years. Group 2 received offloading and activity modification for 1 year, then crossed over, underwent autologous fat grafting, and was followed for 1 year afterward. Outcome measures included ultrasound-measured fat pad and dermal thickness; pedobarograph-measured foot pressures and forces; and patient-reported outcomes as measured by the Manchester Foot Pain and Disability Index. Results Thirteen patients met the inclusion criteria and completed the study. Seven (12 affected feet) were randomized into Group 1; and 6 (9 affected feet) were randomized into Group 2. The average age was 55 years and BMI was 30.5 kg/m2. Demographics did not significantly differ between groups. Heel fat pad thickness increased after autologous fat grafting but returned to baseline at 6 months. However, autologous fat grafting increased dermal thickness significantly and also increased fat pad thickness under a compressive load compared with controls at 6 and 12 months. Foot pain, function, and appearance were also significantly improved compared with controls at 6 and 12 months. Conclusions Autologous fat grafting improved patient-reported foot pain, function, and appearance and may rejuvenate local soft tissues in patients with heel fat pad atrophy. Level of Evidence: 3

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Meyers, Michael. "Surface-Related High School Football Game Injuries on Pad and No Pad Fields (101)." Orthopaedic Journal of Sports Medicine 9, no. 10_suppl5 (October 1, 2021): 2325967121S0025. http://dx.doi.org/10.1177/2325967121s00251.

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Objectives: Today’s new generations of artificial turf infill systems are increasingly being installed with lighter weight infill systems, which often incorporate interlocking polypropylene or thermoelastomer pad systems under the fiber-infill layers, reportedly to reduce surface shock, decrease concussions, and enhance shoe: surface stability. At this time, however, the effects of pad systems on high school football trauma during game conditions are unknown. With more than one million athletes playing competitive football, the rise in medical costs, and the increasing popularity of base pads being installed today as an alternative to heavier infill weight systems, this study focused on quantifying the potential influence of this practice on the incidence, mechanisms, and severity of game-related, high school varsity football injuries. Methods: Artificial turf playing fields were divided into two groups based on a pad underlayer or a no pad system. Fifty-eight high schools participated across three states over 7 seasons. Outcomes of interest included injury severity, injury category, primary type of injury, injury mechanism, anatomical location of trauma, type of tissue injured, and elective imaging/surgical procedures. Data were subject to multivariate analyses of variance (MANOVA) and Wilks’ λ criteria using general linear model procedures. Data were expressed as injury incidence rates (IIR) per 10 game season. Results: Of 658 varsity games documented, 260 games were played on fields containing pads, and 398 on no-pad fields, with 795 total injuries reported. MANOVA indicated a significant main effect across pad and no pad playing surfaces by injury severity (F3,791 = 11.436; P < .0001), knee trauma (F9,785 = 2.435; P = .045), injury category (F3,791 = 3.073; P < .0001), primary type of injury (F10,785 = 2.660; P < .0001), injury mechanism (F13,781 = 2.053; P < .001), anatomical location of trauma (F16,778 = 1.592; P < .001), type of tissue injured (F4,790 = 4.485; P < .0001), and elective imaging and surgical procedures (F4,790 = 4.248; P < .002). Post hoc analyses indicated significantly higher ( P < .05) substantial injury [10.3, (95% CI, 10.0-10.5) vs 3.0 (2.5-3.4)], player-to turf trauma [6.5, (95% CI, 5.9-7.1) vs 2.0 (1.6-2.4)], patellofemoral syndrome [1.3, (95% CI, 0.9-1.7) vs 0.3 (0.2-0.5)], neck strain [2.0, (95% CI, 1.5-2.5) vs 0.3 (0.2-0.5)], lower leg strain [3.9, (95% CI, 3.3-4.5) vs 1.1 (0.8-1.4)], and a higher number of lower extremity elective imaging and surgical procedures requested [7.2, (95% CI, 6.7-7.7) vs 3.2 (2.8-3.7)] when competing on artificial turf fields with pads as compared to no pad systems, respectively. In regard to reducing the frequency of concussions, there was no significant difference in concussion rate attributed to turf impact [0.3, (95% CI, 0.2-0.6) vs 0.1 (0.1-0.3)] between pad and no pad fields, respectively. Conclusions: The addition of a pad under an artificial turf surface increases injury rates when compared to non-pad fields across most injury categories. At this time, findings do not support the current trend of installing lightweight padded infill systems at the high school level of play. This is the first longitudinal study to investigate the influence of a pad on sport trauma, when integrated with an artificial turf infill system.

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Jiang, Jiuhong, and Jinzhi Zhou. "The Shock Response Spectrum of Two Degree-of-freedom System Dropping on the Expandable Polyethylene Pad." Research Journal of Applied Sciences, Engineering and Technology 06, no. 24 (December 25, 2013): 4548–52. http://dx.doi.org/10.19026/rjaset.6.3465.

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Jiang, Jiuhong, and Jinzhi Zhou. "The Shock Response Spectrum of Two Degree-of-Freedom System Dropping on the Expandable Polyethylene Pad." Research Journal of Applied Sciences, Engineering and Technology 6, no. 15 (August 20, 2013): 2724–28. http://dx.doi.org/10.19026/rjaset.6.3777.

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Nagarajan, Balasubramanian, Zhongke Wang, Sylvie Castagne, and Hongyu Zheng. "Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera." Applied Surface Science 308 (July 2014): 221–29. http://dx.doi.org/10.1016/j.apsusc.2014.04.139.

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Bultmann, Hermann. "Induction of a heat shock puff by hypoxia in polytene foot pad chromosomes of Sarcophaga bullata." Chromosoma 93, no. 4 (March 1986): 358–66. http://dx.doi.org/10.1007/bf00327595.

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Noe, D. A., S. J. Voto, M. S. Hoffmann, M. J. Askew, and I. A. Gradisar. "Role of the calcaneal heel pad and polymeric shock absorbers in attenuation of heel strike impact." Journal of Biomedical Engineering 15, no. 1 (January 1993): 23–26. http://dx.doi.org/10.1016/0141-5425(93)90088-g.

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Kim, Yong-Woon, Jae-Kyeong Jang, Jung-Ryul Lee, and Hak-Seong Gim. "Hybrid Method of Modal Analysis and Laser Shock Scanning to Visualize the Pyroshock Propagation in a Tension Joint." Shock and Vibration 2019 (August 27, 2019): 1–13. http://dx.doi.org/10.1155/2019/4389595.

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The use of pyrodevices in the aerospace industry has been increasing because of their ability to implement separation missions with a small weight, for example, space launchers, spacecrafts, and missiles. During operation, pyrodevices generate pyroshock, which causes failures of electronic devices. Recently, a pyroshock simulation method using laser shock has been developed to evaluate the risk of pyroshock before flight mission. However, depending on the structure, the laser shock showed some difficulty simulating pyroshock in the low-frequency regime accompanying vibration. Therefore, in this study, we developed a hybrid method of numerical modal analysis and laser shock-based experimental simulation to visualize the pyroshock propagation in all the relevant frequency regimes. For the proof of concept of the proposed method, we performed experiments of explosive bolt-induced shock and pyrolock-induced shock in the open-box-type tension joint and compared the hybrid simulation results with actual pyroshock. From the results, we obtained the simulated time-domain signal with an averaged peak-to-peak acceleration difference (PAD) of 11.2% and the shock response spectrum (SRS) with an averaged mean acceleration difference (MAD) of 28.5%. In addition, we were able to visualize the simulation results in the temporal and spectral domains to compare the pyroshock induced by each pyrodevice. A comparison of the simulations showed that the pyrolock had an impulse level of 1/12 compared to the explosion bolt. In particular, it was confirmed that the pyrolock-induced shock at the near field can cause damage to the electronic equipment despite a smaller impulse than that of the explosive bolt-induced shock. The hybrid method developed in this paper demonstrates that it is possible to simulate pyroshock for all the frequency regimes in complex specimens and to evaluate the risk in the time and frequency domain.

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Sanborn, Brett, Bo Song, and Scott Smith. "Pre-strain Effect on Frequency-Based Impact Energy Dissipation through a Silicone Foam Pad for Shock Mitigation." Journal of Dynamic Behavior of Materials 2, no. 1 (December 29, 2015): 138–45. http://dx.doi.org/10.1007/s40870-015-0043-1.

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Wu, Xueqing, Baoqing Pei, Yuyang Pei, Yan Hao, Kaiyuan Zhou, and Wei Wang. "Comprehensive Biomechanism of Impact Resistance in the Cat’s Paw Pad." BioMed Research International 2019 (July 31, 2019): 1–9. http://dx.doi.org/10.1155/2019/2183712.

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Cats are able to jump from a high-rise without any sign of injury, which is attributed in large part to their impact-resistant paw pads. The biomechanical study of paw pads may therefore contribute to improving the impact resistance of specific biomimetic materials. The present study is aimed at investigating the mechanics of the paw pads, revealing their impact-resistant biomechanism from macro- and microscopic perspectives. Histological and micro-CT scanning methods were exploited to analyze the microstructure of the pads, and mechanical testing was conducted to observe the macroscopic mechanical properties at different loading frequencies. Numerical micromodels of the ellipsoidal and cylindrical adipose compartments were developed to evaluate the mechanical functionality as compressive actions. The results show that the stiffness of the pad increases roughly in proportion to strain and mechanical properties are almost impervious to strain rate. Furthermore, the adipose compartment, which comprises adipose tissue enclosed within collagen septa, in the subcutaneous tissue presents an ellipsoid-like structure, with a decreasing area from the middle to the two ends. Additionally, the finite element results show that the ellipsoidal structure has larger displacement in the early stage of impact, which can absorb more energy and prevent instability at touchdown, while the cylindrical structure is more resistant to deformation. Moreover, the Von Mises of the ellipsoidal compartment decrease gradually from both ends to the middle, making it change to a cylindrical shape, and this may be the reason why the macroscopic stiffness increases with increasing time after contact. This preliminary investigation represents the basis for biomechanical interpretation and can accordingly provide new inspirations of shock-absorbing composite materials in engineering.

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Lo, Wei-Jung, Wei-Jhong Chen, Chih-Hung Lai, Yu-Wei Chen, Chieh-Shou Su, Wei-Chun Chang, Chi-Yan Wang, Tsun-Jui Liu, Kae-Woei Liang, and Wen-Lieng Lee. "Rotablation in Patients with Advanced Renal Insufficiency through End-Stage Renal Disease: Short- and Intermediate-Term Results." Journal of Interventional Cardiology 2022 (March 10, 2022): 1–10. http://dx.doi.org/10.1155/2022/7884401.

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Objective. Patients with advanced renal insufficiency are at high risk of coronary artery disease (CAD) and complex lesions. Treating complex calcified lesion with rotational atherectomy (RA) in these patients might be associated with higher risks and poorer outcomes. This study was set to evaluate features and outcomes of RA in these patients. Method. Consecutive patients who received coronary RA from April 2010 to April 2018 were queried from the Cath Lab database. The procedural details, angiography, and clinical information were reviewed in detail. Results. A total of 411 patients were enrolled and divided into Group A (baseline serum creatinine <5 mg/dl, n = 338) and Group B (baseline serum creatinine ≥ 5 mg/dl through ESRD, n = 73). Most patients had high-risk features (65.7% of acute coronary syndrome (ACS), 14.1% of ischemic cardiomyopathy, and 5.1% of cardiogenic shock). Group B patients were significantly younger (66.8 ± 11.4 vs. 75.2 ± 10.7 years, p < 0.001 ) and had more RCA and LCX but less LAD treated with RA. No difference was found in lesion location, vessel tortuosity, bifurcation lesions, chronic total occlusion, total lesion length, or total lesion numbers between the two groups. Less patients in Group B obtained completion of RA (95.9% vs 99.1%, p = 0.037 ). There was no difference in the incidence of procedural complication or acute contrast-induced nephropathy. Group B patients had more deaths and MACE while in the hospital. The MACE and CV MACE were also higher in Group B patients at 180 days and one year, mostly due to TLR and TVR. Multivariate regression analysis showed that ACS, age, peripheral artery disease (PAD), advanced renal insufficiency, ischemic cardiomyopathy/shock, and high residual SYNTAX score were independent risk factors for in-hospital MACE, whereas ACS, advanced renal insufficiency, ischemic cardiomyopathy/shock, triple-vessel disease, and PAD independently predicted MACE at 6 months. Conclusions. Rotablation is feasible, safe, and could be carried out with very high success rate in very-high-risk patients with advanced renal dysfunction through ESRD without an increase in procedural complication.

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Ma, Xiaogang, Jian Fan, Yunkai Wu, Xiaowei Liu, and Rui Xue. "Study on the mechanism of shock wave and boundary layer interaction control using high-frequency pulsed arc discharge plasma." Physics of Fluids 34, no. 8 (August 2022): 086102. http://dx.doi.org/10.1063/5.0095487.

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This paper studies the response characteristics of shock wave and boundary layer interaction (SWBLI) controlled by high-frequency pulsed arc discharge (PAD) in a Mach 2.5 flow. The dynamic evolution of SWBLI disturbed by arc plasma energy deposition was captured, and the controlling mechanism under different exciting power and frequency was explored. The results showed that the blast wave induced by PADs had a strong impact on SWBLI structures and distorted the separation shock wave. During the downstream propagation, the controlling gas bubbles (CGBs) delivered a continuous thermal excitation to the boundary layer and reached the maximum penetration depth near the semi-cylinder. The arc discharge in the SWBLI region induced larger energy deposition, which made the heating zone obtain the highest initial temperature and longest heating duration. Under the plasma condition of 1 × 1011 W/m3/15 kHz, both the upstream part of the shear layer and the foot portion of the reattachment shock wave were removed. When setting the excitation to 2.5 × 1010 W/m3/60 kHz, a thermal exciting surface of merged CGBs was formed and the separation shock wave was completely replaced by an equivalent compression-wave system. A better drag-reduction effect on the flow field would be produced by the actuator with an increased operating power or frequency, and a drag reduction rate of nearly 25.5% was achieved under the 2.5 × 1010 W/m3/60 kHz control condition.

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Journal articles on the topic 'Shock Pad'

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